Water-soluble soldering paste
US5069730A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 28, 1991 |
| Grant date | Dec 3, 1991 |
| Priority date | — |
| Expiry date | Jan 28, 2011 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K35/3612
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A water soluble solder paste, which does not adversely impact the surface insulation resistance (SIR) of a circuit board, is comprised of powdered solder, a water soluble flux (containing an activator within a water soluble vehicle), a hydrophobic surfactant preferentially absorbed over the water soluble vehicle, and a solvent within which the surfactant and flux are dissolved. The hydrophobic surfactant is chosen to be preferentially absorbed by the circuit board surface over the water soluble flux vehicle to prevent the vehicle, which is hydrophilic from becoming trapped in the board surface, thereby adversely affecting the board SIR.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.