Semiconductor device and fabrication method
AssigneeHitachi, Ltd.
InventorsMitsuo Usami, Takashi Tase
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Abstract
A thin-film semiconductor device comprising at least a semiconductor element and a wiring is disclosed. A thin film of a protective insulating material is formed on the lower surface of the semiconductor element, and a substrate is bonded on the lower surface of the thin film. A method for fabricating the thin-film semi-conductor device is also disclosed, in which a thin-film semiconductor circuit is formed on a silicon-on-insulator wafer, the silicon substrate on the reverse side of the silicon-on-insulator wafer is etched off, a thin-film semiconductor chip is formed and attached to the of substrate, and the thin-film semiconductor chip and the substrate are wired to each other by printing.
Claims26
An IC card including an LSI chip interposed between flexible substrates,
- wherein a critical curvature of said LSI chip is smaller than that of said IC card, and
- wherein a neutral plane of said LSI chip is disposed within ±5% of one-half of the thickness of said IC card from the neutral plane of said IC card.
An IC card including an LSI chip interposed between flexible substrates,
- wherein a critical curvature of said LSI chip is smaller than that of said IC card, and
- wherein said flexible substrates for interposing therebetween said LSI chip are card shaped and have the same width.
A method for fabricating an IC card including an LSI chip interposed between flexible substrates, comprising:
- forming a plurality of LSI chips on a silicon-on-insulator (SOI) wafer;
- eliminating a support substrate made of silicon from a rear side of said SOI wafer to form an LSI chip which has a critical curvature smaller than that of said IC card;
- electrically connecting said LSI chip to wiring formed on a first of said flexible substrates;
- and
- covering said LSI chip with a second of said flexible substrates, wherein a neutral plane of said LSI chip is disposed within ±5% of one-half of the thickness of said IC card from the neutral plane of said IC card.
A method for fabricating an IC card including an LSI chip interposed between a pair of flexible substrates, comprising:
- forming a plurality of LSI chips on a semiconductor wafer;
- eliminating a rear side of said semiconductor wafer to form an LSI chip which has a critical radius of curvature smaller than that of said IC card;
- electrically connecting said LSI chip to wiring formed on a first of said pair of flexible substrates by a conductive ink;
- and
- covering said LSI chip with the second of said pair of flexible substrates, wherein a neutral plane of said LSI chip is disposed within ±5% of one-half of the thickness of said IC card from the neutral plane of said IC card.
A method for fabricating an IC card including an LSI chip interposed between flexible substrates, comprising:
- preparing a flexible LSI chip;
- electrically connecting said LSI chip to wiring formed on a first of said flexible substrates;
- and
- covering said LSI chip with a second of said flexible substrates, wherein a neutral plane of said LSI chip is disposed within ±5% of one-half of the thickness of said IC card from the neutral plane of said IC card.
Dependencies are inferred from the claim text.