Strength depends on many things. Failure mode, first of all, as Joe is alluding to. If they are breaking mid-span and above the minimum required strength, and the wire lengths are the same, then the problem may be with the wire. If they are breaking at the neck of the ball or the neck of the stitch bond then it is a different problem. If they are breaking at the joint to the metal on the other surface then it may relate to the Ni, gold plating, metal or bonding parameters. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Joe Fjelstad Sent: Tuesday, January 05, 2010 4:12 PM To: [log in to unmask] Subject: Re: [TN] Pull strength of thermosonic wire bondable gold Hi Steve Your question brings up questions. Are the bonds, which are being tested and failing, stitch or ball? Can you notice any physical differences in the failures? Also what type of nickel plating are you using? It might be that a higher stressed nickel is fracturing in bonding and setting up the site to fail. Cheers, Joe In a message dated 1/5/2010 1:18:08 P.M. Pacific Standard Time, [log in to unmask] writes: Hi All, I have a wire bond question to the wire bond gurus who have helped me out a lot in the past. Made 2 versions of a flex circuit - only varied the nickel thickness. Application is thermosonic gold wire bonding. Flex circuit lead is .0032 wide - version 1 - nickel is 150 microinches - soft gold is 50 microinches- pull strength is X Version 2 - nickel is 40 microinches - soft gold is 50 microinches - pull strength is approx. ½X of version 1- Is this what I should expect? Regards Steve Kelly Steve Kelly (PLEASE NOTE NEW E-MAIL ADDRESS) (416) 750-8433 (work) (416) 750-0016 (fax) (416) 577-8433 (cell) --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 15.0 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 15.0 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 -----------------------------------------------------