Semiconductor device and method for manufacturing a semiconductor device

Abstract

The present disclosure relates to a semiconductor device and the purpose of the present disclosure is to provide a semiconductor device with which electrical connection between a signal line and a wiring pattern can be easily performed. This semiconductor device comprises: a semiconductor module; a stem on which the semiconductor module is mounted and which has a stem protrusion protruding to the same side as the semiconductor module; a bridging substrate disposed on the upper surface of the stem protrusion; a lead pin; and a joining block. The stem is provided with a through hole penetrating from a main surface which has the stem protrusion to a surface opposite the main surface. The lead pin has a lead pin protrusion that passes through the through hole and protrudes to the same side as the stem protrusion. The joining block is soldered to the bridging substrate at a first surface, and is soldered to the lead pin protrusion at a second surface. The bridging substrate and the lead pin are electrically connected via the joining block. The solder used for soldering has a lower melting point than the joining block.

Description

Technical Field

[0001] The present disclosure relates to a semiconductor device and a method for manufacturing a semiconductor device.

Background Art

[0002] Patent Document 1 discloses a semiconductor device as an electronic component mounting package, which includes a wiring substrate having a first surface and a wiring pattern located on the first surface, a second surface intersecting the first surface, a through hole opening on the second surface, a base body having the through hole, a signal line passing through the through hole and having a protruding portion protruding from an opening on the second surface of the through hole, a wiring pattern, and a conductive bonding material that joins the protruding portion of the signal line and the wiring pattern. In that case, the conductive bonding material is configured to cover at least the root portion on the opening side of the protruding portion. Thereby, it is possible to prevent the conductive bonding material from becoming thick and prevent the signal transmission characteristics from deteriorating due to insufficient capacitance at the joint portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the manufacture of the above-described semiconductor device, it is necessary to apply a conductive bonding material between the signal line and the wiring pattern, but there is a problem that it is difficult to apply a paste-like conductive bonding material in a desired amount to a desired location.

[0005] A first object of the present disclosure is to provide a semiconductor device in which an electrical connection between a signal line and a wiring pattern can be easily made in order to solve the above-described problems.

[0006] Furthermore, a second objective of this disclosure is to provide a method for manufacturing a semiconductor device that allows for easy electrical connection between signal lines and wiring patterns. [Means for solving the problem]

[0007] The first aspect of this disclosure is, Semiconductor modules and A stem comprising the aforementioned semiconductor module, a stem projection that protrudes on the same side as the semiconductor module, and a through hole that penetrates from the main surface having the stem projection to the opposite surface of that surface, A bridging substrate is positioned on the upper surface of the stem protrusion, A lead pin having a lead pin projection that passes through the through hole and protrudes on the same side as the stem projection, Joining block and Equipped with, The aforementioned joint block is It has a first side and a second side, The first surface is soldered to the bridging substrate, and the second surface is soldered to the lead pin protrusion, The solder used in the aforementioned solder joint has a lower melting point than the joining block. Preferably, the bridging substrate and the lead pins are electrically connected via the bonding block to form a semiconductor device.

[0008] Furthermore, the second aspect is, A method for manufacturing a semiconductor device that incorporates a semiconductor module, A first supply step involves supplying a first solder between the upper surface of the stem protrusion of the stem and the bridging substrate, The first step of melting the solder, The process of solidifying the first solder to join the stem protrusion and the bridging substrate, The steps include: placing a bonding block on the upper surface of the bridging substrate; A second supply step involves supplying a second solder between the bonding block and the protruding portion of the lead pin, The second step of melting the solder, The process involves solidifying the second solder, joining the bridging substrate and the protruding portion of the lead pin to the bonding block, and electrically connecting the bridging substrate and the lead pin via the bonding block. It is preferable to include it. [Effects of the Invention]

[0009] According to the first and second aspects of this disclosure, a semiconductor device and a method for manufacturing the same can be provided, which allows for easy electrical connection between signal lines and wiring patterns. [Brief explanation of the drawing]

[0010] [Figure 1] This is a top view showing a semiconductor device according to Embodiment 1 of the present disclosure. [Figure 2] This is a cross-sectional view of section AA of the semiconductor device shown in Figure 1. [Figure 3] This is a diagram showing the configuration of a prior art semiconductor device relating to a comparative example of the present disclosure, and is viewed from the same direction as Figure 2. [Figure 4] This figure shows a method for manufacturing a semiconductor device according to Embodiment 1 of the present disclosure, and is viewed from the same direction as Figure 2. [Figure 5] This figure shows a method for manufacturing a semiconductor device according to Embodiment 1 of the present disclosure, and is viewed from the same direction as Figure 2. [Figure 6] This figure shows a method for manufacturing a semiconductor device according to Embodiment 1 of the present disclosure, and is viewed from the same direction as Figure 2. [Figure 7] This figure shows a method for manufacturing a semiconductor device according to Embodiment 1 of the present disclosure, and is viewed from the same direction as Figure 2. [Figure 8] This figure shows a method for manufacturing a semiconductor device according to Embodiment 1 of the present disclosure, and is viewed from the same direction as Figure 2. [Figure 9] This figure shows the configuration of a semiconductor device according to Embodiment 1 of the present disclosure, and is viewed from the same direction as Figure 2. [Figure 10]The figure shows the configuration of a semiconductor device according to Embodiment 2 of the present disclosure, and is a view seen from the same direction as FIG. 2. [Figure 11] The figure shows the configuration of a semiconductor device according to Embodiment 2 of the present disclosure, and is a view seen from the same direction as FIG. 1. [Figure 12] The figure shows the configuration of a semiconductor device according to Embodiment 2 of the present disclosure, and is a view seen from the same direction as FIG. 2. [Figure 13] The figure shows the configuration of a semiconductor device according to Embodiment 2 of the present disclosure, and is a front view of the main surface of the stem. [Figure 14] The figure shows the configuration of a semiconductor device according to Embodiment 2 of the present disclosure, and is a view seen from the same direction as FIG. 2. [Figure 15] The figure shows the configuration of a semiconductor device according to Embodiment 2 of the present disclosure, and is a front view of the main surface of the stem. [Figure 16] The figure shows the configuration of a semiconductor device according to Embodiment 3 of the present disclosure, and is a view seen from the same direction as FIG. 2.

Embodiments for Carrying Out the Invention

[0011] A semiconductor device and a method for manufacturing a semiconductor device according to an embodiment of the present disclosure will be described with reference to the drawings. The same or corresponding components are denoted by the same reference numerals, and repeated description may be omitted.

[0012] Embodiment 1 FIG. 1 is a top view showing a semiconductor device 200 according to Embodiment 1 of the present disclosure. FIG. 2 is a cross-sectional view of the A-A portion of the semiconductor device 200 in FIG. 1. Note that FIGS. 1 and 2 illustrate only the basic constituent parts of the semiconductor device 200, and constituent parts such as PD (Photo Diode), thermistors, capacitors, etc. are not shown. Also, even if a constituent element is described in either the top view or the cross-sectional view of the semiconductor device 200, it may be omitted in the other view if it is unnecessary for the description. This point is common to all the following embodiments.

[0013] The semiconductor device 200 comprises an optical semiconductor module 10, a submount 20, a carrier 30, a thermomodule 40, a bridging substrate 50 having a wiring pattern, a stem 100, and lead pins 120 as signal lines.

[0014] In the following, the top view of Figure 1 will be considered the top surface of the semiconductor device 200 and its components. The opposite side will be considered the back surface of the semiconductor device 200 and the components assembled as the semiconductor device 200. Furthermore, the view from the left (right) side of Figure 1 will be considered the left (right) side of the semiconductor device 200 and the components assembled as the semiconductor device 200. This point is common to all embodiments below.

[0015] The submount 20 is a mounting base to which the optical semiconductor module 10 is bonded by first solder 70 on its upper surface. The carrier 30 is bonded to the back surface of the submount 20 by second solder 80. In addition, the thermomodule 40 is bonded to the right side surface of the submount 20 by first solder 70.

[0016] The stem 100 is joined to the right side of the thermomodule 40 by the first solder 70.

[0017] A stem projection 101 is formed on the main surface 104 of the stem 100, protruding to the same side as the semiconductor module. Furthermore, as shown in the cross-sectional view of Figure 2, on the surface having the stem projection 101, a through hole 102 is provided above the stem projection 101, penetrating the main surface 104 to the opposite surface.

[0018] A bridging substrate 50 is joined to the upper surface of the stem projection 101 of the stem 100 by a first solder 70. A metal block 110 is joined to the upper surface of the bridging substrate 50 by a second solder 80.

[0019] The right side of the metal block 110 is joined to the stem 100 by a lead pin 120 passing through a through hole 102 and a second solder 80.

[0020] In the following sections, we will continue to refer to Figures 1 and 2 and provide a more detailed explanation of each component.

[0021] The optical semiconductor module 10 is an element that performs the conversion of an electrical signal into an optical signal, or the reverse conversion. LDs (Laser Diodes) and PDs (Photo Diodes) are examples of optical semiconductor modules 10. The optical semiconductor module 10 is composed of materials such as InP, GaAs, GaN, InGaAs, Ge, and Si. In this embodiment, an LD containing InP is preferred for the optical semiconductor module 10, but the type and material of the element are not limited. The optical semiconductor module 10 has pad portions formed by Au metallization. These pad portions allow for mechanical and electrical bonding between the optical semiconductor module 10 and the submount 20.

[0022] In this embodiment, the case where there is one optical semiconductor module 10 is shown, but there may be multiple optical semiconductor modules 10. In that case, multiple optical semiconductor modules 10 may be bonded to a single submount 20. This point is common to all the embodiments described below.

[0023] The submount 20 includes a base material 21, an electrode pad 22 formed on the upper or lower surface of the base material 21, and an electrode pad 23 formed on the upper or lower surface of the base material 21 that is different from the electrode pad 22. As the material for the base material 21, a material that is an electrical insulator and has high thermal conductivity in order to effectively cool the optical semiconductor module 10 is preferred, and generally ceramic plates such as AlN and Al2O3 are used.

[0024] In this embodiment, the semiconductor device 200 is shown with one submount 20, but the number of submounts 20 is not limited.

[0025] It is common to use the same material for electrode pads 22 and 23. The optical semiconductor module 10 is joined to electrode pad 22 by the first solder 70. Furthermore, electrode pad 22 is electrically connected to surrounding components and the surface of the optical semiconductor module 10 by wires 60 or the like.

[0026] Since the electrode pad 22 is a wiring member for electrically connecting the optical semiconductor module 10 to an external circuit, a metal with low electrical resistance is preferred. For electrode pads 22 and 23, metallization with Au or the like with a thickness of 3.0 μm or less is commonly used.

[0027] In this embodiment, first, an electrode pad 22 made of Au with a thickness of 1.5 μm is metallized onto a substrate 21 made of AlN with a thickness of 0.3 mm. Furthermore, a first solder 70 containing AuSn with a thickness of 3 μm is pre-coated on the electrode pad 22 at the location where the optical semiconductor module 10 will be bonded. This provides an electrode pad 22 suitable for this embodiment.

[0028] The electrode pads 23, which are installed on the heat dissipation side of the substrate 21, are mechanically and thermally connected to the carrier 30 via solder or Ag paste, etc. In this embodiment, they are connected with a second solder 80 of the SnAgCu system.

[0029] The carrier 30 is made of a material with excellent thermal conductivity, such as a metal or alloy of Ag, Cu, Fe, Al, or an insulator such as a ceramic or resin coated with a metal. In this embodiment, a carrier 30 with Au plating on the surface of CuW is preferred, but is not limited to this.

[0030] The carrier 30 in this embodiment has a convex shape when viewed from above. For the purpose of explanation, the protruding portion of the convex shape is referred to as the protrusion, and the remaining portion is referred to as the bottom. On the carrier 30, the thermomodule 40 is joined to the right side of the bottom by the first solder 70. On the other hand, the submount 20 is joined to the upper surface of the protrusion by the second solder 80. SnAgCu-based second solder 80 is used for joining. Furthermore, the optical semiconductor module 10 is joined to the upper surface of the submount 20. Note that the carrier 30 is not limited to a convex shape and can take other shapes.

[0031] The thermomodule 40 releases the heat it receives to the stem 100, etc., via a Peltier element. By controlling the temperature of the optical semiconductor module 10 with the thermomodule 40, it becomes possible to operate the optical semiconductor module 10 stably. Metallized surface 41 is formed at the junction of the thermomodule 40 with the carrier 30, and metallized surface 42 is formed at the junction of the thermomodule 40 with the stem 100. It is common to use the same material for metallized surfaces 41 and 42. For metallized surfaces 41 and 42, materials such as Au with a thickness of about 3.0 μm are used.

[0032] The bridging substrate 50 is joined to the stem projection 101 of the stem 100 by the first solder 70. The bridging substrate 50 has a base material 51, an electrode pad 52 formed on the upper surface of the base material 51, and an electrode pad 53 formed on the back surface of the base material 51. The base material 51 is preferably an electrical insulator, and generally a ceramic plate such as AlN or Al2O3 is used. The bridging substrate 50 drives the optical semiconductor module 10 with a high-frequency electrical signal, or outputs a high-frequency signal output from the optical semiconductor module 10 to lead pins 120 that are electrically connected via a metal block 110.

[0033] It is common to use the same material for electrode pads 52 and 53. Electrode pad 52, which is positioned on the circuit side of the bridging substrate 50, is joined to the metal block 110 by a second solder 80. A joint portion, such as a wire 60, is formed on electrode pad 52, and this joint portion electrically connects it to electrode pad 22 of the submount 20. Since electrode pad 52 is a wiring component, a metal with low electrical resistance is preferred, similar to electrode pad 22. For electrode pads 52 and 53, metallization with Au or the like with a thickness of 3.0 μm or less is commonly used. In this embodiment, a bridging substrate 50 is preferred in which electrode pads 52 made of 1.0 μm thick Au are metallized on a base material 51 made of Al2O3 with a thickness of 0.5 mm, but the invention is not limited to this.

[0034] The electrode pad 53 is joined to the upper surface of the stem projection 101. In this embodiment, the joining is shown using the first solder 70, but joining may also be done via a conductive bonding material such as Ag paste.

[0035] The wire 60 electrically connects, for example, the electrode pad 52 formed on the upper surface of the bridging substrate 50 and the electrode pad 22 formed on the submount 20. The connection is made, for example, by an ultrasonic method. The wire 60 also electrically connects the stem protrusion 101 and the carrier 30, the bridging substrate 50 and the submount 20, and the lead pins 120 (excluding the lead pins 120 joined to the metal block 110) and the thermomodule 40, etc. Note that the connections made by the wire 60 are not limited to these.

[0036] For the wire 60, a metal with low electrical resistance is preferred. Therefore, metals such as Au, Cu, Al, or alloys thereof are generally used.

[0037] The first solder 70 is used to join the electrode pads 22 of the submount 20 and the optical semiconductor module 10. At the time the joining is performed using the first solder 70, the process of joining the submount 20, which includes the optical semiconductor module 10, to the upper surface of the carrier 30 with the second solder 80 (referred to as the carrier-mount joining process) has not yet been performed. From this perspective, the material of the first solder 70 is preferably a metal that has a higher melting point and higher thermal conductivity than the second solder 80. This makes it possible to prevent the first solder 70 from remelting during the carrier-mount joining process. Note that the joining location using the first solder 70 is not limited to between the electrode pads 22 of the submount 20 and the optical semiconductor module 10.

[0038] As the first solder 70, alloys containing Au, Sn, Pb, Ag, Cu, Zn, Ni, Sb, In, Ge, Si, etc., with a melting point of less than 450°C are generally used. In this embodiment, it is preferable to use an alloy mainly containing Au, Sn, Ge, or Si, with a melting point of 250°C or higher, as the first solder 70. In this embodiment, a eutectic solder of Au and Sn is particularly preferred for the first solder 70, but is not limited thereto.

[0039] The second solder 80 is used, for example, in the carrier-mount bonding process. As described above, at the time of the carrier-mount bonding process, the optical semiconductor module 10 and the submount 20 are already bonded by the first solder 70. Therefore, as the material for the second solder 80, a metal with a lower melting point than the first solder 70 and high thermal conductivity is preferred.

[0040] As the second solder 80, alloys containing Sn, Pb, Ag, Cu, Zn, Ni, Sb, Bi, In, Ge, etc., with a melting point of less than 450°C are generally used. In this embodiment, it is preferable to use an alloy mainly containing Sn, Ag, or Cu, with a melting point of 200°C or higher, as the second solder 80. In this embodiment, a solder containing Sn, Ag, and Cu is particularly preferred for the second solder 80, but is not limited to this.

[0041] It should be noted that the application examples of the first solder 70 and the second solder 80 described in this embodiment are merely examples, and the second solder 80 may be applied to the locations indicated as the first solder 70 in the drawings, or vice versa. Furthermore, the first solder 70 and the second solder 80 may be the same.

[0042] The insulating adhesive 90 adheres the lead pin 120, which passes through the through hole 102 provided in the stem 100, to the inner wall of the through hole 102. Considering that a lens cap will be joined to the stem 100 in the final step and the inside of the lens cap will be sealed, care must be taken to prevent the adhesive from peeling off and destroying the airtight seal when, for example, the stem 100 and the thermomodule 40 are joined by the first solder 70. From this viewpoint, the insulating adhesive 90 is preferably made of a material with high heat resistance and a small expansion and contraction rate.

[0043] Furthermore, since the stem 100 and the lead pin 120 need to be electrically insulated, the material of the insulating adhesive 90 is preferably an insulating material. In this embodiment, glass is preferred for the insulating adhesive 90, but it is not limited to this.

[0044] The stem 100 is, for example, a cylindrical plate, and a stem projection 101 is formed on the main surface 104 of the stem 100, projecting to the same side as the semiconductor module. Furthermore, as shown in the cross-sectional view of Figure 2, on the surface having the stem projection 101, a through hole 102 is provided above the stem projection 101, penetrating the main surface 104 to the opposite surface.

[0045] The stem projection 101 is formed to protrude further towards the optical semiconductor module 10 than the projection of the lead pin 120. The stem projection 101 may be formed by mechanically joining a different material from the stem 100 with solder or the like, but since the bridging substrate 50 is joined to the upper surface of the stem projection 101 by the first solder 70, it is preferable that it be formed integrally with the stem 100. The stem 100 is formed, for example, by metallizing the surface of an inexpensive and easily processed metal with Au. In this embodiment, SPC material (cold-rolled steel sheet) is preferred for the stem projection 101, but is not limited thereto.

[0046] The metal block 110 is made of a material with excellent electrical conductivity, such as a metal or alloy of metals such as Ag, Cu, Fe, or Al, or a material in which a metal coating is applied to an electrical insulator such as ceramic or resin. In this embodiment, a metal block 110 in which Au plating is applied to the surface of a CuW block is preferred, but is not limited thereto. A bridging substrate 50 is joined to the back surface of the metal block 110 via electrode pads 52 and second solder 80. In addition, lead pins 120 are joined to the right side surface of the metal block 110 by second solder 80.

[0047] Hereafter, the surface of the metal block 110 that is soldered to the bridging substrate 50 will be referred to as the first surface 105, and the surface of the metal block 110 that is soldered to the lead pin protrusions 121 will be referred to as the second surface 106. Note that the first surface 105 and the second surface 106 do not necessarily have to be perpendicular; they may be parallel or the same surface.

[0048] In this embodiment, the metal block 110 is preferably a cube or a rectangular prism. However, the metal block 110 may be of other shapes.

[0049] The lead pin 120 is a signal line made of a material with excellent electrical conductivity, such as a metal or alloy of metal, Ag, Cu, Fe, Al, Ni, or an insulator such as ceramic or resin coated with metal. The lead pin 120 is cylindrical or rectangular. In this embodiment, the lead pin 120 is preferably a cylinder with a diameter of 0.3 mm and a length of 8 mm, with the surface of Fe-50Ni plated with Au, but is not limited to this.

[0050] As described above, one of the multiple lead pins 120 has a lead pin projection 121 that passes through a through hole 102 formed in the stem 100 and protrudes on the same side as the stem projection 101. Furthermore, the lead pin 120 is joined to the metal block 110 with a second solder 80 at the end face 122 of the lead pin projection 121. However, the joining does not necessarily have to be at the end face 122 of the lead pin projection 121, but may be at the side. If two or more of the multiple lead pins 120 are to be joined to the metal block 110, multiple through holes 102 can be provided, and the lead pins 120 can be passed through each of the multiple through holes 102 and electrically connected to the metal block 110.

[0051] <Comparative Example> Figure 3 is a diagram showing the configuration of a prior art semiconductor device 300 relating to a comparative example of the present disclosure, and is viewed from the same direction as Figure 2. As shown in Figure 3, in the prior art semiconductor device 300, the lead pins 120 and electrode pads 52 are directly joined by a conductive bonding material such as the first solder 70. Because there is a distance between the lead pins 120 and the bridging substrate 50, the distance of the conductive bonding material joining them is long.

[0052] Furthermore, since the lead pins 120 are fixed to the stem 100 by being bonded with insulating adhesive 90, there is a large misalignment of the lead pin protrusions 121 between individual units. In the conventional technology, it is necessary to establish a manufacturing process that takes this misalignment into account when joining the lead pins 120 to the bridging substrate 50.

[0053] <Effects of Embodiment 1 of this Disclosure> On the other hand, as shown in Figure 2, in this embodiment, the lead pin 120 and the electrode pad 52 are joined via a metal block 110. This allows the cross-sectional area when current flows between the lead pin 120 and the bridging substrate 50 to be larger compared to the conventional technology. As a result, it is possible to reduce the electrical resistance between the lead pin 120 and the bridging substrate 50 compared to the conventional technology, thereby preventing deterioration of the signal transmission characteristics. Furthermore, by using a metal with lower electrical resistance than the first solder 70 as the metal block 110, the above effects can be further enhanced.

[0054] Furthermore, in this embodiment, during the manufacturing of the semiconductor device 200, the upper surface of the metal block 110, which is not joined to either the lead pin 120 or the electrode pad 52, can be attracted by a collet and easily placed in a position where it contacts both the end face 122 of the lead pin 120 and the electrode pad 52. In addition, by using the metal block 110, it becomes unnecessary to manage the application location and amount of conductive bonding material, as in the conventional technology in which the lead pin 120 and the electrode pad 52 are directly joined by conductive bonding, thereby simplifying manufacturing.

[0055] Furthermore, in this embodiment, by making the surface area of ​​the metal block 110 that is joined to the lead pin 120 larger than the amount of misalignment of the lead pin protrusion 121, the misalignment of the lead pin protrusion 121 can be absorbed by the metal block 110. This eliminates the need to establish a manufacturing process that takes into account variations in the amount of misalignment of the lead pin protrusion 121, as in the conventional technology, and contributes to improved yield.

[0056] The following describes the manufacturing method of the semiconductor device 200 in this embodiment, with reference to Figures 4 to 8. Figure 4 is a diagram showing the manufacturing method of the semiconductor device 200 according to Embodiment 1 of this disclosure, and is viewed from the same direction as Figure 2. First, a plate-shaped first solder 70 is supplied to the upper surface of the stem projection 101 formed on the stem 100 (first step). Furthermore, the first solder 70 is melted by heating the surface of the stem 100 opposite to the main surface 104 with a heater 150 (second step). In the second step, an additional step may be added to melt the second solder 80 that has been previously supplied to the end face 122 of the lead pin 120.

[0057] Next, Figure 5 shows a method for manufacturing a semiconductor device 200 according to Embodiment 1 of the present disclosure, and is viewed from the same direction as Figure 2. With the first solder 70 on the upper surface of the stem projection 101 molten, the bridging substrate 50 is placed on it using the mounting machine 160 (third step). Furthermore, the first solder 70 is solidified by cooling the entire stem 100 (fourth step). This joins the stem projection 101 and the bridging substrate 50. The set temperature of the heater 150 when melting the first solder 70 is, for example, 360°C.

[0058] Furthermore, the third and fourth steps may be performed either before or after the step of joining the thermomodule 40 to the stem 100 with the first solder 70, but it is preferable to perform them beforehand.

[0059] Figure 6 is a diagram showing a method for manufacturing a semiconductor device 200 according to Embodiment 1 of the present disclosure, and is viewed from the same direction as Figure 2. A plate-shaped second solder 80 is supplied onto the electrode pad 52 of the bridging substrate 50, and the second solder 80 is melted by heating the surface of the stem 100 opposite the main surface 104 with a heater 150 (fifth step).

[0060] Figure 7 shows a method for manufacturing a semiconductor device 200 according to Embodiment 1 of the present disclosure, and is viewed from the same direction as Figure 2. With the second solder 80 on the electrode pad 52 molten, a metal block 110 is placed on top and the metal block 110 is scrubbed with a scrubbing machine 170 (sixth step). In the sixth step, the stem 100 is heated, and the metal block 110 is heated and scrubbed via the bridging substrate 50. The scrubbing direction includes at least the longitudinal direction of the lead pin 120, so that the second solder 80 on the electrode pad 52 also diffuses to the end face 122 of the lead pin 120.

[0061] It should be noted that the second solder 80 supplied in the first step has an oxide film on its surface when it melts. The oxide film can be removed by scrubbing the metal block 110. Using flux eliminates the need for scrubbing, but since flux adhering to the surrounding area after soldering will require cleaning, scrubbing is preferable.

[0062] Figure 8 shows a method for manufacturing a semiconductor device 200 according to Embodiment 1 of the present disclosure, and is viewed from the same direction as Figure 2. The lead pins 120 are heated by heating the stem 100 with the metal block 110 in contact with the end face 122 of the lead pins 120 (seventh step). Finally, the second solder 80 is solidified by cooling the entire stem 100 with the positions of the metal block 110 and the lead pins 120 fixed (eighth step). This allows the metal block 110 to be soldered to both the electrode pad 52 and the lead pins 120. As a result, the bridging substrate 50 and the lead pins 120 can be electrically connected via the metal block 110.

[0063] Furthermore, since the sixth step can remove the oxide film formed on the surface of the second solder 80, it is preferable to perform the sixth and seventh steps simultaneously with the carrier-mount bonding step described above in order to simplify the process.

[0064] Furthermore, the third step of joining the aforementioned bridging substrate 50 to the stem projection 101 of the stem 100 can also be included within the carrier-mount joining step by changing the first solder 70 to the second solder 80. However, in this case, the second solder 80 solidified in the third step will be remelted in the sixth step, so care must be taken to prevent the bridging substrate 50 from shifting position when the metal block 110 is scrubbed. The set temperature of the heater 150 when melting the second solder 80 is, for example, 300°C, but is not limited to this.

[0065] In the conventional technology relating to the comparative example shown in Figure 3, when soldering the lead pin 120 and the bridging substrate 50, the lead pin 120 is heated to a temperature at which soldering is possible. However, at this time, the lead pin 120 is fixed to the stem 100 by the insulating adhesive 90. Therefore, in the conventional technology, it is effectively necessary to heat the stem 100 and then heat the lead pin 120 via the insulating adhesive 90. However, since the thermal conductivity of the insulating adhesive 90 is small compared to metals, etc., it is necessary to heat the stem 100 to a temperature higher than the temperature at which the first solder 70 normally melts, or to heat the stem 100 for a longer time than the time it normally takes for the first solder 70 to melt.

[0066] On the other hand, in this embodiment, by heating the stem 100 with the metal block 110 in contact with the end face 122 of the lead pin 120 in the seventh step, it becomes possible to heat the lead pin 120 indirectly from the stem 100 via the bridging substrate 50. Since the bridging substrate 50 and the metal block 110 generally have a higher thermal conductivity than the insulating adhesive 90, it becomes possible to heat the lead pin 120 at a lower temperature and faster than in the conventional technique of heating the lead pin 120 from the stem 100 via the insulating adhesive 90. This makes it possible to shorten the time required for product assembly.

[0067] Furthermore, in the conventional technology shown in Figure 3, when joining the lead pin 120 and the bridging substrate 50 with the first solder 70, it is common to prevent oxidation of the first solder 70 by using the first solder 70 with a surface coated with Au, or by joining under a reducing atmosphere such as nitrogen. In the conventional technology, it was difficult to use the second solder 80, which is even more susceptible to oxidation than the first solder 70, and it was necessary to use the first solder 70, which has a higher melting point than the second solder 80. When heating the lead pin 120, it was necessary to control the temperature to prevent the solder at other joint areas from remelting and causing displacement of the components at the joint area, and to prevent the insulating adhesive 90 filled in the through hole 102 of the stem 100 from peeling off and destroying the airtight seal.

[0068] On the other hand, in this embodiment, the surface oxide film of the solder can be destroyed by scrubbing in the sixth step, making it possible to use a second solder 80 that is easily oxidized. As a result, the heating temperature can be lowered compared to the conventional technique using the first solder 70, and temperature control becomes unnecessary.

[0069] Furthermore, the second solder 80 supplied in the fifth step must have a lower melting point than the metal block 110 so as not to melt the metal block 110 during heating. This point is also true when the first solder 70 is used instead of the second solder 80. This point is also true in all of the following embodiments.

[0070] As described above, this embodiment provides a semiconductor device 200 and a method for manufacturing the same, which allows for easy electrical connection between lead pins 120 as signal lines and bridging substrates 50 as wiring patterns.

[0071] <Variations> Although the above example uses a semiconductor device 200 equipped with an optical semiconductor module 10, it can also be applied to power semiconductor devices and the like.

[0072] In the first step, it was explained that a plate-shaped first solder 70 is supplied to the upper surface of the stem projection 101 formed on the stem 100, but the method of supplying the first solder 70 is not limited to this. For example, the first solder 70 may be applied in advance to the electrode pads 53 of the bridging substrate.

[0073] Similarly, in the fifth step, a plate-shaped second solder 80 is supplied onto the electrode pads 52 of the bridging substrate 50, and in the sixth step, the metal block 110 is scrubbed to diffuse the second solder 80 onto the end faces 122 of the lead pins 120. However, the method of supplying the second solder 80 is not limited to this. For example, the second solder 80 may be pre-applied to the lead pin protrusions 121. In this case, it becomes unnecessary to scrub the metal block 110 in the sixth step.

[0074] Figure 9 is a diagram showing the configuration of a semiconductor device 200 according to Embodiment 1 of the present disclosure, and is viewed from the same direction as Figure 2. In the metal block 110, the second solder 80 is applied to all surfaces except the top surface which is held in place by the collet during transport. By applying the second solder 80 to the metal block 110 in advance by plating or the like, it becomes unnecessary to supply the second solder 80 to the bridging substrate 50 in the fifth step. Furthermore, in the sixth step, it becomes unnecessary to scrub the metal block 110 and diffuse the second solder 80 to the end face 122 of the lead pin 120.

[0075] Note that, as shown in Figure 9, it is not necessary for the second solder 80 to be applied to all surfaces except the top surface; it is sufficient if it is applied to the surface of the metal block 110 on the electrode pad 52 side and the surface on the lead pin 120 side. Also, the second solder 80 that joins the metal block 110 and the lead pin 120 and the second solder 80 that joins the metal block 110 and the electrode pad 52 may be a single unit.

[0076] Embodiment 2 Figure 10 is a diagram showing the configuration of a semiconductor device 200 according to Embodiment 2 of the present disclosure, and is viewed from the same direction as Figure 2. Figure 11 is a diagram showing the configuration of a semiconductor device 200 according to Embodiment 2 of the present disclosure, and is viewed from the same direction as Figure 1. One or more notches or depressions are formed in the vertical direction of the paper on the surface of the metal block 110 on the lead pin 120 side. As a result, when the second solder 80 on the bridging substrate 50 is melted in the sixth step, the molten second solder 80 crawls up into the notches or depressions by capillary action and fills them, spreading between the metal block 110 and the lead pin 120. As a result, soldering becomes possible without supplying the second solder 80 to the lead pin 120.

[0077] Figure 12 is a diagram showing the configuration of a semiconductor device 200 according to Embodiment 2 of the present disclosure, and is viewed from the same direction as Figure 2. Figure 13 is a diagram showing the configuration of a semiconductor device 200 according to Embodiment 2 of the present disclosure, and is a front view of the main surface 104 of the stem 100. The metal block 110 is provided with a block through-hole 111 that penetrates from the surface on the lead pin 120 side in the direction of extension of the lead pin 120. Furthermore, the lead pin protrusion 121 passes through the block through-hole 111 and is joined to the second surface 106 of the metal block 110 by a second solder 80 within the block through-hole 111. This increases the stability of the members during joining and ensures reliable solder joining. Furthermore, since the joining area between the lead pin 120 and the metal block 110 can be made larger compared to Embodiment 1, the electrical resistance can be reduced and the deterioration of transmission characteristics can be suppressed.

[0078] Furthermore, the shape of the block through-hole 111 is not limited to a cylindrical shape. For example, the diameter of the side of the metal block 110 facing the lead pin 120 may be made larger than the diameter of the opposing side, resulting in a tapered shape. This is preferable because it allows for adjustment of the lead pin 120 within the block through-hole 111.

[0079] Figure 14 is a diagram showing the configuration of a semiconductor device 200 according to Embodiment 2 of the present disclosure, and is viewed from the same direction as Figure 2. Figure 15 is a diagram showing the configuration of a semiconductor device 200 according to Embodiment 2 of the present disclosure, and is a front view of the main surface 104 of the stem 100. A recess 112 is provided on the metal block 110 from the surface on the lead pin 120 side toward the opposite surface. The lead pin protrusion 121 is inserted into the recess 112 and joined to the second surface 106 of the metal block 110 by the second solder 80 within the recess 112. This provides the same effects as those described in Figures 12 and 13.

[0080] Furthermore, in the recessed portion 112, the diameter on the opening side may be made larger than the diameter of the opposing surface, creating a tapered shape. This is preferable because it allows for adjustment of the lead pin 120 within the recessed portion 112.

[0081] Embodiment 3 Figure 16 is a diagram showing the configuration of a semiconductor device 200 according to Embodiment 3 of the present disclosure, and is viewed from the same direction as Figure 2. In this embodiment, the metal block 110 described in Embodiment 1 is replaced with a substrate 130.

[0082] The base material 130 comprises a base material 131, a first electrode pad 132 formed on the back surface of the base material 131, and a second electrode pad 133 formed on a surface perpendicular to the back surface of the base material 131. The base material 131 is an electrical insulator, and generally, ceramic plates such as AlN or Al2O3 are used.

[0083] It is common to use the same material for the first electrode pad 132 and the second electrode pad 133. The first electrode pad 132 is joined to the electrode pad 52 by the second solder 80. The surface on the first electrode pad 132 on which this joining takes place is the first surface 105 described in Embodiment 1.

[0084] Furthermore, the first electrode pad 132 and the second electrode pad 133 are electrically connected, for example, by metallizing the second electrode pad 133. Since the first electrode pad 132 is a wiring member that electrically connects the lead pin 120 and the electrode pad 52, a metal with low electrical resistance is preferred. For the first electrode pad 132 and the second electrode pad 133, metallization with Au or the like with a thickness of 3.0 μm or less is generally used. By forming the first electrode pad 132 and the second electrode pad 133 in a state where they are electrically connected by side metallization or the like, a decrease in transmission characteristics between the lead pin 120 and the electrode pad 52 can be prevented.

[0085] In this embodiment, the substrate 130 is configured such that a first electrode pad 132 made of Au with a thickness of 3.0 μm is placed on a base material 131 made of AlN with a thickness of 0.5 mm. Furthermore, a second solder 80 containing SuAgCu with a thickness of 5 μm is pre-coated onto the first electrode pad 132, and a suitable substrate 130 is obtained by sputtering a layer of Au with a thickness of 0.1 μm onto the surface of the second solder 80. However, the configuration of the substrate 130 is not limited to this.

[0086] The second electrode pad 133 is joined to the end face 122 of the lead pin 120 by the second solder 80. However, the joining does not necessarily have to be on the end face 122 of the lead pin projection 121, but may be on the side. The surface on the second electrode pad 133 on which the joining is performed is the second surface 106 described in Embodiment 1.

[0087] For bonding, a second solder 80 with Au sputtered onto its surface, similar to the first electrode pad 132, is preferred. By pre-coating the first electrode pad 132 and the second electrode pad 133 with the second solder 80 with Au sputtered onto its surface, surface oxidation of the second solder 80 can be prevented, and the step of supplying the second solder 80 can be omitted. Alternatively, the second solder 80 with Au sputtered onto its surface may be pre-coated onto the bridging substrate 50 side and the lead pin 120 side of the metal block 110 described in Embodiment 1. This will provide the same effects as described above.

[0088] In this embodiment, when electrically connecting multiple lead pins 120 to the bridging substrate 50, in the first embodiment, it is necessary to arrange the same number of metal blocks 110 as the number of lead pins 120 that are joined to the metal block 110. On the other hand, in the base material 130 of this embodiment, by forming the first electrode pad 132 and the second electrode pad 133 to match the arrangement of the multiple lead pins 120, it is possible to join all the lead pins 120 to the electrode pads 52 using a single base material 130. This reduces the time required for assembly and suppresses the increase in processing costs. Note that the method of joining multiple lead pins 120 to the bridging substrate 50 is not limited to this, and multiple base materials 130 may be used.

[0089] In this embodiment, the case in which the second electrode pad 133 is formed on a surface perpendicular to the back surface of the base material 131 has been described. However, the second electrode pad 133 may be on the same surface as the surface on which the first electrode pad 132 is formed, or it may be on the upper surface of the base material 131.

[0090] This disclosure is not limited to the embodiments described above, and various modifications are possible during implementation without departing from its essence. Furthermore, each embodiment may be combined as appropriate, and the combined effects can be obtained.

[0091] <Correspondence for use in claims> The metal block 110 described in Embodiment 1 and the base material 130 described in Embodiment 2 are referred to as joining blocks in the claims. [Explanation of Symbols]

[0092] 10 Optical semiconductor module, 20 Submount, 21 Substrate, 22 Electrode pad, 23 Electrode pad, 30 Carrier, 40 Thermomodule, 41 Metallization, 42 Metallization, 50 Bridging substrate, 51 Substrate, 52 Electrode pad, 53 Electrode pad, 60 Wire, 70 First solder, 80 Second solder, 90 Insulating adhesive, 100 Stem, 101 Stem protrusion, 102 Through hole, 104 Main surface, 105 First surface, 106 Second surface, 110 Metal block, 111 Block through hole, 112 Recess, 120 Lead pin, 121 Lead pin protrusion, 122 End face, 130 Substrate, 131 Base material, 132 First electrode pad, 133 Second electrode pad, 150 Heater, 160 Mounting machine, 170 Scrub machines, 200 semiconductor devices, 300 conventional semiconductor devices

Claims

1. Semiconductor modules and A stem comprising the aforementioned semiconductor module, a stem projection that protrudes on the same side as the semiconductor module, and a through hole that penetrates from the main surface having the stem projection to the opposite surface of that surface, A bridging substrate is positioned on the upper surface of the stem protrusion, A lead pin having a lead pin projection that passes through the through hole and protrudes on the same side as the stem projection, Joining block and Equipped with, The aforementioned joint block is It has a first side and a second side, The first surface is soldered to the bridging substrate, and the second surface is soldered to the lead pin protrusion, The solder used in the aforementioned solder joint has a lower melting point than the aforementioned joint block. A semiconductor device in which the bridging substrate and the lead pins are electrically connected via the bonding block.

2. The semiconductor device according to claim 1, wherein the bonding block is a metal or a block in which a metal is coated on an electrical insulator.

3. The aforementioned joint block is An insulating base material, A first electrode pad formed on the base material, A second electrode pad electrically connected to the first electrode pad, A base material comprising, On the first surface, the first electrode pad and the bridging substrate are soldered together. The semiconductor device according to claim 1, wherein the second electrode pad and the lead pin protrusion are solder-joined to the second surface.

4. The semiconductor device according to any one of claims 1 to 3, wherein the bonding block is bonded to the end face or side surface of the lead pin projection on the second surface.

5. The semiconductor device according to any one of claims 1 to 3, further comprising a notch or recess filled with solder on the second surface of the bonding block.

6. The second surface of the joining block is the inner wall of a block through-hole that penetrates the joining block in the direction of extension of the lead pin, The semiconductor device according to claim 1 or 2, wherein the lead pin protrusion passes through the block through-hole and is soldered to the joining block within the block through-hole.

7. The second surface of the joining block is the inner wall of the recessed portion of the joining block, The semiconductor device according to claim 1 or 2, wherein the lead pin protrusion passes through the opening of the recess and is soldered to the bonding block within the recess.

8. The semiconductor device according to claim 1 or 2, wherein the electrical resistance of the bonding block is smaller than the electrical resistance of the solder.

9. A method for manufacturing a semiconductor device that incorporates a semiconductor module, A first supply step involves supplying a first solder between the upper surface of the stem protrusion of the stem and the bridging substrate, The first step of melting the solder, The process involves solidifying the first solder to join the stem protrusion and the bridging substrate, The steps include: placing a bonding block on the upper surface of the bridging substrate; A second supply step involves supplying a second solder between the bonding block and the protruding portion of the lead pin, The second step of melting solder, The process involves solidifying the second solder, joining the bridging substrate and the protruding portion of the lead pin to the bonding block, and electrically connecting the bridging substrate and the lead pin via the bonding block. A method for manufacturing a semiconductor device, including the method described above.

10. The method for manufacturing a semiconductor device according to claim 9, wherein the melting point of the first solder is higher than the melting point of the second solder.

11. The method for manufacturing a semiconductor device according to claim 9, wherein the first solder and the second solder are the same.

12. The method for manufacturing a semiconductor device according to any one of claims 9 to 11, wherein the first supply step includes a step of supplying the first solder to the upper surface of the stem protrusion.

13. The second supply process is as follows: The steps include supplying the second solder to the upper surface of the bridging substrate, The steps include scrubbing the bonding block and diffusing the second solder supplied onto the bridging substrate between the bonding block and the protruding portion of the lead pin, A method for manufacturing a semiconductor device according to any one of claims 9 to 11, including

14. The method for manufacturing a semiconductor device according to any one of claims 9 to 11, wherein the second supply step includes a step of applying the second solder to the protruding portion of the lead pin.

15. In the bonding block, the surface to which the bridging substrate is bonded is designated as the first surface, and the surface to which the protruding portion of the lead pin is bonded is designated as the second surface. The method for manufacturing a semiconductor device according to any one of claims 9 to 11, wherein the second supply step includes a step of applying the second solder to the surface of the bonding block, including the first surface and the second surface.

16. The method for manufacturing a semiconductor device according to claim 13, further comprising the step of sputtering Au onto the surface of the supplied second solder in the second supply step.

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