try plasma etching with argon gas; this will preferentially etch grain boundaries without much effect on the metal crystal itself. > Bill Davis, Ph.D. > Diamond Multimedia Systems > Senior Scientist > Tel. 408.325.7868 > Cell. 408.888.5650 > e-mail: [log in to unmask] > > -----Original Message----- From: Werner Engelmaier [mailto:[log in to unmask]] Sent: Monday, May 24, 1999 1:34 PM To: [log in to unmask] Subject: Re: [TN] Copper grain size In a message dated 5/24/99 10:12:01, [log in to unmask] writes: >Hello Engelmaier! >How does it change does it increase or decrease? Do you know >any information about etchants to decorate grain boundaries. >Thanks, >Yasmeen Hi Yasmeen, The grains generally increase in size during annealing, but more importantly they change shape. Most commercial electrodeposited copper foil has a columnar grain structure where the grains are packed columns running through the thickness of the foil; there also is a difference in the machine and cross-machine directions. Rolled copper foil has a needle-like structure with the needles running in the rolling direction of the foil; this produces large (much larger than E-foil) differences in foil properties in the machine and cross-machine directions. Annealing will produce more uniform grain structures. For the appropriate etchants (they depend on what in the grain structure you want to emphasize) I need to send you to experts in this area. Since your internal lab does not seem to be experienced in this area, I would suggest to have the cross-sectioning, polishing and etching done by a commercial laboratory. Any of the labs that are IPC members can be recommended (I have seen some rather bad results from some other labs); so pick one conveniently located to you out of the IPC membership directory. Werner Engelmaier Engelmaier Associates, L.C. Electronic Packaging, Interconnection and Reliability Consulting 7 Jasmine Run Ormond Beach, FL 32174 USA Phone: 904-437-8747, Fax: 904-437-8737 E-mail: [log in to unmask], Website: www.engelmaier.com ################################################################ 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's web site (http://www.ipc.org) "On-Line Services" section 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's web site (http://www.ipc.org) "On-Line Services" section 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################