Power semiconductor device, method for manufacturing a power semiconductor device and power converter device

Abstract

Power semiconductor device featuring the following: - one module unit (2); - an insulating resin element (12) connected to the module unit (2); - a cooling unit (13) connected to the module unit (2), with the insulating resin element (12) arranged between them; and - a flow barrier (11) arranged between the module unit (2) and the cooling unit (13) to surround the insulating resin element (12), wherein the flow barrier (11) is more compressibly deformable than the insulating resin element (12); wherein the flow barrier (11) is made of aluminium, indium, tin, an aluminium alloy, an indium alloy, a tin alloy or rubber.

Description

TECHNICAL FIELD

[0001] The present invention relates to a power semiconductor device comprising a power module in which a power semiconductor element is sealed, and a heat dissipation member having a heat-conductive resin insulating layer disposed between the power module and the heat dissipation member, a method for manufacturing a power semiconductor device, and a power conversion device. STATE OF THE ART

[0002] Heat dissipation is one of the critical challenges for power modules. One of the solutions that has been proven in practice is power semiconductor devices, in which a thermally conductive resin insulating layer, which serves as an adhesion promoter, electrical insulator, and heat conductor, is sandwiched between a heat sink, which is a heat dissipation element, and a power module. Examples of a thermally conductive resin insulating layer include a thermosetting resin layer containing an inorganic filler, an inorganic molded body layer impregnated with a thermosetting resin, a coating, and the like. Applying heat and pressure to such a thermally conductive resin insulating layer causes the thermally conductive resin insulating layer to act as an adhesion promoter to bond the power module and the heat sink together.

[0003] Under the influence of heat, the thermally conductive resin insulating layer softens before the resin hardens, and then the resin flows under pressure to reduce the originally existing voids and thus achieve the desired electrical insulation. However, the application of pressure causes a force to act on the end of the thermally conductive resin insulating layer, causing resin to leak from the end, that is, resin leakage occurs. At this time, the resin flows around the end of the thermally conductive resin insulating layer, the resin is no longer sufficient to fill the voids, and as a result, the voids are not sufficiently reduced, or a plurality of voids are combined to form a larger void, which may not achieve the desired electrical insulation.

[0004] Therefore, to solve this problem, a thickness limiting member for a thermally conductive resin insulating layer is used to limit the thickness of the thermally conductive resin insulating layer, thereby restricting the amount of resin leaking from the thermally conductive resin insulating layer when pressure is applied (e.g., Patent Document 1).

[0005] Patent Document 2 relates to a semiconductor device for solving the problem that the insulating resin layer between the power module (semiconductor module) and the heat sink is not sufficiently pressurized.

[0006] Patent Document 3 relates to a power semiconductor module for improving the insulation properties and heat dissipation properties of a resin-sealed power semiconductor module having a higher withstand voltage. STATE OF THE ART Patent document 1: JP 2012 - 174 965 A Patent document 2: DE 11 2019 007 574 T5 Patent document 3: WO 2016 / 076 015 A1 SUMMARY OF THE INVENTION Problems to be solved by the invention

[0007] In the power semiconductor device described in Patent Document 1, a thickness-limiting member is provided for the thermally conductive insulating resin plate to make the thickness of the thermally conductive insulating resin plate equal to a desired thickness when pressure is applied. However, it is not possible to prevent resin from flowing out of the thermally conductive insulating resin plate when pressure is applied, and voids are generated around the end of the thermally conductive insulating resin plate, so that the electrical insulation is not high enough, and the reliability of the power semiconductor device may deteriorate accordingly. The present invention provides a power semiconductor device in which the resin is prevented from flowing out of a thermally conductive insulating resin plate when pressure is applied, and which has electrical insulation to achieve higher reliability. Means to solve the problems

[0008] A power semiconductor device according to the present invention includes a module unit, an insulating resin element connected to the module unit, a cooling unit coupled to the module unit with the insulating resin element arranged therebetween, and a flow barrier arranged between the module unit and the cooling unit and surrounding the insulating resin element, the flow barrier being more easily deformable under pressure than the insulating resin element, the flow barrier (11) being made of aluminum, indium, tin, an aluminum alloy, an indium alloy, a tin alloy or rubber. Effect of the invention

[0009] According to the present invention, a flow barrier is provided around the insulating resin member, so that it is possible to suppress the formation of voids around the end of the insulating resin member and increase the reliability of the power semiconductor device. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a plan view schematically showing a power semiconductor device according to a first embodiment of the present invention; Fig. 2 is a sectional view schematically illustrating the power semiconductor device according to the first embodiment of the present invention; Fig. 3 is a sectional view schematically showing the power semiconductor device according to the first embodiment of the present invention in a state where pressure has not yet been applied; Fig. 4 is a sectional view schematically showing the power semiconductor device according to the first embodiment of the present invention in a state where pressure has already been applied; Fig. 5 is a sectional view schematically illustrating the power semiconductor device according to the first embodiment of the present invention having another type of flow barrier in a state where pressure has not yet been applied; Fig. 6 is a sectional view schematically showing the power semiconductor device according to the first embodiment of the present invention including the other type of flow barrier in a state where pressure has been applied; Fig. 7 is an external structural view schematically illustrating one side of the power semiconductor device according to the first embodiment of the present invention; Fig. 8 is a plan view schematically illustrating the power semiconductor device according to the first embodiment of the present invention; Fig. 9 is an external structural view schematically illustrating one side of another type of the power semiconductor device according to the first embodiment of the present invention; Fig. 10 is a plan view schematically illustrating the different type of power semiconductor device according to the first embodiment of the present invention; Fig. 11 is a sectional view schematically illustrating a power semiconductor device according to a comparative example; Fig. 12 is a plan view schematically illustrating the power semiconductor device according to the comparative example; Fig. 13 is a plan view schematically illustrating a flow barrier according to the first embodiment of the present invention; Fig. 14 is a plan view schematically illustrating another type of flow barrier according to the first embodiment of the present invention; Fig. 15 is a plan view schematically illustrating another type of flow barrier according to the first embodiment of the present invention; Fig. 16 is a plan view schematically illustrating another type of flow barrier according to the first embodiment of the present invention; Fig. 17 is a plan view schematically illustrating another type of flow barrier according to the first embodiment of the present invention; Fig. 18 is a plan view schematically illustrating a manufacturing step of the power semiconductor device according to the first embodiment of the present invention; Fig. 19 is a plan view schematically illustrating the manufacturing step of the power semiconductor device according to the first embodiment of the present invention; Fig. 20 is a plan view schematically illustrating the manufacturing step of the power semiconductor device according to the first embodiment of the present invention; Fig. 21 is a plan view schematically illustrating a manufacturing step of another type of the power semiconductor device according to the first embodiment of the present invention; Fig. 22 is a plan view schematically illustrating the manufacturing step of the other type of power semiconductor device according to the first embodiment of the present invention; Fig. 23 is a plan view schematically illustrating the manufacturing step of the different type of power semiconductor device according to the first embodiment of the present invention; Fig. 24 is a sectional view schematically illustrating a power semiconductor device according to a second embodiment of the present invention; Fig. 25 is a sectional view schematically illustrating another type of the power semiconductor device according to the second embodiment of the present invention; Fig. 26 is a sectional view schematically illustrating a power semiconductor device according to a third embodiment of the present invention; Fig. 27 is a sectional view schematically illustrating a manufacturing step of the power semiconductor device according to the third embodiment of the present invention; Fig. 28 is a sectional view schematically illustrating the manufacturing step of the power semiconductor device according to the third embodiment of the present invention; Fig. 29 is a sectional view schematically illustrating another type of the power semiconductor device according to the third embodiment of the present invention; Fig. 30 is a sectional view schematically illustrating another type of the power semiconductor device according to the third embodiment of the present invention, and Fig. 31 is a block diagram illustrating the structure of a power conversion system in which a power conversion apparatus according to a fourth embodiment of the present invention is employed. DESCRIPTION OF THE EMBODIMENTS

[0010] First, an overall structure of a power semiconductor device according to the present invention will be described with reference to the drawings. Note that the drawings are schematic representations and do not show the actual sizes of the components. Furthermore, the components designated by the same reference numerals are identical or equivalent, and this applies throughout the description. Embodiment 1

[0011] Fig. 1 is a plan view schematically showing a power semiconductor device according to the first embodiment of the present invention. Fig. 2 is a sectional view schematically illustrating the power semiconductor device according to the first embodiment of the present invention. Fig. 1 is a plan view schematically showing a power semiconductor device 100 in plan view through a sealing element 5. Fig. 2 is a schematic sectional view along the dot-dash line AA in Fig. 1.

[0012] In the drawings, the power semiconductor device 100 includes a module unit 2, a cooling unit 13, an insulating resin member 12, and a flow barrier 11. The module unit 2 further includes a power semiconductor element 3, an electrically conductive member 4 having a plate shape, input / output terminals 6a, 6b, an adhesive 7, 8a, 8b, and a sealing member 5. The cooling unit 13 further includes a heat sink 10, fins 15, and a water jacket 14.

[0013] In the drawings, in the power semiconductor device 100, the module unit 2 and the cooling unit 13 are coupled with the insulating resin element 12 arranged therebetween. The flow prevention element, i.e., the flow barrier 11, is arranged around the insulating resin element 12 so that it surrounds the insulating resin element 12 and is located between the module unit 2 and the cooling unit 13.

[0014] In Fig. In Figure 1, the sealing element 5 is represented by a dashed line to show the positional relationship between the elements sealed in the sealing element 5. The outermost periphery of the power semiconductor device 100 coincides with the edge of the cooling unit 13. The sealing element 5 (module unit 2) is arranged inside the edge of the cooling unit 13. Furthermore, the flow barrier 11 is arranged inside the periphery of the sealing element 5 and outside the periphery of the insulating resin member 12.

[0015] Furthermore, the insulating resin member 12 is larger in outline than the electrically conductive member 4, and the electrically conductive member 4 is arranged within the periphery of the insulating resin member 12. The power semiconductor element 3 and the input / output terminal 6b are arranged on top of the electrically conductive member 4. The input / output terminal 6a is arranged on an upper electrode provided on the upper surface of the power semiconductor element 3.

[0016] In Fig. 2, a lower electrode (not shown) provided on the lower surface of the power semiconductor element 3 is electrically connected to the upper surface of the electrically conductive member 4, which has a plate shape, via an adhesive 7. Further, the input / output terminal 6b is electrically connected to the upper surface of the electrically conductive member 4, which has a plate shape, via the adhesive 8b. Further, the upper electrode (not shown) provided on the upper surface of the power semiconductor element 3 is electrically connected to the input / output terminal 6a via the adhesive 8a.

[0017] In the sealing member 5, the power semiconductor element 3, the electrically conductive member 4, and the input / output terminals 6a, 6b are sealed with a heat dissipation surface, which is the lower surface of the electrically conductive member 4 having an exposed plate shape, with one end of each of the input / output terminals 6a, 6b protruding from the sealing member 5 and the other end disposed within the sealing member 5. The lower surface of the electrically conductive member 4 protruding from the sealing member 5 is arranged on (coupled to) the upper surface of the cooling unit 13 (the upper surface of the heat sink 10), with the insulating resin member 12 interposed between the lower surface and the upper surface.

[0018] The flow barrier 11 and the insulating resin element 12 satisfy the relationship E seal < E seat , where E seal represents the resistance to compression of the flow barrier 11 and E seatrepresents the resistance to compression of the insulating resin element 12. In other words, the resistance to compression of the flow barrier 11 is smaller than the resistance to compression of the insulating resin element 12. Here, the resistance E to compression is given by E = σ c / ε, where σ c represents the compressive stress and ε represents the compressive strain. Such compressive deformation includes elastic deformation, plastic deformation, rubber elasticity, or a combination thereof.

[0019] Next, the structure, material and material properties of the individual components are described.

[0020] First, the components that make up module unit 2 are described.

[0021] The power semiconductor element 3 has a top surface and a bottom surface. The power semiconductor element 3 has the upper electrode provided on the upper surface and the lower electrode provided on the lower surface. The input / output terminal 6a is connected to the upper electrode of the power semiconductor element 3 via the adhesive 8a. Examples of the device structure of the power semiconductor element 3 include an insulated gate bipolar transistor (IGBT), a metal oxide semiconductor field-effect transistor (MOSFET), a bipolar transistor, and a diode, and examples of the substrate material include wide band-gap semiconductors such as silicon (Si), silicon carbide (SiC), gallium nitride (GaN), and gallium oxide (GaO).

[0022] The electrically conductive element 4 is a plate-shaped element. The electrically conductive element 4 has an upper surface and a lower surface. The power semiconductor element 3 and the input / output terminal 6b are bonded to the upper surface of the electrically conductive element 4 by adhesives 7, 8b. The electrically conductive element 4 is made of a material with excellent electrical and thermal conductivity, such as copper (Cu), aluminum (Al), an alloy composed mainly of copper or aluminum, or a carbon-based material such as carbon nanotubes or graphite. Furthermore, the surface of the electrically conductive element 4 may be subjected to a surface treatment such as Ni-P plating.

[0023] In the sealing member 5, the power semiconductor element 3, the electrically conductive member 4, and the input / output terminals 6a, 6b are sealed to the heat dissipation surface, which is the lower surface of the electrically conductive member 4, which has an exposed plate shape, with one end of each of the input / output terminals 6a, 6b exposed from one side of the sealing member 5 and the other end disposed inside the sealing member 5. The sealing member 5 is formed by injection molding an epoxy resin containing a filler such as silicon dioxide.

[0024] The input / output terminals 6a, 6b electrically couple the inside and outside of the module unit 2. The input / output terminals 6a, 6b are made of a highly conductive material such as copper. Two or more input / output terminals 6a, 6b can be provided in a manner that depends on the circuit structure of the module unit 2.

[0025] The power semiconductor element 3 and the electrically conductive element 4 are connected to each other by an adhesion promoter 7. The adhesion promoter 7 is also referred to as a die adhesion promoter, die attach agent, or under-chip adhesion promoter, and it is important that the adhesion promoter 7 exhibits excellent electrical conductivity and thermal conductivity as well as high mechanical reliability against thermal stress and shock.

[0026] Sn-based solder is commonly used as the material for the adhesion promoter 7, but in recent years, sintered Ag or sintered Cu using nanoparticles, transient liquid phase diffusion (TLP), and the like have also been used. The material of the adhesion promoter 7 can be appropriately selected from the perspective of balancing performance and cost. Furthermore, the connection between the power semiconductor element 3 and the electrically conductive element 4 having a plate shape can be, for example, a direct connection between the power semiconductor element 3 and the electrically conductive element 4 having a plate shape without explicitly using the adhesion promoter 7.

[0027] The input / output terminals 6a, 6b and the power semiconductor element 3 or the electrically conductive element 4 are connected to each other by the bonding agent 8a, 8b. The bonding agent 8a, 8b has a lower thermal conductivity than the bonding agent 7, but can have the same composition as the bonding agent 7. Furthermore, direct bonding, such as ultrasonic bonding or welding without explicit bonding agent 8a, 8b, can be applied to the areas bonded with the bonding agent 8a, 8b.

[0028] In the above description, direct lead bonding (DLB) is applied to the main wire bonding of the module unit 2, but bonding with a commonly used aluminum (Al) or copper (Cu) wire, or other bonding methods may be used. Furthermore, the module unit 2 is not limited to a transfer molding (injection molding) type unit and only needs to be capable of applying heat and pressure to the insulating resin member 12.

[0029] Next, the components that make up the cooling unit 13 are described.

[0030] The cooling unit 13 includes the heat sink 10 and the water jacket 14. The upper surface of the heat sink 10 is flush with the upper surface of the cooling unit 13. The heat sink 10 and fins 15 are typically made of copper or aluminum with excellent thermal conductivity, or of an alloy consisting primarily of copper or aluminum. Furthermore, the heat sink 10 and fins 15 can be made of a carbon-based material such as carbon nanotubes or graphite, which has very high thermal conductivity and is lightweight, or of another material with excellent thermal conductivity.

[0031] Furthermore, the surfaces of heat sink 10 and fins 15 can be coated to increase corrosion resistance or facilitate bonding. The heat sink 10 and fins 15 can be manufactured by machining or, alternatively, by casting or molding with a die.

[0032] The water jacket 14 is combined with the heat sink 10 to form the cooling unit 13. The combination of the water jacket 14 and the heat sink 10 forms a channel with fins 15 therein. The water jacket 14 is typically die-cast from aluminum, which is lightweight and easy to cast, but can also be made from other materials.

[0033] The structure in which the heat sink 10, which is commonly used in power semiconductor devices in vehicles, for example, serves as the portion of the cooling unit 13 has been described above, but the cooling method is not limited to water cooling. Furthermore, the heat sink 10 and fins 15 may have not only a structure in which the heat sink 10 and fins 15 are integrally formed, but also a structure and material suitable for their use as the cooling unit 13.

[0034] Next, the insulating resin member 12 and the flow barrier 11 serving as the core of the present invention will be described.

[0035] The insulating resin element 12 connects the lower surface of the module unit 2 and the upper surface of the cooling unit 13. The insulating resin element 12 is designed to be larger in outline than the electrically conductive element 4 of the module unit 2. As a result, the upper surface of the insulating resin element 12 comes into contact with the lower surface of the electrically conductive element 4 and the lower surface of the sealing element 5. The insulating resin element 12 not only provides excellent thermal conductivity and electrical insulation, but also serves as an adhesive (adhesion promoter) between the module unit 2 and the cooling unit 13 and is mechanically very reliable against thermal stress and impact.

[0036] As a material for the insulating resin member 12 that meets such a requirement, a thermally conductive layer in which an inorganic filler is dispersed in a cured thermosetting resin is often used. Examples of the inorganic filler are boron nitride, silicon nitride, alumina, and the like. Examples of the thermosetting resin are epoxy resin, polyimide resin, polyamide resin, and the like. Boron nitride, as an inorganic filler, possesses excellent chemical stability in addition to thermal conductivity and electrical insulation. It is non-toxic and relatively inexpensive, and is therefore widely used for applications requiring particularly high thermal conductivity and high insulation.

[0037] Furthermore, an insulating resin member is also available that is superior to a conventional thermally conductive plate. The insulating resin member is formed by forming a base that is isotropically aligned by applying pressure and sintering a highly thermally conductive inorganic material, such as boron nitride, which is prepared in advance in particulate form and has a large contact area between highly thermally conductive inorganic materials. Then, gaps in the highly thermally conductive inorganic material are impregnated with a thermosetting resin. Furthermore, the height (thickness) of the insulating resin member 12 is, for example, in a range of about 0.2 mm to 0.4 mm.

[0038] The flow barrier 11 is arranged around the insulating resin element 12 and surrounds the insulating resin element 12. The flow barrier 11 is arranged within the periphery of the modular unit 2 or sealing element 5. The upper surface of the flow barrier 11 is in contact with the lower surface of the sealing element 5. The flow barrier 11 is more easily compressively deformed than the insulating resin element 12. The flow barrier 11 serves as a wall that resists a force that causes the resin in the insulating resin element 12, to which heat and pressure are applied at the time of joining the modular unit 2 and the cooling unit 13, to leak or flow out from the end or periphery of the insulating resin element 12 toward the periphery of the modular unit 2. In other words, the flow barrier 11 serves as a sealant for the insulating resin element 12.

[0039] The thermosetting resin can assume an extremely low viscosity when heated. When the module unit 2 and the cooling unit 13 are connected by the insulating resin member 12, the maximum pressure at which the resin is forced to leak or flow out of the end of the insulating resin member 12 is a hydrostatic pressure, which is almost the same pressure as the pressing condition for the upper surface of the module unit 2. The actual pressure value when the module unit 2 and the cooling unit 13 are connected depends on the material of the insulating resin member 12, but can reach, for example, 10 MPa, and the leakage pressure on the resin can become extremely large, on the order of several MPa.

[0040] In order to seal the resin against the pressure with this value, it is a matter of course that there is no gap at the top and bottom of the flow barrier 11 (an interface with the module unit 2 or the heat sink 10), but in order to prevent the resin from leaking from the top and bottom positions of the flow barrier 11, it is necessary to induce a state in which sufficient pressure is exerted on the flow barrier 11 from the module unit 2 and the heat sink 10 between which the flow barrier 11 is arranged.

[0041] Fig. 3 is a sectional view schematically showing the power semiconductor device according to the first embodiment of the present invention in a state where pressure has not yet been applied. Fig. 4 is a sectional view schematically showing the power semiconductor device according to the first embodiment of the present invention in a state where pressure has been applied. Fig. 3 illustrates a state in which the module unit 2 and the heat sink 10 are not yet glued together. Fig. 4 shows a state in which the module unit 2 and the heat sink 10 are glued together.

[0042] In the drawings, a flow barrier 11b is a resin flow barrier in a state in which no pressure has been applied to the module unit 2 and the heat sink 10 (the module unit 2 and the heat sink 10 have yet to be bonded together). Furthermore, the insulating resin member 12b is an insulating resin member in a state in which no pressure has been applied to the module unit 2 and the heat sink 10 (the module unit 2 and the heat sink 10 have yet to be bonded together). As shown in Fig. 3, the flow barrier 11b is arranged at a distance from the periphery or edge of the insulating resin element 12b in the state in which the pressure has not yet been applied.

[0043] At this time, the flow barrier 11b is higher or thicker than the insulating resin element 12. As in Fig. As shown in Figure 4, the application of pressure causes the flow barrier 11b to compress, preventing the insulating resin member 12b from flowing out toward the periphery of the module unit 2 and preventing resin flow or leakage. At this time, the flow barrier 11 is compressed upon application of pressure so that it has the same height as the insulating resin member 12. This makes it possible to prevent resin leakage from the insulating resin member 12.

[0044] In order to apply sufficient pressure to the flow barrier 11 while simultaneously applying sufficient pressure to the insulating resin member 12 in a heat and pressure application step at the time of joining the module unit 2 and the heat sink 10, it is important that the flow barrier 11 is made of a material that has a greater height than the insulating resin member 12 in a state where no pressure is applied (the connection has yet to be made), and that it easily deforms in response to the compressive stress applied when the module unit 2 and the heat sink 10 are bonded together, and that a sharp reduction in the pressure applied to the insulating resin member 12 is avoided.

[0045] This means that the height of the flow barrier 11b in a state in which the bonding has not yet taken place is given by t 11bthe height of the insulating resin element 12b in a state in which the bonding has not yet taken place is denoted by t 12b the height of the insulating resin element 12 in a state in which the bonding has taken place is denoted by t 12 denoted if t 11b > t 12b > t 12 and the resistance to compression of the flow barrier 11 with E seal and the resistance to compression of the insulating resin element 12 with E seat is called, a relationship E seal < E seat In other words, the height of the flow barrier 11b in a state where bonding has not yet occurred is greater than the height of the insulating resin member 12b in a state where bonding has not yet occurred, and the resistance of the flow barrier 11 to compression is smaller than that of the insulating resin member 12.

[0046] Furthermore, the flow barrier 11 must have heat resistance to the heating temperature when the module unit 2 and the heat sink 10 are bonded together. Typically, the bonding temperature is between 180 and 250°C, and therefore, the flow barrier 11 must have heat resistance of at least 200°C, preferably 250°C or higher.

[0047] Examples of the material of the flow barrier 11 include a rubber material such as a fluorine- or silicone-based rubber material, a low-compression-strength material characterized by a low-hardness metal such as aluminum, indium, or tin, and an aluminum, indium, or tin alloy mainly composed of aluminum, indium, or tin. Furthermore, the height or thickness of the flow barrier 11 can be appropriately selected depending on the material of the flow barrier 11, and can be formed, for example, to be 1.05 to 2 times the height of the insulating resin member 12. Furthermore, the width of the flow barrier 11 can be suitably selected in a range of about 1 / 2 to 2 in terms of the aspect ratio to the thickness of the flow barrier 11.

[0048] It should be noted that the cross-sectional shape of the flow barrier 11 in a state where the module unit 2 and the heat sink 10 are not yet connected to each other can have various shapes, such as a circle, an ellipse, a triangle and a hexagon, in addition to the shape shown in Fig. 3 shown quadrilateral.

[0049] Fig. 5 is a sectional view schematically showing the power semiconductor device according to the first embodiment of the present invention having another type of flow barrier in a state where pressure has not yet been applied. Fig. 6 is a sectional view schematically showing the power semiconductor device according to the first embodiment of the present invention including the other type of flow barrier in a state where the pressure has been applied. Fig. 5 shows a state in which the module unit 2 and the heat sink 10 are not yet glued together, and Fig. 6 shows a state in which the module unit 2 and the heat sink 10 are glued together.

[0050] In Fig. 5, the flow barrier 11 is circular in cross-section. The flow barrier 11 is preferably square or circular in shape for ease of molding. As shown in Fig. 5, the flow barrier 11b, even if it is circular, is arranged at a distance from the insulating resin member 12 in a state in which no pressure has been applied. At this time, the flow barrier 11b has a greater height than the insulating resin member 12. As shown in Fig. As shown in Figure 6, the application of pressure causes the flow barrier 11b to compress, preventing the insulating resin member 12 from flowing out toward the periphery of the module unit 2 and preventing resin flow. At this time, the flow barrier 11 is compressed under pressure so that it has the same height as the insulating resin member 12.

[0051] The planar shape or top view of the flow barrier 11 is described below.

[0052] Fig. 7 is an external structural view schematically showing one side of the power semiconductor device according to the first embodiment of the present invention. Fig. 8 is a plan view schematically illustrating the power semiconductor device according to the first embodiment of the present invention. Fig. Figure 8 is a schematic plan view along a dot-dash line BB in Fig. 7.

[0053] As shown in the drawings, in the state where the module unit 2 and the heat sink 10 are not yet bonded together, the flow barrier 11b is arranged around the insulating resin member 12b or with a gap. When the flow barrier 11b is arranged as described above, resin can be prevented from flowing out of the insulating resin member 12 over the entire circumference when heat and pressure are applied to bond the module unit 2 and the heat sink 10. For the purpose of sealing to prevent resin flow, it is desirable that the flow barrier 11b arranged around the insulating resin member 12b be free of a joint that is prone to mechanical weakness.

[0054] The frame shape without a joint of the flow barrier 11b can be produced by stamping from a plate-like material. For the production of the flow barrier 11b, it is desirable that the flow barrier 11b be formed with a die or cast from a mold in terms of yield.

[0055] A method for positioning the resin flow barrier 11 is described below.

[0056] Fig. 9 is an external structural view schematically showing one side of another type of power semiconductor device according to the first embodiment of the present invention. Fig. 10 is a plan view schematically illustrating the other type of power semiconductor device according to the first embodiment of the present invention. Fig. 10 is a schematic sectional view taken along the dot-dash line CC in Fig. 9.

[0057] Fig. 9 and Fig. 10 illustrates an example of the method for positioning the module unit 2 and the flow barrier 11. In the drawings, a positioning pin 32 of the module unit 2 is injection-molded so as to protrude from the periphery of the module unit 2 when the module unit 2 is sealed in the sealing member 5. A positioning hole is formed in the top surface of the heat sink 10 at a position corresponding to the positioning pin 32 of the module unit 2, and the positioning pin 32 of the module unit 2 is inserted into the positioning hole to position the module unit 2 on the heat sink 10. The flow barrier 11 also has a through-hole formed at a position corresponding to the positioning pin 32 of the module unit 2 in a positioning projection 31 of the flow barrier 11, which protrudes toward the periphery of the heat sink 10, to be positioned relative to the module unit 2.

[0058] In the above description, the positioning pin 32 of the module unit 2 is arranged on the side of the module unit 2, but a positioning pin or positioning frame for positioning relative to the module unit 2 may also be arranged on the side of the heat sink 10. In particular, when the heat sink 10 is molded with a die or cast from a mold, the positioning pin or positioning frame can be easily molded.

[0059] Furthermore, as another positioning method, the flow barrier 11 and the insulating resin member 12 can be formed in advance as one piece by pressing the insulating resin member 12 into the flow barrier 11 or by temporarily bonding the insulating resin member 12 and the flow barrier 11 together. The insulating resin member 12 is suitable, for example, for a material with a certain mechanical strength, such as a resin-impregnated boron nitride base.

[0060] As described above, a flow barrier 11 is arranged around the insulating resin member 12, which is more easily compressively deformable than the insulating resin member 12, so that even when pressure is applied to the module unit 2 and the cooling unit 13 to bond the module unit 2 and the cooling unit 13, the formation of voids in the periphery of the insulating resin member 12 is suppressed. This enables an increase in the insulation and heat dissipation of the bond between the module unit 2 and the cooling unit 13 and increases the reliability of the power semiconductor device 100.

[0061] Next, a manufacturing method for the power semiconductor device 100 according to the first embodiment constructed as described above will be described.

[0062] First, the module unit 2 of the power semiconductor component 100 is manufactured. The lower electrode of the power semiconductor component 3 is bonded to the upper surface of the electrically conductive element 4 via the bonding agent 7. The input / output terminal 6a is connected to the upper electrode of the power semiconductor element 3 via the bonding agent 8a. The input / output terminal 6b is bonded to a predetermined location on the upper surface of the electrically conductive element 4 via the bonding agent 8b.

[0063] After the power semiconductor element 3 and the input / output terminals 6a, 6b are connected to the top surface of the electrically conductive element 4, the power semiconductor element 3 and the input / output terminals 6a, 6b are molded into the sealing member 5 with the bottom surface of the electrically conductive element 4 exposed, thereby forming the module unit 2 (module unit forming step).

[0064] Next, the bottom of the heat sink 10 and the water jacket 14 are bonded together to surround the heat sink 10 and the fins 15 arranged on the bottom of the heat sink 10, thereby forming the cooling unit 13 (cooling unit manufacturing step).

[0065] Next, the insulating resin member 12 (12b) is placed on the upper surface of the cooling unit 13 (heat sink 10) (insulating resin member placement step). After the insulating resin member 12 is placed, the flow barrier 11 (11b) is placed around the insulating resin member 12 so that it is separated from the edge of the insulating resin member 12 (insulating resin and flow barrier placement step).

[0066] The module unit 2 is arranged on the top side of the cooling unit 13 so that the top side of the thus arranged insulating resin member 12 is brought into contact with the bottom side of the electrically conductive member 4 of the module unit 2 (module unit arrangement step).

[0067] After the modular unit 2 is placed on top of the cooling unit 13, heat and pressure are applied to the modular unit 2 and the cooling unit 13 to bond the modular unit 2 and the cooling unit 13 together (modular unit bonding step). At this time, since the flow barrier 11 has lower resistance to compression deformation (is more easily deformed under pressure) than the insulating resin member 12, applying pressure to the side of the modular unit 2 causes the flow barrier 11b to be compressed, thereby preventing the insulating resin member 12b from leaking out of the periphery of the modular unit 2.

[0068] The Fig. 1 and Fig. The power semiconductor device 100 shown in Figure 2 can be manufactured by the essential manufacturing steps described above.

[0069] As a result of intensive studies on the planar shape of the flow barrier 11, it was found that the electrical insulation between the module unit 2 and the heat sink 10 (cooling unit 13) can be ensured even if a gap is provided in a region of the flow barrier 11 arranged in the peripheral region of the insulating resin member 12.

[0070] Fig. 11 is a sectional view schematically showing a power semiconductor device according to a comparative example. Fig. 12 is a plan view schematically illustrating the power semiconductor device according to the comparative example. Fig. 11 is a schematic sectional view taken along a dot-dash line DD in Fig. 12. In Fig. 12, the input / output terminals 6a, 6b are shown by dashed lines to illustrate a state of the resin 41 flowing out of the insulating resin member 12.

[0071] As in the Fig. 11 and Fig. As shown in Fig. 12, resin 41 flows out of the insulating resin member 12 when the flow barrier 11 is not provided, and the amount of resin 41 flowing out of the insulating resin member 12 is larger at the center of each of the four sides of the insulating resin member 12 and is almost zero at the corners of each side. That is, in a state where the module unit 2 and the cooling unit 13 are not yet bonded to each other, the resin at the corners of each side of the insulating resin member 12 is attracted to the center of the side by bonding (applying pressure to the module unit 2 and the cooling unit 13), resulting in a shortage of resin at the corners of each side. This makes the power semiconductor device vulnerable to dielectric breakdown at the corners of each side of the insulating resin member 12.

[0072] That is, it was found that arranging the joint of the flow barrier 11 around a corner of one side of the insulating resin member 12 prevents the resin shortage at the corner of the side of the insulating resin member even if resin flows from the joint of the flow barrier 11, thereby achieving good dielectric strength.

[0073] A modification of the planar shape (in plan view) of the flow barrier 11 is described below on the basis of the above findings.

[0074] Fig. 13 to 17 are plan views schematically illustrating flow barriers according to the first embodiment of the present invention.

[0075] The drawings also show the insulating resin element 12b together with the flow barrier 11b. Fig. 13 shows the flow barrier 11b without joint, similar to the one in Fig. 8 shown structure. In Fig. 13, the seamless flow barrier 11b is arranged around the insulating resin element 12b. In the Fig. 14 to 16 show structural examples in which the flow barrier 11b has a joint in a corner region of one side of the insulating resin element 12b.

[0076] Fig. 14 shows a structure in which the joint of the flow barrier 11b is in contact (bonded) with the corner of the side of the insulating resin member 12b. Fig. 15 shows a structure in which the flow barrier 11 overlaps at the joint of the flow barrier 11b. Fig. Figure 16 illustrates a structure in which the flow barrier 11b intersects at the corner of the side of the insulating resin member 12b and the joint extends approximately along a plane. Furthermore, Fig. 17 shows an example in which a plurality of flow barriers 11b are used and a plurality of joints are provided, in particular, the joints of the flow barriers 11b are provided at four corners of the sides.

[0077] The joint of each flow barrier 11b can be similar to that in Fig. 15 or Fig. 16. If a single joint of the flow barrier 11b, as shown in the Fig. 14 to 16, the flow barrier 11b may be formed from a wire rod, and if a plurality of joints are provided at the corners of each side of the flow barrier 11, as shown in Fig. 17, the flow barrier 11b may be formed from a plurality of wire rods. As described above, the flow barrier 11b is made of a wire rod, and the crossing or connecting portion of the flow barrier 11b, which is arranged around the insulating resin member 12b, is located at a corner of the insulating resin member 12b.

[0078] Next, a modification of the above-described method for positioning the flow barrier 11 including the flow barrier 11 will be described.

[0079] As described above, when a wire rod is used as the flow barrier 11, forming a positioning notch 33, 34 for positioning the flow barrier 11 on at least one of the module unit 2 and the heat sink 10 and inserting the wire rod into the positioning notch 33, 34 for positioning the flow barrier 11 is easier than forming the positioning projection 31 of the flow barrier 11 as shown in FIGS. Fig. 9 and Fig. 10 shown.

[0080] Fig. 18 to 23 are plan views schematically showing a manufacturing step of the power semiconductor device according to the first embodiment of the present invention. Fig. 18 to 20 illustrate a case in which the positioning notch 33 for positioning the flow barrier 11 is formed on the top side of the heat sink 10. The Fig. 21 to 23 show a case in which the positioning notch 34 for positioning the flow barrier 11 is formed on the bottom of the module unit 2.

[0081] The flow barrier 11b in a state in which the module unit 2 and the cooling unit 13 are not yet glued together is in the Fig. 18 to 20, the cross-section is circular. Fig. In the case illustrated in Figures 21 to 23, the flow barrier 11b has a square cross-section. In any case, regardless of the location of the positioning notch 33, 34 for positioning the flow barrier 11, the flow barrier 11 may be circular, square, or have another shape in cross-section.

[0082] In a case where the positioning notch 33 is formed on the top side of the heat sink 10, as shown in Fig. 18, the positioning notch 33 is provided on the top side of the heat sink 10 by machining, such as cutting, preferably by casting or molding with a mold. Next, as shown in Fig. 19, the flow barrier 11b is arranged in a state in which the bonding has not yet taken place so that it fits into the positioning notch 33.

[0083] Then, the insulating resin member 12b is placed in a state where the bonding has not yet been carried out in a region surrounded by the flow barrier 11b using the flow barrier 11b, and the module unit 2 is placed on top of the heat sink 10, and heat and pressure are applied to the module unit 2 and the heat sink 10 to Fig. 20. As described above, arranging the insulating resin member 12b after arranging the flow barrier 11b facilitates positioning of the insulating resin member 12b, but the flow barrier 11b and the insulating resin member 12b may also be arranged in the reverse order.

[0084] In the case where, as in Fig. 21, the positioning notch 34 for positioning the flow barrier 11 is formed on the bottom of the module unit 2, the positioning notch 34 for positioning the flow barrier 11 is formed with a die on the bottom of the module unit 2 at the same time as the transfer molding of the module unit 2. Next, as shown in Fig. 22, the flow barrier 11b is arranged in a state in which the bonding has not yet taken place so that it fits into the positioning notch 34 for positioning the flow barrier 11.

[0085] Then, the insulating resin member 12b is placed in a state where the bonding has not yet been carried out in a region surrounded by the flow barrier 11b using the flow barrier 11b, and the heat sink 10 is placed on the lower surface of the module unit 2, and heat and pressure are applied to the heat sink 10 and the module unit 2 to heat the Fig. 23. As described above, the arrangement of the insulating resin member 12b after the arrangement of the flow barrier 11b facilitates the positioning of the insulating resin member 12b, but the flow barrier 11b and the insulating resin member 12b may also be arranged in the reverse order.

[0086] Another example of the method for positioning the flow barrier 11 will be described below. When the flow barrier 11 and the heat sink 10 are made of metal such as aluminum, the flow barrier 11 can be directly bonded to the top of the heat sink 10. Wire bonding with a device such as a wire bonder without forming the positioning notch 33, as shown in Fig. 18, allows the flow barrier 11 to be arranged on the upper surface of the heat sink 10 using a bonding wire. In this case, in addition to solid-state bonding, such as ultrasonic bonding, spot welding by laser welding or the like can also be used as a direct bonding means.

[0087] In the power semiconductor component 100 constructed as described above, a flow barrier 11 is arranged around the insulating resin element 12. This barrier is more easily compressively deformable than the insulating resin element 12, so that even when pressure is applied to the module unit 2 and the cooling unit 13 to connect the module unit 2 and the cooling unit 13, the formation of voids in the edge region of the insulating resin element 12 is suppressed. This enables an increase in the insulation and heat dissipation of the bond between the module unit 2 and the cooling unit 13 and increases the reliability of the power semiconductor component 100. Embodiment 2

[0088] The second embodiment differs from the first embodiment in that a protrusion 22, 23 protruding from the bottom surface of the module unit 2 or the top surface of the cooling unit 13 (the top surface of the heat sink 10) is provided around the insulating resin member 12. As described above, since the protrusion 22, 23 protruding from the bottom surface of the module unit 2 or the top surface of the cooling unit 13 (the top surface of the heat sink 10) is formed around the insulating resin member 12, the flow barrier 11 is compressed by the pressure exerted by the protrusion 22, 23 and a surface facing the protrusion 22, 23, and the formation of voids on the periphery of the insulating resin member 12 is suppressed.

[0089] This makes it possible to increase the insulation and heat dissipation of the connection between the module unit 2 and the cooling unit 13 and to increase the reliability of the power semiconductor device 100. It should be noted that other points are the same as those of the first embodiment, so a detailed description of these points will be omitted.

[0090] Fig. 24 is a sectional view schematically showing a power semiconductor device according to the second embodiment of the present invention. In the drawing, a power semiconductor device 200 includes the module unit 2, the cooling unit 13, the insulating resin member 12, and the flow barrier 11. Furthermore, the module unit 2 includes the power semiconductor element 3, the electrically conductive member 4 having a plate shape, the input / output terminals 6a, 6b, the adhesives 7, 8a, 8b, the sealing member 5, and the protrusion 22 serving as the first protrusion. Furthermore, the cooling unit 13 includes the heat sink 10, the fins 15, and the water jacket 14.

[0091] In the drawing, in the power semiconductor device 200, the module unit 2 and the cooling unit 13 are coupled to each other via the insulating resin member 12. The flow barrier 11 is arranged around the insulating resin member 12 and between the protrusion 22 protruding from the bottom of the module unit 2 and the cooling unit 13 (heat sink 10). That is, the flow barrier 11 is arranged on a surface of the protrusion 22 facing the heat sink 10. The protrusion 22 protruding from the bottom of the module unit 2 is arranged around the insulating resin member 12 and enables the positioning of the insulating resin member 12. The flat shape of the contact surface between the protrusion 22 and the flow barrier 11 is desirably the same as the flat shape of the flow barrier 11.

[0092] As described above, the protrusion 22 and the flow barrier 11 are formed around the insulating resin member 12, so that it is possible to prevent the insulating resin member 12 from flowing out and at the same time suppress the formation of voids in the insulating resin member 12 at the time when the module unit 2 and the cooling unit 13 are bonded to each other by applying heat and pressure.

[0093] Next, an example of manufacturing steps according to the second embodiment of the present invention will be described. The protrusion 22 formed on the bottom surface of the module unit 2 can be formed simultaneously with the formation of the sealing member (molding resin) 5 by transfer molding or the like in the module unit forming step. Subsequently, in the insulating resin member and flow barrier disposing step, a material such as silicone rubber that can be applied and is to form the flow barrier 11 is applied to a portion of the protrusion 22 that is to be the contact surface with the flow barrier 11, and cured by heat treatment or the like to form the flow barrier 11.

[0094] Such a manufacturing step enables the cost-effective production of a resin flow-preventing structure. The protrusion 22 enables the flow barrier 11 to prevent resin from flowing out of the insulating resin member 12 with a thickness smaller than the thickness of the insulating resin member 12.

[0095] Fig. 25 is a sectional view schematically showing another type of power semiconductor device according to the second embodiment of the present invention. In the drawing, a power semiconductor device 201 includes the module unit 2, the cooling unit 13, the insulating resin member 12, and the flow barrier 11. Further, the module unit 2 includes the power semiconductor element 3, the electrically conductive member 4 having a plate shape, the input / output terminals 6a, 6b, the adhesives 7, 8a, 8b, and the sealing member 5. Further, the cooling unit 13 includes the heat sink 10, the fins 15, and the water jacket 14. The heat sink 10 includes a protrusion 23 serving as a second protrusion on the top surface.

[0096] In the drawing, in the power semiconductor device 201, the module unit 2 and the cooling unit 13 are coupled to each other with the insulating resin member 12 arranged therebetween. The flow prevention member 11 is arranged around the insulating resin member 12 and between the projection 23 protruding from the top surface of the heat sink 10 and the module unit 2. That is, the flow barrier 11 is arranged on a surface of the projection 23 facing the module unit 2. The projection 23 protruding from the top surface of the heat sink 10 is arranged around the insulating resin member 12, and the projection 23 enables the positioning of the insulating resin member 12. The planar shape of the contact surface between the projection 23 and the flow barrier 11 is preferably the same as the planar shape of the flow barrier 11.

[0097] As described above, the protrusion 23 and the flow barrier 11 are formed around the insulating resin member 12, so that it is possible to prevent the insulating resin member 12 from flowing out and at the same time suppress the formation of voids in the insulating resin member 12 at the time when the module unit 2 and the cooling unit 13 are bonded to each other by applying heat and pressure.

[0098] An example of the manufacturing steps according to the second embodiment of the present invention will be described below. The protrusion 23 formed on the upper surface of the heat sink 10 is inseparably connected to the heat sink 10 and is formed by machining, preferably by casting or molding with a die, during the manufacture of the heat sink 10. Subsequently, in an insulating resin member and flow barrier disposition step, a material such as silicone rubber that can be applied and is to form the flow barrier 11 is applied to a portion of the protrusion 23 that is to be the contact surface with the flow barrier 11 and cured by heat treatment or the like to form the flow barrier 11. Such a manufacturing step enables the low-cost production of a resin flow barrier structure.By means of the projection 23, the flow barrier 11 can prevent the resin from flowing out of the insulating resin element 12 with a thickness smaller than the thickness of the insulating resin element 12.

[0099] According to the second embodiment, the flow barrier 11 is not necessarily a coating material, and various materials and shapes described in the first embodiment can be used. Even if a standard component (a sealing component with a general thickness) is used in which the thickness of the flow barrier 11 is t 11b in Fig. 3, in this case, adjusting the height of the projection 22, 23 allows the standard component to also prevent resin from flowing out of the insulating resin element 12. This means that the projection 22, 23 serves as an auxiliary element for the flow barrier 11.

[0100] It is also possible to provide both a projection 22 protruding from the bottom of the module unit 2 and a projection 23 protruding from the top of the heat sink 10. In this case, the flow barrier 11 is arranged between the projection 22 and the projection 23. Note that according to the second embodiment, the thickness (height) when at least one of the projection 22 and the projection 23 and the flow barrier 11 is used is t 12 is set as in Fig. 4 and the like are shown as rib shapes.

[0101] In the power semiconductor device 200 constructed as described above, the flow barrier 11, which is more easily compressively deformable than the insulating resin member 12, is arranged around the insulating resin member 12, so that even when pressure is applied to the module unit 2 and the cooling unit 13 to bond the module unit 2 and the cooling unit 13 together, the formation of voids in the periphery of the insulating resin member 12 is suppressed. This makes it possible to enhance the insulation and heat dissipation of the bonding between the module unit 2 and the cooling unit 13 and to increase the reliability of the power semiconductor device 200. Furthermore, the flow barrier 11 is formed on the protrusions 22, 23, thereby eliminating the positioning protrusions 22, 23 and the flow barrier 11.

[0102] Furthermore, the use of the projections 22, 23 enables easy positioning of the insulating resin element 12 relative to the flow barrier 11. Embodiment 3

[0103] The third embodiment differs from the first embodiment in that a flow barrier reinforcement wall 24 and / or 25 and / or 26 is formed around the flow barrier 11, which protrudes from the bottom of the module unit 2 or the top of the cooling unit 13 (the top of the heat sink 10). As described above, the flow barrier reinforcement wall 24, 25, 26, which protrudes from the bottom of the module unit 2 or the top of the cooling unit 13 (the top of the heat sink 10), is formed around the flow barrier 11, so that even under a high pressure that forces the resin to flow out of the insulating resin member 12, the provision of the flow barrier reinforcement wall 24, 25, 26 prevents the resin from flowing out and suppresses the formation of voids in the periphery of the insulating resin member 12.

[0104] This makes it possible to increase the insulation and heat dissipation of the connection between the module unit 2 and the cooling unit 13 and to increase the reliability of the power semiconductor device 300. It should be noted that the other points are the same as those of the first embodiment, so a detailed description of these points is omitted.

[0105] Fig. 26 is a sectional view schematically showing the power semiconductor device according to the third embodiment of the present invention. In the drawing, the power semiconductor device 300 includes the module unit 2, the cooling unit 13, the insulating resin member 12, and the flow barrier 11. Further, the module unit 2 includes the power semiconductor element 3, the electrically conductive member 4 having a plate shape, the input / output terminals 6a, 6b, the adhesives 7, 8a, 8b, the sealing member 5, and the flow barrier reinforcing wall 24. Further, the cooling unit 13 includes the heat sink 10, the fins 15, and the water jacket 14. In the drawing, in the power semiconductor device 300, the module unit 2 and the cooling unit 13 are coupled to each other with the insulating resin member 12 interposed. The flow barrier 11 is arranged around the insulating resin element 12 and between the module unit 2 and the cooling unit 13 (heat sink 10).Furthermore, a flow barrier reinforcement wall 24 is arranged around the flow barrier 11, protruding from the bottom of the module unit 2 toward the top of the heat sink 10. When the module unit 2 and the cooling unit 13 are bonded together, the flow barrier reinforcement wall 24 has a gap to the top of the cooling unit 13 (the top of the heat sink 10).

[0106] As described above, the flow barrier reinforcing wall 24 projecting from the lower surface of the module unit 2 is formed around the flow barrier 11, so that even if the pressure forcing the resin to flow out of the insulating resin member 12 is high at the time of joining the module unit 2 and the cooling unit 13 by applying heat and pressure, it is possible to prevent the flow of the insulating resin member 12 and at the same time suppress the generation of voids in the insulating resin member 12.

[0107] The reinforcing wall 24 for preventing leakage is preferably formed at the same time when the sealing member (molding resin) 5 is formed by injection molding or the like in the step of forming the module unit.

[0108] Next, the effects of the resin flow barrier reinforcing wall 24 will be described.

[0109] Fig. 27 is a sectional view schematically showing a manufacturing step of the power semiconductor device according to the third embodiment of the present invention. Fig. 28 is a sectional view schematically illustrating the manufacturing step of the power semiconductor device according to the third embodiment of the present invention. Fig. 27 illustrates a state in which the module unit 2 and the cooling unit 13 are not yet glued together. Fig. 28 shows a state in which the module unit 2 and the cooling unit 13 are glued together. In the drawings, the flow prevention member 11b serves as a flow barrier in a state where the modular unit 2 and the cooling unit 13 are not yet bonded together, and the insulating resin member 12b serves as an insulating resin member in a state where the modular unit 2 and the cooling unit 13 are not yet bonded together. The flow barrier reinforcement wall 24 is arranged around the flow barrier 11 (11b), and the insulating resin member 12 (12b) is arranged inside the flow barrier 11 (11b).

[0110] As described in the first embodiment of the present invention, the pressure forcing the resin to flow out of the insulating resin member 12 can reach an extremely high value on the order of MPa. At this time, if the flow barrier 11 has an extremely low resistance E sealagainst compression like rubber, only the pressure from the module unit 2 and the heat sink 10, between which the flow barrier 11 is arranged, may not be enough to withstand the pressure that forces the resin to flow out of the insulating resin member 12.

[0111] Therefore, when heat and pressure are applied at the time of joining the module unit 2 and the cooling unit 13, sufficient pressure is applied to the insulating resin member 12 to compress the insulating resin member 12. If the flow barrier reinforcement wall 24 were to come into contact with the top surface of the heat sink 10 in a state where sufficient pressure is not yet applied to the flow barrier 11 and the insulating resin member 12 to compress the flow barrier 11 and the insulating resin member 12, the flow barrier reinforcement wall 24 would receive the pressure from the top surface of the module unit 2.

[0112] As a result, the pressure is not sufficiently applied to the flow barrier 11 and the insulating resin element 12, and the voids present in the insulating resin element 12 are not reduced accordingly, which may lead to poor compressive strength. That is, as in Fig. 28, it is desirable that a relationship of t seal > t w is satisfied, where t seal represents the height of the flow barrier 11 and t w represents the height of the flow barrier reinforcement wall 24. In other words, the height of the flow barrier 11 is greater than that of the flow barrier reinforcement wall 24. In this case, the height of the flow barrier 11 and the height of the insulating resin element 12 are approximately the same, but are defined by the height of the adjacent flow barrier 11 for comparability with the height of the flow barrier reinforcement wall 24.

[0113] On the other hand, the smaller the gap between the flow barrier reinforcement wall 24 and the heat sink 10, the higher the sealing performance against the resin from the insulating resin member 12, and therefore, it is desirable that the gap be as close to zero as possible within a dimensional tolerance. For example, the height (protrusion) of the flow barrier reinforcement wall 24 can be formed in a range between 0.5 and 0.95 times the height (thickness) of the insulating resin member 12. Note that if there is a gap between the flow barrier reinforcement wall 24 and the top surface of the heat sink 10, the flow barrier 11 may partially flow toward the flow barrier reinforcement wall 24.

[0114] As described above, the flow barrier reinforcing wall 24 is formed around the flow barrier 11 and on the bottom of the module unit 2, so that even if the pressure forcing the resin to flow out of the insulating resin member 12 is extremely high at the time of joining the module unit 2 and the cooling unit 13 by applying heat and pressure, flow out of the insulating resin member 12 can be prevented and at the same time, the formation of voids in the insulating resin member 12 can be suppressed.

[0115] Fig. 29 is a sectional view schematically showing another type of the power semiconductor device according to the third embodiment of the present invention. Fig. 30 is a sectional view schematically illustrating another type of the power semiconductor device according to the third embodiment of the present invention.

[0116] In Fig. 29, a power semiconductor device 400 includes the module unit 2, the cooling unit 13, the insulating resin member 12, and the flow barrier 11. Further, the module unit 2 includes a power semiconductor element 3, an electrically conductive member 4 having a plate shape, input / output terminals 6a, 6b, adhesives 7, 8a, 8b, and a sealing member 5. Further, the cooling unit 13 includes the heat sink 10, the fins 15, and the water jacket 14. The heat sink 10 includes a flow barrier reinforcing wall 25 arranged around the flow barrier 11 and protruding from the upper surface of the heat sink 10 toward the lower surface of the module unit 2.

[0117] In the drawing, in the power semiconductor device 400, the module unit 2 and the cooling unit 13 are coupled with the insulating resin member 12 interposed therebetween. The flow barrier 11 is arranged around the insulating resin member 12 and between the module unit 2 and the cooling unit 13 (heat sink 10). Furthermore, a flow barrier reinforcement wall 25 is arranged around the flow barrier 11 and protrudes from the top of the heat sink 10 toward the bottom of the module unit 2.

[0118] The flow barrier reinforcement wall 25 is inseparably connected to the heat sink 10 and can be manufactured by machining, e.g., by cutting, preferably by casting or molding. It should be noted that if a gap exists between the flow barrier reinforcement wall 25 and the bottom of the module unit 2, the flow barrier 11 may partially flow toward the flow barrier reinforcement wall 25.

[0119] As in Fig. 30, a central region of the upper surface of the heat sink 10 may be hollowed out, and the periphery of the hollowed out region may be used as the flow barrier reinforcement wall 26. The flow barrier reinforcement wall 26 may be formed by machining, such as cutting, preferably casting or molding with a die, at the time of manufacturing the heat sink 10, as with the flow barrier reinforcement wall 25 described above.

[0120] As described above, the flow barrier reinforcement wall 25, 26 is formed around the flow barrier 11 and on the top surface of the heat sink 10, so that even if the pressure forcing the resin to flow out of the insulating resin member 12 is extremely high at the time of joining the module unit 2 and the cooling unit 13 by applying heat and pressure, it is possible to prevent the insulating resin member 12 from flowing out and simultaneously prevent the formation of voids in the insulating resin member 12. Furthermore, the relationship between the flow barrier reinforcement wall 25, 26, the flow barrier 11 (11b), and the insulating resin member 12 (12b) is the same as the above-described relationship between the flow barrier reinforcement wall 24, the flow barrier 11 (11b), and the insulating resin member 12 (12b).

[0121] For the module unit 2, a structure was described in which direct lead bonding is applied to the main wire bonding, but bonding with a commonly used aluminum (Al) or copper (Cu) wire, or other bonding methods, may also be used. Furthermore, the module unit 2 is not limited to a transfer-molding type unit and only needs to be capable of applying heat and pressure to the insulating resin member 12.

[0122] As described above, the flow barrier reinforcing wall 25, 26 protruding from the top of the heat sink 10 is formed around the flow barrier 11, so that even at a high pressure forcing the resin to flow out of the insulating resin member 12 when the module unit 2 and the cooling unit 13 are bonded together by applying heat and pressure, the flow out of the insulating resin member 12 can be prevented and the formation of voids in the insulating resin member 12 can be suppressed.

[0123] Furthermore, a structure is provided for the cooling unit 13 in which the heat sink 10, which is commonly used in vehicle-mounted power semiconductor devices, serves as the water-cooled cooling unit 13 portion. However, the cooling system is not limited to water cooling. Furthermore, the heat sink 10 and fins 15 may have not only a structure in which the heat sink 10 and fins 15 are integrally formed, but also other structures and materials suitable for their use.

[0124] In power semiconductor devices 300, 400, 500 constructed as described above, a flow barrier 11 is arranged around the insulating resin member 12, which is more easily compressively deformable than the insulating resin member 12, so that even when pressure is applied to the module unit 2 and the cooling unit 13 to bond the module unit 2 and the cooling unit 13 together, the formation of voids in the periphery of the insulating resin member 12 is suppressed. This makes it possible to increase the insulation and heat dissipation of the bonding between the module unit 2 and the cooling unit 13 and to increase the reliability of a power semiconductor device 300, 400, 500.

[0125] Furthermore, the flow barrier reinforcing wall 24, 25, 26 is formed around the flow barrier 11, so that even if the pressure forcing the resin to flow out of the insulating resin member 12 is extremely high at the time of joining the module unit 2 and the cooling unit 13 by applying heat and pressure, flow out of the insulating resin member 12 can be prevented and at the same time, the formation of voids in the insulating resin member 12 can be suppressed. Embodiment 4

[0126] In the fourth embodiment, the power semiconductor device according to any one of the first to third embodiments is used in a power conversion device. Although the present invention is not limited to a specific power conversion device, a structure in which the present invention is applied to a three-phase inverter will be described below as the fourth embodiment.

[0127] Fig. 31 is a block diagram showing the structure of a power conversion system to which the power conversion apparatus according to the fourth embodiment of the present invention is applied.

[0128] The Fig. The power conversion system illustrated in Figure 31 includes a power supply 1000, a power conversion device 2000, and a load 3000. The power supply 1000 is a DC power supply and supplies DC power to the power conversion device 2000. The power supply 1000 may be composed of various components, such as a DC power system, a solar cell, and a storage battery, or alternatively, a rectifier circuit and an AC / DC converter connected to an AC power system, and the like. Furthermore, the power supply 1000 may be composed of a DC / DC converter that converts the DC power output from the DC power system into a predetermined power.

[0129] The power conversion device 2000 is a three-phase inverter connected between the power supply 1000 and the load 3000, converts the DC power supplied by the power supply 1000 into AC power, and supplies the AC power to the load 3000. As shown in Fig. 31, the power conversion device 2000 includes a main conversion circuit 2001 that converts the DC power supplied from the power supply 1000 into AC power and outputs the AC power, and a control circuit 2003 that outputs a control signal to the main conversion circuit 2001 for controlling the main conversion circuit 2001.

[0130] Here, load 3000 is a three-phase electric motor driven by the AC power supplied by power converter 2000. Note that load 3000 is not limited to a specific application and can be an electric motor mounted in various electrical devices such as a hybrid vehicle, an electric vehicle, a railway car, an elevator, and an air conditioner.

[0131] The following describes details of the power conversion device 2000. The main conversion circuit 2001 includes a switching element and a freewheeling diode included in the power semiconductor device 2002 (not shown), converts the DC power supplied from the power supply 1000 into AC power by switching the switching element, and supplies the AC power to the load 3000. Although there are various specific circuit structures for the main conversion circuit 2001, the main conversion circuit 2001 according to the present embodiment is a two-stage three-phase full-bridge circuit and may consist of six switching elements and six freewheeling diodes, each connected in anti-parallel to a corresponding switching element.

[0132] The main converter circuit 2001 consists of power semiconductor devices 2002 corresponding to any one of the first to fifth embodiments described above, each including switching elements, freewheeling diodes, and the like. Two switching elements of the six switching elements are connected in series to form upper and lower arms, and each of the upper and lower arms forms a corresponding phase (U-phase, V-phase, W-phase) of the full-bridge circuit. The output terminals of the upper and lower arms, i.e., three output terminals of the main converter circuit 2001, are connected to the load 3000.

[0133] The main converter circuit 2001 further includes a drive circuit (not shown) that drives each switching element. The drive circuit may be included in the power semiconductor device 2002 or may be separate from the power semiconductor device 2002. The drive circuit generates a drive signal for driving each switching element of the main converter circuit 2001 and supplies the drive signal to a control electrode of the switching element of the main converter circuit 2001.

[0134] Specifically, in accordance with the control signal of the control circuit 2003 to be described later, a drive signal for switching the switching element to the ON state or a drive signal for switching the switching element to the OFF state is output to the control electrode of each switching element. When the switching element is maintained in the ON state, the drive signal is a voltage signal (ON signal) greater than or equal to a threshold voltage of the switching element, and when the switching element is maintained in the OFF state, the drive signal is a voltage signal (OFF signal) less than or equal to the threshold voltage of the switching element.

[0135] The control circuit 2003 controls each switching element of the main converter circuit 2001 to supply the desired power to the load 3000. Specifically, a time (ON time) during which each switching element of the main converter circuit 2001 is in the ON state is calculated based on the power to be supplied to the load 3000. The main converter circuit 2001 can be controlled, for example, by PWM control, in which the ON time of the switching element is modulated depending on the voltage to be output.

[0136] Furthermore, a control command (control signal) is output to the drive circuit included in the main converter circuit 2001 to output the ON signal to a switching element that should be in the ON state and the OFF signal to a switching element that should be in the OFF state at a specific time. The drive circuit outputs the ON signal or the OFF signal as a drive signal to the control electrode of each switching element according to the control signal.

[0137] In the power conversion device according to the fourth embodiment constructed as described above, power semiconductor devices according to the first to third embodiments are used as the power semiconductor device 2002 of the main conversion circuit 2001, which increases reliability.

[0138] For the present embodiment, an example in which the present invention is applied to a two-level three-phase inverter is described, but the present invention is not limited to such an example and can be applied to various power conversion devices. According to the present embodiment, a two-level power conversion device is used, but a three- or more-level power conversion device may also be applied, or alternatively, the present invention may be applied to a single-phase inverter when power is supplied to a single-phase load. Furthermore, in a case where power is supplied to a DC load or the like, the present invention can also be applied to a DC / DC converter, an AC / DC converter, or the like.

[0139] Furthermore, the power conversion device using the present invention is not limited to a power conversion device applied to a case where the above-described load is an electric motor, and can be used as a power supply device used in, for example, an electrical discharge machine, a laser beam machine, an induction heating cooker, or a non-contact power supply system. Alternatively, the power conversion device can be used as a power conditioner for a photovoltaic system, a power storage system, or the like.

[0140] In particular, when SiC is used as the power semiconductor element 3, the power semiconductor element is operated at higher temperatures compared to Si to optimally utilize the properties of SiC. Such a power semiconductor device equipped with a SiC device requires higher reliability, so the advantage of the present invention of providing a highly reliable power semiconductor device is more effective. List of reference symbols 2 module units 3 Power semiconductor element 4 electrically conductive element 5 Sealing element 6a, 6b Input / output connection 7, 8a, 8b Adhesion promoter 10 heat sinks 11, 11b Flow barrier 12, 12b Insulating resin element 13 Cooling unit 14 Water jacket 15 ribs 22, 23 lead 24, 25, 26 Flow barrier reinforcement wall 31 Positioning advantage 32 Positioning pin 33, 34 Positioning notch 41 Resin 100, 200, 201, 300, 400, 500, 2002 power semiconductor device 1000 power supply 2000 power converter device 2001 Main converter circuit 2003 control circuit 3000 load

Claims

[1] Power semiconductor device comprising: - a modular unit (2); - an insulating resin element (12) connected to the module unit (2); - a cooling unit (13) connected to the module unit (2) with the insulating resin element (12) arranged therebetween; and - a flow barrier (11) arranged between the module unit (2) and the cooling unit (13) to surround the insulating resin element (12), wherein the flow barrier (11) is more easily compressively deformable than the insulating resin element (12); wherein the flow barrier (11) is made of aluminum, indium, tin, an aluminum alloy, an indium alloy, a tin alloy, or rubber. [2] The power semiconductor device according to claim 1, wherein the module unit (2) has a first projection (22) provided outside the insulating resin member (12), and the flow barrier (11) is arranged between the first projection (22) and the cooling unit (13). [3] The power semiconductor device according to claim 1 or 2, wherein the cooling unit (13) has a second projection (23) provided outside the insulating resin member (12), and the flow barrier (11) is arranged between the second projection (23) and the module unit (2). [4] Power semiconductor component according to one of claims 1 to 3, wherein the flow barrier (11) comprises a wire rod and a crossing or joint region of the wire rod arranged around the insulating resin element (12) is arranged at a corner of the insulating resin element (12). [5] A power semiconductor device according to claim 4, wherein a plurality of wire rods are provided. [6] Power semiconductor component according to one of claims 1 to 5, wherein either the module unit (2) or the cooling unit (13) has a positioning notch (33, 34) for positioning the flow barrier (11). [7] Power semiconductor component according to one of claims 1 to 6, wherein either the module unit (2) or the cooling unit (13) has a flow barrier reinforcing wall (24, 25, 26) provided outside the flow barrier (11). [8] Power semiconductor component according to claim 7, wherein the flow barrier (11) has a greater height than the flow barrier reinforcing wall (24, 25, 26). [9] A power semiconductor device according to any one of claims 1 to 8, wherein the insulating resin member (12) is made of a resin-impregnated, highly thermally conductive member. [10] A method for producing a power semiconductor component, the method comprising the following steps: - a module unit forming step for forming a module unit (2); - a cooling unit forming step for forming a cooling unit (13); - a step of arranging an insulating resin member (12) and a flow barrier (11) on the cooling unit (13) to surround the insulating resin member (12) with the flow barrier (11), wherein the flow barrier (11) is more easily deformable by pressure than the insulating resin member (12); and - a step of connecting the cooling unit (13) and the module unit (2), in which the insulating resin member (12) and the flow barrier (11) are pressed together to connect the cooling unit (13) and the module unit (2); wherein the flow barrier (11) is made of aluminum, indium, tin, an aluminum alloy, an indium alloy, a tin alloy, or rubber. [11] A method for manufacturing a power semiconductor device according to claim 10, wherein the step of arranging the insulating resin member (12) and the flow barrier (11) includes directly connecting the flow barrier (11) to the cooling unit (13). [12] A method for manufacturing a power semiconductor device according to claim 10, wherein the step of attaching the insulating resin member (12) and the flow barrier (11) includes applying the flow barrier (11) to either the cooling unit (13) or the insulating resin member (12). [13] Power conversion device comprising: - a main converter circuit (2001) comprising a power semiconductor device (100, 200, 201, 300, 400, 500, 2002) according to one of claims 1 to 9, wherein the main converter circuit (2001) converts and outputs the input power; and - a control circuit (2003) for outputting a control signal to the main converter circuit (2001) for controlling the main converter circuit (2001).

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