This month we bring to you
some innovative rework and
repair information
including:
On line "Cost of
Rework" calculator for
helping you with "make"
vs "buy" PCB rework and
repair decisions
"PCB Pad and Trace
Repair Adhesive" study
results
A NEW solder tip
rinsing method which
allows you to use the
same soldering tips for
both leaded and
lead-free solders
Information on
lead-free compatible
circuit tracks
Hope to see you at either
the SMTA Wisconsin Assembly
Technology Forum or the
Indiana RoHS event!
Bob Wettermann, President
Cost of Rework
Calculator Goes
On-Line
When determining
actual rework costs,
it is always a good
idea to consult with
your accounting
department. You
should obtain from
them a "fully
burdened overhead"
rate per rework
associate that can
be used as a basis
for your
calculation. Work
with them to obtain
the cost of
equipment and
training. Make sure
that you get a
handle on
damage/scrap, which
in many cases is the
largest single
componant of total
rework cost.
Once you have
calculated the costs
required as inputs
to the cost model,
you can calculate
the costs of a
rework job. BEST
has worked with
a cost accounting
firm to develop and
research national
averages as default
values to this
model.
Use this tool to
help you make
well-informed "make"
vs "buy" decisions
in terms of rework
projects.
Solder "Rinsing"
Technique for Lead
Free Hand Soldering
A new technique
which allows you to
use the SAME
soldering tips in a
mixed alloy
environment has been
confirmed. BEST's
newly developed
"rinsing" technique
allows you to stay
within the RoHS
guidelines for
rework even when
switching between
lead-based and
lead-free solders.
The study, which
measured the
presence of lead on
the tip after
subsequent "rinsings",
found that a (4)
time rinse
sufficiently can
reduce the lead
content to below the
RoHS 0.1% lead by
weight guidelines.
See October's SMT
Global Magazine for
more details..
BEST recently
commissioned a study
on the different
adhesive bonding
systems for circuit
pad and trace
repair. This study
compares the results
of the two main
types of bonding
systems-2 part
resin/hardener and
dry film. In
addition, the
recently formulated
BEST dry film
adhesive strength
was compared against
dry film from
company "C".
Previous studies
have shown that even
under thermal
air-air shock
conditions from
-50șC to 85șC at a
30 minute dwell time
for 200 cycles the
resin- hardener
adhesive system
holds up well. The
same cannot be said
about dry film
bonding systems
where the
reliability of
repaired pads, lands
and traces did not
hold up to such
environmental
conditions. The
variability in the
application of
pressure as well as
the many different
tips needed for the
variety of surfaces
make the results of
the "dry film"
method variable as
well as the process
cumbersome.
The BEST
Circuit Trace Repair
Kit is designed to
meet the quality of
original trace
patterns.
The BEST
PCB circuit trace
repair kit gives you
the tools you need
for fast repair and
modification of
circuit traces.
These materials,
packaged together
and designed by
BEST Inc, allows
you to meet original
PCB quality
standards.
The method for
repairing damaged
circuit traces which
are supplied in this
kit employs the use
of copper circuit
tracks which are
epoxied to the
circuit board. These
replacement
conductors are the
same size as the
original. This IPC-recommended
technique is
preferable to making
circuit repairs with
jumper wires because
it most closely
duplicates the
original fabrication
process.
There are (7)
different circuit
traces included in
this kit making sure
you have the trace
that you need when
you need it. Each of
the traces are BOTH
lead- free and
tin-lead alloy
compatible.
INCREASE YOUR
CHANCES TO WIN NEW
HANDHELD PLAYSTATION
You can
increase
your chances
to win a
brand new
PlayStation
Handheld
game (for
the "kids"
of course!)
when you
refer a new
newsletter
subsriber.
Send
referred
e-mail
subsriber to
: info@solder.net
with "Playstation
Drawing" in
the subject
line.
Drawing to
be held
December
15th, 2005
for all
newsletter
recipients.