JPH06252186A - Manufacture of resin-encapsulated semiconductor device and jig for it - Google Patents

Abstract

PURPOSE:To correct warping of the mounting face of an insulating type resin- encapsulated semiconductor device without using a die and provide excellent heat dissipating characteristics by joining a pair of resin-encapsulated semiconductor devices back to back, keeping them at a high temperature under the condition that they are pressed and held and completely curing the resin. CONSTITUTION:The whole heat dissipating plate 2 whereupon a semiconductor pellet 3 is fixed is coated thick on the pellet fixing side and thin on the rear side with resin 6. At least a pair of such resin-encapsulated semiconductor devices whose surface of the resin layer 6b on the rear side is warped by uneven resin contraction at a resin curing process are joined back to back. The devices 1 are kept at a high temperature under the condition that they are pressed and held from the front sides and the warping of the rear side resin layer 6b is corrected in curing the resin 6 completely. For example, a pair of semiconductor devices 1 and 1 pressed and held by a pair of clips 13 and 14 are kept in a high temperature furnace at 150 deg.C for an hour and the resin 6 is completely cured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a jig for manufacturing a resin-sealed semiconductor device, and more particularly to a resin-insulated resin-sealed semiconductor in which the entire front and back surfaces of a heat dissipation board including semiconductor pellets are completely resin-sealed. The present invention relates to a device manufacturing method and a manufacturing jig used for the method.

[0002]

2. Description of the Related Art There are various types of resin-encapsulated semiconductor devices. For example, in the case of power transistors and the like, the semiconductor device can be mounted on a printed wiring board in an electronic device without interposing an insulating plate or the like during mounting. There is a resin insulation type that can be mounted on the printed wiring board as it is.

4 and 5 are a side sectional view and a partially cutaway top view showing the structure of a resin-sealed type semiconductor device 1 of this type of resin insulation type. A semiconductor pellet 3 is formed on a metal heat dissipation substrate 2. Is fixed by a conductive paste or the like, and a lead 4a for leading out the back electrode of the semiconductor pellet 3 is extended from the base end portion of the heat dissipation substrate 2. This lead 4a
On both sides of the surface, the surface electrode of the semiconductor pellet 3 and the thin metal wire 5
Leads 4b and 4c connected with each other are provided. Then, these semiconductor pellets 3, metal wires 5, leads 4
The entire front and back surfaces of the heat dissipation board 2 including the inner ends of b and 4c are covered with an exterior resin 6 such as epoxy resin by resin molding. A hole 7 is formed at the tip of the heat dissipation board 2, and a mounting hole 8 is formed so as to penetrate the exterior resin 6 corresponding to the hole 7.

Further, the exterior resin 6 of the resin-encapsulated semiconductor device 1 is formed by forming a thick resin layer 6a on the upper surface of the heat dissipation substrate 2 on which the semiconductor pellets are fixed to protect the semiconductor pellets 3 and the back surface on which the semiconductor pellets are not fixed. The side is formed of a resin layer 6b which is as thin as possible so as to obtain the insulation of the semiconductor device and the heat dissipation of the semiconductor device. In addition, the thick resin layer 6a on the semiconductor pellet fixing side has a stepped shape at the tip end thereof which is thinner than the pellet fixing side so that the semiconductor device can be easily attached.

The resin-sealed semiconductor device 1 having such a structure is
As shown in FIG. 6, at a predetermined position of the printed wiring board 9,
The mounting surface 10 on the back side is directly placed, and the mounting screw 1
By fixing it by 1 as it is, it can be mounted on the wiring board 9 without interposing an insulating plate or the like. In this case, the exterior resin 6 on the mounting surface 10 side of the semiconductor device 1 is formed of the resin layer 6b that is as thin as possible, and the heat generated from the semiconductor pellets 3 passes through the heat dissipation substrate 2 and the thin resin layer 6b. A structure for effectively radiating heat to the printed wiring board 9 side is adopted.

[0006]

However, such a resin insulation type in which the fixing side of the pellet 3 is thick and the resin layer is thinly formed on the back side in this way to achieve insulation and heat dissipation of the mounting surface 10 of the semiconductor device. In the resin-encapsulated semiconductor device 1 of 1., the shrinkage rate of the thick resin layer 6a portion and the shrinkage rate of the thin resin layer 6b portion are different in the hardening process of the resin molding in the mold cavity of the exterior resin 6, and the thin resin layer on the back surface side is thin. A warp in which the surface of the resin layer 6b is curved like a mountain at the central portion is generated, and a gap 12 is formed between both end portions of the mounting surface 10 and the mounting surface of the printed wiring board 9,
There is a problem in that the heat dissipation characteristics of the resin-insulated resin-sealed semiconductor device 1 are significantly reduced.

[0007] Such a resin-insulated type resin-sealed semiconductor device 1
In order to prevent the warp of the mounting surface 10 in (1), (A) a method of increasing the thickness of the resin layer 6b formed on the back surface side of the heat dissipation board 2, and (B) increasing the thickness of the heat dissipation board 2 itself to mechanically Although a method of giving strength can be considered, the former deteriorates the heat dissipation characteristics of the resin-sealed semiconductor device 1, and the latter increases the material cost of the lead frame of the heat dissipation substrate material, There were drawbacks such as high cost, and neither could be a practical solution.

Therefore, (C) the resin layer 6b on the back surface side of the heat dissipation substrate 2 to which the semiconductor pellet 3 is fixed is resin-molded with the exterior resin 6 such that the central portion is thin and the peripheral portion is thick.
It has also been proposed to make the resin flat after curing (see Japanese Patent Publication No. 3-73141). However, in order to resin-mold the exterior resin 6 so that the back surface of the substrate becomes flat after the resin molding in this manner, the surface of the molding die of the resin molding machine is formed at the central portion of the resin layer on the back surface of the heat dissipation substrate. It is necessary to provide a curved or mountain-shaped gradient to perform fine processing so as to be thin and thick in the peripheral portion, and the die manufacturing cost becomes extremely expensive. In addition, the mold is also a filler resin filler material during resin molding work, especially the curved part inside the mold cavity is easily worn, and maintenance and work management of the mold become complicated, so it is not always an excellent solution. There wasn't.

Therefore, the present invention has been made in view of the above, and is suitable for a warp that occurs on the mounting surface of an insulating resin-sealed semiconductor device without using an expensive mold that requires complicated maintenance. It is an attempt to obtain a good heat dissipation characteristic by making sure measures to bring the resin-sealed semiconductor device into close contact with the printed wiring board.

[0010]

SUMMARY OF THE INVENTION According to the present invention, when a resin-sealed semiconductor device is generally resin-molded in a mold, the molten mold resin is cured while passing through the cavity,
Although it is molded into a predetermined shape, this is not a completely cured resin but a so-called semi-cured stage, and the back surface of the resin-encapsulated semiconductor device is slightly warped. Before the resin is completely cured by heat such as high temperature storage, it is stored at high temperature while correcting warpage by mechanical pressing,
It is configured to completely cure the resin. Therefore, according to the present invention, the entire surface of the heat dissipation substrate to which the semiconductor pellets are fixed is formed by molding the resin layer thick on the pellet fixing side and thin on the back surface side, and the resin layer surface on the back surface side is contracted during the curing process after molding. A pair of resin-encapsulated semiconductor devices that are curved due to the difference in resin thickness are butt-butted with their backsides facing each other, and pressed and clamped from each surface, and then stored at high temperature to completely cure the resin. Thus, the warp of the back surface side resin layer is corrected. Further, according to the present invention, both ends of each front surface of a pair of resin-encapsulated semiconductor devices, which are back to back butted against each other, are pressed and sandwiched by a pair of clips, stored at high temperature, and the warp of the back surface side resin layer is corrected. It is a thing. Further, according to the present invention, the first and second abutments are fixed on a base base, and the side faces are brought into contact with both ends of the pellet fixing side resin layer surface on the pellet side and the mounting hole side, respectively. A fixed support body having a stepped wall surface formed with a surface, and the pellet fixing side resin layer disposed on the side surface side of the fixed support body and facing the first and second contact surfaces. A movable support body having stepped wall surfaces on which third and fourth contact surfaces are formed, which are in contact with the pellet-side surface and the mounting hole-side end portions, respectively, and the movable support body is attached to the movable support body, The movable support is composed of a drive body that moves to the fixed support side, and the back sides are back to back between the first and second contact surfaces and the third and fourth contact surfaces. Surface of a pair of resin-sealed semiconductor devices Was pressed sandwich is for correcting the warpage of the rear surface side resin layer.

[0011]

The warpage of the resin-sealed semiconductor device in which the backside resin layer is curved in the curing process after the resin is molded in the mold cavity is such that the backsides of the warped parts are butted against each other, and these are the front and back surfaces. Then, it is pressed by a clip or a pressing means, and the warp voids arranged back to back on the back surface are pressed to be flattened. At the same time, when straightening with this jig, the exterior resin is completely cured in the high temperature atmosphere of the high temperature furnace,
Hardens with the mounting surface flattened.

[0012]

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is an embodiment of the present invention and is a side view of a straightening process for straightening a warp on the back surface side of a resin-insulated semiconductor device 1 having a pair of resin-sealed semiconductor devices 1.
1 has a structure in which the back surfaces are abutted against each other, and is pressed and supported by a pair of clips 13 and 14 in a sandwiching manner from the front surface sides of both ends.

These pair of resin-encapsulated semiconductor devices 1,
Reference numeral 1 denotes a resin-molded semiconductor device 1 which has not been completely cured by being stored at a high temperature, and has the same external structure as the resin-sealed semiconductor device 1 described in detail with reference to FIGS. That is, this resin-encapsulated semiconductor device 1 is also one in which the entire surface of the heat dissipation substrate 2 to which the semiconductor pellets 3 are fixed has the pellet fixing surface side thick and the back surface side thin, and the molding layers 6a and 6b are molded. Due to the shrinkage during the curing process, the warp with the central portion curved in a mountain shape is generated on the surface of the thin resin layer 6b on the back surface side due to the difference in the thickness of the resin layers. For this reason, gaps 15 and 16 that widen toward the ends are formed between the two abutting mounting surfaces 10 and 10.

As shown in the drawing, the both ends where the voids 15 and 16 are formed are sandwiched by a pair of clips 13 and 14 from both surfaces of the semiconductor device 1 and 1, and the voids are respectively placed. 15, 16 are pressed. The pair of resin-encapsulated semiconductor devices 1 and 1 pressed and sandwiched by the pair of clips 13 and 14 are held in this sandwiched state for 1H in a high-temperature storage furnace set at a high temperature of 150 ° C., for example. The exterior resin 6 is cured by heat and completely cured.

The pair of resin-encapsulated semiconductor devices 1 and 1 thus treated are in the process of curing the resin molding, which is in the process of not being completely cured by heat, that is, in the process of so-called semi-curing. , 16 parts are respectively pressed by the clips 13 and 14 on both end surface sides, the warp curved in the central part in a mountain shape is corrected, and it becomes flat. At the same time, by high temperature storage,
The exterior resin is completely thermoset, and the warp of the back side mounting surface of the pair of resin-sealed semiconductor devices 1 and 1 is corrected.

2 and 3 show an example of a warp correcting jig 17 for a mounting surface used for manufacturing the resin-sealed type semiconductor device of the present invention. It is something to process. This warp straightening device 17 has a structure in which a pair of resin-sealed semiconductor devices 1, one pair of which are back-to-back butted against each other, are mounted in a straightening jig in a row, and pressed from both front surface sides. It is a thing.

That is, the warp correction jig 17 is provided with a long fixed support 19 and a fixed support 1 on a base base 18.
A long movable support 20 is opposed to the side surface of 9 and arranged in parallel. The fixed support 19 is provided on both sides with
First and second contact surfaces 21 and 22 are formed which contact the mounting hole side surface and the pellet portion side surface at both ends of the resin-encapsulated semiconductor device 1, respectively, and the resin-encapsulated semiconductor device 1 is mounted vertically. It is formed on the stepped wall surface so as to be supported.

Further, the movable support 20 is provided on the side surface at a position facing the first and second contact surfaces 21 and 22 of the fixed support 19, and similarly on both sides of the surface of the resin-sealed semiconductor device 1. Third and fourth abutting surfaces 23, 24 that come into contact with the mounting hole side surface and the pellet portion side surface, respectively, are formed,
It is formed on a stepped wall surface for vertically mounting and supporting the resin-sealed semiconductor device 1.

Although not shown, the movable support 20 is fixed on the base base 18 by a slide mechanism or the like.
The drive member 25 is arranged on the 9 side so as to be able to move forward or backward and has a movable support member 20 on the back surface thereof for moving the movable support member 20.
Is provided. Incidentally, as the driving body 25, a driving means such as spring pressure, air pressure, hydraulic pressure or the like is appropriately adopted. Further, the movable supporting member 20 is configured such that the third and fourth abutting surfaces 23 and 24 are formed in a vertically divided structure so as to press both ends of the surface of the resin-sealed semiconductor device 1 in a well-balanced manner.

By using the warp correction jig 17, it is possible to correct the warp of a large number of resin-sealed semiconductor devices at one time, which is suitable for mass production.

[0021]

As described above, according to the present invention, the resin-insulated resin-sealed semiconductor device of the resin insulation type in which the back side mounting surface is warped during the resin curing process in the mold is abutted back to back. Since it is stored at high temperature while being pressed and clamped from each surface, it is possible to correct the warp of the back side mounting surface without using an expensive mold that requires fine processing and complicated maintenance, and heat dissipation is possible. A resin-sealed semiconductor device having excellent characteristics can be easily obtained.

[Brief description of drawings]

FIG. 1 is a side view of a warp correction process of a mounting surface of a resin-sealed semiconductor device of the present invention.

FIG. 2 is a side sectional view of a jig used for warping correction of the resin-sealed semiconductor device of the present invention.

FIG. 3 is a perspective view of FIG. 2.

FIG. 4 is a side sectional view showing a structure of a resin insulation type resin-sealed semiconductor device.

5 is a partially cutaway top view of FIG. 4. FIG.

FIG. 6 is a side view of the mounting structure on the printed wiring board in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Resin-sealed semiconductor device 2 Heat dissipation board 3 Semiconductor pellet 6a Thick resin layer 6b Thin resin layer 10 Mounting surface 12, 15, 16 Gap 13, 14 Clip 17 Warp correction jig 18 Base base 19 Fixed support 20 Movable Support 21 First contact surface 22 Second contact surface 23 Third contact surface 24 Fourth contact surface 25 Driver

Claims (3)

[Claims] 1. A semiconductor device in which the entire surface of a heat dissipation substrate to which semiconductor pellets are fixed is coated with resin to have a thick pellet fixing side and a thin back surface. At least a pair of resin-encapsulated semiconductor devices whose backside resin layer surface is curved are butt-butted with their backsides back to back, and stored at high temperature in a state of being pressed and clamped from each surface side, and the resin is completely removed. A method of manufacturing a resin-encapsulated semiconductor device, which comprises correcting the warp of the back surface side resin layer in the process of curing. 2. A pair of clips are pressed and sandwiched by a pair of clips so that both ends of each surface of a pair of resin-encapsulated semiconductor devices whose backs are back to back are butted against each other and stored at high temperature to correct warpage of the backside resin layer. The method for manufacturing a resin-encapsulated semiconductor device according to claim 1, wherein. 3. A first and second contact surface fixed to a base base and having side surfaces contacting the pellet fixing side and the mounting hole side of the pellet fixing side resin layer, respectively. And a fixed support having a stepped wall surface, and a pellet on the surface of the pellet-fixing-side resin layer, which is disposed on a side surface side of the fixed support and faces the first and second contact surfaces. Side and the mounting hole side are respectively brought into contact with each other, and a movable support body having a stepped wall surface on which third and fourth contact surfaces are formed, and the movable support body mounted on the movable support body, and the movable support body is fixed as described above. A front surface side of a pair of resin-encapsulated semiconductor devices, which is composed of a driving body that moves to a support body side and is mounted between the first and second contact surfaces and the third and fourth contact surfaces. The resin seal is characterized in that the warp of the back side resin layer is corrected by pressing Warpage correction jig for static semiconductor devices.