Hello, There is a table in IPC-2221 (figure 7.2) that will give you the X-Y CTE of various materials. I have a figure that I think that I found in an article on the DuPont web site, comparing FR4 to their Thermount material, that quotes FR4 at about 20ppm in X & Y and 80ppm in Z. Hope this is some help. regards, Phil. At 15:33 10/04/00 -0700, you wrote: >Hi, >I am new to the list and have the following question: > >Where can I find the value for fr4 cte in the X direction? All of the charts >I have seen only refer to the Z. > >Leslie Gomez, CID >5791 Van Allen Way >Carlsbad, Ca >92008 >phone 760-438-6900 x 2382 >fax 760-438-6904 >email [log in to unmask] <mailto:[log in to unmask]> Phil Dutton C.I.D. Senior CAD Technician IPC Certified Interconnect Designer Vision Abell Pty Ltd Second Avenue, Technology Park, Mawson Lakes. SOUTH AUSTRALIA 5095 ================================ Phone : (08) 8300 4400 (reception) Fax : (08) 8349 7420 email: [log in to unmask] Internet Page: http://www.vsl.com.au ================================ ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ##############################################################