Abstract: In a process producing a multi-layer printed wiring board, an inner core having at least one wiring pattern on its surface and an outer layer of copper foil are laminated with an organic insulating layer interposed therebetween, a via hole is formed using a laser beam, and the outer copper foil and the inner wiring patterns are electrically connected to each other by depositing copper. The process is characterized in that the outer layer of copper foil has a thickness of no more than one-fifth of the thickness of the inner wiring pattern, but will not exceed 7 &mgr;m, preferably 4 &mgr;m. The hole is formed in both the copper foil and the insulating layer simultaneously by irradiating with a laser beam on the outer layer of copper foil.

Abstract: This invention provides a composite foil comprising an aluminum carrier layer and an ultra-thin copper foil having a protective layer disposed between them comprising a porous copper layer and an interpenetrating zinc layer. A process for producing such composite foils comprises the steps of preparing the surface of the aluminum carrier, electrodepositing a porous copper layer on the aluminum carrier layer followed by electrodepositing a zinc layer, and then electrodepositing two layers of copper to form the ultra-thin copper foil. The composite foil provides a uniform bond strength between the aluminum carrier and the protective layer which is adequate to prevent separation of the carrier and ultra-thin copper foil during handling and lamination, but which is significantly lower than the peel strength of a copper/substrate bond, so that the carrier can easily be removed after lamination of the composite foil to an insulating substrate.

Abstract: A digital signal reproduction device including a data strobe circuit high in margin against noise and rapid in recovery from dropout of data and a digital signal reproduction method performed in such device. The digital signal reproduction device includes a pair of data strobe circuits and a switching circuit for selecting one of the outputs of the pair of data strobe circuits, and a circuit for generating from the received signal a signal to control the switching circuit. The data strobe circuits ensure high reliability of the received signal against noise and a short time from dropout of the received signal to acquisition of a reproduction clock. The data strobe circuit is selectable which is suitable for the reproduction state of the reproduced signal.

Abstract: An apparatus for recording and reproducing a video signal and a PCM audio data sampled by a sampling frequency being asynchronous to a field frequency of a video signal. The apparatus enables to record and reproduce the digital data formatted at each field. The apparatus includes an address control circuit for switching the number of sample values to be recorded per field and a clock generating circuit. The clock generating circuit provides a VCO for forcibly stopping the switching of the number of the sample values, keeping the number of the sample values constant and generating a sampling clock being synchronous to a field frequency, based on a signal sent from an input terminal for a selecting signal. When recording a different digital data from the PCM audio data, the sampling clock sent from the clock generating circuit is used in the address control circuit.