Dr. Beverly Crusher, Could you tell us a little bit more about your experience with PADS? We, I or many of manufacturing guys/gals are morons about chemical terminology. What's this oxy-business? How does PADS' process turn tin suface to oxyflu? What is your experience with PADS? Does it change the chemical property of tin surface to a molecular structure to inhibit corrosion? How thin is this coating? How long is the coating good? Any special process requirement for implementing the fluxless soldering in production? How practical is it for the future replacement of no-clean and water-soluble processes? Well, whatever info I have is good for marketing guys, and is too good to be true for mfg engineers. Throw away all existing known processes and go, go for the fluxless soldering? Wait a minute, I tested a similar thing with an electrically conductive epoxy for the future replacement of solderpaste. It turned out it was too good to be true for SMT manufacturing. I'm keeping these technologically advanced marketing secrets handy in case our senior management has a future vision of us to become a world-class manufacturer. Well there's no chance of that happening, our mfg operation is being marketed out, phased out, or booted out. Whichever way is convenient for my employer. Hope oxyflu is not one of those Asian flu. Sign out Matthew. >>> "Bev Christian" <[log in to unmask]> March 10, 1999 10:43 am >>> Technetters, A PADS unit can be purchased from Integrated Electronic Innovations in North Carolina (919-461-3773). I know a couple of other big companies have also played with this system besides us. PADS is especially useful if you positively cannot have any organic residues around, like say for an optical system. I wouldn't say it turns the surface oxide resistant but rather solder-philic. Somehow it transforms tin(II) oxide to either a tin oxyfluoride or perhaps there is a formation of a hydrogen bonded adduct between the surface oxide and hydrogen fluoride produced in the process. (Don't worry, from a corrosion point of view, the "coating" is so thin it is Bellcore compliant.) Of course there are always down sides to everything, right, even marriage? :) The system uses sulfur hexafluoride, which like CFCs, are relatively safe for humans but terrible environmentally. Now there is no chlorine so there is no threat to the ozone layer, but SF6 is one heck of a good global warmer. With CO2 having a global warming value of 1 SF6 has a value over 3000! The other thing is that it won't do much for tin(IV) oxide, so if you have old parts and boards you are out of luck. There are also other systems that are sometimes lumped in with fluxless soldering, like the SEHO formic acid vapor system of the early 90's, special very hot systems where reducing gases have been tried, and even the ROSA system that uses a vanadium based aqueous reducing solution. Of course we could start arguing semantics here, but that is not what I am trying to start. The point is there have been/are fluxless units, but I doubt that is what your marketing guy was after. These systems are not well known. regards, Bev Christian Nortel Networks > -----Original Message----- > From: Matthew Park [SMTP:[log in to unmask]] > Sent: Wednesday, March 10, 1999 1:09 PM > To: [log in to unmask] > Subject: Re: [TN] Fluxless Soldering > > Richard, > > This time, I guess, your design engineering manager is right. There is a > fluxless soldering process available. If I remember correctly, one process > I am aware is called *PADS* (Plasma Assisted Dry Soldering???). Wow... a > fancy jargon isn*t it? In this process, components or assembled boards > are exposed in a PADS treatment within a vacuum chamber. This treatment > turns soldering surface to oxide-resistant by modifying soldering surface > layer. From there, you can store components or assembled boards for a > specified period prior to wavesoldering, reflow or handsoldering. You > don*t need to apply flux to allow wetting, thus no cleaning is required. > > This process is ok for a lab application or a small production run. I > don*t have the info handy, but I am sure I have it filed away in my filing > cabinets. I can dig out something for you if you need to look further. > > Regards > Matthew > Norsat International Inc. > > > > >>> Richard Hamilton <[log in to unmask]> March 10, 1999 8:46 am >>> > Hello fellow TechNetters, > > Well, we were asked a question by the design engineering manager yesterday > if we had considered a fluxless soldering process. We are aware of a > process > called Solid Solder Deposit (SSD), but not a fluxless process by name. > > After the manager read us the email he got from one of the marketing > types, > I tend to believe that he was referring to no-clean process because of a > reference in his note about cleaning boards at a previous manufacturer > (TI). > My guess (oh how I hate to guess/assume) is that this marketing type has > just mixed up a couple of buzz-words together,.....kinda like 'military > intelligence'. I mean look at it, 'no-clean flux', I can see how a sales > person would want to shorten that to 'no-flux'. Now as usual, it is up to > us > manufacturing people to invent the process that has been sold to the > customer!! > > And as a side note: Steve - > > Your comments on machine maintenance are RIGHT ON!! You couldn't be more > correct. Sometimes I cringe at the way some machines are treated, and the > surprise that goes on when it does drop out! > > Thanks all. > > Richard Hamilton > Clemar Mfg. / Rain Bird > [log in to unmask] > > ################################################################ > TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c > ################################################################ > To subscribe/unsubscribe, send a message to [log in to unmask] with > following text in the body: > To subscribe: SUBSCRIBE TechNet <your full name> > To unsubscribe: SIGNOFF TechNet > ################################################################ > Please visit IPC's web site (http://www.ipc.org) "On-Line Services" > section for additional information. > For technical support contact Hugo Scaramuzza at [log in to unmask] or > 847-509-9700 ext.312 > ################################################################ > > ################################################################ > TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c > ################################################################ > To subscribe/unsubscribe, send a message to [log in to unmask] with > following text in the body: > To subscribe: SUBSCRIBE TechNet <your full name> > To unsubscribe: SIGNOFF TechNet > ################################################################ > Please visit IPC's web site (http://www.ipc.org) "On-Line Services" > section for additional information. > For technical support contact Hugo Scaramuzza at [log in to unmask] or > 847-509-9700 ext.312 > ################################################################ ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information. 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