The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 26, 1996
Filed:
Jun. 09, 1994
Akimi Miyashita, Toride, JP;
Mutsumasa Fujii, Ibaraki-ken, JP;
Kenichi Takahashi, Nagareyama, JP;
Masami Iwakura, Shimodate, JP;
Makoto Kato, Shimodate, JP;
Hitachi Techno Engineering Co., Ltd., Tokyo, JP;
Abstract
In a hot press according to the present invention, a control panel detects the fact that the viscosity of bonding resin of multilayer circuit board materials is minimized by taking thereinto at least one of the values measured by a speed sensor of a lower bolster, a measuring portion for measuring a control current of an electromagnetic proportional relief valve and a relief amount detector for detecting the relief amount of the electromagnetic proportional relief valve, and gives an instruction of an optimum air pressure addition timing. Accordingly, even if the multilayer circuit board materials and the like are varied, it is always possible to change over from a vacuum condition to an air pressure added condition at the best timing, thereby making it possible to obtain a multilayer circuit board of a uniform thickness without causing generation of void.