wayne,
agree with your observation. it all depend upon what you use the
tape for. If it is temporary masking, depend upon what is masking
for - prevent contamination of gold wire bonding finger/ electrical
contact, or optical window from flux and cleaning fluid, you might
have problem - there might be residue (depend upon your process)
impact performance. If it is part of assembly (tape will stay on
PWA), depend how good is silicone and how close is to the electrical
contact - there are RISK of silicone migration to adjacent contact
and under some voltage bias condition, will form silica upon
oxidation - cause intermittent or even open on the adjacent contact
- more problem of low voltage application (LCD contact finger for
example). Yes, silicone, some times used as flex - flex guys usually
process at high temp and do it properly, less of concern (more
solvent resistant than acrylic - currently some got acrylic/epoxy
mixture that works better - UV assisted cure also used - two stage,
UV + themal... for those intended to stay with PWA). without
knowing details of application, it is hard to suggest. if it is go
to space, I'll stay with good old kapton that used in clean room
condition (not the silicone or new acrylic gummy).
IMHO.
jk
On Oct 8, 2018, at 4:07 PM, Wayne Thayer wrote:
> The usual alternative to silicone adhesive is acrylic adhesive. I
> tried
> eliminating silicone adhesives years ago when I was running a plating
> operation. The experiment failed dismally:
>
> -There was no evidence the silicone ever caused a problem with de-
> wetting
> or other issues silicone OILS cause--so I did this based on
> principal as
> opposed to practicality!
> -Silicone adhesive for tapes stick best to other silicone, so after
> you
> peel, there is usually no residue at all
> -Acrylic adhesives drop little globs of acrylic all over the place.
> The
> worst offender is the half-sticky stuff such as "Post-It" notes.
>
> Wayne Thayer
>
> On Wed, Oct 3, 2018 at 7:06 AM Vargas, Stephen M
> <[log in to unmask]>
> wrote:
>
>> Good morning all:
>>
>> We are looking to move away from silicone based adhesives
>> with our
>> Kapton tape to a non-silicone based version. It appears as though
>> 3M has a
>> 7419 Series that may be a good option. I'm looking for input from
>> those of
>> you who have switched and would like some recommendation on what
>> has worked
>> well for you. Off-line responses welcome. Thanks.
>>
>> Regards,
>> Steve Vargas
>>
>> If you don't have time to do it right, when will you have time to
>> do it
>> over?
>> John Wooden
>>
>> Polaris Contract Mfg Inc
>> 15 Barnabas Rd
>> Marion, MA 02738
>> 774-553-6192
>> [log in to unmask]<mailto:[log in to unmask]>
>>
>> P Please consider the environment before printing this e-mail
>>
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