Electronics Forum | Tue Feb 03 03:35:30 EST 2009 | sachu_70
Hi Jose, such a process is possible, but you need to confirm that the PCB material has high Tg. In additon, you need to re-look solder paste printing parameters and make required changes in stencil apperture design for optimum solder volume. Just a
Electronics Forum | Fri Feb 23 09:12:13 EST 2024 | carl_p
How have you created the oven profile? Have you taken into account the heat soak from the components/board/carrier etc. Is the paste being mixed correctly before use, is the paste in its use by date & at ambient temp etc? I thought almost all the
Electronics Forum | Fri Feb 23 09:55:02 EST 2024 | carl_p
Got you. 225C for peak does seem low to me. Henkle is the main one i've used with a peak of 245c & Alpha around the same although I try to keep that at no higher than 235C as we use it for LED arrays. If the peak is that low, is the liquidus te
Electronics Forum | Fri Feb 23 11:29:02 EST 2024 | carl_p
Would you be able to post an image of the joint in concern? Sounds a good problem to resolve. Guessing you have used an external profiler & not the oven built in type? If 100% certain the profile is correct I would focus on the paste from my exper
Electronics Forum | Fri Feb 23 09:35:36 EST 2024 | emanuel
We have the standard profile as a template made according to the solder paste specs. For some boards we measure the result at 2 points, on the board itself and on top of a sensitive SOT263 module and adjust accordingly. The solder paste is well kept,
Electronics Forum | Tue Aug 22 09:49:39 EDT 2000 | galltp
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
Electronics Forum | Mon Mar 05 18:20:44 EST 2007 | ratsalad
We buy our paste in Semco cartridges. You don't need a pneumatic gun to administer the paste to the stencil, just use a caulk gun which you should be able to purchase at your local hardware store. The cheap ones are about $2 (US). We have green
Electronics Forum | Tue Jun 27 08:38:03 EDT 2006 | cuculi54986@yahoo.com
I tried some SN100C from AIM... On only one array. It flowed well on the chips but did not like the finish on the SOT23's on the board. I did not have enough arrays to mess around, so we switched it over to SAC305 and had no issues. I'm guessing w
Electronics Forum | Mon Feb 04 14:42:08 EST 2008 | ratsalad
Are you talking about Durastone? That's what we use for our wave pallets. Both our wave vendor and solder bar vendor told us that we had nothing to worry about as far as Pb-contamination of the pallets. We have used the same pallets across our Sn
Electronics Forum | Sat Feb 10 17:12:03 EST 2001 | rpereira
I admit, 16 mil QFP printing is very challenging but if all your control factors (print speed, etc...) are setup correctly (through DOE) extremely high yields can be achieved and more importantly a repeatable and robust product will be manufactured.
