| 摘要 |
1478570 Stabilizing resin-impregnated laminates INTERNATIONAL BUSINESS MACHINES CORP 23 May 1975 [16 Sept 1974] 22925/75 Heading B5N [Also in Division H1] The dimensional stability of a resin-impregnated laminate is improved by braking to remove moisture, exposing to a moisture-containing ambient atmosphere to cause absorption of moisture, and rebaking to again remove moisture. The laminate may be a printed circuit board in which a metallizing layer on a base of one or more epoxy or polyimide-woven glass cloth prepregs has been removed except at the border region; on air-drying and storage at 60- 100‹ F. and 20-80% RH the laminate expands; it is then stabilized by carrying out the treatment of the invention. The baking and rebaking may be at 150-250‹ F. for 10-30 minutes and the intermediate exposure may be for 1-24 hours at 60-100‹ F. and 20-100% RH. |
