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Subject:
From:
Yuan-chia Joyce Koo <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Yuan-chia Joyce Koo <[log in to unmask]>
Date:
Mon, 8 Oct 2018 16:47:06 -0400
Content-Type:
text/plain
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text/plain (76 lines)
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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