Circuit board and method for manufacturing the same
AssigneeEcocera Optronics Co., Ltd.
InventorsCheng-Feng Chou, Hung-Pin Lee, Tzu-Yuan Lin
Life of this patent
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Abstract
The invention provides a method for manufacturing a circuit board comprising the steps of: (a) forming a through hole in a substrate; (b) providing a photo resist to cover a predetermined area adjacent to the through hole on a first surface and a second surface opposite to the first surface of the substrate; and (c) performing an etching process to make the through hole has a shape of dumbbell.
Claims18
A method for manufacturing a circuit board, comprising steps of:
- (a) forming a through hole in a substrate having a first surface and a second surface opposite to the first surface, wherein the through hole includes a first part adjacent to the first surface, a second part adjacent to the second surface and a third part located between the first part and the second part;
- (b) providing a photo resist to cover a predetermined area adjacent to the through hole on the first surface and the second surface of the substrate to expose a part of area of the first surface adjacent to the first part and a part of area of the second surface adjacent to the second part;
- and
- (c) performing an etching process to make the diameters of the first part and the second part of the through hole get narrower toward the third part.
The method for manufacturing a circuit board of claim 11, wherein the through hole has a largest diameter of 60-100 μm after step (c).
A circuit board, comprising:
- a substrate having a first surface and a second surface opposite to the first surface;
- and
- a through hole formed in the substrate, wherein the through hole has a diameter getting narrower toward a central part of the through hole from the first and the second surfaces of the substrate, and an inner wall of the through hole has a surface roughness (Ra) of 0.3-0.4 μm.
Dependencies are inferred from the claim text.