Abstract: In the present semiconductor device, a chip with an LSI circuit is secured to a board 3 (with the chip flipped) so as to be level. The LSI circuit on the chip is specified to operate normally only when the chip is level. Further, the back of the chip is processed so as to give stress to the chip. The chip has a reduced thickness of 50 &mgr;m or less (alternatively 30 &mgr;m to 50 &mgr;m). Therefore, when the chip is detached from the board, it deforms and is no longer level due to the stress, which prohibits the LSI circuit from operating normally. This way, the present semiconductor device ensures that no analysis can be conducted on the LSI circuit once the chip is detached.

Abstract: A semiconductor device includes, on a protective film laminated on a circuit principal part, (i) a light blocking film provided so as to cover the circuit principal part, (ii) an aluminum oxide film provided so as to completely cover the light blocking film, and (iii) a light-blocking upper wiring provided on the aluminum oxide film. An attempt to exfoliate the light blocking film or the light blocking upper wiring causes the resistance-detection-use upper wiring to break or thin, thereby resulting in an increase in the resistance of the resistance-detection-use wiring. The increase in the resistance is detected by the resistance detecting circuit part, and malfunction or inoperativeness of the circuit principal part is caused in response of detection. By so doing, the circuit principal part can be protected from analysis.

Abstract: A semiconductor device in accordance with the present invention includes a semiconductor element chip pressed and secured on a distortion die-pad so that the semiconductor element chip, sealed inside a package, is held in a predetermined distorted state. The predetermined distorted state is preferably downward or upward warping. The semiconductor element chip operates normally in the distorted state, and does not operate normally when the semiconductor element chip is separated from the semiconductor device, and thereby released from the distortion and laid alone. This ensures that the semiconductor element chip is protected from circuit analysis.

Abstract: An authentication token includes a personal collation unit and communication unit. The personal collation unit includes a sensor, storage unit, and collation unit. The sensor detects biometrical information of a user and outputs the detection result as sensing data. The storage unit stores in advance registered data to be collated with the biometrical information of the user. The collation unit collates the registered data with the sensing data and outputs the collation result as authentication data. The communication unit transmits the authentication data from the personal collation unit to the use device as communication data. The personal collation unit and communication unit are integrated.

Abstract: After a reinforcing plate is bonded to the lower surface of a semiconductor substrate having a major surface on which integrated circuits are formed, the reinforcing plate is cut in units of integrated circuit chips. A reinforcing member is formed from the reinforcing plate bonded to the lower surface of each integrated circuit chip.

Abstract: In the present semiconductor device, a chip with an LSI circuit is secured to a board 3 (with the chip flipped) so as to be level. The LSI circuit on the chip is specified to operate normally only when the chip is level. Further, the back of the chip is processed so as to give stress to the chip. The chip has a reduced thickness of 50 &mgr;m or less (alternatively 30 &mgr;m to 50 &mgr;m). Therefore, when the chip is detached from the board, it deforms and is no longer level due to the stress, which prohibits the LSI circuit from operating normally. This way, the present semiconductor device ensures that no analysis can be conducted on the LSI circuit once the chip is detached.