HI ! EVERYBODY
I HAVE A PROBLEM.
AFTER I/R REFLOW PROCESS, PCB WAS DISCOLORED AROUND
GOLD PLATING, ESPECIALLY EXPOSED EPOXY AREA CHANGED
LIGHT VIOLET.
THE PCB WAS APPLIED A HASL PROCESS AND EDGE CONNECTOR
GOLD PLATING. WE TESTED MANY TIMES AND ONLY PCB WHICH
WAS APPLIED THE HASL PROCESS AND GOLD PLATING PROCESS.

THERE IS LOW PEAK OF Sn BY SEM ANALYSIS ON THE DISCOLORED
SPECIMEN ONLY.

THE GOLD PLATING CHEMICAL MAKER SAID :
IF AMINO-COMPOUNDS WHICH IS USED HARDNER OF EPOXY
MATERIAL JOIN WITH A CYANIDE, PCB CAN DISCOLORATION AFTER
THERMAL SHOCK.

PLEASE HELP ME WHY THE PCB WAS DISCOLORED AS SOON AS
POSSIBLE.

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