Denny,
You question about not remaining embedded is a good one, since NMP has  a boiling point of 203C.

Regards,
Bev

-----Original Message-----
From: TechNet <[log in to unmask]> On Behalf Of Dennis Fritz
Sent: Friday, December 6, 2019 9:00 AM
To: [log in to unmask]
Subject: Re: [TN] [External] [TN] Miscellaneous uses of NMP and methylene chloride

Thanks, Doug.    Glad to know there are some remaining uses for either NMP
or methylene chloride still being done.

If any TechNet readers do this re-work, I would like to know your operator protection practices, and how you assure that the stripping solvent does not remain embedded in the assembly as it goes into its intended use.
Again, if you wish to contact me off-line, that would be great Denny Fritz

On Thu, Dec 5, 2019 at 9:21 PM Douglas Pauls <[log in to unmask]> wrote:

> NMP and MeCl are still used for polymer stripping, especially 
> conformal coatings.
>
> *Douglas Pauls *| Principal Materials and Process Engr | Advanced 
> Operations Engineering
>
> *COLLINS AEROSPACE*
>
> 400 Collins Road NE, MS 108-101, Cedar Rapids, IA  52498  USA
>
> *Tel:* +1 319 295 2109 | *Mobile: *+1 319 431 3773
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>
> On Thu, Dec 5, 2019 at 8:36 AM Dennis Fritz <[log in to unmask]> wrote:
>
>> TechNet friends -
>>
>> I am on a short assignment from IPC Government Relations to decide 
>> whether to respond to a US EPA Risk Evaluation on some twenty priority chemicals.
>> My assignment is NMP and methylene chloride.  Kelly Scanlon of IPC 
>> has already spear-headed evaluations of TBBPA for laminate and for 
>> formaldehyde.
>>
>> Anyway, we know of NMP use in the multilayer desmear line as a swellant.
>> We are quantifying the use of NMP to dissolve polyimide (and perhaps 
>> other
>> resins) to be able to coat electronics substrates.
>>
>> What we don't know is whether NMP (CAS number 872-50-4) is used in 
>> other circuit board applications, or used in mixtures for stripping or cleaning
>> electronics.   Can you help?
>>
>> Last, I remember huge amounts of methylene chloride (CAS number 
>> 75-09) being used in the old days of solvent photoresist, but those products are
>> long gone.   Does your now company use methylene chloride, alone or in
>> mixtures - again for stripping or cleaning electronics?
>>
>> If you wish to respond off-line, that is fine with me.
>>
>> Denny Fritz
>> Consultant
>>
>>
>> --
>> Denny Fritz
>> Consultant
>> 812 584 2687
>>
>

--
Denny Fritz
Consultant
812 584 2687