Electronics Forum | Mon Dec 13 14:13:39 EST 2004 | Gary
We are setting up our criteria for acceptance of solder voids. We would like 2% to 4% or smaller as our tolerance. Does this sound reasonable? Are most x-ray machines able to accurately measure at that size? Also, do most people find that 2% to 4
Electronics Forum | Mon Dec 13 14:41:41 EST 2004 | DasonC
Check IPC-7095, 7.4.1.6 For Class 2, 45% of the diameter adn 20.25% for the area.
Electronics Forum | Tue Dec 14 08:01:14 EST 2004 | paul_fisher
Our paste is no new we have used it before [Cobar no-clean paste]. The solder joints look like they are bursting out salty looking crystals. Maybe the board cleaning is a red herring in that if the boards are clean it stops this crystalisation travel
Electronics Forum | Tue Dec 14 11:34:34 EST 2004 | saragorcos
You may also want to contact Terry Munson at Foresite - he is very knowledgeable about the root causes of dendritic growth - you can reach him at 765-457-8095 - he can more than likely provide you with some good advice. Sara
Electronics Forum | Tue Dec 14 16:43:53 EST 2004 | Guest
Yes, the (large) company where I work has the policy not to use leadfree BGA's in the "old" process, so it's not unusual. Be prepared to have more customers having this opinion.
Electronics Forum | Thu Jan 13 09:55:42 EST 2005 | WDLau
Hi Dave, Then you think it is ok to use leaded (Sn/Pb) BGA with Lead free solder paste (SAC)and reflow process, As someone told it is not reliable and it should not be allowed to go,
Electronics Forum | Wed Dec 15 09:00:07 EST 2004 | russ
All of the SMT adhesives that I have used are non-conductive by themselves. I assume that the solder joints are formed by wave soldering?
Electronics Forum | Wed Dec 15 08:32:35 EST 2004 | ptavernier
Thank's Pete, I know is an old product but I would know its reflow thermal profile because I'm not sure about it. It's a linear melting or an melting with soak zone ? I haven't data on alphametals.com ...
Electronics Forum | Wed Dec 15 08:44:50 EST 2004 | cardinal
Hi Patrick, For UP 78 the best profile is also the easiest. Straight ramp to 220-225 1-2 degrees C per second TAL 45-60 seconds drop it staight off The Tech bulletin says the exact same thing. Former Alpha Guy here
Electronics Forum | Wed Dec 15 09:11:14 EST 2004 | ptavernier
Hi Cardinal, OK. Thank's. It's all right. What do you about SAC305 ? Do we use a linear melting too ?
