Patent ID: 6579565
Filing Date: 2003-06-17
Classification: H05K,Y10S,Y10T

Abstract:
A method for making a multilayered circuit board comprising:a. forming a multilayered clad sheet with copper layers interposed by a nickel layer to form a sheet comprising first copper layer/first nickel layer/second copper layer/second nickel layer/third copper layer; b. forming a photoresist film on the first copper layer, exposing the photoresist film to light, and developing the photoresist film; c. selectively etching the first copper layer to leave a columnar conductor as the outer copper layer; d. forming a photoresist film on the first nickel layer, exposing and developing the photoresist film, and coating the first nickel layer with resin to form a first insulating layer; e. forming an internal conduction layer by etching the first nickel layer, the second copper layer, and the second nickel layer; f. coating the surface of the internal conduction layer with a resin to form a second insulating layer and polishing the second insulating layer so that the top of the columnar conductor is exposed; g. coating the surface of the resin with copper to form an outer conductor layer; h. patterning the outer conductor layer.