Ken,
Don't
know you, but, I like the way you think!
This
is going to be one of our biggest concerns as a CM with a considerable customer
base, some Class 2 and some Class 3.
Right
now, I'm thinking the worst case is if I have some customers with Lead and some
without. Given that situation, not only do we need to keep track of WIP,
but, also RMA material. This means that process sheets will need to be
identified as to which type of solder is used (similar to No-Clean and Water
Soluble). Boards may need to be labeled so as to minimize having to check
the process sheet during processing. Separate solder iron tips will need
to be carefully stored to prevent cross contamination. Maybe separate
benches will need to be set up.
OEM's
who change over don't see the product mix the CM's see, so this will be easier
for them. It will certainly be easiest for the Class 1 folks making my
next Game Boy -- As long as there's an electrical circuit, who cares how long it
lasts....
As far
as Class 3, I'd be REALLY surprised if all of Class 3 was required to transition
to lead free. What does concern me here though is how do we prevent the
no-lead stuff from getting into the lead stuff on the class 3 products!
Again, I think documentation, labeling, checking before soldering, and
segregation of work stations, will be the the best means of preventing a
mix-up. All of which cost $$$$$$.
-Carrie
Hey
Joe, here's another opportunity for you ;-)
In a
recent article from Circuits Assembly Jeff Ferry said, "Cross-contamination is
a real concern". This was in regards to solder iron tips tinned with tin/lead
doing rework on a lead free solder joint or visa versa. Having said that I
have the following question.
How
are companies keeping track of what assemblies were soldered with tin/lead and
those without lead? We all have built tin/lead boards for years but now we are
being forced to switch. When assemblies come back for rework what solder is
the assembler supposed to use? How do they know what the board was soldered
with? What is the "real" effect if the wrong alloy is used to solder an
component? I'm mostly concerned with high reliability Class 3 assemblies but
I'm sure there is something here for other assemblies.
Ken Bloomquist
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