Optical Measuring Device

Abstract

To radiate heat of a light-emitting element efficiently.SOLUTION: A light-emitting device includes a base material, an electrode disposed on a surface of the base material, having a light-emitting element on a surface of the electrode, and electrically connected to the light-emitting element, a connection part disposed at a position apart from the electrode on the surface of the base material and connected to a conductive part with a reference potential, and a heat transfer member having a contact surface along the surface of the base material, the contact surface being in contact with the surface of the electrode and a surface of the connection part so as to transfer heat from the electrode to the connection part.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a light emitting device, a heat transfer member, and an optical measurement device. [Background technology]

[0002] Patent Document 1 discloses a chip-type heat-generating component for surface mounting, which is characterized by having electrodes for heat dissipation provided to dissipate heat generated in the main body, and which is composed of a main body functioning as a circuit element and electrodes providing both electrical and mechanical connections.

[0003] Patent Document 2 discloses a heat conduction means for dissipating heat from an electrical component, characterized in that, in an electrical wiring printed board on which electrical components are mounted, any heat conductor for transmitting heat generated by the electrical component is continuously arranged on any wiring on the board. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 6-169189 [Patent Document 2] Japanese Patent Application Publication No. 10-84175 Summary of the Invention [Problem to be solved by the invention]

[0005] A light-emitting device may be a light-emitting device that includes a substrate such as a printed circuit board, an electrode disposed on the surface of the substrate, and a light-emitting element disposed on the surface of the electrode, with the electrode electrically connected to the light-emitting element. In this light-emitting device, if heat generated by the light-emitting element is transferred only from the electrode to the substrate, the heat of the light-emitting element may not be dissipated efficiently.

[0006] An object of the present invention is to dissipate heat from a light-emitting element more efficiently than in a configuration in which heat generated in the light-emitting element is transferred only from the electrodes to the base material. [Means for solving the problem]

[0007] A first aspect comprises a substrate, an electrode arranged on a surface of the substrate, having a light-emitting element arranged on its surface and electrically connected to the light-emitting element, a connection portion arranged at a position spaced apart from the electrode on the surface of the substrate and connected to a conductive portion having a reference potential, and a heat transfer member having a contact surface along the surface of the substrate, the contact surface being in contact with a surface of the electrode and a surface of the connection portion, and transferring heat from the electrode to the connection portion.

[0008] In a second embodiment, the heat transfer member is an insulator.

[0009] In a third aspect, the heat transfer member is metallized at the contact surface such that a contact portion with the surface of the electrode and a contact portion with the surface of the connection portion are each electrically isolated from each other.

[0010] A fourth aspect includes a driving unit that is arranged on one side along the surface of the substrate relative to the light-emitting element and drives the light-emitting element, the electrode extends from the light-emitting element in a direction opposite to the driving unit relative to the light-emitting element, and the contact surface contacts the extended portion of the electrode.

[0011] In a fifth aspect, the connection portion is arranged on the opposite side of the extension portion, the heat transfer member is arranged from the extension portion toward the opposite side, and the contact surface contacts the connection portion on the opposite side of the extension portion.

[0012] In a sixth aspect, the extension portion has a width in an intersecting direction intersecting with the opposite direction that is wider than the portion in which the light emitting element is arranged.

[0013] In a seventh aspect, a direction in which the heat transfer member transfers heat from the electrode to the connection portion differs from a direction in which a current flows between the light emitting element and the electrode.

[0014] In an eighth aspect, the heat transfer member has a higher thermal conductivity than the base material.

[0015] A ninth aspect comprises a substrate, an electrode arranged on a surface of the substrate, having a light-emitting element arranged on its surface and electrically connected to the light-emitting element, a connection portion arranged at a position spaced apart from the electrode on the surface of the substrate and connected to a conductive portion having a reference potential, and a heat transfer member made of an insulator, in contact with a surface of the electrode and a surface of the connection portion, and transferring heat from the electrode to the connection portion.

[0016] The tenth embodiment comprises a first contact portion in contact with a heat transfer object that removes heat, and a second contact portion in contact with a heat transfer object that transfers heat, and is made of an insulator with high thermal conductivity, and each of the first contact portion and the second contact portion is metallized in an electrically isolated state.

[0017] An eleventh aspect includes a light emitting device according to any one of the first to ninth aspects, a light receiving unit that receives reflected light from an object irradiated with light from the light emitting device, and a processing unit that processes information related to the light received by the light receiving unit to measure the distance from the light emitting device to the object or the shape of the object. Effect of the Invention

[0018] According to the configuration of the first aspect, the heat generated in the light emitting element can be dissipated more efficiently than in a configuration in which the heat is transferred only from the electrodes to the base material.

[0019] According to the configuration of the second aspect, electrical conduction between the electrodes and the connection parts is suppressed, compared to a configuration in which the heat transfer member is a conductor.

[0020] According to the configuration of the third aspect, the electrodes and the connection parts can be bonded to the heat transfer member using a bonding material that has an affinity for metal.

[0021] According to the configuration of the fourth aspect, the heat transfer member and the electrode can be brought into contact with each other by utilizing the space on the opposite side of the driving section with respect to the light emitting element.

[0022] According to the configuration of the fifth aspect, the heat transfer member and the connection portion can be brought into contact with each other by utilizing the space on the opposite side to the extended portion of the electrode.

[0023] According to the configuration of the sixth aspect, the contact width with the heat transfer member can be made wider than in a configuration in which the extended portion of the electrode has the same width as the portion where the light emitting element is arranged.

[0024] According to the seventh aspect of the configuration, heat can be dissipated at a position that does not affect the current path, compared to a configuration in which the direction in which the heat transfer member transfers heat from the electrode to the connection portion is the same as the direction in which current flows between the light-emitting element and the electrode.

[0025] According to the eighth aspect, the heat transfer member has a higher heat dissipation effect of dissipating heat from the light emitting element to the conductive portion, compared to a configuration in which the heat transfer member has the same thermal conductivity as the base material.

[0026] According to the configuration of the ninth aspect, the heat generated in the light emitting element can be dissipated more efficiently than in a configuration in which the heat is transferred only from the electrodes to the base material.

[0027] According to the configuration of the tenth aspect, the object to which heat is transferred and the heat transfer object can be joined to the heat transfer member using a joining material that has affinity with metal, while preventing electrical conduction between the object to which heat is transferred and the heat transfer object.

[0028] According to the configuration of the eleventh aspect, heat from the light emitting element in the light emitting device can be dissipated more efficiently than in a configuration including a light emitting device in which heat generated in the light emitting element is transferred only from the electrode to the base material. [Brief description of the drawings]

[0029] [Figure 1] 1 is a plan view showing a configuration of a light emitting device according to an embodiment of the present invention. [Diagram 2] 1 is a side cross-sectional view showing a configuration of a light emitting device according to an embodiment of the present invention. [Diagram 3] FIG. 11 is a plan view showing a configuration of a light emitting device according to a first modified example. [Figure 4]FIG. 11 is a plan view showing a configuration of a light emitting device according to a second modified example. [Diagram 5] FIG. 11 is a side cross-sectional view showing another application example of the heat transfer member. [Figure 6] 1 is a schematic diagram showing a configuration of an optical measurement device to which a light emitting device according to an embodiment of the present invention is applied DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings.

[0031] (Light emitting device 10) First, the configuration of the light emitting device 10 according to this embodiment will be described. Fig. 1 is a plan view showing the configuration of the light emitting device 10 according to this embodiment. Fig. 2 is a side cross-sectional view showing the configuration of the light emitting device 10 according to this embodiment.

[0032] In the following description, the +X, -X, +Y, and -Y directions are indicated by arrows in the drawings. The +X and -X directions, and the +Y and -Y directions are intersecting directions (specifically, perpendicular directions).

[0033] The light emitting device 10 shown in Fig. 1 and Fig. 2 is a device that emits light, that is, a device that emits light. Specifically, the light emitting device 10 includes a substrate 20, a light emitting element 40, a cathode pattern 30, a driving element 60, a connection pattern 72, and a heat transfer member 80, as shown in Fig. 1 and Fig. 2. The light emitting device 10 also includes anode patterns 52, 54, ground patterns 53, 55, and capacitors 56, 58, as shown in Fig. 1. The cathode pattern 30, the connection pattern 72, the anode patterns 52, 54, and the ground patterns 53, 55 are wiring patterns formed on the surface 20A of the substrate 20.

[0034] The substrate 20 shown in Figs. 1 and 2 is an example of a "base material". Specifically, the substrate 20 is composed of a printed circuit board with a multi-layer structure using an insulator such as glass epoxy resin. Inside the substrate 20, as shown in Fig. 2, a ground 22 is arranged as an inner layer. The ground 22 has a reference potential (i.e., a reference potential of 0V (zero volts)) in a circuit that operates the light-emitting element 40. The ground 22 is an example of a "conductive portion".

[0035] The cathode pattern 30 shown in Figures 1 and 2 is an example of an "electrode". The cathode pattern 30 is formed on the surface 20A of the substrate 20, as shown in Figures 1 and 2. The surface 20A of the substrate 20 is one surface of the substrate 20. In this embodiment, the upper surface in Figure 2 is the surface 20A.

[0036] Furthermore, the cathode pattern 30 is electrically connected to the cathode side electrode of the light-emitting element 40. The cathode pattern 30 is electrically connected to the cathode side electrode of the light-emitting element 40, thereby constituting a part of the cathode side electrode of the light-emitting element 40.

[0037] The light emitting element 40 is disposed on the surface 30A of the cathode pattern 30 as shown in Fig. 1 and Fig. 2. The light emitting element 40 is a part that generates light to be emitted to the outside of the light emitting device 10, and is configured, for example, using a vertical cavity surface emitting laser (VCSEL: Vertical Cavity Surface Emitting Laser) in which light emitting points are arranged two-dimensionally. Furthermore, the light emitting element 40 is configured, for example, as a light emitting section having a thyristor structure that functions as a switch that selectively turns on and off the light emitting points. The light emitting element 40 may be configured as a light emitting section that does not have a thyristor structure.

[0038] 1, the anode pattern 52 is formed on the surface 20A of the substrate 20 on the +Y direction side with respect to the light emitting element 40 and on the +Y direction side with respect to the cathode pattern 30. The anode pattern 54 is formed on the surface 20A of the substrate 20 on the -Y direction side with respect to the light emitting element 40 and on the -Y direction side with respect to the cathode pattern 30. Each of the anode patterns 52, 54 is electrically connected to the anode side electrode of the light emitting element 40 by wire bonding using a plurality of wires 51. The anode patterns 52, 54 are electrically connected to one terminal of the power source 50.

[0039] The ground pattern 53 is formed on the +Y direction side of the anode pattern 52 on the front surface 20A of the substrate 20. The ground pattern 55 is formed on the -Y direction side of the anode pattern 54 on the front surface 20A of the substrate 20. Each of the ground patterns 53, 55 is electrically connected to the ground 22 by a plurality of vias 57, 59 that penetrate the substrate 20 from the front surface 20A to the ground 22.

[0040] The capacitor 56 is a capacitive element, and is provided across the anode pattern 52 and the ground pattern 53. The capacitor 56 is electrically connected to each of the anode pattern 52 and the ground pattern 53.

[0041] The capacitor 58 is a capacitive element, and is provided across the anode pattern 54 and the ground pattern 55. The capacitor 58 is electrically connected to each of the anode pattern 54 and the ground pattern 55. An electric charge is supplied to each of the capacitors 56, 58 from the power source 50 via each of the anode patterns 52, 54, and the electric charge is accumulated therein. Then, the electric charge accumulated in the capacitors 56, 58 is supplied to the light-emitting element 40.

[0042] The cathode pattern 30 extends toward the +X direction side with respect to the light emitting element 40. The end portion of the cathode pattern 30 on the +X direction side serves as a connection portion 36 that is connected to the driving element 60, as will be described later.

[0043] The driving element 60 is an example of a "driving section." The driving element 60 is an element that drives the light-emitting element 40 to emit light, and is configured, for example, with a semiconductor integrated circuit. In this embodiment, the driving element 60 is disposed on the +X direction side of the light-emitting element 40, and is electrically connected to the connection portion 36 of the cathode pattern 30 via a connection terminal 62. The +X direction side is an example of a "side in one direction along the surface of the substrate."

[0044] A ground pad 18 is formed on the front surface 20A of the substrate 20 on the +X direction side of the connection portion 36. The ground pad 18 is electrically connected to the ground 22 by a plurality of vias 19 that penetrate the substrate 20 from the front surface 20A to the ground 22. Furthermore, the ground pad 18 is connected to a terminal (not shown) for connecting the driving element 60 to the ground 22.

[0045] Moreover, the cathode pattern 30 extends in the -X direction relative to the light-emitting element 40. Therefore, the cathode pattern 30 has an extension portion 43 that extends in the -X direction relative to the light-emitting element 40. The -X direction side is the opposite side to the driving element 60 relative to the light-emitting element 40.

[0046] Specifically, the extension portion 43 is disposed on the -X direction side of the anode patterns 52 and 54, and has a width in the -Y direction wider than an arrangement portion 45 in which the light emitting element 40 is arranged in the cathode pattern 30. The -Y direction is an example of a "crossing direction that crosses the opposite direction."

[0047] (Structure for thermally connecting cathode pattern 30 to ground 22) Here, a description will be given of a structure (hereinafter, referred to as a connection structure) for thermally connecting the cathode pattern 30 to the ground 22. Note that thermal connection refers to a connection such that heat is transferred between connection objects.

[0048] The connection structure has a function of transferring heat generated in the light emitting element 40 to the ground 22. Specifically, in this embodiment, the connection structure includes a connection pattern 72, a plurality of vias 73, and a heat transfer member 80.

[0049] 1 and 2, the connection pattern 72 is disposed at a position separated from the cathode pattern 30 on the front surface 20A of the substrate 20. Specifically, the connection pattern 72 is disposed on the -X direction side of the extension portion 43 of the cathode pattern 30 with a gap between the connection pattern 72 and the cathode pattern 30. The multiple vias 73 penetrate from the connection pattern 72 to the ground 22, and electrically and thermally connect the connection pattern 72 and the ground 22. As a result, the multiple vias 73 transfer heat from the connection pattern 72 to the ground 22.

[0050] The heat transfer member 80 is a member that transfers heat from the cathode pattern 30 to the connection pattern 72. This heat transfer member 80 is made of a high thermal conductivity insulator. Specifically, for example, ceramics such as aluminum nitride are used as the heat transfer member 80. More specifically, the heat transfer member 80 is a member having a higher thermal conductivity than the substrate 20. Specifically, the heat transfer member 80 is formed of a material having a higher thermal conductivity than the substrate 20. In this embodiment, high thermal conductivity refers to a value of 10 [W / mK] or more. In this embodiment, an insulator refers to a material having a volume resistivity of 10 13 This refers to a structure with a dielectric constant of 0.1Ω cm or more.

[0051] 2, the heat transfer member 80 is formed in a block shape (i.e., a rectangular parallelepiped shape) and has a contact surface 82 along the surface 20A of the substrate 20. This contact surface 82 contacts the surface 30A of the cathode pattern 30 (specifically, the surface 43A of the extension portion 43) and the surface 72A of the connection pattern 72. Specifically, the heat transfer member 80 is disposed toward the -X direction side from the extension portion 43, and the contact surface 82 contacts the connection pattern 72 on the -X direction side relative to the extension portion 43. As a result, the heat transfer member 80 transfers heat from the extension portion 43 of the cathode pattern 30 to the connection pattern 72.

[0052] In the contact surface 82 of the heat transfer member 80, a contact portion 82A with the surface 30A of the cathode pattern 30 and a contact portion 82B with the surface 72A of the connection pattern 72 are metallized in a state in which they are electrically isolated from each other. Here, metallization refers to forming a metal film on a non-metallic surface. Specifically, the metal film is formed on the surface of the heat transfer member 80 by a deposition method such as chemical vapor deposition (CVD) and physical vapor deposition (PVD). For example, a metal material such as aluminum or copper is used for the metal film. Each of the contact portion 82A and the contact portion 82B is bonded to each of the surface 30A of the cathode pattern 30 and the surface 72A of the connection pattern 72 by a bonding material 89 that has an affinity for metal. For example, a metal material such as solder and silver paste is used as the bonding material 89.

[0053] In heat transfer member 80, heat is transferred from contact portion 82A to contact portion 82B through the insulator portion, so contact portion 82A can be considered as a contact portion that contacts a heat transfer target from which heat is transferred. On the other hand, contact portion 82B can be considered as a contact portion that contacts a heat transfer target to which heat is transferred. Contact portion 82A is an example of a "first contact portion." Contact portion 82B is an example of a "second contact portion."

[0054] In this embodiment, the direction in which the heat transfer member 80 transfers heat from the cathode pattern 30 to the connection pattern 72 is different from the direction in which current flows between the light emitting element 40 and the cathode pattern 30. Specifically, the contact surface 82 of the heat transfer member 80 is in contact with the surface 30A of the cathode pattern 30 and the surface 72A of the connection pattern 72, and the heat transfer member 80 transfers heat from the cathode pattern 30 to the connection pattern 72 along the contact surface 82. Therefore, the heat transfer member 80 transfers heat in the -X direction. The light emitting element 40 is in contact with the surface 30A of the cathode pattern 30 at the bottom surface 40B, and current flows between the light emitting element 40 and the cathode pattern 30 in a direction perpendicular to the substrate 20. Thus, in this embodiment, the heat transfer direction in the heat transfer member 80 is different from the direction in which current flows between the light emitting element 40 and the cathode pattern 30.

[0055] As described above, since the heat transfer member 80 is made of a high thermal conductivity insulator, the cathode pattern 30 and the connection pattern 72 are thermally connected but electrically separated from each other. The electrically separated state refers to a non-conductive state in which there is no conduction between the separated members and no electricity flows between them.

[0056] (Application example of the light emitting device 10) The light emitting device 10 can be applied to an optical measurement device 100 shown in Fig. 6, for example. The optical measurement device 100 shown in Fig. 6 includes the above-mentioned light emitting device 10, a light receiving unit 102, and a processing unit 104. In the optical measurement device 100, an object 103 is placed facing the light emitting device 10 and the light receiving unit 102. In Fig. 6, the object 103 is a person, for example. Fig. 6 is also a schematic view of the optical measurement device 100 viewed from above.

[0057] As an example, the light emitting device 10 irradiates the object 103 with light that spreads two-dimensionally, as shown by the solid line in Fig. 6. The light receiving unit 102 receives reflected light from the object 103 irradiated with light from the light emitting device 10, as shown by the dashed line in Fig. 6. As an example, an imaging device that receives light from two-dimensional directions is used as the light receiving unit 102.

[0058] The processing unit 104 is configured as a computer having an input / output unit for inputting and outputting data, for example. The processing unit 104 measures the distance from the light emitting device 10 to the object 103, or the shape of the object 103. Specifically, the processing unit 104 operates as follows.

[0059] The processing unit 104 controls the light emitting device 10 to emit light from the light emitting device 10 for a short period of time. That is, the light emitting device 10 emits light in a pulsed manner. Then, the processing unit 104 calculates the optical path length from when the light is emitted from the light emitting device 10, reflected by the object 103, to when it reaches the light receiving unit 102, based on the time difference between when the light emitting device 10 emits light and when the light receiving unit 102 receives the reflected light from the object 103. The positions of the light emitting device 10 and the light receiving unit 102 and the interval between them are predetermined. Therefore, the processing unit 104 measures the distance from the light emitting device 10 and the light receiving unit 102, or the distance from a reference point (hereinafter referred to as a reference point) to the object 103. The reference point is a point (point) provided at a predetermined position from the light emitting device 10 and the light receiving unit 102.

[0060] This method is a surveying method based on the arrival time of light, and is called the time-of-flight (TOF) method. If this method is performed on multiple points on the object 103, the three-dimensional shape of the object 103 is measured. As described above, the light from the light-emitting device 10 spreads two-dimensionally and is irradiated onto the object 103. Then, the reflected light from the part of the object 103 that is close to the light-emitting device 10 is incident on the light-receiving unit 102 first. When using an imaging device that acquires the above-mentioned two-dimensional image, a bright spot is recorded in the frame image at the part where the reflected light reaches. From the bright spots recorded in a series of multiple frame images, the optical path length is calculated for each bright spot. Then, the distance from the light-emitting device 10 and the light-receiving unit 102 or the distance from the reference point is calculated. That is, the three-dimensional shape of the object 103 is calculated.

[0061] As another method, the light emitting device 10 of this embodiment may be used for a light measurement method using a structured light method. The light measurement device used is almost the same as the light measurement device 100 shown in FIG. 6 using the light emitting device 10. The difference is that the light pattern irradiated to the object 103 is an innumerable light dots (random pattern), which are received by the light receiving unit 102. The processing unit 104 then processes information related to the light. Here, the processing method does not involve calculating the time difference as described above, but rather calculates the amount of positional deviation of the innumerable light dots to calculate the distance to the object 103 and the three-dimensional shape of the object 103.

[0062] The optical measurement device 100 as described above can be applied to calculating the distance to an article. The optical measurement device 100 can also be applied to identifying an article by calculating the shape of the article. The optical measurement device 100 can also be applied to identifying a person's face (face recognition) by calculating the shape of the face. Furthermore, the optical measurement device 100 can be applied to detecting obstacles in front, behind, or to the sides by being loaded onto a vehicle. In this way, the optical measurement device 100 can be widely used to calculate distance, shape, and the like.

[0063] The light emitting device 10 is not limited to the optical measurement device 100 described above, and can be applied to various devices. For example, the light emitting device 10 may be combined with an optical transmission path and a light receiving means for optical transmission, or may be applied to biological detection in which light emitted from the light emitting device 10 enters the inside of a detection target.

[0064] (Action according to this embodiment) In this embodiment, heat generated in the light emitting element 40 is transferred from the light emitting element 40 through the cathode pattern 30, the extension portion 43, the heat transfer member 80, the connection pattern 72, the via 73, and the ground 22 in this order, and is dissipated to the ground 22. Note that a small amount of heat generated in the light emitting element 40 is also transferred from the cathode pattern 30 to the substrate 20.

[0065] As described above, in this embodiment, the heat generated in the light emitting element 40 is transferred to the ground 22 through the heat transfer member 80, the connection pattern 72, the vias 73, etc., so that the heat of the light emitting element 40 is dissipated more efficiently than in a configuration in which the heat generated in the light emitting element 40 is transferred only from the cathode pattern 30 to the substrate 20. Therefore, according to this embodiment, the degree of temperature drop per unit time in the light emitting element 40 is greater than in a configuration in which the heat generated in the light emitting element 40 is transferred only from the cathode pattern 30 to the substrate 20. As a result, the light emitting element 40 can be driven with high output and a high duty ratio.

[0066] In addition, in this embodiment, since the heat transfer member 80 is made of an insulator, electrical conduction between the cathode pattern 30 and the connection pattern 72 is suppressed compared to a configuration in which the heat transfer member 80 is a conductor. This maintains a state in which the cathode pattern 30 and the ground 22 are electrically isolated from each other.

[0067] In the present embodiment, the heat transfer member 80 is metallized on the contact surface 82 such that a contact portion 82A with the surface 30A of the cathode pattern 30 and a contact portion 82B with the surface 72A of the connection pattern 72 are electrically isolated from each other. Therefore, as in the present embodiment, it is possible to bond each of the cathode pattern 30 and the connection pattern 72 to the heat transfer member 80 using a bonding material 89 that has an affinity for metal.

[0068] In this embodiment, the contact surface 82 of the heat transfer member 80 is in contact with the extension portion 43 that extends in the opposite direction to the driving element 60 for the light emitting element 40. Therefore, the heat transfer member 80 and the cathode pattern 30 are in contact with each other by utilizing the space on the opposite side to the driving element 60 for the light emitting element 40. Therefore, the dead space on the opposite side to the driving element 60 for the light emitting element is effectively utilized.

[0069] Moreover, in this embodiment, the heat transfer member 80 is disposed from the extension portion 43 toward the -X direction side, and the contact surface 82 is in contact with the connection pattern 72 on the -X direction side of the extension portion 43. Therefore, the heat transfer member 80 and the contact surface 82 are in contact with each other by utilizing the space on the -X direction side of the extension portion 43. Therefore, the dead space on the -X direction side of the extension portion 43 is effectively utilized.

[0070] In this embodiment, the extension portion 43 is wider in the -Y direction than the arrangement portion 45 in the cathode pattern 30 where the light emitting element 40 is arranged. Therefore, the contact width with the heat transfer member 80 is wider than in a configuration in which the extension portion 43 has the same width as the arrangement portion 45. As a result, the heat of the light emitting element 40 is efficiently dissipated.

[0071] In the present embodiment, the contact surface 82 of the heat transfer member 80 is in contact with the surface 30A of the cathode pattern 30 and the surface 72A of the connection pattern 72, and the heat transfer member 80 transfers heat from the cathode pattern 30 to the connection pattern 72 along the contact surface 82. Therefore, the heat transfer member 80 transfers heat in the -X direction. Therefore, the direction in which the heat transfer member 80 transfers heat from the cathode pattern 30 to the connection pattern 72 is different from the direction in which the current flows between the light emitting element 40 and the cathode pattern 30. Therefore, compared to a configuration in which the direction in which the heat transfer member 80 transfers heat from the cathode pattern 30 to the connection pattern 72 is the same as the direction in which the current flows between the light emitting element 40 and the cathode pattern 30, it is possible to dissipate heat at a position that does not affect the current path.

[0072] Moreover, in this embodiment, the heat transfer member 80 has a higher thermal conductivity than the substrate 20. Therefore, compared to a configuration in which the heat transfer member 80 has the same thermal conductivity as the substrate 20, the heat dissipation effect of dissipating heat from the light emitting element 40 to the ground 22 is higher.

[0073] Furthermore, according to the heat transfer member 80 of this embodiment, it is possible to join the heat transfer target and the heat transfer target to the heat transfer member using a bonding material that has affinity with metal, while suppressing electrical conduction between the cathode pattern 30, which is the target of heat transfer, and the connection pattern 72, which is the target of heat transfer.

[0074] (First Modification of Cathode Pattern 30) In this embodiment, the cathode pattern 30 is used as an example of an electrode, but is not limited thereto. As an example of an electrode, for example, an anode pattern 52 may be used as shown in Fig. 3. The configuration shown in Fig. 3 will be described below. Note that parts having the same functions as those in the configuration shown in Figs. 1 and 2 described above are appropriately designated by the same reference numerals and their description will be omitted.

[0075] 3, the light-emitting element 40 is disposed on a surface 52A of an anode pattern 52 formed on a surface 20A of a substrate 20. The anode pattern 52 is electrically connected to an anode-side electrode of the light-emitting element 40, thereby forming a part of the anode-side electrode of the light-emitting element 40.

[0076] The ground pattern 53 is formed on the front surface 20A of the substrate 20 on the +Y direction side of the light emitting element 40 and on the +Y direction side of the anode pattern 52. The capacitor 56 is provided across the anode pattern 52 and the ground pattern 53. The capacitor 56 is electrically connected to each of the anode pattern 52 and the ground pattern 53.

[0077] The ground pattern 55 is formed on the front surface 20A of the substrate 20 on the -Y direction side of the light emitting element 40 and on the -Y direction side of the anode pattern 52. The capacitor 58 is provided across the anode pattern 52 and the ground pattern 55. The capacitor 58 is electrically connected to each of the anode pattern 52 and the ground pattern 55.

[0078] The cathode pattern 30 is formed on the front surface 20A of the substrate 20 on the +X direction side of the light emitting element 40 and on the +X direction side of the anode pattern 52. The cathode pattern 30 is electrically connected to the cathode side electrode of the light emitting element 40 by wire bonding using a plurality of wires 51.

[0079] An end portion of the cathode pattern 30 on the +X direction side is a connection portion 36 connected to the driving element 60. The driving element 60 is disposed on the +X direction side of the light emitting element 40, and is electrically connected to the connection portion 36 of the cathode pattern 30 via a connection terminal 62. The ground pad 18 is formed on the front surface 20A of the substrate 20 on the +X direction side of the connection portion 36.

[0080] 3, the heat transfer member 80 contacts the surface 52A of the anode pattern 52 and the surface 72A of the connection pattern 72. As a result, the heat transfer member 80 transfers heat from the anode pattern 52 to the connection pattern 72.

[0081] (Second Modification of Cathode Pattern 30) As an example of the electrode, an anode pattern 52 as shown in Fig. 4 may be used. The configuration shown in Fig. 4 will be described below. Note that parts having the same functions as those in the configuration shown in Fig. 1 and Fig. 2 are appropriately designated by the same reference numerals and their description will be omitted.

[0082] 4, the light-emitting element 40 is disposed on a surface 52A of an anode pattern 52 formed on a surface 20A of a substrate 20. The anode pattern 52 is electrically connected to an anode-side electrode of the light-emitting element 40, thereby forming a part of the anode-side electrode of the light-emitting element 40.

[0083] The ground pattern 53 is formed on the front surface 20A of the substrate 20 on the +Y direction side of the light emitting element 40 and on the +Y direction side of the anode pattern 52. The capacitor 56 is provided across the anode pattern 52 and the ground pattern 53. The capacitor 56 is electrically connected to each of the anode pattern 52 and the ground pattern 53.

[0084] The cathode pattern 30 is formed on the front surface 20A of the substrate 20 on the -Y direction side of the light emitting element 40 and on the -Y direction side of the anode pattern 52. The cathode pattern 30 is electrically connected to the cathode side electrode of the light emitting element 40 by wire bonding using a plurality of wires 51.

[0085] An end of the cathode pattern 30 on the -Y direction side is a connection portion 36 connected to the drive element 60. The drive element 60 is disposed on the -Y direction side of the light emitting element 40, and is electrically connected to the connection portion 36 of the cathode pattern 30 via a connection terminal 62. The ground pad 18 is formed on the front surface 20A of the substrate 20 on the -Y direction side of the connection portion 36.

[0086] In the configuration shown in FIG. 4, the anode pattern 52 extends in the -X direction relative to the light emitting element 40. Therefore, the anode pattern 52 has an extension portion 43 extending in the -X direction relative to the light emitting element 40. Specifically, the extension portion 43 is disposed on the -X direction side relative to the cathode pattern 30, and has a width in the -Y direction wider than an arrangement portion 45 in the anode pattern 52 where the light emitting element 40 is arranged. Then, the heat transfer member 80 contacts a surface 43A of the extension portion 43 of the anode pattern 52 and a surface 72A of the connection pattern 72. As a result, the heat transfer member 80 transfers heat from the extension portion 43 of the anode pattern 52 to the connection pattern 72.

[0087] (Other application examples of the heat transfer member 80) 5, the heat transfer member 80 may be disposed between the cathode pattern 30 and the ground 22. A specific configuration of the heat transfer member 80 will be described below. Note that the heat transfer member 80 will be referred to as a heat transfer member 80(X) to distinguish it from the above-mentioned heat transfer member 80. Also, descriptions of the same parts as the above-mentioned heat transfer member 80 will be omitted as appropriate.

[0088] As shown in Fig. 5, the heat transfer member 80(X) is specifically disposed between the cathode pattern 30 and the ground 22 at a position below the light emitting element 40. The heat transfer member 80(X) has contact surfaces 82, 84 along the front surface 20A of the substrate 20. Specifically, one surface of the heat transfer member 80(X) (specifically, the upper surface in Fig. 5) is the contact surface 82, and the other surface of the heat transfer member 80(X) (specifically, the lower surface in Fig. 5) is the contact surface 84.

[0089] The contact surface 82 and the contact surface 84 are in contact with the rear surface 30B of the cathode pattern 30 and the front surface 22A of the ground 22, respectively. As a result, the heat transfer member 80(X) transfers heat from the cathode pattern 30 to the ground 22. In this case, heat is transferred from the cathode pattern 30 to the ground 22 without passing through the connection pattern 72 and the via 73. In this case, the heat transfer member 80(X) transfers heat in a direction perpendicular to the substrate 20. Therefore, both the direction of heat transfer in the heat transfer member 80 and the direction in which a current flows between the light emitting element 40 and the cathode pattern 30 are perpendicular to the substrate 20.

[0090] In the heat transfer member 80(X), the contact surface 82 and the contact surface 84 are metallized while being electrically isolated from each other. In the heat transfer member 80(X), heat is transferred from the contact surface 82 to the contact surface 84 through an insulating portion, so the contact surface 82 can be considered as a contact portion that contacts a heat transfer target from which heat is transferred. On the other hand, the contact surface 84B can be considered as a contact portion that contacts a heat transfer target to which heat is transferred. The contact surface 82 is an example of a "first contact portion." The contact surface 84 is an example of a "second contact portion."

[0091] (Other variations) In this embodiment, the substrate 20 is used as an example of the base material, but is not limited thereto. An example of the base material may be, for example, a heat dissipation member provided on the front surface 20A of the substrate 20 and having a higher thermal conductivity than the substrate 20, or a member other than the substrate 20.

[0092] In the present embodiment, the heat transfer member 80 is made of an insulator, but this is not limiting. For example, the heat transfer member 80 may be a conductor. In this case, for example, an insulator is used in at least one of the connection pattern 72 and the via 73, and the cathode pattern 30 and the ground 22 are maintained in an electrically isolated state.

[0093] In addition, in this embodiment, the heat transfer member 80 has a contact surface 82 in which the contact portion 82A with the surface 30A of the cathode pattern 30 and the contact portion 82B with the surface 72A of the connection pattern 72 are each metallized in an electrically isolated state, but this is not limited to this, and a heat transfer member 80 in which the contact surface 82 is not processed may also be used.

[0094] In the present embodiment, the heat transfer member 80 is in contact with the connection pattern 72 formed on the front surface 20A of the substrate 20, but is not limited thereto. For example, the connection pattern 72 may not be formed on the front surface 20A of the substrate 20, and the heat transfer member 80 may be in direct contact with the vias 73, or may be in contact with a member that transfers heat to the ground 22. In a configuration in which the heat transfer member 80 is in contact with the vias 73, the vias 73 function as an example of a "connection portion."

[0095] In the present embodiment, the extension portion 43 extends in the direction opposite to the driving element 60 with respect to the light-emitting element 40, but is not limited to this. The extension portion 43 may be configured to extend in the +Y direction or the -Y direction, for example.

[0096] In the present embodiment, the extension portion 43 is wider in the -Y direction than the arrangement portion 45 in the cathode pattern 30 where the light emitting element 40 is arranged, but this is not limited thereto. For example, the extension portion 43 may be configured to have the same width as the arrangement portion 45.

[0097] In the present embodiment, the direction in which the heat transfer member 80 transfers heat from the cathode pattern 30 to the connection pattern 72 is different from the direction in which the current flows between the light emitting element 40 and the cathode pattern 30, but this is not limited thereto. For example, the direction in which the heat transfer member 80 transfers heat from the cathode pattern 30 to the connection pattern 72 may be the same as the direction in which the current flows between the light emitting element 40 and the cathode pattern 30 (see FIG. 5).

[0098] In this embodiment, the ground 22 is disposed inside the substrate 20 as an inner layer as shown in Fig. 2, but is not limited to this. For example, the ground 22 may be disposed on the rear surface 20B of the substrate 20 (i.e., the surface opposite to the front surface 20A).

[0099] The present invention is not limited to the above-described embodiment, and various modifications, changes, and improvements are possible without departing from the spirit and scope of the present invention. For example, the above-described modified examples may be appropriately combined to form a configuration. [Explanation of symbols]

[0100] 10 Light emitting device 20 Substrate (an example of a base material) 20A surface 22 Ground (an example of a conductive part having a reference potential) 30 Cathode pattern (example of electrode) 30A surface 40 Light emitting element 43 Extension part 60 Drive element (an example of a drive unit) 72 Connection pattern (example of connection part) 72A surface 80 Heat transfer material 82 Contact surface 82A Contact part (an example of the first contact part) 82B Contact part (an example of a second contact part)

Claims

1. A light emitting device, a light receiving unit that receives reflected light from an object irradiated with light from the light emitting device; a processing unit that processes information about the light received by the light receiving unit to measure a distance from the light emitting device to the object or a shape of the object; Equipped with The light emitting device comprises: A substrate; an electrode disposed on a surface of the base material, the electrode having a light emitting device disposed on its surface and electrically connected to the light emitting device; a connection portion disposed at a position spaced apart from the electrode on the surface of the base material and connected to a conductive portion having a reference potential; a heat transfer member having a contact surface along a surface of the base material, the contact surface being in contact with a surface of the electrode and a surface of the connection portion, and transferring heat from the electrode to the connection portion; a driving unit that is disposed on one side of the light emitting element along a surface of the base material and drives the light emitting element; having The electrode extends from the light emitting element in a direction opposite to the driving unit for the light emitting element, the contact surface contacts an extension of the electrode; The connection portion is disposed on the opposite side of the extension portion, The heat transfer member is disposed from the extension portion toward the opposite direction side, and the contact surface is in contact with the connection portion on the opposite direction side relative to the extension portion. Optical measuring device.

2. The heat transfer member is an insulator. The optical measurement device according to claim 1 .

3. The heat transfer member is metallized at the contact surface such that a contact portion with the surface of the electrode and a contact portion with the surface of the connection portion are electrically isolated from each other. The optical measurement device according to claim 2 .

4. The extension portion has a width in a cross direction intersecting with the opposite direction that is wider than a portion in which the light emitting element is arranged. The optical measurement device according to any one of claims 1 to 3.

5. The direction in which the heat transfer member transfers heat from the electrode to the connection portion is different from the direction in which a current flows between the light-emitting element and the electrode. The optical measurement device according to any one of claims 1 to 4.

6. The heat transfer member has a higher thermal conductivity than the base material. The optical measurement device according to any one of claims 1 to 5.

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