| 摘要 |
A process is described for the manufacture of a void-free multi-layer printed circuit board (PCB). The process includes the steps of, first, laminating one or both sides of a PCB provided with circuitry details, to a cast thermosetting resin layer comprising essentially a B-staged, resin system solid at room temperatures but having a resin flow, under standard curing conditions, greater than a prepreg layer containing glass cloth impregnated by the B-staged resin system. The initial laminating step proceeds at temperatures and/or times substantially below curing conditions to form a prefilled PCB laminate wherein said cast thermosetting resin layer remains B-staged and which is very low in voids. Secondly, one or more of the prefilled PCB laminates are assembled between prepreg layers, each prepreg layer comprising glass cloth impregnated by a second B-staged thermosetting resin compatible with, or the same as, said B-staged thermosetting resin of said cast thermosetting resin layer. Finally, the prefilled PCB laminates and the prepreg layers are laminated (along with other PCB layers, perhaps) under curing conditions, to insure the formation of a void-free multi-layer PCB. The invention is also directed to the article of manufacture made by the process.
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