Methods and electronic board products utilizing endothermic material for filling vias to absorb heat during wave soldering
US6651869B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 21, 2001 |
| Grant date | Nov 25, 2003 |
| Priority date | — |
| Expiry date | Sep 21, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P70/50
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A method of wave soldering a circuit board while avoiding reflow of a solder joint on the topside of the board from heat conducted from the solder wave through at least one via in the board in heat conducting relation with the topside solder joint, comprises subjecting the circuit board to a solder wave and absorbing heat being conducted from the solder wave through the at least one via with an endothermic material in the via hole which undergoes a heat absorbing reaction. The heat absorbing reaction of the endothermic material is preferably a phase change, such as melting. The melted endothermic material is retained in the via hole during wave soldering by capillary forces and a cap on the lower end of the via hole. A disclosed method of making the circuit board includes locating the endothermic material in the via hole by inserting a preform of the endothermic material into the via hole or hot dispensing the endothermic material into the via hole. An electronic board product for practicing the method/made by the method is also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.