Method for examining surface of copper layer in circuit board and process for producing circuit board
US5633121A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 12, 1996 |
| Grant date | May 27, 1997 |
| Priority date | — |
| Expiry date | Jun 12, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2203/162
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The surface of a copper layer in a circuit board is irradiated with a beam, and the degree of progress of oxidation of the surface of the copper layer is determined by taking advantage of the resultant reflected beam (for example, an intensity or a hue of a reflected beam). Then, the step of coating a resist is carried out only when the thickness of the copper oxide film is not more than about 10 nm. Alternatively, the step of coating a resist may be carried out after removal or reduction of the oxide film or cladding of the oxide film with copper. The present invention enables occurrence of peeling of the resist or dive of plating to be prevented in the step of effecting selective etching or plating of a copper layer in a circuit board using a resist pattern as a mask.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.