The Tg meaning in PCBWay quotation system - Page 1
Forum section: electronics / general

author: ansonbao
author_rank: Regular Contributor
timestamp: February 27, 2018, 07:42:52 am
content: Some friends ever asked me what is the meaning of Tg when they make quotation on our website.I wrote ablogto explain the pcb tech. I share the post here to help more hobbyists:The Glass Transition Temperature (Tg) is one of the most important properties of any epoxy and is the temperature region where the polymer transitions from a hard, glassy material to a soft, rubbery material.Circuit board material must flame-resistant, it can’t be burned at a certain temperature and only be soften. The temperature point is called the glass transition temperature (Tg).The higher Tg point means higher temperature requirement during lamination. And the boards will be hard and crisp, which will affect hole and the electrical properties.Ordinary PCB materials at high temperatures, not only will be soften, deformation, melting and other phenomena, but also the mechanical and electrical properties decline sharply.General fr4 Tg is 130-140 centigrade, moderate Tg is greater than 150-160 centigrade, High-Tg is greater than 170 degrees.The higher of Tg, the better performance of PCB heat resistance, moisture resistance, chemical resistance, stability and other characteristics.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 27, 2018, 08:09:04 am
content: I usually see Tg=170C recommended particularly for RoHS process, and that's what we specify for production unless otherwise directed.Lower is more than acceptable for leaded process (US sales only?).Tim

author: ansonbao
author_rank: Regular Contributor
timestamp: February 28, 2018, 09:27:17 am
content: Quote from: T3sl4co1l on February 27, 2018, 08:09:04 amUsually Tg 130-140 can meet the requirement for hobbyists

author: mrpackethead
author_rank: Super Contributor
timestamp: March 02, 2018, 05:51:22 am
content: Quote from: T3sl4co1l on February 27, 2018, 08:09:04 amTim, you fell for the spam bait?

author: noras
author_rank: Contributor
timestamp: March 05, 2018, 07:15:59 am
content: For pcb exposed to high thermal loads, the necessary long-term operating temperature must be determined early on, in order to select an appropriate material. Typical application areas:Multilayer boards with many layers,Industrial electronics,Automobile electronics,Fineline trace structures,High temperature electronics...Which will involve CTE-Z,The CTE value shows the thermal expansion of the base material. CTE-z represents the z-axis and is e.g. due to the stability of the vias, of high importance. A higher Tg value favors a low CTE-z value which represents the absolute expansion in the z-axis. Errors like pad lifting, corner cracks and cracks within the via can be prevented through a low CTE-z value.

author: David Chamberlain
author_rank: Frequent Contributor
timestamp: March 09, 2018, 09:35:53 am
content: Just attribute your sources.https://www.multi-circuit-boards.eu/en/products/printed-circuit-boards/high-tg-pcb.htmlQuote from: noras on March 05, 2018, 07:15:59 amAlso are you the real Dido or just a fan?https://www.pinterest.com.au/pin/224405993913321913/?lp=true

author: noras
author_rank: Contributor
timestamp: March 12, 2018, 09:10:06 am
content: i'm only a fan, the noun's explanation can be good at using google, if i use the link it would be considered advertising.i think Material expansion factors should also be considered