Removal of residues from metallic insert used in manufacture of multi-layer ceramic substrate with cavity for microelectronic chip
US5643818A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 2, 1996 |
| Grant date | Jul 1, 1997 |
| Priority date | — |
| Expiry date | May 2, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/1517
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
After a metallic insert has been used precisely to define a cavity for a microelectronic chip in a laminated, multi-sheet, predominantly ceramic substrate having metallic features, any green sheet and metal-polymer composite paste residues are removed from the metallic insert by immersing the metallic insert in an ultrasonically agitated bath containing a first solvent having a relatively high boiling point for about five to fifteen minutes, replacing the first solvent with a second solvent having a relatively low boiling point, and drying the metallic insert in hot air or hot nitrogen to remove the second solvent. Preferably, the first solvent is an alkoxy alcohol, such as 1-methoxy-2-propanol or 3-methoxy-1-butanol, or a hydroxy ester, such as ethyl lactate, and the second solvent is a lower alkyl alcohol, such as isopropanol. Alternatively, the first solvent may be a ketone or an alkyl ester. The metallic insert is rinsed in the second solvent, preferably in an ultrasonically agitated bath, to replace the first solvent with the second solvent before the metallic insert is dried to remove the first solvent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.