Thank you for all your answers. Within the last year and a half, we have started embarking on several OEM products in addition to products we market ourselves. One of the OEM requirements is to use a tier one contract manufacturer. Previously we have acted as our own CM - we have the boards fabbed at one place, sent back and then we send them somewhere else for populating. Our newest products have no thru hole at all, however many of our older products usually have several thru hole components, connectors, etc, that we hand install in house. I joined this forum and started to realize that we have very few controls or specs in place for our outside suppliers. We just take what they give us. I am not new to the co. but in a new position to the company, manu. engineer, and have started to try to clear up some of these glaring holes in our documentation. On our production floor, two types of solder wire are typically available - the Kester 44 63/37 RA core, or a no clean Kester 245 63/37 which is classified as ROL0. The no clean is typically only used to solder on shielding cans or connectors that are visible to the customer, because less cleaning is needed. For any thru hole, in house ECO parts changes, or installing shortages, the 44 is used. Some of the component lands it is used on would have had solder paste from the reflow process. We do hand spot cleaning of the flux with M.G. Chemicals Safety Wash which is composed primarily of ethanol and methyl alcohol. I have been told by Kester that the two fluxes mentioned above should not cause any problems when mixed. Any further input is appreciated. We do not yet use any BGA's on our products. -----Original Message----- From: [log in to unmask] [mailto:[log in to unmask]] Sent: June 19, 2001 6:39 AM To: TechNet E-Mail Forum.; Genny Gibbard Subject: Re: [TN] No Clean and Rosin core on same PCB We have CM's that use no-clean solder paste on our PCB's. We have not given the CM any spec other than that it be approx. 60/40 tin-lead. In house, however, for hand assembly we have always used solder such as Kester "44" RA core solder. We're working on a new OEM product and the customer has expressed concerns about mixing the two on the same PCB. We also use a safety wash board cleaner. Any thoughts or concerns that we should address? **Genny, you may have a possible materials incompatibility issue. You do not say whether the Kester 44 you use in-house goes on the low solids paste residues from the contract manufacturer. Are they doing the primary build, with you hand soldering in some final parts in house? Or are you trying to direct your contract manufacturer what to use in their hand soldering operation? You say that you have a safety wash process. What are the chemicals in that wash process and what is the low solids solder paste that your contract manufacturer is using? In general, if you can give lots of specifics on the materials and processes involved, you can get direct answers a little easier. This is a fine forum and the more you tell us about the background, the better guidance we can give. Doug Pauls Rockwell Collins (which, after our spin off the end of this month, will be....... Rockwell Collins. Please hold down the gasps of astonishment). --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d 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 delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------