Method for manufacturing microthrough-hole in circuit board and circuit board structure with microthrough-hole

摘要

A method for manufacturing microthrough-hole includes electroplating a metal layer on a carrier plate, patterning the metal layer to form a first circuit having copper pads, covering the first circuit with a photoresist layer and not covering the copper window between two of the copper pads, etching the metal layer beneath the copper window and removing the photoresist layer, sequentially forming an insulation layer and a second circuit on the first circuit and the copper window, the second circuit layer having a stop pad corresponding to the copper window, removing the carrier plate, upward drilling through the insulation layer between the stop pad and the copper window to form a microthrough-hole beneath the stop pad, and forming a conductive layer in the microthrough-hole to form the microthrough-hole connecting the first and second circuits. The microthrough-hole and its occupied area is greatly reduced, thereby achieving high circuit density.

主权项

1. A method for manufacturing microthrough-hole in circuit board, comprising:
preparing a carrier plate; electroplating a metal layer on the carrier plate; forming a first circuit with a plurality of copper pads on one surface of the metal layer; covering the first circuit with a photoresist layer, wherein a copper window between two of the copper pads is not covered; etching the metal layer beneath the copper window until the carrier plate is exposed and removing the photoresist layer; sequentially forming an insulation layer and a second circuit on the first circuit and the copper windows, the second circuit layer having a stop pad corresponding to the copper window; removing the carrier plate; employing a drilling process to upward drill through the insulation layer corresponding to the copper window and stop at the stop pad so as to form a microthrough-hole beneath the stop pad; and forming a conductive layer in the microthrough-hole to electrically connect the first circuit and the second circuit.