| 摘要 |
<p>PURPOSE:To prevent a noise crosstalk caused by interference with signal lines by composing a multilayer board of a board of an interior made of a material having a large thickness and low permittivity, and boards of exteriors made of a material having a small thickness and high permittivity to be disposed therebetween. CONSTITUTION:The thickness of an insulating board 11A is considerably increased as compared with those of first and second boards 12A, 13A. The insulating board 11A is made of triazine having low permittivity, and the first and second boards 12A, 13A are made of epoxy having high permittivity. Such boards are formed as below. First and second inner layer conductor circuit networks 16, 17 are formed on a glass-epoxy copper-plated laminated board by a normal subtractive method, and a glass-polyimide prepreg is adhered thereby by a pressing method to form an electronic circuit board 50A. A first through hole 18 for conducting the patterns of the first and second inner layer conductor circuit networks 16, 17 is formed in the board 50A. Further, in addition to the mutual conduction, a second through hole 19 for inserting a power source, conductor pins is formed.</p> |
