We have many customers requesting lead free materials. We use a specific material with a higher Td which is specifically designed for lead free and is widely used in Asia where the lead free initiative is much further along. Our lead free material is actually less expensive than the current "dicey" cured materials we use for non lead free assemblies. If you want more information please feel free to contact me off-line. James Hofer Director of Operations Accurate Circuit Engineering 3019 S. Kilson Dr. Santa Ana Ca. 92707-4202 714-546-2162 work 714-473-6127 cell [log in to unmask] ----- Original Message ----- From: "Jeffrey Bush" <[log in to unmask]> To: <[log in to unmask]> Sent: Wednesday, November 24, 2004 12:34 PM Subject: Re: [TN] FR4 and Lead free The issue is not Tg but Td. Some higher Tg materials actually perform worse than lower Tg materials. It is important develop a test program to validate your lead free process with specific base materials. Laminate manufactures offer some variety of thermally stable materials targeting lead-free, but these are used at a premium. If your lead-free process can be supported by existing base materials, than that is best economic solution. The test program will provide the feedback needed. Please contact me off-line if you need specific information on alternate base materials and Td for lead-free. Jeffrey Bush Director, Quality Assurance and Technical Support VERMONT CIRCUITS INCORPORATED 76 Technology Drive - POB 1890 Brattleboro, Vermont 05302 Voice: 802.257.4571.21 Fax: 802.257.0011 http://www.vtcircuits.com -----Original Message----- From: Black, Paul [mailto:[log in to unmask]] Sent: Wednesday, November 24, 2004 3:08 PM To: [log in to unmask] Subject: [TN] FR4 and Lead free Hi Tech Gurus, As people talk more and more about Lead free, I keep hearing that standard FR boards might not be able to take the extra heat required for a reliable Lead free solder joint. The problem is that I keep hearing the word MIGHT. I have not heard that this is definitely true and, if it is true, I have not heard anyone offer a cost effective solution. So, I am asking the many experts on this forum, will standard FR4 be able to handle the higher excursions (particularly, let's say, for a 7" X 9", 8 layer, double-sided SMT, .062" 5/5 board) associated with Lead free solder paste? If not, what would be the most cost-effective offering (i.e. high Tg FR4)? Thank you, Paul Black Manufacturing Engineer Kronos --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------