This is on new build? I'd ask the vendor how they plan to confirm their
cleaning process will work. Maybe get some ion chromatography testing
done? (I'd be unhappy to accept Ionograph results for something like this).
Working for a different L-3 division a while back we would on occasion
totally strip a repair & overhaul board to facilitate repairing it, we
would put it through a couple of static (bucket) pre-rinses and then
wash it a couple of times.
Graham Collins
Senior Process Engineer
Sunsel Systems
(902) 444-7867
On 9/14/2018 11:18 AM, Chris Thierolf wrote:
> Humiseal 1A33 UR was applied instead of SR. Vendor suggested removing then re-applying SR conformal coating. If residue is a potential issue as you say then the Silicone will trap the residue on the PCB. This is a problem. I will have to do 100% electrical testing to hopefully rule out this condition.
>
> -----Original Message-----
> From: TechNet <[log in to unmask]> On Behalf Of Bogert, Gerald L (Contractor)
> Sent: Friday, September 14, 2018 9:27 AM
> To: [log in to unmask]
> Subject: [EXT] Re: [TN] Humiseal Stripper 1063
>
> September 14, 2018
>
>
> This chemical stripper gel product should only be used as a last resort for removing Type UR coating when other methods of removal such as grit blast or use of heat are not viable. If the gel is not completely removed or neutralized by cleaning process, it will leave conductive residues that can cause improper circuit card operation.
>
>
> ________________________________
> From: TechNet <[log in to unmask]> on behalf of lduso - Diamond-MT.com <[log in to unmask]>
> Sent: Thursday, September 13, 2018 9:05 PM
> To: [log in to unmask]
> Subject: Re: [TN] Humiseal Stripper 1063
>
> Yes and yes. I have used this many times to remove urethane coating from customers CCAs. It does work but can be dangerous. Success often depends on the coating, the thickness, and how much of the board is uncoated. We try to use the most mild stripper that will get the job done sufficiently.
>
> Is complete removal necessary?
>
> On Thu, Sep 13, 2018, 19:57 Chris Thierolf <[log in to unmask]> wrote:
>
>> Anyone use this on fully assembled PCBs to remove Urethane conformal
>> coating? Any risk to components?
>>
>>
>> Chris Thierolf
>> Principal Engineer, EE
>>
>> L3 Power Distribution - SPD Electrical Systems
>> 13500 Roosevelt Blvd.
>> Philadelphia, PA 19116
>> Ph. 215-698-6390
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