Semiconductor device and method for manufacturing 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

Semiconductor device and method for manufacturing the same

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

[0002] Patent Document 1 discloses a semiconductor device as a package for mounting electronic elements, which includes a wiring board having a first surface and a wiring pattern located on the first surface, a base having a second surface intersecting the first surface and a through hole opening in the second surface, a signal line passing through the through hole and having a protruding portion protruding from the opening in the second surface of the through hole, and a conductive adhesive material bonding the wiring pattern to the protruding portion of the signal line. The conductive adhesive material is configured to cover at least the root portion of the protruding portion on the opening side. This prevents the conductive adhesive material from becoming thick and prevents degradation of signal transmission characteristics at the joint due to insufficient capacitance.

[0003] Japanese Patent Application Laid-Open No. 2021-153156

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

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

[0006] A second object of the present disclosure is to provide a method for manufacturing a semiconductor device that allows easy electrical connection between signal lines and wiring patterns.

[0007] A first aspect of the present disclosure is a semiconductor device comprising: a semiconductor module; a stem having the semiconductor module mounted thereon and including a stem protrusion protruding on the same side as the semiconductor module and a through hole penetrating from a main surface having the stem protrusion to an opposite surface; a bridging substrate disposed on an upper surface of the stem protrusion; a lead pin having a lead pin protrusion that passes through the through hole and protrudes on the same side as the stem protrusion; and a bonding block, wherein the bonding block has a first surface and a second surface, is solder-bonded to the bridging substrate on the first surface, and is solder-bonded to the lead pin protrusion on the second surface, and the solder used for the solder bonding has a lower melting point than the bonding block, and the bridging substrate and the lead pin are electrically connected via the bonding block.

[0008] A second aspect is a method for manufacturing a semiconductor device equipped with a semiconductor module, and preferably includes the following steps: a first supplying step of supplying first solder between an upper surface of a stem protrusion of a stem and a bridging substrate; a step of melting the first solder; a step of solidifying the first solder to join the stem protrusion and the bridging substrate; a step of placing a bonding block on the upper surface of the bridging substrate; a second supplying step of supplying second solder between the bonding block and the protrusion of a lead pin; a step of melting the second solder; and a step of solidifying the second solder to join the bridging substrate and the protrusion of the lead pin to the bonding block, respectively, and electrically connecting the bridging substrate and the lead pin via the bonding block.

[0009] According to the first and second aspects of the present disclosure, it is possible to provide a semiconductor device and a manufacturing method thereof that allow easy electrical connection between a signal line and a wiring pattern.

[0010] 1 is a top view showing a semiconductor device according to a first embodiment of the present disclosure; FIG. 2 is a cross-sectional view of the A-A portion of the semiconductor device of FIG. 1; FIG. 3 is a view showing the configuration of a semiconductor device of a conventional technology according to a comparative example of the present disclosure, viewed from the same direction as FIG. 2; FIG. 4 is a view showing a method for manufacturing a semiconductor device according to a first embodiment of the present disclosure, viewed from the same direction as FIG. 2; FIG. 5 is a view showing a method for manufacturing a semiconductor device according to a first embodiment of the present disclosure, viewed from the same direction as FIG. 2; FIG. 6 is a view showing a method for manufacturing a semiconductor device according to a first embodiment of the present disclosure, viewed from the same direction as FIG. 2; FIG. 7 is a view showing a method for manufacturing a semiconductor device according to a first embodiment of the present disclosure, viewed from the same direction as FIG. 2; FIG. 8 is a view showing a method for manufacturing a semiconductor device according to a first embodiment of the present disclosure, viewed from the same direction as FIG. 2; FIG. 9 is a view showing a method for manufacturing a semiconductor device according to a second embodiment of the present disclosure, viewed from the same direction as FIG. 2; FIG. 10 is a view showing a configuration of a semiconductor device according to a second embodiment of the present disclosure, viewed from the same direction as FIG. 1; FIG. 11 is a view showing a configuration of a semiconductor device according to a second embodiment of the present disclosure, viewed from the same direction as FIG. 2; Fig. 1 is a diagram showing the configuration of a semiconductor device according to a second embodiment of the present disclosure, which is a front view of a main surface of a stem; Fig. 2 is a diagram showing the configuration of a semiconductor device according to a second embodiment of the present disclosure, which is a view from the same direction as Fig. 2; Fig. 3 is a diagram showing the configuration of a semiconductor device according to a second embodiment of the present disclosure, which is a front view of a main surface of a stem; Fig. 4 is a diagram showing the configuration of a semiconductor device according to a third embodiment of the present disclosure, which is a view from the same direction as Fig. 2;

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

[0012] First Embodiment FIG. 1 is a top view showing a semiconductor device 200 according to a first embodiment of the present disclosure. FIG. 2 is a cross-sectional view of the semiconductor device 200 taken along the line A-A in FIG. 1. Note that FIGS. 1 and 2 only show the basic components of the semiconductor device 200, and do not show components such as a photodiode (PD), a thermistor, and a capacitor. Furthermore, even if a component is shown 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 not necessary for the explanation. This point is common to all of the following embodiments.

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

[0014] 1 will be referred to as the top surface of the semiconductor device 200 and its components. The opposite surface will be referred to as the back surface of the semiconductor device 200 and the components assembled to form the semiconductor device 200. Furthermore, the surface viewed from the left (right) side of the paper in FIG. 1 will be referred to as the left side (right side) of the semiconductor device 200 and the components assembled to form the semiconductor device 200. This point is common to all of the following embodiments.

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

[0016] A stem 100 is joined to the right side surface of the thermo module 40 by a first solder 70 .

[0017] A stem protrusion 101 that protrudes on the same side as the semiconductor module is formed on a main surface 104 of the stem 100. As shown in the cross-sectional view of Figure 2, on the surface having the stem protrusion 101, a through-hole 102 that penetrates the main surface 104 to the opposing surface is provided above the stem protrusion 101.

[0018] A bridging substrate 50 is joined to the upper surface of the stem protruding portion 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 surface of the metal block 110 is joined to a lead pin 120 passing through the through hole 102 of the stem 100 by a second solder 80 .

[0020] With continued reference to Figures 1 and 2, each component will now be described in more detail.

[0021] The optical semiconductor module 10 is a device that converts electrical signals into optical signals, or vice versa. Examples of optical semiconductor modules 10 include laser diodes (LDs) and photodiodes (PDs). The optical semiconductor module 10 is made of materials such as InP, GaAs, GaN, InGaAs, Ge, and Si. While an InP-containing LD is suitable for the optical semiconductor module 10 of this embodiment, the type and material of the device are not limited. The optical semiconductor module 10 has pads formed with Au metallization. These pads mechanically and electrically bond the optical semiconductor module 10 to the submount 20.

[0022] Although the present embodiment shows a case where the number of optical semiconductor modules 10 is one, there may be a plurality of optical semiconductor modules 10. In this case, a plurality of optical semiconductor modules 10 may be bonded to a single submount 20. This point is common to all of the following embodiments.

[0023] The submount 20 has a substrate 21, electrode pads 22 formed on the upper or lower surface of the substrate 21, and electrode pads 23 formed on the upper or lower surface of the substrate 21 different from the surface on which the electrode pads 22 are formed. The material of the substrate 21 is preferably an electrical insulator and has high thermal conductivity in order to effectively cool the optical semiconductor module 10, and generally a ceramic plate such as AlN or Al2O3 is used.

[0024] Although the semiconductor device 200 of this embodiment has one submount 20, the number of submounts 20 is not limited.

[0025] The same material is generally used for the electrode pads 22 and 23. The optical semiconductor module 10 is joined to the electrode pad 22 with a first solder 70. Furthermore, the electrode pad 22 is electrically connected to the surrounding members and the surface of the optical semiconductor module 10 with wires 60 or the like.

[0026] The electrode pads 22 are wiring members for electrically connecting the optical semiconductor module 10 to an external circuit, and are therefore preferably made of a metal with low electrical resistance. Metallization using Au or the like with a thickness of 3.0 μm or less is generally used for the electrode pads 22 and 23.

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

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

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

[0030] The carrier 30 of this embodiment has a convex shape when viewed from above. For the sake of explanation, the protruding portion of the convex shape will be referred to as the protruding portion, and the remaining portion will be referred to as the bottom portion. In the carrier 30, the thermo module 40 is joined to the right side surface of the bottom portion with a first solder 70. Meanwhile, the submount 20 is joined to the upper surface of the protruding portion with a second solder 80. A SnAgCu-based second solder 80 is used for the 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 have other shapes.

[0031] The thermo module 40 dissipates the received heat to the stem 100 and the like via a Peltier element. Controlling the temperature of the optical semiconductor module 10 with the thermo module 40 enables stable operation of the optical semiconductor module 10. Metallization 41 is formed on the bonding surface of the thermo module 40 with the carrier 30, and metallization 42 is formed on the bonding surface of the thermo module 40 with the stem 100. The same material is generally used for the metallization 41 and the metallization 42. Au or the like having a thickness of about 3.0 μm is used for the metallization 41 and the metallization 42.

[0032] The bridging substrate 50 is joined to the stem protrusion 101 of the stem 100 by a 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 a second electrode pad 53 formed on the back surface of the base material 51. The base material 51 is preferably made of an electrically insulating material, and a ceramic plate such as AlN or Al2O3 is generally 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 a lead pin 120 electrically connected via a metal block 110.

[0033] The electrode pads 52 and 53 are generally made of the same material. The electrode pads 52, which are arranged on the circuit side of the bridging substrate 50, are joined to the metal block 110 by the second solder 80. A joint such as a wire 60 is formed on the electrode pad 52, and the joint is used to electrically connect the electrode pad 52 to the electrode pad 22 on the submount 20. Because the electrode pad 52 is a wiring member, a metal with low electrical resistance, similar to the electrode pad 22 described above, is preferred. Metallization using Au or the like with a thickness of 3.0 μm or less is generally used for the electrode pads 52 and 53. In this embodiment, a bridging substrate 50 in which electrode pads 52 made of Au with a thickness of 1.0 μm are metallized on a substrate 51 made of Al2O3 with a thickness of 0.5 mm is preferred, but the present invention is not limited to this.

[0034] The electrode pad 53 is bonded to the upper surface of the stem protrusion 101. In this embodiment, the electrode pad 53 is bonded using the first solder 70, but the electrode pad 53 may be bonded 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 a method using ultrasonic waves. The wire 60 also electrically connects between the stem protrusion 101 and the carrier 30, between the bridging substrate 50 and the submount 20, and between the lead pins 120 excluding the lead pins 120 bonded to the metal block 110 and the thermo module 40, etc. Note that the points connected by the wire 60 are not limited to these.

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

[0037] The first solder 70 is used to bond the electrode pads 22 of the submount 20 to the optical semiconductor module 10. At the time of the step in which the bonding is performed using the first solder 70, the step of bonding the submount 20 including the optical semiconductor module 10 to the upper surface of the carrier 30 with the second solder 80 (referred to as the carrier-mount bonding step) has not yet been performed. From this perspective, the material of the first solder 70 is preferably a metal with 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 bonding step. Note that the bonding 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] An alloy containing Au, Sn, Pb, Ag, Cu, Zn, Ni, Sb, In, Ge, Si, or the like and having a melting point of less than 450° C. is generally used as the first solder 70. In this embodiment, it is preferable to use an alloy containing mainly Au, Sn, Ge, Si, or the like and having a melting point of 250° C. or higher. Note that, although a eutectic solder of Au and Sn is particularly suitable for the first solder 70 in this embodiment, the present invention is not limited to this.

[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, the material of the second solder 80 is preferably a metal with a lower melting point than the first solder 70 and high thermal conductivity.

[0040] An alloy containing Sn, Pb, Ag, Cu, Zn, Ni, Sb, Bi, In, Ge, or the like and having a melting point of less than 450° C. is generally used as the second solder 80. In this embodiment, it is preferable to use an alloy containing mainly Sn, Ag, or Cu, or the like, and having a melting point of 200° C. or higher. Note that, although a solder containing Sn, Ag, and Cu is particularly suitable for the second solder 80 in this embodiment, the second solder 80 is not limited to this.

[0041] 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 a location shown 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 bonds the lead pin 120, which passes through a through hole 102 provided in the stem 100, to the inner wall of the through hole 102. Considering that a lens cap is bonded to the stem 100 in the final process and the interior of the lens cap is sealed, care must be taken to ensure that the adhesive does not peel off and destroy the airtight seal when, for example, bonding the stem 100 and the thermo module 40 with the first solder 70. From this perspective, the insulating adhesive 90 is preferably made of a material that has 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, it is preferable that the material of the insulating adhesive 90 be an insulating material. Glass is suitable for the insulating adhesive 90 in this embodiment, but the material is not limited to this.

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

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

[0046] The metal block 110 is made of a material with excellent electrical conductivity, such as a metal such as Ag, Cu, Fe, or Al, or an alloy thereof, or even a metal coated on an electrical insulator such as ceramic or resin. In this embodiment, a metal block 110 having a CuW block with Au plating on its surface is suitable, but is not limited to this. A bridging substrate 50 is bonded to the back surface of the metal block 110 via an electrode pad 52 with second solder 80. A lead pin 120 is also bonded to the right side surface of the metal block 110 with the second solder 80.

[0047] Hereinafter, the surface of the metal block 110 soldered to the bridging substrate 50 will be referred to as the first surface 105, and the surface of the metal block 110 soldered to the lead pin protrusion 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 to each other, but may be parallel to each other or on the same surface.

[0048] The metal block 110 of this embodiment is preferably a cube or a rectangular parallelepiped, but may have other shapes.

[0049] The lead pin 120 is a signal line made of a material with excellent electrical conductivity, such as a metal such as Ag, Cu, Fe, Al, or Ni, or an alloy thereof, or an insulator such as ceramic or resin coated with a metal. The lead pin 120 is a cylinder or a rectangular column. 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 plurality of lead pins 120 has a lead pin protrusion 121 that passes through a through hole 102 formed in the stem 100 and protrudes on the same side as the stem protrusion 101. Furthermore, the lead pin 120 is joined to the metal block 110 at an end surface 122 of the lead pin protrusion 121 with the second solder 80. However, the joining does not necessarily have to be to the end surface 122 of the lead pin protrusion 121, but may be to the side surface. Note that when two or more of the plurality of lead pins 120 are joined to the metal block 110, a plurality of through holes 102 may be provided, and the lead pins 120 may be passed through each of the plurality of through holes 102 to be electrically connected to the metal block 110.

[0051] 3 is a diagram showing the configuration of a semiconductor device 300 according to a comparative example of the present disclosure, viewed from the same direction as in FIG. 2. As shown in FIG. 3, in the semiconductor device 300 according to the prior art, the lead pins 120 and the electrode pads 52 are directly bonded together by a conductive bonding material such as a first solder 70. Because the lead pins 120 and the bridging substrate 50 are spaced apart, the distance of the conductive bonding material bonding them together is long.

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

[0053] 2, in this embodiment, the lead pins 120 and the electrode pads 52 are joined via the metal block 110. This allows a larger cross-sectional area for current to flow between the lead pins 120 and the bridging substrate 50 compared to the prior art. As a result, it is possible to reduce the electrical resistance between the lead pins 120 and the bridging substrate 50 compared to the prior art, thereby preventing degradation of signal transmission characteristics. Furthermore, by using a metal with lower electrical resistance than the first solder 70 for the metal block 110, the above-mentioned effects can be further enhanced.

[0054] Furthermore, in this embodiment, during the manufacture 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 surface 122 of the lead pin 120 and the electrode pad 52. Furthermore, by using the metal block 110, it is no longer necessary to manage the location and amount of conductive bonding material to be applied, as is the case with conventional technology in which the lead pin 120 and the electrode pad 52 are directly bonded by conductive bonding, and this simplifies the manufacturing process.

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

[0056] A manufacturing method of the semiconductor device 200 according to the present embodiment will be described below with reference to FIGS. 4 to 8. FIG. 4 is a diagram illustrating the manufacturing method of the semiconductor device 200 according to the first embodiment of the present disclosure, viewed from the same direction as FIG. 2. First, a plate-shaped first solder 70 is supplied to the upper surface of the stem protrusion 101 formed on the stem 100 (first step). Furthermore, the first solder 70 is melted by heating the surface of the stem 100 opposite the main surface 104 with a heater 150 (second step). Note that the second step may include an additional step of melting the second solder 80 previously supplied to the end surface 122 of the lead pin 120.

[0057] 5 is a diagram showing a manufacturing method of the semiconductor device 200 according to the first embodiment of the present disclosure, viewed from the same direction as FIG. 2. With the first solder 70 on the upper surface of the stem protrusion 101 in a melted state, the bridging substrate 50 is placed by the placement machine 160 (third step). Furthermore, the entire stem 100 is cooled to solidify the first solder 70 (fourth step). This bonds the stem protrusion 101 and the bridging substrate 50. The heater 150 is set to a temperature of, for example, 360° C. when melting the first solder 70.

[0058] The third and fourth steps may be carried out either before or after the step of joining the thermo-module 40 to the stem 100 with the first solder 70, but are preferably carried out before.

[0059] 6 is a diagram illustrating a manufacturing method of the semiconductor device 200 according to the first embodiment of the present disclosure, viewed from the same direction as in FIG. 2. A plate-shaped second solder 80 is supplied onto the electrode pad 52 of the bridging substrate 50, and the surface of the stem 100 facing the main surface 104 is heated by a heater 150 to melt the second solder 80 (fifth step).

[0060] 7 is a diagram showing a manufacturing method of a semiconductor device 200 according to the first embodiment of the present disclosure, viewed from the same direction as FIG. 2 . With the second solder 80 on the electrode pad 52 in a molten state, a metal block 110 is placed from above and scrubbed with a scrubbing machine 170 (sixth step). In the sixth step, the stem 100 is heated to scrub the metal block 110 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 surface 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 is melted. The oxide film can be removed by scrubbing the metal block 110. Although scrubbing is not necessary if flux is used, scrubbing is preferable because cleaning is required if the flux adheres to the surrounding area after soldering.

[0062] FIG. 8 is a diagram illustrating a manufacturing method of a semiconductor device 200 according to the first embodiment of the present disclosure, viewed from the same direction as FIG. 2 . The stem 100 is heated while the metal block 110 is in contact with the end face 122 of the lead pin 120, thereby heating the lead pin 120 (seventh step). Finally, the entire stem 100 is cooled while the positions of the metal block 110 and the lead pin 120 are fixed, thereby solidifying the second solder 80 (eighth step). This allows the metal block 110 to be solder-bonded to both the electrode pad 52 and the lead pin 120. As a result, the bridging substrate 50 and the lead pin 120 can be electrically connected via the metal block 110.

[0063] In addition, 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 above-mentioned carrier-mount bonding step in order to simplify the process.

[0064] The third step of joining the bridging substrate 50 to the stem protrusion 101 of the stem 100 can also be included in the carrier-mount joining step by changing the first solder 70 to the second solder 80. In this case, however, 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 scrubbing the metal block 110. 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] 3 , when soldering the lead pins 120 to the bridging substrate 50, the lead pins 120 are heated to a temperature at which soldering is possible, but at that time, the lead pins 120 are fixed to the stem 100 by the insulating adhesive 90. Therefore, in the conventional technology, it is necessary to effectively heat the stem 100 and heat the lead pins 120 via the insulating adhesive 90. However, because the thermal conductivity of the insulating adhesive 90 is lower than that of 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 time longer than the time it takes for the first solder 70 to normally melt.

[0066] On the other hand, in this embodiment, by heating the stem 100 in the seventh step while the metal block 110 is in contact with the end face 122 of the lead pin 120, it becomes possible to heat the lead pin 120 indirectly from the stem 100 via the bridging substrate 50. Because 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 quickly and at a lower temperature than in the conventional technology in which the lead pin 120 is heated from the stem 100 via the insulating adhesive 90. This makes it possible to shorten the time required for product assembly.

[0067] 3 , when joining the lead pin 120 and the bridging substrate 50 with the first solder 70, oxidation of the first solder 70 is generally prevented by using a first solder 70 whose surface is coated with Au or by joining in a reducing atmosphere such as nitrogen. In the prior art, it was difficult to use the second solder 80, which oxidizes more easily than the first solder 70, and it was necessary to use the first solder 70 with a higher melting point than the second solder 80. When heating the lead pin 120, temperature control was required to prevent the solder at other joining sites from remelting, causing the components at those joining sites to shift position, 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 scrubbing in the sixth step can destroy the surface oxide film of the solder, making it possible to use the easily oxidized second solder 80. This allows the heating temperature to be lower than in the prior art that uses the first solder 70, and eliminates the need for temperature control.

[0069] The second solder 80 supplied in the fifth step must have a melting point lower than that of the metal block 110 so as not to melt the metal block 110 when heated. 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, according to this embodiment, it is possible to provide the semiconductor device 200 and its manufacturing method, which allow easy electrical connection between the lead pins 120 as signal lines and the bridging substrate 50 as a wiring pattern.

[0071] <Modifications> In the above description, the semiconductor device 200 including the optical semiconductor module 10 is taken as an example, but the present invention can also be applied to power semiconductor devices and the like.

[0072] In the first step, the plate-shaped first solder 70 is supplied to the upper surface of the stem protrusion 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 to the electrode pads 53 of the bridging substrate in advance.

[0073] Similarly, it has been described that in the fifth step, the plate-shaped second solder 80 is supplied onto the electrode pads 52 of the bridging substrate 50, and further that in the sixth step, the metal block 110 is scrubbed to spread 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 applied to the lead pin protrusions 121 in advance. In this case, there is no need to scrub the metal block 110 in the sixth step.

[0074] 9 is a diagram showing the configuration of a semiconductor device 200 according to the first embodiment of the present disclosure, viewed from the same direction as FIG. 2 . In the metal block 110, the second solder 80 is applied to all surfaces except the top surface, which is attracted by a collet during transportation. By applying the second solder 80 to the metal block 110 in advance by plating or the like, it is not necessary to supply the second solder 80 to the bridging substrate 50 in the fifth step. Furthermore, it is not necessary to scrub the metal block 110 and diffuse the second solder 80 onto the end surfaces 122 of the lead pins 120 in the sixth step.

[0075] 9, the second solder 80 does not need to be applied to all surfaces except the top surface, but only needs to be applied to the surface of the metal block 110 facing the electrode pad 52 and the surface facing the lead pin 120. Furthermore, the second solder 80 joining the metal block 110 and the lead pin 120 and the second solder 80 joining the metal block 110 and the electrode pad 52 may be integrated.

[0076] Second Embodiment FIG. 10 is a diagram showing the configuration of a semiconductor device 200 according to a second embodiment of the present disclosure, viewed from the same direction as FIG. 2 . FIG. 11 is a diagram showing the configuration of a semiconductor device 200 according to a second embodiment of the present disclosure, viewed from the same direction as FIG. 1 . One or more notches or recesses are formed in the vertical direction of the page on the surface of the metal block 110 facing the lead pins 120. As a result, when the second solder 80 on the bridging substrate 50 is melted in the sixth step, the molten second solder 80 creeps up and fills the notches or recesses by capillary action, and spreads between the metal block 110 and the lead pins 120. As a result, solder bonding is possible without supplying the second solder 80 to the lead pins 120.

[0077] FIG. 12 is a diagram showing the configuration of a semiconductor device 200 according to a second embodiment of the present disclosure, viewed from the same direction as FIG. 2 . FIG. 13 is a diagram showing the configuration of a semiconductor device 200 according to the second embodiment of the present disclosure, and is a front view of the main surface 104 of the stem 100. A block through-hole 111 is provided through the metal block 110 from the surface on the lead pin 120 side in the extension direction 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 within the block through-hole 111 by the second solder 80. This increases the stability of the components during joining and ensures reliable solder joining. Furthermore, the joining area between the lead pin 120 and the metal block 110 can be made larger than in the first embodiment, thereby reducing electrical resistance and suppressing deterioration of transmission characteristics.

[0078] The shape of the block through-hole 111 is not limited to a cylindrical shape, and may be tapered, for example, by making the diameter of the surface of the metal block 110 facing the lead pin 120 larger than the diameter of the opposing surface. This is preferable because it allows for adjustment of the lead pin 120 within the block through-hole 111.

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

[0080] The diameter of the opening of the recess 112 may be larger than the diameter of the opposing surface, forming a tapered shape. This is preferable because it allows for an adjustment margin for the lead pin 120 within the recess 112.

[0081] 16 is a diagram showing the configuration of a semiconductor device 200 according to a third embodiment of the present disclosure, viewed from the same direction as in FIG. 2. In this embodiment, the metal block 110 described in the first embodiment is changed to a substrate 130.

[0082] The substrate 130 includes 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 a ceramic plate made of AlN, Al2O3, or the like is used.

[0083] The same material is generally used 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 of the first electrode pad 132 where this joining is performed is the first surface 105 described in the first embodiment.

[0084] Furthermore, the first electrode pad 132 and the second electrode pad 133 are electrically connected by, for example, metallizing the second electrode pad 133. Because 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 preferable. For the first electrode pad 132 and the second electrode pad 133, metallization using 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, it is possible to prevent a deterioration in the transmission characteristics between the lead pin 120 and the electrode pad 52.

[0085] In the base material 130 of this embodiment, a first electrode pad 132 made of Au and having a thickness of 3.0 μm is disposed on a base material 131 made of AlN and having a thickness of 0.5 mm. Furthermore, a second solder 80 containing SuAgCu and having a thickness of 5 μm is pre-coated on the first electrode pad 132, and Au having a thickness of 0.1 μm is sputtered onto the surface of the second solder 80, thereby obtaining a suitable base material 130. However, the configuration of the base material 130 is not limited to this.

[0086] The second electrode pad 133 is joined to the end surface 122 of the lead pin 120 by the second solder 80. However, the joining does not necessarily have to be to the end surface 122 of the lead pin protrusion 121, but may be to the side surface. The surface of the second electrode pad 133 where the joining is performed is the second surface 106 described in the first embodiment.

[0087] For bonding, second solder 80 having Au sputtered onto its surface, similar to first electrode pad 132, is preferred. By pre-coating first electrode pad 132 and second electrode pad 133 with second solder 80 having Au sputtered onto its surface, surface oxidation of second solder 80 can be prevented, and the step of supplying second solder 80 can be omitted. Note that second solder 80 having Au sputtered onto its surface may also be pre-coated on the surface of metal block 110 described in embodiment 1 that faces bridging substrate 50 and the surface that faces lead pin 120. This can achieve the same effect as described above.

[0088] Here, when electrically connecting a plurality of lead pins 120 to the bridging substrate 50, in the case of the first embodiment, it is necessary to arrange the same number of lead pins 120 as the number of lead pins 120 to be joined to the metal block 110. On the other hand, in the base material 130 of this embodiment, by forming the first electrode pads 132 and the second electrode pads 133 in accordance with the arrangement of the plurality of lead pins 120, it becomes possible to join all of the lead pins 120 to the electrode pads 52 with a single base material 130. This shortens the time required for assembly and suppresses increases in processing costs. Note that the method of joining a plurality of lead pins 120 to the bridging substrate 50 is not limited to this, and a plurality of base materials 130 may also be used.

[0089] In this embodiment, the second electrode pad 133 is formed on a surface perpendicular to the rear surface of the base material 131. 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 on the upper surface of the base material 131.

[0090] The present disclosure is not limited to the above-described embodiments, and various modifications can be made in the implementation stage without departing from the spirit of the present disclosure. Furthermore, the embodiments may be implemented in appropriate combinations, and in such cases, the combined effects can be obtained.

[0091] <Correspondence to Use in Claims> The metal block 110 described in the first embodiment and the base material 130 described in the second embodiment are referred to as joint blocks in the claims.

[0092] REFERENCE SIGNS LIST 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 Depression, 120 Lead pin, 121 Lead pin protrusion, 122 End surface, 130 Substrate, 131 Base material, 132 First electrode pad, 133 Second electrode pad, 150 Heater, 160 Mounting machine, 170 Scrubber, 200 Semiconductor device, 300 Prior art semiconductor device

Claims

1. a semiconductor module; a stem on which the semiconductor module is mounted, the stem having a stem protruding portion protruding on the same side as the semiconductor module, and a through-hole penetrating from a main surface having the stem protruding portion to a surface opposite the main surface; a bridge substrate disposed on an upper surface of the stem protrusion; a lead pin having a lead pin protrusion that passes through the through hole and protrudes on the same side as the stem protrusion; A joining block; Equipped with The joining block is having a first surface and a second surface; the first surface is soldered to the bridge substrate, and the second surface is soldered to the lead pin protrusion; The solder used for the solder joint has a melting point lower than that of the joint block, The bridging substrate and the lead pins are electrically connected via the joining block.

2. 2. The semiconductor device according to claim 1, wherein said junction block is a metal or a block of an electrical insulator coated with a metal.

3. The joining 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 substrate comprising: the first electrode pad and the bridge substrate are solder-bonded on the first surface; The semiconductor device according to claim 1 , wherein the second electrode pad and the lead pin protrusion are soldered together on the second surface.

4. The semiconductor device according to claim 1 , wherein the second surface of the joining block is joined to an end face or a side face of the lead pin protrusion.

5. The semiconductor device according to claim 1 , further comprising a notch or a recessed portion on the second surface of the joining block, the notch or recessed portion being filled with the solder.

6. the second surface of the joining block is an inner wall of a block through-hole that penetrates the joining block in an extending direction of the lead pin, 3. The semiconductor device according to claim 1, 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 joint block is an inner wall of a recessed portion of the joint block, 3. The semiconductor device according to claim 1, wherein said lead pin protrusions pass through openings of said recesses and are soldered to said joining blocks within said recesses.

8. 3. The semiconductor device according to claim 1, wherein the electrical resistance of said joint block is smaller than the electrical resistance of said solder.

9. A method for manufacturing a semiconductor device including a semiconductor module, a first supplying step of supplying a first solder between an upper surface of a stem protrusion of the stem and the bridge substrate; melting the first solder; solidifying the first solder to join the stem protrusion and the bridge substrate; placing a bonding block on top of the bridging substrate; a second supplying step of supplying a second solder between the joining block and the protruding portion of the lead pin; melting the second solder; solidifying the second solder to bond the bridge substrate and the protruding portions of the lead pins to the bonding block, and electrically connecting the bridge substrate and the lead pins via the bonding block; A method for manufacturing a semiconductor device, comprising:

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

12. 12. The method for manufacturing a semiconductor device according to claim 9, wherein the first supplying step includes the step of supplying the first solder to an upper surface of the stem protrusion.

13. The second supplying step applying the second solder to an upper surface of the bridge substrate; scrubbing the bonding block to allow the second solder applied on the bridge substrate to diffuse between the bonding block and the protruding portions of the lead pins; 12. The method for manufacturing a semiconductor device according to claim 9, comprising:

14. 12. The method for manufacturing a semiconductor device according to claim 9, wherein the second supplying step includes a step of applying the second solder to the protruding portion of the lead pin.

15. a surface of the bonding block to which the bridging substrate is bonded is defined as a first surface, and a surface of the bonding block to which the protruding portions of the lead pins are bonded is defined as a second surface; 12. The method for manufacturing a semiconductor device according to claim 9, wherein the second supplying step includes a step of applying the second solder to a surface of the joining block including the first surface and the second surface.

16. 14. The method for manufacturing a semiconductor device according to claim 13, wherein the second supplying step further comprises the step of sputtering Au onto a surface of the supplied second solder.