Power conversion device

Abstract

A power conversion device according to the present invention comprises a semiconductor device and a printed circuit board. The printed circuit board has a through-hole, and a portion of an insulating resin and a heat spreader of the semiconductor device are arranged such that they extend through the through-hole and project onto the other side of the printed circuit board. The semiconductor device has a flange portion. A gap between the inner circumferential surface of the through-hole and the insulating resin of the semiconductor device within the through-hole and / or a gap between one side of the printed circuit board and the flange portion is filled with a first resin material, and a second resin material, which covers at least one connection between an external terminal and a power wiring layer, is applied to one side of the printed circuit board.

Description

Technical area

[0001] The present invention relates to a power conversion device. State of the art

[0002] In recent years, power conversion devices using power semiconductor elements have been widely used in various fields, such as consumer use, automobile use, railway use, industrial use, and infrastructure use, from the perspectives of effective resource utilization, promoting energy conservation, and suppressing greenhouse gas emissions. Representative examples of automobile use include electric vehicles (EVs) and hybrid vehicles (HEVs), which combine motor propulsion and internal combustion engine propulsion. Unlike HEVs, which propel by assisting the motor with the internal combustion engine's propulsion power, EVs propel only by the motor's propulsion power, and the propulsion power is purely electric.Thus, a power conversion device capable of handling larger electrical power is required for widespread use of the EV.

[0003] For example, the power conversion device used in the EV is required to increase the driving distance of the EV, and thus, the capacity of a battery to be mounted must be increased. Increasing the capacity causes an increase in the size of the battery and an increase in the weight of the battery, so increasing the capacity with a small size and light weight due to an increase in energy density has been promoted as a technology development of the battery. Increasing the volume and weight of not only the battery but also the power conversion device causes a deterioration not only in the electric cost performance (a driving distance per a certain electric power) of an automobile, but also in the driving performance, which is a basic performance of the automobile, such as driving, turning, and stopping.Thus, it is also required to reduce the size and weight of an entire drive system, which mainly includes the engine and the power conversion device.

[0004] The power conversion device mainly consists of a power semiconductor device (power module) that includes a power semiconductor element such as an insulated-gate bipolar transistor (IGBT) or a silicon carbide metal oxide semiconductor field-effect transistor (SiC MOSFET). The power semiconductor device is an electronic component that handles high voltage and large current compared to a normal electronic circuit. As a current increases, the loss increases proportionally to the square of the current, increasing a heating value. Reducing this heat generation requires not only reducing the conductor resistance by increasing the volume of conductors used in the power conversion device, but also reducing the heat generation of a circuit component by cooling the circuit component while the circuit component is mounted on a circuit board.

[0005] For example, PTL 1 discloses a configuration of a semiconductor device in which an opening is provided in a case to allow a heat spreader to be arranged in the opening of the case, thereby reducing heat generation of an electronic component by cooling. Citation listPatent literature

[0006] PTL 1: JP 5898575 B2 Summary of the inventionTechnical problem

[0007] Conventional techniques have a problem in ensuring insulation reliability. When using a structure in which terminals of a power module mounted in an opening part of a circuit board are insulated by coating with resin, resin leaks and voids are formed during the resin filling process into a gap between the circuit board and the terminals. In view of this problem, an object of the present invention is to provide a power conversion device in which ensuring insulation reliability, improving heat dissipation, and miniaturization coexist. Solution to the problem

[0008] A power conversion device includes: a semiconductor device including a semiconductor element and a heat spreader sealed with an insulating resin, and an external terminal protruding from the insulating resin; and a circuit board equipped with the semiconductor device and including a power wiring layer connected to the external terminal. The circuit board includes a through-hole. The semiconductor device is arranged on one surface of the circuit board with the external terminal connected to the power wiring layer, while a part of the heat spreader and the insulating resin of the semiconductor device protrude through the through-hole to another surface of the circuit board.The semiconductor device includes a flange portion facing or in contact with one surface of the circuit board and covering an opening edge of the through-hole on the one surface of the circuit board. At least one of a gap between an inner peripheral surface of the through-hole and the insulating resin of the semiconductor device in the through-hole and a gap between the one surface of the circuit board and the flange portion is filled with a first resin material, and the one surface of the circuit board is coated with a second resin material, covering at least a connection portion between the external terminal and the power wiring layer. Advantageous effects of the invention

[0009] A power conversion device in which ensuring insulation reliability, improving heat dissipation, and miniaturization coexist can be provided. Short description of the drawings Fig. 1 is a plan view and a sectional view illustrating an example of a power conversion device using a conventional technique. Fig. 2 is a diagram illustrating a first problem of a power conversion device using a conventional technique. Fig. 3 is a diagram illustrating a second problem of a power conversion device using a conventional technique. [ Fig. 4] Fig. 4 is a diagram of a power conversion device according to an embodiment of the present invention. [ Fig. 5] Fig. 5 is a sectional view of a power semiconductor device used in the power conversion device of the present invention. [ Fig. 6] Fig. 6 is a sectional view of a circuit board used in the power conversion device of the present invention. [ Fig. 7] Fig. 7 is a diagram illustrating a modification of the present invention. [ Fig. 8] Fig. 8 is a diagram illustrating a manufacturing process of the power conversion device of the present invention. [ Fig. 9] Fig. 9 is a diagram illustrating a manufacturing process of a power conversion device according to a modification of the present invention. [ Fig. 10] Fig. 10 is a diagram showing partial discharge test results of the power conversion device of each of the embodiment and the modification of the present invention and the example of conventional techniques used in Fig. 2 and Fig. 3 are shown. [ Fig. 11] Fig. 11 is a sectional view illustrating a configuration in which coolers are individually provided above and below the power conversion device of the present invention.

[0010] Embodiments of the present invention will be described below with reference to the drawings. The description and the following drawings are examples for describing the present invention and have been omitted and simplified for clarity. The present invention may also be implemented in various other forms. Unless otherwise stated, each component may be singular or plural.

[0011] Each drawing shows a position, size, shape, range, and the like of each component, which may not represent the actual position, size, shape, range, and the like, in order to facilitate understanding of the invention. Thus, the present invention is not necessarily limited to the position, size, shape, range, and the like disclosed in each drawing. (An embodiment of the present invention and general configuration of the device) (Fig. 1)

[0012] Fig. 1(a) is a sectional view of a conventional power conversion device and Fig. 1(b) is a plan view of the conventional power conversion device from a top angle. A power conversion device 100 includes a power semiconductor device 10 (power module), a circuit board 20 (hereinafter referred to as a board 20), a bus bar, a capacitor, and the like. The board 20 is illustrated without a wiring layer of an inner layer by omitting the wiring layer.

[0013] The power conversion device 100 converts a DC voltage of a battery into a pseudo-AC voltage by switching the power semiconductor element 11, and drives a motor with high efficiency using the pseudo-AC voltage. The power semiconductor element 11 includes, for example, an IGBT. The power module generates heat by switching a large current in the power semiconductor element 11, and the plate 20, the bus bar, and the capacitor also generate heat proportional to the product of the square of each of the currents flowing through the respective components due to loss caused by an electrical resistance component of a material of a corresponding one of the respective components.

[0014] The power conversion device 100 using a conventional technique includes the power semiconductor device 10 (hereinafter referred to as a semiconductor device 10) arranged on the board 20 provided with a through-hole. A gap 41 is formed between the semiconductor device 10 and the board 20. The semiconductor device 10 includes the power semiconductor element 11 and heat spreaders 12 and 13 sealed with an insulating resin 16, and an external terminal 15 protruding from the insulating resin 16. The semiconductor element 11 and the heat spreader 13 are bonded to each other with a bonding material 14. The board 20, which is equipped with the semiconductor device 10, is provided at its opposite ends with respective resin frames 32 made of a non-flowable resin material.The board 20 includes a power wiring layer 22 serving as a circuit conductor connected to the external terminal 15, an insulation layer 21, and a through-hole 23. The external terminal 15 is inserted into the through-hole 23 formed in the board 20, and is connected and fixed in the through-hole 23 by filling the through-hole 23 with a connecting material 30, such as molten solder. As a result, the power wiring layer 22 of the board 20 and the semiconductor device 10 are electrically connected to each other through the external terminal 15.

[0015] The semiconductor device 10 handles a current ranging from a small current of several A to a large current of several hundred A depending on its output capacity. Specifically, the semiconductor device 10 for handling a large current of several hundred A has a width between the external terminals 15, with the width increasing by several mm to several tens of mm. Miniaturizing the power conversion device 100 and the semiconductor device 10 as described above requires a reduction in an insulation distance between the terminals 15 of the semiconductor device 10 and a corresponding reduction in an insulation distance between wirings 22 of the board 20. The insulation distance conforms to a standard such as IEC60664-1, and a space distance and a creepage distance according to this standard are required between the external terminals 15 and between the wirings 22 without being sealed with resin.A further reduction of the insulation distance requires a resin seal for the external terminals 15 and the wiring 22. (Fig. 2)

[0016] A problem to be solved for resin sealing performed on the semiconductor device 100 using a conventional technique will be described. A power conversion device 100C is configured by applying a resin material 34 to the board 20 and the external terminal 15 of the semiconductor device 10 in the power conversion device 100 using a conventional technique. The resin material 34 having a viscosity of 0.5 Pa*s at 25°C is used to be applied to cover the wiring layer 22 of the board 20 and the external terminal 15. Although the resin material 34 is then cured under predetermined conditions, the resin material 34 flows downward from a gap between the board 20 and the semiconductor device 10 during the application or curing of the resin material 34, thereby causing a leak 35 of the resin material.The resin material 34 having a viscosity lower than a predetermined standard as described above causes a problem that the external terminal 15 cannot be covered with the resin material 34. (Fig. 3)

[0017] Another problem to be solved for resin sealing performed on the power conversion device 100 using a conventional technique will be described. Although a power conversion device 100D is configured by applying the resin material 34 to the board 20 and the external terminal 15 of the semiconductor device 10 in the power conversion device 100 using a conventional technique, the resin material 34 is used with a viscosity of 30 Pa*s at 25°C, which is higher than that in Fig. 2 is used. Although the resin material 34 is then cured under predetermined conditions, in contrast to Fig. 2 prevents the resin material from leaking from the gap between the board 20 and the semiconductor device 10. However, a space (cavity) 36 is formed in the gap between the external terminal 15 and the board 20, and the space is not filled with the resin 34.

[0018] As described above, when the cavity 36 is formed with the resin material 34 having a viscosity higher than the predetermined standard, a high electric field is applied to the cavity 26 due to a relationship between the relative permittivities of the resin 34 and the cavity 26 when a high voltage is applied between the terminals 15 and between the terminals 15 and the wirings 22. An increase in an electric field causes a partial discharge in the cavity 26 to cause a progress of partial discharge deterioration in the resin material 34, so that dielectric breakdown may occur between the terminals 15 and between the terminals 15 and the wirings 22. (Fig. 4, Fig. 5 and Fig. 6)

[0019] Fig. 4(a) is a sectional view of the power conversion device 100A according to an embodiment of the present invention, Fig. 4(b) is a top plan view of the power conversion device 100A and Fig. 4(c) is a plan view as viewed from below. To solve the problems caused by the power conversion devices 100C and 100D using conventional techniques, the following configuration is used in the power conversion device 100A of the present invention.

[0020] The semiconductor device 10 includes: the external terminal 15 and the power wiring layer 22 connected to each other on a surface of the board 20; and the heat spreader 13 and the insulating resin 16 partially formed through a through hole 24 ( Fig. 6) are arranged extending to protrude toward the other surface of the board 20. When the heat spreader 13 is inserted into the through-hole 24 provided in the board 20, a gap is formed between the heat spreader 12 and the board 20 and includes a gap 41a that increases toward a surface of the heat spreader 12 (a surface not covered with a resin material 31) and a gap 41b that decreases toward the board 20 by inclining the insulating resin 16 of the semiconductor device 10. That is, the gap between the insulating resin 16 and the through-hole 24 increases along a direction in which the insulating resin 16 of the semiconductor device 10 protrudes through the through-hole 24 to the other surface of the board 20. This structure facilitates the filling of the first resin material 31 and improves the filling properties of the resin by narrowing the width toward the plate 20.

[0021] The semiconductor device 10 further includes a flange portion 16a facing or in contact with one surface of the plate 20 and covering an opening edge of the through-hole 24 in the one surface of the plate 20 ( Fig. 5). The first resin material 31 is filled into at least one of a gap between an inner peripheral surface of the through-hole 24 and the insulating resin 16 of the semiconductor device 10 in the through-hole 24, and a gap between one surface of the board 20 and the flange portion 16a. The one surface of the board 20 is coated with a second resin material 33 to cover at least a connection portion between the external terminal 15 and the power wiring layer 22.

[0022] As the second resin material 33, a resin material having higher fluidity in a molten state than the first resin material 31 is used. The board 20 includes a resin frame 32 at one end portion of the surface coated with the second resin material 33 (one surface of the board 20), and a resin material softer than a resin material used to form the resin frame 32 and the insulating resin 16 of the semiconductor device 10 is used for the first resin material 31 and the second resin material 33. Examples of the resin material with high fluidity used for the second resin material 33 include silicone and epoxy. As a result, cracks that are likely to form between the resin materials 31 and 33 and the board 20, and between the resin materials 31 and 33 and the insulating resin 16 of the semiconductor device, can be suppressed.

[0023] The above configuration makes it possible to provide the power conversion device 100A capable of: directly curing the resin material (the second resin material 33) without causing the resin material to leak 35 from the gap 41 between the semiconductor device 10 and the board 20; and covering the external terminal 15 with the second resin material 33. The first resin material and the second resin material can be cured using a method of directly leaving and curing the first resin material 31 and the second resin material 33 at room temperature (a room-temperature curing type resin material) or using a method of curing the first resin material and the second resin material by applying heat at 120°C (a heat-curing type resin material).

[0024] Using a resin material with a viscosity lower than that of the first resin material 31 for the second resin material 33 allows even a wide gap provided between the external terminal 15 and the board 20 to be filled with the resin material without creating the void 36. As a result, partial discharge can be prevented from occurring even when a high voltage is applied, and insulation reliability can be ensured. By improving insulation reliability as described above, an insulation distance can be further reduced to enable miniaturization of the power conversion device 100A. (Modification)(Fig. 7)

[0025] A power conversion device 100B according to a modification of the present invention is configured such that a first resin material 31 is disposed only in a gap part between a surface of a plate 20 and a flange part 16a (see Fig. 5) of a semiconductor device 10, and a second resin material 33 is used to apply a resin material to the rest of the board 20. Even if the distribution of the application of the first resin material 31 and the second resin material 33 to the board 20 is changed as described above, a resin leak 35 and the formation of a void 36 can be prevented. (Method for producing a power conversion device)(Fig. 8)

[0026] A method of producing the power conversion device 100A will be described with reference to Fig. 8(a) to Fig. 8(e). First, a method for producing the semiconductor device 10 and the plate 20 necessary for the power conversion device 100A will be described. Mounted components are described with reference to Fig. 5 and Fig. 6 without illustrating drawings to describe respective steps.

[0027] The semiconductor device 10 is first manufactured by bonding the power semiconductor element 11 to the heat spreader 12 with the bonding material (solder) 14, and electrically connecting a gate electrode of the power semiconductor element 11 to the external terminal 15 using a wire (not shown in the drawing). Next, the heat spreader 13 is bonded to a surface of the power semiconductor element 11 with the bonding material 14, the surface being opposite to the surface bonded to the heat spreader 12. Then, the power semiconductor element 11 and the heat spreaders 12 and 13 are sealed with the insulating resin 16 by transfer molding, while the heat spreaders 12 and 13 each have an exposed surface, the surface being opposite to the surface bonded to the power semiconductor element 11.Finally, the external terminal 15 is bent to complete the semiconductor device 10. The heat spreader 12 and the external terminal 15 are integrally formed using a lead frame.

[0028] Next, the multilayer printed circuit board 20 with four wiring layers is prepared. The power conversion device 100A handles a current of several hundred A, so a copper foil with a thickness of 200 μm (thicker than a copper foil generally used in an electronic device) is used for the wiring layer 22 of the board 20. The insulation layer 21 of the board 20 uses a glass fiber reinforced epoxy resin base material. The copper foil of each wiring layer 22 of the board 20 is etched in advance to serve as a circuit of the power conversion device 100. The board 20 is completed by forming the through-hole 24 as a location where the semiconductor device 10 is arranged and the through-hole 23 into which the external terminal 15 is inserted.

[0029] Based on the completion of the semiconductor device 10 and the board 20, a method for producing the power conversion device 100A will be described. Fig. Figure 8(a) illustrates the semiconductor device 10 arranged in the through-hole 24 of the plate 20 to arrange the heat spreader 12 on an insertion side (lower side). The external terminal 15 of the semiconductor device 10 is inserted into the through-hole 23 of the plate 20. Next, Fig. 8(b) illustrates the through-hole 23 and the external terminal 15, which are electrically connected to each other by pouring molten solder 30 into the through-hole using a reflow soldering device. Fig. 8(c) shows the semiconductor device 10 and the board 20 being turned over to fill a gap between the semiconductor device 10 and the board 20 with the first resin material 31 having a viscosity of 30 Pa*s at 25°C. The first resin material 31 is applied to cover the wiring layer 22 of the board 20 and cured under predetermined conditions. Here, a surface (first surface 12a) of the heat spreader 12 of the semiconductor device 10, the surface protruding toward the other surface of the board 20, is located outside the other surface of the board 20 to be prevented from being covered with the first resin material 31. As a result, the first resin material 31 or the second resin material 33 is not formed on the first surface 12a.

[0030] Next, Fig. 8(d) the semiconductor device 10 and the plate 20 which are reversed to be in the same state as in Fig. 8(b) to form the resin frame 32 with a non-flowable resin material in an end part of a surface of the plate 20, the surface not being coated with the resin material 31. Then, Fig. 8(e) shows the power conversion device 100A, which is completed by applying the second resin material 33 having a viscosity of 0.5 Pa*s at 25°C to a level covering the wiring layer 22 of the board 20 and curing the resin material 33 under predetermined curing conditions. When the first resin material 31 and the second resin material 33 contain fillers that differ from each other in content, a similar preparation process can be performed using the same resin material. At this time, the first resin material 31 needs to have a higher viscosity than the second resin material 33, so the first resin material 31 has a larger filler content than the second resin material 33. Examples of the filler include a powder component such as aluminum or silicon dioxide, and the viscosity increases as the content increases. (Method for manufacturing a power conversion device of a modification)(Fig. 9)

[0031] A method of producing the power conversion device 100B will be described with reference to Fig. 9(a) to Fig. 9(h). The power conversion device 100B is similar in the method for manufacturing the semiconductor device 10 and the plate 20 to that of the power conversion device 100A shown in Fig. 8 is described. Fig. 9(a) illustrates a surface around the through-hole 24 of the plate 20, the surface facing the flange portion 16a of the semiconductor device 10 and coated with the first resin material 31 having a viscosity of 100 Pa*s at 25°C. Next, Fig. 9(b) the semiconductor device 10 arranged in the through-hole 24 of the board 20 and the heat spreader 12 in its lower part located downward, the external terminal 15 of the semiconductor device 10 inserted into the through-hole 23 of the board 20, and the first resin material 31 cured under predetermined conditions to fix the semiconductor device 10 and the board 20 to each other and close a gap in the board 20 of the semiconductor device 10.

[0032] Next, Fig. 9(c) shows the through-hole 23 and the external terminal 15 which are electrically connected to each other by pouring molten solder 30 into the through-hole 23 using a reflow soldering device. Fig. Next, Fig. 9(d) illustrates the resin frame 32 made of a non-flowable resin material at an end part of a surface (surface provided with the first resin material 31 and in contact with the flange part 16a of the semiconductor device 10) of the board 20. Fig. Fig. 9(e) illustrates the second resin material 33 having a viscosity of 0.5 Pa*s at 25°C, which is applied to a height covering the wiring layer 22 of the board 20 and cured under predetermined curing conditions. Fig. 9(f) illustrates the semiconductor device 10 and the board 20 being reversed to form the resin frame 32 with a non-flowable resin material also in one end part of the other surface of the board 20. Fig. Fig. 8(g) illustrates the second resin material 33 having a viscosity of 0.5 Pa*s at 25°C, which is applied to a height covering the wiring layer 22 of the board 20 and cured under predetermined curing conditions. Fig. 9(h) illustrates the power conversion device 100B completed by reversing the semiconductor device 10 and the board 20 by 180 degrees after curing the resin material 33. (Fig. 10)

[0033] Results of a partial discharge test are described below, the partial discharge test being performed to verify the effect of insulation reliability of each of the power conversion device 100A according to the present invention, the power conversion device 100B of the modification, and the power conversion devices 100C and 100D, respectively, using a conventional technique.

[0034] The partial discharge test was conducted using a partial discharge measuring device that measures a voltage (partial discharge starting voltage) at which a partial discharge occurred in each sample when an AC voltage was applied between the external terminals 15 of the semiconductor device 10 and the AC voltage was gradually increased from 0 V. The external terminal 15 of the semiconductor device 10 was inserted into the through-hole 23 of the board 20 and connected by solder, so that the voltage was also applied to the wiring 22 of the board 20. A threshold value for determining that the partial discharge occurred was set to 10 pC, and a test voltage for the partial discharge was set to a maximum of 2.5 kVrms.

[0035] Fig. Figure 10(a) shows a test result of the power conversion device 100A. The test result shows that the second resin material 33 was filled into the upper part of the external terminal 15 of the semiconductor device 10 and the gap between the external terminal 15 and the plate 20 without forming the cavity 36, so no partial discharge occurred. Even at the maximum test voltage of 2.5 kVrms, no partial discharge occurred, and no dielectric breakdown occurred.

[0036] Fig. 10(b) shows a test result of the power conversion device 100B. The test result shows that the second resin material 33 was filled into the upper part of the external terminal 15 of the semiconductor device 10 and the gap between the external terminal 15 and the board 20 without forming the cavity 36, so no partial discharge occurred as in the power conversion device 100A. Even at the maximum test voltage of 2.5 kVrms, no partial discharge occurred, and no dielectric breakdown occurred.

[0037] Fig. 10(c) shows a test result of the power conversion device 100C. The test result shows that a discharge with a charge amount of 1000 pC or more was detected at a voltage exceeding an applied voltage of 1.7 kVrms. Dielectric breakdown (flashover) also occurred between the external terminals 15. This is considered to be because the resin material 34 leaks from the gap between the semiconductor device 10 and the board 20 to expose the external terminals 15, so that a creeping discharge occurs between the external terminals 15 to cause dielectric breakdown.

[0038] Fig.10(d) shows a test result of the power conversion device 100D. The test result shows that a partial discharge occurred at a voltage exceeding an applied voltage of 1.7 kVrms and exceeded the threshold value of 10 pC for partial discharge occurrence at 1.8 kVrms. After that, the voltage was increased to 2.0 kVrms, and the amount of discharged charge was about 40 pC. Even at the maximum test voltage of 2.5 kVrms, the amount of discharged charge was maintained at about 40 pC, and no dielectric breakdown occurred. This is considered because, although no dielectric breakdown occurred between the external terminals 15 due to the upper part of the external terminal 15 being covered with the resin material, the partial discharge occurred due to the cavity 36 formed under the external terminal 15.Although dielectric breakdown does not certainly occur in a short-term insulation test, it is conceivable that a high voltage applied for a long period of time in actual use may cause the resin material or the insulation layer 21 of the board 20 to undergo partial discharge deterioration, resulting in dielectric breakdown in the worst case.

[0039] As described above, the power conversion devices 100A and 100B of the present invention have excellent insulation reliability compared to the power conversion devices 100C and 100D each using a conventional technique. Thus, the present invention enables the insulation distance between the power conversion devices 100A and 100B to be further reduced, not only between the external terminals 15, but also between the wiring 22 of the board 20 and the wiring. This configuration can contribute to reducing the main circuit inductance and miniaturization. The power semiconductor element 11, which has a high withstand voltage, can be applied to the semiconductor device 10 and the power conversion devices 100A and 100B. (Fig. 11)

[0040] The power conversion device 100A of the present invention is provided with respective radiators 51 on its opposite surfaces, and an electrically insulating heat dissipation means 52 is provided between the power conversion device 100A and the radiator 51. This configuration enables the power conversion device 100A of the present invention to be mounted on a vehicle, such as an EV or an HEV.

[0041] An embodiment of the present invention described above achieves the following operational effects.

[0042] (1) The power conversion device 100A includes: the semiconductor device 10 including the semiconductor element 11 and the heat spreaders 12 and 13 sealed with the insulating resin 16, with the external terminal 15 protruding from the insulating resin 16; and the circuit board 20 equipped with the semiconductor device 10 and including the power wiring layer 22 connected to the external terminal 15. The circuit board 20 includes the through-hole 24, and the semiconductor device 10 includes: the external terminal 15 and the power wiring layer 22 connected to each other on one surface of the circuit board 20; and the heat spreader 12 and the insulating resin 16 arranged partially extending through a through-hole 24 to protrude to the other surface of the circuit board 20.The semiconductor device 10 includes the flange portion 16a facing or in contact with one surface of the circuit board 20 and covering the opening edge of the through-hole 24 in the one surface of the circuit board 20. The first resin material 31 is filled into at least one of the gap 41 between the inner peripheral surface of the through-hole 24 and the insulating resin 16 of the semiconductor device 10 in the through-hole 24, and the gap between the one surface of the circuit board 20 and the flange portion 16a. The one surface of the circuit board 20 is coated with a second resin material 33 to cover at least a connection portion between the external terminal 15 and the power wiring layer 22. This configuration makes it possible to provide the power conversion device 100A in which ensuring insulation reliability, improving heat dissipation, and miniaturization coexist.

[0043] (2) The second resin material 33 has higher fluidity in a molten state than the first resin material 31. This configuration prevents resin from leaking from the gap between the board 20 and the flange part 16a of the semiconductor device 10.

[0044] (3) The gap between the insulating resin 16 and the through-hole 24 increases along the direction in which the insulating resin 16 protrudes through the through-hole 24 to the other surface of the circuit board 20. This configuration prevents resin from leaking from the gap between the board 20 and the flange part 16a of the semiconductor device 10.

[0045] (4) The heat spreader 12 includes the first surface 12a protruding toward the other surface of the circuit board 20 and located outside the other surface of the circuit board 20, and the first surface 12a is provided without the first resin material 31 or the second resin material 33. This configuration prevents the resin material from forming on the heat spreader surface 12a.

[0046] (5) The first resin material 31 and the second resin material 33 each contain a filler, and the first resin material 31 has a larger filler content than the second resin material 33. Thus, even if the same resin material is used for the first resin material 31 and the second resin material 33, the viscosity can be separated by the filler content.

[0047] (6) The circuit board 20 includes the resin frame 32 at the end part of the surface coated with the second resin material 33, and the first resin material 31 and the second resin material 33 each have lower elasticity than a resin material used to form the resin frame 32 and the insulating resin 16 of the semiconductor device 10. As a result, a crack that is to be formed between the resin materials 31 and 33 and the board 20 or between the resin materials 31 and 33 and the insulating resin 16 of the semiconductor device can be suppressed.

[0048] The present invention is not limited to the above embodiments, and various modifications and other configurations can be combined without departing from the gist of the present invention. The present invention is also not limited to a configuration including each configuration described in each of the above embodiments, and includes a configuration in which part of the configuration is deleted. List of reference symbols 10 Power semiconductor device 11 Power semiconductor element 12 heat spreaders (collector side of the IGBT) 12a first surface 13 Heat spreader (emitter side of the IGBT) 14 Connecting material 15 external connection 16 insulating resin 16a flange part 20 circuit board 21 Insulation layer of the circuit board 22 circuit conductors (power wiring layer) of the printed circuit board 23 through hole 24 through-hole of the circuit board 30 connecting material (solder) 31 first resin material 32 resin frames 33 second resin material 34 Resin material (conventional) 35 Leak of resin material 36 unfilled part (cavity) of the resin 41 Gap between power semiconductor device and circuit board 41a Gap near the first surface 41b Gap near the plate 51 coolers 52 electrically insulating heat dissipation material 100 Power conversion device using a conventional technique 100A power conversion device of the present invention 100B Power conversion device of a modification 100C power conversion device with a first problem 100D power conversion device with a second problem QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 5898575 B2

[0006]

Claims

[1] Power conversion device comprising: a semiconductor device comprising a semiconductor element and a heat spreader sealed with an insulating resin, and an external terminal protruding from the insulating resin; and a circuit board equipped with the semiconductor device and including a power wiring layer connected to the external terminal, where the circuit board includes a through hole, the semiconductor device with the external terminal connected to the power wiring layer is arranged on one surface of the circuit board, while a part of the heat spreader and the insulating resin of the semiconductor device protrude through the through hole to another surface of the circuit board, the semiconductor device comprises a flange part facing or in contact with one surface of the circuit board and covering an opening edge of the through-hole on the one surface of the circuit board, at least one of a gap between an inner peripheral surface of the through-hole and the insulating resin of the semiconductor device in the through-hole and a gap between the one surface of the circuit board and the flange part is filled with a first resin material, and one surface of the circuit board is coated with a second resin material covering at least a connection part between the external terminal and the power wiring layer. [2] The power conversion device according to claim 1, wherein the second resin material has higher fluidity in a molten state than the first resin material. [3] The power conversion device according to claim 1, wherein a gap between the insulating resin and the through-hole increases along a direction in which the insulating resin protrudes through the through-hole to the other surface of the circuit board. [4] The power conversion device according to claim 1, wherein the heat spreader includes a first surface protruding toward the other surface of the circuit board and disposed outside the other surface of the circuit board, and the first surface is provided without the first resin material or the second resin material. [5] The power conversion device according to claim 1, wherein the first resin material and the second resin material each contain a filler, and the first resin material has a larger content of the filler than the second resin material. [6] Power conversion device according to one of claims 1 to 6, wherein the circuit board comprises a resin frame at an end part of the surface coated with the second resin material, and the first resin material and the second resin material each have lower elasticity than a resin material used to form the resin frame and the insulating resin of the semiconductor device.

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