semiconductor laser device

Abstract

To reduce an effect of an inverse electromotive voltage due to an inductance of a semiconductor laser device imposed on a control voltage of a switching element.SOLUTION: A semiconductor laser device 1A includes: a substrate 50 having a first surface; a first semiconductor laser element 10 mounted on the first surface; a switching element 20 which is mounted on the first surface and controls the current flowing through the first semiconductor laser element 10; and a first capacitor 30 mounted on the first surface. The first semiconductor laser element 10 is connected in series with the switching element 20, and the first capacitor 30 is connected in parallel with the first semiconductor laser element 10 and the switching element 20. When viewed from a first direction parallel to the first surface, the first semiconductor laser element 10 overlaps the switching element 20. When viewed from a second direction parallel to the first surface and orthogonal to the first direction, the first capacitor 30 overlaps at least one of the first semiconductor laser element 10 and the switching element 20.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a semiconductor laser device. [Background technology]

[0002] A known technique for three-dimensional distance measurement used in vehicles, etc., is to emit laser light toward a measurement object and measure the distance to the measurement object based on the light reflected by the measurement object. A system using LiDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging) has been proposed as a laser distance measurement device to which this technique is applied (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-128432

[0004] [overview] A semiconductor laser device used as a light source for LiDAR includes a laser diode and a transistor connected in series with the laser diode. The transistor is switched on and off to emit laser light with a pulse width of several tens of nanoseconds or less. When the pulse width is several tens of nanoseconds or less, the time rate of change of the current flowing through the laser diode increases, which can increase the back electromotive force caused by the inductance within the semiconductor laser device. This back electromotive force can then affect the gate voltage of the transistor. This problem is not limited to transistors; even when other switching elements are used, the back electromotive force caused by the inductance can affect the control voltage applied to the control electrode of the switching element.

[0005] An object of the present disclosure is to provide a semiconductor laser device that can reduce the influence of a back electromotive force caused by inductance on the control voltage of a switching element. A semiconductor laser device according to one aspect of the present disclosure includes a substrate having a first surface, a first semiconductor laser element mounted on the first surface, a switching element mounted on the first surface and controlling a current flowing through the first semiconductor laser element, and a first capacitor mounted on the first surface. The first semiconductor laser element is connected in series to the switching element, and the first capacitor is connected in parallel to the first semiconductor laser element and the switching element. When viewed from a first direction parallel to the first surface, the first semiconductor laser element overlaps with the switching element, and when viewed from a second direction parallel to the first surface and orthogonal to the first direction, the first capacitor overlaps with at least one of the first semiconductor laser element and the switching element. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a schematic circuit diagram of a laser system to which the semiconductor laser device of the first embodiment is applied. [Figure 2] FIG. 2 is a plan view showing the internal configuration of the semiconductor laser device of the first embodiment with the sealing member removed. [Figure 3] FIG. 3 is a rear view of the semiconductor laser device of the first embodiment. [Figure 4] FIG. 4 is a cross-sectional view taken along line 4-4 in FIG. [Figure 5] FIG. 5 is a cross-sectional view taken along line 5-5 in FIG. [Figure 6] FIG. 6 is a cross-sectional view taken along line 6-6 in FIG. [Figure 7] FIG. 7 is a cross-sectional view taken along line 7-7 in FIG. [Figure 8] FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. [Figure 9] FIG. 9 is a cross-sectional view showing a schematic cross-sectional structure of the semiconductor laser device of the first embodiment. [Figure 10] FIG. 10 is a schematic plan view of the semiconductor laser device of the first embodiment. [Figure 11] FIG. 11 is a schematic circuit diagram of a laser system to which a semiconductor laser device of the comparative example is applied. [Figure 12] FIG. 12 is a graph showing the transition of the current flowing through the semiconductor laser element and the voltage applied to the gate electrode of the switching element in the semiconductor laser device of the comparative example. [Figure 13] FIG. 13 is a graph showing the transition of the electromotive voltage of the parasitic inductance in the semiconductor laser device of the comparative example. [Figure 14] FIG. 14 is a schematic diagram for explaining a connection configuration when the semiconductor laser device of the first embodiment is used in a laser system. [Figure 15] FIG. 15 is a schematic circuit diagram of a laser system to which the semiconductor laser device of the first embodiment is applied. [Figure 16] FIG. 16 is a graph showing the transition of the current flowing through the semiconductor laser element and the voltage applied to the gate electrode of the switching element in the semiconductor laser device of the first embodiment. [Figure 17] FIG. 17 is a plan view showing the internal configuration of a modified example of the semiconductor laser device of the first embodiment, with the sealing member removed. [Figure 18] FIG. 18 is a rear view of the semiconductor laser device of FIG. [Figure 19] FIG. 19 is a plan view showing the internal configuration of a modified example of the semiconductor laser device of the first embodiment, with the sealing member removed. [Figure 20] FIG. 20 is a plan view showing the internal configuration of a modified example of the semiconductor laser device of the first embodiment, with the sealing member removed. [Figure 21] FIG. 21 is a cross-sectional view showing a schematic cross-sectional structure of the semiconductor laser element of the semiconductor laser device of FIG. [Figure 22] FIG. 22 is a rear view of a semiconductor laser device according to a modification of the semiconductor laser device of the first embodiment. [Figure 23]FIG. 23 is a plan view showing the internal configuration of a modified example of the semiconductor laser device of the first embodiment, with the sealing member removed. [Figure 24] FIG. 24 is a rear view of the semiconductor laser device of FIG. [Figure 25] FIG. 25 is a cross-sectional view taken along line 25-25 in FIG. [Figure 26] FIG. 26 is a plan view showing the internal configuration of the semiconductor laser device of the second embodiment with the sealing member removed. [Figure 27] FIG. 27 is a rear view of the semiconductor laser device of FIG. [Figure 28] FIG. 28 is a plan view showing the internal configuration of the semiconductor laser device of the third embodiment with the sealing member removed. [Figure 29] FIG. 29 is a rear view of the semiconductor laser device of FIG. [Figure 30] FIG. 30 is a plan view showing the internal configuration of a modified example of the semiconductor laser device of the third embodiment, with the sealing member removed. [Figure 31] FIG. 31 is a plan view showing the internal configuration of a modified example of the semiconductor laser device of the third embodiment, with the sealing member removed. [Figure 32] FIG. 32 is a plan view showing the internal configuration of a modified example of the semiconductor laser device of the third embodiment, with the sealing member removed. [Figure 33] FIG. 33 is a plan view showing the internal configuration of the semiconductor laser device of the fourth embodiment with the sealing member removed. [Figure 34] FIG. 34 is a rear view of the semiconductor laser device of FIG. [Figure 35] FIG. 35 is a plan view showing the internal configuration of a modified example of the semiconductor laser device of the fourth embodiment, with the sealing member removed. [Figure 36] FIG. 36 is a rear view of the semiconductor laser device of FIG. [Figure 37]FIG. 37 is a plan view showing the internal configuration of a modified example of the semiconductor laser device of the fourth embodiment, with the sealing member removed. [Figure 38] FIG. 38 is a plan view showing the internal configuration of a modified example of the semiconductor laser device of the fourth embodiment, with the sealing member removed. [Figure 39] FIG. 39 is a rear view of the semiconductor laser device of FIG. [Figure 40] FIG. 40 is a plan view showing the internal configuration of a modified example of the semiconductor laser device of the fourth embodiment, with the sealing member removed. [Figure 41] FIG. 41 is a plan view showing the internal configuration of a modified example of the semiconductor laser device of the fourth embodiment, with the sealing member removed. [Figure 42] FIG. 42 is a plan view showing the internal configuration of a modified example of the semiconductor laser device of the fourth embodiment, with the sealing member removed. [Figure 43] FIG. 43 is a plan view showing the internal configuration of a modified example of the semiconductor laser device of the fourth embodiment, with the sealing member removed. [Figure 44] FIG. 44 is a plan view showing the internal configuration of the semiconductor laser device of the fifth embodiment with the sealing member removed. [Figure 45] FIG. 45 is a rear view of the semiconductor laser device of FIG. [Figure 46] FIG. 46 is a schematic diagram for explaining a connection configuration when the semiconductor laser device of the fifth embodiment is used in a laser system.

[0007] [Detailed explanation] Hereinafter, embodiments of a semiconductor laser device will be described with reference to the drawings. The embodiments shown below are intended to exemplify configurations and methods for embodying the technical ideas, and are not intended to limit the materials, shapes, structures, arrangements, dimensions, etc. of the components to those described below. Various modifications can be made to the following embodiments.

[0008] [First embodiment] A semiconductor laser device according to a first embodiment will be described with reference to FIGS. (Circuit configuration of semiconductor laser device and laser system) As shown in FIG. 1, a semiconductor laser device 1A configured by the portion surrounded by a dashed line in FIG. 1 is used as a pulsed laser light source for LiDAR, which is an example of three-dimensional distance measurement. FIG. 1 shows a configuration in which the semiconductor laser device 1A is used in a laser system 100 as a LiDAR. The semiconductor laser device 1A includes a semiconductor laser element 10, a switching element 20, a capacitor 30, and a plurality of terminals 40. In FIG. 1, the semiconductor laser device 1A includes five terminals 40. The semiconductor laser device 1A may also be used in a laser system for two-dimensional distance measurement. The number of terminals 40 can be changed as desired.

[0009] The laser system 100 includes a power supply 110, a current-limiting resistor 120, a diode 130, and a driver circuit 140. The power supply 110 has a positive electrode 111 and a negative electrode 112 and supplies power to the semiconductor laser element 10. The current-limiting resistor 120 is provided between the positive electrode 111 of the power supply 110 and the semiconductor laser element 10 and limits the current flowing from the power supply 110 to the semiconductor laser element 10. The diode 130 has an anode electrode 131 and a cathode electrode 132 and is connected in anti-parallel to the semiconductor laser element 10 to prevent backflow to the semiconductor laser element 10. In the laser system 100 of FIG. 1, a Schottky barrier diode is used as the diode 130. The driver circuit 140 has an output electrode 141 and an input electrode 142 and outputs a control signal to the switching element 20 to control on / off of the switching element 20.

[0010] The semiconductor laser element 10 is a light source of the semiconductor laser device 1A, and is, for example, a pulse laser diode. The semiconductor laser element 10 is made of, for example, GaAs (gallium arsenide). The semiconductor laser element 10 includes an anode electrode 11 and a cathode electrode 12. The switching element 20 is an element for turning on and off current to the semiconductor laser element 10. The semiconductor laser element 10 has, for example, an oscillation wavelength of 905 nm, an optical output of 75 W or more, and a pulse width of several tens of nanoseconds or less. Preferably, the semiconductor laser element 10 has an optical output of 150 W or more and a pulse width of 10 ns or less. More preferably, the semiconductor laser element 10 has a pulse width of 5 ns or less.

[0011] The switching element 20 is a transistor made of, for example, Si (silicon), SiC (silicon carbide), or GaN (gallium nitride). When the switching element 20 is made of GaN or SiC, it is suitable for high-speed switching. In this embodiment, an N-type MOSFET (Metal-Oxide-Semiconductor Field-Effect-Transistor) made of Si is used as the switching element 20. The switching element 20 includes a drain electrode 21 which is an example of a first drive electrode, a source electrode 22 which is an example of a second drive electrode, and a gate electrode 23 which is an example of a control electrode.

[0012] The capacitor 30 constitutes a capacitor bank for temporarily storing charge to be used as a current to be passed through the semiconductor laser element 10. The capacitor 30 stores charge, for example, when the switching element 20 is in an OFF state, and discharges the charge to the semiconductor laser element 10 when the switching element 20 is in an ON state. The number of capacitors 30 may be one or more. For example, the capacitance and number of the capacitors 30 are set according to the output of the semiconductor laser element 10. The capacitor 30 has a first terminal 31 and a second terminal 32.

[0013] 1, the semiconductor laser element 10 and the switching element 20 are connected in series. Specifically, the cathode electrode 12 of the semiconductor laser element 10 and the drain electrode 21 of the switching element 20 are electrically connected. The anode electrode 11 of the semiconductor laser element 10 is electrically connected to a first power supply terminal 41. The source electrode 22 of the switching element 20 is electrically connected to a second power supply terminal 42. The anode electrode 131 of the diode 130 is electrically connected to a node N between the cathode electrode 12 of the semiconductor laser element 10 and the drain electrode 21 of the switching element 20.

[0014] The capacitor 30 is connected in parallel with the semiconductor laser element 10 and the switching element 20. Specifically, a first terminal 31 of the capacitor 30 is electrically connected to the source electrode 22 of the switching element 20, and a second terminal 32 of the capacitor 30 is electrically connected to the anode electrode 11 of the semiconductor laser element 10.

[0015] The multiple terminals 40 include a first power supply terminal 41, a second power supply terminal 42, a control terminal 43, a diode connection terminal 44, and a driver connection terminal 45. As shown in FIG. 1 , the first power supply terminal 41 is electrically connected to the positive electrode 111 of the power supply 110 and the cathode electrode 132 of the diode 130. The first power supply terminal 41 is also electrically connected to the anode electrode 11 of the semiconductor laser device 10 and the second terminal 32 of the capacitor 30. The second power supply terminal 42 is electrically connected to the negative electrode 112 of the power supply 110. The second power supply terminal 42 is also electrically connected to the source electrode 22 of the switching element 20 and the first terminal 31 of the capacitor 30. The control terminal 43 is connected to the output electrode 141 of the driver circuit 140. The diode connection terminal 44 is connected to the anode electrode 131 of the diode 130. The diode connection terminal 44 is also connected to a node N between the cathode electrode 12 of the semiconductor laser device 10 and the drain electrode 21 of the switching element 20. Therefore, the anode electrode 131 of the diode 130 and the cathode electrode 12 of the semiconductor laser device 10 are electrically connected via the diode connection terminal 44. The driver connection terminal 45 is electrically connected to an input electrode 142 of the driver circuit 140.

[0016] The laser system 100 configured as described above operates as follows: When the switching element 20 is turned off by a control signal from the driver circuit 140, the capacitor 30 is charged by the power supply 110. When the switching element 20 is turned on by a control signal from the driver circuit 140, the capacitor 30 is discharged, causing a current to flow through the semiconductor laser element 10. This causes the semiconductor laser element 10 to output pulsed laser light.

[0017] (Configuration of semiconductor laser device) The semiconductor laser device 1A is modularized. That is, the semiconductor laser device 1A has a configuration in which a semiconductor laser element 10, a switching element 20, and a capacitor 30 are housed in one package. The detailed configuration of such a semiconductor laser device 1A will be described below.

[0018] The semiconductor laser device 1A includes a support substrate 50 that supports the semiconductor laser element 10, the switching element 20, and the capacitor 30 and constitutes part of the package, and a sealing member 90 that seals the semiconductor laser element 10, the switching element 20, and the capacitor 30 and constitutes part of the package. In this embodiment, the package of the semiconductor laser device 1A is formed by the support substrate 50 and the sealing member 90. The semiconductor laser device 1A also has two capacitors 30A and 30B as the capacitor 30.

[0019] The support substrate 50 forms conductive paths for the semiconductor laser element 10, the switching element 20, and the capacitor 30 (30A, 30B), and supports the semiconductor laser element 10, the switching element 20, and the capacitor 30. The support substrate 50 has a base material 51 and a conductive portion 60.

[0020] The substrate 51 is made of an electrically insulating material. For example, the substrate 51 is made of epoxy resin or ceramics. In this embodiment, glass epoxy resin is used as the material constituting the substrate 51. The substrate 51 has a substrate main surface 51a, a substrate back surface 51b, a first substrate side surface 51c, a second substrate side surface 51d, a third substrate side surface 51e, and a fourth substrate side surface 51f. In the following description, the thickness direction of the substrate 51 is referred to as the "thickness direction Z," and directions perpendicular to the thickness direction Z and perpendicular to each other are referred to as the "horizontal direction X" and the "vertical direction Y." The vertical direction Y corresponds to the first direction, and the horizontal direction X corresponds to the second direction.

[0021] The substrate main surface 51a and the substrate back surface 51b are surfaces facing opposite each other in the thickness direction Z. The first substrate side surface 51c, the second substrate side surface 51d, the third substrate side surface 51e, and the fourth substrate side surface 51f are surfaces provided between the substrate main surface 51a and the substrate back surface 51b in the thickness direction Z and extending in a direction intersecting the substrate main surface 51a and the substrate back surface 51b. The first substrate side surface 51c and the second substrate side surface 51d face opposite each other, and the third substrate side surface 51e and the fourth substrate side surface 51f face opposite each other. In this embodiment, the first substrate side surface 51c and the second substrate side surface 51d face opposite each other in the vertical direction Y and extend along the horizontal direction X. The third substrate side surface 51e and the fourth substrate side surface 51f face opposite each other in the horizontal direction X and extend along the vertical direction Y.

[0022] The shape of the substrate 51 in a plan view of the semiconductor laser device 1A (hereinafter simply referred to as "plan view") is rectangular. In this embodiment, the shape of the substrate 51 in a plan view is rectangular in which the first substrate side surface 51c and the second substrate side surface 51d are in the long side direction and the third substrate side surface 51e and the fourth substrate side surface 51f are in the short side direction.

[0023] The conductive portion 60 is provided on the substrate 51 and forms a conductive path to the semiconductor laser element 10, the switching element 20, and the capacitor 30. The material of the conductive portion 60 is not particularly limited, but metals such as Cu (copper), Ni (nickel), Ti (titanium), and Au (gold) are used. The method for forming the conductive portion 60 is not particularly limited, but it is formed by plating, for example. The conductive portion 60 has a main surface side conductive portion 60A as a driving conductive portion, a back surface side conductive portion 60B as a terminal conductive portion, and a connecting portion 60C.

[0024] The main surface side conductive portion 60A is formed on the substrate main surface 51a of the substrate 51. The main surface side conductive portion 60A has a pair of first drive conductive portions 61A, 61B, a second drive conductive portion 62, a third drive conductive portion 63, a pair of fourth drive conductive portions 64A, 64B, and a control conductive portion 65.

[0025] The pair of first driving conductive parts 61A, 61B are arranged at both ends of the substrate main surface 51a in the horizontal direction X and at the center in the vertical direction Y. In a plan view, the first driving conductive part 61A is arranged in a portion of the substrate main surface 51a closer to the third substrate side surface 51e and spaced apart in the horizontal direction X from the third substrate side surface 51e. In a plan view, the first driving conductive part 61B is arranged in a portion of the substrate main surface 51a closer to the fourth substrate side surface 51f and spaced apart in the horizontal direction X from the fourth substrate side surface 51f. In a plan view, each of the first driving conductive parts 61A, 61B has a rectangular shape with its longer side extending in the vertical direction Y and its shorter side extending in the horizontal direction X. In this embodiment, the first driving conductive parts 61A, 61B have the same shape in a plan view. Note that the shapes of the first driving conductive parts 61A, 61B in a plan view can be arbitrarily changed. For example, the shape of the first driving conductive portion 61A in a plan view may be different from the shape of the first driving conductive portion 61B in a plan view.

[0026] The third drive conductive portion 63 is disposed on the substrate main surface 51a in a portion between the pair of first drive conductive portions 61A, 61B in the horizontal direction X. The third drive conductive portion 63 has a convex shape in a plan view. The third drive conductive portion 63 can be divided into a switching element mounting portion 63a, which is a portion sandwiched between the pair of first drive conductive portions 61A, 61B, and a semiconductor laser element mounting portion 63b, which protrudes in the vertical direction Y from the switching element mounting portion 63a.

[0027] The switching element mounting portion 63a is disposed on a portion of the substrate main surface 51a closer to the second substrate side surface 51d in the vertical direction Y. The switching element mounting portion 63a is disposed at a distance from the pair of first drive conductive portions 61A, 61B in the horizontal direction X. The shape of the switching element mounting portion 63a in a plan view is square. The size of the switching element mounting portion 63a in the horizontal direction X is larger than the size of each of the pair of first drive conductive portions 61A, 61B in the horizontal direction X. The size of the switching element mounting portion 63a in the vertical direction Y is not particularly limited, but in this embodiment, it is equal to the size of each of the pair of first drive conductive portions 61A, 61B in the vertical direction Y. Here, if the difference between the vertical size Y of the switching element mounting portion 63a and the vertical size Y of the pair of first drive conductive portions 61A, 61B is within 5% of the vertical size Y of the pair of first drive conductive portions 61A, 61B, it can be said that the vertical size Y of the switching element mounting portion 63a is equal to the vertical size Y of the pair of first drive conductive portions 61A, 61B.

[0028] The switching element 20 is mounted on the switching element mounting portion 63a. As shown in FIGS. 2 and 4, the switching element 20 is formed in a flat plate shape. The switching element 20 has an element body 24 made of a semiconductor material such as Si or SiC. The element body 24 has an element main surface 24a and an element back surface 24b facing opposite sides in the thickness direction Z. The element main surface 24a faces the same side as the laser element main surface 10a of the semiconductor laser element 10. The element back surface 24b faces the same side as the laser element back surface 10b.

[0029] A source electrode 22 and a gate electrode 23 are formed on the element principal surface 24a. The source electrode 22 is formed over most of the element principal surface 24a. The source electrode 22 has a concave shape in plan view that opens toward the second substrate side surface 51d. In this embodiment, the source electrode 22 has a recess 22a that is recessed in the vertical direction Y in plan view. The recess 22a is formed at an end of the source electrode 22 closer to the second substrate side surface 51d and at the center in the horizontal direction X. The gate electrode 23 is formed in the recess 22a.

[0030] A drain electrode 21 is formed on the back surface 24b of the element. The drain electrode 21 is formed, for example, over the entire back surface 24b of the element. As described above, the switching element 20 of this embodiment is a transistor with a so-called vertical structure.

[0031] The semiconductor laser element mounting portion 63b is disposed at an end of the switching element mounting portion 63a closer to the first substrate side surface 51c in the vertical direction Y and at the center of the switching element mounting portion 63a in the horizontal direction X. In plan view, the semiconductor laser element mounting portion 63b has a rectangular shape with its longer side in the vertical direction Y and its shorter side in the horizontal direction X. The size of the semiconductor laser element mounting portion 63b in the horizontal direction X is smaller than the size of the switching element mounting portion 63a in the horizontal direction X. The size of the semiconductor laser element mounting portion 63b in the horizontal direction X is also smaller than the size of the pair of first drive conductors 61A, 61B in the horizontal direction X. The size of the semiconductor laser element mounting portion 63b in the vertical direction Y is also smaller than the size of the pair of first drive conductors 61A, 61B in the vertical direction Y.

[0032] A semiconductor laser element 10 is mounted on the semiconductor laser element mounting portion 63b. As shown in FIGS. 2 and 4, the semiconductor laser element 10 is formed in a flat plate shape. In plan view, the semiconductor laser element 10 has a rectangular shape with its longer sides aligned in the vertical direction Y and its shorter sides aligned in the horizontal direction X. The semiconductor laser element 10 has a laser element main surface 10a and a laser element back surface 10b facing opposite sides in the thickness direction Z. In this embodiment, an anode electrode 11 is formed on the laser element main surface 10a, and a cathode electrode 12 is formed on the laser element back surface 10b.

[0033] The shape of the switching element mounting portion 63a in plan view can be changed arbitrarily. For example, the shape of the switching element mounting portion 63a in plan view may be rectangular with one of the horizontal direction X and the vertical direction Y as its long side direction and the other of the horizontal direction X and the vertical direction Y as its short side direction. The shape of the semiconductor laser element mounting portion 63b in plan view can be changed arbitrarily. For example, the shape of the semiconductor laser element mounting portion 63b in plan view may be square, or rectangular with the horizontal direction X as its long side direction and the vertical direction Y as its short side direction.

[0034] The pair of fourth drive conductive parts 64A, 64B are each arranged at an end of the substrate main surface 51a closer to the first substrate side surface 51c in the vertical direction Y. The pair of fourth drive conductive parts 64A, 64B are arranged spaced apart in the vertical direction Y from the first substrate side surface 51c. The fourth drive conductive part 64A is arranged at an end of the substrate main surface 51a closer to the third substrate side surface 51e. The fourth drive conductive part 64A is arranged spaced apart from the third substrate side surface 51e in the horizontal direction X. The fourth drive conductive part 64B is arranged at an end of the substrate main surface 51a closer to the fourth substrate side surface 51f. The fourth drive conductive part 64B is arranged spaced apart from the fourth substrate side surface 51f in the horizontal direction X. The pair of fourth drive conductive parts 64A, 64B are arranged on both sides of the semiconductor laser element mounting part 63b in the horizontal direction X and spaced apart from the semiconductor laser element mounting part 63b in the horizontal direction X. When viewed from the vertical direction Y, the fourth drive conductive portion 64A is arranged to overlap the first drive conductive portion 61A. When viewed from the vertical direction Y, an end portion of the fourth drive conductive portion 64A closer to the semiconductor laser element mounting portion 63b is arranged to overlap an end portion of the switching element mounting portion 63a closer to the third substrate side surface 51e. When viewed from the vertical direction Y, the fourth drive conductive portion 64B is arranged to overlap the first drive conductive portion 61B. When viewed from the vertical direction Y, an end portion of the fourth drive conductive portion 64B closer to the semiconductor laser element mounting portion 63b is arranged to overlap an end portion of the switching element mounting portion 63a closer to the fourth substrate side surface 51f. When viewed from the horizontal direction X, the pair of fourth drive conductive portions 64A, 64B are arranged to overlap the semiconductor laser element mounting portion 63b.

[0035] The pair of fourth drive conductors 64A, 64B have a rectangular shape in plan view with the longer side in the horizontal direction X and the shorter side in the vertical direction Y. The size in the horizontal direction X of the pair of fourth drive conductors 64A, 64B is larger than the size in the horizontal direction X of the pair of first drive conductors 61A, 61B. The size in the vertical direction Y of the pair of fourth drive conductors 64A, 64B is smaller than the size in the vertical direction Y of the pair of first drive conductors 61A, 61B. The size in the vertical direction Y of the pair of fourth drive conductors 64A, 64B is smaller than the size in the vertical direction Y of the semiconductor laser element mounting portion 63b. In this embodiment, the fourth drive conductors 64A, 64B have the same shape in plan view. The shapes of the fourth drive conductors 64A, 64B in plan view can be changed as desired. For example, the shape of the fourth drive conductive portion 64A in a plan view may be different from the shape of the fourth drive conductive portion 64B in a plan view.

[0036] The second driving conductive portion 62 and the control conductive portion 65 are each arranged at an end of the substrate main surface 51a closer to the second substrate side surface 51d in the vertical direction Y. The second driving conductive portion 62 and the control conductive portion 65 are arranged along the horizontal direction X while being spaced apart from each other in the horizontal direction X. The second driving conductive portion 62 and the control conductive portion 65 are each arranged spaced apart from the second substrate side surface 51d in the vertical direction Y. The second driving conductive portion 62 is arranged at an end of the substrate main surface 51a closer to the fourth substrate side surface 51f in the horizontal direction X. The second driving conductive portion 62 is arranged spaced apart from the fourth substrate side surface 51f in the horizontal direction X. The control conductive portion 65 is arranged at an end of the substrate main surface 51a closer to the third substrate side surface 51e in the horizontal direction X. The control conductive portion 65 is arranged spaced apart from the third substrate side surface 51e in the horizontal direction X.

[0037] The second drive conductive portion 62 has a rectangular shape in plan view, with its longer side extending in the horizontal direction X and its shorter side extending in the vertical direction Y. The size of the second drive conductive portion 62 in the vertical direction Y is smaller than the size of the pair of first drive conductive portions 61A, 61B and the switching element mounting portion 63a in the vertical direction Y. The size of the second drive conductive portion 62 in the horizontal direction X is larger than the size of the pair of first drive conductive portions 61A, 61B in the horizontal direction X. The size of the second drive conductive portion 62 in the horizontal direction X is larger than the size of the pair of fourth drive conductive portions 64A, 64B in the horizontal direction X. The shape of the second drive conductive portion 62 in plan view can be arbitrarily changed. For example, the shape of the second drive conductive portion 62 in plan view may be a square or a rectangle with its longer side extending in the vertical direction Y and its shorter side extending in the horizontal direction X.

[0038] The shape of the control conductive portion 65 in plan view is a rectangle with its longer side in the horizontal direction X and its shorter side in the vertical direction Y. The size of the control conductive portion 65 in the vertical direction Y is smaller than the size of the pair of first drive conductive portions 61A, 61B in the vertical direction Y. The size of the control conductive portion 65 in the horizontal direction X is larger than the size of the pair of first drive conductive portions 61A, 61B in the horizontal direction X. The size of the control conductive portion 65 in the horizontal direction X is larger than the size of the pair of fourth drive conductive portions 64A, 64B in the horizontal direction X. The shape of the control conductive portion 65 in plan view can be changed as desired. For example, the shape of the control conductive portion 65 in plan view may be a square or a rectangle with its longer side in the vertical direction Y and its shorter side in the horizontal direction X.

[0039] When viewed from the vertical direction Y, the second drive conductive portion 62 is arranged to overlap the first drive conductive portion 61B and the fourth drive conductive portion 64B and the end portion of the switching element mounting portion 63a that is closer to the fourth substrate side surface 51f. When viewed from the vertical direction Y, the control conductive portion 65 is arranged to overlap the first drive conductive portion 61A and the fourth drive conductive portion 64A and the end portion of the switching element mounting portion 63a that is closer to the third substrate side surface 51e.

[0040] 3, the back-side conductive portion 60B is formed on the substrate back surface 51b of the substrate 51. The back-side conductive portion 60B has a pair of first terminal conductive portions 66A, 66B, a second terminal conductive portion 67, a third terminal conductive portion 68, a pair of fourth terminal conductive portions 69A, 69B, and a control terminal conductive portion 70. As such, in this embodiment, the semiconductor laser device 1A is a surface-mounted package.

[0041] The back-surface-side conductive portion 60B is used as a terminal when the semiconductor laser device 1A is mounted on a wiring board (not shown) or the like, i.e., as the plurality of terminals 40 in Fig. 1. As shown in Fig. 1 and Fig. 3, the pair of first-terminal conductive portions 66A, 66B constitute the second power supply terminal 42, the second-terminal conductive portion 67 constitutes the driver connection terminal 45, the third-terminal conductive portion 68 constitutes the diode connection terminal 44, and the fourth-terminal conductive portions 69A, 69B constitute the first power supply terminal 41.

[0042] 3, the pair of first terminal conductive portions 66A, 66B are arranged at both ends of the substrate back surface 51b in the horizontal direction X and at the center in the vertical direction Y. In plan view, the first terminal conductive portion 66A is arranged in a portion of the substrate back surface 51b closer to the third substrate side surface 51e and spaced apart in the horizontal direction X from the third substrate side surface 51e. In plan view, the first terminal conductive portion 66B is arranged in a portion of the substrate back surface 51b closer to the fourth substrate side surface 51f and spaced apart in the horizontal direction X from the fourth substrate side surface 51f. When viewed in the thickness direction Z, the first terminal conductive portion 66A is arranged to overlap the first driving conductive portion 61A.

[0043] The shape of each of the first terminal conductive portions 66A, 66B in a plan view is a rectangle with the longer side in the vertical direction Y and the shorter side in the horizontal direction X. The size of the first terminal conductive portions 66A, 66B in the horizontal direction X is smaller than the size of the first drive conductive portions 61A, 61B in the horizontal direction X. The size of the first terminal conductive portions 66A, 66B in the vertical direction Y is smaller than the size of the first drive conductive portions 61A, 61B in the vertical direction Y. In this embodiment, the shapes of the first terminal conductive portions 66A, 66B in a plan view are the same. Note that the shapes of the first terminal conductive portions 66A, 66B in a plan view can be arbitrarily changed. For example, the shape of the first terminal conductive portion 66A in a plan view may be different from the shape of the first terminal conductive portion 66B in a plan view.

[0044] The third terminal conductive portion 68 is disposed on the substrate back surface 51b in a portion between the pair of first terminal conductive portions 66A, 66B in the horizontal direction X. The third terminal conductive portion 68 is disposed on the substrate back surface 51b closer to the first substrate side surface 51c in the vertical direction Y. When viewed from the thickness direction Z, the third terminal conductive portion 68 is disposed so as to overlap the third driving conductive portion 63.

[0045] The third terminal conductive portion 68 has a rectangular shape in plan view with its longer sides aligned in the vertical direction Y and its shorter sides aligned in the horizontal direction X. For convenience, the third terminal conductive portion 68 is divided by a boundary line Lb in the thickness direction Z into a first terminal portion 68a overlapping the switching element mounting portion 63a of the third drive conductive portion 63 and a second terminal portion 68b overlapping the semiconductor laser element mounting portion 63b.

[0046] The size in the horizontal direction X of the first terminal portion 68a is smaller than the size in the horizontal direction X of the switching element mounting portion 63a. The size in the vertical direction Y of the first terminal portion 68a is smaller than the size in the vertical direction Y of the switching element mounting portion 63a. The size in the horizontal direction X of the second terminal portion 68b is larger than the size in the horizontal direction X of the semiconductor laser element mounting portion 63b. The size in the vertical direction Y of the second terminal portion 68b is equal to the size in the vertical direction Y of the semiconductor laser element mounting portion 63b. As shown in FIG. 6, the second terminal portion 68b is formed to overlap the fourth driving conductors 64A, 64B in the thickness direction Z.

[0047] As shown in FIG. 3 , the pair of fourth terminal conductive portions 69A, 69B are each arranged at an end of the substrate back surface 51b closer to the first substrate side surface 51c in the vertical direction Y. The pair of fourth terminal conductive portions 69A, 69B are arranged spaced apart from the first substrate side surface 51c in the vertical direction Y. The fourth terminal conductive portion 69A is arranged at an end of the substrate back surface 51b closer to the third substrate side surface 51e. The fourth terminal conductive portion 69A is arranged spaced apart from the third substrate side surface 51e in the horizontal direction X. The fourth terminal conductive portion 69B is arranged at an end of the substrate back surface 51b closer to the fourth substrate side surface 51f. The fourth terminal conductive portion 69B is arranged spaced apart from the fourth substrate side surface 51f in the horizontal direction X. The pair of fourth terminal conductive portions 69A, 69B are arranged on both sides of the second terminal portion 68b in the horizontal direction X and spaced apart from the second terminal portion 68b in the horizontal direction X. When viewed from the vertical direction Y, the fourth terminal conductive portion 69A is arranged to overlap with the first terminal conductive portion 66A. When viewed from the vertical direction Y, the fourth terminal conductive portion 69B is arranged to overlap with the first terminal conductive portion 66B. When viewed from the horizontal direction X, the pair of fourth terminal conductive portions 69A, 69B are arranged to overlap with the second terminal portion 68b. When viewed from the thickness direction Z, the fourth terminal conductive portion 69A is arranged to overlap with the fourth drive conductive portion 64A, and the fourth terminal conductive portion 69B is arranged to overlap with the fourth drive conductive portion 64B.

[0048] The pair of fourth terminal conductive portions 69A, 69B have a rectangular shape in plan view with the longer side in the horizontal direction X and the shorter side in the vertical direction Y. The size in the horizontal direction X of the pair of fourth terminal conductive portions 69A, 69B is larger than the size in the horizontal direction X of the pair of first terminal conductive portions 66A, 66B. The size in the horizontal direction X of the pair of fourth terminal conductive portions 69A, 69B is smaller than the size in the horizontal direction X of the pair of fourth drive conductive portions 64A, 64B. The size in the vertical direction Y of the pair of fourth terminal conductive portions 69A, 69B is smaller than the size in the vertical direction Y of the pair of first terminal conductive portions 66A, 66B. The size in the vertical direction Y of the pair of fourth terminal conductive portions 69A, 69B is equal to the size in the vertical direction Y of the pair of fourth drive conductive portions 64A, 64B. Here, if the difference between the size in the vertical direction Y of the pair of fourth terminal conductive portions 69A, 69B and the size in the vertical direction Y of the pair of fourth drive conductive portions 64A, 64B is, for example, within 5% of the size of the pair of fourth drive conductive portions 64A, 64B, it can be said that the size in the vertical direction Y of the pair of fourth terminal conductive portions 69A, 69B is equal to the size in the vertical direction Y of the pair of fourth drive conductive portions 64A, 64B. In this embodiment, the shapes of the fourth terminal conductive portions 69A, 69B in a plan view are the same. Note that the shapes of the fourth terminal conductive portions 69A, 69B in a plan view can be arbitrarily changed. For example, the shape of the fourth terminal conductive portion 69A in a plan view may be different from the shape of the fourth terminal conductive portion 69B in a plan view.

[0049] The second terminal conductive portion 67 and the control terminal conductive portion 70 are each arranged at an end of the substrate back surface 51b closer to the second substrate side surface 51d in the vertical direction Y. The second terminal conductive portion 67 and the control terminal conductive portion 70 are arranged along the horizontal direction X while being spaced apart from each other in the horizontal direction X. The second terminal conductive portion 67 and the control terminal conductive portion 70 are each arranged spaced apart from the second substrate side surface 51d in the vertical direction Y.

[0050] The second terminal conductive portion 67 is disposed at an end of the substrate back surface 51b closer to the fourth substrate side surface 51f in the horizontal direction X. The second terminal conductive portion 67 is disposed spaced apart from the fourth substrate side surface 51f in the horizontal direction X. When viewed from the vertical direction Y, the second terminal conductive portion 67 is disposed so as to overlap the first terminal conductive portion 66B and the fourth terminal conductive portion 69B, and the end of the third terminal conductive portion 68 closer to the fourth substrate side surface 51f. When viewed from the thickness direction Z, the second terminal conductive portion 67 is disposed so as to overlap the second driving conductive portion 62 shown in FIG. 2.

[0051] The shape of the second terminal conductive portion 67 in plan view is rectangular with its longer side extending in the horizontal direction X and its shorter side extending in the vertical direction Y. The size of the second drive conductive portion 62 in the vertical direction Y is smaller than the size of the pair of first terminal conductive portions 66A, 66B and the pair of third terminal conductive portion 68 in the vertical direction Y. The size of the second terminal conductive portion 67 in the horizontal direction X is larger than the size of the pair of first terminal conductive portions 66A, 66B in the horizontal direction X. The size of the second terminal conductive portion 67 in the horizontal direction X is larger than the size of the pair of fourth terminal conductive portions 69A, 69B in the horizontal direction X. The shape of the second drive conductive portion 62 in plan view can be arbitrarily changed. For example, the shape of the second drive conductive portion 62 in plan view may be square or rectangular with its longer side extending in the vertical direction Y and its shorter side extending in the horizontal direction X.

[0052] The control terminal conductive portion 70 is arranged at an end of the substrate back surface 51b closer to the third substrate side surface 51e in the horizontal direction X. The control terminal conductive portion 70 is arranged spaced apart from the third substrate side surface 51e in the horizontal direction X. When viewed from the vertical direction Y, the control terminal conductive portion 70 is arranged to overlap the first terminal conductive portion 66A and the fourth terminal conductive portion 69A, and the end of the third terminal conductive portion 68 closer to the third substrate side surface 51e. When viewed from the thickness direction Z, the control terminal conductive portion 70 is arranged to overlap the control conductive portion 65.

[0053] The shape of the control terminal conductive portion 70 in plan view is a rectangle with its longer side in the horizontal direction X and its shorter side in the vertical direction Y. The size of the control terminal conductive portion 70 in the vertical direction Y is smaller than the size of the pair of first terminal conductive portions 66A, 66B in the vertical direction Y. The size of the control terminal conductive portion 70 in the horizontal direction X is larger than the size of the pair of first terminal conductive portions 66A, 66B in the horizontal direction X. The size of the control terminal conductive portion 70 in the horizontal direction X is larger than the size of the pair of fourth terminal conductive portions 69A, 69B in the horizontal direction X. The shape of the control terminal conductive portion 70 in plan view can be changed as desired. For example, the shape of the control terminal conductive portion 70 in plan view may be a square or a rectangle with its longer side in the vertical direction Y and its shorter side in the horizontal direction X.

[0054] As can be seen from FIGS. 2 and 3 , the gap Gs1 in the vertical direction Y between the first drive conductive portion 61A and the fourth drive conductive portion 64A and the gap Gs1 in the vertical direction Y between the first drive conductive portion 61B and the fourth drive conductive portion 64B are smaller than the gap Gr1 in the vertical direction Y between the first terminal conductive portion 66A and the fourth terminal conductive portion 69A and the gap Gr1 in the vertical direction Y between the first terminal conductive portion 66B and the fourth terminal conductive portion 69B. In other words, the gap Gr1 is larger than the gap Gs1. Furthermore, the gap Gs2 in the horizontal direction X between the first drive conductive portions 61A, 61B and the third drive conductive portion 63 is smaller than the gap Gr2 in the horizontal direction X between the first terminal conductive portions 66A, 66B and the third terminal conductive portion 68. In other words, the gap Gr2 is larger than the gap Gs2. Furthermore, a gap Gs3 in the vertical direction Y between the switching element mounting portion 63a of the first drive conductive portions 61A, 61B and the third drive conductive portion 63 and the second drive conductive portion 62 is smaller than a gap Gr3 in the vertical direction Y between the first terminal portion 68a of the first terminal conductive portion 66A and the third terminal conductive portion 68 and the second terminal conductive portion 67. In other words, the gap Gr3 is larger than the gap Gs3. A gap Gs4 in the horizontal direction X between the fourth drive conductive portions 64A, 64B and the semiconductor laser element mounting portion 63b of the third drive conductive portion 63 is smaller than a gap Gr4 in the horizontal direction X between the fourth terminal conductive portions 69A, 69B and the second terminal portion 68b of the third terminal conductive portion 68. In other words, the gap Gr4 is larger than the gap Gs4. A gap Gs5 in the vertical direction Y between the switching element mounting portions 63a of the first drive conductive portion 61B and the third drive conductive portion 63 and the control conductive portion 65 is smaller than a gap Gr5 in the vertical direction Y between the first terminal portion 68a of the first terminal conductive portion 66B and the third terminal conductive portion 68 and the control terminal conductive portion 70. In other words, the gap Gr5 is larger than the gap Gs5. Furthermore, a gap Gs6 in the horizontal direction X between the second drive conductive portion 62 and the control conductive portion 65 is equal to the gap Gr6 in the horizontal direction X between the second terminal conductive portion 67 and the control terminal conductive portion 70. Here, if the difference between the gap Gs6 and the gap Gr6 is, for example, within 5% of the gap Gs6, it can be said that the gap Gs6 is equal to the gap Gr6. Note that the gap Gr6 may be larger than the gap Gs6.

[0055] As shown in FIGS. 2 to 5, 7, and 8, a plurality of connecting portions 60C are provided, connecting the main surface-side conductive portion 60A and the back surface-side conductive portion 60B. Each connecting portion 60C has the same structure and is composed of a through hole 71 and a conductor portion 72 embedded in the through hole 71. The through hole 71 is composed of a metal film 71a formed over the entire inner circumferential surface of the through hole 52 penetrating the substrate 51 in the thickness direction Z. An end of the metal film 71a closer to the substrate main surface 51a of the substrate 51 is connected to the main surface-side conductive portion 60A, and an end of the metal film 71a closer to the substrate back surface 51b of the substrate 51 is connected to the back surface-side conductive portion 60B. In this embodiment, the material constituting the metal film 71a is the same as the material constituting the main surface-side conductive portion 60A and the back surface-side conductive portion 60B. The material constituting the conductor portion 72 is, for example, a metal material, and in this embodiment, Cu (copper) is used.

[0056] 3, the communication section 60C has a plurality of first drive communication sections 73A, 73B, a plurality of second drive communication sections 74, a plurality of third drive communication sections 75, a plurality of fourth drive communication sections 76A, 76B, and a plurality of control communication sections 77. In this embodiment, the outer diameter and inner diameter of the through holes 71 (see, for example, FIG. 4) that constitute the plurality of first drive communication sections 73, the plurality of second drive communication sections 74, the plurality of third drive communication sections 75, the plurality of fourth drive communication sections 76, and the plurality of control communication sections 77 are equal to each other.

[0057] 2 to 4, the plurality of third drive connecting portions 75 connect the third drive conductive portion 63 and the third terminal conductive portion 68. The plurality of third drive connecting portions 75 include a plurality of (nine in this embodiment) switching element side connecting portions 75a, one semiconductor laser element side connecting portion 75b, and one intermediate connecting portion 75c. Note that the respective numbers of the switching element side connecting portions 75a, semiconductor laser element side connecting portions 75b, and intermediate connecting portions 75c are not limited to the above numbers and can be changed as desired.

[0058] The multiple switching element side connecting portions 75a are provided on the switching element mounting portion 63a of the third driving conductive portion 63. Eight of the nine switching element side connecting portions 75a are provided at positions overlapping with the source electrodes 22 of the switching elements 20 when viewed from the thickness direction Z. The remaining switching element side connecting portion 75a is provided at a position overlapping with the gate electrode 23 of the switching element 20 when viewed from the thickness direction Z. The nine switching element side connecting portions 75a are provided at positions overlapping with the drain electrodes 21 of the switching elements 20 when viewed from the thickness direction Z.

[0059] The semiconductor laser element side connecting portion 75b is provided on the semiconductor laser element mounting portion 63b of the third drive conductor 63. When viewed from the thickness direction Z, the semiconductor laser element side connecting portion 75b is provided at a position overlapping with the semiconductor laser element 10.

[0060] The intermediate connecting portion 75c is provided so as to straddle the boundary (boundary line Lb in FIGS. 2 and 3) between the switching element mounting portion 63a and the semiconductor laser element mounting portion 63b of the third driving conductive portion 63. That is, the intermediate connecting portion 75c is located between the semiconductor laser element side connecting portion 75b and the switching element side connecting portion 75a in the vertical direction Y. In other words, the intermediate connecting portion 75c is located between the semiconductor laser element 10 and the switching element 20 in the vertical direction Y.

[0061] 2, 3, and 5, a plurality of (two in this embodiment) first drive connecting portions 73A connect the first drive conductive portion 61A and the first terminal conductive portion 66A. The plurality of first drive connecting portions 73A are arranged at intervals in the vertical direction Y. Each first drive connecting portion 73A is disposed closer to the third substrate side surface 51e of the first drive conductive portion 61A and the first terminal conductive portion 66A in the horizontal direction X. Each first drive connecting portion 73A is disposed closer to the second drive conductive portion 62 (second terminal conductive portion 67) than the capacitor 30A in the vertical direction Y.

[0062] A plurality of (two in this embodiment) first drive connecting portions 73B connect the first drive conductive portion 61B and the first terminal conductive portion 66B. The plurality of first drive connecting portions 73B are arranged at intervals in the vertical direction Y so as to align with the plurality of first drive connecting portions 73A in the vertical direction Y. Each first drive connecting portion 73B is arranged closer to the fourth substrate side surface 51f of the first drive conductive portion 61B and the first terminal conductive portion 66B in the horizontal direction X. Each first drive connecting portion 73B is arranged closer to the control conductive portion 65 (control terminal conductive portion 70) side than the capacitor 30B in the vertical direction Y. The number of first drive connecting portions 73A, 73B is not limited to the above number and can be changed as desired.

[0063] 2, 3, and 6, the fourth drive connecting portion 76A connects the fourth drive conductive portion 64A and the fourth drive connecting portion 76A. When viewed from the vertical direction Y, the fourth drive connecting portion 76A is provided at a position overlapping the capacitor 30A. In the vertical direction Y, the fourth drive connecting portion 76A is located closer to the first substrate side surface 51c than the capacitor 30A of the fourth drive conductive portion 64A.

[0064] The fourth drive connecting portion 76B connects the fourth drive conductive portion 64B and the fourth drive connecting portion 76B. When viewed from the vertical direction Y, the fourth drive connecting portion 76A is provided at a position overlapping the capacitor 30B. The fourth drive connecting portion 76B is located on the fourth drive conductive portion 64B closer to the first substrate side surface 51c than the capacitor 30B in the vertical direction Y. Note that a plurality of each of the fourth drive connecting portions 76A and 76B may be provided.

[0065] As shown in FIGS. 2, 3, and 8, the plurality of (three in this embodiment) second drive connecting portions 74 each connect a second drive conductive portion 62 and a second terminal conductive portion 67. The plurality of second drive connecting portions 74 are arranged at intervals in the horizontal direction X. A distance Dx2 in the horizontal direction X between the second drive connecting portion 74 closest to the third substrate side surface 51e among the three second drive connecting portions 74 and the edge of the second drive conductive portion 62 closest to the third substrate side surface 51e is greater than a distance Dx1 in the horizontal direction X between the second drive connecting portion 74 closest to the fourth substrate side surface 51f among the three second drive connecting portions 74 and the edge of the second drive conductive portion 62 closest to the fourth substrate side surface 51f. The number of second drive connecting portions 74 is not limited to the above number and can be changed as desired.

[0066] Each of the multiple (three in this embodiment) control connecting portions 77 connects the control conductive portion 65 and the control terminal conductive portion 70. The multiple control connecting portions 77 are arranged at intervals in the horizontal direction X. A distance Dx4 in the horizontal direction X between the control connecting portion 77 closest to the fourth substrate side surface 51f of the three control connecting portions 77 and the edge of the control conductive portion 65 closest to the fourth substrate side surface 51f is greater than a distance Dx3 in the horizontal direction X between the control connecting portion 77 closest to the third substrate side surface 51e of the three control connecting portions 77 and the edge of the control conductive portion 65 closest to the third substrate side surface 51e. The number of control connecting portions 77 is not limited to the above number and can be changed as desired.

[0067] Next, the connection structure between the semiconductor laser element 10, the switching element 20, the capacitors 30A and 30B, and the conductive section 60 will be described. The capacitor 30A is connected to the first drive conductive portion 61A and the fourth drive conductive portion 64A. The capacitor 30A is arranged to span the gap between the first drive conductive portion 61A and the fourth drive conductive portion 64A in the vertical direction Y. In this embodiment, the capacitor 30A is arranged such that the first terminal 31 and the second terminal 32 are aligned along the vertical direction Y. The first terminal 31 of the capacitor 30A is joined to the first drive conductive portion 61A with a conductive bonding material such as Ag paste or solder. The second terminal 32 of the capacitor 30A is joined to the fourth drive conductive portion 64A with a conductive bonding material. The second terminal 32 is arranged in a portion of the fourth drive conductive portion 64A closer to the first drive conductive portion 61A than the fourth drive connection portion 76A in the vertical direction Y.

[0068] The capacitor 30B is connected to the first drive conductive portion 61B and the fourth drive conductive portion 64B. The capacitor 30B is arranged to straddle the gap between the first drive conductive portion 61B and the fourth drive conductive portion 64B in the vertical direction Y. In this embodiment, the capacitor 30B is arranged such that the first terminal 31 and the second terminal 32 are aligned along the vertical direction Y. The first terminal 31 of the capacitor 30B is joined to the first drive conductive portion 61B with a conductive bonding material. The second terminal 32 of the capacitor 30B is joined to the fourth drive conductive portion 64B with a conductive bonding material. The second terminal 32 is arranged in a portion of the fourth drive conductive portion 64B closer to the first drive conductive portion 61B than the fourth drive connection portion 76B in the vertical direction Y.

[0069] As shown in FIGS. 2 and 4, the semiconductor laser element 10 is bonded to the third drive conductive portion 63 with a conductive bonding material such as Ag (silver) paste or solder. Specifically, the semiconductor laser element 10 is disposed closer to the first substrate side surface 51c than the intermediate connecting portion 75c of the semiconductor laser element mounting portion 63b of the third drive conductive portion 63. When viewed from the lateral direction X, the semiconductor laser element 10 overlaps with the fourth drive conductive portions 64A and 64B and also with the second terminals 32 of the capacitors 30A and 30B. The semiconductor laser element 10 is disposed so that the cathode electrode 12 faces the third drive conductive portion 63 in the thickness direction Z. The cathode electrode 12 of the semiconductor laser element 10 is bonded to the third drive conductive portion 63 with a conductive bonding material.

[0070] The switching element 20 is bonded to the third drive conductive portion 63 with a conductive adhesive such as Ag paste or solder. Specifically, the semiconductor laser element 10 is mounted closer to the second substrate side surface 51d than the intermediate connecting portion 75c of the switching element mounting portion 63a of the third drive conductive portion 63. When viewed from the lateral direction X, the switching element 20 overlaps the first drive conductive portions 61A and 61B and also overlaps the first terminals 31 of the capacitors 30A and 30B. The switching element 20 is disposed so that the drain electrode 21 faces the third drive conductive portion 63 in the thickness direction Z. The drain electrode 21 is bonded to the third drive conductive portion 63 with a conductive adhesive. In this way, the drain electrode 21 and the cathode electrode 12 of the semiconductor laser element 10 are electrically connected via the third drive conductive portion 63.

[0071] 2, the anode electrode 11 of the semiconductor laser element 10 and the source electrode 22 and gate electrode 23 of the switching element 20 each face away from the support substrate 50 in the thickness direction Z. The anode electrode 11, source electrode 22, and gate electrode 23 are electrically connected to the first drive conductive portions 61A and 61B, the second drive conductive portion 62, the fourth drive conductive portions 64A and 64B, and the control conductive portion 65 via the connection member 80.

[0072] The connection members 80 include first drive connection members 81 and 82, a second drive connection member 83, a control connection member 84, and laser connection members 85 and 86. The connection members 80 are wires made of metal such as Au (gold), Cu (copper), or Al (aluminum). In this embodiment, the connection members 80 are formed by wire bonding.

[0073] The first drive connection members 81 connect the source electrode 22 and the first drive conductive portion 61A. While the number of first drive connection members 81 is not particularly limited, there are three in this embodiment. The three first drive connection members 81 are arranged at intervals in the vertical direction Y. The first drive connection members 81 have a first end 81a and a second end 81b. The first end 81a is joined to the source electrode 22. The second end 81b is joined to the first drive conductive portion 61A. The first end 81a of each of the three first drive connection members 81 is located closer to the semiconductor laser element 10 in the vertical direction Y than the gate electrode 23 of the source electrode 22, and closer to the first drive conductive portion 61A in the horizontal direction X than the gate electrode 23. The second ends 81b of the three first drive connecting members 81 are each disposed closer to the control conductive portion 65 in the vertical direction Y than the capacitor 30A of the first drive conductive portion 61A, and closer to the switching element 20 in the horizontal direction X than the first drive linking portion 73A. When viewed from the vertical direction Y, the second ends 81b are disposed so as to overlap with a portion of the capacitor 30A that is closer to the switching element 20 than the center of the capacitor 30A in the horizontal direction X.

[0074] The first drive connection members 82 connect the source electrode 22 and the first drive conductive portion 61B. While the number of first drive connection members 82 is not particularly limited, it is three in this embodiment. That is, the number of first drive connection members 82 is equal to the number of first drive connection members 81. The three first drive connection members 82 are arranged at intervals in the vertical direction Y. The first drive connection members 82 have a first end 82a and a second end 82b. The first end 82a is joined to the source electrode 22. The second end 82b is joined to the first drive conductive portion 61B. The first end 82a of each of the three first drive connection members 82 is located closer to the semiconductor laser element 10 in the vertical direction Y than the gate electrode 23 of the source electrode 22 and closer to the first drive conductive portion 61B in the horizontal direction X than the gate electrode 23. The second ends 82b of the three first drive connecting members 82 are each disposed closer to the second drive conductive portion 62 in the vertical direction Y than the capacitor 30B of the first drive conductive portion 61B, and closer to the switching element 20 in the horizontal direction X than the first drive linking portion 73B. When viewed from the vertical direction Y, the second ends 82b are disposed so as to overlap with a portion of the capacitor 30B that is closer to the switching element 20 than the center of the capacitor 30B in the horizontal direction X.

[0075] The second drive connection member 83 connects the source electrode 22 and the second drive conductive portion 62. While the number of second drive connection members 83 is not particularly limited, in this embodiment, there is one. The second drive connection member 83 is arranged closer to the second substrate side surface 51d than the three first drive connection members 81. The second drive connection member 83 has a first end 83a and a second end 83b. The first end 83a is joined to the source electrode 22. The second end 83b is joined to the second drive conductive portion 62. The first end 83a is arranged at an end of the source electrode 22 closer to the second drive conductive portion 62 in the vertical direction Y. The second end 83b is arranged at an end of the second drive conductive portion 62 closer to the switching element 20 in the vertical direction Y, and at a portion of the second drive conductive portion 62 that overlaps with the source electrode 22 when viewed from the vertical direction Y. In this embodiment, the second end 83b is located in a portion of the second drive conductive portion 62 closer to the control conductive portion 65 than the three second drive connecting portions 74.

[0076] The control connection member 84 connects the gate electrode 23 and the control conductive portion 65. There is no particular limitation on the number of control connection members 84, but in this embodiment, there is one. The control connection member 84 has a first end 84a and a second end 84b. The first end 84a is joined to the gate electrode 23. The second end 84b is located at an end of the control conductive portion 65 closer to the second drive conductive portion 62 in the horizontal direction X. In this embodiment, the second end 84b is located at a portion of the control conductive portion 65 closer to the second drive conductive portion 62 than the three control link portions 77.

[0077] The laser connecting member 85 connects the anode electrode 11 of the semiconductor laser element 10 and the fourth drive conductive portion 64A. While the number of laser connecting members 85 is not particularly limited, two are used in this embodiment. The two laser connecting members 85 are arranged at an interval in the vertical direction Y. Each laser connecting member 85 has a first end 85a and a second end 85b. The first end 85a is connected to the anode electrode 11. Specifically, the first end 85a is located at the center of the anode electrode 11 in the horizontal direction X. The second end 85b is connected to the fourth drive conductive portion 64A. Specifically, the second end 85b is located at a portion of the fourth drive conductive portion 64A that is closer to the semiconductor laser element 10 in the horizontal direction X than the center of the fourth drive conductive portion 64A in the horizontal direction X.

[0078] The laser connecting member 86 connects the anode electrode 11 and the fourth drive conductive portion 64B. While the number of laser connecting members 86 is not particularly limited, in this embodiment, there are two. The two laser connecting members 86 are arranged at an interval in the vertical direction Y. Each laser connecting member 86 has a first end 86a and a second end 86b. The first end 86a is connected to the anode electrode 11. Specifically, the first end 86a is disposed in the center of the anode electrode 11 in the horizontal direction X. In a plan view, the first end 85a of the laser connecting member 85 and the first end 86a of the laser connecting member 86 are arranged alternately in the vertical direction Y. The second end 86b is connected to the fourth drive conductive portion 64B. Specifically, the second end 86b is disposed in a portion of the fourth drive conductive portion 64B that is closer to the semiconductor laser element 10 in the lateral direction X than the center portion of the fourth drive conductive portion 64B in the lateral direction X.

[0079] As shown in FIGS. 4 to 8 , the sealing member 90 is laminated on the base material main surface 51a of the base material 51 of the support substrate 50 in the thickness direction Z. The sealing member 90 transmits the pulsed laser light of the semiconductor laser element 10 and seals the main surface-side conductive portion 60A, the semiconductor laser element 10, the switching element 20, the capacitor 30, and the connecting member 80. That is, the sealing member 90 is configured so that the portion from which the pulsed laser light of the semiconductor laser element 10 is output is transparent or translucent. The portions of the sealing member 90 other than the portion from which the pulsed laser light is output do not need to be transparent or translucent. In this way, the sealing member 90 may be configured of two types of members: a transparent or translucent portion and a light-opaque portion. In this embodiment, the sealing member 90 is configured so that the entire sealing member is transparent or translucent. The sealing member 90 is made of a material such as a transparent epoxy resin or a silicone resin, for example.

[0080] The sealing member 90 has a sealing main surface 91, a first sealing side surface 92, a second sealing side surface 93, a third sealing side surface 94, and a fourth sealing side surface 95. The sealing main surface 91 is a surface of the sealing member 90 facing away from the support substrate 50 in the thickness direction Z. That is, the sealing main surface 91 faces the same direction as the element main surface 24a of the switching element 20. Each of the sealing side surfaces 92 to 95 is a surface formed between the sealing main surface 91 and the support substrate 50 in the thickness direction Z and extends in a direction intersecting the sealing main surface 91. The first sealing side surface 92 and the second sealing side surface 93 face opposite each other in the vertical direction Y. The first sealing side surface 92 faces the same direction as the first substrate side surface 51c of the substrate 51 in the vertical direction Y. The second sealing side surface 93 faces the same direction as the second substrate side surface 51d of the substrate 51 in the vertical direction Y. The third sealing side surface 94 and the fourth sealing side surface 95 are surfaces facing opposite each other in the lateral direction X. The third sealing side surface 94 is a surface facing the same direction as the third base side surface 51e of the base material 51 in the lateral direction X. The fourth sealing side surface 95 is a surface facing the same direction as the fourth base side surface 51f of the base material in the lateral direction X. In this embodiment, the laser light L from the semiconductor laser element 10 is emitted from the first sealing side surface 92 of the sealing member 90. Furthermore, in this embodiment, the first sealing side surface 92 of the sealing member 90 is a flat and smooth surface. This makes it possible to suppress scattering of the laser light L and increase the emission efficiency of the laser light.

[0081] Next, an example of the detailed configuration of the semiconductor laser device 10 will be described. 9 and 10, semiconductor laser device 10 includes substrate 13 and mesa-shaped semiconductor light emitting layer 14 stacked on substrate 13 in thickness direction Z. Semiconductor light emitting layer 14 corresponds to a light emitting portion.

[0082] The substrate 13 is an n-type semiconductor substrate containing GaAs (gallium arsenide), and contains at least one of Si (silicon), Te (tellurium), and Se (selenium) as n-type impurities.

[0083] The semiconductor light emitting layer 14 generates laser light L. The semiconductor light emitting layer 14 generates laser light L having a peak wavelength of 0.7 μm or more and 2.5 μm or less. That is, the semiconductor light emitting layer 14 generates laser light L in the near-infrared region. Preferably, the semiconductor light emitting layer 14 generates laser light L having a peak wavelength of 800 nm or more and 1000 nm or less. That is, the semiconductor light emitting layer 14 generates laser light L in the infrared region. The semiconductor light emitting layer 14 has a mesa structure 15 including an n-type buffer layer 14a, a first light emitting unit layer 14b, a first tunnel junction layer 14c, a second light emitting unit layer 14d, a second tunnel junction layer 14e, a third light emitting unit layer 14f, and a p-type contact layer 14g.

[0084] The n-type buffer layer 14a is stacked on the substrate 13. The n-type buffer layer 14a contains GaAs. The n-type buffer layer 14a contains at least one of Si, Te, and Se as an n-type impurity. The n-type impurity concentration of the n-type buffer layer 14a is, for example, 1×10 18 cm -3 More than 1×10 19 cm -3 The following is the result.

[0085] Each of the light-emitting unit layers 14b, 14d, and 14f generates laser light L through recombination of holes and electrons. The first light-emitting unit layer 14b, the second light-emitting unit layer 14d, and the third light-emitting unit layer 14f are stacked in this order on the n-type buffer layer 14a. As shown by the white arrows in FIG. 10 , each of the light-emitting unit layers 14b, 14d, and 14f emits laser light along the lateral direction X.

[0086] A first tunnel junction layer 14c and a second tunnel junction layer 14e are interposed between adjacent light-emitting units in the stacking direction. Specifically, the first tunnel junction layer 14c is interposed between the first light-emitting unit layer 14b and the second light-emitting unit layer 14d, and the second tunnel junction layer 14e is interposed between the second light-emitting unit layer 14d and the third light-emitting unit layer 14f. Each of the tunnel junction layers 14c and 14e generates a tunnel current due to the tunnel effect, and the tunnel current flows through each of the light-emitting unit layers 14b, 14d, and 14f.

[0087] The p-type contact layer 14g is formed on the third light-emitting unit layer 14f. The p-type contact layer 14g includes GaAs. The p-type contact layer 14g includes C (carbon) as a p-type impurity.

[0088] The semiconductor light emitting layer 14 is covered with an insulating layer 16. The insulating layer 16 is formed in a film shape. The insulating layer 16 may contain silicon oxide such as Si3N4 (silicon nitride) or SiO2 or SiO. In this embodiment, the insulating layer 16 contains silicon nitride. A contact opening 16a exposing the semiconductor light emitting layer 14 is formed in the insulating layer 16 in a portion covering the top of the mesa structure 15. A contact electrode 17 is formed in the contact opening 16a. The contact electrode 17 is electrically connected to the semiconductor light emitting layer 14. The contact electrode 17 is extended onto the insulating layer 16 from the contact opening 16a. An anode electrode 11 (see FIGS. 4 and 6) is formed on the contact electrode 17. A cathode electrode 12 (see FIGS. 4 and 6) is formed on the back surface of the substrate 13, on the side opposite the mesa structure with respect to the substrate 13 in the thickness direction.

[0089] (action) Next, the operation of the semiconductor laser device 1A of this embodiment will be described. 11 shows a schematic circuit diagram of a semiconductor laser device 1X of the comparative example applied to a laser system 100. The semiconductor laser device 1X of the comparative example is comparable to the semiconductor laser device 1A of this embodiment, and differs in that the input electrode 142 of the driver circuit 140 is connected to the negative electrode of the power supply 110 and the capacitor 30 in the circuit.

[0090] Fig. 12 is a graph showing the transition of the current flowing through the semiconductor laser element 10 when the laser system 100 employing the semiconductor laser device 1X of the comparative example is driven, and the transition of the voltage applied to the gate electrode 23 of the switching element 20. Fig. 13 is a graph showing the transition of the voltage applied to the first drive connecting members 81, 82 when the laser system 100 employing the semiconductor laser device 1X of the comparative example is driven.

[0091] As shown in FIG. 11 , when power is supplied from a power supply 110 of a laser system 100 incorporating the semiconductor laser device 1X of the comparative example to the semiconductor laser device 1X, charge is stored in the capacitor 30 when the switching element 20 is in the off state, and the charge stored in the capacitor 30 flows to the semiconductor laser element 10 and the switching element 20 when the switching element 20 is in the on state. Here, when laser light is emitted with a short pulse width, for example, 10 ns, the current flowing through the semiconductor laser element 10 rises sharply. This causes a large electromotive force to be generated in the parasitic inductance of the semiconductor laser device 1X. This causes a large pulse current to also flow through the switching element 20, generating an electromotive force VLs in the inductance between the source electrode 22 and the first terminal 31 of the capacitor 30 (30A, 30B), i.e., the parasitic inductance due to the first drive connecting members 81, 82. In this case, even if the gate electrode 23 of the switching element 20 is applied with the voltage Vg between the input electrode 142 and the output electrode 141 of the driver circuit 140, the voltage Vgs (control voltage) actually applied to the gate electrode 23 becomes Vg-VLs due to the electromotive force VLs. This decrease in voltage Vgs causes the charge in the capacitor 30 to flow to the semiconductor laser element 10 and the switching element 20 without sufficiently decreasing the on-resistance of the switching element 20, thereby reducing the current ILD flowing through the semiconductor laser element 10. That is, as shown in FIGS. 12 and 13 , when the voltage Vgs rises from time t1 to time t2, the gate current flows, generating the electromotive force VLs. Then, when the current ILD rises sharply from time t3 to time t4, the electromotive force VLs rises sharply, causing the voltage Vgs to drop sharply from time t3 to time t4. As a result, the peak value of the current ILD does not become large.

[0092] 14, in the present embodiment, when the semiconductor laser device 1A is applied to the laser system 100, the positive electrode 111 of the power supply 110 is connected to the fourth drive conductive portion 64A via the fourth terminal conductive portion 69A and the fourth drive connecting portion 76A (both see FIG. 3), and the negative electrode 112 of the power supply 110 is connected to the first drive conductive portion 61A via the first terminal conductive portion 66A and the first drive connecting portion 73A (both see FIG. 3). In addition, the output electrode 141 of the driver circuit 140 is connected to the control conductive portion 65 via the control terminal conductive portion 70 and the control connecting portion 77 (both see FIG. 3), and the input electrode 142 is connected to the second drive conductive portion 62 via the second terminal conductive portion 67 and the second drive connecting portion 74 (both see FIG. 3). 15, when power is supplied from the power supply 110 to the semiconductor laser device 1A, the capacitors 30A and 30B are charged when the switching element 20 is in the off state, and the charges charged in the capacitors 30A and 30B flow to the semiconductor laser element 10 and the switching element 20 when the switching element 20 is in the on state. More specifically, a first driving loop in which a current based on the charge charged in the capacitor 30A flows to the semiconductor laser element 10 and the switching element 20, and a second driving loop in which a current based on the charge charged in the capacitor 30B flows to the semiconductor laser element 10 and the switching element 20 are separately formed. Specifically, in the first drive loop, current flows in the following order: second terminal 32 of capacitor 30A, fourth drive conductive part 64A, laser connecting member 85, anode electrode 11 and cathode electrode 12 of semiconductor laser element 10, third drive conductive part 63, drain electrode 21 and source electrode 22 of switching element 20, first drive connecting member 81, and first terminal 31 of capacitor 30A. In the second drive loop, current flows in the following order: second terminal 32 of capacitor 30A, fourth drive conductive part 64B, laser connecting member 86, anode electrode 11 and cathode electrode 12 of semiconductor laser element 10, third drive conductive part 63, drain electrode 21 and source electrode 22 of switching element 20, first drive connecting member 82, and first terminal 31 of capacitor 30B. Then, current flows from source electrode 22 of switching element 20 to the negative electrode of power supply 110 via first drive conductive part 61A.

[0093] Meanwhile, voltage Vg is generated between input electrode 142 and output electrode 141 of driver circuit 140, and voltage Vgs, which is a gate-source voltage, is applied to gate electrode 23 of switching element 20. Specifically, a control loop is formed between driver circuit 140 and switching element 20, in which current flows in the following order: output electrode 141 of driver circuit 140, control terminal conductive portion 70, control linking portion 77, control conductive portion 65, control connecting member 84, gate electrode 23, source electrode 22, second drive connecting member 83, second drive conductive portion 62, second drive linking portion 74, second terminal conductive portion 67, and input electrode 142. In this way, input electrode 142 and source electrode 22 are electrically connected independently of the first drive loop and the second drive loop, and therefore voltage Vgs applied to gate electrode 23 is generated based on the potential of source electrode 22 connected to input electrode 142.

[0094] In this way, the first and second drive loops for the current between the power supply 110 and the semiconductor laser element 10 and the switching element 20, and the control loop for the current between the driver circuit 140 and the switching element 20 are formed separately, so that the voltage Vg applied to the input electrode 142 of the driver circuit 140 and the voltage Vgs applied to the gate electrode 23 are less likely to be affected by the first drive loop and the second drive loop, respectively. That is, because the second drive connecting member 83 electrically connects the input electrode 142 and the source electrode 22, the driver circuit 140 is less likely to be affected by the electromotive voltage VLs due to the parasitic inductance Ls caused by the first drive connecting members 81 and 82.

[0095] 15, the voltage Vgs rises more quickly than the voltage Vgs of the semiconductor laser device 1X of the comparative example, and there is almost no voltage drop due to the electromotive force VLs. Therefore, the peak value of the current ILD flowing through the semiconductor laser element 10 of this embodiment is greater than the peak value of the current ILD flowing through the semiconductor laser element 10 of the semiconductor laser device 1X of the comparative example. The current ILD also rises more sharply. Additionally, since the voltage Vgs rises quickly and there is no significant drop in the voltage Vgs in this embodiment, the pulse width PW of the current ILD of this embodiment is smaller than the pulse width PW of the current ILD of the semiconductor laser device 1X of the comparative example.

[0096] (effect) According to the semiconductor laser device 1A of this embodiment, the following effects can be obtained. (1-1) The semiconductor laser device 1A includes first drive connecting members 81 and 82 that connect the source electrode 22 of the switching element 20 to the first drive conductive members 61A and 61B, and a second drive connecting member 83 that connects the source electrode 22 to the second drive conductive member 62. This configuration provides a first drive loop and a second drive loop that are a first path for current flowing from the source electrode 22 of the switching element 20 to the first drive conductive members 61A and 61B via the first drive connecting members 81 and 82, and a control loop that is a second path for current flowing from the source electrode 22 to the second drive conductive member 62 via the second drive connecting member 83. This reduces the influence of fluctuations in the currents in the first drive loop and the second drive loop on the control loop. In other words, the control loop is less susceptible to the influence of the inductance of the first drive connecting members 81 and 82. Therefore, in the control loop, the influence of the counter electromotive voltage (electromotive voltage VLs) caused by the inductance of the first drive connecting members 81 and 82 on the voltage Vgs applied to the gate electrode 23 of the switching element 20 can be reduced.

[0097] (1-2) In the vertical direction Y, the second driving conductive portion 62 is disposed on the opposite side of the switching element 20 from the semiconductor laser element 10. With this configuration, the control loop can be formed at a position far from the first driving loop and the second driving loop. Therefore, the control loop is less likely to be affected by the first driving loop and the second driving loop.

[0098] (1-3) The semiconductor laser device 1A includes capacitors 30A and 30B. With this configuration, compared to a single capacitor, the parallel connection of the capacitors 30A and 30B can reduce the effect of the parasitic inductance of the capacitors 30A and 30B, allowing a current with a larger peak and a smaller pulse width to flow through the semiconductor laser element 10. This allows the application of a semiconductor laser element 10 with a higher output.

[0099] (1-4) The capacitors 30A and 30B are arranged closer to the semiconductor laser element 10 than the switching element 20 in the vertical direction Y. With this configuration, the first drive loop and the second drive loop can be formed at positions farther away from the control loop. Therefore, the control loop is less susceptible to the influence of the first drive loop and the second drive loop. In addition, since the lengths of the current paths in the first drive loop and the second drive loop are shortened, the inductance of the semiconductor laser device 1A can be reduced.

[0100] (1-5) Capacitors 30A and 30B are arranged on both sides of the switching element 20 in the horizontal direction X, and first drive conductive portions 61A and 61B are arranged on both sides of the switching element 20 in the horizontal direction X. A first drive connection member 81 connects the source electrode 22 of the switching element 20 to the first drive conductive portion 61A, and a first drive connection member 82 connects the source electrode 22 to the first drive conductive portion 61B. With this configuration, two drive loops, a first drive loop and a second drive loop, are formed as current paths. Therefore, compared to a single drive loop, the lengths of the first drive loop and the second drive loop are shorter, and the currents in the first drive loop and the second drive loop can be balanced.

[0101] (1-6) The semiconductor laser device 1A includes a third drive conductor 63 that connects the drain electrode 21 of the switching element 20 and the cathode electrode 12 of the semiconductor laser element 10. With this configuration, the third drive conductor 63 can connect the drain electrode 21 and the cathode electrode 12 over the shortest distance, and the cross-sectional area of ​​the third drive conductor 63 can be made larger than that of a wire. Therefore, the inductance between the cathode electrode 12 and the drain electrode 21 can be reduced.

[0102] (1-7) The control conductive portion 65 and the second drive conductive portion 62 are adjacent to each other in the horizontal direction X. With this configuration, the current path that constitutes the control loop can be made smaller, thereby reducing the inductance in the control loop.

[0103] Furthermore, the second drive conductive portion 62 is arranged closer to the control conductive portion 65 than the first drive connecting member 82 that is closest to the capacitors 30A, 30B among the plurality of first drive connecting members 82. With this configuration, the control loop is less susceptible to the influence of the second drive loop.

[0104] (1-8) Each of the first drive connecting members 81 and 82 is made of a plurality of wires. This configuration reduces the inductance between the first drive conductive portion 61A and the source electrode 22 of the switching element 20, and the inductance between the first drive conductive portion 61B and the source electrode 22.

[0105] (1-9) The wire diameter of the first drive connecting members 81, 82 and the wire diameter of the second drive connecting member 83 are equal to each other. With this configuration, when the first drive connecting members 81, 82 and the second drive connecting member 83 are formed by wire bonding, there is no need to change the wire material. Therefore, the process of forming the first drive connecting members 81, 82 and the second drive connecting member 83 can be simplified.

[0106] (1-10) The wire diameters of the first drive connecting members 81, 82, the second drive connecting member 83, and the laser connecting members 85, 86 are all equal. With this configuration, when forming each of the drive connecting members 81-83 and the laser connecting members 85, 86 by wire bonding, there is no need to change the wire material. Therefore, the process of forming each of the drive connecting members 81-83 and the laser connecting members 85, 86 can be simplified.

[0107] (1-11) The wire diameters of the first drive connecting members 81 and 82, the second drive connecting member 83, the control connecting member 84, and the laser connecting members 85 and 86 are all equal to one another. With this configuration, when forming each of the connecting members 81 to 86 by wire bonding, there is no need to change the wire material. Therefore, the process of forming each of the connecting members 81 to 86 can be simplified.

[0108] (1-12) The ends of the fourth drive conductive parts 64A, 64B closer to the semiconductor laser element 10 are close to the semiconductor laser element 10 in plan view. The laser connecting member 85 is joined to the end of the fourth drive conductive part 64A closer to the semiconductor laser element 10, and the laser connecting member 86 is joined to the end of the fourth drive conductive part 64B closer to the semiconductor laser element 10. With this configuration, the lengths of the laser connecting members 85, 86 can be shortened, and therefore the inductance caused by the laser connecting members 85, 86 can be reduced.

[0109] (1-13) The gap between adjacent back-side conductive portions 60B on the base back surface 51b of the base material 51 of the support substrate 50 is larger than the gap between adjacent main-surface-side conductive portions 60A on the base main surface 51a. This prevents a conductive bonding member such as solder from being formed to connect adjacent back-side conductive portions 60B when mounted on a wiring board. This makes it less likely that a short circuit will occur.

[0110] In other words, the gap between adjacent main surface-side conductive portions 60A on the substrate main surface 51a is smaller than the gap between adjacent back surface-side conductive portions 60B on the substrate back surface 51b. This allows the length of the first drive connecting members 81 and 82 connecting the switching element 20 to the first drive conductive portions 61A and 61B to be shortened. The length of the first drive connecting member 82 connecting the switching element 20 to the second drive conductive portion 62 can also be shortened. The length of the control connecting member 84 connecting the switching element 20 to the control conductive portion 65 can also be shortened. The lengths of the laser connecting members 85 and 86 connecting the semiconductor laser element 10 to the fourth drive conductive portions 64A and 64B can also be shortened. This reduces the inductance caused by each connecting member 81 to 86. Additionally, the shorter length of the control connecting member 84 reduces the likelihood of noise occurring in signals from the driver circuit 140.

[0111] (1-14) The semiconductor laser element 10 is disposed at the center of the base material 51 in the lateral direction X. This configuration eliminates the deviation of the semiconductor laser element 10 relative to the support substrate 50 in the lateral direction X, allowing the wiring pattern of the wiring board to be designed without taking the deviation of the semiconductor laser element 10 into consideration. This improves the usability of the semiconductor laser device 1A.

[0112] (1-15) The semiconductor laser element 10 can emit laser light with a pulse width of 10 ns or less. This configuration can improve the accuracy of two-dimensional or three-dimensional distance measurement using the semiconductor laser device 1A.

[0113] On the other hand, in such a semiconductor laser element 10, the pulse width is short, so that the temporal change of the current ILD flowing through the semiconductor laser element 10 tends to be steep. That is, the influence of the inductance Ls between the first terminal 31 of the capacitors 30A, 30B and the source electrode 22 of the switching element 20 on the voltage Vg applied to the gate electrode 23 of the switching element 20 becomes large. However, in this embodiment, as described above, the first driving loop, the second driving loop, and the control loop are formed separately, thereby reducing the influence of the inductance Ls on the voltage Vg, and therefore the current ILD flowing through the semiconductor laser element 10 can be increased.

[0114] [Modification of the first embodiment] The semiconductor laser device 1A of the first embodiment can be modified, for example, as follows. The following modifications can be combined as long as no technical contradiction occurs. In the following modifications, parts common to the first embodiment are assigned the same reference numerals as in the first embodiment, and their description will be omitted.

[0115] In the first embodiment, the semiconductor laser device 1A is configured to include one semiconductor laser element 10, but the number of semiconductor laser elements 10 is not particularly limited and can be changed as desired. That is, the semiconductor laser device 1A may include a plurality of semiconductor laser elements 10. In one example, as shown in FIG. 17, the semiconductor laser device 1A includes two semiconductor laser elements 10A and 10B.

[0116] 17, the shapes of the third drive conductive portion 63 and the fourth drive conductive portions 64A, 64B in a plan view are different from those of the third drive conductive portion 63 and the fourth drive conductive portions 64A, 64B of the first embodiment. Specifically, the size in the lateral direction X of the semiconductor laser element mounting portion 63b of the third drive conductive portion 63 is increased in order to mount the semiconductor laser elements 10A, 10B. Meanwhile, in accordance with the increase in the size in the lateral direction X of the semiconductor laser element mounting portion 63b, the size in the lateral direction X of the fourth drive conductive portions 64A, 64B is reduced. This makes it possible to prevent the semiconductor laser device 1A including the semiconductor laser elements 10A, 10B from becoming larger.

[0117] The semiconductor laser elements 10A and 10B are each mounted on the semiconductor laser element mounting portion 63b with a conductive adhesive. The semiconductor laser elements 10A and 10B are aligned in the vertical direction Y and spaced apart in the horizontal direction X. The semiconductor laser elements 10A and 10B are each arranged such that their cathode electrodes 12 (not shown in FIG. 17) face the semiconductor laser element mounting portion 63b. Therefore, the cathode electrodes 12 of the semiconductor laser elements 10A and 10B are electrically connected to the semiconductor laser element mounting portion 63b. That is, the cathode electrode 12 of the semiconductor laser element 10A and the cathode electrode 12 of the semiconductor laser element 10B are electrically connected.

[0118] The semiconductor laser element 10A is disposed on the semiconductor laser element mounting portion 63b on the side facing the fourth drive conductive portion 64A in the horizontal direction X. The anode electrode 11 of the semiconductor laser element 10A and the fourth drive conductive portion 64A are electrically connected by four laser connecting members 85. The four laser connecting members 85 are arranged at intervals in the vertical direction Y.

[0119] The semiconductor laser element 10B is disposed on the semiconductor laser element mounting portion 63b on the side of the fourth drive conductive portion 64B in the horizontal direction X. The anode electrode 11 of the semiconductor laser element 10B and the fourth drive conductive portion 64B are electrically connected by four laser connecting members 86. The four laser connecting members 86 are arranged at intervals in the vertical direction Y.

[0120] As shown in Figure 18, the shape of the back side conductive portion 60B when viewed from the thickness direction Z, i.e., the shape of each terminal conductive portion 66A, 66B, 67, 68, 69A, 69B, 70 when viewed from the thickness direction Z, is the same as the shape of each terminal conductive portion 66A, 66B, 67, 68, 69A, 69B, 70 when viewed from the thickness direction Z in the first embodiment.

[0121] On the other hand, the number and arrangement of the third drive connecting portions 75 as the connecting portion 60C differ from the third drive connecting portions 75 of the first embodiment. Specifically, the number of switching element side connecting portions 75a is smaller than the number of switching element side connecting portions 75a of the first embodiment. In FIG. 18, four switching element side connecting portions 75a are provided at positions overlapping with the switching elements 20 in the thickness direction Z. The number of semiconductor laser element side connecting portions 75b is greater than the number of semiconductor laser element side connecting portions 75b of the first embodiment. In FIG. 18, the semiconductor laser element side connecting portions 75b are provided at positions overlapping with the semiconductor laser element 10A in the thickness direction Z and at positions overlapping with the semiconductor laser element 10B in the thickness direction Z.

[0122] In this way, according to the semiconductor laser device 1A including a plurality of semiconductor laser elements 10 as shown in FIGS. 17 and 18, the intensity of the laser light emitted from the semiconductor laser device 1A is increased.

[0123] 19, an element connecting member 87 may be added to connect the anode electrode 11 of the semiconductor laser element 10A to the anode electrode 11 of the semiconductor laser element 10B. The element connecting member 87 is a wire made of a metal such as gold (Au), copper (Cu), or aluminum (Al). The element connecting member 87 is formed by wire bonding. The number of element connecting members 87 is not particularly limited, but one is shown in FIG. 19. The wire diameter of the element connecting member 87 is not particularly limited, but may be equal to the wire diameter of the laser connecting members 85 and 86, for example. Here, if the difference between the wire diameter of the element connecting member 87 and the wire diameter of the laser connecting members 85 and 86 is within 5% of the wire diameter of the laser connecting members 85 and 86, for example, it can be said that the wire diameter of the element connecting member 87 is equal to the wire diameter of the laser connecting members 85 and 86. The configuration and shape of the back-side conductive portion 60B of the semiconductor laser device 1A shown in FIG. 19 are the same as those of the back-side conductive portion 60B of the semiconductor laser device 1A of the modified example shown in FIG.

[0124] 19, the anode electrode 11 of the semiconductor laser element 10A and the anode electrode 11 of the semiconductor laser element 10B are connected by the element connection member 87, and therefore the fourth drive conductive parts 64A and 64B are electrically connected via the semiconductor laser elements 10A and 10B. This makes it possible to connect the positive electrode of the power supply 110 to only the fourth drive conductive part 64A when connecting the positive electrode of the power supply 110 to the semiconductor laser device 1A, thereby simplifying the connection structure between the power supply 110 and the semiconductor laser device 1A.

[0125] In the modification of FIG. 17 , the semiconductor laser device 1A may include a semiconductor laser element having a plurality of semiconductor light emitting layers 14 arranged side by side in the horizontal direction X and one electrode connecting the plurality of semiconductor light emitting layers 14. In one example, as shown in FIG. 20 , the semiconductor laser device 1A may include a semiconductor laser element 10C having two semiconductor light emitting layers 14A and 14B (see FIG. 21 ). As shown in FIG. 20 , the shape of the semiconductor laser element 10C in plan view is rectangular, with the longer side extending in the horizontal direction X and the shorter side extending in the vertical direction Y. The size of the semiconductor laser element 10C in the horizontal direction X is larger than the size of the semiconductor laser element 10 of the first embodiment in the horizontal direction X.

[0126] As shown in FIG. 21 , the semiconductor laser device 10C includes a substrate 13 and semiconductor light-emitting layers 14A and 14B arranged side by side on the substrate 13 in the lateral direction X. The semiconductor light-emitting layers 14A and 14B have the same configuration as the semiconductor light-emitting layer 14 of the first embodiment. An insulating layer 16 covers both the semiconductor light-emitting layers 14A and 14B. A contact opening 16b is formed in the insulating layer 16 at the top of the semiconductor light-emitting layer 14A, and a contact opening 16c is formed in the insulating layer 16 at the top of the semiconductor light-emitting layer 14B. The contact opening 16b exposes the semiconductor light-emitting layer 14A, and the contact opening 16c exposes the semiconductor light-emitting layer 14B. A contact electrode 17 is formed in the contact openings 16b and 16c. The contact electrode 17 is formed on the insulating layer 16 from the contact opening 16b to the contact opening 16c. Therefore, the contact electrode 17 is electrically connected to both the semiconductor light-emitting layers 14A and 14B. That is, contact electrode 17 corresponds to one electrode that connects a plurality of semiconductor light emitting layers 14. On contact electrode 17, anode electrode 11 (see FIG. 20) is formed.

[0127] 20 and 21, the semiconductor laser device 1A has a single semiconductor laser element on one chip, and no connecting member is required to connect the anode electrodes of the two semiconductor laser elements together, thereby simplifying the configuration of the semiconductor laser device 1A compared to the semiconductor laser device 1A shown in FIGS. 17 to 19.

[0128] The configuration of the back-side conductive portion 60B can be changed as desired. In one example, the back-side conductive portion 60B may integrate the first terminal conductive portion 66B and the third terminal conductive portion 68. For example, as shown in FIG. 22, the semiconductor laser device 1A may include a terminal conductive portion 78 that integrates the first terminal conductive portion 66B, the third terminal conductive portion 68, and the fourth terminal conductive portion 69B (all see FIG. 3). In this case, the shape of the terminal conductive portion 78 in plan view is rectangular with the longer side extending in the horizontal direction X and the shorter side extending in the vertical direction Y. Note that the shape of the terminal conductive portion 78 in plan view can be changed as desired. For example, the shape of the terminal conductive portion 78 in plan view may be square. The area of ​​the terminal conductive portion 78 in plan view is greater than the sum of the areas of the first terminal conductive portion 66B, the third terminal conductive portion 68, and the fourth terminal conductive portion 69B in plan view of the first embodiment. Therefore, the heat dissipation performance of the semiconductor laser device 1A due to the terminal conductive portion 78 is improved.

[0129] Furthermore, since the terminal conductive portion 78 electrically connects the third terminal conductive portion 68 to the first terminal conductive portion 66B and the fourth terminal conductive portion 69B, the first drive connecting portion 73B and the fourth drive connecting portion 76B (see FIG. 3) can be omitted. This simplifies the configuration of the semiconductor laser device 1A. Note that a first drive connecting portion 73B that connects the terminal conductive portion 78 to the first drive conductive portion 61B and a fourth drive connecting portion 76B that connects the terminal conductive portion 78 to the fourth drive conductive portion 64B may be added.

[0130] The configuration connecting the main surface-side conductive portion 60A and the back surface-side conductive portion 60B is not limited to the through hole 71. For example, as shown in FIGS. 23 and 24 , a side surface connecting portion 60D may be provided in place of a portion of the connecting portion 60C. The side surface connecting portion 60D is formed on the second substrate side surface 51d, the third substrate side surface 51e, and the fourth substrate side surface 51f of the substrate 51, respectively. In this case, the arrangement of the main surface-side conductive portion 60A and the back surface-side conductive portion 60B relative to the substrate 51 is different.

[0131] Specifically, the second drive conductive portion 62 and the control conductive portion 65 are arranged differently from the second terminal conductive portion 67 and the control terminal conductive portion 70. More specifically, when viewed from the lateral direction X, the second drive conductive portion 62 and the control conductive portion 65 each overlap the third drive conductive portion 63. The second drive conductive portion 62 is arranged closer to the fourth substrate side surface 51f than the third drive conductive portion 63 in the lateral direction X. The control conductive portion 65 is arranged closer to the third substrate side surface 51e than the third drive conductive portion 63 in the lateral direction X. The second terminal conductive portion 67 is arranged to overlap the second drive conductive portion 62 in the thickness direction Z. The control terminal conductive portion 70 is arranged to overlap the control conductive portion 65 in the thickness direction Z. In this way, when viewed from the lateral direction X, the second terminal conductive portion 67 and the control terminal conductive portion 70 each overlap the third terminal conductive portion 68. The second terminal conductive portion 67 is disposed closer to the fourth substrate side surface 51f in the horizontal direction X than the third terminal conductive portion 68. The control terminal conductive portion 70 is disposed closer to the third substrate side surface 51e in the horizontal direction X than the third terminal conductive portion 68.

[0132] Additionally, the main surface-side conductive portion 60A and the back surface-side conductive portion 60B extend so as to connect to the second substrate side surface 51d, the third substrate side surface 51e, and the fourth substrate side surface 51f, respectively. More specifically, the first drive conductive portion 61A, the fourth drive conductive portion 64A, and the control conductive portion 65 are each connected to the third substrate side surface 51e. The first drive conductive portion 61B, the second drive conductive portion 62, and the fourth drive conductive portion 64B are each connected to the fourth substrate side surface 51f. The third drive conductive portion 63 is connected to the second substrate side surface 51d. Furthermore, the first terminal conductive portion 66A, the fourth terminal conductive portion 69A, and the control terminal conductive portion 70 are each connected to the third substrate side surface 51e. The first terminal conductive portion 66B, the second terminal conductive portion 67, and the fourth terminal conductive portion 69B are each connected to the fourth substrate side surface 51f. The third terminal conductive portion 68 is connected to the second substrate side surface 51d.

[0133] Recesses 53A and 53B are provided in the second substrate side surface 51d at portions where the third driving conductive portion 63 and the third terminal conductive portion 68 are arranged. In a plan view, the recesses 53A and 53B are each curvedly recessed from the second substrate side surface 51d toward the first substrate side surface 51c. The recesses 53A and 53B are arranged at intervals in the lateral direction X.

[0134] The third substrate side surface 51e is provided with recesses 54A, 54B, and 54C. In a plan view, the recesses 54A, 54B, and 54C are each curvedly recessed from the third substrate side surface 51e toward the fourth substrate side surface 51f. The recesses 54A, 54B, and 54C are arranged at intervals in the vertical direction Y. The recess 54A is provided in a portion of the substrate 51 where the first drive conductive portion 61A and the first terminal conductive portion 66A are arranged. The recess 54B is provided in a portion of the substrate 51 where the control conductive portion 65 and the control terminal conductive portion 70 are arranged. The recess 54C is provided in a portion of the substrate 51 where the fourth drive conductive portion 64A and the fourth terminal conductive portion 69A are arranged.

[0135] The fourth substrate side surface 51f is provided with recesses 55A, 55B, and 55C. In a plan view, the recesses 55A, 55B, and 55C are each curvedly recessed from the fourth substrate side surface 51f toward the third substrate side surface 51e. The recesses 55A, 55B, and 55C are arranged at intervals in the vertical direction Y. When viewed from the horizontal direction X, the recess 55A is provided at a position overlapping the recess 54A, the recess 55B is provided at a position overlapping the recess 54B, and the recess 55C is provided at a position overlapping the recess 54C. The recess 55A is provided in a portion of the substrate 51 where the first driving conductive portion 61B and the first terminal conductive portion 66B are arranged. The recess 55B is provided in a portion of the substrate 51 where the second driving conductive portion 62 and the second terminal conductive portion 67 are arranged. The recess 55C is provided in a portion of the substrate 51 where the fourth driving conductive portion 64B and the fourth terminal conductive portion 69B are arranged.

[0136] The recesses 53A, 53B, 54A to 54C, and 55A to 55C are each formed from the main surface 51a to the back surface 51b of the substrate 51. The recesses 53A, 53B, 54A to 54C, and 55A to 55C are all equal in shape and size to one another.

[0137] The side surface connecting portion 60D is provided in each of the recesses 53A, 53B, 54A to 54C, and 55A to 55C. The side surface connecting portion 60D is formed along the inner side surface constituting each of the recesses 53A, 53B, 54A to 54C, and 55A to 55C. The side surface connecting portion 60D includes side surface connecting portions 76A to 76H. As shown in FIG. 25, the side surface connecting portions 76C and 76F are each made of a metal film 76a. Although not shown in the drawings, the side surface connecting portions 76A, 76B, 76D, 76E, 76G, and 76H are each made of a metal film 76a, similar to the side surface connecting portions 76C and 76F. An end of the metal film 76a closer to the substrate main surface 51a of the substrate 51 is connected to the main surface-side conductive portion 60A, and an end of the metal film 76a closer to the substrate back surface 51b of the substrate 51 is connected to the back surface-side conductive portion 60B. In this embodiment, the material constituting the metal film 76a is the same as the material constituting the main surface-side conductive portion 60A and the back surface-side conductive portion 60B.

[0138] As shown in FIGS. 23 and 24 , the side surface connecting portion 76A is provided in the recess 53A and connects the third drive conductive portion 63 and the third terminal conductive portion 68. The side surface connecting portion 76B is provided in the recess 53B and connects the third drive conductive portion 63 and the third terminal conductive portion 68. The side surface connecting portion 76C is provided in the recess 54A and connects the first drive conductive portion 61A and the first terminal conductive portion 66A. The side surface connecting portion 76D is provided in the recess 54B and connects the second drive conductive portion 62 and the second terminal conductive portion 67. The side surface connecting portion 76E is provided in the recess 54C and connects the fourth drive conductive portion 64A and the fourth terminal conductive portion 69A. The side surface connecting portion 76F is provided in the recess 55A and connects the first drive conductive portion 61B and the first terminal conductive portion 66B. The side surface connecting portion 76G is provided in the recess 55B and connects the control conductive portion 65 and the control terminal conductive portion 70. The side surface connecting portion 76H is provided in the recess 55C and connects the fourth drive conductive portion 64B and the fourth terminal conductive portion 69B.

[0139] According to this configuration, when the semiconductor laser device 1A is joined to a wiring board or the like by, for example, soldering, a solder fillet is formed on the side surface connecting portion 60D. Therefore, an operator can check the joining state of the semiconductor laser device 1A by visually checking the solder fillet formed on the side surface connecting portion 60D.

[0140] In addition, in the modified semiconductor laser device 1A shown in Figures 23 and 24, the first drive connection parts 73A and 73B (see Figure 3) are omitted by providing side connection parts 76C and 76F, the second drive connection part 74 (see Figure 3) is omitted by providing side connection part 76B, the fourth drive connection parts 76A and 76B (see Figure 3) are omitted by providing side connection parts 76E and 76H, and the control connection part 77 (see Figure 3) is omitted by providing side connection part 76G.

[0141] In addition, at least one of the first drive communication section 73A, 73B, the second drive communication section 74, the fourth drive communication section 76A, 76B, and the control communication section 77 may be added to the modified semiconductor laser device 1A shown in Figures 23 and 24.

[0142] The number of capacitors 30A bonded to the first drive conductive portion 61A and the fourth drive conductive portion 64A, and the number of capacitors 30B bonded to the first drive conductive portion 61B and the fourth drive conductive portion 64B can be changed as desired. A plurality of capacitors 30A and a plurality of capacitors 30B may be provided. The number of capacitors 30A and 30B may be set according to the output of the semiconductor laser element 10, for example.

[0143] [Second embodiment] A semiconductor laser device 1B of the second embodiment will be described with reference to Figures 26 and 27. The semiconductor laser device 1B of the present embodiment is different from the semiconductor laser device 1A of the first embodiment in the configuration of the conductive part 60 and the arrangement of the semiconductor laser element 10, the switching element 20, and the capacitors 30A and 30B. In this embodiment, for convenience, the same components as those in the first embodiment are denoted by the same reference numerals, and their description may be omitted.

[0144] 26, in the semiconductor laser device 1B of this embodiment, the semiconductor laser element 10 and the switching element 20 are not arranged in the center of the support substrate 50 in the lateral direction X, but are arranged closer to the fourth substrate side surface 51f than the center of the support substrate 50 in the lateral direction X. Furthermore, in the semiconductor laser device 1B of this embodiment, the capacitors 30A and 30B are not arranged on both sides of the switching element 20, but are arranged on the third substrate side surface 51e side of the switching element 20 in the lateral direction X. With respect to such an arrangement of the semiconductor laser element 10, the switching element 20, and the capacitors 30A and 30B, the configuration of the conductive section 60 is different from the configuration of the conductive section 60 of the first embodiment.

[0145] Specifically, the main surface side conductive portion 60A has a first drive conductive portion 61, a second drive conductive portion 62, a third drive conductive portion 63, a fourth drive conductive portion 64, and a control conductive portion 65. That is, there is one first drive conductive portion 61 and one fourth drive conductive portion 64.

[0146] The first drive conductive section 61 is arranged in a portion of the substrate 51 closer to the third substrate side surface 51e in the horizontal direction X. The first drive conductive section 61 is arranged in a portion of the substrate 51 closer to the second substrate side surface 51d in the vertical direction Y. In other words, the first drive conductive section 61 is arranged on the substrate 51 so that its center in the vertical direction Y is closer to the second substrate side surface 51d than is the center of the substrate 51 in the vertical direction Y. The shape of the first drive conductive section 61 in a plan view is rectangular with the long side direction being the vertical direction Y and the short side direction being the horizontal direction X.

[0147] The fourth drive conductive portion 64 is disposed in a portion of the substrate 51 closer to the third substrate side surface 51e in the horizontal direction X and closer to the first substrate side surface 51c in the vertical direction Y. In a plan view, the fourth drive conductive portion 64 has a rectangular shape with its longer sides aligned in the horizontal direction X and its shorter sides aligned in the vertical direction Y. When viewed from the vertical direction Y, the fourth drive conductive portion 64 overlaps with the first drive conductive portion 61. The size of the fourth drive conductive portion 64 in the horizontal direction X is greater than the size of the first drive conductive portion 61 in the horizontal direction X.

[0148] Capacitors 30A, 30B are joined to the first drive conductive portion 61 and the fourth drive conductive portion 64 with a conductive bonding material such as Ag paste or solder. The capacitors 30A, 30B are aligned in the vertical direction Y and arranged adjacent to each other with a gap in the horizontal direction X. The first terminals 31 of each of the capacitors 30A, 30B are disposed at an end of the first drive conductive portion 61 closer to the fourth drive conductive portion 64 in the vertical direction Y. The second terminals 32 of each of the capacitors 30A, 30B are disposed at an end of the fourth drive conductive portion 64 closer to the first drive conductive portion 61 in the vertical direction Y.

[0149] The third drive conductive portion 63 is disposed in a portion of the substrate 51 closer to the fourth substrate side surface 51f in the horizontal direction X. The third drive conductive portion 63 is disposed in a portion of the substrate 51 closer to the first substrate side surface 51c in the vertical direction Y. That is, the third drive conductive portion 63 is disposed on the substrate 51 such that its center in the vertical direction Y is located closer to the first substrate side surface 51c than the center of the substrate 51 in the vertical direction Y. The third drive conductive portion 63 can be divided into a switching element mounting portion 63a and a semiconductor laser element mounting portion 63b. The switching element mounting portion 63a and the semiconductor laser element mounting portion 63b are aligned in the vertical direction Y. The semiconductor laser element mounting portion 63b is a portion of the third drive conductive portion 63 closer to the first substrate side surface 51c in the vertical direction Y. In a plan view, the shape of the semiconductor laser element mounting portion 63b is rectangular with its longer side aligned in the horizontal direction X and its shorter side aligned in the vertical direction Y. The switching element mounting portion 63a is closer to the second substrate side surface 51d than the semiconductor laser element mounting portion 63b. In a plan view, the switching element mounting portion 63a has a rectangular shape with its longer sides aligned in the vertical direction Y and its shorter sides aligned in the horizontal direction X. The size of the switching element mounting portion 63a in the horizontal direction X is larger than the size of the semiconductor laser element mounting portion 63b in the horizontal direction X. The semiconductor laser element mounting portion 63b is located closer to the fourth substrate side surface 51f than the switching element mounting portion 63a. For this reason, a notch 63c is formed in the third drive conductive portion 63 adjacent to the semiconductor laser element mounting portion 63b in the horizontal direction X. An end portion of the fourth drive conductive portion 64 closer to the fourth substrate side surface 51f fits into part of the notch 63c.

[0150] The semiconductor laser element 10 is bonded to the semiconductor laser element mounting portion 63b with a conductive bonding material such as Ag paste or solder. The semiconductor laser element 10 is disposed at an end of the semiconductor laser element mounting portion 63b closer to the fourth drive conductive portion 64 in the horizontal direction X. The semiconductor laser element 10 is disposed so that its cathode electrode 12 (not shown in FIG. 26) faces the semiconductor laser element mounting portion 63b. Therefore, the cathode electrode 12 is electrically connected to the semiconductor laser element mounting portion 63b (third drive conductive portion 63) via the conductive bonding material. The anode electrode 11 of the semiconductor laser element 10 faces the opposite side to the third drive conductive portion 63 in the thickness direction Z. The anode electrode 11 and the fourth drive conductive portion 64 are electrically connected by a plurality of (four in this embodiment) laser connecting members 85. The four laser connecting members 85 are arranged at intervals in the vertical direction Y. Each laser connecting member 85 has a first end 85a and a second end 85b. The first end 85a is joined to the anode electrode 11. Specifically, the first end 85a is joined to a central portion of the anode electrode 11 in the horizontal direction X. The second end 85b is joined to the fourth drive conductor 64. Specifically, the second end 85b is joined to an end of the fourth drive conductor 64 closer to the semiconductor laser element mounting portion 63b.

[0151] The switching element 20 is bonded to the switching element mounting portion 63a with a conductive bonding material. The switching element 20 is bonded to the switching element mounting portion 63a with the drain electrode 21 (not shown in FIG. 26) of the switching element 20 facing the third drive conductive portion 63 in the thickness direction Z. Therefore, the drain electrode 21 is electrically connected to the third drive conductive portion 63 via the conductive bonding material. In this way, the drain electrode 21 and the cathode electrode 12 of the semiconductor laser element 10 are electrically connected via the third drive conductive portion 63.

[0152] In the switching element 20 of the present embodiment, the shapes and arrangements of the source electrode 22 and the gate electrode 23 are different from those of the switching element 20 of the first embodiment. In detail, a notch 25 is formed in the source electrode 22 near the second substrate side surface 51d and near the fourth substrate side surface 51f. The gate electrode 23 is formed in the notch 25. In this way, the gate electrode 23 is located at an end of the element main surface 24a of the switching element 20 near the second substrate side surface 51d and near the fourth substrate side surface 51f.

[0153] The second drive conductive portion 62 and the control conductive portion 65 are each arranged closer to the second substrate side surface 51d in the vertical direction Y than the third drive conductive portion 63. The second drive conductive portion 62 and the control conductive portion 65 are each arranged closer to the fourth substrate side surface 51f in the horizontal direction X than the first drive conductive portion 61. The second drive conductive portion 62 and the control conductive portion 65 are aligned in the vertical direction Y and arranged at intervals in the horizontal direction X.

[0154] The source electrode 22 and the first drive conductive portion 61 are electrically connected by a plurality of (three in this embodiment) first drive connecting members 81. The three first drive connecting members 81 are arranged at intervals in the vertical direction Y. The source electrode 22 and the second drive conductive portion 62 are electrically connected by a second drive connecting member 83. The gate electrode 23 and the control conductive portion 65 are electrically connected by a control connecting member 84. The number of first drive connecting members 81 can be changed as desired. For example, the number of first drive connecting members 81 may be set according to the output of the semiconductor laser element 10.

[0155] As shown in FIG. 27, the back surface side conductive portion 60B has first terminal conductive portions 66A, 66B, a second terminal conductive portion 67, a third terminal conductive portion 68A, 68B, a fourth terminal conductive portion 69, and a control terminal conductive portion 70.

[0156] The first terminal conductive portions 66A, 66B are arranged at intervals in the vertical direction Y. The first terminal conductive portions 66A, 66B are arranged at positions overlapping the first drive conductive portion 61 in the thickness direction Z. The first terminal conductive portion 66A has a rectangular shape in plan view, with its long sides extending in the vertical direction Y and its short sides extending in the horizontal direction X. The first terminal conductive portion 66B is arranged closer to the second substrate side surface 51d than the first terminal conductive portion 66A. The first terminal conductive portion 66B has a rectangular shape in plan view, with its long sides extending in the horizontal direction X and its short sides extending in the vertical direction Y. The size of the first terminal conductive portion 66B in the vertical direction Y is smaller than the size of the first terminal conductive portion 66A in the vertical direction Y.

[0157] The second terminal conductive portion 67 is disposed at a position overlapping the second driving conductive portion 62 in the thickness direction Z. The second terminal conductive portion 67 is disposed in alignment with the first terminal conductive portion 66B in the vertical direction Y and spaced apart in the horizontal direction X.

[0158] The third terminal conductive portions 68A, 68B are arranged at intervals in the vertical direction Y. The third terminal conductive portions 68A, 68B are arranged at positions overlapping the third drive conductive portion 63 in the thickness direction Z. The third terminal conductive portion 68A has a rectangular shape in plan view with its long side extending in the vertical direction Y and its short side extending in the horizontal direction X. The third terminal conductive portion 68B has a rectangular shape in plan view with its long side extending in the horizontal direction X and its short side extending in the vertical direction Y. The size of the third terminal conductive portion 68B in the vertical direction Y is smaller than the size of the third terminal conductive portion 68A in the vertical direction Y.

[0159] The fourth terminal conductive portion 69 is aligned with the third terminal conductive portion 68B in the vertical direction Y and is spaced apart in the horizontal direction X. The fourth terminal conductive portion 69 is located closer to the third substrate side surface 51e than the third terminal conductive portion 68B. The fourth terminal conductive portion 69 is aligned with the first terminal conductive portions 66A, 66B in the horizontal direction X and is spaced apart from the first terminal conductive portion 66A in the vertical direction Y. The fourth terminal conductive portion 69 is located closer to the first substrate side surface 51c than the first terminal conductive portion 66A in the vertical direction Y. In the thickness direction Z, the fourth terminal conductive portion 69 is located at a position overlapping with the fourth driving conductive portion 64.

[0160] The control terminal conductive portion 70 is aligned with the second terminal conductive portion 67 in the vertical direction Y and is spaced apart in the horizontal direction X. The control terminal conductive portion 70 is arranged closer to the fourth substrate side surface 51f than the second terminal conductive portion 67 in the horizontal direction X. In the thickness direction Z, the control terminal conductive portion 70 is arranged at a position overlapping with the control conductive portion 65.

[0161] 26 and 27, the communication section 60C has first driving communication sections 73A and 73B, a second driving communication section 74, third driving communication sections 75A and 75B, a fourth driving communication section 76, and a control communication section 77. Each of the communication sections 73A, 73B, 74, 75A, 75B, 76, and 77 has a through hole 71 and a conductor section 72 (not shown in FIGS. 26 and 27), similar to the first embodiment.

[0162] The first drive connecting portion 73A connects the first drive conductive portion 61 and the first terminal conductive portion 66A. The number of first drive connecting portions 73A is not particularly limited, but in this embodiment, four first drive connecting portions 73A are provided.

[0163] The first drive connecting portion 73B connects the first drive conductive portion 61 and the first terminal conductive portion 66B. The number of first drive connecting portions 73B is not particularly limited, but in this embodiment, two first drive connecting portions 73B are provided.

[0164] The second drive connection portion 74 connects the second drive conductive portion 62 and the second terminal conductive portion 67 together. The third drive connecting portion 75A connects the switching element mounting portion 63a of the third drive conductive portion 63 and the third terminal conductive portion 68A. The number of third drive connecting portions 75A is not particularly limited, but in this embodiment, nine third drive connecting portions 75A are provided.

[0165] The third drive connecting portion 75B connects the semiconductor laser element mounting portion 63b of the third drive conductive portion 63 and the third terminal conductive portion 68B. Although the number of third drive connecting portions 75B is not particularly limited, in this embodiment, two third drive connecting portions 75B are provided. One of the third drive connecting portions 75B is provided at a position overlapping the semiconductor laser element 10 in the thickness direction Z.

[0166] (action) Next, the operation of the semiconductor laser device 1B of this embodiment will be described. When the semiconductor laser device 1B is applied to the laser system 100, the positive electrode 111 of the power supply 110 is connected to the fourth drive conductive section 64, and the negative electrode 112 of the power supply 110 is connected to the first drive conductive section 61. The output electrode 141 of the driver circuit 140 is connected to the control conductive section 65, and the input electrode 142 is connected to the second drive conductive section 62. When a current is supplied from the power supply 110 to the semiconductor laser device 1B, the capacitors 30A and 30B are charged when the switching element 20 is in the OFF state, and the charges charged in the capacitors 30A and 30B flow to the semiconductor laser element 10 and the switching element 20 when the switching element 20 is in the ON state. This causes a current to flow through the semiconductor laser element 10 and the switching element 20. Then, a current flows from the source electrode 22 of the switching element 20 to the negative electrode of the power supply 110 via the first drive conductive section 61. More specifically, a drive loop is formed in which a current based on the charges stored in the capacitors 30A and 30B flows through the semiconductor laser element 10 and the switching element 20. Specifically, in the drive loop, a current flows in the following order: the second terminals 32 of the capacitors 30A and 30B, the fourth drive conductive part 64, the laser connecting member 85, the anode electrode 11 and cathode electrode 12 of the semiconductor laser element 10, the third drive conductive part 63, the drain electrode 21 and source electrode 22 of the switching element 20, the first drive connecting member 81, and the first terminals 31 of the capacitors 30A and 30B.

[0167] Meanwhile, voltage Vg is generated between input electrode 142 and output electrode 141 of driver circuit 140, and voltage Vgs, which is a gate-source voltage, is applied to gate electrode 23 of switching element 20. Specifically, a control loop is formed between driver circuit 140 and switching element 20, in which current flows in the following order: output electrode 141 of driver circuit 140, control terminal conductive portion 70, control linking portion 77, control conductive portion 65, control connecting member 84, gate electrode 23, source electrode 22, second drive connecting member 83, second drive conductive portion 62, second drive linking portion 74, second terminal conductive portion 67, and input electrode 142. In this way, input electrode 142 and source electrode 22 are electrically connected independently of the first drive loop and the second drive loop, and therefore voltage Vgs applied to gate electrode 23 is generated based on the potential of source electrode 22 connected to input electrode 142.

[0168] In this way, a current drive loop between the power supply 110 and the semiconductor laser element 10 and the switching element 20, and a current control loop between the driver circuit 140 and the switching element 20 are formed separately, so that the voltage Vg applied to the input electrode 142 of the driver circuit 140 and the voltage Vgs applied to the gate electrode 23 are less likely to be affected by the drive loops. Therefore, the semiconductor laser device 1B of this embodiment can achieve the same effects as those of the first embodiment.

[0169] [Modification of the second embodiment] The semiconductor laser device 1B of the second embodiment can be modified, for example, as follows. The following modifications can be combined as long as no technical contradiction occurs. In the following modifications, parts common to the second embodiment are assigned the same reference numerals as in the second embodiment, and their description will be omitted.

[0170] The second drive conductive portion 62 and the control conductive portion 65 may be interchanged. Accordingly, the second terminal conductive portion 67 and the control terminal conductive portion 70 are also interchanged. Furthermore, the position of the notch 25 of the source electrode 22 of the switching element 20 is changed to be closer to the second substrate side surface 51d and closer to the third substrate side surface 51e of the source electrode 22. In this case, the gate electrode 23 is located closer to the second substrate side surface 51d and closer to the third substrate side surface 51e of the element main surface 24a of the switching element 20.

[0171] Instead of the first terminal conductive portions 66A and 66B, a terminal conductive portion in which the first terminal conductive portion 66A and the first terminal conductive portion 66B are integrated may be formed on the back surface 51b of the substrate. Instead of the third terminal conductive portions 68A and 68B, a terminal conductive portion in which the third terminal conductive portion 68A and the third terminal conductive portion 68B are integrated may be formed on the back surface 51b of the substrate.

[0172] [Third embodiment] 28 and 29, a semiconductor laser device 1C of the third embodiment will be described. The semiconductor laser device 1C of the present embodiment differs from the semiconductor laser device 1B of the second embodiment mainly in the shape of a part of the conductive portion 60 and the arrangement of the electrodes of the switching element 20A. In this embodiment, for convenience, the same components as those in the second embodiment are denoted by the same reference numerals, and their description may be omitted.

[0173] 28, the size in the vertical direction Y of the first drive conductive portion 61 is smaller than the size in the vertical direction Y of the first drive conductive portion 61 of the second embodiment. The second drive conductive portion 62 is arranged to overlap the first drive conductive portion 61 and an end of the third drive conductive portion 63 closer to the first drive conductive portion 61 when viewed in the vertical direction Y. The size in the horizontal direction X of the second drive conductive portion 62 is larger than the size in the horizontal direction X of the second drive conductive portion 62 of the second embodiment. The size in the horizontal direction X of the control conductive portion 65 is larger than the size in the horizontal direction X of the control conductive portion 65 of the second embodiment.

[0174] 29, the second terminal conductive portion 67 is arranged to overlap the first terminal conductive portion 66A and also overlap an end of the third terminal conductive portion 68 closer to the first terminal conductive portion 66A when viewed in the vertical direction Y. The size in the horizontal direction X of the second terminal conductive portion 67 is larger than the size in the horizontal direction X of the second terminal conductive portion 67 of the second embodiment. The size in the horizontal direction X of the control terminal conductive portion 70 is larger than the size in the horizontal direction X of the control terminal conductive portion 70 of the second embodiment.

[0175] 28 and 29, in this embodiment, the first terminal conductive portion 66B and the first drive connecting portion 73B are omitted. Three second drive connecting portions 74 and two control connecting portions 77 are provided. The three second drive connecting portions 74 are aligned in the vertical direction Y and arranged at intervals in the horizontal direction X. The two control connecting portions 77 are aligned in the vertical direction Y and arranged at intervals in the horizontal direction X.

[0176] 28, the switching element 20A is bonded to the switching element mounting portion 63a of the third drive conductive portion 63 with a bonding material. The bonding material in this embodiment is not limited to a conductive bonding material, and an insulating bonding material may also be used. The shape of the switching element 20A in plan view is, for example, a rectangular shape with the longer side extending in the horizontal direction X and the shorter side extending in the vertical direction Y.

[0177] The switching element 20A is a transistor made of, for example, Si (silicon), SiC (silicon carbide), or GaN (gallium nitride). When the switching element 20A is made of SiC, it is suitable for high-speed switching. In this embodiment, the switching element 20A is an N-type MOSFET made of Si.

[0178] The switching element 20A has an element main surface 24a that faces the same direction as the substrate main surface 51a of the base material 51 of the support substrate 50 in the thickness direction Z. A drain electrode 21, a source electrode 22, and a gate electrode 23 are formed on the element main surface 24a. That is, in this embodiment, the drain electrode 21 is not formed on the back surface of the element (not shown). Thus, the switching element 20A of this embodiment is a transistor with a so-called lateral structure.

[0179] The drain electrode 21, the source electrode 22, and the gate electrode 23 are arranged at intervals in the vertical direction Y. The drain electrode 21 is formed on a portion of the element main surface 24a that is closer to the semiconductor laser element 10 in the vertical direction Y. The drain electrode 21 is electrically connected to the third drive conductive portion 63 by a third drive connecting member 88. In this embodiment, three third drive connecting members 88 connect the drain electrode 21 and the third drive conductive portion 63. The three third drive connecting members 88 are arranged at intervals in the horizontal direction X. The third drive connecting member 88 has a first end 88a and a second end 88b.

[0180] A first end 88a of each third drive connecting member 88 is connected to the drain electrode 21. These first end portions 88a are aligned in the vertical direction Y and arranged at intervals in the horizontal direction X. The second end portion 88b of each third drive connecting member 88 is disposed in the vertical direction Y at an end of the switching element mounting portion 63a of the third drive conductive portion 63 that is closer to the semiconductor laser element mounting portion 63b. These second end portions 88b are aligned in the vertical direction Y and arranged at intervals in the horizontal direction X.

[0181] The source electrodes 22 and the gate electrodes 23 are aligned in the vertical direction Y and arranged at intervals in the horizontal direction X. The source electrodes 22 are arranged on the first driving conductive portion 61 side of the gate electrodes 23 in the horizontal direction X.

[0182] The source electrode 22 is electrically connected to the first drive conductive portion 61 by a first drive connecting member 81. In this embodiment, two first drive connecting members 81 connect the source electrode 22 and the first drive conductive portion 61. The source electrode 22 is also electrically connected to the second drive conductive portion 62 by a second drive connecting member 83. In this embodiment, one second drive connecting member 83 connects the source electrode 22 and the second drive conductive portion 62.

[0183] The first end 81a of each of the two first drive connecting members 81 connected to the source electrode 22 is disposed closer to the gate electrode 23 than the first end 83a of the second drive connecting member 83 connected to the source electrode 22. In other words, the first end 83a is disposed closer to the first drive conductive portion 61 (second drive conductive portion 62) than the first end 81a.

[0184] Of the two first drive connecting members 81, the second end 81b connected to the first drive conductive portion 61 is disposed between the first terminal 31 of the capacitors 30A, 30B and the first drive link portion 73 in the vertical direction Y. The second end 83b connected to the second drive conductive portion 62 of the second drive connecting member 83 is disposed at the end of the second drive conductive portion 62 closer to the control conductive portion 65 in the horizontal direction X. As shown in FIG. 28 , the length of the second drive connecting member 83 is shorter than the length of the first drive connecting member 81. Because the second drive connecting member 83 can be formed short, the inductance caused by the second drive connecting member 83 can be reduced. Furthermore, the semiconductor laser device 1C of this embodiment can achieve the same effects as those of the second embodiment.

[0185] [Modification of the third embodiment] The semiconductor laser device 1C of the third embodiment can be modified, for example, as follows. The following modifications can be combined as long as no technical contradiction occurs. In the following modifications, parts common to the first and second embodiments are assigned the same reference numerals as in the first and second embodiments, and their description will be omitted.

[0186] 30, the switching element mounting portion 63a and the semiconductor laser element mounting portion 63b of the third drive conductive portion 63 may be disposed apart from each other in the vertical direction Y. In this case, the second end 88b of the third drive connecting member 88 is disposed on the semiconductor laser element mounting portion 63b. This electrically connects the cathode electrode 12 (not shown in FIG. 30) of the semiconductor laser element 10 and the drain electrode 21 of the switching element 20A.

[0187] The semiconductor laser device 1C of the third embodiment is based on the configuration of the semiconductor laser device 1B of the second embodiment, but the switching element 20 of the semiconductor laser device 1B is replaced with a switching element 20A. However, the present invention is not limited to this. As shown in Fig. 31 , the semiconductor laser device 1C of the third embodiment may be based on the configuration of the semiconductor laser device 1A of the first embodiment, but the switching element 20 of the semiconductor laser device 1A is replaced with a switching element 20A. The switching element 20A of the semiconductor laser device 1C of Fig. 31 has a drain electrode 21, a first source electrode 22A, a second source electrode 22B, and a gate electrode 23 formed on the device main surface 24a.

[0188] The drain electrode 21, the first source electrode 22A, the second source electrode 22B, and the gate electrode 23 are arranged at intervals in the vertical direction Y. The drain electrode 21 is formed on a portion of the element main surface 24a closer to the semiconductor laser element 10 in the vertical direction Y. The drain electrode 21 is electrically connected to the third drive conductive portion 63 by a third drive connecting member 88. In FIG. 31 , three third drive connecting members 88 connect the drain electrode 21 and the third drive conductive portion 63. The three third drive connecting members 88 are arranged at intervals in the horizontal direction X. A first end 88a of each third drive connecting member 88 is connected to the drain electrode 21. These first ends 88a are arranged at intervals in the horizontal direction X while being aligned in the vertical direction Y. The second end 88b of each third drive connecting member 88 is disposed in the vertical direction Y at an end of the switching element mounting portion 63a of the third drive conductive portion 63 that is closer to the semiconductor laser element mounting portion 63b. These second end portions 88b are aligned in the vertical direction Y and arranged at intervals in the horizontal direction X.

[0189] The first source electrode 22A, the second source electrode 22B, and the gate electrode 23 are aligned in the vertical direction Y and arranged at intervals in the horizontal direction X. The gate electrode 23 is disposed between the first source electrode 22A and the second source electrode 22B in the horizontal direction X. The first source electrode 22A is disposed on the first driving conductive section 61A side of the gate electrode 23. The second source electrode 22B is disposed on the first driving conductive section 61B side of the gate electrode 23.

[0190] The first source electrode 22A is electrically connected to the first drive conductive portion 61A by a first drive connecting member 81. The second source electrode 22B is electrically connected to the first drive conductive portion 61B by a first drive connecting member 82 and is electrically connected to the second drive conductive portion 62 by a second drive connecting member 83. A second end 83b of the second drive connecting member 83 is disposed in a portion of the second drive conductive portion 62 that overlaps with the second source electrode 22B when viewed from the vertical direction Y. This allows the length of the second drive connecting member 83 to be shortened. The gate electrode 23 is connected to the control conductive portion 65 by a control connecting member 84. Even with this configuration, the first drive connecting members 81, 82 and the second drive connecting member 83 are formed separately, thereby achieving the same effects as those of the first embodiment.

[0191] In the semiconductor laser device 1C of Fig. 31, the configuration of the source electrodes of the switching element 20A can be changed to the configuration of the source electrodes of the switching element 20A shown in Fig. 32. Specifically, the switching element 20A of the semiconductor laser device 1C of Fig. 32 has a first source electrode 22A, a second source electrode 22B, and a third source electrode 22C as source electrodes. The source electrodes 22A to 22C and the gate electrodes 23 are arranged at an end of the element main surface 24a of the switching element 20A in the vertical direction Y that is closer to the second substrate side surface 51d. The source electrodes 22A to 22C and the gate electrodes 23 are arranged at intervals in the horizontal direction X while being aligned in the vertical direction Y.

[0192] The first source electrode 22A is arranged closer to the first driving conductive unit 61A in the horizontal direction X than the source electrodes 22B and 22C and the gate electrode 23. The second source electrode 22B is arranged closer to the first driving conductive unit 61B in the horizontal direction X than the source electrodes 22A and 22C and the gate electrode 23. In this way, the third source electrode 22C and the gate electrode 23 are arranged between the first source electrode 22A and the second source electrode 22B in the horizontal direction X. The third source electrode 22C is arranged on the second source electrode 22B side with respect to the gate electrode 23.

[0193] The first source electrode 22A is connected to the first drive conductive portion 61A by a first drive connection member 81. The second source electrode 22B is connected to the first drive conductive portion 61B by a first drive connection member 82. The third source electrode 22C is connected to the second drive conductive portion 62 by a second drive connection member 83. A second end 83b of the second drive connection member 83 is disposed at an end of the second drive conductive portion 62 closer to the control conductive portion 65 in the horizontal direction X. This brings the third source electrode 22C and the second end 83b closer to each other in the horizontal direction X, thereby enabling the length of the second drive connection member 83 to be shortened. The gate electrode 23 is connected to the control conductive portion 65 by a control connection member 84. A second end 84b of the control connection member 84 is connected to an end of the control conductive portion 65 closer to the second drive conductive portion 62 in the horizontal direction X. This brings the gate electrode 23 and the second end 84b closer to each other in the lateral direction X, thereby shortening the length of the control connecting member 84. The semiconductor laser device 1C in FIG. 32 provides the same effects as those of the first embodiment.

[0194] 31 and 32, the shape of the third drive conductive portion 63 can be changed as desired. In one example, the switching element mounting portion 63a and the semiconductor laser element mounting portion 63b of the third drive conductive portion 63 may be spaced apart in the vertical direction Y. In this case, the second end 88b of the third drive connecting member 88 is disposed on the semiconductor laser element mounting portion 63b. This electrically connects the cathode electrode 12 of the semiconductor laser element 10 and the drain electrode 21 of the switching element 20A.

[0195] [Fourth embodiment] A semiconductor laser device 1D of the fourth embodiment will be described with reference to Figures 33 and 34. The semiconductor laser device 1D of this embodiment differs from the semiconductor laser device 1A of the first embodiment in that it includes a built-in driver circuit 140. In this embodiment, for convenience, the same components as those in the first embodiment are denoted by the same reference numerals, and their description may be omitted.

[0196] 33, the base material 51 of the support substrate 50 of this embodiment has a rectangular shape in plan view with its longer sides aligned in the vertical direction Y and its shorter sides aligned in the horizontal direction X. In this embodiment, the first drive conductive portions 61A, 61B and the third drive conductive portion 63 are disposed closer to the first substrate side surface 51c of the base material 51 in the vertical direction Y. That is, the centers of the first drive conductive portions 61A, 61B and the third drive conductive portion 63 in the vertical direction Y are located closer to the first substrate side surface 51c than the center of the base material 51 in the vertical direction Y. In this embodiment, the conductive portion 60 is configured such that the second drive conductive portion 62 and the control conductive portion 65 (both see FIG. 2) are omitted from the main surface-side conductive portion 60A, and the second terminal conductive portion 67 and the control terminal conductive portion 70 (both see FIG. 3) are omitted from the back surface-side conductive portion 60B.

[0197] In a portion of the substrate main surface 51a of the substrate 51 that is closer to the second substrate side surface 51d than the first driving conductive portions 61A, 61B and the third driving conductive portion 63, a driver circuit mounting portion 150, a first power supply conductive portion 151, a second power supply conductive portion 152, a signal conductive portion 153, and a reference voltage conductive portion 154 are formed as the main surface side conductive portion 60A.

[0198] The driver circuit mounting section 150 is disposed at a position overlapping the third driving conductive section 63 when viewed from the vertical direction Y. The driver circuit mounting section 150 has a rectangular shape in plan view with its longer side aligned in the horizontal direction X and its shorter side aligned in the vertical direction Y. A first power supply conductive section 151, a second power supply conductive section 152, a signal conductive section 153, and a reference voltage conductive section 154 are disposed on both sides of the driver circuit mounting section 150 in the horizontal direction X. More specifically, the first power supply conductive section 151 and the second power supply conductive section 152 are disposed on the third substrate side surface 51e side of the driver circuit mounting section 150 in the horizontal direction X, and the signal conductive section 153 and the reference voltage conductive section 154 are disposed on the fourth substrate side surface 51f side of the driver circuit mounting section 150.

[0199] The first power supply conductive portion 151 and the second power supply conductive portion 152 are aligned in the horizontal direction X and arranged at intervals in the vertical direction Y. When viewed from the vertical direction Y, the first power supply conductive portion 151 and the second power supply conductive portion 152 are each arranged at a position overlapping the first drive conductive portion 61A. The first power supply conductive portion 151 is arranged on the first drive conductive portion 61A side in the vertical direction Y with respect to the second power supply conductive portion 152.

[0200] The signal conductive portions 153 and the reference voltage conductive portions 154 are aligned in the horizontal direction X and arranged at intervals in the vertical direction Y. When viewed in the vertical direction Y, the signal conductive portions 153 and the reference voltage conductive portions 154 are aligned in the horizontal direction X and arranged at intervals in the vertical direction Y. When viewed in the vertical direction Y, the signal conductive portions 153 and the reference voltage conductive portions 154 are each arranged at a position overlapping with the first drive conductive portion 61B. The signal conductive portion 153 is arranged on the first drive conductive portion 61B side with respect to the reference voltage conductive portion 154 in the vertical direction Y.

[0201] The first power supply conductive portion 151, the second power supply conductive portion 152, the signal conductive portion 153, and the reference voltage conductive portion 154 each have a square shape in plan view. The shapes of the first power supply conductive portion 151, the second power supply conductive portion 152, the signal conductive portion 153, and the reference voltage conductive portion 154 in plan view can be arbitrarily changed. For example, the shapes of the first power supply conductive portion 151, the second power supply conductive portion 152, the signal conductive portion 153, and the reference voltage conductive portion 154 in plan view may be rectangular with one of the vertical direction Y and the horizontal direction X as the long side direction and the other of the vertical direction Y and the horizontal direction X as the short side direction. At least one of the shapes of the first power supply conductive portion 151, the second power supply conductive portion 152, the signal conductive portion 153, and the reference voltage conductive portion 154 in plan view may be different from the other shapes.

[0202] The driver circuit 140 is mounted on the driver circuit mounting section 150. In this embodiment, the driver circuit 140 is configured as a chip in which electronic components such as transistors that make up the driver circuit 140 are sealed with a sealing member 143. In this embodiment, the sealing member 143 is configured to cover the entire electronic components with a resin material, but the specific configuration of the sealing member 143 is not particularly limited. The shape of the driver circuit 140 in a plan view is rectangular, with the horizontal direction X as the long side direction and the vertical direction Y as the short side direction.

[0203] The sealing member 143 has a sealing principal surface 143a and a sealing rear surface (not shown) facing opposite directions in the thickness direction Z. The sealing principal surface 143a faces the same direction in the thickness direction Z as the element principal surface 24a of the switching element 20. The sealing rear surface faces the same direction in the thickness direction Z as the element rear surface 24b of the switching element 20. A plurality of electrodes 144 are exposed on the sealing principal surface 143a. The plurality of electrodes 144 include a first power electrode 144a, a second power electrode 144b, an output electrode 144c, an input electrode 144d, a signal electrode 144e, and a reference voltage output electrode 144f.

[0204] The first power supply electrode 144a is an electrode electrically connected to the positive electrode of a control power supply (not shown), and is an electrode to which, for example, a first power supply voltage (Vcc) is applied. The first power supply electrode 144a is arranged at an end of the sealing main surface 143a closer to the third substrate side surface 51e in the horizontal direction X and at an end of the sealing main surface 143a closer to the switching element 20 in the vertical direction Y.

[0205] The second power supply electrode 144b is an electrode electrically connected to the negative pole of the control power supply, and is, for example, an electrode to which a second power supply voltage (GND) lower than the first power supply voltage (Vcc) is applied. The second power supply electrode 144b is arranged at an end of the sealing principal surface 143a closer to the third substrate side surface 51e in the horizontal direction X and at an end of the sealing principal surface 143a closer to the second substrate side surface 51d in the vertical direction Y.

[0206] The output electrode 144c is an electrode for applying a gate voltage to the gate electrode 23 of the switching element 20. The output electrode 144c is arranged in the center of the sealing main surface 143a in the horizontal direction X and at an end of the sealing main surface 143a in the vertical direction Y that is closer to the switching element 20. When viewed from the vertical direction Y, the output electrode 144c is arranged at a position overlapping with the gate electrode 23 of the switching element 20.

[0207] The input electrode 144d is an electrode for electrically connecting to the source electrode 22 of the switching element 20. The input electrode 144d is arranged at an end of the sealing principal surface 143a closer to the fourth substrate side surface 51f in the horizontal direction X, and at an end of the sealing principal surface 143a closer to the switching element 20 in the vertical direction Y. When viewed from the vertical direction Y, the input electrode 144d is arranged at a position overlapping with the source electrode 22 of the switching element 20.

[0208] The signal electrode 144e is an electrode to which a gate signal is input from a gate signal generating circuit (not shown) provided outside the semiconductor laser device 1D. The signal electrode 144e is arranged at an end of the encapsulating main surface 143a closer to the fourth substrate side surface 51f in the horizontal direction X and at the center of the encapsulating main surface 143a in the vertical direction Y.

[0209] The reference voltage output electrode 144f is an electrode for transforming a first power supply voltage applied from, for example, a control power supply into a reference voltage (for example, 2.5 V) and outputting the reference voltage. In this case, a regulator for generating the reference voltage is provided inside the driver circuit 140. The reference voltage output electrode 144f is disposed at an end of the sealing main surface 143a closer to the fourth substrate side surface 51f in the horizontal direction X and at an end of the sealing main surface 143a closer to the second substrate side surface 51d in the vertical direction Y.

[0210] The driver circuit 140 is electrically connected to the switching elements 20 and the main surface side conductive portions 60A by a plurality of driver connection members 160. The plurality of driver connection members 160 includes a first driver connection member 161, a second driver connection member 162, a third driver connection member 163, a fourth driver connection member 164, a fifth driver connection member 165, and a sixth driver connection member 166. These driver connection members 161 to 165 are made of, for example, the same material as the first driver connection members 81 and 82 and the laser connection members 85 and 86. Each of the driver connection members 161 to 165 is a wire made of a metal such as Au (gold), Cu (copper), or Al (aluminum). In this embodiment, each of the driver connection members 161 to 165 is formed by wire bonding. The wire diameter of each of the driver connecting members 161-165 is equal to the wire diameter of the first drive connecting members 81, 82 and the laser connecting members 85, 86. Here, if the maximum deviation between the wire diameter of each of the driver connecting members 161-165 and the wire diameter of the first drive connecting members 81, 82 and the laser connecting members 85, 86 is, for example, within 5% of the wire diameter of the first drive connecting member 81, then it can be said that the wire diameter of each of the driver connecting members 161-165 is equal to the wire diameter of the first drive connecting members 81, 82 and the laser connecting members 85, 86.

[0211] The first driver connecting member 161 connects the first power supply electrode 144a and the first power supply conductive portion 151. The second driver connecting member 162 connects the second power supply electrode 144b and the second power supply conductive portion 152. The third driver connecting member 163 connects the signal electrode 144e and the signal conductive portion 153. The fourth driver connecting member 164 connects the reference voltage output electrode 144f and the reference voltage conductive portion 154. The fifth driver connecting member 165 connects the output electrode 144c and the gate electrode 23 of the switching element 20. Therefore, the fifth driver connecting member 165 corresponds to a control connecting member that connects the driver circuit and the control electrode of the switching element. The sixth driver connecting member 166 connects the input electrode 144d and the source electrode 22 of the switching element 20. Therefore, the sixth driver connecting member 166 corresponds to a second drive connecting member that connects the driver circuit and the second drive electrode of the switching element. The sixth driver connecting member 166 has a first end 166a and a second end 166b. The first end 166a is connected to the source electrode 22, and the second end 166b is connected to the input electrode 144d. The first end 166a is connected to a portion of the source electrode 22 that overlaps with the input electrode 144d when viewed in the vertical direction Y, and is connected to an end of the source electrode 22 closer to the input electrode 144d in the vertical direction Y.

[0212] As shown in FIG. 34, the back surface-side conductive portion 60B has a conductive portion 155 for the driver terminal, a conductive portion 156 for the first power supply terminal, a conductive portion 157 for the second power supply terminal, a conductive portion 158 for the signal terminal, and a conductive portion 159 for the reference voltage terminal.

[0213] As shown in FIGS. 33 and 34 , the driver terminal conductive portion 155 is disposed on the back surface 51b of the substrate 51 at a portion overlapping the driver circuit mounting portion 150 when viewed from the thickness direction Z. The shape and size of the driver terminal conductive portion 155 are the same as those of the driver circuit mounting portion 150. The first power supply terminal conductive portion 156 is disposed on the back surface 51b of the substrate at a portion overlapping the first power supply conductive portion 151 when viewed from the thickness direction Z. The shape and size of the first power supply terminal conductive portion 156 are the same as those of the first power supply conductive portion 151. The second power supply terminal conductive portion 157 is disposed on the back surface 51b of the substrate at a portion overlapping the second power supply conductive portion 152 when viewed from the thickness direction Z. The shape and size of the second power supply terminal conductive portion 157 are the same as those of the second power supply conductive portion 152. The signal terminal conductive portion 158 is arranged in a portion of the back surface 51b of the substrate that overlaps with the signal conductive portion 153 when viewed from the thickness direction Z. The shape and size of the signal terminal conductive portion 158 are the same as those of the signal conductive portion 153. The reference voltage terminal conductive portion 159 is arranged in a portion of the back surface 51b of the substrate that overlaps with the reference voltage conductive portion 154 when viewed from the thickness direction Z. The shape and size of the reference voltage terminal conductive portion 159 are the same as those of the reference voltage conductive portion 154.

[0214] 34 , the size of gap Gr7 between driver terminal conductive portion 155 and each power supply terminal conductive portion 156, 157 in the horizontal direction X is smaller than the size of gap Gr2 between third terminal conductive portion 68 and first terminal conductive portion 66A in the horizontal direction X. Furthermore, the size of gap Gr8 between driver terminal conductive portion 155 and signal terminal conductive portion 158 and reference voltage terminal conductive portion 159 in the horizontal direction X is smaller than the size of gap Gr2 between third terminal conductive portion 68 and first terminal conductive portion 66B in the horizontal direction X. Furthermore, the sizes of gap Gr7 and gap Gr8 are each smaller than the size of gap Gr9 between driver terminal conductive portion 155 and third terminal conductive portion 68 in the vertical direction Y.

[0215] 33 and 34, the connection portion 60C has a plurality (four in this embodiment) of driver connection portions 170, a first power supply connection portion 171, a second power supply connection portion 172, a signal connection portion 173, and a reference voltage connection portion 174. These connection portions 170 to 174, like the other connection portions, have through holes 71 and conductor portions 72 (both not shown in FIGS. 33 and 34).

[0216] The four driver connecting portions 170 are provided in portions of the base material 51 that overlap the driver circuit mounting portion 150 and the driver terminal conductive portion 155 in the thickness direction Z. Each driver connecting portion 170 connects the driver circuit mounting portion 150 and the driver terminal conductive portion 155.

[0217] The first power supply connecting portion 171 is provided in a portion of the base material 51 that overlaps the first power supply conductive portion 151 and the first power supply terminal conductive portion 156 in the thickness direction Z. The first power supply connecting portion 171 connects the first power supply conductive portion 151 and the first power supply terminal conductive portion 156.

[0218] The second power supply connecting portion 172 is provided in a portion of the base material 51 that overlaps the second power supply conductive portion 152 and the second power supply terminal conductive portion 157 in the thickness direction Z. The second power supply connecting portion 172 connects the second power supply conductive portion 152 and the second power supply terminal conductive portion 157.

[0219] The signal connecting portion 173 is provided in a portion of the substrate 51 that overlaps the signal conductive portion 153 and the signal terminal conductive portion 158 in the thickness direction Z. The signal connecting portion 173 connects the signal conductive portion 153 and the signal terminal conductive portion 158.

[0220] The reference voltage connecting portion 174 is provided in a portion of the substrate 51 that overlaps the reference voltage conductive portion 154 and the reference voltage terminal conductive portion 159 in the thickness direction Z. The reference voltage connecting portion 174 connects the reference voltage conductive portion 154 and the reference voltage terminal conductive portion 159.

[0221] The number of these connecting portions 170 to 174 can be changed arbitrarily. The semiconductor laser device 1D only needs to have at least one of each of these connecting portions 170 to 174. The position of the driver connecting portion 170 relative to the driver circuit mounting portion 150 (driver terminal conductive portion 155), the position of the first power supply connecting portion 171 relative to the first power supply conductive portion 151 (first power supply terminal conductive portion 156), the position of the second power supply connecting portion 172 relative to the second power supply conductive portion 152 (second power supply terminal conductive portion 157), the position of the signal connecting portion 173 relative to the signal conductive portion 153 (signal terminal conductive portion 158), and the position of the reference voltage connecting portion 174 relative to the reference voltage conductive portion 154 (reference voltage terminal conductive portion 159) can each be changed arbitrarily.

[0222] According to the semiconductor laser device 1D of this embodiment, in addition to the effects of the first embodiment, the following effects can be obtained. (4-1) The semiconductor laser device 1D includes a driver circuit 140. With this configuration, a first drive loop and a second drive loop are formed as a first path for a current flowing from the source electrode 22 of the switching element 20 to the first drive conductive parts 61A and 61B via the first drive connecting members 81 and 82, and a control loop is formed as a second path for a current flowing from the source electrode 22 to the driver circuit 140 via the sixth driver connecting member 166. This reduces the influence of fluctuations in the currents in the first drive loop and the second drive loop on the control loop. That is, the control loop is less susceptible to the influence of the inductance of the first drive connecting members 81 and 82. Therefore, in the control loop, the influence of the back electromotive force caused by the inductance of the first drive connecting members 81 and 82 on the voltage Vgs applied to the gate electrode 23 of the switching element 20 can be reduced.

[0223] In addition, since the driver circuit 140 is built into the semiconductor laser device 1D, the distance between the source electrode 22 of the switching element 20 and the input electrode 142 of the driver circuit 140, and the distance between the gate electrode 23 of the switching element 20 and the output electrode 141 of the driver circuit 140 are shortened, thereby reducing the inductance in the control loop.

[0224] (4-2) The driver circuit 140 is disposed on the opposite side of the switching element 20 from the semiconductor laser element 10 in the vertical direction Y. With this configuration, the control loop can be formed farther away from the first drive loop and the second drive loop, making the control loop less susceptible to the influence of the inductance of the first drive loop and the second drive loop.

[0225] (4-3) The gate electrode 23 of the switching element 20 is disposed closer to the driver circuit 140. This configuration shortens the distance between the gate electrode 23 and the output electrode 141 of the driver circuit 140. This reduces the inductance in the control loop.

[0226] (4-4) The sixth driver connecting member 166 is connected to the end of the source electrode 22 of the switching element 20 that is closer to the driver circuit 140 in the vertical direction Y. With this configuration, the length of the sixth driver connecting member 166 can be shortened, thereby reducing the inductance in the control loop.

[0227] [Modification of the fourth embodiment] The semiconductor laser device 1D of the fourth embodiment can be modified, for example, as follows. The following modifications can be combined as long as no technical contradiction occurs. In the following modifications, parts common to the first to fourth embodiments are assigned the same reference numerals as in the first to fourth embodiments, and their description will be omitted.

[0228] The semiconductor laser device 1D of the fourth embodiment is based on the configuration of the semiconductor laser device 1A of the first embodiment and has a built-in driver circuit 140 in the semiconductor laser device 1A, but is not limited to this. For example, the semiconductor laser device 1D may be based on the configuration of the semiconductor laser device 1B of the second embodiment or the semiconductor laser device 1C of the third embodiment and has a built-in driver circuit 140 in the semiconductor laser device 1B, 1C.

[0229] 35 and 36 show a first example of the configuration of a semiconductor laser device 1D in which a driver circuit 140 is built into the semiconductor laser device 1B of the second embodiment. As shown in FIG. 35, the base 51 of the support substrate 50 of this embodiment has a rectangular shape in plan view, with its longer sides aligned in the vertical direction Y and its shorter sides aligned in the horizontal direction X. In this embodiment, the first drive conductive portion 61 and the third drive conductive portion 63 are disposed closer to the first substrate side surface 51c of the base 51 in the vertical direction Y. That is, the centers of the first drive conductive portion 61 and the third drive conductive portion 63 in the vertical direction Y are located closer to the first substrate side surface 51c than the center of the base 51 in the vertical direction Y. In addition, in this embodiment, the conductive portion 60 is configured such that the second drive conductive portion 62 and the control conductive portion 65 are omitted from the main surface-side conductive portion 60A, and the second terminal conductive portion 67 and the control terminal conductive portion 70 (both of which are shown in FIG. 3) are omitted from the back surface-side conductive portion 60B.

[0230] A driver circuit mounting section 150, a first power supply conductive section 151, a second power supply conductive section 152, a signal conductive section 153, and a reference voltage conductive section 154 are formed on a portion of the substrate main surface 51a of the substrate 51 that is closer to the second substrate side surface 51d than the first drive conductive section 61 and the third drive conductive section 63. The shape and arrangement of the driver circuit mounting section 150 and each of the conductive sections 151 to 154 are the same as those of the driver circuit mounting section 150 and each of the conductive sections 151 to 154 in the fourth embodiment, and therefore description thereof will be omitted.

[0231] The driver circuit 140 mounted on the driver circuit mounting portion 150 differs from the driver circuit 140 of the fourth embodiment only in the arrangement of the output electrode 144c and the input electrode 144d. The output electrode 144c is arranged at an end of the sealing main surface 143a of the sealing member 143 closer to the fourth substrate side surface 51f in the horizontal direction X and at an end of the sealing main surface 143a closer to the switching element 20 in the vertical direction Y. When viewed from the vertical direction Y, the output electrode 144c is arranged at a position overlapping with the source electrode 22 of the switching element 20. The output electrode 144c is arranged closer to the third substrate side surface 51e than the gate electrode 23 of the switching element 20. The input electrode 144d is arranged at a portion of the sealing main surface 143a closer to the fourth substrate side surface 51f than the center of the sealing main surface 143a in the horizontal direction X and at an end of the sealing main surface 143a closer to the switching element 20 in the vertical direction Y. The distance between the input electrode 144d and the output electrode 144c in the horizontal direction X is smaller than the distance between the input electrode 144d and the first power electrode 144a in the horizontal direction X. When viewed from the vertical direction Y, the input electrode 144d is disposed so that a portion thereof overlaps with the source electrode 22.

[0232] The connection manner of the first to fourth driver connecting members 161 to 164 is the same as the connection manner of the first to fourth driver connecting members 161 to 164 in the fourth embodiment. The fifth driver connecting member 165 connects the output electrode 144c and the gate electrode 23. Therefore, in a plan view, the fifth driver connecting member 165 extends obliquely toward the fourth substrate side surface 51f from the output electrode 144c toward the gate electrode 23. The sixth driver connecting member 166 connects the input electrode 144d and the source electrode 22. The sixth driver connecting member 166 is connected to the end of the source electrode 22 closer to the driver circuit 140 in the vertical direction Y. As shown in FIG. 35 , the length of the sixth driver connecting member 166 is shorter than the length of the fifth driver connecting member 165.

[0233] 36, the back-surface-side conductive portion 60B has a first terminal conductive portion 66, a third terminal conductive portion 68, a fourth terminal conductive portion 69, a driver terminal conductive portion 155, a first power supply terminal conductive portion 156, a second power supply terminal conductive portion 157, a signal terminal conductive portion 158, and a reference voltage terminal conductive portion 159. Note that the configurations and arrangements of the driver terminal conductive portion 155, the first power supply terminal conductive portion 156, the second power supply terminal conductive portion 157, the signal terminal conductive portion 158, and the reference voltage terminal conductive portion 159 are the same as those in the fourth embodiment, and therefore will not be described.

[0234] The first terminal conductive portion 66 is disposed on the rear surface 51b of the substrate at a portion that overlaps with the first drive conductive portion 61 in the thickness direction Z. The size of the first terminal conductive portion 66 in the vertical direction Y is smaller than the size of the first drive conductive portion 61 in the vertical direction Y.

[0235] The fourth terminal conductive portion 69 is disposed on the rear surface 51b of the substrate at a portion overlapping the fourth drive conductive portion 64 in the thickness direction Z. The fourth terminal conductive portion 69 is disposed at a position overlapping the first terminal conductive portion 66 when viewed in the vertical direction. The size of the fourth terminal conductive portion 69 in the horizontal direction X is smaller than the size of the fourth drive conductive portion 64 in the horizontal direction X.

[0236] The third terminal conductive portion 68 is disposed on the back surface 51b of the substrate at a portion overlapping the third drive conductive portion 63 in the thickness direction Z. The size of the third terminal conductive portion 68 in the lateral direction X is smaller than the size of the third drive conductive portion 63 in the lateral direction X. The third terminal conductive portion 68 of this embodiment is formed by integrating the third terminal conductive portions 68A, 68B of the semiconductor laser device 1B of the second embodiment.

[0237] 35 and 36, the connection section 60C has a first drive connection section 73, third drive connection sections 75A and 75B, a fourth drive connection section 76, a driver connection section 170, a first power supply connection section 171, a second power supply connection section 172, a signal connection section 173, and a reference voltage connection section 174. The configurations and arrangements of the driver connection section 170, the first power supply connection section 171, the second power supply connection section 172, the signal connection section 173, and the reference voltage connection section 174 are the same as those in the fourth embodiment, and therefore will not be described.

[0238] The first drive connecting portions 73 connect the first drive conductive portions 61 and the first terminal conductive portions 66. In Figures 35 and 36, four first drive connecting portions 73 are arranged on the second substrate side surface 51d side of the first drive conductive portions 61 and the first terminal conductive portions 66 in the vertical direction Y.

[0239] The third drive connecting portion 75A is provided on the switching element mounting portion 63a. The third drive connecting portion 75B is provided on the semiconductor laser element mounting portion 63b. In this embodiment, nine third drive connecting portions 75A and two third drive connecting portions 75B are provided. Each third drive connecting portion 75A connects the switching element mounting portion 63a and the third terminal conductive portion 68. Each third drive connecting portion 75B connects the semiconductor laser element mounting portion 63b and the third terminal conductive portion 68. In this way, by incorporating the driver circuit 140, the same effects as those of the fourth embodiment can be obtained.

[0240] Fig. 37 shows a configuration in which the electrodes formed on the element main surface 24a of the switching element 20 are different from those of the semiconductor laser device 1D of Fig. 35. A first source electrode 22A, a second source electrode 22B, and a gate electrode 23 are formed on the element main surface 24a of the switching element 20 of Fig. 37.

[0241] The first source electrode 22A is formed over most of the element principal surface 24a. A notch 25 is formed in the first source electrode 22A. The notch 25 is formed at an end of the first source electrode 22A closer to the driver circuit 140 in the vertical direction Y and at a portion closer to the first driving conductor 61 in the horizontal direction X. The second source electrode 22B and the gate electrode 23 are arranged in the notch 25.

[0242] The second source electrode 22B and the gate electrode 23 are aligned in the vertical direction Y and spaced apart in the horizontal direction X. The second source electrode 22B is disposed on the first driving conductive portion 61 side of the gate electrode 23 in the horizontal direction X. The second source electrode 22B is disposed in a position where a portion of it overlaps with the input electrode 144d when viewed from the vertical direction Y. The gate electrode 23 is disposed in a position where a portion of it overlaps with the output electrode 144c when viewed from the vertical direction Y. This configuration can shorten the length of the fifth driver connecting member 165 connecting the gate electrode 23 and the output electrode 144c, and the length of the sixth driver connecting member 166 connecting the second source electrode 22B and the input electrode 144d.

[0243] 38 and 39 show a second example of the configuration of a semiconductor laser device 1D in which a driver circuit 140 is built into the semiconductor laser device 1B of the second embodiment. As shown in FIG. 38, the shape of the base material 51 of the support substrate 50 in this embodiment in a plan view is rectangular, with the longer side direction being the horizontal direction X and the shorter side direction being the vertical direction Y. In this embodiment, the distance in the horizontal direction X between the third drive conductive portion 63 and the third base side surface 51e of the base material 51 is larger than in the fourth embodiment. In addition, in this embodiment, the conductive portion 60 is configured such that the second drive conductive portion 62 and the control conductive portion 65 are omitted from the main surface-side conductive portion 60A, and the second terminal conductive portion 67 and the control terminal conductive portion 70 (both see FIG. 34) are omitted from the back surface-side conductive portion 60B.

[0244] The third drive conductive portion 63 is disposed in the center of the substrate main surface 51a in the horizontal direction X. The driver circuit mounting portion 150, the first power supply conductive portion 151, the second power supply conductive portion 152, the signal conductive portion 153, and the reference voltage conductive portion 154 are each disposed on the opposite side of the third drive conductive portion 63 from the first drive conductive portion 61 in the horizontal direction X (the fourth substrate side surface 51f side). The shape of the driver circuit mounting portion 150 in a plan view is rectangular with the longer side extending in the vertical direction Y and the shorter side extending in the horizontal direction X.

[0245] The first power supply conductive portion 151 and the second power supply conductive portion 152 are each arranged closer to the first substrate side surface 51c than the driver circuit mounting portion 150 in the vertical direction Y. The first power supply conductive portion 151 and the second power supply conductive portion 152 are arranged at intervals in the horizontal direction X while being aligned in the vertical direction Y. When viewed from the vertical direction Y, the first power supply conductive portion 151 and the second power supply conductive portion 152 are each arranged at a position overlapping the driver circuit mounting portion 150. The first power supply conductive portion 151 is arranged on the third drive conductive portion 63 side relative to the second power supply conductive portion 152 in the horizontal direction X.

[0246] The signal conductive portion 153 and the reference voltage conductive portion 154 are each arranged closer to the second substrate side surface 51d than the driver circuit mounting portion 150 in the vertical direction Y. The signal conductive portion 153 and the reference voltage conductive portion 154 are arranged in the horizontal direction X while being aligned in the vertical direction Y. When viewed from the vertical direction Y, the signal conductive portion 153 and the reference voltage conductive portion 154 are each arranged in a position overlapping with the driver circuit mounting portion 150. The signal conductive portion 153 is arranged on the third drive conductive portion 63 side relative to the reference voltage conductive portion 154 in the horizontal direction X.

[0247] The driver circuit 140 is mounted on the driver circuit mounting section 150. The driver circuit 140 in FIG. 38 is arranged in a different direction on the driver circuit mounting section 150 than the driver circuit 140 in FIG. 35. Specifically, the driver circuit 140 in FIG. 38 is arranged by rotating the driver circuit 140 in FIG. 35 by 90 degrees clockwise when viewed from a direction perpendicular to the substrate main surface 51a. Therefore, the connection mode of each of the driver connecting members 161 to 165 is generally the same as the connection mode of each of the driver connecting members 161 to 165 in FIG. 35. A first end 166a of the sixth driver connecting member 166 is connected to an end of the source electrode 22 closer to the input electrode 144d in the horizontal direction X.

[0248] As shown in FIG. 39, in the horizontal direction X, a conductive portion 155 for the driver terminal, a conductive portion 156 for the first power supply terminal, a conductive portion 157 for the second power supply terminal, a conductive portion 158 for the signal terminal, and a conductive portion 159 for the reference voltage terminal are arranged closer to the fourth substrate side surface 51f than the conductive portion 68 for the third terminal.

[0249] The driver terminal conductive portion 155 is disposed on the rear surface 51b of the substrate 51 at a portion overlapping the driver circuit mounting portion 150 when viewed from the thickness direction Z. The shape and size of the driver terminal conductive portion 155 are the same as those of the driver circuit mounting portion 150. The first power supply terminal conductive portion 156 is disposed on the rear surface 51b of the substrate at a portion overlapping the first power supply conductive portion 151 when viewed from the thickness direction Z. The shape and size of the first power supply terminal conductive portion 156 are the same as those of the first power supply conductive portion 151. The second power supply terminal conductive portion 157 is disposed on the rear surface 51b of the substrate at a portion overlapping the second power supply conductive portion 152 when viewed from the thickness direction Z. The shape and size of the second power supply terminal conductive portion 157 are the same as those of the second power supply conductive portion 152. The signal terminal conductive portion 158 is disposed on the rear surface 51b of the substrate at a portion overlapping the signal conductive portion 153 when viewed from the thickness direction Z. The shape and size of the signal terminal conductive portion 158 are the same as those of the signal conductive portion 153. The reference voltage terminal conductive portion 159 is arranged in a portion of the back surface 51b of the substrate that overlaps with the reference voltage conductive portion 154 when viewed from the thickness direction Z. The shape and size of the reference voltage terminal conductive portion 159 are the same as those of the reference voltage conductive portion 154.

[0250] According to this configuration, the semiconductor laser element 10 is located at the center of the base material 51 in the lateral direction X. This eliminates any deviation of the semiconductor laser element 10 in the lateral direction X relative to the support substrate 50, and therefore the wiring pattern of the wiring board can be designed without taking into consideration the deviation of the semiconductor laser element 10. This improves the ease of use of the semiconductor laser device 1D.

[0251] Figure 40 shows the configuration of a semiconductor laser device 1D that is based on the semiconductor laser device 1A of the first embodiment, but in which the switching element 20 of the semiconductor laser device 1A is replaced with a horizontally structured switching element 20A of the semiconductor laser device 1C of the third embodiment, and in which a driver circuit 140 is built in.

[0252] 40, the first source electrode 22A, the second source electrode 22B, and the gate electrode 23 of the switching element 20A are each formed at an end of the element main surface 24a that is closer to the driver circuit 140. When viewed from the vertical direction Y, the first source electrode 22A overlaps with the first power supply electrode 144a and the second power supply electrode 144b of the driver circuit 140. When viewed from the vertical direction Y, the second source electrode 22B overlaps with the input electrode 144d, the signal electrode 144e, and the reference voltage output electrode 144f of the driver circuit 140. When viewed from the vertical direction Y, the gate electrode 23 overlaps with the output electrode 144c of the driver circuit 140.

[0253] The connection manner of each of the driver connecting members 161-165 is the same as the connection manner of each of the driver connecting members 161-165 in the fourth embodiment. The sixth driver connecting member 166 connects the input electrode 144d of the driver circuit 140 and the second source electrode 22B of the switching element 20A. The configuration of the back surface side conductive portion 60B is the same as the configuration of the back surface side conductive portion 60B in the fourth embodiment. The semiconductor laser device 1D shown in FIG. 40 can obtain the same effects as those in the fourth embodiment.

[0254] In the semiconductor laser device 1D shown in FIG. 40, the number of semiconductor laser elements 10 can be changed arbitrarily. As an example, as shown in FIG. 41, the semiconductor laser device 1D of FIG. 40 can be modified to include two semiconductor laser elements 10A and 10B. In this case, the shapes of the third drive conductive portion 63 and the fourth drive conductive portions 64A and 64B, the arrangement of the semiconductor laser elements 10A and 10B, and the connection of the laser connecting members 85 and 86 are the same as those of the semiconductor laser device 1A of the modified example shown in FIG. 17. Although not shown, the shapes and arrangement of the third terminal conductive portion 68 and the fourth terminal conductive portions 69A and 69B of the back-side conductive portion 60B are the same as those of the semiconductor laser device 1A of the modified example shown in FIG. 18.

[0255] In the semiconductor laser device 1D shown in FIG. 41, the anode electrodes 11 of the two semiconductor laser elements 10A and 10B may be connected to each other by an element connecting member 87, as shown in FIG.

[0256] In the semiconductor laser device 1D shown in FIGS. 41 and 42, the semiconductor laser elements 10A and 10B may be replaced with the semiconductor laser element 10C shown in FIGS. 20 and 21, as shown in FIG.

[0257] In the semiconductor laser device 1D of the fourth embodiment and its modified example, the driver circuit 140 is mounted on the base material main surface 51a of the base material 51 of the support substrate 50, but this is not limiting. For example, the driver circuit 140 may be embedded inside the support substrate 50. With this configuration, the switching element 20 and the driver circuit 140 are arranged side by side in the thickness direction Z, thereby making it possible to reduce the size of the semiconductor laser device 1D in the horizontal direction X or the vertical direction Y.

[0258] In the semiconductor laser device 1D of the fourth embodiment and its modified example, the wire diameter of each of the driver connecting members 161-166 may be different from the wire diameter of the other connecting members 80. In addition, the material constituting each of the driver connecting members 161-166 may be different from the material constituting the other connecting members 80.

[0259] [Fifth embodiment] A semiconductor laser device 1E of the fifth embodiment will be described with reference to Figures 44 to 46. The semiconductor laser device 1E of the present embodiment differs from the semiconductor laser device 1B of the second embodiment mainly in the shape of a part of the conductive portion 60. In this embodiment, for convenience, the same components as those in the second embodiment are denoted by the same reference numerals, and their description may be omitted.

[0260] 44, the semiconductor laser device 1E has, as main surface side conductive portions 60A, a first drive conductive portion 61, a third drive conductive portion 63, a fourth drive conductive portion 64, and a control conductive portion 65. In other words, the semiconductor laser device 1E does not have a second drive conductive portion 62.

[0261] The size in the vertical direction Y of the base material 51 of the support substrate 50 is larger than the size in the vertical direction Y of the base material 51 of the second embodiment. The size in the horizontal direction X of the base material 51 is equal to the size in the horizontal direction X of the base material 51 of the second embodiment. Therefore, the aspect ratio of the base material 51 in a plan view is different from the aspect ratio of the base material 51 of the second embodiment.

[0262] The arrangement of the first drive conductive portion 61, the third drive conductive portion 63, and the fourth drive conductive portion 64 is the same as in the second embodiment. The size in the vertical direction Y of the first drive conductive portion 61 is larger than the size in the vertical direction Y of the first drive conductive portion 61 in the second embodiment. The size in the vertical direction Y of the third drive conductive portion 63 is larger than the size in the vertical direction Y of the third drive conductive portion 63 in the second embodiment. More specifically, the size in the vertical direction Y of the switching element mounting portion 63a is larger than the size in the vertical direction Y of the switching element mounting portion 63a in the second embodiment. In this embodiment, both ends of the first drive conductive portion 61 in the vertical direction Y are defined as a first end portion 61a and a second end portion 61b. The first end portion 61a is the end portion of the first drive conductive portion 61 closer to the first substrate side surface 51c and is the end portion to which the first terminals 31 of the capacitors 30A and 30B are connected. The second end 61b is the end of the first driving conductive portion 61 that is closer to the second substrate side surface 51d.

[0263] The control conductive portion 65 is disposed closer to the second substrate side surface 51d than the third drive conductive portion 63. The control conductive portion 65 has a rectangular shape in plan view with its longer sides aligned in the horizontal direction X and its shorter sides aligned in the vertical direction Y. The size of the control conductive portion 65 in the horizontal direction X is larger than the size of the control conductive portion 65 of the second embodiment in the horizontal direction X.

[0264] As shown in FIG. 45, the semiconductor laser device 1E has first terminal conductive portions 66A and 66B, third terminal conductive portions 68A and 68B, a fourth terminal conductive portion 69, and a control terminal conductive portion 70 as the back-surface-side conductive portion 60B. That is, the semiconductor laser device 1E does not have a second terminal conductive portion 67. In this embodiment, the arrangement of the first terminal conductive portions 66A and 66B, the third terminal conductive portions 68A and 68B, and the fourth terminal conductive portion 69 is the same as in the second embodiment. The size in the horizontal direction X of each of the third terminal conductive portions 68A and 68B is smaller than the size in the horizontal direction X of each of the third terminal conductive portions 68A and 68B in the second embodiment. The size in the vertical direction Y of the third terminal conductive portion 68A is larger than the size in the vertical direction Y of the third terminal conductive portion 68A in the second embodiment.

[0265] The control terminal conductive portion 70 is disposed at a position overlapping the control conductive portion 65 in the thickness direction Z. The size of the control terminal conductive portion 70 in the horizontal direction X is larger than the size of the control terminal conductive portion 70 in the horizontal direction X of the second embodiment.

[0266] The semiconductor laser device 1E of this embodiment has, as the connection section 60C, first drive connection sections 73A and 73B, third drive connection sections 75A and 75B, a fourth drive connection section 76, and a control connection section 77. That is, the semiconductor laser device 1E does not have the second drive connection section 74. In this embodiment, the arrangement of the first drive connection sections 73A and 73B, the third drive connection sections 75A and 75B, and the fourth drive connection section 76 is the same as in the second embodiment. Unlike the second embodiment, this embodiment has four third drive connection sections 75A and two control connection sections 77. The four third drive connection sections 75A are arranged spaced apart from each other in the horizontal direction X and the vertical direction Y. The two control connection sections 77 are arranged at an interval in the horizontal direction X while aligned in the vertical direction Y.

[0267] As shown in FIG. 44, the size in the vertical direction Y of the switching element 20 mounted on the switching element mounting portion 63a of the third driving conductive portion 63 is larger than the size in the vertical direction Y of the switching element 20 of the second embodiment.

[0268] In this embodiment, the connection positions of the source electrode 22 and the first drive conductive portion 61 of the first drive connecting member 81 are different from those of the second embodiment. Specifically, for convenience, the three first drive connecting members 81 are referred to as first drive connecting members 81A, 81B, and 81C. The first drive connecting member 81A is the connecting member closest to the capacitors 30A and 30B among the three first drive connecting members 81A to 81C. The first drive connecting member 81C is the connecting member farthest from the capacitors 30A and 30B among the three first drive connecting members 81A to 81C. The first drive connecting member 81B is disposed between the first drive connecting member 81A and the first drive connecting member 81B in the vertical direction Y.

[0269] The first end 81ax of the first drive connecting member 81A, which is connected to the source electrode 22, is located closer to the first substrate side surface 51c than the center of the source electrode 22 in the longitudinal direction Y. The second end 81bx of the first drive connecting member 81A, which is connected to the first drive conductive section 61, is located closer to the first substrate side surface 51c than the center of the first drive conductive section 61 in the longitudinal direction Y. More specifically, the second end 81bx is located closer to the first substrate side surface 51c than the four first drive link sections 73 formed on the first drive conductive section 61. The second end 81bx is located closer to the second substrate side surface 51d than the first end 81ax in the longitudinal direction Y. Therefore, in a plan view, the first drive connecting member 81A extends from the first end 81ax toward the second substrate side surface 51d.

[0270] The first end 81ay of the first drive connection member 81B, which is connected to the source electrode 22, is located at a portion of the source electrode 22 that is closer to the first substrate side surface 51c than the center of the source electrode 22 in the longitudinal direction Y and closer to the center than the first end 81ax. The second end 81by of the first drive connection member 81B, which is connected to the first drive conductive portion 61, is located at a portion of the first drive conductive portion 61 that is closer to the first substrate side surface 51c than the center of the first drive conductive portion 61 in the longitudinal direction Y and closer to the center than the first end 81ax. More specifically, the second end 81by is located between the four first drive linking portions 73 in the longitudinal direction Y. The second end 81by is located closer to the second substrate side surface 51d in the longitudinal direction Y than the first end 81ay. Therefore, in a plan view, the first drive connection member 81B extends from the first end 81ay toward the second substrate side surface 51d.

[0271] A first end 81az of the first drive connecting member 81C connected to the source electrode 22 is located at a portion of the source electrode 22 that is closer to the second substrate side surface 51d than to the center of the source electrode 22 in the vertical direction Y. Specifically, the first end 81az is connected to a portion of the source electrode 22 that is adjacent to the notch 25 in the horizontal direction X. A second end 81bz of the first drive connecting member 81C connected to the first drive conductive portion 61 is located at a portion of the first drive conductive portion 61 that is closer to the second substrate side surface 51d than to the center of the first drive conductive portion 61 in the vertical direction Y. More specifically, a distance DY1 in the vertical direction Y between an edge 61c of the first drive conductive portion 61 that is closer to the second substrate side surface 51d and the second end 81bz is smaller than a distance DY2 in the vertical direction Y between the first terminal 31 of the capacitor 30B and the second end 81bz. The second end 81bz is connected to a portion of the first driving conductive portion 61 closer to the switching element 20 in the lateral direction X.

[0272] The second end 81bz is located closer to the second substrate side surface 51d in the longitudinal direction Y than the first end 81az. Therefore, in a plan view, the first drive connection member 81C extends toward the second substrate side surface 51d from the first end 81az to the second end 81bz. The distance DYC between the first end 81az and the second end 81bz in the longitudinal direction Y is greater than the distance DYA between the first end 81ax and the second end 81bx of the first drive connection member 81A in the longitudinal direction Y. The distance DYC is also greater than the distance DYB between the first end 81ay and the second end 81by of the first drive connection member 81B in the longitudinal direction Y.

[0273] As can be seen from FIG. 44, the second end 81bx of the first drive connection member 81A is located closer to the capacitors 30A and 30B than the second end 81by and 81bz of the first drive connection members 81B and 81C. Therefore, the first drive connection member 81A can be said to be the drive connection member that is closer to the capacitors 30A and 30B among the multiple drive connection members. In other words, the first drive connection member 81A can be said to be the first drive connection member that connects the side of the drive conductive portion (first drive conductive portion 61) that is closer to the first terminals 31 of the capacitors 30A and 30B to the second drive electrode (source electrode 22 of the switching element 20). Furthermore, the second end 81bz of the first drive connection member 81C is located farther from the capacitors 30A and 30B than the second end 81bx and 81by of the first drive connection members 81A and 81C. The second end 81bz is disposed closer to the edge 61c of the first drive conductive portion 61 than the first terminals 31 of the capacitors 30A and 30B. For this reason, the first drive connection member 81C can be considered to be the drive connection member farther from the capacitors 30A and 30B among the multiple drive connection members. In other words, the first drive connection member 81C can be considered to be a second drive connection member that connects the side of the drive conductive portion (first drive conductive portion 61) that is closer to the second end (edge ​​61c) than the first terminals 31 of the capacitors 30A and 30B to the second drive electrode (source electrode 22 of the switching element 20).

[0274] FIG. 46 is a schematic diagram illustrating a case where the semiconductor laser device 1E of this embodiment is applied to a laser system 100. As shown in FIG. 46, a positive electrode 111 of a power supply 110 is connected to the fourth drive conductive portion 64 via a fourth terminal conductive portion 69 and a fourth drive connecting portion 76 (both see FIG. 45). A negative electrode 112 of the power supply 110 is connected to the first drive conductive portion 61 via a first terminal conductive portion 66A and a first drive connecting portion 73A (both see FIG. 45). In FIG. 45, the negative electrode 112 is connected to a portion of the first terminal conductive portion 66A that is closer to the capacitors 30A and 30B than the center portion in the vertical direction Y. An output electrode 141 of a driver circuit 140 is connected to the control conductive portion 65 via a control terminal conductive portion 70 and a control connecting portion 77 (both see FIG. 45). The input electrode 142 of the driver circuit 140 is connected to the first drive conductive portion 61 via the first terminal conductive portion 66B and the first drive connecting portion 73B (both see FIG. 45). In this manner, the input electrode 142 is electrically connected to the end of the first drive conductive portion 61 closer to the second substrate side surface 51d. The output electrode 141 of the driver circuit 140 is electrically connected to the gate electrode 23 via the control conductive portion 65 and the control connecting member 84. The input electrode 142 of the driver circuit 140 is electrically connected to the source electrode 22 via the first drive conductive portion 61 and the first drive connecting member 81C.

[0275] When the laser system 100 is driven, a drive current loop is formed in which a current flows in the following order: the positive electrode 111 of the power supply 110, the anode electrode 11 and cathode electrode 12 of the semiconductor laser element 10, the drain electrode 21 and source electrode 22 of the switching element 20, the first drive connecting member 81A, and the negative electrode 112 of the power supply 110. Also, a control current loop is formed in which a current flows in the following order: the output electrode 141 of the driver circuit 140, the control conductive part 65, the control connecting member 84, the source electrode 22, the first drive connecting member 81C, the first drive conductive part 61, and the input electrode 142. These current loops are formed independently of each other.

[0276] According to the semiconductor laser device 1E of this embodiment, the following effects can be obtained. (5-1) The semiconductor laser device 1E includes a first drive connecting member 81A connected to the source electrode 22 of the switching element 20 and a side of the first drive conductive portion 61 closer to the first terminals 31 of the capacitors 30A and 30B, and a first drive connecting member 81C connecting the source electrode 22 to a side of the first drive conductive portion 61 closer to the gate electrode 23 than the first terminals 31 of the capacitors 30A and 30B. With this configuration, a drive loop is formed as a first path for current flowing from the source electrode 22 of the switching element 20 via the first drive connecting member 81A to the side of the first drive conductive portion 61 closer to the first terminals 31 of the capacitors 30A and 30B, and a control loop is formed as a second path for current flowing from the source electrode 22 via the first drive connecting member 81C to the side of the first drive conductive portion 61 closer to the gate electrode 23. This reduces the influence of fluctuations in the current in the drive loop on the control loop. That is, the control loop is less susceptible to the influence of the inductance of the first drive connecting member 81. Therefore, in the control loop, it is possible to reduce the influence of the back electromotive force caused by the inductance of the first drive connecting member 81A on the voltage Vgs applied to the gate electrode 23 of the switching element 20.

[0277] (5-2) The semiconductor laser element 10 can emit laser light with a pulse width of 10 ns or less. With this configuration, as the pulse width becomes shorter, the shortest possible current path is formed among the current paths through which current can flow in the drive loop, and therefore, current flows from the source electrode 22 of the switching element 20 through the first drive connecting member 81A, which is closest to the capacitors 30A and 30B. This reduces the influence of the drive loop on the first drive connecting member 81C, which is farthest from the capacitors 30A and 30B.

[0278] [Modification of the fifth embodiment] In the fifth embodiment, the configuration of the semiconductor laser device 1B of the second embodiment is assumed, but the shape of the conductive portion 60 is different from that of the conductive portion 60 of the second embodiment. However, this is not limited to this. For example, the configurations of the semiconductor laser devices 1A and 1C of the first and third embodiments may be assumed. When the configuration of the semiconductor laser device 1A of the first embodiment is assumed, and when the configuration of the semiconductor laser device 1C of the third embodiment is assumed, for example, the first drive conductive portion 61B and the second drive conductive portion 62 are integrated. With this configuration, the same effects as those of the fifth embodiment can be obtained.

[0279] [Modifications common to all embodiments] The above-described embodiments are merely examples of possible forms of the semiconductor laser device according to the present disclosure, and are not intended to limit the forms. The semiconductor laser device according to the present disclosure may take forms different from those exemplified in the above-described embodiments. Examples of such forms include forms in which part of the configuration of the above-described embodiments is replaced, modified, or omitted, or forms in which new configurations are added to the above-described embodiments. In the following modified examples, parts common to the above-described embodiments are assigned the same reference numerals as the above-described embodiments, and descriptions thereof will be omitted.

[0280] In the above embodiments, the capacitors 30A and 30B are mounted on the base material main surface 51a of the base material 51 of the support substrate 50, but the positions of the capacitors 30A and 30B are not limited to this. For example, the capacitors 30A and 30B may be embedded inside the support substrate 50.

[0281] In the above embodiments, the connecting portion 60C has a configuration in which the conductor portion 72 is embedded in the through-hole 71, but the configuration of the connecting portion 60C is not limited to this. At least one of the multiple connecting portions 60C may have a configuration in which an insulating material is embedded in the through-hole 71 instead of the conductor portion 72.

[0282] In the above embodiments, the wire diameters of the first drive connecting members 81, 82, the second drive connecting member 83, the control connecting member 84, and the laser connecting members 85, 86 are all equal, but this is not limiting. The wire diameters of the first drive connecting members 81, 82, the second drive connecting member 83, the control connecting member 84, and the laser connecting members 85, 86 may be set individually. For example, the wire diameter of the control connecting member 84 may be smaller than the wire diameters of the drive connecting members 81-83 and the laser connecting members 85, 86.

[0283] In the above embodiments, the first drive connecting members 81, 82, the second drive connecting member 83, the control connecting member 84, and the laser connecting members 85, 86 are made of the same material, but this is not limiting. For example, the material of the control connecting member 84 may be different from the materials of the drive connecting members 81 to 83 and the laser connecting members 85, 86.

[0284] In the above embodiments, the diode 130 of the laser system 100 is provided outside the semiconductor devices 1A to 1E, but this is not limiting. The semiconductor devices 1A to 1E may be configured to have the diode 130 built in.

[0285] The technical ideas that can be understood from the above-described embodiment and the above-described modified examples will be described below. (Appendix 1) a semiconductor laser element; a switching element connected in series to the semiconductor laser element, having a control electrode, a first drive electrode, and a second drive electrode, and controlling a current flowing through the semiconductor laser element in response to a voltage applied to the control electrode; a capacitor connected in parallel to the semiconductor laser element and the switching element; a first driving conductive portion to which a first terminal of the capacitor is connected; a second driving conductive portion disposed apart from the first driving conductive portion; a first drive connecting member connecting the first drive conductive portion and the second drive electrode; a second drive connecting member connecting the second drive conductive portion and the second drive electrode; Semiconductor laser device.

[0286] (Appendix 2) the semiconductor laser device includes a terminal conductive portion that forms a terminal of the semiconductor laser device, The terminal conductive portion is a first terminal conductive portion for connecting to a negative electrode of a power source that supplies power to the semiconductor laser device; a second terminal conductive portion for connection to an input electrode of a driver circuit that applies a voltage to the control electrode of the switching element, the first driving conductive portion is electrically connected to the first terminal conductive portion, The second driving conductive portion is electrically connected to the second terminal conductive portion. 2. The semiconductor laser device according to claim 1.

[0287] (Appendix 3) the semiconductor laser element, the switching element, and the second driving conductive portion are arranged in a predetermined first direction in a plan view of the semiconductor laser device, The first driving conductive portions are arranged in a second direction perpendicular to the first direction with respect to the switching elements in the plan view. 3. The semiconductor laser device according to claim 1 or 2.

[0288] (Appendix 4) In the first direction, the second driving conductive portion is disposed on the opposite side of the switching element from the semiconductor laser element. 4. The semiconductor laser device according to claim 3.

[0289] (Appendix 5) The semiconductor laser element is disposed at the center in the second direction. 5. The semiconductor laser device according to claim 3 or 4.

[0290] (Appendix 6) The capacitor is disposed closer to the semiconductor laser element than the switching element in the first direction. 6. The semiconductor laser device according to any one of claims 3 to 5.

[0291] (Appendix 7) A plurality of the capacitors are provided. 7. The semiconductor laser device according to any one of claims 1 to 6.

[0292] (Appendix 8) a plurality of the capacitors are provided, and are arranged on both sides of the switching element in the second direction; The first driving conductive portions are disposed on both sides of the switching element in the second direction. 7. The semiconductor laser device according to any one of claims 3 to 6.

[0293] (Appendix 9) The semiconductor laser elements are provided in plurality and are arranged in the second direction. 7. The semiconductor laser device according to any one of claims 3 to 6.

[0294] (Appendix 10) The electrodes of the semiconductor laser elements adjacent to each other in the second direction are electrically connected to each other by an element connecting member. 10. The semiconductor laser device according to claim 9.

[0295] (Appendix 11) the semiconductor laser element has a plurality of semiconductor light-emitting layers arranged in the second direction, The plurality of semiconductor light emitting layers are connected to each other by one electrode. The semiconductor laser device according to any one of Supplementary Note 3 to 6 or Supplementary Note 8 or 9.

[0296] (Appendix 12) a third driving conductive portion to which the first driving electrode of the switching element is connected, The semiconductor laser element is connected to the third driving conductive portion. 12. The semiconductor laser device according to claim 1.

[0297] (Appendix 13) a fourth driving conductive portion to which the second terminal of the capacitor is connected, In a plan view of the semiconductor laser device, the semiconductor laser element, the switching element, and the second driving conductive portion are arranged in a predetermined first direction, The fourth driving conductive portions are arranged in the first direction relative to the first driving conductive portions. 13. The semiconductor laser device according to any one of claims 1 to 12.

[0298] (Appendix 14) The semiconductor laser device comprises: a control conductive portion that is disposed apart from the first drive conductive portion and the second drive conductive portion and is electrically connected to the control electrode; a control connection member that connects the control electrode and the control conductive portion, The control connection member and the second drive connection member are adjacent to each other. 14. The semiconductor laser device according to any one of claims 1 to 13.

[0299] (Appendix 15) The control conductive portion and the second drive conductive portion are adjacent to each other. 15. The semiconductor laser device according to claim 14.

[0300] (Appendix 16) the semiconductor laser device includes a support substrate having a substrate main surface and a substrate back surface facing the opposite side to the substrate main surface in a direction perpendicular to the substrate main surface; At least the first driving conductive portion is formed on the main surface of the substrate, A terminal conductive portion that constitutes a terminal of the semiconductor laser device is formed on the rear surface of the substrate. 16. The semiconductor laser device according to any one of claims 1 to 15.

[0301] (Appendix 17) The terminal conductive portion is a first terminal conductive portion for connecting to a negative electrode of a power source that supplies power to the semiconductor laser device; a second terminal conductive portion for connection to an input electrode of a driver circuit that applies a voltage to the control electrode of the switching element; a third terminal conductive portion for connection to the first drive electrode of the switching element, The first terminal conductive portion is disposed apart from the third terminal conductive portion. 17. The semiconductor laser device according to claim 16.

[0302] (Appendix 18) the semiconductor laser device includes a third driving conductive portion to which the first driving electrode of the switching element is connected, the terminal conductive portion includes a third terminal conductive portion electrically connected to the third driving conductive portion, The first terminal conductive portion and the third terminal conductive portion are integrated together. 18. The semiconductor laser device according to claim 17.

[0303] (Appendix 19) a connecting portion that electrically connects the first driving conductive portion and the second driving conductive portion to the terminal conductive portion; 19. The semiconductor laser device according to any one of claims 16 to 18.

[0304] (Appendix 20) The semiconductor laser device includes a sealing member that seals the semiconductor laser element, the switching element, the capacitor, the first driving conductive portion, the second driving conductive portion, the first driving connecting member, and the second driving connecting member and has a portion that transmits laser light from the semiconductor laser element. 20. The semiconductor laser device according to any one of claims 1 to 19.

[0305] (Appendix 21) a semiconductor laser element; a switching element connected in series to the semiconductor laser element, having a control electrode, a first drive electrode, and a second drive electrode, and controlling a current flowing through the semiconductor laser element in response to a voltage applied to the control electrode; a capacitor connected in parallel to the semiconductor laser element and the switching element; a first driving conductive portion to which the first terminal of the capacitor is connected, the first driving conductive portion has a first end portion to which a first terminal of the capacitor is connected, and a second end portion provided on the opposite side to the first end portion in an extension direction of the first driving conductive portion, a first drive connecting member connecting the second drive electrode to a side of the first drive conductive portion that is closer to the first terminal of the capacitor; a second drive connecting member connecting the second drive electrode to a side of the first drive conductive portion closer to the second end than the first terminal of the capacitor; Equipped with Semiconductor laser device.

[0306] (Appendix 22) the semiconductor laser element has a main surface and a rear surface facing opposite directions; the second drive electrode and the control electrode are each formed on the element principal surface, The control electrode is disposed on the side farther from the first driving conductive portion than the second driving electrode. 22. The semiconductor laser device according to claim 21.

[0307] (Appendix 23) The position where the second drive connection member is connected to the second drive electrode is closer to the control electrode than the position where the first drive connection member is connected to the second drive electrode. 23. The semiconductor laser device according to claim 21 or 22.

[0308] (Appendix 24) The semiconductor laser device includes a sealing member that seals the semiconductor laser element, the switching element, the capacitor, the first driving conductive portion, the first driving connecting member, and the second driving connecting member and has a portion that transmits laser light from the semiconductor laser element. 24. The semiconductor laser device according to any one of claims 21 to 23.

[0309] (Appendix 25) a semiconductor laser element; a switching element connected in series to the semiconductor laser element, having a control electrode, a first drive electrode, and a second drive electrode, and controlling a current flowing through the semiconductor laser element in response to a voltage applied to the control electrode; a capacitor connected in parallel to the semiconductor laser element and the switching element; a first driving conductive portion to which a first terminal of the capacitor is connected; a driver circuit that applies a voltage to the control electrode of the switching element; a first drive connecting member connecting the first drive conductive portion and the second drive electrode; a second drive connection member connecting the driver circuit and the second drive electrode; Semiconductor laser device.

[0310] (Appendix 26) the semiconductor laser elements and the switching elements are arranged in a predetermined first direction in a plan view of the semiconductor laser device, the first driving conductive portions are arranged in a second direction perpendicular to the first direction in the plan view with respect to the switching elements, The driver circuit is disposed on the opposite side of the switching element to the side on which the semiconductor laser element is disposed in the first direction. 26. The semiconductor laser device according to claim 25.

[0311] (Appendix 27) the semiconductor laser elements and the switching elements are arranged in a predetermined first direction in a plan view of the semiconductor laser device, the first driving conductive portions are arranged in a second direction perpendicular to the first direction in the plan view with respect to the switching elements, The driver circuit is disposed on the opposite side of the switching element in the second direction from the side on which the first driving conductive portion is disposed. 26. The semiconductor laser device according to claim 25.

[0312] (Appendix 28) The second drive connection member is connected to the driver circuit side of the second drive electrode. 28. The semiconductor laser device according to any one of claims 25 to 27.

[0313] (Appendix 29) the driver circuit is formed as a chip having a main surface and a back surface facing opposite directions; an input electrode to which the second drive connection member is connected and an output electrode electrically connected to the control electrode are formed on the main surface; the control electrode and the output electrode are connected by a control connection member, When viewed in a direction perpendicular to the main surface, the input electrode and the output electrode are adjacent to each other. 29. The semiconductor laser device according to any one of claims 25 to 28.

[0314] (Appendix 30) The semiconductor laser device includes a sealing member that seals the semiconductor laser element, the switching element, the capacitor, the first driving conductive portion, the driver circuit, the first driving connecting member, and the second driving connecting member and has a portion that transmits laser light from the semiconductor laser element. 30. The semiconductor laser device according to any one of claims 25 to 29.

[0315] (Appendix 31) The first drive connecting member and the second drive connecting member are each made of a wire. 31. The semiconductor laser device according to any one of claims 1 to 30.

[0316] (Appendix 32) the first drive connecting member is made up of a plurality of wires, The second drive connecting member is made of a single wire. 32. The semiconductor laser device according to claim 31.

[0317] (Appendix 33) The wire diameter of the first drive connecting member and the wire diameter of the second drive connecting member are equal to each other. 33. The semiconductor laser device according to claim 31 or 32.

[0318] (Appendix 34) the switching element has a main surface and a back surface facing opposite directions; the second drive electrode and the control electrode are each formed on the element principal surface, The first drive electrode is formed on the rear surface of the element. Attachment 1 - 33 -- the semiconductor laser device of any one of claims 1 to 33.

[0319] (Appendix 35) the switching element has a main surface and a back surface facing opposite directions; The first drive electrode, the second drive electrode, and the control electrode are each formed on the main surface of the element. Attachment 1 - 33 -- the semiconductor laser device of any one of claims 1 to 33.

[0320] (Appendix 36) the semiconductor laser elements and the switching elements are arranged in a predetermined first direction in a plan view of the semiconductor laser device, the first drive electrode is disposed on the semiconductor laser element side of the element principal surface in the first direction, The second drive electrode and the control electrode are disposed on the device principal surface on the opposite side to the semiconductor laser device side in the first direction. 36. The semiconductor laser device according to claim 35.

[0321] (Appendix 37) The semiconductor laser device comprises: a support substrate having a substrate main surface on which the first driving conductive portion is formed, a substrate back surface facing the opposite side to the substrate main surface in a thickness direction, and a substrate side surface provided between the substrate main surface and the substrate back surface in the thickness direction and extending in a direction intersecting the substrate main surface and the substrate back surface; a terminal conductive portion formed on the rear surface of the substrate and constituting a terminal of the semiconductor laser device; a connecting portion connecting the first driving conductive portion and the terminal conductive portion, a recess recessed inward from the substrate side surface, The connecting portion is provided in the recess. 37. The semiconductor laser device according to any one of claims 1 to 36.

[0322] (Appendix 38) The semiconductor laser element is capable of emitting laser light with a pulse width of 10 ns or less. 38. The semiconductor laser device according to any one of claims 1 to 37.

[0323] (Appendix 39) a semiconductor laser element; a switching element connected in series to the semiconductor laser element, having a control electrode, a first drive electrode, and a second drive electrode, and controlling a current flowing through the semiconductor laser element in response to a voltage applied to the control electrode; a capacitor connected in parallel to the semiconductor laser element and the switching element; a first driving conductive portion to which a first terminal of the capacitor is connected; a second driving conductive portion disposed apart from the first driving conductive portion; Equipped with A semiconductor laser device in which a first path for current flowing from the second drive electrode to the first drive conductive portion and a second path for current flowing from the second drive electrode to the second drive conductive portion are formed separately. [Explanation of symbols]

[0324] 1A, 1B, 1C, 1D, 1E...Semiconductor laser device 10, 10A, 10B, 10C...Semiconductor laser element 14, 14A, 14B...Semiconductor light-emitting layer 17...Contact electrode (1 electrode) 20, 20A...Switching element 21...Drain electrode (first drive electrode) 22, 22A, 22B...Source electrodes (second drive electrodes) 23...Gate electrode (control electrode) 24a...Element main surface 24b...back side of element 30, 30A, 30B... Capacitors 31…1st terminal 32…Second terminal 42...Second power supply terminal (power supply terminal for connecting to the negative pole of the power supply) 45...Driver connection terminal (connection terminal) 50...Support substrate 51...Base material 51a...Main surface of substrate (main surface of substrate) 51b...Back surface of substrate (back surface of board) 51c…First base material side (board side) 51d…Second base material side (board side) 51e…Third base material side (board side) 51f…4th base material side (board side) 53A, 53B...recess 54A, 54B, 54C...recesses 55A, 55B, 55C...recesses 60...Conductive part 60B…Back side conductive part (conductive part for terminal) 60C... Liaison Department 60D...Side contact part (contact part) 61, 61A, 61B...First driving conductive portion 61a...first end 61b…Second end 62...Second driving conductive part 63...Third driving conductive part 64, 64A, 64B...Fourth driving conductive part 65...Control conductive part 66,66A,66B...Conductive part for first terminal 67...Conductive part for second terminal 68,68A,68B...Conductive part for third terminal 81, 81A, 81B, 82...First drive connecting members 81C...First drive connecting member (second drive connecting member) 83...Second driving connection member 84...Control connection member 87...Element connecting member 90...Sealing member 110…Power supply 111...Positive electrode 112...Negative electrode 140...Driver circuit 141...Output electrode 142...input electrode 143...Sealing member 143a... Sealing main surface (main surface of driver circuit) 144c...Output electrode 144d...Input electrode X…Horizontal direction (second direction) Y: Vertical direction (first direction)

Claims

1. a substrate having a first surface; a first semiconductor laser element mounted on the first surface; a switching element mounted on the first surface and controlling a current flowing through the first semiconductor laser element; a first capacitor mounted on the first surface; Equipped with the first semiconductor laser element is connected in series to the switching element, the first capacitor is connected in parallel to the first semiconductor laser element and the switching element, the first semiconductor laser element overlaps the switching element when viewed from a first direction parallel to the first surface, the first capacitor overlaps with at least one of the first semiconductor laser element and the switching element when viewed from a second direction that is parallel to the first surface and perpendicular to the first direction, the substrate includes a first conductive portion, and the first semiconductor laser element and the switching element are mounted on the first conductive portion; Semiconductor laser device.

2. the substrate includes a second conductive portion and a third conductive portion spaced apart from the first conductive portion, and the first capacitor is mounted on the second conductive portion and the third conductive portion; 2. The semiconductor laser device according to claim 1.

3. A substrate having a first surface; a first semiconductor laser element mounted on the first surface; a switching element mounted on the first surface and controlling a current flowing through the first semiconductor laser element; a first capacitor mounted on the first surface; A semiconductor laser device comprising: the first semiconductor laser element is connected in series to the switching element, the first capacitor is connected in parallel to the first semiconductor laser element and the switching element, the first semiconductor laser element overlaps the switching element when viewed from a first direction parallel to the first surface, the first capacitor overlaps with at least one of the first semiconductor laser element and the switching element when viewed from a second direction that is parallel to the first surface and perpendicular to the first direction, the semiconductor laser device further includes a second capacitor, and the switching element is located between the first capacitor and the second capacitor when viewed from the first direction. Semiconductor laser device.

4. A substrate having a first surface; a first semiconductor laser element mounted on the first surface; a switching element mounted on the first surface and controlling a current flowing through the first semiconductor laser element; a first capacitor mounted on the first surface; A semiconductor laser device comprising: the first semiconductor laser element is connected in series to the switching element, the first capacitor is connected in parallel to the first semiconductor laser element and the switching element, the first semiconductor laser element overlaps the switching element when viewed from a first direction parallel to the first surface, the first capacitor overlaps with at least one of the first semiconductor laser element and the switching element when viewed from a second direction that is parallel to the first surface and perpendicular to the first direction, the semiconductor laser device further includes a second capacitor, and the first semiconductor laser element is located between the first capacitor and the second capacitor when viewed from the first direction. Semiconductor laser device.

5. the switching element has a control electrode, a first drive electrode, and a second drive electrode, and controls a current flowing through the first semiconductor laser element in accordance with a voltage applied to the control electrode.

5. The semiconductor laser device according to claim 1.

6. the switching element has a main surface and a back surface facing opposite directions; the first drive electrode, the second drive electrode, and the control electrode are each formed on the element main surface; 6. The semiconductor laser device according to claim 5.

7. the switching element has a main surface and a back surface facing opposite directions; the second drive electrode and the control electrode are each formed on the element main surface, the first drive electrode is formed on a rear surface of the element; 6. The semiconductor laser device according to claim 5.

8. the first semiconductor laser element is disposed in the center in the second direction, 8. The semiconductor laser device according to claim 1.

9. an end of the switching element on the first semiconductor laser element side overlaps with the first capacitor when viewed from the second direction; 9. The semiconductor laser device according to claim 1.

10. an end portion of the first semiconductor laser element on the switching element side overlaps with the first capacitor when viewed from the second direction; 10. The semiconductor laser device according to claim 1.

11. a second semiconductor laser element is further provided, and the first semiconductor laser element and the second semiconductor laser element overlap each other when viewed from the second direction; 11. The semiconductor laser device according to claim 1.

12. the first semiconductor laser element has a plurality of semiconductor light emitting layers arranged in the second direction, the plurality of semiconductor light emitting layers are connected to each other by one electrode; 12. The semiconductor laser device according to claim 1.

13. A substrate having a first surface; a first semiconductor laser element mounted on the first surface; a switching element mounted on the first surface and controlling a current flowing through the first semiconductor laser element; a first capacitor mounted on the first surface; Equipped with the first semiconductor laser element is connected in series to the switching element, the first capacitor is connected in parallel to the first semiconductor laser element and the switching element, the first semiconductor laser element overlaps the switching element when viewed from a first direction parallel to the first surface, the first capacitor overlaps with at least one of the first semiconductor laser element and the switching element when viewed from a second direction that is parallel to the first surface and perpendicular to the first direction, the switching element has a control electrode, a first drive electrode, and a second drive electrode, and controls a current flowing through the first semiconductor laser element in response to a voltage applied to the control electrode; the switching element has a main surface and a back surface facing opposite directions; the first drive electrode, the second drive electrode, and the control electrode are each formed on the element main surface; Semiconductor laser device.

14. A substrate having a first surface; a first semiconductor laser element mounted on the first surface; a switching element mounted on the first surface and controlling a current flowing through the first semiconductor laser element; a first capacitor mounted on the first surface; Equipped with the first semiconductor laser element is connected in series to the switching element, the first capacitor is connected in parallel to the first semiconductor laser element and the switching element, the first semiconductor laser element overlaps the switching element when viewed from a first direction parallel to the first surface, the first capacitor overlaps with at least one of the first semiconductor laser element and the switching element when viewed from a second direction that is parallel to the first surface and perpendicular to the first direction, the switching element has a control electrode, a first drive electrode, and a second drive electrode, and controls a current flowing through the first semiconductor laser element in response to a voltage applied to the control electrode; the switching element has a main surface and a back surface facing opposite directions; the second drive electrode and the control electrode are each formed on the element main surface, the first drive electrode is formed on a rear surface of the element; Semiconductor laser device.

15. A substrate having a first surface; a first semiconductor laser element mounted on the first surface; a switching element mounted on the first surface and controlling a current flowing through the first semiconductor laser element; a first capacitor mounted on the first surface; Equipped with the first semiconductor laser element is connected in series to the switching element, the first capacitor is connected in parallel to the first semiconductor laser element and the switching element, the first semiconductor laser element overlaps the switching element when viewed from a first direction parallel to the first surface, the first capacitor overlaps with at least one of the first semiconductor laser element and the switching element when viewed from a second direction that is parallel to the first surface and perpendicular to the first direction, the first semiconductor laser element is disposed in the center in the second direction, Semiconductor laser device.

16. A substrate having a first surface; a first semiconductor laser element mounted on the first surface; a switching element mounted on the first surface and controlling a current flowing through the first semiconductor laser element; a first capacitor mounted on the first surface; Equipped with the first semiconductor laser element is connected in series to the switching element, the first capacitor is connected in parallel to the first semiconductor laser element and the switching element, the first semiconductor laser element overlaps the switching element when viewed from a first direction parallel to the first surface, the first capacitor overlaps with at least one of the first semiconductor laser element and the switching element when viewed from a second direction that is parallel to the first surface and perpendicular to the first direction, an end of the switching element on the first semiconductor laser element side overlaps with the first capacitor when viewed from the second direction; Semiconductor laser device.

17. A substrate having a first surface; a first semiconductor laser element mounted on the first surface; a switching element mounted on the first surface and controlling a current flowing through the first semiconductor laser element; a first capacitor mounted on the first surface; Equipped with the first semiconductor laser element is connected in series to the switching element, the first capacitor is connected in parallel to the first semiconductor laser element and the switching element, the first semiconductor laser element overlaps the switching element when viewed from a first direction parallel to the first surface, the first capacitor overlaps with at least one of the first semiconductor laser element and the switching element when viewed from a second direction that is parallel to the first surface and perpendicular to the first direction, an end portion of the first semiconductor laser element on the switching element side overlaps with the first capacitor when viewed from the second direction; Semiconductor laser device.

18. A substrate having a first surface; a first semiconductor laser element mounted on the first surface; a switching element mounted on the first surface and controlling a current flowing through the first semiconductor laser element; a first capacitor mounted on the first surface; A semiconductor laser device comprising: the first semiconductor laser element is connected in series to the switching element, the first capacitor is connected in parallel to the first semiconductor laser element and the switching element, the first semiconductor laser element overlaps the switching element when viewed from a first direction parallel to the first surface, the first capacitor overlaps with at least one of the first semiconductor laser element and the switching element when viewed from a second direction that is parallel to the first surface and perpendicular to the first direction, the semiconductor laser device further includes a second semiconductor laser element, and the first semiconductor laser element and the second semiconductor laser element overlap when viewed from the second direction. Semiconductor laser device.

19. A substrate having a first surface; a first semiconductor laser element mounted on the first surface; a switching element mounted on the first surface and controlling a current flowing through the first semiconductor laser element; a first capacitor mounted on the first surface; Equipped with the first semiconductor laser element is connected in series to the switching element, the first capacitor is connected in parallel to the first semiconductor laser element and the switching element, the first semiconductor laser element overlaps the switching element when viewed from a first direction parallel to the first surface, the first capacitor overlaps with at least one of the first semiconductor laser element and the switching element when viewed from a second direction that is parallel to the first surface and perpendicular to the first direction, the first semiconductor laser element has a plurality of semiconductor light emitting layers arranged in the second direction, the plurality of semiconductor light emitting layers are connected to each other by one electrode; Semiconductor laser device.

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