HIGH FREQUENCY MULTILAYER CIRCUIT BOARD AND ITS PRODUCTION

摘要

PURPOSE:To make a high frequency multilayer circuit board small in size and light in weight by changing the dielectric thickness of the multilayer circuit board in accordance with a place. CONSTITUTION:The thickness of the dielectric board interposing a signal line or a power source line inside the same board is changed in accordance with the place in the high frequency multilayer circuit board. An opening to be a via-hole 302 is perforated in the substrate 301 to be an uppermost part, at first. Moreover, the opening place 303 where substrate thickness becomes thin is locally perforated. Next, conductive material 304 is buried into the via-hole. An upper part electrode 305 for constituting a strip line is printed on a green sheet to be a intermediate layer. The signal line 306 of the strip line is printed on the green sheet to be the lowermost part so as to be laminated and sintered. Thus, the thickness of the board is made to be thin at the place where the strip line of a low characteristic impedance is necessary in a circuit and the thickness of the board is made to be thick at the place where the strip line of the high characteristic impedance is necessary.