JPH0617249U - Semiconductor device - Google Patents

Abstract

(57) [Abstract] [Purpose] Conducting the conduction of heat from the semiconductor chip to the heat sink,
Improves the electrical insulation between the semiconductor chip and the heat sink without lowering the electrical insulation. [Structure] A heat sink member 1 including a heat sink 1a and an insulating layer 1b is prepared. A chip connecting conductive member 2 to which a semiconductor chip 3 is fixed is prepared. The chip connecting conductive member 2 is fixed onto the insulating layer 1b of the heat sink member 1. Recesses 8 and 9 are provided in the conductive member 2 for chip connection so as to face the peripheral edge of the heat sink member 1 to enhance the insulating property here.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a semiconductor device such as a transistor and an integrated circuit device with a heat sink.

[0002]

[Problems to be solved by conventional techniques and devices]

 It is equipped with a lead frame to which a semiconductor chip is fixed, and a heat sink electrically insulated from the lead frame. A part of the resin encapsulant covering the lead frame is interposed between the lead frame and the heat sink, and both There is an insulated power semiconductor device that achieves electrical insulation. In the semiconductor device with the above structure, a heat sink without an insulating layer is placed in close contact with the bottom of the molding cavity (cavity) of the resin molding die (transfer molding die), and the lead frame is placed from the top of this heat sink. The resin for sealing is obtained by injecting the resin for sealing into the cavity in a state where the resin is spaced and positioned. Here, the distance between the heat sink and the lead frame must be set to at least 0.5 mm or more so that the sealing resin can be filled well between them and the electrical insulation between them can be kept good. As a result, the resin layer interposed between the heat sink and the lead frame was relatively thick, and the heat dissipation effect was not sufficiently large.

Therefore, the present invention is a semiconductor that can improve the electrical insulation between the heat sink (heat dissipation plate) and the conductive member for connecting the semiconductor chip and the thermal conductivity from the conductive member to the heat sink. The purpose is to provide a device.

[0004]

[Means for Solving the Problems]

 The present invention for achieving the above object provides a conductive heat sink, an insulating layer formed on one main surface of the heat sink, and a semiconductor chip connecting conductive layer fixed on the insulating layer. In a semiconductor device including a conductive member and a semiconductor chip fixed on the conductive member, a dent (recess) may be provided in a region of the conductive member that faces a peripheral edge of the heat dissipation plate. It relates to a characteristic semiconductor device.

[0005]

[Operation and effect of the device]

 The conductive member for connecting a semiconductor chip according to the present invention comprises, for example, a support plate portion and a lead portion of the semiconductor chip, and is used for electrical connection of the semiconductor chip. The recess provided in the chip-connecting conductive member increases the distance between the peripheral edge of the heat dissipation plate and the chip-connecting conductive member to improve electrical insulation. Therefore, even when the heat dissipation is improved by forming the insulating layer on the heat dissipation plate thin, good electrical insulation between the conductive member for chip connection and the heat dissipation plate can be maintained.

[0006]

【Example】

 Next, a semiconductor device according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a power semiconductor device in which the resin encapsulant is removed and some of the leads are notched, and FIG. 2 shows a cross section corresponding to line AA in FIG. As is particularly apparent from FIG. 2, this power semiconductor device includes a heat sink member 1, a chip connecting conductive member 2 formed on the basis of a lead frame, a plurality of transistor chips and IC chips. The semiconductor chip 3 and the resin sealing body 4 are provided.

As shown in FIG. 2, the heat sink member 1 includes a metal heat sink 1a having a thickness of about 2.0 mm and an epoxy having a thickness of about 100 μm formed on the entire upper surface of the heat sink 1a with a uniform thickness. It has a resin-coated insulating layer 1b and a plurality of conductor layers 1c formed in an island shape on the insulating layer 1b and having a thickness of about 30 μm. Further, a hole 1d penetrating the heat dissipation plate 1a and the insulating layer 1b is provided at the corner of one side. The heat sink member 1 is formed by punching out a large-area heat sink forming plate material on which the insulating layer 1b and the conductor layer 1c are formed into an area for one piece. At the time of punching, since the heat radiating plate 1a is punched toward the upper surface by applying a blade from the side (lower surface) where the insulating layer 1b is not formed, a burr 1e is formed on the edge of the upper surface of the heat sink member 1. In FIG. 1, the upper surface of the burr 1e is also covered with the insulating layer 1b, but the insulating layer 1b may peel off at the edge portion during punching. If the heat sink forming plate material is punched from the insulating layer 1b side, cracks are likely to occur in the insulating layer 1b, which is not desirable.

As shown in FIG. 3, the chip-connecting conductive member 2 includes a plurality of support plates 2a for mounting chips, a number of external leads 2b juxtaposed in the arrangement direction of the support plates 2a, and a central side. It has a wiring portion 2c connected to two external leads 2b and its thickness is about 0. It is 5 mm. In FIG. 3, the conductive member 2 for chip connection for one semiconductor device is shown separated from the lead frame, but before this separation, a large number of leads 2b are shown in broken lines. And a plurality of wiring portions 2c are also connected to each other via a two-pronged connecting portion 2d extending from the wiring portion 2c by a strip 7 shown by a broken line.

In the lower surface side region of the chip connecting conductive member 2 corresponding to the peripheral edge of the heat sink member 1, recessed portions, that is, recessed portions 8 and 9 are formed as shown by dotted lines in FIG. 1 and solid lines in FIGS. 2 and 3. Has been done. The recesses 8 and 9 were formed at the same time by press working when forming the lead frame, and have a depth of about 0.25 mm. The holes 10 of the wiring portion 2c shown in FIG. 3 assist the flow of resin during transfer molding.

As shown in FIG. 2, the chip connecting conductive member 2 is positioned so that the recesses 8 and 9 thereof face one long side and the other long side of the heat sink member 1 of FIG. 4, respectively, The support plate 2a and the wiring portion 2c are fixed to the conductor layer 1c of the heat sink member 1 via the solder 11 having a thickness of about 30 μm. Further, the semiconductor chip 3 is fixed to the support plate 2a via the solder 11, and the semiconductor chip 3 is electrically connected to the leads 2b and the like via the fine lead wires 13 as shown in FIG. The chips 3 and the lead thin wires 13 may be formed before or after the conductive member 2 for chip connection is fixed to the heat sink 1.

As shown in FIG. 2, the resin sealing body 4 covers the chip connecting conductive member 2 and the heat sink 1 so as to include the semiconductor chip 3 and the lead thin wires 13. The resin sealing body 4 is formed by a well-known transfer molding method. That is, the semiconductor chip 3 is fixed to the conductive member 2 for chip connection made of a blade frame, the fine lead wires 13 are provided, and the assembly of FIG. 1 to which the heat sink member 1 is fixed is placed in a molding die. It is formed by pressing and injecting fluidized resin into a molding cavity (cavity) corresponding to the resin sealing body 4 and curing it. The strips 5, 6 and 7 are removed after the resin sealing body 4 is formed. Here, the concave portion 8 is arranged inside the resin sealing body 4 so that the strength of the lead 2b can be obtained sufficiently, but the concave portion 9 is cut and removed by the concave portion 9 when the strip 7 is removed. Therefore, a part of it is exposed from the resin sealing body 4 as shown in FIG.

According to the above-mentioned structure, the withstand voltage of the peripheral edge of the heat sink member 1 can be increased even if the insulating layer 1b is thin. Therefore, the thermal conductivity from the chip-connecting conductive member 2 to the heat sink 1a can be improved. Further, since the surface of the heat dissipation plate 1a on which burrs are generated can be on the upper side and the side without burrs can be on the lower side, when the heat dissipation plate 1a is attached to another heat dissipating body, the close contact between them is improved. Further, since the recesses 8 and 9 are formed in the chip connecting conductive member 2 so as to face the edge of the heat sink member 1, even if the burrs 1e are generated in the heat sink member 1 as shown in FIG. The electrical insulation between the conductive member for connection 2 can be kept good.

[0013]

[Modification]

 The present invention is not limited to the above-mentioned embodiments, and the following modifications are possible, for example. (1) The chip connecting conductive member 2 can be fixed to the insulating layer 1b without providing the conductive layer 1c. (2) The present invention can be applied to a semiconductor device including only a transistor chip or an integrated circuit chip. (3) It is desirable to provide the resin sealing body 4, but the present invention can be applied to those that do not have this.

[Brief description of drawings]

FIG. 1 is a plan view showing a semiconductor device of an embodiment of the present invention with a resin sealing body removed.

FIG. 2 is a sectional view showing a semiconductor device of an example at a portion corresponding to line AA in FIG.

FIG. 3 is a bottom view showing the conductive member for chip connection of FIG. 1 in a lead frame state.

FIG. 4 is a plan view of the heat sink member of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat sink member 1a Heat sink 1b Insulating layer 1c Conductive layer 1e Burr 2 Chip connecting conductive member 3 Semiconductor chip

Claims (1)

[Scope of utility model registration request] 1. A conductive heat sink, an insulating layer formed on one main surface of the heat sink, a semiconductor chip connecting conductive member fixed on the insulating layer, and the conductive layer. A semiconductor device comprising a semiconductor chip fixed on a member, wherein a recess is provided in a region of the conductive member facing the periphery of the heat dissipation plate.