Dave, you may have opened the floodgates with this one...here are my two drops.
SPC (my favorite topic) - the pure number of defects is OK if you are only making one design. I'd be worried that the number of defects (I prefer the term nonconformances) per board may be so low that, according to the formulae, 1 or 2 could give you an "out of control" signal. I'm new to this business myself and plan on tracking contamination levels in the wave solder pot, using individuals charts.
Gaging (also my favorite topic) - make sure you have a good way of defining a defect, consistently applied. Maybe you have one component that is a big problem; could you make some kind of quantitive scale to assign it a soldering figure of merit?
Documentation and work instructions - in my view, must define information and tools needed to do the job, operator maintenance, safety guidelines, operator actions, and quality acceptance criteria (explicit). I keep words to a minimum, avoiding vague "shoulds" and "mays", and use the imperative mood.
Let me know if you would like anything more...
Louis Hart
Quality Assurance Manager
Instrumentation Systems Division
Compunetix, Inc. 412-858-6184
Monroeville, PA 15146
"With the chart on the wall, with the figures published, let's emulate and rouse our enthusiasm in production."
- State Statistical Bureau of the People's Republic of China
----------
From: David Hipp[SMTP:[log in to unmask]]
Sent: Friday, December 03, 1999 2:26 PM
To: [log in to unmask]
Subject: [TN] Soldering/Cleaning Expertise
Hello Techies - We are bringing electronic assembly back into our company
within the next quarter. I will have responsibility for the wave soldering
and cleaning process, and I've never done it before. I LOVE a good
challenge! Background information and our equipment are listed at the end of
the post.
I have saved most of the soldering/cleaning posts since I got on TechNet (~7
months) but I still have a few questions. I know my questions are general,
but I would appreciate your candid responses. Feel free to e-mail me
directly. Thanks for your time and expertise!
1) Is there a seminar/class sponsored by IPC (or anybody for that matter)
that can get me up to speed on what I'll be dealing with? I feel I have a
basic understanding but "I don't know what I don't know".
2) We use SPC extensively here. We were planning to chart solder defects as
the wave soldering result. Is this a good choice? Should we do more than
one? What should we track for cleaning?
3) The old process documentation is dated and very heavy-handed. We want to
start fresh. Are there processes or examples for generating good process
documentation?
4) No capital (yet) available for new/upgraded equipment. What is a good
strategy to maximize our old equipment?
BACKGROUND:
I've been with the company for 17 months. Electronic assembly was farmed out
about five years ago. A changing management and business philosophy now
wants it back in-house.
Our product is single-sided, through hole, with post-wave hand soldering for
wires and such. Board density about 70-80%. Mostly analog, some discrete
digital and one microcontroller-based product. Initial quantity will be
1K-2K boards per year. Manually sprayed-on acrylic conformal coating. Used
in a aircraft prop speed controller mounted inside the cockpit.
My background is in design, then production support engineering.
EQUIPMENT:
Electrovert Microline 250
- adjustable foam fluxer air pressure, conveyor speed, preheaters, solder
temp, and wave height. Has air knife.
Unitdesign ABC-2001 "dishwasher"
Omega Meter 600R
JetClean Agitator
MATERIALS:
Kester Sn63Pb37 bar solder
Kester 197, rosin soldering flux, type RMA
Unitdesign Aquaclean SAO-10A
Isopropohol alcohol
DI water
Regards,
Dave Hipp
Woodward Aircraft Engine Systems
Electrical Production Engineering
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