Active solid-state devices (e.g. – transistors – solid-state diode – Housing or package – For plural devices
Patent
1998-02-09
1999-11-16
Clark, Sheila V.
Active solid-state devices (e.g., transistors, solid-state diode
Housing or package
For plural devices
257724, 257679, H01L 2334
Patent
active
059863412
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention relates to a semiconductor device; more specifically, the present invention relates to a semiconductor device particularly preferable for use in extremely thin, inexpensive IC cards with high bending toughness, wireless multi-chip modules and mobile communication terminals.
1. Background Art
As to IC cards, a card with the cross structure shown in FIG. 20 is described in "Data Carrier, II", pages 137 to 194, Japan Industrial Press Corporation, issued Mar. 15, 1991.
In the card, as shown in FIG. 20, thick condenser chip 411 mounted on board 410 is connected through bonding wire 416 to printed wiring board 412 and is then molded with resin 415, and the resulting whole structure is incorporated into center core 413, of which the top and bottom are covered with over-sheet 409, 414.
Furthermore, Japanese Patent Laid-open No. Hei 3-87299 proposes an IC card comprising a thin-thickness chip.
In the card of such conventional type having the structure shown in FIG. 20, elements such as condenser chip 411 are so thick that these elements are weak to stress of bending and are therefore readily broken, disadvantageously.
As to the card proposed by the Japanese Patent Laid-open No. Hei 3-87299, as shown in FIG. 8, the surface and back face of the condenser chip 41 bonded to the thick board 42 are stressed by a stretch or press operation if the board is bent, so that larger stress is applied to the condenser chip 41 (of a thickness of 200 .mu.m). Therefore, the connection between metallized pattern 43 and the condenser chip 41 connected to the pattern 43 fails; or the condenser chip 41 is weak to mechanical stress because of the thin-thickness and is readily broken through the stress. Hence, the reliability thereof is particularly low.
A card of such conventional structure using condenser chip 41 is fabricated by attaching condenser chip 41 onto a readily bendable thin card 42, followed by wire bonding, and therefore, the card is at low reliability because condenser chip 41 is readily broken. Additionally, the number of the process steps for mounting is undesirably large. Accordingly, it has been difficult to reduce the production cost.
2. Disclosure of the Invention
It is an object of the present invention to overcome the problems of the prior art and provide a highly reliable, inexpensive semiconductor device strongly resistant to breakage during bending, particularly a semiconductor device of a thin-thickness type, having functions as an IC card, multi-chip module or mobile communication terminal.
So as to attain the object, in accordance with the present invention, a thin-thickness device or integrated circuit comprising a condenser is mounted on a flexible card board of the same size as that of a card, and the thickness of the condenser, an integrated circuit or a coil and the thickness of the card provided with the condenser, the integrated circuit or the coil are individually fixed at given dimensions.
More specifically, the thickness of the integrated circuit, the condenser or the coil is defined as 110 .mu.m or less, provided that the lower limits of the thickness of the card and the condenser are 50 .mu.m and 0.1 .mu.m, respectively.
By fixing the integrated circuit, the condenser or the coil at such a thin thickness, the integrated circuit, the condenser or the coil becomes strong to the stress of bending. When these are connected to a thin board such as an IC card with a flexible adhesive, a highly reliable IC card strongly to resistant the stress of bending can be produced.
Preferably, the thickness of a semiconductor device, namely the card on completion, is 760 .mu.m or less when the thickness of the integrated circuit, the condenser or the coil is 110 .mu.m or less.
Preferably, the thickness of a semiconductor device, namely the card on completion, is 500 .mu.m or less, when the thickness of the integrated circuit, the condenser or the coil is 19 .mu.m or less. Additionally, the thickness of a semiconductor device, namely the card on completion, is 250 .mu.m
REFERENCES:
patent: 4962415 (1990-10-01), Yamamoto et al.
patent: 5598032 (1997-01-01), Fidalgo
patent: 5719437 (1998-02-01), Clifton et al.
Miyazaki Masaru
Tsubosaki Kunihiro
Usami Mitsuo
Clark Sheila V.
Hitachi , Ltd.
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