Teo,
We have 4 MPM-3000 and all have the auto dispense feature. They
work great.
As a general rule, you should never mix old (bad) paste with virgin
paste. The trick is to keep a 5/8 inch diameter roll of paste in front
of the squeegee at all times. This means to add small amount of paste
from the auto dispenser on a frequent basis such as every 30 to 45
minutes. The operators running our lines get lazy over time and drop
one big line of paste on the stencil and then run for 6-8 hours.
With the new solder pastes available today, you should be able
to get a material with a 12 to 24 hour stencil life and then life is
good. The fact that your paste is drying out may be your biggest
concern. Is your environment poor or are you using an older technology
paste that dries out too quickly?
Good Luck
Wade Oberle
[log in to unmask]
-----Original Message-----
From: [log in to unmask]
[SMTP:[log in to unmask]]
Sent: Tuesday, January 19, 1999 10:46 AM
To: [log in to unmask]
Subject: [TN] MPM solder Paste dryness and cartridge
dispenser
Ladies & Gentlemen:
We are currently experiencing a problem in our MPM printing
process.
Often, the solder paste gets dry and leads to product defects.
As a
result, operators dispose the "dry" solder paste. However, the
measure of
"dryness" is very subjective and varies from one operator to
another.
Consequently, our facility is disposing too much solder paste.
Is anybody
measuring the "dryness" of solder paste? If so, how are you
doing this? I
need a scientific way to determine solder paste dryness, and a
guide that
will let me know when the solder paste is no longer good. In
addition, is
there any way to "recycle" dry solder paste? Are there any
solvents or
chemicals that will restore the solder paste to its original
condition?
The solder paste is currently being placed by hand on the
stencil.
Before the stencils are washed, the solder paste is removed and
placed back
into the jar. This results in cross contamination of new and
used paste.
To resolve this cross contamination, we would like to use an
automatic
catridge dispenser which is available with MPM printers. Is
anybody using
these automatic dispensers? If so, do you have any "lessons
learned" or
"recommendations" for using this new equipment?
-Thanks for your help,
Teo Tijerina
Conexant Systems, Inc.
################################################################
TechNet E-Mail Forum provided as a free service by IPC using
LISTSERV 1.8c
################################################################
To subscribe/unsubscribe, send a message to [log in to unmask]
with following text in the body:
To subscribe: SUBSCRIBE TechNet <your full name>
To unsubscribe: SIGNOFF TechNet
################################################################
Please visit IPC's web site (http://www.ipc.org) "On-Line
Services" section for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask]
or 847-509-9700 ext.312
################################################################
################################################################
TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
################################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body:
To subscribe: SUBSCRIBE TechNet <your full name>
To unsubscribe: SIGNOFF TechNet
################################################################
Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################
|
