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
>
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>
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>
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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