Method for manufacturing printed circuit board

• US 7,208,341 B2
• Filed: 05/28/2004
• Issued: 04/24/2007
• Est. Priority Date: 05/30/2003
• Status: Expired due to Fees

• Current Assignee: LG Electronics, Inc. (LG Corporation), LG Innotek Company Limited (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Lee, Sung-Gue, Youn, Sung-Ho, Lee, Kwang-Tae, Nam, Sang-Hyuck, Lee, Young-Kyu
• Primary Examiner(s): TRINH, MICHAEL MANH
• Application Number:
  US10/855,557
• Publication Number:
  US 20040241904A1
• Time in Patent Office: 1,061 Days
• Field of Search: 438/106, 438/618, 438/622, 438/125
• US Class Current: 438/106
• CPC Class Codes: H05K 2201/0959 Plated through-holes or plated blind vias filled with insulating material
• CPC Class Codes: H05K 2201/09881 Coating only between conductors, i.e. flush with the conductors
• CPC Class Codes: H05K 2203/025 Abrading, e.g. grinding or sand blasting
• CPC Class Codes: H05K 2203/0577 Double layer of resist having the same pattern
• CPC Class Codes: 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
• CPC Class Codes: H05K 3/28 Applying non-metallic protective coatings H05K3/0091 takes precedence; methods for intermediate insulating layers for build-up multilayer circuits H05K3/4673
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base

Abstract

A method for manufacturing a printed circuit board includes: forming inner circuit patterns in an insulating material in multi-layers, forming a plurality of through holes at certain portions of the insulating material, and forming an outer circuit pattern which is electrically connected to the inner circuit pattern, at an inner circumferential surface of the through hole and the surface of the insulating material, and a terminal portion; forming a first photo solder resist layer at an entire surface of the insulating material and an entire surface of the outer circuit pattern, and exposing the terminal portion by removing a specific portion of the first photo solder resist layer; abrading the surface of the first photo solder resist layer; printing a second photo solder resist layer at the surface of the first photo solder resist layer, and exposing the terminal portion to the outside by removing a specific portion of the second photo solder resist layer; and forming a pad portion by plating the surface of the exposed terminal portion with gold, and electrically connecting the pad portion and the terminal portion.

Claims

1. A method for manufacturing a printed circuit board comprising:

forming inner circuit patterns in an insulating material in multi-layers, forming a plurality of through holes at certain portions of the insulating material, and forming an outer circuit pattern which is electrically connected to the inner circuit pattern, at an inner circumferential surface of the through hole and the surface of the insulating material, and a terminal portion;

forming a first photo solder resist layer at an entire surface of the insulating material and an entire surface of the outer circuit pattern, and exposing the terminal portion by removing a specific portion of the first photo solder resist layer;

abrading the surface of the first photo solder resist layer;

printing a second photo solder resist layer at the surface of the first photo solder resist layer, and exposing the terminal portion to the outside by removing a specific portion of the second photo solder resist layer; and

forming a pad portion by plating the surface of the exposed terminal portion with gold, and electrically connecting the pad portion and the terminal portion,

wherein, in the removing the specific portions of the first photo solder resist layer, the specific portions of the first photo solder resist layer are exposed to a UV beam and then developed.

2. The method of claim 1, wherein the first and second photo solder resist layers are made of photosensitive ink.

3. The method of claim 1, wherein the first and second photo solder resist layers are made of photosensitive epoxy resin.

4. The method of claim 1, wherein, in the abrading, the surface of the first photo solder resist layer is abraded only as deep as a depth of a sinking portion formed at a specific portion of the first photo solder resist layer.

5. The method of claim 1, wherein, in the removing the specific portions of the second photo solder resist layer, the specific portions of the second photo solder resist layer are exposed to a UV beam and then developed.

6. The method of claim 1, wherein, after the pad portion is formed, the surface of the second photo solder resist layer and the surface of the pad portion are flattened.

7. The method of claim 1, wherein in the forming a pad portion step, the height of the pad portion is plated as high as a height of the second photo solder resist layer.