new process by using 3 % NaOH

Paul Rissman rissman at stanford.edu
Thu Sep 8 11:42:02 PDT 2005


I agree with Mary.  Don't we need to know what will be etched for disposal 
reasons?

At 11:02 AM 9/8/2005, Mary Tang wrote:
>Hi all --
>
>I think this, in general, sounds OK.  The conditions that would make me
>feel better are:
>
>1.  Waste be collected locally and properly labeled for disposal (this
>sounds like a lift-off process, and as we don't know what the materials
>are, I don't feel comfortable putting it down the AWN.)
>
>2.  Mixing should be done outside the lab.  We should reiterate the
>procedures and policies for transporting chemicals to SNF, especially as
>I'm not sure who this is, much less that he is aware of these policies in
>practice.
>
>How do these sound to you?
>
>Mary
>
>On Thu, 8 Sep 2005, Mr Liangliang Li wrote:
>
> > Dear Sir/Madam:
> >    How are you?
> >    I want to use 3% NaOH solution to strip the resist off from an 8-inch
> > substrate, I hope I can get your permission. the following is the detailed
> > process I want to do on the wet bench general:
> >
> >    1: I will get my own 3% NaOH solution and transfer it into the 
> cleaning room
> > to the wet bench. I will mix NaOH powder with water or dilute 50% NaOH 
> solution
> > outside of the cleanining room, to get 3% solution.
> >    2: I will get a large beaker (9 or 10 inch round size and 6-8 inch 
> tall) and
> > bring it into the cleaning room.
> >    3: one 8-inch Printed circuit board substrate with a mask (made of 
> negative
> > resist) on the top surface will be shipped from Intel. In our own lab, my
> > magnetic material will be deposited to cover the whole substrate. And 
> then, I
> > will bring the substrate to the wet bench.
> >    4: in the wet bench general, I will soak the 8-inch substrate into 
> the 3%
> > NaOH solution inside the big beaker and heat to 45 degree C for 30 
> mins. The
> > resist will be stripped off from the substate.
> >    5: After stripping, I will clean the wet bench and waste accordding 
> to the
> > manual, the 8-inch substate will be taked out of the cleaning room 
> immediately
> > and shipped back to Intel.
> >
> >    In our own lab, I have tested the stability of the substate in 3% NaOH
> > solution at 45 C. It is really stable. The hot plate size is 8 inch by 
> 8 inch
> > and the tank is 11-12 inch size. So we have enough space.
> >
> >    Dear Sir/Madam, if you think this process is ok in the wet bench 
> general,
> > please let me know.
> >    Thank you very much
> >
> > best regards
> > liangliang li
> >




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