JPH04342158A - Package of semiconductor device - Google Patents

Abstract

PURPOSE:To provide a package of a semiconductor device which is constituted to realize simplification of attaching structure of a case cover and not to produce formation warp in the case cover. CONSTITUTION:In a package of a semiconductor device which is formed of combination of a heat dissipation base plate 1, a case 2 and a case cover 3 which closes an upper side opening part of the case and which contains a circuit assembly body 4 and sealing resin 5 in the inside thereof, a fitting click 3d which is formed as a hooked projection in several positions of a periphery of a flat cover plate 3c is formed integrally by a resin mold constitute a case cover and an opening edge of a case is inserted between the fitting click and the cover plate to apply and fix the case cover to the case.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to power transistors,
This invention relates to the package structure of semiconductor devices such as diodes and thyristor modules.

0002

2. Description of the Related Art First, FIGS. 4 and 5 show the package structure of a conventional semiconductor device. In the figure, 1 is a metal base plate for heat dissipation, 2 is a resin case surrounding the base plate 1 and fixed with adhesive, and 3 is a case lid that closes the upper opening of the case 2. A module circuit assembly 4 is assembled inside the container of the constructed package, and a sealing resin 5 such as gel-like silicone is further filled to seal the circuit assembly 4. Note that 6 is an external lead-out terminal drawn out from the circuit assembly 4, and 7 is an epoxy resin for fixing the external lead-out terminal 6.

Further, as detailed in FIG. 5, an engaging protrusion 2a is provided on the inner circumferential edge of the upper opening of the case 2, and the outer circumferential edge of the case lid 3 faces the engaging protrusion 2a. A fitting claw 3a is formed on the holder. The engaging pawl 3a is provided so as to protrude toward the outer circumferential side from a rib-shaped edge frame 3b that is bulged on the back side of the case lid 3 over the entire circumference thereof.

[0004] A package having such a configuration is assembled as follows. First, the circuit assembly 4 is mounted and fixed on the base plate 1, and the case 2 is fixed to the base plate 1 with an adhesive. Then, the sealing resin 5 is injected into the case 2 through the upper opening. After that, the case lid 3 is pushed into the upper opening of the case 2 to cover it. As a result, the edge frame 3b of the case lid 3 fits into the opening of the case 2, and at the same time, the engaging claw 3a of the case lid 3 engages with the engaging protrusion 2a of the case 2, and the case lid 3 is fixed. Ru.

[0005]

[Problems to be Solved by the Invention] However, in the conventional configuration described above, the locking structure between the case 2 and the case lid 3 is complicated, and the mold for molding these parts with resin is also complicated. Mold costs are high. Also, case lid 3
Since it has a tray-shaped shape with a rib-like edge frame 3b along its entire periphery, abnormal warping is likely to occur due to resin molding, and this warping reduces the workability of package assembly and the case lid. This is a major cause of unsightly appearance of products equipped with it.

The present invention has been made in view of the above points, and an object of the present invention is to provide a package for a semiconductor device that simplifies the mounting structure of the case lid and prevents molding warpage from occurring on the case lid. do.

[0007]

[Means for Solving the Problems] In order to solve the above problems, in the package of the present invention, the case lid is constructed by partially providing engaging claws at a plurality of locations on the periphery of a flat lid plate, and The case lid is configured to be attached and fixed to the upper opening of the case via the claw.

[0008] Here, the engaging claw mentioned above is a hook-shaped protrusion provided on the back side of the cover plate, and the case lid is fixed to the case by sandwiching the opening edge of the case between the engaging claw and the cover plate. shall be allowed to do so. Note that the case and case lid are made of resin molded products.

[0009]

[Operation] In the above configuration, when attaching the case lid to the case, place the case lid on the top opening of the case, apply force to the case lid from the outside, and warp the case to some extent. Push it into the opening. As a result, the engaging claw fits into the opening edge of the case, thereby locking and fixing the case and the case lid. Note that after the attachment, the case lid returns to its flat state. Moreover, the lid plate of the case lid is a flat plate and has a simple shape with engaging claws distributed and partially provided around the periphery of the lid plate, so that almost no warping occurs due to resin molding.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to FIGS. 1 to 3. In the drawings, members common to FIGS. 4 and 5 are given the same reference numerals. That is, compared to the conventional structure shown in FIGS. 4 and 5, in the illustrated embodiment, first, there is no engagement protrusion on the inner peripheral edge of the opening of the case 2, and instead of this, the plate thickness of the case lid 3 (1 A counterbore portion 2b corresponding to the diameter (approximately .5 mm) is formed. Further, the case lid 3 is constructed by integrally molding engagement claws 3d in the form of hook-shaped protrusions on the back side of the flat lid plate 3c, which are distributed at a plurality of locations around the periphery of the flat lid plate 3c. The rest of the package structure is basically the same as the conventional one.

With this configuration, the circuit assembly 4 is placed inside the package.
, and then inject the sealing resin 5 into the package from the top opening of the case 2, cover the case with the lid 3, apply force from the outside, and push the lid plate 3c in while giving it some warp. The matching claws 3d fit over the opening edge of the case 2. In this state, case 2 is shown in Figure 3.
Since the edge of the opening is sandwiched between the lid plate 3c and the engaging claw 3d from above and below, the case lid 3 is fixed in place.

0012

[Effects of the Invention] Since the package of the present invention is constructed as described above, it achieves the following effects. First, since the case and case lid have a simpler shape than the conventional structure, the molds for molding these parts with resin are inexpensive, which reduces the cost of the product. In addition, the lid plate of the case lid is a flat plate, and the engaging claws are partially formed around the periphery of the lid plate, so there is almost no warping caused by resin molding, and there is little chance of warping during assembly. Improvements can be made in terms of workability and appearance after the case lid is attached.

[Brief explanation of drawings]

[Fig. 1] A cross-sectional view of the configuration of an embodiment of the present invention

[Figure 2] Plan view of the case lid in Figure 1

[Figure 3] Enlarged view of the engaging part of the case lid in Figure 1

[Fig. 4] Cross-sectional diagram of the structure of a conventional package

[Fig. 5] Enlarged view of the engaging part of the case lid in Fig. 4

[Explanation of symbols]

1 Base plate for heat dissipation 2 Case 3 Case lid 3c Lid plate 3d Engagement claw 4 Circuit assembly 5 Sealing resin

Claims (3)

[Claims] 1. A heat dissipating base plate, a case surrounding the base plate, and a case lid closing an opening on the top of the case.
In a semiconductor device package containing a sealing resin,
The case lid is constructed by partially providing engaging claws at multiple locations on the periphery of a flat cover plate, and the case lid is attached and fixed to the upper opening of the case via the engaging claws. Packages for semiconductor devices. 2. The package according to claim 1, wherein the engaging claw is a hook-shaped projection provided on the back side of the cover plate, and the opening edge of the case is sandwiched between the engaging claw and the cover plate to close the case. A semiconductor device package characterized by being fixed to a case. 3. The package for a semiconductor device according to claim 1, wherein the case and the case lid are made of resin molded products.