JPH05198728A - Semiconductor integrated circuit - Google Patents

Abstract

(57) [Summary] [Object] It is an object of the present invention to provide a semiconductor integrated circuit having a higher density by achieving a thinner package by preventing contact between a bus bar and a bonding wire. A semiconductor integrated circuit according to the present invention includes a bus bar 2 arranged inside an inner lead 1 and an inner lead 1.
And the semiconductor chip 4 fixed to the bus bar 2 via the insulating material 3 and the upper surface of the bus bar 2 are detoured in a loop shape,
A bonding wire 6 connecting the bonding pad 5 of the semiconductor chip 4 and the inner lead 1 through an opening provided inside the bus bar 2 and insulation formed by an insulating adhesive applied to the upper surface of the bus bar 2. The coatings 7 and 7a are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor integrated circuit,
In particular, the present invention relates to a semiconductor integrated circuit in which a bus bar of a lead frame is provided with an insulating film that prevents contact of bonding wires.

[0002]

2. Description of the Related Art In a conventional semiconductor integrated circuit, for example, a tab portion for mounting a semiconductor chip is formed, and inner leads arranged at a predetermined interval so that the leads do not come into contact with each other, and Formed by using a lead frame provided with a bus bar for power supply arranged inside, wire bonding the inner lead and bus bar to the bonding pad of the semiconductor chip, and then molding the lead frame and the semiconductor chip with sealing resin. Has been done.

In recent years, semiconductor integrated circuits have tended to increase in size as the semiconductor chips have become larger and more integrated. For this reason, the tab portion becomes large in order to mount the large-sized semiconductor chip on the lead frame, and it becomes difficult to form a lead frame having inner leads with a predetermined distance from the semiconductor chip. ing.

In order to solve the above-mentioned problem, as shown in FIG. 4, a bus bar 2 is provided inside the inner lead 1, and an insulating material 3 is provided on the inner lead 1 and the bus bar 2.
Semiconductor chip 4 fixed via the
JP-A-59-92556 and JP-A-61-241959 propose a semiconductor integrated circuit which has a bonding wire 5 for connecting the inner pad 1 and the bus bar 2 and is molded with a sealing resin 9. ing. In this semiconductor integrated circuit, as shown in FIG. 5, a bonding wire 6 connecting the inner lead 1 and the bonding pad 5 passes over the bus bar 2.

According to this semiconductor integrated circuit, since the semiconductor chip 4 is adhered and fixed to the inner lead 1 and the bus bar 2, the tab portion can be omitted, so that the contact area between the lead frame and the sealing resin 9 is reduced, and As a result, it is possible to suppress the occurrence of cracks due to the low adhesion between the two and to suppress the size increase of the package due to the size increase of the semiconductor chip 4.

Further, as shown in FIGS. 6 (a) and 6 (b), an insulating coating 7 is formed by applying an insulating adhesive to the upper surface of the bus bar 2 to bond the bonding wire 6 to the bus bar 2. There is a semiconductor integrated circuit in which contact can be prevented and the loop of the bonding wire 6 can be formed low.

[0007]

However, in the conventional semiconductor integrated circuit, since the bus bar is formed inside the inner lead, the bonding wire connecting the semiconductor chip and the inner lead is looped so as not to contact the bus bar. Since the wiring is formed in the same manner, the length of the bonding wire increases, and the height of the bonding wire in the thickness direction increases, which makes it difficult to thin the package of the semiconductor integrated circuit.

Further, as shown in FIGS. 6 (a) and 6 (b), when the height of the loop is reduced, the coating thickness of the insulating coating formed by applying the insulating adhesive is about 10 μm. Since the insulating coating formed by the surface tension acting on the insulating adhesive has a tilt angle of about 10 °, the insulating coating becomes thin at the tip of the tilted portion, that is, at the corner of the bus bar, As a result, there is a problem in that if the insulating property deteriorates and the bonding wire that detours in a loop on the bus bar is deformed, there is a large possibility that the bonding wire electrically contacts the corner portion of the bus bar. Therefore, it is an object of the present invention to provide a semiconductor integrated circuit having a higher density by reducing the thickness of the package by preventing electrical contact between the bus bar and the bonding wire.

[0009]

SUMMARY OF THE INVENTION According to the present invention, a package is made thin by preventing electrical contact between a bus bar and a bonding wire, and a semiconductor integrated circuit having a higher density is provided. Multi-layer insulator of adhesive insulating material that covers the surface, the insulator formed by solidifying the adhesive insulating material applied with the surface of the bus bar oriented in the direction in which gravity acts, or the surface and both sides of the bus bar Provided is a semiconductor integrated circuit having a film-shaped molded insulator covering a surface.

[0010]

According to the semiconductor integrated circuit of the present invention, the multilayer insulator of the adhesive insulating material covering the surface of the bus bar and the adhesive insulating material applied with the surface of the bus bar oriented in the direction in which gravity acts are solidified. An insulator formed by
Alternatively, by having a film-shaped molded insulator that covers the surface and both side surfaces of the bus bar, the bus bar is sufficiently covered and good insulating properties are maintained. In particular, since the insulating coating that effectively covers the corners of the bus bar that are likely to come into contact with the bonding wire is formed, the bonding wire is prevented from coming into contact with the bus bar.

[0011]

First Embodiment A semiconductor integrated circuit of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 shows an embodiment of a semiconductor integrated circuit of the present invention, which includes a bus bar 2 arranged inside an inner lead 1, a semiconductor chip 4 fixed to the inner lead 1 and the bus bar 2 via an insulating material 3, On the upper surface of the bus bar 2 and the bonding wire 6 that bypasses the upper surface of the bus bar 2 in a loop shape and connects the bonding pad 5 of the semiconductor chip 4 to the inner lead 1 through the opening provided inside the bus bar 2. It is composed of insulating coatings 7 and 7a formed by an insulating adhesive applied.

The insulating adhesive used for coating the bus bar 2 is, for example, polyamide imide diluted with a solvent, and the first insulating layer is applied to the upper surface of the bus bar 2 by a dispenser (not shown). After applying the adhesive, heat treatment is performed at 150 ° C. for 1 minute and drying is performed to remove the solvent and form the insulating coating 7. On the formed insulating coating 7, the insulating coating 7a is laminated on the insulating coating 7 by further applying the second insulating adhesive and performing a final heat treatment at 150 ° C. for 2 minutes. It is formed.

By forming the insulating coatings 7 and 7a made of an insulating adhesive on the surface of the bus bar 2 by the above-described method, the film thickness of the insulating adhesive formed on the surface of the bus bar 2 is 20 μm. It can be formed with the above thickness, and as a result, the corner portion of the bus bar 2 is sufficiently covered with the insulating adhesive, so that even if the bonding wire 6 is deformed, the bonding to the corner portion of the bus bar 2 is performed. The contact of the wire 6 can be prevented.

[0014]

[Embodiment 2] FIG. 2 shows another embodiment of the semiconductor integrated circuit of the present invention, in which the bus bar 2 formed inside the inner lead 1 is predetermined by a needle 8 of a dispenser located below the bus bar 2. An insulating adhesive having a viscosity of is extruded and applied. As this insulating adhesive, an insulating adhesive having a higher viscosity than the insulating adhesive used in Example 1 is used. The other configuration is the same as that of the first embodiment, and the description is omitted.

By applying the insulating adhesive from the lower side of the bus bar 2, the insulating adhesive adheres to the lower surface of the bus bar 2. The applied insulating adhesive is dried in a shape that hangs down in the dropping direction by the action of surface tension and gravity, and the insulating coating 70 is formed. Therefore, the insulating coating 70 is formed thick by one application of the insulating adhesive, and the inclination angle of the insulating coating 70 is 30 ° at the corner of the bus bar 2.
As described above, it is possible to prevent the bonding wire 6 from coming into contact with the corner of the bus bar 2.

[0016]

[Embodiment 3] FIG. 3 shows another embodiment of the semiconductor integrated circuit of the present invention. An insulating member 71 is fixed to the bus bar 2 formed inside the inner lead 1 so as to surround the bus bar 2.
Is formed, and the periphery is molded with the sealing resin 9. The other configuration is the same as that of the first embodiment, and the description is omitted.

The insulating member 71 is, for example, an insulating film such as a polyimide film, and an insulating film having a U-shaped or U-shaped cross section is adhered and fixed to the bus bar 2. It is desirable that this insulating film has adhesiveness or tackiness on the surface. The shape of the insulating film is not limited to the U-shape and the U-shape,
It may be formed in a shape covering the entire surface of the bus bar 2 and a side surface of the bus bar 2, or a shape covering the entire upper surface of the bus bar 2 and a part of the side surface thereof. An insulating film may be adhered and fixed to the edge portion of the bus bar 2 which is easy to use.

In addition, the opening for wire bonding between the semiconductor chip 4 and the bus bar 2 is provided with an insulating film 71.
It may be provided at a predetermined position.

By forming the insulating coating of the above-mentioned insulating film on the bus bar 2, the insulating member 71 can be easily formed on the upper surface and the corners of the bus bar 2 where the bonding wires 6 easily come into contact. In addition, since the bonding wire 6 can be attached and fixed to the surface of the insulating film by the adhesiveness or adhesiveness of the surface of the insulating film, it is possible to prevent the bonding wires 6 from contacting each other.

[0020]

As described above, according to the semiconductor integrated circuit of the present invention, the multilayer insulator of the adhesive insulating material for covering the surface of the bus bar and the surface of the bus bar are applied with the surface thereof oriented in the direction in which gravity acts. Prevents electrical contact between the busbar and the bonding wire because it has an insulator formed by solidifying the adhesive insulating material or a film-shaped molded insulator that covers the surface and both sides of the busbar. As a result, the package can be made thinner, and a higher density semiconductor integrated circuit can be provided.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a semiconductor integrated circuit showing an embodiment of the present invention.

FIG. 2 is a sectional view of a semiconductor integrated circuit showing another embodiment of the present invention.

FIG. 3 is a sectional view of a semiconductor integrated circuit showing another embodiment of the present invention.

FIG. 4 is a sectional view showing a conventional semiconductor integrated circuit.

FIG. 5 is an explanatory diagram showing a conventional semiconductor integrated circuit.

FIG. 6 is a sectional view showing a conventional semiconductor integrated circuit.

[Explanation of symbols]

1 Inner Lead 2 Bus Bar 3 Insulating Material 4 Semiconductor Chip 5 Bonding Pad 6 Bonding Wire 7, 7a, 70 Insulating Film 8 Needle 9 Sealing Resin 71 Insulating Film

Front Page Continuation (72) Inventor Go Miyagawa 3550 Kidayomachi, Tsuchiura City, Ibaraki Prefecture Inside Hitachi Cable's System Materials Research Center

Claims (3)

[Claims] 1. A semiconductor chip is fixed to an inner lead of a lead frame and a bus bar via an insulator, the inner lead and the bus bar are connected to the semiconductor chip via a bonding wire, and the bonding wire of the inner lead is formed. In the semiconductor integrated circuit having a configuration in which is passing over the bus bar, the bus bar has a surface covered with a multi-layer insulator of an adhesive insulating material, and is configured so as not to make electrical contact with the bonding wire of the inner lead. A semiconductor integrated circuit characterized by being provided. 2. A semiconductor chip is fixed to an inner lead of a lead frame and a bus bar via an insulator, the inner lead and the bus bar are connected to the semiconductor chip via a bonding wire, and the bonding wire of the inner lead is formed. In the semiconductor integrated circuit having a configuration in which the busbar is passing over the busbar, the busbar is an insulator that is solidified by applying an adhesive insulating material in a state in which the surface thereof is oriented in the direction in which gravity acts, A semiconductor integrated circuit characterized in that the surface is covered so as not to make electrical contact with the bonding wire of the inner lead. 3. A semiconductor chip is fixed to an inner lead of a lead frame and a bus bar via an insulator, the inner lead and the bus bar are connected to the semiconductor chip via a bonding wire, and the bonding wire of the inner lead is formed. In the semiconductor integrated circuit having a structure in which the bus bar passes over the bus bar, the bus bar is covered on its surface and both side surfaces with a film-shaped molding insulating material so as not to make electrical contact with the bonding wire of the inner lead. A semiconductor integrated circuit having a structure.