Adding phosphorus as an anti-drossing control can be effective for a few hours until the phosphorus burns out, precisely how long is related to temperature and how much disturbance you give to the pot. At 340 C I would expect the time to be quite short. There are some proprietary alloys claimed to have lower drossing for this type of application. I shouldn't think any organic chemical such as an oil or wax is going to last very long at over 300C. Most likely they will contribute to your dross problem by becoming slag. You could consider nitrogen inerting which will also tend to increase the surface tension of the solder. Placing precise beads of solder on wires is commonly done but not so far as I know by solder pot dunking. Slow blow fuses are a good example of this application and where a degree of precision is required, but you would need to change your technique entirely to do this. Might be worth waiting to see if other Technetter have some ideas before going down that road. Regards Mike Fenner Applications Engineer, European Operations Indium Corporation T: + 44 1908 580 400 M: + 44 7810 526 317 F: + 44 1908 580 411 E: [log in to unmask] W: www.indium.com Leadfree: www.Pb-Free.com -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Jos Groffils Sent: Monday, October 14, 2002 3:06 PM To: [log in to unmask] Subject: [TN] solder deposition by dipping Hello, Maybe this question is not typical Technet-related, but I think I can find some solder-expertise on this forum. By quickly dipping a copperwire of 0.6 mm in a HighMeltingPoint-solderbath (MP=296 -302°C), we succeed to take up 5 to 15 mgr (±1 mm(superscript: 3)) solder at 5 mm from the end of the wire (our target is 10 mgr). Because this is a non-equilibrium process the spread is rather high. Nevertheless we try to improve the reproducability. Important factors which we can control are: temperature and withdrawal speed . Surface tension (influenced by the flux) and viscosity of the solder must be important too but difficult to measure and to influence. I can use any ideas / considerations / information how we can improve the reproducability. some other related questions: -how long works the addition of 100 ppm Phosphor in the solder ? -which could be the influence of eutectic solder (Pb(subscript: 97.5)Sn (subscript: 1)Ag(subscript: 1.5) MP=309°C) versus paste range solder (HMP Pb(subscript: 93.5)Sn(subscript: 5)Ag(subscript: 1.5) MP=296-302°C) on the solidifying and reproducability on the wire? -we use flux to dip the wire and a scraper to evacuate the dross (lot of dross!) on the solderbath-surface, we do not know a soldercover(oil) except the too agressive ammonium-zinc-chlorides; are there alternatives? Bath is operating at 340°C. -are there alternative droplet depositioin techniques: what about droplet deposition by jetting? Feasable? Thanks in advance, Jos ---------------------------------------------------------------------------- ----- Technet Mail List provided as a free 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/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 1.8e 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------