JP2017022157A - Power semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power semiconductor device capable of bonding terminals by soldering at relatively low cost without using a heat-resistant resin to form a frame body.SOLUTION: A power semiconductor device comprises: a cooler 50; wiring patterns P1 and P2 arranged on the cooler; switching elements S1 and S2 and rectification elements D1 and D2 connected on the wiring patterns; plate-like leads L2 and L3 having terminal parts L2a and L3a and connection parts L2b and L3b, and connected with the switching elements and the rectification elements via the connection parts; and a frame body 10 that surrounds the wiring patterns, the switching elements and the rectification elements, and to which the terminal parts are fixed. The frame body is configured by at least two divided bodies 10A and 10B. Each divided body is inserted between the cooler and the plate-like lead from a lateral side of the wiring pattern.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power semiconductor device.

  For example, as a power semiconductor device mounted on a vehicle such as a hybrid vehicle or an electric vehicle, a semiconductor element and a wiring pattern are connected by a wire, and the wiring pattern and a terminal (for example, a DC positive terminal or a DC negative terminal) Has been proposed (for example, Patent Document 1).

JP 2013-89784 A

  In the conventional power semiconductor device, a semiconductor module including a semiconductor element, a wiring pattern, and the like is provided on a cooler, the semiconductor module is surrounded by a resin frame, and the frame is filled with an insulating resin.

  However, when joining the constituent members of the semiconductor module by soldering instead of ultrasonic joining, the frame is exposed to a high temperature environment when the solder is melted.

  That is, when joining each structural member by ultrasonic joining, the joining process could be performed after installing the frame on the cooler. However, after the frame is installed on the cooler, when the soldering of the constituent members is performed collectively by a heating furnace, the frame itself is inevitably heated to the solder melting temperature. .

  Therefore, measures such as forming the frame body with a heat-resistant resin so that the frame body is not damaged by high-temperature heat are necessary, and there is a problem that costs increase.

  The present invention has been made in view of the above problems.

  To achieve the above object, a power semiconductor device according to the present invention includes a cooler, a wiring pattern disposed on the cooler, a switching element and a rectifying element connected on the wiring pattern, a terminal unit, and A plate-like lead connected to the switching element and the rectifying element via the connecting part; the wiring pattern; the switching element and the rectifying element are surrounded; and the terminal part is fixed A frame body, and the frame body includes at least two divided bodies, and each of the divided bodies is inserted between the cooler and the plate-like lead from the side of the wiring pattern. Is the gist.

  According to the power semiconductor device of the present invention, since the frame body can be attached after the wiring pattern, the switching element, the rectifying element, and the connection portion are soldered in a high temperature environment, the frame body is formed of a heat resistant resin. Therefore, cost reduction can be achieved.

It is a disassembled side view which shows the structural example during the assembly of the power semiconductor device which concerns on embodiment. It is an exploded plan view showing a configuration example during assembly of the power semiconductor device according to the embodiment. It is a side view which shows the structural example after the assembly of the power semiconductor device which concerns on embodiment. It is a top view which shows the structural example after the assembly of the power semiconductor device which concerns on embodiment. It is a circuit diagram which shows the circuit structural example of the power semiconductor device which concerns on embodiment.

  Hereinafter, an embodiment as an example of the present invention will be described in detail with reference to the drawings. Here, in the accompanying drawings, the same reference numerals are given to the same members, and duplicate descriptions are omitted. In addition, since description here is the best form by which this invention is implemented, this invention is not limited to the said form.

[Power Semiconductor Device According to Embodiment]
(Configuration example)
A configuration example of the power semiconductor device M according to the embodiment will be described with reference to FIGS.

  Here, FIG. 1 is an exploded side view showing a configuration example of the power semiconductor device M according to the embodiment during assembly, and FIG. 2 is an exploded plan view thereof. 1 and 2, reference numeral 500 indicates the structure of the semiconductor module before the frame 10 is attached.

  FIG. 3 is a side view showing a configuration example of the power semiconductor device M according to the embodiment after assembly, and FIG. 4 is a plan view thereof. FIG. 5 is a circuit diagram showing a circuit configuration example of the power semiconductor device M according to the embodiment.

  As shown in FIG. 3 and the like, a power semiconductor device M as an inverter device mainly includes a cooler 50, a semiconductor module structure 500 provided on the cooler 50, and a semiconductor on the cooler 50. It is comprised from the wall part 51 which surrounds the module structure 500, the frame 10 which surrounds the wall part 51, and the insulating resin 200 with which the wall part 51 is filled.

  The cooler 50 is formed by, for example, extrusion molding of copper or aluminum. Although not shown, the cooler 50 may be formed with a flow path for circulating a coolant such as cooling water, or may be provided with fins for air cooling.

  The semiconductor module structure 500 is composed of a metal layer (for example, a Cu layer or the like) to which switching elements S1, S2 made of IGBT or the like and rectifier elements D1, D2 made of a diode are connected to each other. The first wiring pattern P1 and the second wiring pattern P2, the first plate-like lead L1 made of a copper plate or the like connected to the first wiring pattern P1, the switching element S1 arranged on the first wiring pattern P1, and the rectification A second plate-like lead L2 made of a copper plate or the like connected to the upper terminal of the element D1, and a copper plate or the like made of a switching element S2 arranged on the second wiring pattern P2 and the upper terminal of the rectifying element D2 etc. It is composed of three plate leads L3 and the like.

  The wall 51 is erected on the cooler 50 and is formed so as to seamlessly surround the semiconductor module structure 500. Thereby, it can hold | maintain so that the insulating resin which consists of a silicon resin, an epoxy resin, etc. with which the wall part 51 was filled may not leak.

  The wall portion 51 may be configured integrally with the cooler 50 made of copper or aluminum, or may be configured as a separate metal member and brazed on the cooler 50. Good.

  The frame 10 is composed of, for example, two divided bodies 10A and 10B formed of a resin such as PBT (polybutylene terephthalate). As shown in FIG. 1 and FIG. The first wiring pattern P1 and the second wiring pattern P2) are configured to be inserted and engaged in the A1 and A2 directions from the side.

  In addition, the frame 10 is not limited to the case where the frame 10 is configured by two divided bodies 10A and 10B, and may be configured by three or more divided bodies.

  Although not shown, terminals 160a and 160b connected to the temperature sensor, current sensor, and the like are insert-molded in the divided body 10A and exposed from the divided body 10A as shown in FIG.

  Further, each of the divided bodies 10 </ b> A and 10 </ b> B of the frame body 10 includes a locking portion 30 that is locked to the upper ends 51 a and 51 b of the wall portion 51.

  In the configuration example shown in FIG. 1 and the like, the locking portion 30 has an elastic arm portion 31a and a protruding portion 31b formed on the lower side of the distal end of the elastic arm portion 31a.

  A locking surface 31 c is formed on the divided body 10 </ b> A, 10 </ b> B side of the protruding portion 31 b, and the interval between the inner wall of the divided body 10 </ b> A, 10 </ b> B and the locking surface 31 c is formed to match the width of the wall portion 51. Yes. Thereby, when the locking part 30 is locked to the upper ends 51a and 51b of the wall part 51, the divided bodies 10A and 10B are in a state where the outer wall of the wall part 51 and the inner walls of the divided bodies 10A and 10B are in close contact with each other. It fixes to the part 51 (refer FIG. 3).

  Moreover, the frame 10 has a screwing part just under the terminal parts L1a-L3a which plate-like lead L1-L3 has. As shown in FIG. 2 etc., in this Embodiment, as for the screwing part, nut 60a-60c is mounted in the nut holding | maintenance part 15a-15c formed in the upper surface side of each division body 10A, 10B. The nuts 60a to 60c may be insert-molded at the upper ends of the divided bodies 10A and 10B.

  In addition, the above-mentioned latching | locking part 30 is formed in the position lower than the upper end of a screwing part (nut 60a-60c).

  Thereby, when fixing the latching | locking part 30 to the wall part 51, the situation which a plate | board-like lead L1-L3 etc. stresses and deform | transforms by the latching operation (elastic deformation etc.) of the latching | locking part 30 is avoided. be able to.

  Further, as shown in FIG. 3, a clearance C1 is formed between the engaging portion 30 and the plate-like lead L1 and the plate-like lead L2.

  Thereby, the situation where the wall part 51, the cooler 50, and the plate-like leads L1 and L2, both of which are made of metal, are short-circuited can be prevented. Further, by providing the clearance C1, when the locking portion 30 is locked to the upper ends 51a and 51b of the wall portion 51, it is possible to prevent the elastic deformation of the elastic arm portion 31a from being hindered.

  Here, detailed configurations of the wiring patterns P1 and P2 and the plate-like leads L1 to L3 will be described with reference to FIG.

  Formed on the positive terminal L1a formed on the first plate-like lead L1 connected to the first wiring pattern P1, and on the third plate-like lead L3 connected to the switching element S2 and the rectifying element D2 on the second wiring pattern P2. The negative electrode terminal L3a is disposed on one side of the frame 10.

  An AC terminal L2a formed on the second plate-like lead L2 and connected to the switching element S1 on the first wiring pattern P1, the rectifying element D1 on the first wiring pattern P1, and the second wiring pattern P2 includes the frame body 10. It is arranged on the other side.

  Further, in the wall portion 51, the first wiring pattern P1 and the second wiring pattern P2 are arranged close to each other with a predetermined clearance C2 interposed therebetween.

  In addition, bolt holes 20a, 20b, and 20c for fixing to the frame body 10 are formed in the positive terminal L1a, the AC terminal L2a, and the negative terminal L3a.

  As shown in FIG. 1 and the like, a metal bonding pattern 72 formed on one surface (the lower surface in the drawing) of the insulating layer 73 is bonded onto the cooler 50 via a bonding layer 71 such as solder. .

  A first wiring pattern P <b> 1 is formed on the other surface (the upper surface in the drawing) of the insulating layer 73.

  On the first wiring pattern P1, a rectifying element D1 and a switching element S1 are joined via solder layers D1a and S1a.

  The first plate-like lead L1 is formed by bending a copper plate or the like, and has a flat plate-like connection portion L1b, an upright portion L1c, and a terminal portion (positive electrode terminal) L1a.

  The first plate-like lead L1 is joined to the first wiring pattern P1 through a joining layer 75 having a connecting portion L1b made of solder or the like. In this state, the terminal portion (positive electrode terminal) L1a is held at a position where it abuts on the nut 60a and is fixed by a bolt (not shown).

  The second plate-like lead L2 is formed by bending a copper plate or the like, and has a flat plate-like connection portion L2b, an upright portion L2c, and a terminal portion (AC terminal) L2a.

The second plate-like lead L2 is joined to the switching element S1 and the upper terminals S1b and D1b of the rectifying element D1 disposed on the first wiring pattern P1 through the joining layer of the connecting portion L2b made of solder or the like. The switching element S1 and the rectifying element D1 are joined to the first wiring pattern P1 via the lower terminals S1a and D1a. The connection portion L2d of the second plate-like lead L2 is a joining layer made of solder or the like. It is joined to the second wiring pattern P2 via 74.

  In this state, the terminal portion (AC terminal) L2a is held at a position in contact with the nut 60b and is fixed by a bolt (not shown).

  The third plate lead L3 and the like that do not appear in FIG.

  In the configuration example shown in FIG. 3, the insulating resin 200 is filled up to the upper limit of the height of the wall 51.

  When the power semiconductor device M according to the present embodiment is used for driving a three-phase motor or the like, the power semiconductor devices M can be arranged in parallel for each phase.

  In this case, the wall 51 is formed so as to surround the entire power semiconductor device M arranged in parallel. Further, the frame body 10 is configured to surround the entire wall portion 51.

  Further, as shown in FIG. 4, a board terminal block 80 is provided on the second wiring pattern P <b> 2 side in the frame body 10.

  Terminals 160c and 160d are insert-molded on the board terminal block 80.

  As shown in FIG. 4, the terminal 90a and the first wiring pattern P1 of the switching element S1 are connected to the terminals 160a and 160b exposed from the divided body 10A via wires 70a and 70b.

  Further, as shown in FIG. 4, the terminals 160c and 160d exposed from the board terminal block 80 are connected to the terminals 90b of the switching element S2 and the second wiring pattern P2 through the wires 70c and 70d. Yes.

  According to the power semiconductor device M having such a configuration, after the wiring patterns P1 and P2, the switching elements S1 and S2, the rectifying elements D1 and D2, and the connection portions L1b to L3b are soldered in a high temperature environment, the frame body 10 ( Since the divided bodies 10A and 10B) can be attached, it is not necessary to form the frame body 10 (divided bodies 10A and 10B) with a heat-resistant resin, and the cost can be reduced.

  The wall 51 is made of a metal such as copper or aluminum, like the cooler 50, so that the wiring patterns P1, P2, switching elements S1, S2, rectifier D1, D2 and the connecting portions L1b to L3b can be soldered.

(Manufacturing process)
A manufacturing process of the power semiconductor device M according to the present embodiment will be described with reference to FIGS.

  For simplicity of explanation, it is assumed that a structure 500 of a semiconductor module as shown in FIGS. 1 and 2 is formed on the cooler 50.

  Then, the semiconductor module structure 500 is cooled after being heated in a furnace or the like that can be heated to the melting temperature of the solder in order to perform solder bonding between the members. Thereby, solder joining between each member is completed.

  In addition, in the state which performs such solder joining, since the division bodies 10A and 10B which comprise the frame 10 are not assembled | attached yet, the frame 10 itself is not exposed to a high temperature environment. Therefore, the divided bodies 10A and 10B constituting the frame body 10 do not need to be formed of a heat-resistant resin, and can be formed of a relatively inexpensive resin (for example, PBT (polybutylene terephthalate)). The cost of the entire apparatus M can be reduced.

  Next, as shown in FIGS. 1 and 2, the divided bodies 10 </ b> A and 10 </ b> B constituting the frame body 10 are inserted and engaged with the semiconductor module structure 500 from the A1 direction and the A2 direction.

  At this time, when the tapered surface 31d formed on the lower surface of the protrusion 31b of the locking portion 30 comes into contact with the upper ends 51a and 51b of the wall 51, the protrusion 31b is pressed and the elastic arm 31a is moved upward. It is elastically deformed. When the protruding portion 31b gets over the upper ends 51a and 51b of the wall portion 51, the elastic arm portion 31a is elastically restored and the locking surface 31c of the protruding portion 31b and the upper ends 51a and 51b of the wall portion 51 are engaged. The Thereby, each division body 10A, 10B is latched by the wall part 51, and the division bodies 10A, 10B are fixed to the wall part 51 in the state which the outer wall of the wall part 51 and the inner wall of division body 10A, 10B closely_contact | adhered. . At this time, the latching portion 30 is interposed between the plate-like leads L1, L2, L3 and the wall portion 51, so that both are insulated.

  Thereafter, the plate-like leads L1, L2, L3 are fixed to the frame body 10 by inserting bolts (not shown) into the respective terminal portions L1a, L2a, L3a, screwed into the nuts 60a-60c.

  Next, the board terminal block 80 as shown in FIG. 4 is attached to the second wiring pattern P <b> 2 side in the frame body 10.

  Subsequently, the terminals 160a and 160b exposed from the divided body 10A, the terminal 90a of the switching element S1, and the first wiring pattern P1 are connected via wires 70a and 70b by ultrasonic bonding.

  Similarly, the terminals 160c and 160d exposed from the board terminal block 80 are connected to the terminals 90b and the second wiring pattern P2 of the switching element S2 through wires 70c and 70d.

  Next, the wall portion 51 is filled with an insulating resin 200 such as an epoxy resin. In addition, the resin 200 is good to fill with the height of the wall part 51 as an upper limit like the structural example shown in FIG.

  In addition, since the wall part 51 functions as a seal | sticker which prevents the leakage of the resin 200 when filling with the resin 200, the situation which causes a resin leak from the engaging part of the division bodies 10A and 10B is prevented.

  Through such steps, the power semiconductor device M as shown in FIG. 3 is manufactured.

  Although the invention made by the present inventor has been specifically described based on the embodiments, the embodiments disclosed herein are illustrative in all respects and are not limited to the disclosed technology. Should not be considered. That is, the technical scope of the present invention should not be construed restrictively based on the description in the above embodiment, but should be construed according to the description of the scope of claims. All the modifications within the scope of the claims and the equivalent technique to the described technique are included.

  For example, the wiring patterns P1 and P2, the switching elements S1 and S2, the rectifying elements D1 and D2, and the connection portions L1b to L3b are joined using a conductive sintered material instead of soldering using a solder material. You may do it.

M ... Power semiconductor device 10 ... Frame body 10A, 10B ... Divided body 15a-15c ... Nut holding part 20a-20c ... Bolt hole 30 ... Locking part 31a ... Elastic arm part 31b ... Projection part 31c ... Locking surface 31d ... Taper Surface 50 ... Cooler 51 ... Wall portion 60a-60b ... Nut (screwed portion)
70a to 70d ... wire 71 ... bonding layer 72 ... bonding pattern 73 ... insulating layer 74, 75 ... bonding layer 200 ... resin 500 ... semiconductor module structure L1c, L2c, L3c ... upright portion C1, C2 ... clearance D1, D2 ... Rectification element L1 ... 1st plate-like lead L2 ... 2nd plate-like lead L3 ... 3rd plate-like lead L1b, L2b, L2d, L3b ... Connection part L1a ... Positive electrode terminal (terminal part)
L2a ... AC terminal (terminal part)
L3a ... Negative electrode terminal (terminal part)
S1, S2 ... switching element P1 ... first wiring pattern P2 ... second wiring pattern

Claims (5)

A cooler (50);
Wiring patterns (P1, P2) disposed on the cooler;
Switching elements (S1, S2) and rectifier elements (D1, D2) connected on the wiring pattern;
Plate-shaped leads (L2, L3) having terminal portions (L2a, L3a) and connecting portions (L2b, L3b) and connected to the switching elements and the rectifying elements via the connecting portions;
A frame (10) that surrounds the wiring pattern, the switching element and the rectifying element and to which the terminal portion is fixed;
With
The frame is composed of at least two divided bodies (10A, 10B),
Each of the divided bodies is inserted from the side of the wiring pattern between the cooler and the plate-like lead. The wall further includes a wall (51) standing on the cooler so as to surround the wiring pattern, the switching element, and the rectifying element inside the frame,
The power semiconductor device according to claim 1, wherein the wall portion is filled with resin (200).   3. The power semiconductor device according to claim 2, wherein each of the divided bodies of the frame body has a locking portion (30) locked to an upper end of the wall portion.   The locking portion has an elastic arm portion (31a) and a protruding portion (31b) formed below the tip of the elastic arm portion, and a tapered surface (31d) is formed on the lower surface of the protruding portion. The power semiconductor device according to claim 3, wherein the power semiconductor device is provided. The frame body has a threaded portion (nuts 60a to 60c) immediately below the terminal portion of the plate-like lead.
5. The power semiconductor device according to claim 3, wherein the locking portion is formed at a position lower than an upper end of the screwing portion.

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