Title :
Silver Nitric-An innovative process indicator for oxidation of PCB with OSP finish
Author :
Hou, Eric ; Chung, D.F. ; Wang, Paul
Author_Institution :
Mitac Int. Inc., Foshan, China
Abstract :
Oxidation on PCB due to shelf life and environment stresses is a severe problem in the soldering process. In this article, the chemical agent of Silver Nitric is used to react with OSP coated-cupper pad. By measuring the time to discoloration, the severity of oxidation can be quantitatively classified by solder wettibility. Variables such as storage time, temperature & humidity, reflow cycles are adapted as pre-conditioning to emulate shelf life and environment stress and to use as failure precipitation mechanism for oxidation on cupper pad. Using discoloration as an innovative process indicator, the hardening of OSP coating can also be reviewed.
Keywords :
coating techniques; copper; oxidation; printed circuits; silver compounds; soldering; solders; OSP coated-cupper pad; OSP coating hardening; OSP finish; PCB oxidation; environment stresses; failure precipitation mechanism; humidity; innovative process indicator; reflow cycles; shelf life; silver nitric; solder wettibility; soldering process; storage time; temperature; time-to-discoloration; Chemicals; Coatings; Color; Copper; Films; Heating; Image color analysis; OSP; Organic Solderability Preservative (OSP); PCB; Silver Nitric AgN03; hole fillet; lead-free; lead-free soldering; process indicator; surface finish;
Conference_Titel :
Electronic Packaging Technology and High Density Packaging (ICEPT-HDP), 2011 12th International Conference on
Conference_Location :
Shanghai
Print_ISBN :
978-1-4577-1770-3
Electronic_ISBN :
978-1-4577-1768-0
DOI :
10.1109/ICEPT.2011.6066930
