Shin-etsu Polymer Co., Ltd.

Katsuhisa Aizawa

Akio Nakamura

Osami Hayashi

Takumi Suda

The invention provides an efficient method for the preparation of a plastic-made computer-operating card having an emboss-worked relief pattern on the surface by adhesively bonding an emboss-worked plastic-made covering sheet to a body of the card. In the inventive method, a sheet for covering is lined with a second sheet on the back surface and the laminate is emboss-worked so that the debris of the second sheet fills up the cavity formed behind the relief pattern in the first sheet followed by peeling off the undeformed portion of the second sheet leaving the debris filling the cavity. Since the cavity behind the emboss-worked relief pattern is filled up with the debris of the second sheet, the emboss-worked covering sheet is safe from the troubles of collapsing or flattening in the subsequent step of adhesive bonding thereof to the body of the card.

Method for the preparation of an emboss-worked plastic card

The invention relates to an improvement in the so-called flip-chip method for electrically connecting bonding pads of a semiconductor device, e.g., IC chips, and electrodes of a circuit board. In place of the conventional bumps formed of a solder alloy on the bonding pads, the bonding pads in the invention are formed of a material having electric conductivity and rubbery elasticity so that the reliability of the electric connection can greatly be improved.

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Saitama, Japan

Katsuhisa Aizawa