Asahi Viromet Lead Free Paste

Tested recently on ENIG finish. profile as follows 100-150, 57 sec. 150 210, 46 sec. 210 + , 63 sec. Peak 231. This profile was developed for this paste as per Asahi literature. Operator said it "looked wet and smelled good"! Print quality was excellent. Wetting was not as good as the SAC pastes we tested. Solder balls and beads apparent. None with the SAC pastes. Flux residuals were the most of any paste we tried.

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Yes, I am currently using Viromet 347 at the moment for my SMT lines. 100-150, 35 sec 150-207, 40 sec 207-above, 80 sec peak temp: 225 deg C. It is compatible to SAC paste in term of solderability and wettability. But in term of mechanical property (compared to both technical spec from the website), Viromet is better than SAC. Whenever it comes to any board with BGA ICs, I can have better control (bcos of its low melting temp), the middle of the BGA's ball, I controlled its peak at 225 deg C, and it will not affect my others components on the board. For eg, middle of the ball is 225 deg C of its peak temp, and the QFP is around 230~235 deg C. Unlike SAC, if I control its peak of the BGA at 235 deg, the QFP is 245 and more. That is why I changed from SAC to Viromet for my better control of my process, and good for the product as well (better mechanical properties, and prolong the life span of the product!).

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