Radiation imagery chemistry: process – composition – or product th – Imaging affecting physical property of radiation sensitive... – Radiation sensitive composition or product or process of making
Reexamination Certificate
2000-09-14
2001-12-25
Lam, Cathy (Department: 1775)
Radiation imagery chemistry: process, composition, or product th
Imaging affecting physical property of radiation sensitive...
Radiation sensitive composition or product or process of making
C430S018000, C430S056000, C428S209000
Reexamination Certificate
active
06333136
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a carrier film into which a semiconductor device is suitably mounted at high-density and to a process for producing the same.
2. Description of the Related Art
As a carrier film into which the semiconductor device is mounted, there is a conventionally known carrier film as disclosed in pages 727 to 732 of the 46th Electric Component & Technology Conference, for example.
FIG. 1
is a schematic sectional view showing such a construction. In
FIG. 1
, tape matrix
34
comprising a copper wiring pattern
31
, a base layer
32
made from polyimide film, and a bonding layer
33
made from thermoplastic polyimide film is provided with a bump
35
for electrical connection to a chip, and a cover resist layer
37
having openings
36
for electrical connection to a substrate to be mounted is defined on the copper wiring pattern
31
.
In the carrier film having the above construction, quality of material and forming conditions of the cover resist layer
37
have a great influence on process margin and reliability in assembly of the semiconductor device. Properties required for the cover resist layer
37
are heat resistance, moisture resistance, close-contact property, chemical resistance in a plating process or the like, and smaller contraction in hardening of resin to prevent warping of the carrier film. Furthermore, in order to keep up with refinement of openings
36
due to increased number of pins in the semiconductor device, it is desirable to form the cover resist layer
37
in exactly the same exposure and developing process as those for a normal photoresist.
Epoxy acrylate resin or polyimide resin disclosed in Japanese Patent Application Laid-open No. 6-230571 or Japanese Patent Application Laid-open No. 8-50353, for example, is known as material of the cover resist. However, the conventional epoxy acrylate resin does not have sufficient heat resistance, causing degradation in insulation due to sag of pattern or carbonization in an assembling process of the semiconductor device. Further, the conventional epoxy acrylate resin does not have sufficient moisture resistance and chemical resistance and can not form a reliable semiconductor device. On the other hand, the polyimide resin has sufficient heat resistance of 300° C. or more. However, the polyimide resin contracts largely at the time of hardening to cause warping, and is necessary to be heated at temperature of as high as 300° C. or more for hardening, such heat degrading the bonding layer
33
. For the above reasons, it is very difficult to apply the polyimide resin to the carrier film.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a carrier film in which a cover resist layer is formed on a heat-resistant resin film including a conductive wiring pattern, the cover resist layer having heat resistance, moisture resistance, close contact property, chemical resistance in a plating process or the like, and does not warp because contraction in resin hardening is small.
To achieve the above object of the present invention, there is provided a carrier film in which a cover resist layer made of epoxy acrylate resin including a fluorene skeleton is formed on a heat-resistant resin film including a conductive wiring pattern. Furthermore, the carrier film which is remarkably flexuous and facilitates assembly of a semiconductor device can be obtained by forming the cover resist layer made of the epoxy acrylate resin including the fluorene skeleton by heating at temperature in a range of 180° C. to 260° C. for hardening.
Because the epoxy acrylate resin including the fluorene skeleton used in the present invention has photosensitivity, a through hole can be formed in a photo process like in a case where normal resist material is used. Also, the hardened film has heat resistance of 300° C. or more and contraction of the film is small when hardened, thereby preventing warping of the carrier film.
REFERENCES:
patent: 4684678 (1987-08-01), Schultz et al.
patent: 5153051 (1992-10-01), Dorinski
patent: 5403683 (1995-04-01), Ohta et al.
patent: 5539064 (1996-07-01), Hashimoto et al.
patent: 5700607 (1997-12-01), Rath et al.
patent: 5830563 (1998-11-01), Shimoto et al.
patent: 5889233 (1999-03-01), Shimoto et al.
patent: 61-98725 (1986-05-01), None
patent: 4-292611 (1992-10-01), None
patent: 5-70528 (1993-03-01), None
patent: 6-230571 (1994-08-01), None
patent: 8-50353 (1996-02-01), None
S. Matsuda et al., “Development of Molded Fine-pitch Ball Grid Array (FPBGA) Using Through-Hole Bonding Process”, IEEE Electronics Components and Technology Conference, May 28-31, 1996, pp. 727-732.
Matsui Koji
Shimoto Tadanori
Lam Cathy
NEC Corporation
Sughrue & Mion, PLLC
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