Laser marking method and ablative coating for use therein
US4707722A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 9, 1987 |
| Grant date | Nov 17, 1987 |
| Priority date | — |
| Expiry date | Jan 9, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Laser marking of metal surfaces, particularly semiconductor device packages, is accomplished by depositing an electroless nickel layer on the surface, converting the nickel surface to a form in which it is highly absorptive of radiant energy and exposing the converted nickel surface to laser energy through a mask. The resulting mark is highly resistant to abrasion and corrosion. In addition, the method is highly suitable for use with automated laser marking equipment. Furthermore, it appears that the presence of the converted electroless nickel surface in the region of welds increases the hermeticity of the welds. This is particularly useful in packages of the TO-3 type and similar types.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.