Electronics Forum | Tue Aug 22 13:04:04 EDT 2000 | Eugene Smelik
Dr. Lee, Given the higher reflow temperatures for Pb-Free assembly, will common FR4 laminate materials be adequate, or do you believe that higher glass content boards will be required for mainstream Pb-free assembly? As a corollary question - if man
Electronics Forum | Thu Jan 19 21:43:33 EST 2006 | davef
Specifically, what element of the bare board is blistering? Tg of 140 could be acceptable. Search the fine SMTnet Archives for background on decomposition temperature [td]
Electronics Forum | Wed Nov 17 09:02:57 EST 1999 | Dave F
John: The 180 Tg point is a sweet spot for obtaining heat resistance, cost effectivly. These high technology boards provide good thermal resistance for wire bonding, direct chip attach, and BGA mounting and rework. Since these boards are harder th
Electronics Forum | Tue Aug 25 16:28:11 EDT 1998 | Al Knudson
Hello, Our PWB supplier has requested that a change in the laminate material to reduce the incidence of pad lifting. The standard laminate materials (Polyclad PCL-FR-226 with a glass transition temperature of 135 C) have greater z-axis thermal expan
Electronics Forum | Wed Jun 22 09:42:51 EDT 2005 | davef
Not sure what a higher Tg laminate will accomplish. Can't hurt though. Remember, when soldering to Alloy 42, the surface is 42% nickel. So, you need to raise the reflow temperature some 15 to 20*C over what is needed for copper. Also, sometimes All
Electronics Forum | Tue Feb 13 14:33:16 EST 2007 | CK the Flip
So the moral of the story is..... these SAC305 BGA's were accidentally mixed in with a Leaded process, the profile couldn't get hot enough due to Tg and Td constraints on a known good QFP on the same board, and consequently, the whole assembly fail
Electronics Forum | Thu Oct 26 09:10:30 EDT 2000 | ptvianc
I am not familiar with the "HALT" terminology. Do you mean HAST testing? As for thermal fatigue, the most severe conditions are typically those cited for military and/or satellite applications. There are several temperature ranges that are used to
Electronics Forum | Tue May 26 12:19:53 EDT 1998 | Earl Moon
| We currently bake plastic SMT parts in accordance with the IPC guidelines for moisture sensitive parts. Because we have double-sided boards that are subjected to either an aqueous or semi-aqueous cleaning process, we do a 24 hour bake at 125 deg.
Electronics Forum | Wed Aug 27 13:08:30 EDT 2008 | vladig
Td - is the degradation temperature for a laminate (board), while Tg - is glass transition one. There is one more (even more important) - delta Tg. They characterize the quality of the laminate material. Regards, Vlad www.sentec.ca
Electronics Forum | Mon Feb 16 11:30:10 EST 2015 | clydestrum
Could anyone point me in the direction of finding out how much strength an SMT pad has in relation to being pulled away from the substrate/laminate? We are in process of trying to build a 6mil thick board and want to know if a chip can be placed onto
