摘要 |
PCT No. PCT/US90/06160 Sec. 371 Date Apr. 24, 1992 Sec. 102(e) Date Apr. 24, 1992 PCT Filed Oct. 25, 1990 PCT Pub. No. WO91/07073 PCT Pub. Date May 16, 1991.A method of manufacturing a multilayered circuit board, comprises the steps of: (a) laminating an insulating sheet on a lower layer (2) which reflects a laser light applied through the insulating sheet (4 and 6), said insulating sheet comprising a carrier film (4) and an insulating layer (6) formed on the carrier film; (b) forming via holes (8) in predetermined parts of said insulating sheet by applying a laser light thereto; (c) filling a conductive material (10) in the via holes formed in said insulating sheet; (d) forming a circuit-pattern layer (12) on said insulating layer with the via holes filled with the conductive material; (e) repeating steps (a) to (c) on an uppermost insulating sheet, and repeating steps (a) to (d) until a desired number of circuit-pattern layers are formed below said insulating sheet, in the case where the board has at least two circuit-pattern layers; and (f) firing the layers of the multilayered structure formed in the step (e) at the same time.
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