Electrical conductors with chromate solder barrier and method of forming
Abstract
Abstract PRINTED CIRCUIT CONDUCTORS ARE SELECTIVELY COATED WITH A CHROMATE CONVERSION FILM TO CONFINE MOLTEN SOLDER TO SELECTED AREAS DURING REFLOW AND THEREBY PREVENT WICKING METHODS OF APPLICATION ALLOW IMMERSION COATING OF THE CHROMATE, EITHER WITH OR WITHOUT SOLIDIFIED, SOLDER PRESENT IN THE SELECTIVE AREAS. WITH SOLDER PRESENT, A PASSIVATION LAYER IS FORMED ON THE SOLDER TO PREVENT CHROMATING DEPOSITION, AND WITHOUT THE PRESENCE OF SOLDER A REMOVABLE PROTECTIVE RESIST IS APPLIED TO PREVENT CHROMATING ON THE SELECTED AREAS. THE CHROMATE CONVERSION COATING WITHSTANDS SUCCESSIVE FLUX APPLICATIONS AND REHATING FOR REPETITIVE ASSEMBLY AND DISASSEMBLY OF THE SOLDER JOINTS WITHOUT ALLOWING SOLDER RUNBACK.
Inventors
- 👤 T Ameen
- 👤 N Mesley
Bibliographic Details
Claims Analysis
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1977-08-05 | 1978-02-04 | 1978-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-05 | 1982-02-04 | 1982-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-05 | 1986-02-04 | 1986-08-06 | $7700.00 | Window Closed / Lapsed |