Martin: Here is a list of issues to consider when selecting a water soluble
temporary solder mask.
It sounds like you currently are using automated dispense equipment. Have
you ever considered screen printing? Cycle time is about 30 secs per panel
and no programming is required. Of course screens need to be made, stored,
cleaned, etc, however depending on the complexity of the deposit and volume
of product it may be worth considering.

1. Method of application: screen print, auto-dispense XY system, hand
application, etc.
Board volume and feature complexity can influence choice of application.

2. Type of material: filled, unfilled, water base, alcohol base etc .
Method of application, type of cure, dissolution rate in wash, type of
washing equipment/chemistry, assembly compatibility SMT-wavesolder-mixed
technology need to be considered for material choice.

3. Board features to be masked: large features, cut-outs, melting metals
etc.
These types of masks usually don't do well over large areas or spanning
cut-outs larger than about 0.300 - 0.400", they can also have a tendency to
flake or crack when used on Sn/Pb when subject to melting temperatures.

4. Applied mask shelflife and storage: masked board storage conditions,
method of storage, hold times prior to use etc. The humidity, how boards are
stored i.e. wrapped-unwrapped-slip sheets-flat stacked-edge stacked, hold
times greater than three to six months can all influence the ability of the
material to perform correctly.



Michael Barmuta

Staff Engineer

Fluke Corp.

Everett WA

425-446-6076


-----Original Message-----
From: Martin Butcher [mailto:[log in to unmask]]
Sent: Wednesday, January 19, 2005 2:44 PM
To: [log in to unmask]
Subject: [TN] Water Soluble Mask Compatible with Automated Dispensing
Systems


Hi All,

In consideration of changing suppliers of water soluble mask, I figured it
would be prudent to ask the industry experts what there experience has
taught them.

My question is, what brand of temporary water soluble mask do you use in
your automated dispensing system?  Other information would be helpful in my
selection.  Facts like drying time, odor, toxicity, ordering lead times,
washability, and disposal.

Your input is appreciated,
Martin Butcher

---------------------------------------------------
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
847-615-7100 ext.2815
-----------------------------------------------------

---------------------------------------------------
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 847-615-7100 ext.2815
-----------------------------------------------------