> CIPSA wrote:
>
>
>
>
> Dear Sirs,
>
> The reason why we send this e-mail is because we are having
> problems of adherence of our dry film Dupont 4615.
> The problem always appears beside the track/pads, and in the final pcb
> you always can see a bigger track, because the adherence of the film has
> not good and some Sn/Pb has get on the base copper (the film has not
> protect correctly the base copper, beside the track).
>
> We have done the following corrective actions and there has not been
> any success at all:
> 1. We have increased the lamination temperature from 105 to 115ºC.
> The presion is about 4 bars. The lamination rolls speed is about 1,6-2 m/min.
> 2. We have checked the pH of the revelator solution and goes from pH
> 11 at the beginnig to 10,4 at the end of the solution live.
> 3. We are quite sure that is not a electrolitic line problem, because in the
> same bath position, we have panels with and without problems.
> 4. We have checked all the insolation parameters and everything is OK.
>
> What we are doing now, is changing from Dupont film 4615, to 215.
> Maybe, it will solve the problem, but we don't know the cause of our problem.
>
> Does anybody knows the cause of our problem ???
>
> Thank you in advance for your colaboration.
>
> Albert Varon
> Quality Manager.
>
>
> **********************************************************
> CIRCUITOS IMPRESOS PROFESIONALES,S.A..
> Pol.Ind.Els Bellots C/de l'Aigua, 28
> 08227 TERRASSA (Barcelona) SPAIN
> Apdo. de correos 597-598
> Telf. 34.937856793 Fax 34.937861905
> **********************************************************

Dear Albert :

It sounds like exposure problem. Probably exposure time for dry film was too
short.
or the film is not proper.
I recommend you to check your exposure time and the film you use (the track width
on the film).
Please correct me if I am wrong!!!!!

Francis