Hi Anil,
Well, I see that Roger Hammond was
faster and already sent you a very nice and informative answer. I will try to
contribute my point of view on the process and feel free to ask
further.
I have been running a SHADOW line since 1997
with a machine built by Advanced Chemill Systems.
The pros I have found
are:
Processing time - the metallization takes about 1/4-1/3 of the
electroless time.
Works with much "friendlier" chemicals, although
the graphite (as non-hazardous as it is) makes a lot of mess. You will see a lot
of black spots around (frequent cleaning eliminates most of them) and above
(after a nice accident when the nozzles go spraying around).
From the limited tests that I have done, the end
product does seem to be more reliable than with electroless copper. These tests
are based on thermall stress, thermal cycling + microsections. I also have an
IST test going on, with no results yet.
The process works fine on various
substrates: FR-4, polyimide, PTFE and all kinds of ceramic filled RF
materials.
If you discover after one pass through the machine
that something went wrong - no problem to process again.
Cons:
The process is VERY machine dependent.
Issues such as improper conveyor design or placement of hot air blower close to
the colloid module can be a real pain. It took me a lot to get through the poor
design of my machine and some faults still make my life miserable every day over
and over.
As you understand I am very unhappy with the
company that designed and fabricated the machine. On the other hand I have only
good words on Electrochemicals - good technical responses, frequent and close
contact (mostly on E-mail) and a through desire to amke my process
work.
Good luck with your process,
Yehuda
Weisz
Hi Yehuda,
Shall be grateful if you could mail me your
experience with Shadow Line process.
Thanks in advance.
Anil K Singh
Linaks Microelectronics
Ltd.
India