A little note on water based fluxes. It is my and my colleagues experience that many assemblers use too much flux especially in the case of water based fluxes. It's always a good idea to put the extra effort into running a few trials turning down the application rate or application pressure to reduce the volume of flux applied. As implied below it is also critical to dry the boards with sufficient preheat, but the first step should be to turn down the flux volume. Best regards, Andrew Hoggan BBA Associates Ltd www.bba-associates.ltd -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Kasprzak, Bill (sys) USX Sent: 31 July 2001 12:56 To: [log in to unmask] Subject: Re: [TN] Fluxes Ray: One key factor in selecting an OA (water soluble) flux is whether the material is alcohol based or water based. During a qualification test that I ran years ago to qualify us for J-Std-001A, we selected a material which was a water based material. We ran some initial test runs using our typical solder profiles. When the circuit boards reached the wave, there was still enough moisture left on the boards from the flux. This resulted in a splattering effect similar to water in a hot frying pan except in this case, solder balls were evrywhere from the splattering effect! Making a long story short, I was finally able to correct for the situation but it took a while for me to accept and break the solder process paradigms. So if selecting an OA flux, and you want the make the process transition virtually seamless from RMA, select an alcohol based OA flux. By the way, you can never eliminate RMA. Do not solder stranded wires using OA flux!! Corrosive residues will be trapped under wire insulation resulting in broken wires at the wrong time. Bill Kasprzak Moog Inc., Electronic Assembly Engineering > -----Original Message----- > From: Golembiewski, Ray [SMTP:[log in to unmask]] > Sent: Friday, July 27, 2001 9:13 AM > To: [log in to unmask] > Subject: [TN] Fluxes > > I am looking for data analysis between a water soluble flux, and > an RMA. What are the major effects each has on a PCB. What do I have to > know before I make a switch from RMA to water soluble. If you might be > able to direct me to a link, or send me some information it would be > greatly appreciated. Thanks again, > > Ray Golembiewski C.I.D. > IPC Certified Interconnect Designer > Manufacturing Test Engineer > Projects Unlimited, Inc. > (937) 918-2200 > > -------------------------------------------------------------------------- > ------- > 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 > -------------------------------------------------------------------------- > ------- ---------------------------------------------------------------------------- ----- 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 ---------------------------------------------------------------------------- ----- --------------------------------------------------------------------------------- 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 ---------------------------------------------------------------------------------