Method for removing molding residues in the fabrication of plastic packages for semiconductor devices
US6468356B1 · kind B1 · utility
Assignees
Inventors
Key dates
| Filing date | Mar 27, 2000 |
| Grant date | Oct 22, 2002 |
| Priority date | — |
| Expiry date | Mar 27, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/4839
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method for removing residues of molding material from metal parts of plastic packages of semiconductor devices includes applying first and second pulsed laser radiations to at least one surface region of a metal part covered with residues of molding material. The first pulsed laser radiation has a first wavelength that is absorbed by residues of molding material having a thickness greater than a prescribed thickness. The intensity and the duration of the first pulsed laser radiation causes the residues to be directly attacked. The second pulsed laser radiation has a second wavelength so that residues of molding material having a thickness less than the prescribed value are at least partially transparent and the metal parts are at least partially absorbent. The intensity and the duration of the second pulsed laser radiation causes the formation of plasma at the point of impact with the metal part.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.