Ok, my turn to try and give back here...(thanks to all who replied to my question about availablity of cap arrays). 7781 E-glass means E= Electrical. E-glass is an aluminosilicate glass. 7781 = the yarn style (yarn, warp x fill and weight). "7781" just refers to the yarn style, not the finished material and sizes available or application. In your comparison shopping for "7781 E-glass" for PCB use you want to look for resin-compatibility as this varies from mfgr. to mfgr. depending on how the material is processed. Before weaving the yarn is sized with a binder or coating to maintain strand integrity and protect the fibers during the weaving process. After weaving the fabric is "desized" to permit adhesion between the glass fiber and chrome or silane finishing agents. Finally, the fabric is finished to give desired resin compatibility. There are conventional processed E-glass PCB yarns (usually with an oily starch) and there are some with newer coatings available now that are supposed to help eliminate heat cleaning ( a problem with the oil starch used for "sizing"), improve hydrolytic stability and increase overall laminate strength and stiffness among other things. Take a look at websites for Owens Corning, PPG Industries, Nippon among others for more info. -eom- At 11:52 AM 8/10/01 -0400, Steve Telgen wrote: >Hi, everyone, >Does anyone know what 7781 E glass is? It's supposed to be a type of >fiberglass material for PCBs. >TIA >Steve Telgen >IGK Industries --------------------------------------------------------------------------------- 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 ---------------------------------------------------------------------------------