Have you considered temporary spot mask? It works okay for chip resistors and capacitors, SOT. Not too good for SOIC, stuff gets stuck under the little legs. > -----Original Message----- > From: TechNet [mailto:[log in to unmask]]On Behalf Of makshuwing > Sent: Tuesday, February 19, 2002 6:18 AM > To: [log in to unmask] > Subject: Re: [TN] High temperature solder wire > > > Hello eter, > > Adhesive dispensing, chip placement, reflow(glue curing), manual > insertion, then wave soldering are our normal processes. After > reflow we sometimes find some mis-aligned chips or missing > components. The area of glue in contact with the surface of the > mis-aligned chip could be less than normal and the adhesion force > is insufficient to protect the chip from dropping off during > wave soldering. Therefore we want to use high temp solder to > solder the mis-aligned chips prior to wave soldering. We know > that we could detach the parts after reflow and hand solder the > parts after the wave soldering but we think adding hi-temp solder > is the simpliest way since there is no detachment process is involved. > > Eric > ----- Original Message ----- > From: "Peter Barton" <[log in to unmask]> > To: <[log in to unmask]> > Sent: Tuesday, February 19, 2002 12:41 AM > Subject: Re: [TN] High temperature solder wire > > > > If you are going to the trouble to hand solder these parts on > why not fit > > them after the wave solder process and just tack them on, > applying a dab of > > rework flux first, then reflowing the solder that will be present on the > > pads? Saves the difficulty of using high temp solder pre-wave, and quite > > likely excessive solder on the joints post wave (the solder in your bath > > will wet to the high temp. joints already made). I have seen a similar > > problem when tack soldering large multi way connectors with high temp. > > solder pre-wave. > > > > Regards, > > > > Peter Barton > > > > ===== Original Message from [log in to unmask] (TechNet E-Mail Forum.) at > > 18/02/02 13:40 > > >Hi all, > > > > > >We are currently using adhesive to glue chips on PCB and then > run the board on reflow oven > > followed by wave soldering. After the reflow process we need to > rework some > > chips occasionally due to chip miss-alignment or missing. To do > the rework > > we have to remove the original glue, re-glue the chips and let > the board go > > through the reflow process again. Now we want to eliminate this loop by > > using hi-temp solder wire (melting point 268-302 degree C) to solder the > > reworked chips without adhesive, then let the reworked board > directly go to > > wave soldering with solder pot temperature around 245 degree C. > > > > > >Has anyone using this method seen problems? > > > > > >Eric > > > > > > ----------------------------------------------------------------------- > > Peter Barton > > > > ACW Technology Ltd > > Dinas Isaf West > > Tonypandy > > Mid Glamorgan. CF40 1XX Wales > > > > Tel: 01443 425200 Fax: 01443 436882 > > > > International Tel : +44 1443 425200 Fax : +44 1443 436882 > > > > E-mail: [log in to unmask] Website/URL: www.acw.co.uk > > > > > ------------------------------------------------------------------ > --------------- > > 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 e-mail to > [log in to unmask]: SET Technet NOMAIL > > To receive ONE mailing per day of all the posts: send e-mail to > [log in to unmask]: SET Technet Digest > > 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 > > > ------------------------------------------------------------------ > --------------- > > > > M!Lj)K iuZy y<+ x > !$ u{.n+zwZ,j > M! T9 _Yh)m {ax `ӓ rzWR > cN Tr :-zjh(Z^+ޯ* M!lzw^ r HDygzN0 > N qxD x)zZʇږ[az, צj)m ǫ*\ 4r 8 > zRy܆*.,)౫p r :r^q j֛jǬ f > ܆+ް^jǯ ȭ y"m > "+m_ߢٟv+bv wf '-)朅&jj+ljƤ*\(;O}M w --------------------------------------------------------------------------------- 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 e-mail to [log in to unmask]: SET Technet NOMAIL To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest 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 ---------------------------------------------------------------------------------