Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Pb-Free solder alloying with finish on components

galltp

#6325

Pb-Free solder alloying with finish on components | 22 August, 2000

Dr. Lee,

We have seen a small decrease in shear strength for Pb/Sn plated components attached with Sn/Ag/Cu solder compared to components with a Pb-free finish. With the jump in the cost of Pd, we are struggling to define a practical Pb-free finish for components to use with Sn/Ag/Cu solder. Do you think that we will see a solution to Sn wiskering problems, or will some other finish be used for Pb-free soldering?

reply »

Dr. Ning-Cheng Lee

#6326

Re: Pb-Free solder alloying with finish on components | 22 August, 2000

The classic dilemma, cost vs. performance.

In typical applications, Sn whisker growth is not an issue. It only seems to occur under extreme use (high stress, low temperature)conditions. Until this issue is fully addressed, Pd seems to be the favorite answer.

Pd plating, while more expensive, presents no known problems.

reply »

SP700avi inline stencil printer

 Reflow System