Mark Which CTE are you interested in (X/Y or Z) and over which temperature range? The temperature range is especially important for the Z-axis CTE. I've looked into this over the last few years because I was finding seemingly conflicting information. I found some FR4 materials with published Z-axis CTE values of approximately 75 ppm/C and others at 175 ppm/C. This didn't make sense until I started looking at the range of temperatures that were used in the test. If testing is limited to below the Tg of the resin system, the CTE will be 75ppm/C or less. If the temperature range starts below and goes above the Tg values will be 150 ppm/C or higher. Z-axis CTE for FR4 above Tg may be as high as 300ppm/C. I hope this helps. > ---------- > From: Mark Gilbert[SMTP:[log in to unmask]] > Reply To: TechNet E-Mail Forum.;Mark Gilbert > Sent: Thursday, January 25, 2001 1:18 PM > To: [log in to unmask] > Subject: [TN] TCE for FR-4 > > Does anyone know the thermal coefficient of expansion for FR-4 offhand? > > Best Regards, > Mark Gilbert, Product Engineer > FOX Electronics > For Frequency Control Solutions. . . Fast: > 1-888-GET2FOX, ext. 2289 > Direct Line: 941-690-2289 > Fax: 941-693-1554 > > http://www.foxonline.com/ > > -------------------------------------------------------------------------- > ------- > Technet Mail List provided as a free service by IPC using LISTSERV 1.8d > To unsubscribe, send a message to [log in to unmask] with following text in > the BODY (NOT the subject field): SIGNOFF Technet > To temporarily halt delivery of Technet send the following message: SET > Technet NOMAIL > Search previous postings at: www.ipc.org > On-Line Resources & Databases > > E-mail Archives > Please visit IPC web site (http://www.ipc.org/html/forum.htm) for > additional > information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 > ext.5315 > -------------------------------------------------------------------------- > ------- > --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------