Ingemar:
To determine if Marianne's suggestions are correct, in my experience,
the best way would be to perform thermodynamics analysis on the
materials. A thermomechanical analysis (TMA) will tell you Tg, as well
as give a feel if the material is properly cured if the correct
techniques are employed during the analysis. Residual stresses can also
be found using DMA; TGA analysis might be helpful if you have a
hydroscopicity problem causing registration losses...

Regards,
> Bill Davis, Ph.D.
> Diamond Multimedia Systems
> Senior Scientist
> Tel. 408.325.7868
> Cell. 408.888.5650
> e-mail: [log in to unmask]
>
>
>
>
> -----Original Message-----
> From: [log in to unmask]
> [SMTP:[log in to unmask]]
> Sent: Thursday, November 19, 1998 11:43 PM
> To:   [log in to unmask]
> Subject:      Re: [TN] THERMOPLASTIC RELIABILITY
>
> >Thanks for answer, Marianne,
> I will ask the manufacturer as you indicate. Werner Engelmaier is of
> different opinion. He thinks we exaggerate the problem. Huge and heavy
> and complex structures are being built with thermoplastics, and they
> keep adhesion despite hot ambient conditions. Thanks again.//Ingemar
>
> --------------------------------------------------------------------
>  No optimism here.
> >
> >  If the maximum Tg is 75 C, it is quite possible that the beginning
> of
> the
> > glass transition zone is in the 60 C range.  Softening and loss of
> > positional registration can therefore occur.
> >
> > To verify whether this particular product is useable in your
> operating
> > environment, you may want to have the material analyzed to determine
> where
> > the onset of softening occurs, and to ask the supplier for their
> > manufacturing process tolerances on the thermoplastic.  Or run your
> product
> > through reliability testing.
> > ____________________________________________________________
> > Marianne Romansky
> > Process Development Scientist
> > Celestica (Toronto) Inc.
> > Phone: (416) 448-6284
> > Email: [log in to unmask]
> >
>
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