Dear Mr. Varon,
My first impression seems to me you already concluded the problem to be the
dry film adhersion problem. I have to add that there are many other
possibilties that may make the line width "thicker".
1. Poor lamination due to temperature/time/pressure(you have to check the
board surface temp.)
2. Exposure time too short( What is the stouffer?)
3. Developing chemical/spray pressure/time in excess
If it is really "underplated", it is high possible to be problem from point
1 and 3. If it is not underplated, please check point 2.
Hope this help.
____________________________________________________________________________
____________
At 11:22 AM 1999/7/12 +0200, 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
>**********************************************************
>
Albert Mok
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