Power converter

Abstract

To provide a power conversion device that compatibly secures insulation reliability, improves heat dissipation, and is made compact.SOLUTION: A power conversion device comprises a semiconductor device and a wiring board. The wiring board has a through hole, and a heat spreader of the semiconductor device and a part of insulation resin are arranged passing through the through hole to protrude to the other face of the wiring board. The semiconductor device has a flange part, at least one of a gap between an inner peripheral surface of the through hole and the insulation resin of the semiconductor device in the through hole and a gap between the one surface of the wiring board and the flange part is filled with a first resin material, and the one surface of the wiring board is coated with a second resin material covering at least a connection part between an external terminal and an electric power wiring layer.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a power conversion device.

Background Art

[0002] In recent years, from the viewpoints of effective utilization of resources, promotion of energy conservation, and suppression of greenhouse gas emissions, power conversion devices using power semiconductor devices are widely used in various fields such as consumer, automotive, railway, industrial, and infrastructure applications. For example, in the automotive field, electric vehicles (EVs) and hybrid cars (HEVs) that combine motor drive and engine drive are typical. In an HEV that runs by assisting the driving force of the engine with the driving force of the motor, an EV runs solely on the driving force of the motor, which is purely electric power. Therefore, for the popularization of EVs, a power conversion device that can handle larger power is required.

[0003] A power conversion device used in an EV has, for example, the problem of expanding the cruising range, and it is necessary to increase the capacity of the mounted battery. When this capacity is increased, the size of the battery expands and the weight increases. Therefore, as battery technology development, efforts are being made to increase the energy density to achieve a large capacity in a small and lightweight form. Also, not only for batteries, when the volume and weight of the power conversion device increase, the power consumption performance of the vehicle (the travelable distance for a certain amount of power) and the driving performance, which is a basic performance of the vehicle such as running, turning, and stopping, deteriorate. Therefore, miniaturization and weight reduction of the entire drive system, mainly the motor and the power conversion device, are also required.

[0004] The main components of a power conversion device are power semiconductor devices (power modules) consisting of power semiconductor elements such as IGBTs (Insulated Gate Bipolar Transistors) and SiC-MOSFETs (Silicon Carbide-Metal-Oxide-Semiconductor Field-Effect Transistors). Power semiconductor devices are electronic components that handle high voltages and large currents compared to ordinary electronic circuits. When the current is increased, the losses increase proportionally to the square of the current, and the amount of heat generated increases. To reduce this heat generation, it is necessary to increase the amount of conductor used in the power conversion device to lower the conductor resistance, and to cool the heat generated by the circuit components while mounting them on a printed circuit board.

[0005] For example, Patent Document 1 discloses a semiconductor device configuration in which an opening is provided in the housing, and a heat spreader is placed in the opening of the housing to cool the heat generated by the electronic component. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Patent No. 5898575 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] In conventional technology, when a structure is used to insulate the terminals of a power module mounted in an opening of a printed circuit board with a resin coating, ensuring insulation reliability has been a challenge due to resin leakage and void formation during resin filling of the gap between the board and the terminals. In view of this, the present invention aims to provide a power conversion device that simultaneously ensures insulation reliability, improves heat dissipation, and achieves miniaturization. [Means for solving the problem]

[0008] The power converter comprises a semiconductor device having an external terminal protruding from the insulating resin, in which a semiconductor element and a heat spreader are sealed with an insulating resin, and a wiring board on which the semiconductor device is mounted and which has a power wiring layer connected to the external terminal, wherein the wiring board has a through hole, and the semiconductor device is arranged on one side of the wiring board such that the external terminal and the power wiring layer are connected, and the heat spreader and a part of the insulating resin of the semiconductor device protrude through the through hole to the other side of the wiring board, and the semiconductor device has a flange portion that faces or contacts the one side of the wiring board so as to cover the opening edge of the through hole on the one side of the wiring board, and at least one of the gap between the inner circumferential surface of the through hole and the insulating resin of the semiconductor device in the through hole, or the gap between the one side of the wiring board and the flange portion is filled with a first resin material, and a second resin material is applied to one side of the wiring board so as to at least cover the connection portion between the external terminal and the power wiring layer. [Effects of the Invention]

[0009] We can provide a power conversion device that simultaneously ensures insulation reliability, improves heat dissipation, and achieves miniaturization. [Brief explanation of the drawing]

[0010] [Figure 1] These are a plan view and a cross-sectional view showing an example of a power conversion device using conventional technology. [Figure 2] This figure shows the first problem with power conversion devices using conventional technology. [Figure 3] This figure shows the second challenge regarding power conversion devices using conventional technology. [Figure 4] This is a diagram of a power converter representing one embodiment of the present invention. [Figure 5] This is a cross-sectional view of a power semiconductor device used in the power conversion device of the present invention. [Figure 6] This is a cross-sectional view of a printed circuit board used in the power conversion device of the present invention. [Figure 7]This figure shows a modified example of the present invention. [Figure 8] This figure shows the manufacturing process of the power conversion device of the present invention. [Figure 9] This figure shows the manufacturing process of a modified power conversion device according to the present invention. [Figure 10] This figure shows the results of partial discharge tests for a power conversion device, an embodiment of the present invention, a modified example, and a prior art example shown in Figures 2 and 3. [Figure 11] This is a cross-sectional view showing a configuration in which the power conversion device of the present invention is equipped with coolers on the top and bottom.

[0011] Embodiments of the present invention will be described below with reference to the drawings. The following description and drawings are illustrative for illustrating the present invention, and have been omitted and simplified as appropriate for clarity of explanation. The present invention can also be carried out in various other forms. Unless otherwise specified, each component may be singular or plural.

[0012] The positions, sizes, shapes, and ranges of the components shown in the drawings may not represent their actual positions, sizes, shapes, and ranges in order to facilitate understanding of the invention. Therefore, the present invention is not necessarily limited to the positions, sizes, shapes, and ranges disclosed in the drawings.

[0013] (An embodiment of the present invention and the overall configuration of the apparatus) (Figure 1) Figure 1(a) is a cross-sectional view of a conventional power converter, and Figure 1(b) is a plan view of a conventional power converter from an overhead perspective. The power converter 100 consists of a power semiconductor device 10 (power module), a printed circuit board 20 (hereinafter referred to as the board 20), busbars, capacitors, etc. Note that the inner wiring layers of the board 20 are omitted and not shown in the figure.

[0014] The power conversion device 100 is a device that converts the DC DC DC voltage of a battery into a pseudo AC voltage by switching a power semiconductor device 11 and drives a motor with high efficiency using this AC voltage. The power semiconductor device 11 includes, for example, an IGBT or the like. When the power semiconductor device 11 switches with a large current, the power module generates heat. Also, the substrate 20, the bus bar, and the capacitor each generate heat in proportion to the square of the current flowing through them due to the loss of the electrical resistance component of each material.

[0015] In a conventional power conversion device 100, a power semiconductor device 10 (hereinafter referred to as semiconductor device 10) is disposed on a substrate 20 provided with through holes. A gap 41 is formed between the semiconductor device 10 and the substrate 20. The semiconductor device 10 has a power semiconductor device 11 and heat spreaders 12 and 13 sealed with an insulating resin 16, and also has external terminals 15 protruding from the insulating resin 16. The semiconductor device 11 and the heat spreader 13 are joined by a joining material 14. Resin frames 32 are formed at both ends of the substrate 20 on which the semiconductor device 10 is mounted by a non-flowing resin material. The substrate 20 has a power wiring layer 22, which is a circuit conductor connected to the external terminals 15, an insulating layer 21, and through holes 23. The external terminals 15 are inserted into the through holes 23 formed in the substrate 20, and a joining material 30 such as melted solder fills the through holes 23, thereby being joined and fixed within the through holes 23. As a result, the power wiring layer 22 of the substrate 20 and the semiconductor device 10 are electrically connected via the external terminals 15.

[0016] The semiconductor device 10 handles currents ranging from a few amperes for small ones to several hundred amperes for large ones, depending on its output capacitance. In particular, in the case of the semiconductor device 10 handling a large current of several hundred amperes, the width between the external terminals 15 becomes several millimeters to several tens of millimeters wide. To miniaturize such a power conversion device 100 and the semiconductor device 10, it is necessary to reduce the insulation distance between the terminals 15 of the semiconductor device 10 and, correspondingly, reduce the insulation distance between the wirings 22 of the substrate 20. Regarding the insulation distance, there are standards such as IEC60664-1. For the non-resin-sealed external terminals 15 and wirings 22, a spatial distance and a creepage distance along this standard are required. To make the insulation distance even smaller than this, resin sealing of the external terminals 15 and wirings 22 is necessary.

[0017] (Figure 2) The problems when resin-sealing a conventional semiconductor device 100 are cited. The power conversion device 100C is obtained by applying a resin material 34 to the substrate 20 and the external terminals 15 of the semiconductor device 10 in the conventional power conversion device 100. The resin material 34 with a viscosity of 0.5 Pa·s at 25°C was adopted and applied to cover the wiring layer 22 and the external terminals 15 of the substrate 20. Thereafter, the resin material 34 is cured under predetermined conditions. However, during the application or curing of the resin material 34, the resin material 34 flows down from the gap between the substrate 20 and the semiconductor device 10, resulting in a resin leak 35. Thus, when the viscosity of the resin material 34 is lower than a predetermined standard, there is a problem that the external terminals 15 cannot be covered with the resin material 34.

[0018] (Figure 3) Another problem when resin-sealing a conventional power conversion device 100 is cited. The power conversion device 100D is obtained by applying a resin material 34 to the substrate 20 and the external terminals 15 of the semiconductor device 10 in the conventional power conversion device 100. However, the resin material 34 with a viscosity of 30 Pa·s at 25°C, which has a higher viscosity than that in Figure 2, was adopted. Thereafter, the resin material 34 is cured under predetermined conditions. Different from Figure 2, although resin leakage from the gap between the substrate 20 and the semiconductor device 10 can be prevented, a space (void) 36 where the resin 34 is not filled is formed in the gap between the external terminals 15 and the substrate 20.

[0019] Thus, when voids 36 are formed due to a higher viscosity of the resin material 34 than a predetermined standard, a high electric field is applied to the voids 26 between the terminals 15 and between the terminals 15 and the wiring 22 when a high voltage is applied, due to the relationship between the relative permittivity of the resin 34 and the voids 26. When the electric field becomes high, partial discharge occurs in the voids 26, and partial discharge degradation progresses in the resin material 34, potentially leading to dielectric breakdown between the terminals 15 and between the terminals 15 and the wiring 22.

[0020] (Figures 4, 5, and 6) Figure 4(a) is a cross-sectional view of a power converter 100A according to one embodiment of the present invention, Figure 4(b) is an overhead plan view of the power converter 100A, and Figure 4(c) is a plan view seen from below. In order to resolve the problems that arose with conventional power converters 100C and 100D, the power converter 100A of the present invention adopts the following configuration.

[0021] The semiconductor device 10 is connected to an external terminal 15 and a power wiring layer 22 on one side of the substrate 20, and a portion of the heat spreader 13 and insulating resin 16 of the semiconductor device 10 are arranged to protrude to the other side of the substrate 20 through a through hole 24 (Figure 6). The gap between the heat spreader 12 and the substrate 20 formed when the heat spreader 12 is inserted into the through hole 24 provided in the substrate 20 is made wider closer to the surface of the heat spreader 12 (the side not covered by the resin material 31) (gap 41a) and narrower closer to the substrate 20 (gap 41b) by giving the insulating resin 16 of the semiconductor device 10 an inclination. In other words, the gap between the insulating resin 16 and the through hole 24 widens in the direction in which the insulating resin 16 of the semiconductor device 10 protrudes to the other side of the substrate 20 through the through hole 24. This makes it easier to fill with the first resin material 31, and narrowing the gap closer to the substrate 20 improves the resin's ability to fill.

[0022] Furthermore, the semiconductor device 10 has a flange portion 16a that faces or contacts one side of the substrate 20, so as to cover the opening edge of the through hole 24 on one side of the substrate 20 (Figure 5). The first resin material 31 is filled in at least one of the gaps between the inner circumferential surface of the through hole 24 and the insulating resin 16 of the semiconductor device 10 inside the through hole 24, or the gap between one side of the substrate 20 and the flange portion 16a. In addition, a second resin material 33 is applied to one side of the substrate 20, at least covering the connection portion between the external terminal 15 and the power wiring layer 22.

[0023] The second resin material 33 uses a resin material that has higher fluidity in the molten state than the first resin material 31. In addition, a resin frame 32 is formed on the edge of the surface of the substrate 20 to which the second resin material 33 is applied (one side of the substrate 20), and the first resin material 31 and the second resin material 33 use low-elasticity resins that are softer than the resin material used to form the resin frame 32 and the insulating resin 16 of the semiconductor device 10. Examples of high-fluidity resin materials used for the second resin material 33 include silicone and epoxy. In this way, cracks that form between the resin materials 31, 33 and the substrate 20, and between the resin materials 31, 33 and the insulating resin 16 of the semiconductor device can be suppressed.

[0024] By using the above configuration, the resin material (second resin material 33) can be cured without leakage 35 of the resin material from the gap 41 between the semiconductor device 10 and the substrate 20, and a power converter 100A can be provided that can cover the external terminals 15 with the second resin material 33. The curing of the first resin material 31 and the second resin material 33 may be done by leaving them to cure at room temperature (room temperature curing type resin material), or by applying heat of 120°C (heat curing type resin material).

[0025] Furthermore, by using a resin material with a lower viscosity than the first resin material 31 for the second resin material 33, the resin can be filled into the gap between the wide external terminals 15 and the substrate 20 without generating voids 36. This prevents partial discharge even when high voltage is applied, ensuring insulation reliability. With this improved insulation reliability, the insulation distance can be further reduced, enabling miniaturization of the power converter 100A.

[0026] (modified version) (Figure 7) In the power converter 100B, a modified example of the present invention, the first resin material 31 is formed only in the gap between one side of the substrate 20 and the flange portion 16a (see Figure 5) of the semiconductor device 10, while the second resin material 33 is used to coat the remaining part of the substrate 20. Even if the coating distribution of the first resin material 31 and the second resin material 33 on the substrate 20 is changed in this way, the formation of resin leakage 35 and voids 36 can be prevented.

[0027] (Method for creating a power converter) (Figure 8) The method for creating the power converter 100A will be explained using Figures 8(a) to 8(e). First, the method for creating the semiconductor device 10 and circuit board 20 required for the power converter 100A will be described. Note that the diagrams explaining each process are omitted, and explanations of the mounted components should be found in Figures 5 and 6.

[0028] First, the semiconductor device 10 is constructed by bonding a power semiconductor element 11 to a heat spreader 12 via a bonding agent (solder) 14, and electrically connecting the gate electrode of the power semiconductor element 11 to the external terminal 15 using a wire (not shown in the figure). Next, a heat spreader 13 is bonded to the opposite side of the power semiconductor element 11 from the side bonded to the heat spreader 12 via the bonding agent 14. Then, with the sides of the heat spreaders 12 and 13 opposite to the side bonded to the power semiconductor element 11 exposed, the power semiconductor element 11 and the heat spreaders 12 and 13 are sealed with insulating resin 16 using transfer molding. Finally, the external terminal 15 is bent to complete the semiconductor device 10. The heat spreader 12 and the external terminal 15 are integrally molded in a lead frame.

[0029] Next, a multilayer printed circuit board 20 having four wiring layers is prepared. Since the power converter 100A handles several hundred amperes of current, 200 μm thick copper foil (thicker than the copper foil commonly used in electronic equipment) is used for the wiring layers 22 of the board 20. A glass fiber reinforced epoxy resin substrate is used for the insulating layer 21 of the board 20. Each wiring layer 22 of the board 20 is pre-etched with copper foil to form the circuit of the power converter 100. Through holes 24 for the placement of the semiconductor device 10 and through holes 23 for inserting external terminals 15 are formed in the board 20, completing the board 20.

[0030] Based on the completed semiconductor device 10 and substrate 20, the method for creating the power converter 100A will be explained. In Figure 8(a), the semiconductor device 10 is placed in the through-hole 24 of the substrate 20 with the heat spreader 12 side facing the insertion side (bottom side). The external terminal 15 of the semiconductor device 10 is inserted into the through-hole 23 of the substrate 20. Next, in Figure 8(b), molten solder 30 is poured into the through-hole using a flow soldering device to electrically connect the through-hole 23 and the external terminal 15. Next, in Figure 8(c), the semiconductor device 10 and substrate 20 are turned over, and a first resin material 31 with a viscosity of 30 Pa·s at 25°C is filled into the gap between the semiconductor device 10 and the substrate 20. The first resin material 31 is then applied to cover the wiring layer 22 of the substrate 20, and the first resin material 31 is cured under predetermined conditions. Here, the surface (first surface 12a) of the heat spreader 12 of the semiconductor device 10 that protrudes from the other side of the substrate 20 is positioned outside the other side of the substrate 20 so that it is not covered by the first resin material 31. In this way, neither the first resin material 31 nor the second resin material 33 is formed on the first surface 12a.

[0031] Next, in Figure 8(d), the semiconductor device 10 and the substrate 20 were inverted to the same state as in Figure 8(b), and a resin frame 32 was formed on the edge of the surface of the substrate 20 that had not been coated with resin material 31 using a non-flowing resin material. Then, in Figure 8(e), the second resin material 33, which has a viscosity of 0.5 Pa·s at 25°C, was applied to the substrate 20 to a height that covered the wiring layer 22, and the resin material 33 was cured under predetermined curing conditions to complete the power converter 100A. Note that by including different amounts of fillers in the first resin material 31 and the second resin material 33, the same manufacturing method can be carried out using the same resin materials. In this case, the first resin material 31 needs to have a higher viscosity than the second resin material 33, so the filler content of the first resin material 31 is greater than the filler content of the second resin material 33. Fillers are powder components such as aluminum and silica, and the higher the content, the higher the viscosity.

[0032] (Manufacturing method of a modified power converter) (Figure 9) The method for manufacturing the power converter 100B will be explained using Figures 9(a) to 9(h). Note that the manufacturing methods for the semiconductor device 10 and the substrate 20 of the power converter 100B are the same as those for the power converter 100A described in Figure 8. In Figure 9(a), a first resin material 31 with a viscosity of 100 Pa·s at 25°C was applied to the surface of the substrate 20 facing the flange portion 16a of the semiconductor device 10 around the through-hole 24. Next, in Figure 9(b), the semiconductor device 10 was positioned in the through-hole 24 of the substrate 20 with the lower heat spreader 12 side facing downwards, and the external terminals 15 of the semiconductor device 10 were inserted into the through-hole 23 of the substrate 20. The first resin material 31 was then cured under predetermined conditions to fix the semiconductor device 10 and the substrate 20, and to seal the gap between the semiconductor device 10 and the substrate 20.

[0033] Next, in Figure 9(c), molten solder 30 was poured into the through-hole 23 using a flow soldering device, electrically joining the through-hole 23 to the external terminal 15. Next, in Figure 9(d), a resin frame 32 was formed on the edge of one side of the substrate 20 (the side where the first resin material 31 is formed and the flange portion 16a of the semiconductor device 10 is in contact) using a non-flowing resin material. In Figure 9(e), a second resin material 33 with a viscosity of 0.5 Pa·s at 25°C was applied to the substrate 20 to a height that covered the wiring layer 22, and the resin material 33 was cured under predetermined curing conditions. In Figure 9(f), the semiconductor device 10 and the substrate 20 were inverted, and a resin frame 32 was also formed on the edge of the other side of the substrate 20 using a non-flowing resin material. In Figure 8(g), a second resin material 33 with a viscosity of 0.5 Pa·s at 25°C was applied to the substrate 20 to a height that covered the wiring layer 22, and the resin material 33 was cured under predetermined curing conditions. In Figure 9(h), after the resin material 33 has hardened, the semiconductor device 10 and the substrate 20 are rotated 180 degrees again to complete the power converter 100B.

[0034] (Figure 10) To verify the effectiveness of the insulation reliability of the power converter 100A according to the present invention, the modified power converter 100B, and the conventional power converters 100C and 100D, partial discharge tests were conducted, and the results are described below.

[0035] In the partial discharge test, an AC voltage was applied between the external terminals 15 of the semiconductor device 10 using a partial discharge measuring device. As the AC voltage was gradually increased from 0V, the voltage at which partial discharge occurred (partial discharge initiation voltage) was measured for each sample. Since the external terminals 15 of the semiconductor device 10 are inserted into through-holes 23 of the substrate 20 and joined with solder, the voltage is also applied to the wiring 22 of the substrate 20. The threshold for determining that partial discharge has occurred was set at 10 pC, and the maximum test voltage for partial discharge was set at 2.5 kVrms.

[0036] Figure 10(a) shows the test results for the power converter 100A. The test results showed that the second resin material 33 could be filled without any voids 36, both above the external terminal 15 of the semiconductor device 10 and in the gap between the external terminal 15 and the substrate 20, so no partial discharge occurred. Furthermore, no partial discharge occurred even at the maximum test voltage of 2.5kVrms, and there was no dielectric breakdown.

[0037] Figure 10(b) shows the test results for power converter 100B. Similar to power converter 100A, the test results showed that the second resin material 33 could be filled without voids 36, both above the external terminal 15 of the semiconductor device 10 and in the gap between the external terminal 15 and the substrate 20, thus preventing partial discharge. Furthermore, no partial discharge occurred even at the maximum test voltage of 2.5 kVrms, nor was there any dielectric breakdown.

[0038] Figure 10(c) shows the test results for the power converter 100C. The test results showed that a discharge of 1000 pC or more was detected at a voltage exceeding 1.7 kVrms. In addition, dielectric breakdown (flashover) occurred between the external terminals 15. This is thought to be due to surface discharge occurring between the external terminals 15 because the resin material 34 leaked from the gap between the semiconductor device 10 and the substrate 20, exposing the external terminals 15.

[0039] Figure 10(d) shows the test results for the power converter 100D. In the test results, partial discharge began to occur at voltages exceeding 1.7kVrms, and the threshold of 10pC for partial discharge was exceeded at 1.8kVrms. Subsequently, the voltage was increased to 2.0kVrms, at which point the discharge charge amount was approximately 40pC, and even at the maximum test voltage of 2.5kVrms, the discharge charge amount remained at approximately 40pC, and dielectric breakdown did not occur. This is thought to be because the upper part of the external terminals 15 is covered with resin material, so dielectric breakdown between the external terminals 15 did not occur, but partial discharge occurred because a void 36 was formed beneath the external terminals 15. Certainly, dielectric breakdown does not occur in short-term insulation tests, but in actual use, if high voltage is applied for a long period of time, the resin material or the insulating layer 21 of the substrate 20 may undergo partial discharge degradation, and in the worst case, dielectric breakdown may occur.

[0040] As described above, the power converters 100A and 100B of the present invention have superior insulation reliability compared to the conventional power converters 100C and 100D. Thus, the present invention allows for smaller insulation distances between external terminals 15 and between wiring 22 on the substrate 20. This contributes to reducing the main circuit inductance and miniaturization. In addition, power semiconductor elements 11 with high voltage resistance may be applied to the semiconductor device 10 and the power converters 100A and 100B.

[0041] (Figure 11) Coolers 51 are provided on both sides of the power converter 100A of the present invention, and an electrically insulating heat dissipation agent 52 is provided between the power converter 100A and the coolers 51. In this way, the power converter 100A of the present invention can be mounted on vehicles such as EVs and HEVs.

[0042] According to the embodiment of the present invention described above, the following effects are achieved.

[0043] (1) The power converter 100A comprises a semiconductor device 10 having semiconductor elements 11 and heat spreaders 12, 13 sealed in insulating resin 16 and external terminals 15 protruding from the insulating resin 16, and a wiring board 20 on which the semiconductor device 10 is mounted and which has a power wiring layer 22 connected to the external terminals 15. The wiring board 20 has through holes 24, and the semiconductor device 10 is arranged such that the external terminals 15 and the power wiring layer 22 are connected on one side of the wiring board 20, and a portion of the heat spreader 12 and insulating resin 16 of the semiconductor device 10 protrudes through the through holes 24 to the other side of the wiring board 20. The semiconductor device 10 has a flange portion 16a that faces or contacts one side of the wiring board 20 so as to cover the opening edge of the through hole 24 on one side of the wiring board 20. The gap 41 between the inner circumferential surface of the through hole 24 and the insulating resin 16 of the semiconductor device 10 inside the through hole 24, or at least one of the gaps between one side of the wiring board 20 and the flange portion 16a, is filled with the first resin material 31. The second resin material 33 is applied to one side of the wiring board 20, at least covering the connection between the external terminal 15 and the power wiring layer 22. In this way, a power conversion device 100A can be provided that simultaneously ensures insulation reliability, improves heat dissipation, and reduces size.

[0044] (2) The second resin material 33 is a resin material that has higher fluidity in the molten state than the first resin material 31. This prevents resin leakage from the gap between the substrate 20 and the flange portion 16a of the semiconductor device 10.

[0045] (3) As the insulating resin 16 protrudes through the through hole 24 to the other side of the wiring board 20, the gap between the insulating resin 16 and the through hole 24 widens. This prevents resin leakage from the gap between the substrate 20 and the flange portion 16a of the semiconductor device 10.

[0046] (4) The heat spreader 12 has a first surface 12a that protrudes to the other side of the wiring board 20, which is positioned outside the other side of the wiring board 20, and the first resin material 31 or the second resin material 33 is not formed on the first surface 12a. This prevents the formation of resin material on the heat spreader surface 12a.

[0047] (5) The first resin material 31 and the second resin material 33 contain fillers, and the filler content of the first resin material 31 is greater than the filler content of the second resin material 33. In this way, even if the same resin material is used for the first resin material 31 and the second resin material 33, the viscosity can be differentiated by the filler content.

[0048] (6) The wiring board 20 has a resin frame 32 formed at the edge of the surface to which the second resin material 33 is applied, and the first resin material 31 and the second resin material 33 are resins with lower elasticity than the resin material used to form the resin frame 32 and the insulating resin 16 of the semiconductor device 10. This makes it possible to suppress cracks that form between the resin materials 31, 33 and the substrate 20, or between the resin materials 31, 33 and the insulating resin 16 of the semiconductor device.

[0049] It should be noted that the present invention is not limited to the embodiments described above, and various modifications and combinations of other configurations can be made without departing from the spirit of the invention. Furthermore, the present invention is not limited to having all the configurations described in the embodiments described above, and may also include configurations in which some of those configurations are omitted. [Explanation of symbols]

[0050] 10: Power semiconductor device 11: Power semiconductor devices 12: Heat spreader (collector side of IGBT) 12a: First face 13: Heat spreader (emitter side of IGBT) 14: Bonding material 15: External terminals 16: Insulating resin 16a: Flange section 20: Printed circuit board 21: Insulating layer of printed circuit board 22: Circuit conductors (power wiring layer) of printed circuit boards 23: Through-hole 24: Through-holes in printed circuit boards 30: Joining material (solder) 31: First resin material 32: Resin frame 33: Second resin material 34: Resin material (conventional) 35: Leakage of resin material 36: Unfilled portion of resin (void) 41: Gap between power semiconductor device and printed circuit board 41a: Gap near the first surface 41b: Gap close to the substrate 51:Cooler 52: Electrically insulating heat dissipation material 100: Conventional power conversion device 100A: Power conversion device of the present invention 100B: Modified Power Converter 100C: Power converters facing the first challenge 100D: Power converters face a second challenge.

Claims

1. A semiconductor device having a semiconductor element and a heat spreader sealed with an insulating resin, and external terminals protruding from the insulating resin, The semiconductor device is mounted on a wiring board having a power wiring layer connected to the external terminals, The aforementioned wiring board has through holes, The semiconductor device is arranged such that the external terminals and the power wiring layer are connected on one side of the wiring board, and a portion of the heat spreader and insulating resin of the semiconductor device protrudes through the through hole to the other side of the wiring board. The semiconductor device has a flange portion that faces or contacts the one side of the wiring board so as to cover the opening edge of the through hole on the one side of the wiring board, At least one of the gaps between the inner circumferential surface of the through hole and the insulating resin of the semiconductor device within the through hole, or the gap between one side of the wiring board and the flange portion, is filled with the first resin material. A second resin material is applied to one side of the wiring board, at least covering the connection between the external terminal and the power wiring layer. Power converter.

2. A power conversion device according to claim 1, The second resin material is a resin material that has higher fluidity in a molten state than the first resin material. Power converter.

3. A power conversion device according to claim 1, The gap between the insulating resin and the through-hole widens in the direction in which the insulating resin protrudes through the through-hole to the other side of the wiring board. Power converter.

4. A power conversion device according to claim 1, The heat spreader has a first surface that protrudes to the other side of the wiring board, and is positioned outside the other side of the wiring board. The first resin material or the second resin material is not formed on the first surface. Power converter.

5. A power conversion device according to claim 1, The first resin material and the second resin material contain fillers, and the filler content of the first resin material is greater than the filler content of the second resin material. Power converter.

6. A power conversion device according to any one of claims 1 to 5, The wiring board has a resin frame formed at the edge of the surface to which the second resin material is applied. The first resin material and the second resin material are resins with lower elasticity than the resin material used to form the resin frame and the insulating resin of the semiconductor device. Power converter.

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