Hot press for producing multilayer circuit board
US5578159A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 9, 1994 |
| Grant date | Nov 26, 1996 |
| Priority date | — |
| Expiry date | Jun 9, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K3/4611
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.