Electronics Forum | Fri Nov 02 03:26:40 EDT 2012 | spopov
Hello! We want to try Lead Free paste Sn42/Bi58. Can we use this paste with Lead fihish such as HASL. I am worry about low melting temperature of 138C.
Electronics Forum | Tue Nov 06 22:14:10 EST 2012 | nikyta
Hi Popov, can you tell us the reason for the use of Sn-Bi ?
Electronics Forum | Thu Nov 15 03:07:35 EST 2012 | nikyta
Thanks for your reply. As already said by Anvil1021, is not a good idea to mix Lead and Bismuth! Stay away from Bismuth if you have even the slightest traces of Lead on yours PCB, stencil, squeegee, spatula, blade, cleaning paper or cleaning cloths,
Electronics Forum | Wed Nov 07 15:01:18 EST 2012 | nikyta
Thanks Dave , my question is about Spopov want to try "Lead Free" SnBi (but uses it on Leaded finishes), but is worry about its low melting point (at this point, no longer 138 degrees as he wrote, but rather in an unknown and unpredictable range bet
Electronics Forum | Wed Nov 14 03:26:38 EST 2012 | spopov
Ryan, in some cases we use 2 pastes with different melting temperature (LF SAC and PbSn)for complex boards with components on two sides. And we want to try to replace LF SAC with low melting paste.
Electronics Forum | Fri Nov 02 09:09:56 EDT 2012 | davef
Sure you can use it it with leaded HASL. Recognize that ... * Your Sn42/Bi58 will no linger be Sn42/Bi58 * Your leaded HASL will no longer be the same leaded HASL that walked in the door to your plant * Lead from HASL coatings can diffuse through the
Electronics Forum | Fri Nov 02 14:46:18 EDT 2012 | ericrr
So how does this (lead free paste Sn42/Bi58) solder compare with the Sn-Ag-Cu (Tin-Silver-Copper) combination which does not flow as well (in the oven), needs higher oven temperature, (that can be adjusted by reducing the oven chain speed) and cost m
Electronics Forum | Tue Nov 06 22:37:35 EST 2012 | davef
Ryan ... "As for bismuth-based lead-free alloys, a lower melting temperature than that of tin-lead is offered together with a cost similar to that of tin [in the area of $3/lb]. Unfortunately, bismuth in soldering alloys tends to create embrittlemen
Electronics Forum | Sat Nov 03 11:20:35 EDT 2012 | davef
EricR: There's substantial information about the properties of solder alloys on the web. Here's an example of something that I clipped from one site Alloy ||Solidus (°C)||Liquidus (C°) ||Tensile Strength (psi / MPa) Sn42 Bi58||-E-||138||8000 / 55.2
Electronics Forum | Sat Nov 03 11:08:24 EDT 2012 | anvil1021
We have experience with this alloy, but with enig and we did start with PB HASL, none of our PCBs would of course pass thermal cycling at normal temperatures with the HASL so we went to ENIG. we could thermal cycle at 100-115C with no issues. We foun
