Electronics Forum | Fri Jul 12 07:15:45 EDT 2024 | murtaza
Use high tg material on pcbs. Like tg170 or higher. Its a bit more expensive. Board shops usually quote cheapest material just to win the order. When you see fr4 on the quote it usually means tg135-tg140.
Electronics Forum | Wed Feb 02 22:10:30 EST 2005 | T2
Higher Tg values are only one thing to look out for. Two other things that are very important to watch are the Td or Decomposition Temperature (the temperature that the epoxy actualy starts to break down), and the CTE for the material. Some Tg 14
Electronics Forum | Thu Jan 19 20:40:52 EST 2006 | Gary Kemp
We are experiencing a blistering problem during our process of lead free assembly. The customer has supplied us with the bare fab rated at 140 Tg. I am under the assumption that the Tg rating should at minimum be 170. Does anyone know if there is
Electronics Forum | Thu Aug 20 10:54:25 EDT 2009 | newpic
What is the minimum Tg for FR4 board to consider as Lead Free board? My issue is, I do not know what is the web for the V-Score for a FR4 Tg 180. I use to use a FR4 Tg 140 and there is no problem with it, but since we convert to Lead Free and the
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 | Fri Dec 16 18:37:10 EST 2005 | mdemos1
Hi. I am trying to understand Tg and how it relates to reflow. With the higher temperatures of lead free, we have been looking toward laminates with a Tg of 180 instead of the current 140. My question is a little more general. In either lead free
Electronics Forum | Tue Nov 16 18:02:29 EST 1999 | John Holland
What are the main advantages of moving from a 140 degree C FR4 laminate to a higher Tg laminate 180 degree C ?. Would the higher Tg laminate be less susceptable to bow and twist ?. John Holland
Electronics Forum | Fri Feb 24 10:21:59 EST 2006 | Board House
TM, When picking a material for your lead free assembly you need to think about a couple of things, The standard Material in the US that is being used is running 140 - 170 tg. material. But for lead free assembly you need to focus on is Decomp tem
Electronics Forum | Thu Jan 03 08:44:08 EST 2002 | davef
The Tg of the resin commonly used in FR-4 is 140�C. Consider checking with your supplier to better understand the specific materials used in constructing your board.
