If the new shop has issues etching 1 oz foil with line widths below 6 or 7 mils than again they must be carefully looked at. 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, July 28, 2004 7:05 AM Subject: Re: [TN] 1oz Copper vs. .5 oz Copper This is likely a capability issue - getting down below 6 or 7 mil lines and spaces the starting weight (what you are etching) of the foil needs to be less than 1 oz for good line resolution. Thicker conductors in denser geometries create a host of issues from conductor definition to soldermask coverage to ID screen legibility, etc. Jeffrey Bush Director, Quality Assurance and Technical Support 76 Technology Drive - POB 1890 Brattleboro, Vermont 05302-1890 Tel. 802.257.4571.21 Fax. 802.257.0011 [log in to unmask] http://www.vtcircuits.com -----Original Message----- From: Cal Driscoll [mailto:[log in to unmask]] Sent: Wednesday, July 28, 2004 8:20 AM To: [log in to unmask] Subject: [TN] 1oz Copper vs. .5 oz Copper Hi All- One of our PCB designers came to us with a recommendation from our Bare Board fab house- We typically use 1 oz copper and the fab house is asking us to use .5 oz copper and build it up to 1 oz. Since I am not a designer, so I would like some input from TechNet on this type of practice. Facts: 99% of our boards are used in Telecommunications products Most of our boards have QFP's in the 12 mil range Typically most of our boards have Gold pads/finish Thanks, cal --------------------------------------------------- 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 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- 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 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- 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 847-509-9700 ext.5315 -----------------------------------------------------