Package substrate for electrolytic leadless plating and manufacturing method thereof
US6872590B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 24, 2003 |
| Grant date | Mar 29, 2005 |
| Priority date | — |
| Expiry date | Jul 24, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2203/1476
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Disclosed is a package substrate for electrolytic leadless plating, characterized in that a wire bonding pad onto which a semiconductor chip is mounted is subjected to electrolytic leadless Au plating, and a solder ball pad is subjected to OSP metal finishing or electroless Au plating without use of plating lead lines, upon preparation thereof. A method of manufacturing the package substrate is also disclosed. The method includes Cu plating a whole surface of a base substrate having through-holes, developing a first dry film laminated onto the through-holes, removing a copper foil not covered with the first dry film, stripping the first dry film, exposing and developing a second dry film on the substrate so that only an upper portion to be subjected to electrolytic Au plating is exposed, grounding an electrolytic Au plating terminal to a solder ball pad, Ni—Au plating the wire bonding pad, removing the second dry film by a stripping solution, exposing and developing a third dry film, removing the exposed copper foil by an etching solution, removing the third dry film by a stripping solution, performing a series of processes of coating, exposing, developing and drying a solder resis…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.