JP5823706B2 - Semiconductor device - Google Patents

Description

  The present invention relates to a semiconductor device, and more particularly to a semiconductor device provided with an electrode member into which a bolt for fixing an outer conductor is fitted.

  In a conventional semiconductor device, as shown in FIG. 8, an electrode member 102 on which a bolt 104 for fixing an external conductor 103 is fitted is fixed on a semiconductor chip (or conductor layer) 101 by soldering. . Patent Document 1 discloses an example in which such an electrode member is fixed to a conductor layer on which a semiconductor chip is mounted.

JP-A-9-32216 (see FIG. 1)

  In this conventional semiconductor device, since the electrode structure is simplified, it contributes to a reduction in thickness. On the other hand, when the bolt 104 is attached / detached, a torque acts on the fixing portion F of the electrode member 102 and the electrode member 102 is peeled off. Was. This torque acts as a rotational moment. Therefore, the strength of the fixing force of the electrode member 102 depends on the distance from the center of the fixing portion F, in other words, the distance between the edges (indicated by L1 in the drawing) rather than the size of the area of the fixing portion F. In particular, this electrode member 102 has a taper 102A formed in the lower portion due to manufacturing restrictions, and because the outer diameter decreases toward the fixed portion F, it is difficult to increase the distance between the edges.

  In view of the above-described problems, the present invention provides a semiconductor device using an electrode member to which a bolt for fixing an external conductor is fitted, and suppresses peeling of the electrode member due to torque acting on the fixing portion when the bolt is attached or detached. Objective.

The semiconductor device according to the present invention includes a base plate, a semiconductor chip disposed above the base plate, and a bolt for fixing an external conductor, which is disposed above the semiconductor chip, and is attached to the semiconductor chip. The base plate, the semiconductor chip, and the electrode member are sealed with resin. The electrode member has a columnar shape with a different diameter, the upper part having a large diameter and the lower part having a small diameter, and a metal support member is provided between the electrode member and the semiconductor chip. A leg portion having a height dimension equal to or higher than a height of the lower portion of the small diameter of the electrode member, a leg portion extending in the vertical direction and extending in the center direction of the electrode member, and a lower portion of the electrode member Is disposed in a direction in which at least a pair of the leg portion and the foot portion is opposed to each other with the base portion interposed therebetween,
The support member is fixed on the semiconductor chip by its foot portion , and the electrode member has a small-diameter lower portion fitted into a through-hole in the base portion of the support member, and a bottom surface of the large-diameter upper portion. And is supported and fixed on the base portion of the support member.

  According to this configuration, the electrode member is supported and fixed to the base portion of the support member at the bottom surface of the upper portion having a large diameter. Thereby, the distance between the edges of the fixing portion of the electrode member is increased, and the fixing force with respect to the support member is strengthened.

  In addition, the support member preferably includes a plurality of the leg portions to which the foot portions are continuously provided so that the base portion can be stably supported. For example, if a plurality of leg portions are provided in a line-symmetrical relationship with respect to the base portion, such as forming a leg portion in two directions in a direction facing the base portion in plan view, the support member becomes more stable.

  Further, when the knurling process is performed around the electrode member, the knurled bites into the sealing resin, and a large friction is generated against the rotation in the circumferential direction. Thereby, even if a torque acts on the fixing portion when the bolt is attached or detached, the electrode member can be prevented from easily rotating.

  According to this invention, it becomes possible to suppress peeling of the electrode member due to torque acting on the fixed portion when the bolt is attached or detached.

1A and 1B are a plan view and a front view showing a semiconductor device according to an embodiment of the present invention. FIG. 2 is a sectional view taken along line xx in FIG. 1A showing the semiconductor device. It is a circuit diagram of the semiconductor device. It is an expanded view which shows a supporting member. It is the top view (a) and perspective view (b) which show a support member. It is a decomposition | disassembly elevational view of the principal part of the said semiconductor device explaining the attachment relationship of a semiconductor chip, a supporting member, and an electrode member. The cross-sectional view (a) of the main part of the semiconductor device for explaining the mounting relationship of the semiconductor chip, the support member, and the electrode member according to the present invention is combined with the cross-sectional view (b) of the main part of the semiconductor device according to the prior art. What to show. It is sectional drawing of the principal part explaining the attachment relation of the semiconductor device which concerns on a prior art, a semiconductor chip, a supporting member, and an electrode member.

  A configuration of a semiconductor device according to an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, in the semiconductor device 10 according to this embodiment, a resin case 2 is molded on a base plate 1, and fixtures 13 described later are provided on left and right ends. Further, the electrode member 8 is exposed and embedded on the upper surface of the semiconductor device 10.

  FIG. 2 is a sectional view taken along line xx of FIG. As shown in FIG. 2, the semiconductor device 10 according to this embodiment is large and includes a base plate 1, a semiconductor chip 6, a support member 7, and an electrode member 8.

  The base plate 1 is produced by cutting a plate material of a metal having high thermal conductivity (for example, copper or aluminum) into a predetermined size. The base plate 1 functions as a heat sink for radiating heat generated from the semiconductor chip 6 to the outside.

  The semiconductor chip 6 is disposed above the base plate 1. More specifically, the ceramic substrate 4 is fixed on the base plate 1 with an adhesive or the like, the terminal plate 5 is fixed on the ceramic substrate 4 by soldering, and the semiconductor chip 6 is soldered on the terminal plate 5. Fixed. In the present embodiment, the semiconductor chip is, for example, a diode.

  The terminal board 5 has a shape in which the vicinity of the center of the elongated sheet metal is raised in a convex shape by pressing. The terminal plate 5 is fixed to the ceramic substrate 4 by soldering at the lower surfaces of the mounting portions 51 on both sides formed on the same plane. A through hole 53 is provided in a support portion 52 that protrudes upward and is formed in the center portion of the terminal board 5. An electrode member 8 to be described later is supported and fixed to the support portion 52. The semiconductor chip 6 is fixed on the mounting portion 51 of the terminal board 5 by soldering.

  The electrode member 8 has a concentric two-stage cylindrical shape in which an upper part 81 is formed with a large diameter and a lower part 82 is formed with a small diameter. A bolt hole 83 having a depth that does not penetrate the lower part 82 from the upper surface of the upper part 81 downward is provided in the axial center of the electrode member 8, and the bolt 11 for fixing the external conductor 12 is screwed into the bolt hole 83. It is supposed to be combined. In addition, the external shape of the electrode member 8 is an example, and is not limited to a cylindrical shape, but may be a hexagonal column shape or other rectangular column shape such as a nut.

  The support member 7 is produced from a metal plate material cut into a shape as shown in the developed view of FIG. As shown in FIG. 4, four ear pieces 721 </ b> A to 721 </ b> D having the same length extending from the periphery of the circular base 71 are formed. In the present embodiment, as shown in the figure, paired ear pieces 721A and 721B and ear portions 721C and 721D are respectively formed in two branches. One of the two forked ear pieces 721A and 721C is formed to extend in a direction facing each other with the base 71 interposed therebetween. Similarly, the other forked ear pieces 721B and 721D are also formed to extend in directions facing each other with the base 71 interposed therebetween. In addition, the shape of the base part 71, the number and arrangement | positioning of an ear piece are examples, and are not limited above.

Then, shown in dotted lines in FIG. 4, by a right angle bent so as to mountain fold at sites bending which is two places set on each ear piece 721A～721D, the height of equal vertical direction as shown in FIG. 5 foot 74 is provided continuously on four legs 72A~72D and leg portions extending extending toward the center of the electrode member is formed. The pair of leg part 72A and the foot part 74 connected to the leg part 72A and the pair of leg part 72C and the foot part 74 connected to the leg part 72A are arranged in a direction facing each other with the base part 71 interposed therebetween. A pair of the leg portion 72B and the foot portion 74 connected to the leg portion 72B, and a set of the leg portion 72D and the foot portion 74 connected to the leg portion 72D are also arranged in a direction facing each other with the base portion 71 interposed therebetween. The legs 74 have a purpose of increasing the mounting area when the support member 7 is fixed to the semiconductor chip 6 by soldering, thereby strengthening the mounting. The foot portion 74 protrudes from the leg portions 72 </ b> A to 72 </ b> D inward in a plan view, and the tip thereof reaches the occupied area of the base portion 71. As a result, the mounting area of the support member 7 is not increased by providing the feet 74.

  As shown in FIG. 5, a through hole 73 is formed in the center of the base portion 71 of the support member 7 by pressing. The diameter of the through hole 73 is set to be approximately equal to the diameter of the lower portion 82 of the electrode member 8 so that the lower portion 82 of the electrode member 8 can be fitted. In the present embodiment, the through hole 73 is circular, but the shape of the through hole 73 is determined according to the shape of the electrode member 8 and is not limited to a circular shape.

  As shown in FIG. 7A, the height of the leg portion 72 of the support member 7 (indicated by H1 in the figure) is equal to or higher than the height of the lower portion 82 of the small diameter of the electrode member 8 (indicated by H2 in the figure). Set to the dimensions of Accordingly, the upper portion 81 of the electrode member 8 can be supported on the base portion 71 by fitting the lower portion 82 of the electrode member 81 into the through hole 73. Further, as shown in FIG. 5, although the foot portion 74 of the support member 7 protrudes toward the through hole 73, the lower portion 82 of the electrode member 8 is supported by the rounded tip shape. Even when reaching the vicinity of the lower end of the leg portion 72 of the member 7, it is possible to avoid contact between the lower portion 82 of the electrode member 8 and the foot portion 74 of the support member 7.

  As shown in FIG. 6, the support member 7 is fixed to the semiconductor chip 6 by soldering with a foot portion 74 protruding from the leg portions 72 </ b> A to 72 </ b> D. As illustrated, the semiconductor chip 6 is divided into four corresponding to the four leg portions 72 of the support member 7. Since all the semiconductor chips 6A to 6D are connected to the common terminal plate 5 (see FIG. 2) and the support member 7, they are in a parallel relationship. Thereby, even if a part of the semiconductor chips 6A to 6D breaks down, the operation of the device is not stopped, so that the reliability of the semiconductor device 10 is improved. In addition, the division | segmentation number of the semiconductor chip 6 demonstrated here is only an example. For example, the semiconductor chip 6 can be configured by a two-part product in which the bifurcated legs (72A, 72B) or (72C, 72D) are fixed together.

  As shown in FIGS. 2 and 6, the electrode member 8 has a small-diameter lower portion 82 fitted into the through hole 73 of the base portion 71 of the support member 7 and the bottom surface of the large-diameter upper portion 81. It is fixed on the base 71 by soldering. Further, as shown in FIG. 2, the electrode member 8 is supported and fixed in the same manner to the support portion 52 of the terminal board 5. Thereby, as shown in FIG. 3 as an example of a circuit diagram of the semiconductor device 10, the cathode of the semiconductor chip 6 which is a diode is connected to the electrode member 8 via the terminal plate 5, and the anode of the semiconductor chip 6 is the support member. 7 is connected to another electrode member 8.

  Further, a resin case 2 is molded on the base plate 1. The case 2 houses the ceramic substrate 4, the terminal plate 5, the support member 7, and the electrode member 8, and surrounds them so that the upper surface portion of the electrode member 8 is exposed. The semiconductor device 10 is fastened and fixed to the attached portion at both ends by using the fixtures 13 provided at both ends of the base plate 1 and the case 2. A resin 9 is sealed in the case 2. Thereby, an accommodation component (4-8) is sealed. As shown in FIG. 6, the electrode member 8 is knurled on the periphery, so that the jaggedness bites into the sealing resin 9 and generates a large friction against the rotation in the circumferential direction. Thereby, even if a torque acts at the time of attachment / detachment of the bolt 11, the electrode member 8 can be prevented from easily rotating with respect to the case 2. The outer conductor 12 is fixed to the upper surface of each electrode member 8 exposed to the outside of the sealing resin 9 using bolts 11.

  According to the present embodiment, as shown in FIG. 7A, the electrode member 8 is supported and fixed to the base portion 71 of the support member 7 on the bottom surface of the large-diameter upper portion 81. As a result, the distance between the edges F of the fixed portion of the electrode member 8 (shown as L2 in the figure) is greater than the same distance in the prior art (see L1 in FIG. 7B) (that is, L2> L1). ), The fixing force to the support member 7 is strengthened. Therefore, peeling of the electrode member 8 due to torque acting on the edge F of the fixing portion when the bolt 11 is attached or detached can be suppressed.

  The above description of the embodiment is to be considered in all respects as illustrative and not restrictive. The scope of the present invention is shown not by the above-described embodiments but by the claims. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

DESCRIPTION OF SYMBOLS 1 ... Base plate 2 ... Case 6, 6A-6B ... Semiconductor chip 7 ... Support member 8 ... Electrode member 9 ... Sealing resin

Claims (5)

A base plate,
A semiconductor chip disposed above the base plate;
An electrode member disposed above the semiconductor chip and fitted with a bolt for fixing an outer conductor, and connected to the semiconductor chip;
In the semiconductor device in which the base plate, the semiconductor chip, and the electrode member are sealed with resin,
The electrode member has a columnar shape with different diameters in which the upper part has a large diameter and the lower part has a small diameter,
A metal support member is provided between the electrode member and the semiconductor chip,
The support member includes a leg portion having a height dimension equal to or greater than a height of the lower portion of the small diameter of the electrode member, a leg portion extending in the vertical direction, and a foot portion extending in the center direction of the electrode member. It has a base part in which a through hole into which the lower part of the electrode member is inserted is formed, and is disposed in a direction in which at least a pair of the leg part and the foot part are opposed to each other with the base part interposed therebetween,
The support member be secured by the foot portion on said semiconductor chip, said electrode member, together with the lower portion of the smaller diameter is fitted into the through hole of the base portion of the support member, the upper portion of the large-diameter The semiconductor device which is supported and fixed on the base part of the supporting member at the bottom surface.   2. The semiconductor device according to claim 1, wherein each set includes a plurality of leg portions and foot portions arranged in directions facing each other with the base portion interposed therebetween.   The semiconductor device according to claim 2, wherein the leg portion and the foot portion of each set are formed in two forks.   4. The semiconductor device according to claim 2, wherein the semiconductor chip is divided into a plurality of parts corresponding to the legs and feet of each set, and the legs of each set are fixed to each semiconductor chip. 5.   The semiconductor device according to claim 1, wherein a knurling process is performed around the electrode member.

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