Electronics Forum | Wed Feb 21 15:29:34 EST 2007 | wavemasterlarry
I here alot of guys at my place talking about cold spots in the oven. You may want to check for them in yours.
Electronics Forum | Mon Feb 12 13:58:10 EST 2007 | campos
Tks for the answers,, My concern is about the intermetalic layer,,I run SMQ230 LEAD FREE paste.. its liquidous at 217C..the oven have 7 zone, but I run in 5 zones also with a more agressive profile (due to the line rate)..I would like to know if runn
Electronics Forum | Mon Feb 12 13:01:09 EST 2007 | campos
Hi all,, I running SMQ230 solder paste with a time above = 40sec with peak temperature = 239 degrees .. the complete reflow takes almost 6 min with a slope (150to190) close to .60 degrees/sec .. may I have some concern about that or it's ok?? tks..
Electronics Forum | Mon Feb 12 13:15:14 EST 2007 | realchunks
Does this meet the SMQ230 recommended time above liquidous? Do you have any parts that cannot withstand 239 degress C? If meet SMQ230's recommended time and temps and your parts are rated for this temp, then you should be OK. The real proof is ref
Electronics Forum | Mon Feb 19 08:00:46 EST 2007 | ck_the_flip
Darby, thanks for the good info. I actually read an article is Circuits Ass'y that a more rapid cooling rate results in "better diffused tin rich clusters" resulting in better grain structure. But...this article was written by an Oven manfuacturer
Electronics Forum | Mon Feb 19 08:18:03 EST 2007 | realchunks
That's why you have to read between the lines of any article. Even with data from a paste manufacturer, it's still a bit fuzzy on how their paste will actually work. Not many companies have their data that solid, so it's better to experiment and me
Electronics Forum | Fri Feb 16 13:43:07 EST 2007 | ck_the_flip
Hi Darby, Where did you get the info. that cooling rate is not-as-critical for lead-free? I'm not doubting you, and I actually want this to be the case. We don't have chillers on our ovens, and on fast profiles, we only achieve 2 to 2.5 deg. / s c
Electronics Forum | Mon Feb 12 13:16:35 EST 2007 | CK the Flip Guy
Looks good at first glance. Couple of questions, though: Time Above _____. Fill in the blank. Is Liquidous 183C (Tin-Lead) or 217C to 220C (Lead Free)? The "soak" of 150-190, at 0.6*C per second ramp up looks good, weather it's lead or lead-free
Electronics Forum | Wed May 03 20:24:22 EDT 2000 | Dave F
MF: I know of nothing that addresses your question directly. Let me suggest: * Technical types at your solder supplier should be able to help. * "Effect Of Intermetallic Compounds On The Thermal Fatigue Of Surface Mount Solder Joints" PL Tu, et a
Electronics Forum | Sun Feb 18 16:47:34 EST 2007 | darby
As I stated, the reply was direct from Indium, (thanks to Rich Brooks). The information regarding cool down rates should come from your paste supplier; not an oven supplier; not a generic article on lead free. I just went through the data sheets from
