Hitachi Cable, Inc.

Toyoharu Koizumi

Takashi Sato

Akiji Shibata

Norihiro Ashizuka

Tsuyoshi Ishihara

Akifumi Higuchi

The amount of time required to manufacture double-sided printed circuit boards that contain conductor bridges can be reduced. A method is provided which includes the steps of forming holes which pass through an insulating board and a first conductor layer formed on a first main side of the insulating board, bonding a second conductor layer to a second main side of the insulating board having the holes, forming a third conductor layer on the whole first main side of the insulating board after bonding the second conductor layer, masking preset holes with a plating resist, plating the first conductor and holes in the insulating board, patterning the first conductor layer to form a first conductor pattern, patterning said second conductor layer to form a second conductor pattern, and removing the plating resist and the third conductor layer from an area which is covered with the plating resist.

Method for manufacturing printed circuit boards

In a BGA type semiconductor device wherein, while leaving a via hole for a solder ball, an insulating film formed of a photosolder resist (PSR) is provided on a tape substrate on its side where a wiring pattern is provided, a groove portion is provided between a bonding wire sealing portion and the via hole for a solder ball. The groove portion is a smaller-thickness portion of the insulating film provided as a part of the insulating film. By virtue of this construction, at the time of sealing of a wire bonding connection with a mold resin, the flow of the mold resin into the via hole for a solder ball can be prevented.

Growing community of inventors

Kitaibaraki, Japan

Toyoharu Koizumi