If this helps, the chart I have shows the temperature range from -20 to +80 at 2 GHz. The increase in Dk is also about 0.15. Glenn Pelkey Maxtek Components Corp. [log in to unmask] Wrote: | | | Hi Walther, | Dk goes up by about 0.15 from 20 C to 120 C where my graph ends - so for example 4.8 | becomes 4.95. This holds true between 1 MHz and 100 MHz - again I have no data beyond that. | If you go up to 150 C you are above Tg. I can only guess that there will be a change at Tg but how | much and in which direction? This is not going to be a useful property as FR-4 is not stable long | term at 150C. | Regards | Dave Heywood. | [log in to unmask] | ---------- | From: [log in to unmask] | To: [log in to unmask]; Dave Heywood | Subject: Dielectric constant of FR4 - temperature | Date: 15 July 1997 22:26 | | <<File Attachment: ENVELOPE.TXT>> | I have a question regarding dielectric constant of FR4. | How does Dk change in case you increase the temperature from room temperature | to maybe 150 degree C.| I remember I have seen once a curve somewhere, which | showed Dk increasing drastically when the temperature went up. | Is this correct and what would be the explanation behind. | | Walther *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************