JPH0621271A - Semiconductor package structure - Google Patents

Abstract

PURPOSE:To prevent occurrence of package crack by coating the boundary of a mold resin on the rear side of a silicon circuit wiring board with an organic group heat resistant bonding agent. CONSTITUTION:The rear side of a lead frame die pad 4 as well as that of a silicon chip 1 are coated with a polymide group resin 11. By this, the adhesion between the lead frame die pad 4 and a mold resin 8 is promoted. As a result, the occurrence of package cracks at the area from the rear side edge part of the silicon chip 1 to the surface of mold resin 8 and also at the area from the rear side of the lead frame die pad 4 to the surface of the mold resin 8 is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor package structure in a silicon-on-silicon-device transfer mold package.

[0002]

2. Description of the Related Art Recently, a silicon substrate 2 as shown in FIG.
The development of silicon-on-silicon mounting technology in which the silicon chip 1 is flip-chip bonded via the bumps 3 is being actively developed. This silicon on
The silicon packaging technology has features such as easy mounting of large-sized chips, excellent reliability, and easy multi-functionality, large capacity, and high density. That is, silicon
On-silicon packaging technology is a technology that is highly expected as the next-generation high-density packaging technology.

As a packaging method of a silicon-on-silicon device, a transfer mold package form as shown in FIG. 4 is considered as one method. This transfer mold package is formed by the following process. (1) The bump 3 of the silicon chip 1 on the silicon substrate 2
A silicon-on-silicon device connected by flip-chip bonding via the die is bonded onto the lead frame 4. (2) Silicon-on-silicon-The terminal of the device and the lead frame 4 are wire-bonded with the wire 5. (3) The interface resin 7 is injected between the silicon chip 1 and the silicon substrate 2 as needed. (4) Pour the molding resin 8 into the mold and perform transfer molding.

[0004]

However, when a silicon-on-silicon device is packaged by the transfer mold package as described above, the adhesion between the back surface of the silicon chip 1 and the molding resin is generally high. bad. Therefore, in a reliability test such as a temperature cycle test, as shown in FIG. 5, there is a problem that a package crack 9 is likely to occur from the back surface edge portion of the silicon chip 1 to the surface of the mold resin 8.

Therefore, an object of the present invention is to provide a semiconductor package structure which can prevent the occurrence of package cracks and can greatly improve the life.

[0006]

To achieve the above object, the first invention is a transfer of a silicon-on-silicon device in which another silicon circuit wiring board is mounted on the silicon circuit wiring board by flip chip bonding connection. A feature of the molded packaged semiconductor package structure is that an organic heat-resistant adhesive is coated on an interface between the back surface of the silicon circuit wiring board and the molding resin.

A second invention is characterized in that, in the semiconductor package structure of the first invention, the organic heat-resistant adhesive is a polyimide resin.

[0008]

In the first aspect of the present invention, when the silicon-on-silicon device in which another silicon circuit wiring board is mounted on the silicon circuit wiring board by flip-chip bonding connection is transfer mold packaged, the silicon circuit wiring board An organic heat-resistant adhesive is coated on the interface with the mold resin on the back surface. In this way, the adhesion between the back surface of the silicon circuit wiring board and the molding resin is improved.

In the second invention, a polyimide resin is used as the organic heat resistant adhesive, and the adhesion between the back surface of the silicon circuit wiring board and the mold resin is easily and effectively improved. .

[0010]

The present invention will be described in detail below with reference to the embodiments shown in the drawings. In this example, the back surface of a silicon chip of a silicon-on-silicon device is coated with an organic heat-resistant adhesive that promotes adhesion with a mold resin, thereby preventing the occurrence of package cracks. Is.

FIG. 1 shows an example of a semiconductor package structure of this embodiment, and the same parts as those in FIGS. 4 and 5 are designated by the same reference numerals. FIG. 1 shows a transfer mold package product in which the back surface of a silicon chip 1 is coated with the polyimide resin 11 as the organic heat resistant adhesive. The transfer mold package product having such a structure is formed by inserting the process of coating the polyimide resin 11 on the back surface of the silicon chip 1 after the wire bonding process (2) in the conventional transfer mold package process described above. it can.

A temperature cycle test (−65 ° C. 150 ° C.) was actually carried out using the transfer molded package product thus obtained and the package product manufactured by the conventional transfer mold method shown in FIG. As a result, as shown in FIG. 4, when the back surface of the silicon chip 1 was not coated with the polyimide resin, package cracks were generated at 200 cycles, whereas the package product coated with the polyimide resin 11 in the present embodiment was No package crack occurs even after 600 cycles. As a result, by coating the back surface of the silicon chip 1 with the polyimide-based resin 11 which is an organic heat-resistant adhesive, the adhesion between the silicon chip 1 and the mold resin 8 is promoted and the occurrence of package cracks is prevented. It was proved to be done.

FIG. 2 shows a semiconductor package structure in an embodiment different from that of FIG. In this embodiment, not only the back surface of the silicon chip 1 but also the back surface of the lead frame die pad 4 is coated with the polyimide resin 11. By doing so, the adhesion between the lead frame die pad 4 and the mold resin 8 is promoted. Therefore, not only the package crack extending from the back edge portion of the silicon chip 1 to the surface of the mold resin 8
Mold resin 8 from the back surface of the lead frame die pad 4
It is also possible to prevent package cracks on the surface of the.

Therefore, according to this embodiment, a further effect of preventing the occurrence of package cracks is exhibited.

In each of the above-mentioned embodiments, a silicon substrate having one silicon chip 1 mounted on the silicon substrate 2.
On Silicon-I explained the case of the device,
It goes without saying that the same effect can be obtained even with a silicon-on-silicon device having a large number of silicon chips mounted thereon. Needless to say, the organic heat-resistant adhesive in the present invention is not limited to the polyimide resin.

[0016]

As is apparent from the above, the semiconductor package structure of the first invention has the same structure as the mold resin on the back surface of the silicon circuit wiring board when transfer-molding the silicon-on-silicon device. Since the organic heat resistant adhesive is coated on the interface, the adhesion between the back surface of the silicon circuit wiring board and the mold resin is improved. Therefore, according to the present invention,
In a reliability test such as a temperature cycle test, it is possible to prevent the occurrence of package cracks from the back surface edge of the silicon circuit wiring board to the mold resin side, and to greatly improve the life of the silicon circuit wiring board.

Further, in the semiconductor package structure of the second invention, since the polyimide resin is used as the organic heat-resistant adhesive, the adhesion between the back surface of the silicon circuit wiring board and the mold resin can be easily and securely ensured. Can be improved. Therefore, it is possible to provide a semiconductor package structure that prevents the occurrence of package cracks and greatly improves the life of the silicon circuit wiring board.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of a semiconductor package structure of the present invention.

FIG. 2 is a cross-sectional view of an embodiment different from FIG.

FIG. 3 is a cross-sectional view of a silicon-on-silicon device.

FIG. 4 is a sectional view of a conventional silicon-on-silicon-device transfer mold package product.

5 is a cross-sectional view showing an example of a case where a package crack occurs in the transfer mold package product shown in FIG.

[Explanation of symbols]

1 ... Silicon chip, 2 ... Silicon substrate, 3 ... Bump, 4 ... Lead frame, 7 ... Interface resin, 8 ...
Mold resin, 11 ... Polyimide resin.

Claims (2)

[Claims] 1. A semiconductor package structure in which a silicon-on-silicon device in which another silicon circuit wiring board is mounted on the silicon circuit wiring board by flip-chip bonding connection is transfer-mold-packaged. A semiconductor package structure characterized in that an interface with a molding resin is coated with an organic heat-resistant adhesive. 2. The semiconductor package structure according to claim 1, wherein the organic heat-resistant adhesive is a polyimide resin.