Semiconductor module

Abstract

The purpose of the present invention is to improve adhesion between a bonding portion of a metal wiring board and a sealing resin in a semiconductor module. A semiconductor module (1) is provided with: a laminated substrate (2) in which a plurality of circuit boards (22) are arranged on the upper surface of an insulating plate (20); a semiconductor element (3) disposed on the upper surface of the at least one circuit board; and a metal wiring board (4) disposed on the upper surface of the semiconductor element. The metal wiring board has a bonding portion (40) that is bonded to the upper surface of the semiconductor element via a bonding material (S3). The joining portion includes a plate-like portion having an upper surface and a lower surface, the plate-like portion having a plurality of roughened recesses roughening the upper surface, the plurality of roughened recesses including a plurality of types of roughened recesses (49a, 49b, 49c, 49d, 49e) having different at least one of an opening size, an opening shape, and a depth.

Description

Technical Field

[0001] The invention relates to a semiconductor module. Background Art

[0002] The semiconductor module has a substrate on which semiconductor elements such as IGBT (Insulated Gate Bipolar Transistor), power MOSFET (Metal Oxide Semiconductor Field Effect Transistor), and FWD (Free Wheeling Diode) are provided, and is used in inverter devices and the like.

[0003] In such semiconductor modules, for example, in Patent Documents 1 to 3, a semiconductor element is arranged on an insulating substrate (also referred to as a laminated substrate), and a metal wiring plate (also referred to as a lead frame) for wiring is arranged on the upper surface electrode of the semiconductor element. The metal wiring plate is formed into a predetermined shape by, for example, stamping a metal plate. One end of the metal wiring plate is electrically bonded to the upper surface electrode via a bonding material such as solder.

[0004] In a semiconductor module, a sealing resin is filled inside a housing member, and an internal structure including a metal wiring board is covered with the sealing resin. In order to improve the adhesion strength of the sealing resin to the metal wiring board, in Patent Document 4, an ant nest-shaped groove whose opening is narrower than the width of the bottom is formed in the metal wiring board, and in Patent Document 5, a plurality of grid-shaped grooves are formed in the metal wiring board.

[0005] Patent Documents 6 to 9 describe forming a plurality of shallow pits on the surface of a metal wiring board and providing protrusions (returning portions, folded portions, hook-shaped portions) on the inner walls of the shallow pits to improve the sealing strength of the sealing resin. As a method of forming such shallow pits, a hole is formed by a first punching process, and a second punching process is performed on the periphery of the hole to deform the hole locally, so that a protrusion protrudes from the inner wall.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2018-088448

[0009] Patent Document 2: Japanese Patent Application Publication No. 2016-139635

[0010] Patent Document 3: Japanese Patent Application Publication No. 2015-176871

[0011] Patent Document 4: Japanese Patent Application Laid-Open No. 6-163773

[0012] Patent Document 5: Japanese Patent Application Publication No. 2021-077718

[0013] Patent Document 6: Japanese Patent Application Laid-Open No. 7-273270

[0014] Patent Document 7: Japanese Patent Application Publication No. 2005-191178

[0015] Patent Document 8: Japanese Patent Application Publication No. 2017-005124

[0016] Patent Document 9: Japanese Patent Application Publication No. 2007-258587 Summary of the invention

[0017] Problem that the invention aims to solve

[0018] In addition, in such semiconductor modules, the power semiconductor element generates heat due to switching operation. In the structure in which the metal wiring plate is soldered to the surface of the power semiconductor element as described above, deformation may occur at the joint portion due to the change of internal stress caused by temperature change. As a result, it is conceivable that the adhesion of the sealing resin to the joint portion of the metal wiring plate is reduced.

[0019] The present invention has been made in view of the above-mentioned situation, and one object of the present invention is to provide a semiconductor module capable of improving the adhesion between a joint portion of a metal wiring plate and a sealing resin.

[0020] Solutions for solving problems

[0021] A semiconductor module according to one technical solution of the present invention comprises: a stacked substrate having a plurality of circuit boards arranged on the upper surface of an insulating plate; a semiconductor element arranged on the upper surface of at least one of the circuit boards; and a metal wiring plate arranged on the upper surface of the semiconductor element, the metal wiring plate having a joining portion which is joined to the upper surface of the semiconductor element via a joining material, the joining portion comprising a plate-like portion having an upper surface and a lower surface, the plate-like portion having a plurality of roughened recesses which roughen the upper surface, the plurality of roughened recesses comprising a plurality of roughened recesses having at least one of different opening sizes, opening shapes, and depths.

[0022] Effects of the Invention

[0023] According to the present invention, it is possible to improve the adhesion between the joint portion of the metal wiring plate and the sealing resin in the semiconductor module. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the semiconductor device according to this embodiment as viewed from above.

[0025] Figure 2 Yes Figure 1 The semiconductor device shown is a cross-sectional view taken along line AA.

[0026] Figure 3 This is an enlarged view of the metal wiring plate of this embodiment.

[0027] Figure 4 Observe from the direction of arrow B Figure 3 The metal wiring plate shown is a plan view showing the first embodiment.

[0028] Figure 5 yes Figure 3 An enlarged view of portion C of the metal wiring board is shown.

[0029] Figure 6 It is a plan view showing a specific example of a semiconductor module to which the metal wiring plate according to the present embodiment is applied.

[0030] Figure 7 This is an equivalent circuit diagram of the semiconductor device according to this embodiment.

[0031] Figure 8 Observe from the direction of arrow B Figure 3 The metal wiring plate shown is a plan view showing a second embodiment.

[0032] Fig. 9 It is along Figure 8 A cross-sectional view taken along the DD line. DETAILED DESCRIPTION

[0033] The following describes a semiconductor module and a semiconductor device to which the present invention can be applied. Figures 1 to 7 The schematic structures of the entire semiconductor module and semiconductor device and the metal wiring plate included in the semiconductor module and the semiconductor device are described. Figure 1 This is a schematic diagram of the semiconductor device according to this embodiment as viewed from above. Figure 2 Yes Figure 1 The semiconductor device shown is a cross-sectional view taken along line AA. Figure 3 This is an enlarged view of the metal wiring plate of this embodiment. Figure 4 Observe from the direction of arrow B Figure 3 A top view of the metal wiring plate is shown. Figure 5 yes Figure 3 An enlarged view of portion C of the metal wiring board is shown. Figure 6 It is a plan view showing a specific example of a semiconductor module to which the metal wiring plate according to the present embodiment is applied. Figure 7: is an equivalent circuit diagram of the semiconductor device of the present embodiment. Here, as the semiconductor element 3, a structure in which an IGBT and an anti-parallel circuit of a FWD are connected in series is used.

[0034] In addition, in the following drawings, the length direction of the semiconductor module (cooler) is defined as the X direction, the width direction of the semiconductor module (cooler) is defined as the Y direction, and the height direction (thickness direction of the substrate) is defined as the Z direction. In addition, the length direction of the semiconductor module represents the direction in which multiple circuit boards are arranged. The X, Y, and Z axes shown in the figure are orthogonal to each other and constitute a right-hand system. In addition, depending on the situation, the X direction is sometimes referred to as the left-right direction, the Y direction is referred to as the front-back direction, and the Z direction is referred to as the up-down direction. These directions (front-back, left-right, up-down, and down-down directions) are terms used for the convenience of explanation, and sometimes the corresponding relationship with the XYZ directions will change depending on the installation posture of the semiconductor module. For example, the heat dissipation surface side (cooler side) of the semiconductor module is referred to as the lower surface side, and the opposite side is referred to as the upper surface side. In addition, in this specification, a top view refers to the situation of observing the upper or lower surface of the semiconductor module from the Z direction. In addition, the aspect ratios and the size relationships of the components in the figures are only represented by schematic diagrams, and therefore may not be consistent. For the convenience of explanation, it is also envisioned that there are situations in which the size relationships of the components are exaggerated.

[0035] The semiconductor device 100 of this embodiment is applied to a power conversion device such as an inverter for an industrial or vehicle-mounted motor. Figure 1 and Figure 2 As shown in FIG. 1 , the semiconductor device 100 is configured by placing the semiconductor module 1 on the upper surface of the cooler 10. The cooler 10 may have any structure with respect to the semiconductor module 1. FIG.

[0036] The cooler 10 is used to release the heat of the semiconductor module 1 to the outside, and has a rectangular parallelepiped shape as a whole. Although not specifically shown in the figure, the cooler 10 is provided with a plurality of heat sinks on the lower surface side of the base plate, and these heat sinks are housed in a water cooling jacket. In addition, the cooler 10 is not limited to this and can be appropriately changed.

[0037] Semiconductor module 1 is configured by arranging multilayer substrate 2 , semiconductor element 3 , metal wiring plate 4 and the like in casing 11 .

[0038] The laminated substrate 2 is composed of, for example, a DCB (Direct Copper Bonding) substrate, an AMB (Active Metal Brazing) substrate, or a metal base substrate. The laminated substrate 2 is formed by laminating an insulating plate 20, a heat sink 21, and a plurality of circuit boards 22, and is formed in a rectangular shape in plan view as a whole.

[0039] Specifically, the insulating plate 20 is formed of a plate-like body having an upper surface and a lower surface, and has a rectangular shape in a plan view that is long in the X direction. The insulating plate 20 can be formed of a ceramic material such as aluminum oxide (Al2O3), aluminum nitride (AlN), silicon nitride (Si3N4), aluminum oxide (Al2O3), and zirconium oxide (ZrO2).

[0040] In addition, the insulating plate 20 can be formed of, for example, a thermosetting resin such as epoxy resin or polyimide resin, or a composite material in which glass or ceramic material is used as a filler in the thermosetting resin. The insulating plate 20 is preferably flexible and can be formed of, for example, a material containing a thermosetting resin. In addition, the insulating plate 20 can also be called an insulating layer or an insulating film.

[0041] The heat sink 21 has a predetermined thickness in the Z direction and has a rectangular shape in a top view that is longer in the Y direction. The heat sink 21 is formed of a metal plate with good thermal conductivity, such as copper or aluminum. The heat sink 21 is arranged on the lower surface of the insulating plate 20. The lower surface of the heat sink 21 is a mounting surface relative to the cooler 10, which is the mounting object of the semiconductor module 1, and also functions as a heat dissipation surface (heat dissipation area) for releasing the heat of the semiconductor module 1. The heat sink 21 is joined to the upper surface of the cooler 10 via a joining material S1 such as solder. The heat sink 21 can also be arranged on the upper surface of the cooler 10 via a thermally conductive material such as thermal grease or a thermally conductive compound.

[0042] The plurality of circuit boards 22 each have a predetermined thickness and are arranged on the upper surface of the insulating plate 20. Each circuit board 22 is formed into an electrically independent island. For example, the circuit boards 22 have a rectangular shape in plan view and are arranged on the insulating plate 20 in a row along the X direction. Figure 1 As shown, the number is limited to two, but can be changed appropriately. Figure 6 As shown, more than three circuit boards 22 may be arranged on the insulating plate 20. In addition, the shape and arrangement position of the circuit board 22 are not limited thereto and can be appropriately changed. These circuit boards 22 are formed of metal plates with good thermal conductivity such as copper and aluminum. The circuit board 22 may also be called a circuit layer or a circuit pattern.

[0043] A semiconductor element 3 is arranged on the upper surface of a predetermined circuit board 22 (circuit board 22 on the negative side in the X direction) via a bonding material S2 such as solder. The semiconductor element 3 is formed into a rectangular shape in a plan view by a semiconductor substrate such as silicon (Si) or silicon carbide (SiC). The semiconductor element 3 may be a power semiconductor element. The semiconductor element 3 uses switching elements such as IGBT (Insulated Gate Bipolar Transistor), power MOSFET (Metal Oxide Semiconductor Field Effect Transistor), and diodes such as FWD (Free Wheeling Diode).

[0044] In the present embodiment, the semiconductor element 3 is formed of an RC (Reverse Conducting)-IGBT element in which the functions of an IGBT (Insulated Gate Bipolar Transistor) element and a FWD (Free Wheeling Diode) element are integrated.

[0045] In addition, the semiconductor element 3 is not limited thereto, and may also be composed of the above-mentioned switch elements, diodes, etc. For example, the IGBT element and the FWD element may also be separately constructed. In addition, as the semiconductor element 3, a RB (Reverse Blocking: reverse blocking)-IGBT or the like having sufficient withstand voltage against the reverse bias may also be used. In addition, the shape, number of configurations, configuration location, etc. of the semiconductor element 3 may be appropriately changed.

[0046] In addition, the semiconductor element 3 has electrodes (not shown) formed on the upper surface and the lower surface, respectively. For example, the electrode on the upper surface side (upper surface electrode) is composed of an emitter electrode (source electrode) or a gate electrode, and the electrode on the lower surface side (lower surface electrode) is composed of a collector electrode (drain electrode).

[0047] Furthermore, the semiconductor element 3 of the present embodiment is a so-called vertical switching element in which the above-mentioned functional element is formed on a semiconductor substrate, but the present invention is not limited thereto and may be a horizontal switching element.

[0048] A metal wiring plate 4 is disposed on the upper surface of the semiconductor element 3. The metal wiring plate 4 is composed of a plate-like body having an upper surface and a lower surface, and is formed of a metal material such as a copper material, a copper alloy material, an aluminum alloy material, an iron alloy material, etc. The metal wiring plate 4 is formed into a predetermined shape by, for example, stamping. In addition, the shape of the metal wiring plate 4 shown below is only an example, and can be appropriately changed. In addition, the metal wiring plate can also be called a lead frame.

[0049] The metal wiring plate 4 of this embodiment is a long strip extending in the X direction so as to span across a plurality of circuit boards 22 when viewed from above, and has a crank shape formed by bending multiple times when viewed from the side. Figure 2 and Figure 3 As shown, the metal wiring plate 4 is constructed to include: a first joining portion 40, which is joined to the upper surface (upper surface electrode) of the semiconductor element 3 via a joining material S3; a second joining portion 41, which is joined to the upper surface of the circuit board 22 on the positive side of the X direction via a joining material S4; and a connecting portion 42, which connects the first joining portion 40 and the second joining portion 41.

[0050] The width of the metal wiring plate 4 in the Y direction is the same from the first joint portion 40 to the second joint portion 41. In addition, the first joint portion 40, the second joint portion 41 and the connecting portion 42 are arranged in a row along the X direction when viewed from above. In addition, the width of the metal wiring plate 4 in the Y direction does not necessarily have to be the same from the first joint portion 40 to the second joint portion 41. Figure 6 As shown, they may also have different widths. In addition, the first joining portion 40, the second joining portion 41 and the connecting portion 42 are not necessarily arranged in a row. Figure 6 As shown, they may be arranged in an obliquely offset manner.

[0051] The first bonding portion 40 is formed in a rectangular shape smaller than the outer shape of the semiconductor element 3 in a plan view, and includes a plate-like portion having an upper surface and a lower surface. A first bent portion 43 is formed at the end of the first bonding portion 40 on the positive side in the X direction (on the connecting portion 42 side), and the first bent portion 43 is bent at a substantially right angle and stands upward. One end (left end) of the connecting portion 42 is connected to the upper end of the first bent portion 43.

[0052] A plurality of through holes 46 are formed in the first joining portion 40. A total of four through holes 46 are provided, two in each X direction and two in each Y direction. The four through holes 46 are arranged slightly inside the four corners of the first joining portion 40. Each through hole 46 penetrates the first joining portion 40 in the Z direction.

[0053] The second joint portion 41 is formed in a rectangular shape smaller than the outer shape of the circuit board 22 in a plan view, and includes a plate-like portion having an upper surface and a lower surface. A second bent portion 44 is formed at the end of the second joint portion 41 on the negative side in the X direction (the connecting portion 42 side), and the second bent portion 44 is bent at a substantially right angle and stands upward. The other end (right end) of the connecting portion 42 is connected to the upper end of the second bent portion 44.

[0054] A plurality of through holes 48 are formed in the second bonding portion 41. Two through holes 48 are provided at different positions in the Y direction. Each through hole 48 penetrates the second bonding portion 41 in the Z direction.

[0055] The connecting portion 42 extends in the horizontal direction, and as described above, one end is connected to the first curved portion 43 , and the other end is connected to the second curved portion 44 .

[0056] The length of the first bent portion 43 in the Z direction is shorter than the length of the second bent portion 44 in the Z direction by an amount corresponding to the thickness of the semiconductor element 3. That is, the first bonding portion 40 and the second bonding portion 41 are provided at positions of different heights. More specifically, the first bonding portion 40 is provided at a position higher than the second bonding portion 41.

[0057] In addition, the shape, number, and arrangement position of the metal wiring plate 4 are merely examples and are not limited thereto, and can be appropriately changed. Figure 6 As shown, a plurality of (e.g., four) metal wiring plates 4 may be provided for one semiconductor module, and the details are described later. In addition, in the present embodiment, the semiconductor element 3, the metal wiring plate 4, and the main terminals described later form a semiconductor module. Figure 7 The inverter circuit is shown.

[0058] The stacked substrate 2, the semiconductor element 3 and the metal wiring plate 4 are surrounded by a shell 11. The shell 11 has a cylindrical shape or a frame shape that is a square ring when viewed from above, and is formed of, for example, a synthetic resin. The shell 11 can also be formed of a thermosetting resin material such as epoxy resin, silicone rubber, etc. The lower end of the shell 11 is bonded to the upper surface of the cooler 10 via an adhesive (not shown), and the upper end extends to a position that is sufficiently higher than the upper surface of the metal wiring plate 4. Thus, the shell 11 surrounds the stacked substrate 2, the semiconductor element 3 and the metal wiring plate 4, and defines a space for storing the stacked substrate 2, the semiconductor element 3 and the metal wiring plate 4.

[0059] The internal space defined by case 11 is filled with sealing resin 5. Sealing resin 5 may be filled to the upper surface and reach the upper end of case 11. Thus, laminated substrate 2, semiconductor element 3 and metal wiring plate 4 are sealed. Metal wiring plate 4 is entirely covered with sealing resin 5.

[0060] The sealing resin 5 may be made of, for example, a thermosetting resin. The sealing resin 5 preferably contains at least one of epoxy, silicone, polyurethane, polyimide, polyamide, and polyamide-imide. From the viewpoint of insulation, heat resistance, and heat dissipation, the sealing resin 5 is preferably, for example, an epoxy resin mixed with a filler.

[0061] In addition, if Figure 6 As shown in the specific example, a plurality of main terminals 60 for main current and a plurality of control terminals 61 for control may be provided in the housing 11. The main terminals 60 are formed of a plate-like elongated body and embedded in the side wall of the housing 11. Figure 6In the embodiment, two main terminals 60 constituting an N terminal and a P terminal are arranged in the X direction on the side wall of the housing 11 located on the negative side in the Y direction. In addition, a main terminal 60 constituting an M terminal is arranged on the side wall of the housing 11 located on the positive side in the Y direction.

[0062] As described above, in this embodiment, semiconductor element 3, metal wiring plate 4, main terminal 60, etc. form a Figure 7 The inverter circuit shown in FIG. These main terminals 60 (N terminal, P terminal, M terminal) each correspond to Figure 7 IN(N) (also called low potential side input terminal or negative terminal), IN(P) (also called high potential side input terminal or positive terminal), OUT(M) (also called output terminal or intermediate terminal).

[0063] In addition, the control terminal 61 is formed of a plate-like long strip and embedded in the side wall of the housing 11 located on the positive side in the Y direction. The control terminal 61 is electrically connected to a predetermined control electrode of the semiconductor element 3 via a wiring member such as a bonding wire. These main terminals 60 and control terminals 61 are formed of metal materials such as copper materials, copper alloy materials, aluminum alloy materials, and iron alloy materials, and have a predetermined electrical conductivity and a predetermined mechanical strength. The shape, number, and arrangement position of the main terminals 60 and control terminals 61 are not limited to these, and can be appropriately changed.

[0064] In addition, in the semiconductor module, it is sought to prevent peeling from progressing along the interface between the metal wiring board and the sealing resin. As a method of reducing peeling, for example, it is considered to increase the surface area of ​​the metal wiring board to improve the closeness between the metal wiring board and the sealing resin (anchor effect). As a method of increasing the surface area of ​​the metal wiring board, it can be cited that a concave-convex shape is formed on the surface of the metal wiring board. However, if the lower surface of the metal wiring board (the surface opposite to the semiconductor element) has a concave-convex shape, it will be easy for the bonding material to produce gaps and shrinkage. As a result, the installation quality of the metal wiring board may be affected.

[0065] In addition, as methods for roughening the surface of the metal wiring plate, laser processing, wet methods based on chemical solutions, etc. can be cited. However, these methods will not only become the main cause of cost increase, but also the lower surface side of the metal wiring plate will be roughened, which will easily cause gaps and shrinkage in the bonding material. In other words, it is difficult to roughen the surface of the metal wiring plate without affecting the quality of the bonding material directly below the metal wiring plate.

[0066] In the present embodiment, a plurality of through holes 46 are provided in the first bonding portion 40, and a plurality of roughened recessed portions 49 are provided on the upper surface (outer surface) of the first bonding portion 40. By forming a plurality of through holes 46, the thickness of the bonding material S3 can be ensured in the bonding process of the metal wiring plate 4, and the first bonding portion 40 is prevented from being tilted relative to the upper surface of the semiconductor element 3, so that the posture of the metal wiring plate 4 (first bonding portion 40) is stabilized.

[0067] Through hole 48 formed in second bonding portion 41 has the same effect as through hole 46 of first bonding portion 40. Therefore, in the bonding process of metal wiring plate 4, the thickness of bonding material S4 can be ensured, and second bonding portion 41 can be prevented from tilting relative to the upper surface of circuit board 22, so that the posture of metal wiring plate 4 (second bonding portion 41) is stabilized.

[0068] The through hole 46 and the through hole 48 are cylindrical. In addition, the shape of the through hole formed in the first bonding part 40 and the second bonding part 41 is not limited to the cylindrical shape.

[0069] In addition, a plurality of roughened recesses 49 are formed on the upper surface of the first joint portion 40, thereby roughening the surface. As a result, the surface area of ​​the upper surface of the first joint portion 40 increases, and the adhesion (anchoring effect) between the upper surface of the first joint portion 40 and the sealing resin 5 can be improved. In particular, it is preferred that the sealing resin 5 enters the roughened recesses 49. Thus, a further anchoring effect can be expected. Therefore, above the semiconductor element 3, the peeling progress of the sealing resin 5 at the upper surface of the metal wiring plate 4 caused by thermal stress can be suppressed.

[0070] The through hole 46 and the roughened recessed portion 49 in the first joining portion 40 and the through hole 48 in the second joining portion 41 are formed by, for example, press working.

[0071] In addition, the plurality of roughened recessed portions 49 may be formed on the upper surface of the second joining portion 41, or may be formed only on the upper surface of the first joining portion 40. That is, the roughened recessed portions 49 may not be formed on the connecting portion 42, the first curved portion 43, and the second curved portion 44 that constitute the portion other than the first joining portion 40.

[0072] Since the semiconductor element 3 as a heat source is arranged directly below the first joint portion 40, it can be easily affected by the anchoring effect of the surface roughening. In addition, by roughening only the surface of the portion where the anchoring effect should be improved, there is no need to spend extra processing costs. That is, it can be said that the second joint portion 41, the connecting portion 42, the first bent portion 43 and the second bent portion 44 have less effect on the peeling of the sealing resin 5 than the first joint portion 40. In this case, the surfaces of the second joint portion 41, the connecting portion 42, the first bent portion 43 and the second bent portion 44 are flat, and their surface roughness can be equal to the surface roughness of the lower surface of the first joint portion 40.

[0073] In addition, the lower surface of the first bonding portion 40 is preferably a flat surface except for the through hole 46. That is, it is preferred that the roughened recessed portion 49 is not formed on the lower surface of the first bonding portion 40. For example, the surface roughness of the lower surface of the first bonding portion 40 is preferably smaller than the surface roughness of the upper surface of the first bonding portion 40. By making the lower surface of the first bonding portion 40 flat, it is not easy to generate gaps and shrinkage in the bonding material S3.

[0074] In addition, if Figure 5 As shown, a coating film F may be interposed at the interface between the upper surface of the first bonding portion 40 and the sealing resin 5 .

[0075] Next, the main reference Figure 4 , Figure 8 as well as Fig. 9 An embodiment showing the structure of a plurality of roughened recessed portions ( 49 ) provided on the upper surface of the first joining portion 40 will be described. Figure 4 This is the first embodiment. Figure 8 and Fig. 9 This is the second embodiment. In each embodiment, the upper surface of the first bonding portion 40 has a roughened area whose surface is roughened by using a plurality of roughened recesses and a non-roughened area where no roughened recesses are formed. The non-roughened area includes four through holes 46. Moreover, the roughened area is composed of a plurality of roughened recesses having at least one different opening size, opening shape, and depth.

[0076] Figure 4The first embodiment shown is provided with two kinds of roughened recesses of different sizes on the upper surface of the first joining portion 40. That is, the upper surface of the first joining portion 40 is provided with a first roughened recess 49a and a second roughened recess 49b having an opening size smaller than the opening size of the first roughened recess 49a. The size of the roughened recess here refers in particular to the opening size when viewed from above. The first roughened recess 49a and the second roughened recess 49b are both recesses in the shape of a quadrangular prism (rectangular shape when viewed from above). The opening sizes of the first roughened recess 49a and the second roughened recess 49b are different, and the opening size of the second roughened recess 49b is smaller than the opening size of the first roughened recess 49a.

[0077] A plurality of the first roughened recessed portions 49a and the second roughened recessed portions 49b are provided on the upper surface of the first bonding portion 40. The interval (pitch) of the second roughened recessed portions 49b in the X direction and the Y direction at the portion where the plurality of second roughened recessed portions 49b are arranged is smaller than the interval (pitch) of the first roughened recessed portions 49a. In other words, the first roughened recessed portions 49a and the second roughened recessed portions 49b having different opening sizes are arranged at different intervals.

[0078] On the upper surface of the first joint portion 40, a first roughening recess 49a having a larger opening size is arranged in an area where sufficient space can be ensured. On this basis, a second roughening recess 49b having a smaller opening size is arranged in an area where the first roughening recess 49a is not suitable for arrangement due to space limitations. Specifically, the second roughening recess 49b is arranged around the four through holes 46 included in the non-roughening area and near the four corners of the rectangular-shaped first joint portion 40. In the area adjacent to the non-roughening area (through holes 46), the anchoring effect can be improved by arranging small second roughening recesses 49b at a high density. In addition, peeling at the interface between the first joint portion 40 and the sealing resin 5 is easy to occur from the outer peripheral portion (end) of the first joint portion 40, but by arranging small second roughening recesses 49b at the four corners of the first joint portion 40, surface roughening can be achieved in the area where peeling is most likely to occur.

[0079] By disposing two types of first roughened recessed portions 49a and second roughened recessed portions 49b of different sizes in a mixed manner, the surface can be roughened with better space utilization and the surface area of ​​the first bonding portion 40 can be increased compared to the case where only one type of roughened recessed portion is used. In particular, in portions where space is more restricted, such as the periphery of the through hole 46 and positions near the four corners of the first bonding portion 40, the small second roughened recessed portions 49b can be used to improve the surface roughening effect.

[0080] In addition, the shapes of the first roughened concave portion 49a and the second roughened concave portion 49b may be shapes other than quadrangular prisms, for example, they may be prisms other than quadrangular prisms (hexagonal prisms, etc.), cylinders, spherical shapes, etc. In addition, the depths of the first roughened concave portion 49a and the second roughened concave portion 49b may be the same or different. Moreover, it is not limited to the first roughened concave portion 49a and the second roughened concave portion 49b, and three or more roughened concave portions of different sizes (opening sizes) may be mixed and configured.

[0081] Figure 8 and Fig. 9 The second embodiment shown in the figure is provided with three kinds of roughened recesses of different shapes, namely, the third roughened recesses 49c, the fourth roughened recesses 49d and the fifth roughened recesses 49e, respectively, on the upper surface of the first bonding portion 40. The third roughened recesses 49c are arranged at predetermined intervals in the X direction and the Y direction, and the fourth roughened recesses 49d and the fifth roughened recesses 49e, which are different in shape from the third roughened recesses 49c, are arranged locally. Specifically, the fourth roughened recesses 49d are arranged around the four through holes 46D included in the non-roughened area, and the fifth roughened recesses 49e are arranged near the four corners of the first bonding portion 40.

[0082] The third roughened recessed portion 49c is Figure 4 The fourth roughened concave portion 49d is a concave portion with a rectangular opening shape with the length direction facing the X direction. The fifth roughened concave portion 49e is a concave portion with an L-shaped opening shape with the length direction facing the Y direction and one end in the Y direction bent in the X direction.

[0083] In the Y direction, three fourth roughened recesses 49d are arranged between two through holes 46. The interval (pitch) of the three fourth roughened recesses 49d in the Y direction is smaller than the interval (pitch) of the third roughened recesses 49c in the X direction and the Y direction. That is, the third roughened recesses 49c and the fourth roughened recesses 49d are arranged at different intervals, respectively, and in the area adjacent to the non-roughened area (through hole 46), the fourth roughened recesses 49d are arranged at a high density with the intervals reduced to improve the anchoring effect.

[0084] In addition, in the Y direction, a fourth roughened recessed portion 49d is disposed on the outer side of each through hole 46. Therefore, the fourth roughened recessed portion 49d is disposed on both sides of each through hole 46 in the Y direction, and the surface area of ​​the upper surface of the first bonding portion 40 can be efficiently increased relative to both sides of the inner side and the outer side of the through hole 46 in the Y direction, thereby obtaining an excellent anchoring effect.

[0085] The fifth roughened recessed portion 49e has an L-shaped opening along the four corners of the first bonding portion 40. This can effectively increase the surface area of ​​the upper surface of the first bonding portion 40 near the four corners, thereby obtaining an excellent anchoring effect.

[0086] By disposing three kinds of roughened recessed portions having different shapes, namely, the third roughened recessed portion 49c, the fourth roughened recessed portion 49d, and the fifth roughened recessed portion 49e in a mixed manner, it is possible to perform surface roughening with better space utilization and increase the surface area of ​​the first bonding portion 40 compared to the case where only one kind of roughened recessed portion is used. In particular, the surface roughening effect can be improved in portions where space is more restricted, such as the periphery of the through hole 46 and positions near the four corners of the first bonding portion 40.

[0087] Fig. 9 Indicates along Figure 8 The cross-sectional structure of the first joint portion 40 at the position of the DD line. Fig. 9 As shown, the third roughened recessed portion 49c, the fourth roughened recessed portion 49d, and the fifth roughened recessed portion 49e have different depths. The depth Z2 of the fourth roughened recessed portion 49d is smaller than the depth Z1 of the third roughened recessed portion 49c, and the depth Z3 of the fifth roughened recessed portion 49e is larger than the depth Z1 of the third roughened recessed portion 49c.

[0088] By making the depths of the third roughened recessed portion 49c, the fourth roughened recessed portion 49d, and the fifth roughened recessed portion 49e different in this way, a difference in the surface area of ​​the first bonding portion 40 corresponding to the depth is generated. Therefore, by appropriately managing the depths of the third roughened recessed portion 49c, the fourth roughened recessed portion 49d, and the fifth roughened recessed portion 49e, the surface roughening effect of the first bonding portion 40 can be further improved.

[0089] As described above, the peeling at the interface between the first bonding portion 40 and the sealing resin 5 is likely to occur from the outer peripheral portion (end portion) of the first bonding portion 40, and the peeling occurring at the outer peripheral portion of the first bonding portion 40 advances toward the inner region of the first bonding portion 40. By increasing the depth of the fifth roughened recessed portion 49e disposed near the four corners of the first bonding portion 40, the anchoring effect can be enhanced, and the peeling of the sealing resin 5 at the outer peripheral portion of the first bonding portion 40 can be suppressed.

[0090] As described above, the third roughened recessed portion 49c, the fourth roughened recessed portion 49d, and the fifth roughened recessed portion 49e have different opening shapes in plan view and depths in the Z direction. That is, the elements defining the shape of the roughened recessed portion include at least the opening shape and the depth.

[0091] In addition, Fig. 9In the structure, the three types of roughened concave portions, namely the third roughened concave portion 49c, the fourth roughened concave portion 49d and the fifth roughened concave portion 49e, which have different opening shapes, are mixedly arranged, but two types of roughened concave portions having different opening shapes and depths or four or more types of roughened concave portions having different opening shapes and depths may be mixedly arranged. In addition, the difference between the third roughened concave portion 49c, the fourth roughened concave portion 49d and the fifth roughened concave portion 49e may be only the opening shape, and the depths may be made the same.

[0092] In summary, the first and second embodiments described above are provided with a plurality of roughened recessed portions having at least one of different opening size, opening shape, and depth on the upper surface of the first bonding portion 40. Thus, it is easy to arrange the plurality of roughened recessed portions at a higher density, thereby increasing the degree of increase in surface area achieved by the plurality of roughened recessed portions.

[0093] Furthermore, the plurality of types of roughened recessed portions are arranged at different intervals suitable for their respective opening sizes and opening shapes, and the roughened recessed portions can be arranged at a high density with good space utilization.

[0094] In addition, the second roughened recessed portion 49b and the fourth roughened recessed portion 49d arranged around the through hole 46 included in the non-roughened area on the upper surface of the first bonding portion 40 have different opening sizes or opening shapes from the first roughened recessed portion 49a and the third roughened recessed portion 49c arranged at a position away from the through hole 46. Thus, the roughened recessed portion can be spread to the vicinity of the through hole 46 having a circular shape in plan view, thereby improving the surface roughening effect.

[0095] In addition, in the above-mentioned embodiment, the first joint portion 40 of the metal wiring plate 4 has a through hole 46 in the non-roughened area on the upper surface, but the structure of the non-roughened area is not limited to the through hole. For example, in the case where a wire is connected to the upper surface of the metal wiring plate 4, the portion where the wire is connected may also be the non-roughened area. In addition, a protrusion protruding upward from the metal wiring plate 4, a bottomed hole (a concave portion having a shape, depth, etc. different from the roughened concave portion) provided on the upper surface of the metal wiring plate 4, etc. may also be applied as the non-roughened area.

[0096] Furthermore, the present invention can also be applied to a joint portion of a metal wiring plate having no non-roughened region such as through-hole 46 on the upper surface (a plurality of roughened recessed portions are arranged as a whole).

[0097] In addition, the shapes of the various roughened recesses are not limited to Figure 4 , Figure 8 as well as Fig. 9 For example, a roughened recessed portion having a triangular, circular, elliptical, or other shape when viewed from above can also be applied.

[0098] As described above, according to this embodiment, the adhesion between the metal wiring plate and the sealing resin can be improved. In addition, the bonding strength between the semiconductor element and the metal wiring plate can be improved while ensuring the thickness of the bonding material.

[0099] Although the present embodiment and the modified examples have been described, the above-described embodiment and the modified examples may be combined in whole or in part as other embodiments.

[0100] In addition, in the above-mentioned embodiment, the number and arrangement positions of the semiconductor elements are not limited to the above-mentioned configurations, and can be changed as appropriate.

[0101] In addition, in the above-mentioned embodiment, the number and layout of the circuit boards are not limited to the above-mentioned configuration, but can be changed as appropriate.

[0102] In the above-described embodiments, the laminate substrate and the semiconductor element are configured to be rectangular or square in plan view, but the present invention is not limited to this configuration and these structures may be configured to be polygonal shapes other than those described above.

[0103] In addition, the present embodiment is not limited to the above-mentioned embodiment and variation, and various changes, substitutions, and variations can be made within the scope of the main purpose of the technical idea. In addition, if the technical idea can be realized in other ways due to technological progress or other derived technologies, the method can also be used for implementation. Therefore, the claims cover all embodiments that can be included in the scope of the technical idea.

[0104] The characteristic points of the above-mentioned embodiment are summarized below.

[0105] The semiconductor module of the above-mentioned embodiment comprises: a stacked substrate, which has a plurality of circuit boards arranged on the upper surface of an insulating plate; a semiconductor element, which is arranged on the upper surface of at least one of the circuit boards; and a metal wiring plate, which is arranged on the upper surface of the semiconductor element, the metal wiring plate having a joining portion, which is joined to the upper surface of the semiconductor element via a joining material, the joining portion including a plate-like portion, the plate-like portion having an upper surface and a lower surface, the plate-like portion having a plurality of roughened recesses, the plurality of roughened recesses roughening the upper surface, the plurality of roughened recesses including a plurality of roughened recesses having at least one of different opening sizes, opening shapes, and depths.

[0106] In addition, the plurality of types of roughened recessed portions are arranged at different intervals.

[0107] In addition, the upper surface of the plate-like portion has a non-roughened area, which does not have the roughened recessed portion, and the roughened recessed portion arranged around the non-roughened area has an opening size or an opening shape different from that of the roughened recessed portion arranged at a position away from the non-roughened area.

[0108] Furthermore, the non-roughened region has a through hole that penetrates the plate-like portion.

[0109] In addition, the bonding portion has a rectangular shape in a plan view, and has the roughened recessed portion having an L-shaped opening along a corner portion of the bonding portion.

[0110] Industrial Applicability

[0111] As described above, the present invention has an effect of improving the adhesion between the joint portion of the metal wiring plate and the sealing resin, and is particularly useful for semiconductor modules for industrial use or electrical equipment.

[0112] This application is based on Japanese Patent Application No. 2022-177077 filed on November 4, 2022, the contents of which are incorporated herein in their entirety.

[0113] Description of Reference Numerals

[0114] 1. semiconductor module; 2. laminated substrate; 3. semiconductor element; 4. metal wiring board; 5. sealing resin; 10. cooler; 11. housing; 20. insulating plate; 21. heat sink; 22. circuit board; 40. first joint (joint); 41. second joint; 42. connecting portion; 43. first bent portion; 44. second bent portion; 46. through hole (non-roughened area); 48. through hole; 49. roughened recess; 49a. first roughened portion Roughening recess; 49b, second roughening recess; 49c, third roughening recess; 49d, fourth roughening recess; 49e, fifth roughening recess; 60, main terminal; 61, control terminal; 100, semiconductor device; F, coating film; S1, bonding material; S2, bonding material; S3, bonding material; S4, bonding material; Z1, depth of the third roughening recess; Z2, depth of the fourth roughening recess; Z3, depth of the fifth roughening recess.

Claims

1. A semiconductor module, wherein: The semiconductor module has: A laminate substrate having a plurality of circuit boards arranged on an upper surface of an insulating plate; a semiconductor element disposed on an upper surface of at least one of the circuit boards; and a metal wiring plate disposed on the upper surface of the semiconductor element, The metal wiring plate has a bonding portion bonded to the upper surface of the semiconductor element via a bonding material. The engaging portion includes a plate-shaped portion having an upper surface and a lower surface, The plate-like portion has a plurality of roughened recessed portions, and the plurality of roughened recessed portions roughen the upper surface, The plurality of roughened recessed portions include a plurality of types of roughened recessed portions having different opening sizes, opening shapes, and depths.

2. The semiconductor module according to claim 1, wherein: The plurality of roughened recessed portions are arranged at different intervals.

3. The semiconductor module according to claim 1 or 2, wherein: The upper surface of the plate-shaped portion has a non-roughened area, the non-roughened area does not have the roughened recessed portion, The roughened recessed portions arranged at the periphery of the non-roughened region and the roughened recessed portions arranged at a position away from the non-roughened region have opening sizes or opening shapes that are different.

4. The semiconductor module according to claim 3, wherein: The non-roughened region has a through hole that penetrates the plate-shaped portion.

5. The semiconductor module according to claim 1 or 2, wherein: The joining portion has a rectangular shape in a plan view, and has the roughened recessed portion having an L-shaped opening along a corner portion of the joining portion.

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