US Patent No. 9,883,599

MANUFACTURING METHOD FOR MULTI-LAYER CIRCUIT BOARD HAVING CAVITY


Patent No. 9,883,599
Issue Date January 30, 2018
Title Manufacturing Method For Multi-layer Circuit Board Having Cavity
Inventorship Chien-Hung Wu, Hsinchu County (TW)
Assignee Subtron Technology Co., Ltd., Hsinchu County (TW)

Claim of US Patent No. 9,883,599

1. A manufacturing method of a multi-layer circuit board having a cavity, comprising:
providing a core board and forming a through hole that penetrates the core board, wherein the core board comprises a first
dielectric layer and two first conductive layers that are disposed on two opposite surfaces of the first dielectric layer
and conducted with each other;

forming two build-up structures, the step of forming each of the two build-up structures comprises:
providing at least one second conductive layer;
bonding at least one second dielectric layer to the at least one second conductive layer, and bonding a third conductive layer
to the at least one second dielectric layer; and

patterning the third conductive layer to form a stopper layer that exposes a portion of the at least one second dielectric
layer, wherein the at least one second conductive layer, the at least one second dielectric layer, and the stopper layer constitute
each of the two build-up structures;

bonding the two build-up structures to two opposite sides of the core board and each of the two build-up structures facing
the core board with the stopper layer to form the multi-layer circuit board, the two build-up structures cover the through
hole and the stopper layer corresponding to the through hole, wherein each of the two build-up structures comprises the stopper
layer, the at least one second dielectric layer and the at least one second conductive layer which are stacked in sequence
on the stopper layer; and

removing a portion of one of the two build-up structures corresponding to the through hole, such that the through hole communicates
with the removed portion of the one of the two build-up structures outside, to form the cavity.