Power module, and method for manufacturing power module

Abstract

To provide a power module capable of miniaturization without lowering the reliability of a terminal, and a manufacturing method of the power module.SOLUTION: A power module includes a circuit board on which a power semiconductor element is mounted, a base plate to which the circuit board is fixed, a terminal block including a proximal end surface fixed to the surface of the circuit board facing away from the base plate, a distal end surface to which an external conductor electrically connected to the outside can be fixed, and an intermediate portion that extends in a direction away from the surface of the circuit board and electrically connects the proximal end surface and the distal end surfaces, and a reinforcing portion fixed to at least one of the circuit board and the base plate to reinforce the terminal block, and the intermediate portion of the terminal block includes a receiving surface facing the distal end surface side, and the reinforcing portion is provided so as to face the receiving surface in the direction in which the intermediate portion extends, and includes a holding surface that regulates the terminal block displacement in the direction away from the surface of the circuit board.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a power module and a method for manufacturing a power module.

Background Art

[0002] Patent Document 1 discloses, for example, a power semiconductor module (hereinafter referred to as a power module) used in a power conversion device such as an inverter.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the power module as described in Patent Document 1, further miniaturization is desired for improving added value. However, in the input terminals and output terminals of the power module described in Patent Document 1, loads due to disturbances such as loads caused by fastening of conductors and vibrations may be applied. Therefore, it is necessary to have sufficient strength to withstand these loads, and it has become difficult to achieve further miniaturization without reducing the reliability of the terminals.

[0005] The present disclosure has been made to solve the above problems, and an object thereof is to provide a power module and a method for manufacturing a power module capable of achieving miniaturization without reducing the reliability of terminals.

Means for Solving the Problems

[0006] In order to solve the above problems, a power module according to the present disclosure is a power module that converts and outputs input power, and includes a circuit board on which a power semiconductor element is mounted, a base plate to which the circuit board is fixed, a base end surface fixed to a surface of the outer surface of the circuit board facing away from the base plate, a tip end surface to which an external conductor electrically connected to the outside can be fixed, and an intermediate portion extending in a direction away from the surface of the circuit board and electrically connecting the base end surface and the tip end surface. And a terminal block having a reinforcing portion fixed to at least one of the circuit board and the base plate, while exposing the front end face of the terminal block to the outside a reinforcing portion that reinforces the terminal block, wherein the intermediate portion of the terminal block has a receiving surface facing the tip end surface side, and the reinforcing portion is provided so as to face the receiving surface in the extending direction of the intermediate portion, and has a suppressing surface that restricts displacement of the terminal block in a direction away from the surface of the circuit board.

[0007] Further, a method for manufacturing a power module according to the present disclosure includes a base end surface that can be fixed to a circuit board, a tip end surface that can fix an external conductor electrically connected to the outside, and an intermediate portion that electrically connects the base end surface and the tip end surface. A terminal block forming step of forming a terminal block provided with a recess having a receiving surface facing the tip end surface side in the intermediate portion, and supplying a synthetic resin material so as to enter the inside of the recess and covering the intermediate portion of the terminal block. and so as to expose the front end face to the outside And a reinforcing portion forming step of supplying and curing.

Advantages of the Invention

[0008] According to the present disclosure, it is possible to achieve miniaturization without reducing the reliability of the terminals.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

[0010] [First Embodiment] (Power Module) Hereinafter, the power module according to the first embodiment of the present disclosure and the manufacturing method of the power module will be described with reference to the drawings. The power module of this embodiment constitutes a part of a power converter such as an inverter or a converter that converts the input power and outputs it. In this embodiment, a case where the power module constitutes a part of an inverter that takes a direct current as an input and outputs an alternating current will be described as an example.

[0011] FIG. 1 is a perspective view of the power module according to this embodiment, showing the state excluding the reinforcing part. As shown in FIG. 1, the power module 1 of this embodiment includes a base plate 10, a circuit board 15, a terminal block 20, a power semiconductor element 12, a cooler 40, an output conductor 30, and a reinforcing part 50 (see FIG. 3).

[0012] (Base Plate) The base plate 10 is a flat member. The base plate 10 has a first surface 10a and a second surface 10b located on the back side of the first surface 10a. That is, the first surface 10a and the second surface 10b of the base plate 10 are back-to-back. In the present embodiment, for example, copper is adopted for the base plate 10. Note that a metal other than copper may be adopted for the base plate 10.

[0013] (Circuit board) The circuit board 15 has a circuit board body 16 and a circuit pattern C. The circuit board body 16 is flat. This circuit board body 16 has a front surface 16a and a back surface 16b located on the back side of this front surface 16a. The back surface 16b of the circuit board body 16 is fixed to the first surface 10a of the base plate 10 via a bonding material or the like. The circuit board body 16 is formed of an insulating material such as ceramic, for example. Note that as the insulating material forming the circuit board body 16, in addition to the above-mentioned ceramic, paper phenol, paper epoxy, glass composite, glass epoxy, glass polyimide, fluororesin, etc. can also be used.

[0014] The circuit pattern C is a pattern such as a copper foil formed on the front surface 16a of the circuit board body 16. More specifically, the circuit pattern C is formed by fixing it to the front surface 16a of the circuit board body 16 by adhesion or the like and then performing etching or the like. In the circuit pattern C of the present embodiment, an input circuit (not shown), an output circuit (not shown), and a control circuit (not shown) are formed. The input circuit (not shown) is a circuit pattern for inputting the current input from the terminal block 20 described later to the power semiconductor element 12 described later. The output circuit (not shown) is a circuit pattern for outputting the current converted by the power semiconductor element 12. The control circuit (not shown) is a circuit pattern to which a control unit (not shown) that generates a control signal for controlling the behavior of the power semiconductor element 12 is connected.

[0015] (Terminal block) The terminal block 20 receives current input from a current supply source (not shown) provided outside the power module 1 via a capacitor or the like (not shown). As shown in FIGS. 1 and 2, the terminal block 20 is made of a metal such as copper and is fixed to a circuit pattern C formed on the surface 16a of the circuit board body 16. The terminal block 20 has a base end face 20a, a tip end face 20b, and an intermediate portion 20c.

[0016] The base end face 20a is fixed to the surface of the outer surface of the circuit board 15 that faces the side opposite to the base plate 10. More specifically, the base end face 20a contacts the input circuit of the circuit pattern C formed on the surface 16a of the circuit board body 16 and is electrically connected to the input circuit of the circuit pattern C.

[0017] The tip end face 20b is a face located on the side opposite to the base end face 20a. That is, the tip end face 20b and the base end face 20a are in a back-to-back relationship. It is possible to fix a bus bar (not shown) or the like as an external conductor electrically connected to the outside to this tip end face 20b. In the tip end face 20b of the present embodiment, a screw hole T for bolt fastening is formed. By forming this screw hole T for bolt fastening, an input bus bar (not shown), which is an external conductor for current input, can be fastened to the tip end face 20b using a bolt or the like (not shown).

[0018] The intermediate portion 20c extends in a direction away from the surface 16a of the circuit board 15 and connects the base end face 20a and the tip end face 20b. The intermediate portion 20c in the present embodiment extends in a direction perpendicular to the surface 16a of the circuit board 15 from the base end face 20a and reaches the tip end face 20b. The current flowing in from the tip end face 20b of the terminal block 20 reaches the base end face 20a via the intermediate portion 20c and flows into the input circuit of the circuit pattern C from the base end face 20a. In the present embodiment, the contour of the terminal block 20 in a cross section perpendicular to the extending direction of the intermediate portion 20c is rectangular (specifically, substantially square).

[0019] In the middle part 20c, a recess 20d extending in the direction along the circuit board 15 is formed. The recess 20d has a receiving surface 20e facing the tip surface 20b side. Further, the recess 20d in the present embodiment has an opposing surface 20g arranged to face the receiving surface 20e, and a bottom surface 20f connecting the opposing surface 20g and the receiving surface 20e. In the present embodiment, two recesses 20d are formed for one terminal block 20. These two recesses 20d are arranged at positions symmetric to each other in one terminal block 20.

[0020] The power module 1 of the present embodiment has a first terminal block 21 and a second terminal block 22 as two terminal blocks 20 forming a PN terminal. The first terminal block 21 and the second terminal block 22 are arranged side by side at intervals in the direction along the circuit board 15.

[0021] More specifically, the first terminal block 21 and the second terminal block 22 of the present embodiment are arranged at intervals in the extending direction of one side among the four sides of the circuit board 15 formed in a rectangular shape in plan view, and are arranged side by side along this one side.

[0022] From the viewpoint of inductance, it is desirable that the first terminal block 21 and the second terminal block 22 be as close as possible in the direction along the circuit board 15 unless they are in contact. That is, the smaller the gap between the first terminal block 21 and the second terminal block 22 in the direction along the circuit board 15, the greater the influence of the magnetic field generated by the current flowing through these first terminal block 21 and second terminal block 22 can be increased, so that the inductance can be more effectively reduced.

[0023] (Power semiconductor element) The power semiconductor device 12 is, for example, an IGBT, MOSFET, FWD, etc. In this embodiment, a case where six power semiconductor devices 12 are mounted on the circuit board 15 is illustrated. The power semiconductor device 12 includes an input terminal (not shown) and an output terminal (not shown). The input terminal (not shown) is electrically connected to the input circuit of the circuit pattern C formed on the surface 16a of the circuit board main body 16 of the base plate 10 via a bonding material or the like.

[0024] One end of, for example, a lead frame (not shown) as a conducting wire is electrically connected to the output terminal (not shown). The other end of the lead frame is electrically connected to the output circuit of the circuit pattern C. That is, current flows into the input terminal (not shown) via the circuit pattern C, and the current converted by the power semiconductor device 12 is output from the output terminal (not shown). Further, a control signal generated by a control unit (not shown) is input to the power semiconductor device 12. The power semiconductor device 12 performs switching according to this control signal.

[0025] (Cooler) The cooler 40 is a device for cooling the circuit board 15. The cooler 40 is provided on the second surface 10b of the base plate 10 via a bonding material or the like. The cooler 40 in this embodiment has a cooler housing 41, a refrigerant inlet portion 42, and a refrigerant outlet portion 43.

[0026] The cooler housing 41 is joined to the second surface 10b of the base plate 10 via a bonding material or the like. A flow path through which the refrigerant W flows is formed inside the cooler housing 41. The refrigerant inlet portion 42 guides the refrigerant W supplied from a refrigerant supply device (not shown) provided outside the power module 1 into the cooler housing 41. The refrigerant outlet portion 43 discharges the refrigerant W that has flowed into the cooler housing 41 from the refrigerant inlet portion 42 and flowed through the inside of the cooler housing 41 to the outside. The refrigerant discharged from the refrigerant outlet portion 43 is returned to, for example, the refrigerant supply device.

[0027] That is, the heat of the power semiconductor element 12 is transmitted to the refrigerant W through the circuit pattern C, the circuit board body 16, the base plate 10, the cooler housing 41, etc., and the power semiconductor element 12 is cooled.

[0028] For the joining of the base plate 10 and the circuit board body 16, the joining of the power semiconductor element 12 and the circuit pattern C, and the joining of the base plate 10 and the cooler housing 41, for example, joining materials such as solder, sintered materials (powders such as metals and ceramics), and adhesives can be used. Also, in this embodiment, as the materials of the cooler housing 41, the refrigerant inlet portion 42, and the refrigerant outlet portion 43, for example, aluminum, iron, copper, ceramics, etc. can be adopted.

[0029] (Output conductor) The output conductor 30 is a conductor that outputs the current converted by the power semiconductor element 12. The output conductor 30 has a base portion 31 and a connection portion 32.

[0030] The base portion 31 is a conductor as an output bus bar for current output that extends from the outside of the base plate 10 toward the circuit board 15 provided on the first surface 10a. A bolt fastening hole B is formed at the outer end of the base portion 31. An output wiring (not shown) for current output is bolt-fastened to the outer end of the base portion 31.

[0031] The connection portion 32 is connected to the inner end of the base portion 31, extends from the inner end to the circuit pattern C region, and is electrically connected to the output circuit of the circuit pattern C formed on the surface 16a of the substrate body.

[0032] (Reinforcing portion) FIG. 3 is a perspective view of the power module according to this embodiment, showing a state in which a reinforcing portion is provided. As shown in FIG. 3, the reinforcing portion 50 is fixed to a part of the circuit board 15 and the base plate 10 to reinforce the terminal block 20. The reinforcing portion 50 is formed of a synthetic resin material. The reinforcing portion 50 covers the intermediate portion 20c of the terminal block 20 from the outside and surrounds at least the circuit board 15 from the outside. That is, the reinforcing portion 50 forms a case that surrounds the periphery of the circuit board 15 in the direction along the circuit board 15. The reinforcing portion 50 is fixed to the first surface 10a of the base plate 10 and the surface 16a of a part of the circuit board body 16 via an adhesive or the like.

[0033] In the present embodiment, for example, an insulating material such as PPS (polyphenylene sulfide) can be adopted as the synthetic resin material for the reinforcing portion 50. Note that an insulating material other than PPS may be adopted for the reinforcing portion 50.

[0034] The reinforcing portion 50 surrounds the circuit board 15 from the outside. A space is defined by these reinforcing portion 50 and the circuit board 15. Hereinafter, in the present embodiment, the space defined by these reinforcing portion 50 and the circuit board 15 is referred to as a potting space P. A potting material is poured (potted) into the potting space P from the outside, and at least the circuit pattern C and the power semiconductor element 12 provided on the surface 16a of the circuit board body 16 are sealed.

[0035] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 3. As shown in FIG. 4, the reinforcing portion 50 in the present embodiment is shaped so as to enter into a recess 20d formed in the intermediate portion 20c of the terminal block 20. Thereby, a pressing surface 50a is formed on the reinforcing portion 50 so as to face the receiving surface 20e in the extending direction of the intermediate portion 20c of the terminal block 20. The pressing surface 50a restricts the displacement of the terminal block 20 in the direction away from the surface 16a of the circuit board 15.

[0036] Note that, in the present embodiment, a restricting surface 50b that faces the opposing surface 20g of the concave portion 20d is also formed on the reinforcing portion 50. By forming the restricting surface 50b that faces the opposing surface 20g, displacement of the terminal block 20 in the direction approaching the surface 16a of the circuit board 15 is also restricted.

[0037] (Manufacturing Method of Power Module) Next, the manufacturing method of the power module 1 of the present embodiment will be described using the flowchart shown in FIG. 5. The manufacturing method includes at least a terminal block forming step S1, a reinforcing portion forming step S2, a circuit board mounting step S3, and a potting step S4.

[0038] (Terminal Block Forming Step) The terminal block forming step S1 is a step of forming the above-described terminal block 20. In this terminal block forming step S1, first, a metal having a substantially rectangular parallelepiped shape is prepared. In the present embodiment, two metals having a substantially rectangular parallelepiped shape are prepared.

[0039] Next, a screw hole T is formed in one of the two surfaces facing the longitudinal direction of the metal having a substantially rectangular parallelepiped shape. At this stage, the surface on which the screw hole T is formed becomes the front end surface 20b, and the surface on which the screw hole T is not formed becomes the base end surface 20a.

[0040] Next, a groove-shaped concave portion 20d is formed in the intermediate portion 20c between the base end surface 20a and the front end surface 20b of the metal having a substantially rectangular parallelepiped shape in which the screw hole T is formed.

[0041] As a result, a base end surface 20a that can be fixed to the circuit board 15, a front end surface 20b that can fix an external conductor electrically connected to the outside, an intermediate portion 20c that electrically connects the base end surface 20a and the front end surface 20b, and two of the above-described terminal blocks 20 having a concave portion 20d with a receiving surface 20e facing the front end surface 20b side are formed in the intermediate portion 20c.

[0042] (Reinforcing Portion Forming Step) In the reinforcing part forming step S2, the two terminal blocks 20 formed in the terminal block forming step S1 are integrally formed so as to cover the reinforcing part 50 made of synthetic resin.

[0043] In this reinforcing part forming step S2, first, a synthetic resin material is prepared. For example, PPS is adopted as the synthetic resin used in the reinforcing part forming step S2 of the present embodiment. However, a synthetic resin other than PPS may be adopted in the reinforcing part forming step S2.

[0044] Next, for example, the above synthetic resin material is heated and melted, and the synthetic resin is allowed to enter the recesses 20d of the two terminal blocks 20 using a dedicated mold or the like, and is supplied so as to cover the intermediate part 20c of the terminal block 20 from the outside. Then, the synthetic resin is cured. Thereby, the reinforcing part 50 is integrally formed on the two terminal blocks 20. In the reinforcing part forming step S2, a molding method such as insert molding can be used, but a molding method other than insert molding may be adopted.

[0045] (Circuit board mounting step) In the circuit board mounting step S3, the two terminal blocks 20 integrally formed with the reinforcing part 50 in the reinforcing part forming step S2 are mounted on the circuit board 15 fixed to the base plate 10.

[0046] In this circuit board mounting step S3, first, the circuit board 15 fixed to the base plate 10, which is the mounting destination of the terminal block 20, is prepared. Next, a bonding material is applied to a predetermined mounting location of the circuit pattern C formed on the circuit board 15. Examples of the bonding material used in the circuit board mounting step S3 include cream solder, etc., but materials other than cream solder may be adopted as the bonding material in the circuit board mounting step S3.

[0047] Next, the reinforcing portion 50 is mounted on the base plate 10 so that the base end surface 20a of the terminal block 20 contacts the bonding material applied to the mounting location on the circuit board 15. Then, these are placed inside a furnace heated to a predetermined temperature for a predetermined period of time. As a result, the bonding material between the base end surface 20a and the circuit pattern C melts and soldering is completed.

[0048] In the present embodiment, for example, a reflow furnace or the like is employed as the furnace used in the circuit board mounting step S3. Note that a furnace other than a reflow furnace may be employed in the circuit board mounting step S3. By the above procedure, the terminal block 20 with the reinforcing portion 50 formed thereon is mounted on the circuit board 15.

[0049] (Potting Step) In the potting step S4, a predetermined amount of a liquid potting material is poured into the potting space P, and the potting material is cured.

[0050] In the potting step S4, first, a potting material is prepared. As the potting material, for example, silicone gel or epoxy resin can be used. Note that a synthetic resin other than silicone gel or epoxy resin may be used as the potting material.

[0051] On the other hand, in the potting step S4, the reinforcing portion 50 and the base plate 10 are adhered to each other without a gap using an adhesive or the like. As a result, the reinforcing portion 50 is fixed to the base plate 10, and the space between the reinforcing portion 50 and the base plate 10 is sealed. That is, when the potting material is poured into the potting space P, the potting material does not leak from the potting space P.

[0052] Next, a predetermined amount of the potting material is poured into the potting space P. The predetermined amount here means an amount that can cover at least the circuit pattern C formed on the surface 16a of the circuit board main body 16 and the power semiconductor element 12 mounted on the circuit pattern C so that they are not exposed.

[0053] By going through the above series of steps, the power module 1 is manufactured.

[0054] (Function and effect) The power module 1 according to the first embodiment is a power module 1 that converts and outputs the input power, and includes a circuit board 15 on which a power semiconductor element 12 is mounted, a base plate 10 to which the circuit board 15 is fixed, a base end surface 20a fixed to a surface of the outer surface of the circuit board 15 facing away from the base plate 10, a tip end surface 20b to which an external conductor electrically connected to the outside can be fixed, and an intermediate portion 20c extending in a direction away from the surface 16a of the circuit board 15 and electrically connecting the base end surface 20a and the tip end surface 20b. The power module 1 also includes a reinforcing portion 50 fixed to at least one of the circuit board 15 and the base plate 10 for reinforcing the terminal block 20. The intermediate portion 20c of the terminal block 20 has a receiving surface 20e facing the tip end surface 20b side, and the reinforcing portion 50 is provided so as to face the receiving surface 20e in the extending direction of the intermediate portion 20c, and has a suppressing surface 50a for restricting the displacement of the terminal block 20 in a direction away from the surface 16a of the circuit board 15.

[0055] According to the above configuration, the displacement of the terminal block 20 in a direction away from the surface 16a of the circuit board 15 can be restricted by the suppressing surface 50a of the reinforcing portion 50. Therefore, for example, even when vibration occurs in the circuit board 15 during the operation of the inverter or when stress is applied to the terminal block 20 during the manufacture of the power module 1, it is possible to prevent the terminal block 20 from coming off the circuit board 15. Furthermore, since the terminal block 20 can be mounted on the circuit board 15, for example, the input terminal does not extend outside the outer edge of the circuit board 15. Therefore, it is possible to achieve miniaturization without reducing the reliability of the terminals.

[0056] Also, in the power module 1 according to the first embodiment, the reinforcing portion 50 also serves as a case surrounding the periphery of the circuit board 15. According to the above configuration, the number of components can be reduced as compared with the case where the reinforcing portion 50 and the case surrounding the circuit board 15 are provided separately. Further, by surrounding the circuit board 15 with the reinforcing portion 50, the power module 1 can be kept safe.

[0057] Further, in the power module 1 according to the first embodiment, the intermediate portion 20c has a recess 20d extending in a direction along the circuit board 15, and the recess 20d is provided with a receiving surface 20e.

[0058] According to the above configuration, it is possible to regulate not only the displacement of the terminal block 20 in the direction away from the surface 16a of the circuit board 15 but also the displacement of the terminal block 20 in the direction approaching the circuit board 15. Therefore, the load applied to the circuit board 15 can be further reduced.

[0059] Further, the power module 1 according to the first embodiment is provided so as to contact a surface facing the surface on which the circuit board 15 of the base plate 10 is fixed, and further includes a cooler 40 that cools at least the circuit board 15. According to the above configuration, the terminal block 20 fixed to the circuit board 15 can also be cooled using the cooler 40. Therefore, it is possible to cool the external conductor connected to the terminal block 20 via the terminal block 20.

[0060] Further, in the power module 1 according to the first embodiment, a potting space P is defined by the reinforcing portion 50 and the circuit board 15. Therefore, by pouring a potting material into the potting space P defined by the reinforcing portion 50 and the circuit board 15, the circuit pattern C and the power semiconductor element 12 provided on the surface 16a of the circuit board main body 16 can be easily sealed.

[0061] Moreover, the manufacturing method of the power module 1 according to the first embodiment includes a base end surface 20a that can be fixed to the circuit board 15, a tip end surface 20b that can fix an external conductor electrically connected to the outside, and an intermediate portion 20c that electrically connects the base end surface 20a and the tip end surface 20b. A terminal block forming step S1 of forming a terminal block 20 provided with a recess 20d having a receiving surface 20e facing the tip end surface 20b side in the intermediate portion 20c, and a synthetic resin material are supplied so as to enter the inside of the recess 20d and supplied so as to cover the intermediate portion 20c of the terminal block 20 and cured to form a reinforcing portion 50. It includes a reinforcing portion forming step S2.

[0062] According to the above configuration, the reinforcing portion 50 for reinforcing the terminal block 20 can be easily formed.

[0063] [Second Embodiment] Hereinafter, a power module and a manufacturing method of a power module according to a second embodiment of the present disclosure will be described with reference to FIGS. 6 and 7. The reinforcing portion described in the second embodiment is partially different from the configuration of the reinforcing portion 50 included in the power module 1 of the first embodiment. The same components as those in the first embodiment are denoted by the same reference numerals and detailed description thereof is omitted.

[0064] FIG. 6 is a perspective view of a power module according to the second embodiment. As shown in FIG. 6, the reinforcing portion 150 of the power module 1A of the present embodiment is made of a potting material, and the power module 1A further includes an insulating case 60.

[0065] (Insulating Case) The insulating case 60 surrounds the circuit board 15 from the outside. The potting space P is defined by the insulating case 60 and the circuit board 15. In the potting space P in this embodiment, the terminal block 20, the power semiconductor element 12, and the connection portion 32 of the output conductor 30 are arranged. The insulating case 60 is adhered to the first surface 10a of the base plate 10 via an adhesive or the like. The insulating case 60 can be formed of an insulating material such as PPS, which is a synthetic resin. Note that the insulating case 60 may be formed of an insulating material other than PPS.

[0066] (Reinforcing portion) The reinforcing portion 150 in this embodiment is made of a potting material. The reinforcing portion 150 is formed in the potting space P. More specifically, the reinforcing portion 150 is formed so as to fill the potting space P from the surface 16a of the circuit board main body 16 to a position spaced apart from the surface 16a of the circuit board 15 by at least the receiving surface 20e of the recess 20d of the terminal block 20.

[0067] Furthermore, the reinforcing portion 150 is formed so as to enter the recess 20d formed in the intermediate portion 20c of the terminal block 20, similar to the reinforcing portion 150 of the first embodiment. In other words, the reinforcing portion 150 has a suppressing surface 50a facing the receiving surface 20e in the extending direction of the intermediate portion 20c of the terminal block 20. Note that the reinforcing portion 150 can employ, for example, an epoxy resin or the like, but a material other than the epoxy resin may be employed.

[0068] (Manufacturing method of power module) Next, the manufacturing method of the power module 1A of this embodiment will be described with reference to the flowchart shown in FIG. 7. The manufacturing method includes at least a terminal block forming step S1, a circuit board mounting step S2a, a case attachment step S3a, and a reinforcing portion forming step S4a. Note that the description of the terminal block forming step S1 is omitted because it is the same as that of the first embodiment.

[0069] (Circuit board mounting step) After the terminal block forming step S1, a circuit board mounting step S2a is executed. In the circuit board mounting step S2a, the terminal block 20 is mounted on the circuit board 15 fixed to the base plate 10.

[0070] In this circuit board mounting step S2a, first, the circuit board 15 fixed to the base plate 10, which is the mounting destination of the terminal block 20, is prepared. Next, a bonding material is applied to a predetermined mounting location on the circuit pattern C formed on the circuit board 15. Then, the terminal block 20 is mounted on the circuit board 15 such that the base end surface 20a of the terminal block 20 contacts the bonding material applied to the mounting location on the circuit board 15. Thereafter, these are placed inside a furnace heated to a predetermined temperature for a predetermined time. As a result, the bonding material between the base end surface 20a and the circuit pattern C melts and soldering is completed, and the terminal block 20 is mounted on the circuit board 15.

[0071] (Case attachment step) In the case attachment step S3a, an insulating case 60 is attached to the circuit board 15 on which the terminal block 20 is mounted. In this case attachment step S3a, first, the insulating case 60 is prepared. The insulating case 60 can be formed by injection molding or the like using a dedicated mold or the like. Note that the manufacturing method of the insulating case 60 may be another molding method other than injection molding.

[0072] Then, the insulating case 60 is adhered to the base plate 10 via an adhesive or the like so as to cover the circuit board 15 on which the terminal block 20 is mounted from the outside. By the above procedure, the insulating case 60 is attached to the base plate 10.

[0073] (Reinforcing part forming step) In the reinforcing part forming step S4a, a predetermined amount of liquid potting material is poured into the potting space P, and the potting material is cured to form the reinforcing part 150. In this reinforcing portion forming step S4a, first, a potting material is prepared as the material for forming the reinforcing portion 150. As the potting material used in the reinforcing portion forming step S4a, for example, an epoxy resin or the like can be adopted. In addition, a synthetic resin other than the epoxy resin may be adopted as the potting material.

[0074] In the reinforcing portion forming step S4a, next, a predetermined amount of the potting material is poured into the potting space P. At this time, the potting material is poured until it reaches a position that enters at least the recess 20d formed in the intermediate portion 20c of the terminal block 20. Then, the poured potting material is cured. This cured potting material becomes the reinforcing portion 150. Through the above steps, the power module 1A is manufactured.

[0075] (Function and effect) In the power module 1A according to the second embodiment, the reinforcing portion 150 is made of a potting material.

[0076] According to the above configuration, the reinforcing portion 150 that enters the recess 20d of the terminal block 20 can be formed by a simple method of potting. Therefore, the man-hours in the manufacture of the power module 1A can be reduced. Further, by potting, the circuit board 15, the terminal block 20, the power semiconductor element 12, and the insulating case 60 are united by the reinforcing portion 150. Thereby, the strength of the power module 1A against vibrations generated in the circuit board 15 during the operation of the inverter can be improved.

[0077] [Modification example of the embodiment] FIG. 8 shows a modification example of the terminal block of the power module according to the embodiment of the present disclosure. FIG. 8 shows a state excluding the reinforcing portion. The power modules 1 and 1A in the above embodiments may include a first terminal block 21 and a second terminal block 22 that do not have a groove-shaped recess 20d as shown in FIG. 8 as the terminal block 20.

[0078] In this modified example, the first terminal block 21 and the second terminal block 22 are arranged side by side at intervals in the direction along the circuit board 15, similar to the first and second embodiments. In this modified example, the receiving surface 20e of the recess 20d in the middle portion 20c of the first terminal block 21 is provided on the side of the second terminal block 22 rather than the front end surface 20b of the first terminal block 21. Further, the receiving surface 20e of the recess 20d in the middle portion 20c of the second terminal block 22 is provided on the side of the first terminal block 21 rather than the front end surface 20b of the second terminal block 22.

[0079] According to the configuration of the above modified example, the separation distance between the front end surfaces 20b of the first terminal block 21 and the second terminal block 22 can be made larger than the separation distance between the respective receiving surfaces 20e. Therefore, the inductance can be reduced while ensuring the insulation distance between the bolt fastening holes B that are the connection portions with the input bus bar. Further, since the first terminal block 21 and the second terminal block 22 have the receiving surface 20e, the effects described in the above embodiment can be realized.

[0080] [Other Embodiments] As described above, the embodiments and modified examples of the present disclosure have been described in detail with reference to the drawings. However, the specific configuration is not limited to the configuration of each embodiment, and additions, omissions, substitutions, and other changes of the configuration are possible without departing from the gist of the present disclosure. Further, the present disclosure is not limited by the embodiments.

[0081] In the above embodiment, the configuration is such that the screw hole T for bolt fastening is formed in the front end surface 20b of the terminal block 20, but the configuration is not limited to the one in which the screw hole T is formed. For example, a configuration in which a male screw portion protruding from the front end surface 20b is formed may be used.

[0082] Also, in the above embodiment, the middle portion 20c of the two terminal blocks 20 each has two recesses 20d, but the number of recesses 20d is not limited to two. The recess 20d may be one or three or more. In the above embodiment, the recess 20d of the intermediate portion 20c extends in the direction along the circuit board 15, but the configuration is not limited to this.

[0083] In the above embodiment, the power modules 1 and 1A were used in the inverter, but the application is not limited to the inverter. The power modules 1 and 1A may constitute a part of a converter that inputs an alternating current and outputs a direct current, a booster circuit of a regulator that changes the magnitude of the voltage of the direct current, or the like.

[0084] In addition, the order of the steps of the second embodiment is not limited to the above, and the circuit board mounting step S2a and the case attachment step S3a may have different orders.

[0085] [Appendix] The power module described in the embodiment is understood as follows, for example.

[0086] (1) The power modules 1 and 1A according to the first aspect are power modules 1 and 1A that convert and output the input power, and include a circuit board 15 on which a power semiconductor element 12 is mounted, a base plate 10 to which the circuit board 15 is fixed, a base end surface 20a fixed to a surface of the outer surface of the circuit board 15 facing away from the base plate 10, a tip end surface 20b to which an external conductor electrically connected to the outside can be fixed, and an intermediate portion 20c extending in a direction away from the surface 16a of the circuit board 15 and electrically connecting the base end surface 20a and the tip end surface 20b. The power modules 1 and 1A further include a reinforcing portion 50 fixed to at least one of the circuit board 15 and the base plate 10 to reinforce the terminal block 20. The intermediate portion 20c of the terminal block 20 has a receiving surface 20e facing the tip end surface 20b side, and the reinforcing portion 50 is provided so as to face the receiving surface 20e in the extending direction of the intermediate portion 20c and has a suppressing surface 50a that restricts displacement of the terminal block 20 in a direction away from the surface 16a of the circuit board 15.

[0087] According to the above configuration, the displacement of the terminal block 20 in the direction away from the surface 16a of the circuit board 15 can be restricted by the pressing surface 50a of the reinforcing portion 50. Therefore, for example, even when vibration occurs in the circuit board 15 during the operation of the inverter, or when stress is applied to the terminal block 20 during the manufacture of the power module 1, it is possible to prevent the terminal block 20 from coming off the circuit board 15. Further, since the terminal block 20 can be mounted on the circuit board 15, for example, the input terminals do not extend outside the outer edge of the circuit board 15. Therefore, it is possible to achieve miniaturization without reducing the reliability of the terminals.

[0088] (2) The power module 1 according to the second aspect is the power module 1 of (1), and the reinforcing portion 50 may also serve as a case surrounding the periphery of the circuit board 15.

[0089] According to the above configuration, the number of components can be reduced as compared with the case where the reinforcing portion 50 and the case surrounding the circuit board 15 are provided separately. Further, by surrounding the circuit board 15 with the reinforcing portion 50, the power module 1 can be kept safe.

[0090] (3) The power module 1A according to the third aspect is the power module 1A of (1), and the reinforcing portion 150 may be made of a potting material.

[0091] According to the above configuration, the reinforcing portion 150 that enters the recess 20d of the terminal block 20 can be formed by a simple method of potting. Therefore, the man-hours in the manufacture of the power module 1A can be reduced. Further, by potting, the circuit board 15, the terminal block 20, the power semiconductor element 12, and the insulating case 60 are integrated by the reinforcing portion 150. Thereby, the strength of the power module 1A against vibrations generated in the circuit board 15 during the operation of the inverter can be improved.

[0092] (4) The power modules 1, 1A according to the fourth aspect are the power modules 1, 1A according to any one of (1) to (3), wherein the intermediate portion 20c has a recess 20d extending in a direction along the circuit board 15, and the recess 20d may be provided with the receiving surface 20e.

[0093] According to the above configuration, it is possible to restrict not only the displacement of the terminal block 20 in the direction away from the surface 16a of the circuit board 15 but also the displacement of the terminal block 20 in the direction approaching the circuit board 15. Therefore, the load applied to the circuit board 15 can be further reduced.

[0094] (5) The power modules 1, 1A according to the fifth aspect are the power modules 1, 1A according to any one of (1) to (3), and the terminal block 20 includes a first terminal block 21 forming a PN terminal and a second terminal block 22. The first terminal block 21 and the second terminal block 22 are arranged in parallel at intervals in a direction along the circuit board 15. The receiving surface 20e of the first terminal block 21 is provided on the second terminal block 22 side rather than the tip surface 20b of the first terminal block 21, and the receiving surface 20e of the second terminal block 22 may be provided on the first terminal block 21 side rather than the tip surface 20b of the second terminal block 22.

[0095] According to the above configuration, the separation distance between the tip surfaces 20b of the first terminal block 21 and the second terminal block 22 can be made larger than the separation distance between the respective receiving surfaces 20e. Therefore, the inductance can be reduced while ensuring the insulation distance between the bolt fastening holes B that are the connection portions with the input bus bar. Furthermore, since the first terminal block 21 and the second terminal block 22 have the receiving surface 20e, the operational effects described in the above embodiment can be realized.

[0096] (6) The power modules 1, 1A according to the sixth aspect are the power modules 1, 1A according to any one of (1) to (5), and may further include a cooler 40 provided so as to contact a surface facing away from the surface of the base plate 10 to which the circuit board 15 is fixed, for cooling at least the circuit board 15.

[0097] According to the above configuration, the terminal block 20 fixed to the circuit board 15 can also be cooled using the cooler 40. Therefore, it is possible to cool the external conductor connected to the terminal block 20 via the terminal block 20.

[0098] (7) The manufacturing method of the power modules 1, 1A according to the seventh aspect includes a terminal block forming step S1, S1a of forming a terminal block 20 including a base end surface 20a that can be fixed to a circuit board 15, a tip end surface 20b that can be fixed to an external conductor electrically connected to the outside, and an intermediate portion 20c that electrically connects the base end surface 20a and the tip end surface 20b, and the intermediate portion 20c of the terminal block 20 is provided with a recess 20d having a receiving surface 20e facing the tip end surface 20b side; and a reinforcing portion forming step S2, S4a of supplying a liquid synthetic resin so as to enter the inside of the recess 20d and supplying and curing it so as to cover the intermediate portion 20c of the terminal block 20 to form a reinforcing portion 50.

[0099] According to the above configuration, the reinforcing portion 50 for reinforcing the terminal block 20 can be easily formed.

Explanation of Reference Numerals

[0100] 1,1A…Power module 10…Base plate 10a…First surface 10b…Second surface 12…Power semiconductor element 15…Circuit board 16…Circuit board body 16a…Surface 16b…Back surface 20…Terminal block 20a…Base end face 20b…Tip end face 20c…Middle part 20d…Recess 20e…Receiving surface 20f…Bottom face 20g…Opposing face 21…First terminal block 22…Second terminal block 30…Output conductor 31…Base 32…Connection part 40…Cooler 41…Cooler housing 42…Refrigerant inlet part 43…Refrigerant outlet part 50,150…Reinforcing part 50a…Pressing surface 50b…Restricting surface 60…Insulating case B…Bolt fastening hole C…Circuit pattern P…Potting space S1…Terminal block forming process S2,S4a…Reinforcing part forming process S3,S2a…Circuit board mounting process S3a…Case attachment process S4…Potting process T…Screw hole W…Refrigerant

Claims

1. A power module that converts and outputs input power, comprising: A circuit board on which a power semiconductor element is mounted; A base plate to which the circuit board is fixed; A terminal block having a base end surface fixed to a surface of the outer surface of the circuit board facing away from the base plate, a tip end surface to which an external conductor electrically connected to the outside can be fixed, and an intermediate portion extending in a direction away from the surface of the circuit board and electrically connecting the base end surface and the tip end surface; Reinforcing means fixed to at least one of the circuit board and the base plate for reinforcing the terminal block while exposing the tip end surface of the terminal block to the outside. The intermediate portion of the terminal block has a receiving surface facing the tip end surface side; The reinforcing means is: A power module provided so as to face the receiving surface in the extending direction of the intermediate portion and having a restraining surface for restricting displacement of the terminal block in a direction away from the surface of the circuit board.

2. The power module according to claim 1, wherein the terminal block is arranged so as to fit inside the outer peripheral edge portion of the circuit board.

3. The power module according to claim 1 or 2, wherein the reinforcing means also serves as a case surrounding the circuit board.

4. The power module according to claim 1 or 2, wherein the reinforcing means is made of a potting material.

5. The intermediate portion has a recess extending in a direction along the circuit board; The power module according to any one of claims 1 to 4, wherein the recess has the receiving surface.

6. The terminal block includes a first terminal block and a second terminal block forming a PN terminal; The first terminal block and the second terminal block are arranged side by side with a space therebetween in a direction along the circuit board. The receiving surface of the first terminal block is provided on the side of the second terminal block rather than the tip surface of the first terminal block. The power module according to any one of claims 1 to 4, wherein the receiving surface of the second terminal block is provided on the side of the first terminal block rather than the tip surface of the second terminal block.

7. The power module according to any one of claims 1 to 6, further comprising a cooler that is provided so as to contact a surface of the base plate facing away from the surface to which the circuit board is fixed, and that cools at least the circuit board.

8. A terminal block forming step of forming a terminal block including a base end surface fixable to a circuit board, a tip surface fixable to an external conductor electrically connected to the outside, and an intermediate portion electrically connecting the base end surface and the tip surface, and having a recess with a receiving surface facing the tip surface side in the intermediate portion; A reinforcing portion forming step of supplying a liquid synthetic resin so as to enter the inside of the recess, and supplying and curing the synthetic resin so as to cover the intermediate portion of the terminal block and expose the tip surface to the outside to form a reinforcing portion; A method for manufacturing a power module including the above steps.

9. In the reinforcing portion forming step, the synthetic resin is supplied in a state where the terminal block is disposed on the circuit board so as to fit inside the outer peripheral edge portion of the circuit board.

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