Method of fabricating a solder pad structure
AssigneeUnimicron Technology Corp.
InventorsTzyy-Jang Tseng, Shu-Sheng Chiang
Life of this patent
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Abstract
A method for fabricating a solder pad structure. A circuit board having thereon at least one copper pad is provided. A solder resist is formed on the circuit board and covers the copper pad. A solder resist opening, which exposes a portion of the copper pad, is formed in the solder resist by laser. The laser also creates a laser activated layer on sidewalls of the solder resist opening. A chemical copper layer is then grown from the exposed copper pad and concurrently from the laser activated layer.
Claims17
A method for fabricating a solder pad structure of a circuit board, comprising:
- providing a circuit board having thereon at least one copper pad structure;
- forming a solder resist layer on a surface of the circuit board;
- subjecting the solder resist layer to a laser to thereby form a solder resist opening exposing a portion of the copper pad structure, the laser simultaneously forming a laser-activated layer on sidewall of the solder resist opening;
- and
- growing copper from the laser-activated layer on sidewall of the solder resist opening and from the exposed portion of the copper pad structure, wherein the copper is not formed on a top surface of the solder resist layer.
A method for fabricating a solder pad structure of a circuit board, comprising:
- providing a circuit board having thereon at least one copper pad structure;
- forming a solder resist layer on a surface of the circuit board;
- forming a peelable film on the solder resist layer;
- subjecting the peelable film and the solder resist layer to a laser to thereby form a solder resist opening exposing a portion of the copper pad structure;
- forming a seed layer on interior sidewall of the solder resist opening;
- peeling off the peelable film from the solder resist layer;
- and
- filling the solder resist opening with copper.
A method for fabricating a solder pad structure of a circuit board, comprising:
- providing a circuit board having thereon at least one copper pad structure;
- forming a solder resist layer on a surface of the circuit board;
- forming a protective layer on the solder resist layer;
- forming a solder resist opening in the protective layer and the solder resist layer to expose a portion of the copper pad structure;
- selectively forming a seed layer on interior surface of the solder resist opening,
- wherein the seed layer is not formed on a top surface of the protective layer;
- and
- filling the solder resist opening with copper.
Dependencies are inferred from the claim text.