The authoritative public forum
  for Metal Finishing since 1989
-----

Factors Affecting Stripping Rate of Dry Film

Hi,

I would like to ask what are the factors attributing to the incomplete stripping of thick dry film (on copper substrate); we are using about 1.5 %KOH for stripping.

Does the conc. of OH affecting the power or any other factors such as the cleanliness of substrate before laminations?

Thanks. in advance

Eric Lam

Eric Lam
- China
2000

---

Dear Eric,

There are several factors for stripping dry resist for example temperature, spray pressure and the make up of your solution. You should have a data sheet for your resist, where all parameters are described. If you do not have one get one. Good luck Marcus

Marcus Hahn
- Sachseln Switzerland
2000

---

The KOH conc. mainly affects the size of the resist skins formed. Incomplete stripping can be due to a lot of factors; temperature being one of the most important. You don't say if you are stripping in a tank or a conveyor, and you don't mention the possibility of overplating locking in resist chips between traces. These areas are just a few of the possibilities.

James Totter, CEF
- Tallahassee, Florida
2000