Semiconductor Module

Abstract

To provide a semiconductor module capable of achieving both improved substrate cooling performance and higher density of a terminal part wiring.SOLUTION: A semiconductor module comprises: a circuit body including a semiconductor element and a plurality of external terminals connected to the semiconductor element; a substrate including a power wiring layer connected to the plurality of external terminals; an insulating filling member covering a connection part between the plurality of external terminals and the power wiring layer; a cooler in which the circuit body and the substrate are mounted on one surface side; and a heat dissipation member arranged between the cooler and the substrate. The heat dissipation member forms a frame part so as to surround an outer periphery of a region in which the circuit body is mounted on the cooler. An inner peripheral side of the frame part is filled with the filling member.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] As background art of the present invention, Patent Document 1 below discloses a power module substrate and a power module in which a heat dissipation member is disposed over the entire surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6481409 Summary of the Invention [Problem to be solved by the invention]

[0004] Considering the perspectives of improving substrate cooling performance for larger currents and individually packaging the power module portion for improved productivity, the technology of Patent Document 1 presents challenges in that simultaneous cooling is difficult due to the difference in height between the semiconductor module and the substrate, and furthermore, when using a sprayable insulating coating, the low viscosity makes it difficult to achieve a thick film (high voltage resistance), and it is also difficult to arrange a potting mold on the underside of the substrate to fill the insulating coating. Based on these challenges, the objective of the present invention is to provide a semiconductor module that achieves both improved substrate cooling performance and high-density terminal wiring. [Means for solving the problem]

[0005] The semiconductor module of the present invention comprises a circuit body having a semiconductor element and a plurality of external terminals connected to the semiconductor element, a substrate having a power wiring layer connected to the plurality of external terminals, an insulating filling member covering the connection portion between the plurality of external terminals and the power wiring layer, a cooler on one side of which the circuit body and the substrate are mounted, and a heat dissipation member arranged between the cooler and the substrate, wherein the heat dissipation member forms a frame portion on the cooler so as to surround the outer periphery of the area where the circuit body is mounted, and the filling member is filled on the inner periphery of the frame portion. [Effects of the Invention]

[0006] It is possible to provide a semiconductor module that achieves both improved cooling performance of the substrate and high-density wiring of the terminal portion. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is a top view of the entire substrate-integrated semiconductor module. [Figure 2] 2 is a cross-sectional view taken along the line AA' in FIG. [Figure 3] FIG. 2 is a cross-sectional view taken along the line BB′ of FIG. [Figure 4] This is a first modification of FIG. [Figure 5] This is the second example of Figure 3. [Figure 6] This is a third modification of FIG.

[0008] (One embodiment of the present invention and overall configuration) Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The following description and drawings are examples for explaining the present invention, and some omissions and simplifications have been made as appropriate for clarity of explanation. The present invention can be implemented in various other forms. Unless otherwise specified, each component may be singular or plural.

[0009] In order to facilitate understanding of the invention, the position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings.

[0010] (Figure 1) The substrate-integrated semiconductor module 100 is a circuit module that constitutes a power conversion circuit of a power conversion device. The semiconductor module 100 has a circuit body 1, a power wiring layer 3, a heat dissipation member 4, and a substrate 5. The substrate 5 is a resin-like printed circuit board (control circuit board). The heat dissipation member 4 is formed in a sheet shape on the substrate 5 and is arranged to surround each circuit body 1. The power wiring layer 3 is connected to the circuit body 1 via external terminals 2 that each circuit body 1 has.

[0011] The reason why the heat dissipation member 4 is in a sheet shape is that a large amount of heat dissipation member 4 is required corresponding to the amount of current in the main circuit section of the power conversion device. As will be explained in detail later, a frame portion 4a is formed around the circuit body 1 and the external terminals 2 of the circuit body 1 by the large amount of heat dissipation member 4, which makes it possible to prevent leakage of the filling material filled around the circuit body 1.

[0012] (Fig. 2, Fig. 3) The power wiring layers 3 are formed on the top and bottom surfaces of the substrate 5. The circuit body 1 is disposed on the inner periphery of a through hole 14 provided in the substrate 5. The circuit body 1 has its sides fixed to the substrate 5 via an insulating filler member 12, thereby improving vibration resistance. The circuit body 1 has a conductive member 9 and a semiconductor element 10, each of which is covered with a sealing resin 11. This insulates the semiconductor element 10 and the conductive member 9 from surrounding electrical components and protects them from foreign matter.

[0013] The semiconductor element 10 may be an IGBT (Insulated Gate Bipolar Transistor) element, a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) element, a diode element, etc. The semiconductor element 10 is electrically connected to the conductive member 9 via connection wiring such as a bonding wire or a joining material such as solder.

[0014] The conductive member 9 has external terminals 2 that connect the circuit body 1 to electrical components such as a substrate 5. The external terminals 2 are connected to the semiconductor element 10, and electrically connected to the power wiring layer 3 (lower side in the figure) of the substrate 5 by a bonding material such as solder. The substrate 5 is composed of the power wiring layer 3 and an insulating resin layer. The circuit body 1 is connected to other electrical components (not shown) via the external terminals 2 and the substrate 5, and forms a power conversion circuit.

[0015] Through holes 14 formed in substrate 5, filling material 12 is filled so as to cover the connection portions of circuit body 1 and external terminals 2 with power wiring layer 3. Filling material 12 is an insulating material such as resin, and by filling, insulation is provided between circuit body 1 and external terminals 2, and between power wiring layer 3 and cooler 7. The presence of through holes 14 makes it easy to check the filling condition of filling material 12 (presence or absence of bubbles, filling rate, etc.) from the top surface of substrate 5, thereby improving the reliability of the filling result of filling material 12.

[0016] A heat transfer member 13 is provided below the conductive member 9, and an insulating member 6 is provided further below that. The insulating member 6 is made of a ceramic substrate, an insulating resin sheet, or the like, and is fixed to the cooler 7 by brazing or crimping. The insulating member 6 is in contact with the heat dissipation member 4, the filler member 12, and the heat transfer member 13 at its upper side. The heat dissipation member 4 is in contact with the power wiring layer 3 on the lower side of the substrate 5. In other words, the heat dissipation member 4 is disposed between the substrate 5 and the cooler 7, and further, the power wiring layer 3 and the cooler 7 are in contact with each other via the heat dissipation member 4 and the insulating member 6. This allows the power wiring layer 3 to dissipate heat to the refrigerant 8 flowing inside the cooler 7, thereby reducing the temperature of the substrate 5.

[0017] Heat dissipation grease or the like that has high thermal conductivity and can also suppress contact thermal resistance is used for the heat transfer member 13. The heat dissipation member 4 is made of a resin sheet or the like that has high thermal conductivity and elasticity (stretchability) that can follow the steps and warpage of the substrate 5.

[0018] Furthermore, the insulating member 6 is disposed between the cooler 7 and the circuit body 1 and between the cooler 7 and the substrate 5, thereby providing insulation between the cooler 7 and the circuit body 1 and between the cooler 7 and the substrate 5. Furthermore, the heat dissipation member 4 is formed on the cooler 7, thereby enhancing the cooling effect of the circuit body 1 via the filler member 12 filled in the inner region (the region surrounded by the frame portion 4a).

[0019] The area surrounded by the heat dissipation member 4, which forms the frame portion 4a on the insulating member 6 on the bottom surface, is filled with the filling member 12 from the through holes 14 without leaving any gaps, as described above, so that the filling member 12 surrounds the outer periphery of the area where the circuit body 1 is mounted. This allows the filling member 12 to function as a potting mold for the circuit body 1, preventing the insulating coating material (filling member 12) from leaking out and reliably insulating the circuit body 1 from the substrate 5 and the power wiring layer 3. This allows a filling member 12 with a low viscosity to be used during filling, making the filling process easier than before. When a filling member with a low viscosity is used, air bubbles generated in the filling member 12 can be easily eliminated, and by suppressing the incorporation of air bubbles, the insulation reliability of the semiconductor module 100 can be improved.

[0020] The filling member 12 is filled on the inner periphery of the frame portion 4a formed by the sheet-like heat dissipation member 4. This reduces the required insulation distance between the external terminals 2 with different potentials that protrude from the same direction of the circuit body 1, making it possible to place the external terminals 2 closer to each other, thereby enabling the circuit body 1 and the entire substrate-integrated semiconductor module 100 to be miniaturized.

[0021] In this regard, the width between the two external terminals 2 protruding in the same direction from the circuit body 1 needs to be approximately 3 to 4 mm, for example, considering that the voltage is high and that the external terminals 2 carry signals of different voltages and require insulation. However, by filling the area surrounded by the heat dissipation member 4 with the filling member 12 without any gaps, as in the present invention, it becomes possible to maintain the insulating distance even if the width between the two terminals is further narrowed, which contributes to miniaturization.

[0022] The cooler 7 is disposed as a cooler for the circuit body 1 and the substrate 5, and cools the circuit body 1 and the substrate 5 via the heat transfer member 13, the heat dissipation member 4, or the insulating member 6. The cooler 7 is made of a material with excellent thermal conductivity, such as aluminum or copper. The cooler 7 is provided with fins or pins on the surface that comes into contact with the refrigerant 8, thereby increasing the surface area that comes into contact with the refrigerant 8 and improving the cooling performance of the cooler 7. The refrigerant 8 is a liquid, such as cooling water, which is pumped from the outside to the flow path of the cooler 7 by a pump (not shown), and flows through the internal flow path of the cooler 7.

[0023] The external terminals 2 and the power wiring layer 3 are arranged so that they are partially in contact with each other (Figure 3). The reason for this arrangement is that when creating an actual circuit, the width of the wiring layer 3 of the substrate 5 changes depending on the amount of current flowing, so the placement of the circuit body 1 may be separated in some places, and it is therefore necessary to improve the flexibility of the placement of the circuit body 1. Therefore, by making some of the power wiring layer 3 thinner and creating a step in some places, it is possible to consider measures to prevent component misalignment at the contact points with the external terminals 2 while leaving the layer of the external terminals 2 intact. Note that the circuit body 1 (external terminals 2) and the substrate 5 may be arranged vertically offset depending on the design convenience.

[0024] (First Modification) (Figure 4) The substrate 5 has through holes 14, and is shaped so that a portion of the substrate 5 covers the circuit body 1, thereby acting as a lid for the circuit body 1. The through holes 14 are also arranged on the inner periphery of the frame 4a formed by the heat dissipation member 4. This makes it easier to adjust the amount of filling material 12 to be filled, improving the reliability of applying an appropriate amount of filling material 12. Furthermore, providing multiple through holes 14 improves the filling speed and also makes it easier to remove air bubbles.

[0025] (Second Modification) (Figure 5) The fixing member 15 fastens the substrate 5 and the cooler 7 by passing through a fixing hole provided in the substrate 5 and a fixing hole provided in the cooler 7 for passing the fixing member 15 therethrough. Bolts, screws, or the like are used for the fixing member 15. The fixing member 15 is disposed on the inner periphery of the frame portion 4a formed by the heat dissipation member 4. By disposing the fixing member 15 near the heat dissipation member 4, it is possible to improve the adhesion between the substrate 5 and the heat dissipation member 4 and between the insulating member 6 and the heat dissipation member 4, and to prevent the filling member 12 from flowing out. Furthermore, the through hole 14 in the insulating member 6 created (formed) by the fixing member 15 is filled with the filling member 12, and the cooler 7 and the substrate 5, and the cooler 7 and the circuit body 1 are insulated from each other.

[0026] (Third Modification) (Figure 6) The cooler 7 is disposed on both the upper and lower surfaces of the circuit body 1, cooling both sides of the semiconductor element 10 of the circuit body 1. The cooler disposed on the upper surface is referred to as cooler 7a. The second insulating member 6a, which is in contact with the cooler 7a, is made of a ceramic substrate or an insulating resin sheet and is fixed to the second cooler 7a by brazing or crimping. The second insulating member 6a is disposed between the second cooler 7a and the circuit body 1, and between the second cooler 7a and the substrate 5, thereby insulating the second cooler 7a from the circuit body 1 and the second cooler 7a from the substrate 5, respectively. The second heat transfer member 13a is disposed between the circuit body 1 and the second insulating member 6a and is made of a thermal grease or the like that has high thermal conductivity and can reduce contact thermal resistance. The second cooler 7a is disposed in a position that does not overlap with the through-hole 14 of the substrate 5, which is filled with the filler 12.

[0027] This allows the circuit body 1 to be cooled from the top as well, further suppressing the temperature rise of the semiconductor elements inside the circuit body 1 and improving the reliability of the circuit body 1. Furthermore, it becomes possible to fill the circuit body 1 with the filler 12 in a state where the cooler 7 and the second cooler 7a are attached to the board 5 and the circuit body 1, and furthermore, it becomes possible to visually check the filling state of the filler 12.

[0028] According to the embodiment of the present invention described above, the following advantageous effects are achieved.

[0029] (1) A semiconductor module 100 includes a circuit body 1 having a semiconductor element 10 and a plurality of external terminals 2 connected to the semiconductor element 10, a substrate 5 having a power wiring layer 3 connected to the plurality of external terminals 2, an insulating filling member 12 covering the connection between the plurality of external terminals 2 and the power wiring layer 3, a cooler 7 having one side on which the circuit body 1 and the substrate 5 are mounted, and a heat dissipation member 4 disposed between the cooler 7 and the substrate 5, wherein the heat dissipation member 4 forms a frame 4a on the cooler 7 so as to surround the outer periphery of the area on which the circuit body 1 is mounted, and the filling member 4 is filled on the inner periphery of the frame 4a. In this way, a semiconductor module 100 can be provided which achieves both improved cooling performance of the substrate 5 and high-density terminal wiring.

[0030] (2) The substrate 5 has through holes 14 on the inner periphery side of the frame portion 4a for filling with the filler 12. This can improve the reliability of the filling result of the filler 12.

[0031] (3) The circuit body 1 is disposed inside the through-hole 14 provided in the substrate. In this manner, the circuit body 1 is insulated from surrounding electrical components and protected from foreign matter by the filler member 12 filled in the through-hole 14.

[0032] (4) A portion of the substrate 5 is disposed to cover the circuit body 1. This allows the substrate 5 to function as a lid for the circuit body 1, making it easier for the filler 12 to be applied from the through-holes 14 provided in the remaining substrate 5, improving the reliability of the filling results.

[0033] (5) The fixing member 15 fastening the substrate 5 and the cooler 7 is provided, and the fixing member 15 is disposed on the inner circumferential side of the frame portion 4a. This makes it possible to improve the adhesion between the substrate 5 and the heat dissipation member 4 and between the insulating member 6 and the heat dissipation member 4, and to prevent the filling member 12 from flowing out. Furthermore, the through-holes 14 in the insulating member 6 created (formed) by the fixing member 15 are filled with the filling member 12, and the cooler 7 and the substrate 5, and the cooler 7 and the circuit body 1 are insulated from each other.

[0034] (6) A second cooler 7a is provided on the top surface of the circuit body 1, and the second cooler 7a is positioned so as not to overlap with the through-holes 14 of the substrate 5 into which the filler 12 is filled. By doing so, the circuit body 1 is cooled from the top surface as well, which further suppresses the temperature rise of the semiconductor elements inside the circuit body 1 and improves the reliability of the circuit body 1. Furthermore, it becomes possible to fill the filler 12 in a state in which the cooler 7 and the second cooler 7a are assembled to the substrate 5 and the circuit body 1, and further, it becomes possible to visually check the filling state of the filler 12.

[0035] The present invention is not limited to the above-described embodiments, and various modifications and combinations of other configurations are possible without departing from the spirit of the present invention. Furthermore, the present invention is not limited to those having all of the configurations described in the above-described embodiments, and includes those in which some of the configurations are omitted. [Explanation of symbols]

[0036] 1: Circuit body 2: External terminal 3: Power wiring layer 4: Heat dissipation material 4a: Frame 5: Circuit board 6: Insulating material 6a: Second insulating member 7:Cooler 7a:Second cooler 8: Refrigerant 9: Conductive material 10: Semiconductor element 11: Sealing resin 12: Filler material 13: Heat transfer material 13a: Second heat transfer member 14:Through hole 15: Fixing member 100: Substrate-integrated semiconductor module

Claims

1. a circuit body having a semiconductor element and a plurality of external terminals connected to the semiconductor element; a substrate having a power wiring layer connected to the plurality of external terminals; an insulating filler member covering the connection portions between the plurality of external terminals and the power wiring layer; a cooler on one side of which the circuit body and the substrate are mounted; a heat dissipation member disposed between the cooler and the substrate, the heat dissipation member forms a frame portion on the cooler so as to surround the outer periphery of an area where the circuit body is mounted, The inner circumferential side of the frame portion is filled with the filling member, the substrate has a through hole for filling the filling member on an inner peripheral side of the frame portion, The through hole is larger than the circuit body in a planar direction. Semiconductor module.

2. 2. The semiconductor module according to claim 1, The circuit body is disposed inside the through hole provided in the substrate. Semiconductor module.

3. 3. The semiconductor module according to claim 2, A portion of the substrate is disposed to cover the circuit body. Semiconductor module.

4. 2. The semiconductor module according to claim 1, a fixing member that fastens the substrate and the cooler, The fixing member is disposed on the inner circumferential side of the frame portion. Semiconductor module.

5. 2. The semiconductor module according to claim 1, a second cooler is provided on the upper surface of the circuit body; When viewed from the thickness direction of the substrate, the second cooler is disposed at a position that does not overlap with a portion of the through hole of the substrate filled with the filling member where the circuit body is not disposed. Semiconductor module.

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