A few other items you might want to look at ,
1)The durometer and condition of the lamination rolls, they tend to
get hard spots in them over time .
2) Assure the final rinse before dry , has a pH of between 4-7 ,
too acid you will get bad stains , unless you have a really good dryer, too
alkaline and the resist won't stick to the surface.
3) I assume you are using DI water or at least a water with reduced
minerals from City water. I never was successful with Softened water , the
Sodium in the water causes it's own set of problems. the cleaner the water
the less "things" remain when it drys.
4) Try to laminate the dry film within 4 hours of electroless
5) Lastly if everything is great coming off the Electroless line an
after drying they are a uniform "Pinkish" color with no visible stains then
start looking at the preclean in the electrolytic line , and for excessive
gas generation during plating.
I am not sure but I think the REVELATOR solution is the developer.
If so make sure that you have not overdosed the antifoam, and the
concentration, and temperature is held to manufacturers recommendations (
measure the actual sumps , not the equipment readout , just in case ...
A few added hints to add to the great hints you have already
recieved.
good luck
russell.smith @Cibasc.com
----------
From: CIPSA
To: [log in to unmask]
Subject: [TN] RV: Dry film adherence problems
Date: Monday, July 12, 1999 5:22AM
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
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