Jim, We have seen it in GIL-style Polyamide. There are filler materials that are put into the "fill" area where the copper was removed. The process was used a lot when CIC is used with polyamide base material. The prepreg flows and coated the material, and the filler makes the 'filled' area less brittle. I have only bought boards like this. Personally never built boards using it. Don't know the parameters. The filler material might be a Ceramic. May not work in Cyanide. I can't think of any other disclaimers. Good Luck! George Franck Raytheon Systems Falls Church Virginia "My Opinions are just that." ---------- From: James A Larson <[log in to unmask]> To: [log in to unmask] Subject: [TN] Radial Cracks on Cyanide Ester resin Date: Mon, 8 Jun 1998 15:42:01 +0100 Has anybody experienced Radial Cracking as viewed from a horizontal section or Fishscale cracking as viewed from a vertical section using Cyanate Ester Resin. This resin system is used to fill a 2 oz. copper plane layer in a 8 and 10 layer board. If so what parameters have you compensated for to help minimize this situation? We've modified press parameters and drill parameters with minimal success. ################################################################ TechNet E-Mail Forum 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://jefry.ipc.org/forum.htm) for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################ ################################################################ TechNet E-Mail Forum 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://jefry.ipc.org/forum.htm) for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################