This time I'd agree Pumpkin ;
cover sheet is neat idea .
When it gets trickier, Matthias could use one of the camelot's (understand
why you prefer simpler toys: any silver epilogue?) dam and fill dispensers,
and drive latex cartridge (nice in line process) around .
Than peel it off upon reflow exit (yes , a robot can to that too (with
needle picks under 30 degrees approach, offload under 30 degrees exit over
rotary brush) . The needles have to be flat 45 degrees ground with the low
edge polished as not to scratch pcb .
Validate the processes Matthias , every way may have different merits ;
the covers are likely to be best solution (if you can go that way),
Inge's apprehension to soiling the pads is understandable .
cu2
paul klasek
ResMed
-----Original Message-----
From: Ingemar Hernefjord (EMW)
[mailto:[log in to unmask]]
Sent: Wednesday, 6 October 1999 23:02
To: [log in to unmask]
Subject: Re: [TN] Wire(?) Bonding, was: Re: [TN] Temporary Solder Mask
Hi Matthias,
don't use anything "wet" or "chemical" or "plastic" on the bond pads! There
will be a powerful reaction from jk or Mike F or worse..from Aussilek! We
have exactly your wonderings in a line just now, to protect bond pads from
flux splatting around during oven process. We simply let the robot drop a
plastic cover down, because all bondings are concentrated to one area. After
oven soldering, the cover is lifted away. If your bond pads are spread out,
of course this method doesn't work. May I ask what kind of wire bonding you
aim at? If it's heavy wire bonding it should not be so sensitive to minor
residues, thin gold wire more apt to disasters then. In principle, you
should make your process such, that flux is stopped within such ranges that
your bond pads are not involved. Well, to say more is not meaningful, I
don't see your problem with a video camera, hope that comes soon in TechNet.
Cu
Ingemar Hernefjord
Ericsson Microwave Systems
I'm looking for a reliable process to protect wire bonding areas
(mostly immeesion NiAu for Al wire bonding) with something like a
temporary soldermask against any dirt from SMD process, instead of
expensive cleaning processes like plasma...
Thanks, regards
Matthias Mansfeld
-----------------------------------------------
Matthias Mansfeld Elektronik
* Printed Circuit Board Design and Assembly
Am Langhoelzl 11, D-85540 Haar, GERMANY
Phone: +49-89-4620 0937, Fax: +49-89-4620 0938
E-Mail: [log in to unmask]
Internet: http://www.mansfeld-elektronik.de
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