Method of molding resin to seal electronic parts using two evacuation steps
US5603879A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 18, 1994 |
| Grant date | Feb 18, 1997 |
| Priority date | — |
| Expiry date | Apr 18, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S425/812
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
In a method of molding resin to seal electronic parts, an internal die space defined at least by pots, cull portions, resin passages and cavities when an upper mold section and a lower mold section are closed, is cut off or sealed from the exterior atmosphere. Thereupon the die space is evacuated using a first evacuation by a vacuum source and a second or instantaneous evacuation by an instantaneous evacuation mechanism. The vacuum source for the first evacuation may be an active vacuum pump, while the instantaneous evacuation mechanism may be a vacuum tank that has been previously pumped down, for example. According to this method, it is possible to quickly improve the degree of vacuum in the internal die space by efficiently and reliably discharging air, moisture and gas from the internal die space to the exterior due to a synergistic action of the evacuation and the instantaneous evacuation. Consequently, the formation of voids in resin molded members is prevented.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.