Steve, "I envision that we will be building tin/lead products for quite a few years yet. Military minds don't change easily. Besides, there are exemptions for defense related electronics" if you follow Mike's advice, you will do no wrong ;-). As for the mil-mind, it is driven by all the obsolesces parts from commercial supply. The few years back, few of the chip supplies cancel many of their part numbers due to either (a) change to large wafer format, or (b) limited demand = few thousand aircrafts vs. million of commercial electronics. That leave the assembly producer with little choice: (a) re-spin the whole board with new "hi-rel commercial device with up-grating", normally you need re-qual of the assembly, or (b) do a life time buy of the parts and stored in N2 or any way you know how to keep the aircraft going (life time of the mil-aircraft is much longer than the 3-5 years of commercial electronics). Most of the so call "life time =last time buying parts are lead/tin finishing. (some of them are gold finishing, so you can store longer and tin them as you required.. those are ASICs, FPGAs, and microprocessors... large device size, so you do not have to worry too much about rad-hardening). most of the assemblies are try to keep the parts list compatible to each other, so you can buy "large qty", the qty still very very small compare to the commercial lot. If you start introduce leadfree, look like you will have to re-spin the board and re-qual at assembly level, if not at system level (I am sure those are new generation of devices, that is possibly sub-micron metallization for VLSI, if you are lucky... otherwise, you are dealing with ULSI. if it is really state of the art generation devices. As for new design, it should not be an issue. But the device selection will be limited at current level (after few years, it may be different). You are caught at rock and hard places... jk my 1.66 cents -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Steve Gregory Sent: Monday, December 06, 2004 2:02 PM To: [log in to unmask] Subject: Re: [TN] Lead-free, and not lead-free... Hi Ryan! Unfortunately, this isn't going to be a transitional thing for me, at least in the near future anyway. We're a contract assembly company that builds things for most of the the major DoD contractors, and most of them have told me informally that they aren't even thinking about lead-free. Some have actually put it into writing. I've pasted a few paragraphs as an example that was sent to us recently below (I've blanked out the company name: "At present, (Blank) will continue to order and assemble electronic products using tin-lead solder. There are currently no (Blank)customer contracts requiring transition to lead-free solders. There are, however, (Blank) customer contract requirements for (Blank) to continue using lead-based solders. These requirements are currently driven by a lack of community acceptance of reliability and design data to safely transition to lead-free solders. We are also concerned about our ability to guarantee the life of products, and our lack of process controls within (Blank)to manufacture with lead-free components. If there is a change in position, (Blank) will notify our suppliers of any new requirements. Presently, (Blank) is requesting that all suppliers provide lead-based electrical components and assemblies to (Blank) on all orders. (Blank)is monitoring industry work/study group efforts involved in lead-free solder transition, and while much still needs to be done, we are also establishing an internal program to evaluate transitioning to lead-free electronic assemblies, if and when that time comes." So, I have that stance from existing customers, and have just learned that we are pursuing business with a company that will have their products marketed in the EU, and must comply with WEEE and RoHS. So I find myself in quite a "pickle", as it were... I envision that we will be building tin/lead products for quite a few years yet. Military minds don't change easily. Besides, there are exemptions for defense related electronics. But if we're going to be build lead-free stuff along with tin/lead stuff, I'm inclined to agree with Mike Fenner and set-up completely separate areas with an impenetrable wall between them ;^) -Steve Gregory- Hi Steve, We're doing it no sweat! :) O.K., just kidding. Actually, it hasn't been too bad, we require our solder paste suppliers to visually mark their tubes with a "green" color so they aren't easily mixed. (Snip...) That would be easier to replace the eventually contaminated pot and keep pure. Ideally, you would convert all wave solder machines to lead-free, assuming all your leaded customers agree to the change. Then the only risk is production operators using the wrong solder paste. Good luck on the conversion. Ryan Grant -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Steve Gregory Sent: Saturday, December 04, 2004 6:21 PM To: [log in to unmask] Subject: [TN] Lead-free, and not lead-free... Hi All! I've got a problem that I've been worrying about all weekend. It may come to pass that we will be building both lead-free, and standard 63/37 stuff...whoa is me. I'm interested in stories from those that have done that...what the hell did you do? Is this something that can be done? It probably can, but me, being the pessimistic sort, thinks that you're just asking for trouble when you try to mix the two... -Steve Gregory --------------------------------------------------- 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 -----------------------------------------------------