Well put Doug !! James Hofer Director of Operations Accurate Circuit Engineering 3019 S. Kilson Dr. Santa Ana Ca. 92707-4202 714-546-2162 work 714-473-6127 cell [log in to unmask] ----- Original Message ----- From: "Douglas O. Pauls" <[log in to unmask]> To: <[log in to unmask]> Sent: Wednesday, September 01, 2004 9:22 AM Subject: Re: [TN] Cleaning populated boards with Isopropyl > Grand Wazoo? <snort> Kinda gives "out tha wazoo" a whole new perspective. > > As to your recommendation for cleaning machines, I would agree. Both > companies make some good cleaners. > > Let's dissect Paul's situation: > > I currently clean SMT stencils in a sink with hot deionized water. > > **So you are putting lead down the drain?. Might be some local effluent > laws waiting to bite you. Might want to check on that with your local POTW > or EPA folks. > > I would like to automate this process (and eliminate the DI water) and have > been looking at cleaners that can do the job. > > **Automation is good. Automation is consistent. And DI water is your > friend, not your enemy. Tap water is the Darth Vader of materials. > Remember that. > > One of them uses Isopropyl Alcohol with no rinsing. > > **Which means you have a cloud of flammable vapor inside the machine. Is > it explosion-proof? What does your local fire marshall have to say? Does > the machine empty the workspace of fumes before you open it. Having spent > the last 20 years cleaning the insides of humidity chambers with > isopropanol, I can say you get some wonderful hallucinations from the > fumes, but not something you want to do on a regular basis. Also, the use > of IPA may also affect your VOC emissions for EPA compliance. In terms of > the material, does your paste manufacturer indicate that pure IPA will > remove all of the paste residues? Does the machine capture the lead in a > trap somewhere? If yes, does it get recycled? If not, you have a > hazardous waste situation. DI water is cheaper than isopropanol, > especially when you start counting the cost of handling flammable > materials, storage, fire suppressions, Aunt Gladys going home with fume > headaches each day.... > > This should work fine for the stencils but occasionally I also have to > clean misprinted boards that may already be populated on one side, using > no-clean solder paste. If I were to use this Isopropyl process on the > misprints, would I be risking reliability of the board? > > **Arrghhhhhhhhhhhhhhhhh! Burn the Heretic!!!!! Ummm, not a practice you > want to use. First, IPA is a lousy cleaner of flux residue, reflowed or > not. DI water alone is not much better. One advantage with either is > that paste residues that are not reflowed are easier to clean, but you > would have to get used to seeing a white haze on your boards. The only > advantage I see from IPA only is that the stencil comes out dry. What I > suggest is that you use DI water, with a small amount of a cleaning agent > that works with your paste. We use a lot of Kyzen products at Rockwell and > I have found their technical staff to be very good in matching the right > material to the right soil. Many products can go to drain as long as you > capture the lead. In the products we use, the micro-critters at the waste > treatment site love the Aquanox chemical. To them, Rockwell is Delmonico. > > In terms of reliability, I would never take the chance with our products of > getting those iddy biddy spheres of solder somewhere they don't belong or > places where you cannot remove them. They will see reflow conditions > before they see another mass cleaning. So relays, connectors, under fine > pitch devices, BGAs, air wound coils and transformers, etc., all become > compromised if those solder balls reflow in place. Bare boards, > maaaaaaaybe, but assemblies, no way. > > OK, beaming back up to the mother ship. > > Doug Pauls > > > > > Phil Nutting > <PNutting@KAISERS To: [log in to unmask] > YSTEMS.COM> cc: > Sent by: TechNet Subject: Re: [TN] Cleaning populated boards with Isopropyl > <[log in to unmask]> > > > 09/01/2004 10:17 > AM > Please respond to > TechNet E-Mail > Forum; Please > respond to Phil > Nutting > > > > > > > I'm interested in what the "Grand Wazoo" Doug Pauls and Brian Ellis have to > say about this. If I've read their musings correctly alcohol does a nice > job of spreading the ionic schmootz where DI water cleans it very well. > > If my research is correct, there are several automated DI water stencil > cleaning systems readily available on the market (www.aqueoustech.com > www.aat-corp.com to name just two) and these suppliers also make batch > style board cleaners. Austin American (aat-corp) has a new unit on the > market for under $10k. > > Oops, was that too close to a sales pitch? > > Why would you want to "eliminate DI water"? > > Phil > > -----Original Message----- > From: TechNet [mailto:[log in to unmask]]On Behalf Of Black, Paul > Sent: Wednesday, September 01, 2004 10:58 AM > To: [log in to unmask] > Subject: [TN] Cleaning populated boards with Isopropyl > > > Hi Everyone, > > I currently clean SMT stencils in a sink with hot deionized water. I would > like to automate this process (and eliminate the DI water) and have been > looking at cleaners that can do the job. One of them uses Isopropyl Alcohol > with no rinsing. This should work fine for the stencils but occasionally I > also have to clean misprinted boards that may already be populated on one > side, using no-clean solder paste. If I were to use this Isopropyl process > on the misprints, would I be risking reliability of the board? > > Any help would be appreciated. > > Thank you, > Paul Black > Manufacturing Engineer > Kronos > E-mail: [log in to unmask] > Voice: (978) 947-1520 > > > --------------------------------------------------- > 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 > 847-509-9700 ext.5315 > ----------------------------------------------------- > > --------------------------------------------------- > 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 > 847-509-9700 ext.5315 > ----------------------------------------------------- > > --------------------------------------------------- > 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 847-509-9700 ext.5315 > ----------------------------------------------------- > --------------------------------------------------- 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 847-509-9700 ext.5315 -----------------------------------------------------