JPH0198250A - Resin-sealed semiconductor device - Google Patents

Abstract

PURPOSE:To prevent a short-circuit accident at the end section of a collector lead completely by sealing an insulating supporter, a chip loading section and a semiconductor chip into a resin molded form and positioning the underside of the chip loading section at a fixed distance from the underside of the resin molded form by the insulating supporter. CONSTITUTION:A base lead, an emitter and an external leading-out section 1B for a collector lead 1 are positioned onto the edge section of a recessed section 21 in a molding bottom force 20A in a lead frame 19 to which a chip 3 is loaded and wire bonding is completed, and the lead frame is placed onto the molding bottom force so that a chip loading section 1A for the collector lead 1, a collector lead nose section 1C1, to which an insulating supporter 13 is fixed, and the base lead and a wire bonding section for the emitter are positioned onto the recessed section 21. A molding top force 20B is lowered, and a resin is injected into a cavity section shaped between the molding bottom force 20A and the molding top force 20B and the chip 3 is molded with a resin. The sides of the nose sections 1C1 and 1C2 of the collector lead 1 are supported in required height by the insulating supporter 12.

Description

[Detailed Description of the Invention] [Summary] Regarding the structure of a resin-sealed semiconductor device, particularly an insulated high-voltage, high-output resin-molded transistor, a collector to which a high voltage is applied in an insulated-type high-voltage, high-output resin-molded transistor. A chip on which a semiconductor chip is mounted, with the purpose of providing a structure in which the end of the lead that does not function as a current-carrying lead is sealed inside a resin molding, completely preventing short-circuit accidents at the end of the collector lead. A lead having a mounting part and an external lead-out part connected to one side of the chip mounting part, and an insulating support fixed to the opposite end of the chip mounting part, the insulating support; The chip mounting part and the semiconductor chip are enclosed in a resin molded body, and the lower surface of the chip mounting part is positioned a predetermined distance from the lower surface of the resin molded body by the insulating support.

[Industrial application field]

The present invention relates to a resin-molded semiconductor device, and particularly to the structure of an insulated high-voltage, high-output resin-molded transistor.

Insulated high voltage, high output resin molded transistors are manufactured by covering the lower surface of the chip mounting portion of the collector lead to which a high voltage is applied to a required thickness with molding resin, thereby creating a bond between the lower surface of the collector lead and the transistor. The side surface of the resin molded body has a structure that maintains high dielectric strength between it and the heat dissipation fins, etc. to which the collector lead is fixed, but the cut end surface of the side that does not function as a current-carrying lead of the collector lead faces the lead extraction surface. Due to the exposed structure, contact or adhesion of conductive foreign matter to the cut end surface of the collector lead, or discharge from the end surface may cause a short circuit between the collector lead and adjacent components, resulting in poor device performance. There is a problem of deterioration, and improvements are desired.

[Conventional technology]

FIG. 6 is a perspective plan view (al and its A-A
Cross-sectional view (bl).

In the figure, 51 is a collector lead, 51A is a chip mounting part of the collector lead formed particularly thick for heat dissipation effect, 51B is an external lead-out part of the collector lead, and 51C1
51C2 is the tip of the collector lead, 51D+, 51D
2 is a cut end surface of a collector lead, 52 is solder for chip fixation, 53 is a transistor chip, 54 is a base lead, 55 is an emitter lead, 56 is a base electrode, 57 is an emitter electrode, 58 and 59 are bonding wires, 60
60A indicates a resin molded body, and 60A indicates a resin molded body layer having a thickness that ensures a required dielectric strength of about 0.4 to 0.5 mm.

As shown in the figure, insulated high-voltage, high-output resin-molded transistors are particularly thick for heat dissipation.
(about 2 to 311) The lower surface of the formed collector lead 51 to the chip mounting portion 51 is embedded in the molded resin molded body 60, and the lower surface of the resin molded body 60 and the chip mounting portion 51A of the collector lead are 0.4 to 0.4 to ensure high insulation between the collector lead 51 to which a high voltage is applied and the radiation fin to which the high voltage and high output resin molded transistor is directly fixed. It is characterized by having a structure in which a molded resin molded body layer 60A with a thickness of about 0.5 mm is interposed, but in the conventional structure shown in FIG. 6 above, when forming this,
Schematic plan view of Fig. 7 (al and its A-A sectional view (b)
A molding method as shown in is used.

That is, the lead frame 62 on which the semiconductor chip 52 is mounted and wire bonding similar to that shown in FIG.
1A and the bonding wire connecting portion between the base lead 54 and the emitter lead 55 are positioned and placed on the recess 63 of the lower mold 61A, and the required distance of, for example, 0.4 to 0.5 vna from the bottom surface of the portion 63 is placed. The base lead 54 of the lead frame, the emitter lead 55, the collector lead lead-out part 51B, and the extension part of the collector lead tip 51C and 51C2 pass through the upper surface of the lower mold 61A so that the height (h) is reached. It is then supported and molded. In the figure, 61B indicates the upper mold.

After the molding is completed, the extended portions of the tip portions 51C+ and 51C2 of the collector lead 51, which extend outside the resin molded body 60 and have no function since the product becomes a product, are connected to the collector lead tip portion 51C+151cz side. Conventional insulated high-voltage, high-output molded transistors were completed by cutting along the sides of the resin molding.

[Problem that the invention seeks to solve]

As mentioned above, in the conventional insulated high-voltage, high-output resin-molded transistor, after molding is completed, the collector lead tip 5, which was used to support the lead frame during molding,
Since 1C and 51C2 cuts are made, the resin molded body 60
It had a structure in which the cut end surfaces 510 and 51D2 of the collector leads 51 were exposed on the side surface facing the lead lead-out surface.

However, in the insulated high-voltage, high-output molded transistor, a high voltage of 1000 V or more is applied to the collector lead 51, so the cut end surface 510 of the collector lead 51 is placed on the side surface of the resin molded body 60 as in the conventional structure. 5
When 1D2 appears, discharge or contact with a conductive foreign object,
Due to such adhesion, a short circuit occurs with the heat dissipation fin to which the transistor is fixed and other electronic components arranged in high density, resulting in a problem that the performance of the transistor is impaired.

Accordingly, the present invention provides an insulated high-voltage, high-output resin-molded transistor in which the end of the collector lead to which a high voltage is applied, on the side that does not function as a current-carrying lead, is embedded inside a resin molding, and the collector lead end The purpose is to provide a structure that completely prevents short-circuit accidents.

[Means for solving problems]

The above problem is caused by a lead having a chip mounting part on which a semiconductor chip is mounted, an external lead-out part connected to one side of the chip mounting part, and a lead fixed to the opposite end of the chip mounting part. an insulating support body, the insulating support body, the chip mounting part, and the semiconductor chip are encapsulated in a resin molded body, and the bottom surface of the chip mounting part is spaced a predetermined distance from the bottom surface of the resin molded body by the insulating support body. This problem is solved by the resin-sealed semiconductor device according to the present invention, which is located in the resin-sealed semiconductor device.

[For production]

That is, in the present invention, the end of the collector lead that is not used as the current-carrying lead is cut short so that it is sunk to a required depth from the side surface of the resin molded body toward which the end is directed, and then It has heat resistance to the extent that it can withstand the temperature of chip welding, and the thickness of the collector lead (the required distance from the bottom surface of the recess of the resin mold that defines the bottom surface of the formed chip mounting part to the bottom surface of the resin molded body). An insulating support having an external shape that can be held at a separate position is fixed, thereby ensuring the required resin thickness with the required dielectric strength voltage and thermal conductivity in the lower region of the chip mounting portion of the collector lead □ during resin molding. do.

In this way, it becomes possible to mold the collector lead by burying the end of the collector lead to a required depth from the side of the resin molded body toward which the end faces, thereby eliminating the short circuit that conventionally occurred at the end of the collector lead. Failure is completely prevented.

〔Example〕

The present invention will be specifically explained below with reference to illustrated embodiments.

FIG. 1 is a perspective plan view schematically showing an embodiment of the present invention (
a), its A-A sectional view (b), and FIG. 2 are plan views (al
and a side sectional view (b), and FIG. 3 is a plan view (a) and A-
A sectional view (b), FIG. 4 is a schematic side sectional view showing a method of fixing an insulating support in an embodiment of the present invention, and FIG. 5 shows a method of resin molding in an embodiment of the present invention. It is a schematic side sectional view.

Identical objects are indicated by the same reference numerals throughout the figures.

In FIGS. 1(a) and 1(fb) showing an embodiment of an insulated high voltage high output resin molded transistor according to the present invention,
1 is the collector lead, IA is the chip mounting part of the collector lead, which is especially thick to about 2 to 3 nm in order to improve heat dissipation of the transistor chip, IB is the external lead-out part of the collector lead, and IC1 and IC2 are the cutting parts of the collector lead. Functions for energization when the end faces ID+ and IDz are cut to a length set back a predetermined distance of about 0.4 to 0.51 to ensure the required dielectric strength voltage of about 100 OV from the side of the resin molded body facing the lead lead-out surface. The tip of the collector lead that does not
2 is a solder for fixing the chip, 3 is a transistor chip, 4 is a base lead, 5 is an emitter lead, 6 is a base electrode,
7 is an emitter electrode, 8 and 9 are bonding wires,
10 is a resin molded body, IOA is a required thickness of about 0, 4 to 0.5+n (tl
); 11 is a bent portion of the tip of the collector lead such that the tip of the collector lead is located approximately at the center of the thickness (t2) of the resin molded body covering the tip; 1;
2 indicates an insulating support.

The insulating support 12 in the above embodiment in which the tip portions IC+ and ICz of the collector lead 1 are bent is, for example, a resin molded material that covers the tip portions IC+ and ICz of the collector lead 1, as shown in FIGS. 2(a) and (bl). Body thickness (t2)
For example, (
A lead insertion hole 14 is formed by sintering glass material inside a copper ring 13 with a thickness of Q, 4**, which has a very small outer diameter of about 1.05 mm, and has a lead insertion hole 14 in the center.
It has a structure in which a glass tablet 15 having a shape is press-fitted. Note that the copper ring was used because it has good adhesion to the mold resin.

Further, the lead frame in the above embodiment is, for example, a third
As shown in Figures (al and bl), the collector lead 1 has a structure in which it is cantilevered by the exterior 16 on one side. The tip part IC+ of the collector lead 1 is cut short so as to be buried in the collector lead 1, and is bent so that the tip part IC+, 1C2 is located at the center of the thickness of the resin molded body covering the part, as described above.
The insulating support 12 having the structure shown in FIG. 2, for example, is fixed to the ICz. In addition, in the figure, 17 indicates a middle crosspiece which will be cut and removed later.

The tip of the collector lead of the above lead frame IC+
, the fixation of the insulating support 12 to the ICz is performed, for example, by the fourth
As shown in the figure, the heating element 1 is placed on the carbon heating element 18.
Arranged in parallel with the same orientation at a predetermined interval through the recesses on 8 sides,
For example, I
The tips IC+ and ICz of each collector lead 1 in a continuous lead frame of approximately O series are inserted, and the carbon heating element 18 is heated to a temperature of 400 to 500, for example.
This can be easily done by heating the glass tablet 15 to about .degree. C. and melting it before mounting the chip on the lead frame.

An insulated high voltage high output resin molded transistor shown in an embodiment of the present invention uses a lead frame having the above structure,
As shown in FIG. 1, the collector lead 1 of the lead frame is connected to the chip fixing solder 2 made of lead solder or the like.
A transistor chip 3 is fixed on the chip mounting part IA of the transistor chip 3, and the base electrode 6 and emitter electrode 7 of the transistor chip 3 are connected to the base lead 4 and emitter lead 5 of the lead frame by bonding wires 8 and 9, respectively. After that, a resin mold is made.

FIG. 5 is a diagram showing the method of resin molding in this embodiment.

As shown in the figure, the lead frame 19 on which chip mounting has been completed and wire bonding (not shown) has been completed is placed above the ti group of the concave portion 21 of the lower mold 20^ and at the external lead-out portions of the base lead, emitter, and collector lead 1 (not shown). IB is located, and the chip mounting part 1^ of the collector lead 1, the collector lead tip IC8 to which the insulating support 12 is fixed, and the wire bonding parts of the base lead and emitter (not shown) are located on the recess 21. Place the mold on the lower mold as shown, and then place the upper mold 2
Descend 0B, mold lower mold 20A and mold upper mold 20
Resin is injected into the cavity formed between B and B to form a resin mold.

In the cough embodiment, one side of the lead frame is supported by the external lead-out portions of the base lead and emitter lead (not shown) and the external lead-out portion IB of the collector lead 1, and the tip IC of the collector lead 1 and the IC (not shown). , are supported at a required height by the insulating support 12, so that the distance between the bottom surface of the chip mounting portion IA of the collector lead 1 and the bottom surface of the recess 21 of the lower mold 2OA is the same as that of the collector lead 1. Chip mounting part IA
It is maintained at a predetermined dimension corresponding to the thickness of the molded resin layer of, for example, about 0.4 to 0.5 fl to be provided at the bottom,
A resin mold is made. As a result, the thickness of the molded resin layer covering the lower surface of the chip mounting portion IA of the collector lead l is formed to a required uniform thickness.

Further, as described above, the tip ends IC+ and ICz of the collector lead 1 to which the insulating support 12 is fixed are approximately 0.4 to 0.5 times away from the side face of the lead tips IC+ and IC2 in the resin molded body. Since the collector lead tips IC+ and ICg to which the insulating support 12 is fixed are cut to a length that is set back the required distance to ensure the dielectric strength of the insulating support 12, It is located at a place set back the required distance from the side surface toward which the collector lead tips IC+ and lc2 face, and when molded with the resin, the upper part of the end face IDz, etc. of the collector lead tip IC+ is formed into a molded resin layer of the required thickness. covered by.

Therefore, short-circuit accidents caused by electrical discharge and adhesion of conductive foreign matter at the tip surfaces IDI and ID2 of the collector leads 1 are completely prevented.

In the above embodiment, the tip of the collector lead was bent to be at the center of the thickness of the resin molded body covering the tip, but the tip of the lead may of course not be bent. However, in this case, the lead insertion hole of the glass tablet needs to be formed at a position shifted upward by a required distance from the center of the tablet.

Furthermore, the insulating material used for the insulating support having the structure shown in FIG. 2 is not limited to the above-mentioned glass tablets, but heat-resistant resin tablets such as diallyl phthalate or silicone may also be used.

Furthermore, the insulating support may be a molded body made only of the heat-resistant resin without using the copper or other metal ring.

〔Effect of the invention〕

As explained above, according to the present invention, in an insulated high-voltage, high-output resin-molded transistor, the resin thickness of the lower region of the chip mounting portion of the collector lead in the resin molded body is adjusted to the required dielectric strength voltage and required thermal conductivity. A state in which the resin molded body is covered with a resin of a required thickness that maintains the required thickness, does not expose the cut end surface of the collector lead on the side opposite to the lead lead-out surface, and provides the required dielectric strength. Resin molding can be done with.

Therefore, short-circuit accidents at the cut end of the collector lead, which were caused by discharge, adhesion of conductive foreign matter, etc., are completely prevented.
The performance of the insulated high voltage, high output resin molded transistor is ensured.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an embodiment of the present invention; FIG. 2 is a schematic diagram of an insulating support in an embodiment of the present invention; FIG. 3 is a schematic diagram of a lead frame in an embodiment of the present invention; Fig. 4 is a schematic side sectional view showing a method of fixing an insulating support in an embodiment of the present invention, Fig. 5 is a schematic side sectional view showing a method of resin molding in an embodiment of the invention, and Fig. 6 is a conventional structure. FIG. 7 is a schematic diagram showing a method of resin molding of a conventional structure. In the figure, ■ is the collector lead, IA is the chip mounting part of the collector lead, 1B is the external lead-out part of the collector lead, IC+, ICz are the tips of the collector leads, 2 is the solder for fixing the chip, 3 is the transistor chip, and 4 is the transistor chip. A base lead, 5 an emitter lead, 6 a base electrode, 7 an emitter electrode, 8.9 a bonding wire, 10 a resin molded body, 11 a bent portion, and 12 an insulating support. ('0) A-A crane cry review α average tolerance threshold b, A-law breaking Akane flash A-Kuai-ma's one-line addition 4-g Kei-ke 3 maki-sai 45 branch rate 1 Ruto's wood meeting 1 Hayabusa 2 times Cb) A-A cut off -9 < 5 A g ° 11 2 b 1 cho 3 lead frame θ sandwiched 2 Go dormitory 3 Garden 5 Garden (b) A-A visit @ diagram No. 6 of the 6th edition

Claims (1)

[Claims] A lead having a chip mounting part on which a semiconductor chip is mounted, an external lead-out part connected to one side of the chip mounting part, and a lead fixed to the opposite end of the chip mounting part. an insulating support, the insulating support, the chip mounting part, and the semiconductor chip are encapsulated in a resin molded body, and the insulating support keeps the lower surface of the chip mounting part a predetermined distance from the lower surface of the resin molded body. 1. A resin-sealed semiconductor device characterized in that the semiconductor devices are separated from each other.