Stock material or miscellaneous articles – Layer or component removable to expose adhesive – Halogen containing compound
Patent
1991-09-20
1994-03-01
Davis, Jenna L.
Stock material or miscellaneous articles
Layer or component removable to expose adhesive
Halogen containing compound
428349, 428355, C09J 702
Patent
active
052906140
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This invention relates to an adhesive tape for tape automated bonding (hereafter referred as TAB). The adhesive tape for TAB is processed into a tape carrier which is used in a process of manufacturing semiconductor devices, in particular, those devices requiring low-dimensional changes to suit high-pin count and fine-patterned devices.
DESCRIPTION OF PRIOR ART
Heretofore, the adhesive tapes for TAB have been processed into tape carriers by the method which comprises the following steps:
(1) punching the adhesive tape for TAB by stamping means to make a sprocket-device hole and removing a protective film from the punched tape;
(2) attaching copper foil on the removed portion of the punched tape by a thermocompression bonder and heating the copper-foil laminated tape to harden the adhesive therein;
(3) coating a photoresist on the copper-foil laminated tape, irradiating UV or the like through a mask to the photoresist, and developing the photoresist with a developer;
(4) backing the device-hole, etching the copper, eliminating the resist, de-backing the device-hole, coating a solder resist on the copper-foil laminated tape, and making a circuit on the copper-foil laminated tape; and
(5) plating tin or gold on the tape to obtain a tape carrier.
A conventional tape carrier obtained by the above steps can be further processed by the steps comprising bonding the semiconductor-chip on the tape by the inner-lead bonder, cutting the outer-lead portion from the chips-bonded tape, and bonding the tape on a printed plate by outer-lead bonder followed by molding in the resin.
Alternatively, the above resulting tape can be processed by steps comprising molding the tape by resin after bonding the tips on the tape by inner-lead bonder, cutting the outer-lead portion and a part of the circuit adjusted to the outer-lead portion, and outer-lead bonding the tape.
However, the above conventional processes have some problems. That is, for example, it is difficult to remove the ionic impurities generated from the adhesive and organic-insulating films in the above processes of preparing the tape carrier. In the above processes, these ionic impurities are often contaminated by the molding resin, the adjacent circuit or the like, especially in the above steps of (3) to (5), and thus the above chip or an AI wire is corroded and the electrical-insulating reliability of the carrier is deteriorated.
The degree of the contamination mainly depends on a composition of the adhesive used for the adhesive tape for TAB. In the above steps of (3) to (5), the ionic impurities are not only generated from the adhesive itself but also from the steps of exposing the adhesive to alkaline (for example, K.sup.+ ion in the gold-plating step or the resist-peeling step) or acidic solution (for example, Cl ion or SH.sub.4 ion in the gold-plating step), etching solution (Cl ion), and the like.
Furthermore, the electrical-insulating reliability does not only depend on the ionic impurities but also depends on the humidity-thermal resistance, the electrical resistance and other properties of the adhesive.
The conventional adhesive used for the adhesive tape for TAB, mainly contains an epoxy resin as a thermosetting composition to improve several properties of the TAB tape, such as the electrical insulating reliability, the chemical resistance, and the thermal resistance thereof. However, the epoxy-type adhesive affects adhesion properties of the adhesive tape for TAB. Thus, the adhesive strength of the adhesive tape for TAB is decreased when the adhesive consists of epoxy resins. If the content of the thermosetting component is lowered, on the other hand, the adhesion property is improved in spite of the other properties mentioned above which are decreasing.
Accordingly, one of the objectives of the present invention is to solve the above problems and is to provide adhesive tape for TAB having improved properties of the electrical insulating reliability, the chemical resistance, the thermal resistance, and the adhesion strength pro
REFERENCES:
Abstract, Database WPIL, Section Ch, Week 8201, Derwent Publications Ltd., Class A05, AN 82-00503E.
Abstract, Database WPIL, Section Ch, Week 8644, Derwent Publications Ltd., Class A04, AN 86-288407.
Koshimura Atsushi
Narushima Hitoshi
Oishi Tadahiro
Tsukamoto Yoshikazu
Davis Jenna L.
Tomoegawa Paper Co. Ltd.
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