# US 7,608,929 B2 · Electrical connector structure of circuit board and method for fabricating the same

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- Number: US 7,608,929 B2
- Document ID: US7608929B2
- Status: Granted
- Kind: B2
- Application number: 11/370,532
- Filed: 2006-03-08
- Published: 2006-09-14
- Granted: 2009-10-27
- Earliest claimed: 2005-03-09
- Assignees: Phoenix Precision Technology Corporation
- Inventors: Wen-Hung Hu
- Web page: https://patentgrep.com/patent/US7608929B2

## CPC

- H05K 3/243: {characterised by selective plating, e.g. for finish plating of pads (selective plating for making the circuit pattern H05K3/108, H05K3/182)}
- C23C 26/00: Coating not provided for in groups C23C2/00 - C23C24/00
- C23C 28/00: Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
- C23C 28/021: {including at least one metal alloy layer}
- C23C 28/023: {only coatings of metal elements only}
- C25D 5/02: Electroplating of selected surface areas
- H05K 1/111: {Pads for surface mounting, e.g. lay-out}
- H05K 3/108: {by semi-additive methods; masks therefor (characterised by metallic etch mask H05K3/062; electroplating methods or apparatus H05K3/241)}
- H05K 3/28: Applying non-metallic protective coatings {(H05K3/0091 takes precedence; methods for intermediate insulating layers for build-up multilayer circuits H05K3/4673)}
- H05K 3/388: {by the use of a metallic or inorganic thin film adhesion layer}
- H05K 3/4007: {Surface contacts, e.g. bumps (H05K3/4092 takes precedence; deposition of finish layers on pads H05K3/24; forming solder bumps H05K3/3465)}
- H05K 2203/0571: Dual purpose resist, e.g. etch resist used as solder resist, solder resist used as plating resist
- H05K 2203/0574: Stacked resist layers used for different processes
- H05K 2203/0577: Double layer of resist having the same pattern
- H05K 2203/0597: Resist applied over the edges or sides of conductors, e.g. for protection during etching or plating
- Y10T 428/24917: including metal layer
- H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04)
- C25D: PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

An electrical connector structure of circuit board and a method for fabricating the same are proposed. A circuit board having a conductive layer is formed with a first resist layer and a second resist layer thereon, so as to form electrical connection pads and metal bumps on the electrical connection pads. The first and second resist layers are formed with openings therein at positions corresponding to the electrical connection pads and metal bumps, and the exposed conductive layer is removed. An adhesive layer is formed to cover the exposed surfaces of the electrical connection pads and the metal bumps. Then, the second resist layer, the first resist layer and the conductive layer covered by the first resist layer are removed. Later, an insulating protective layer is formed on a surface of the circuit board, and thinned to expose a portion of the adhesive layer, such that electrical connectors of the circuit board are fabricated.

## Claims

### Claim 1

An electrical connector structure of a circuit board, comprising:
an electrical connection pad formed on an insulating layer of the circuit board;
a conductive layer formed between the electrical connection pad and the insulating layer;
a metal bump formed on the electrical connection pad;
an adhesive layer for covering the conductive layer, the electrical connection pad and the metal bump; and
an insulating protective layer formed on the circuit board, wherein a portion of the adhesive layer corresponding to the metal bump is exposed from the insulating protective layer.

### Claim 2 (depends on 1)

The electrical connector structure of a circuit board of claim 1, wherein the insulating protective layer is a solder mask.

### Claim 3 (depends on 1)

The electrical connector structure of a circuit board of claim 1, wherein the metal bump is made of a material selected from the group consisting of copper (Cu), tin (Sn), silver (Ag), and lead (Pb).

### Claim 4 (depends on 1)

The electrical connector structure of a circuit board of claim 1, wherein the adhesive layer is made of a material selected from the group consisting of copper (Cu), tin (Sn), lead (Pb), silver (Ag), nickel (Ni), gold (Au), and platinum (Pt).

### Claim 5 (depends on 1)

The electrical connector structure of a circuit board of claim 1, wherein the adhesive layer is made of one of phosphorus (P) and a solder material.