pcb DRY DILM problem

[5282604]

pcb DRY fILM problem

i buy from china negative dry film.
i use soduim carbonate to developing dry film . after developing i see the copper

when i put pcb in ferric chloride to etching it. the pcb is not etching because there are an Transparent layer of dry dry film " i use a correct layer of dry film i know there is 3layer sandwitch". i try all thing and no solve

are the problem in developer ?

 

[pcbfox]

Re: pcb DRY fILM problem

Did you do samples by yourself ?

 

[5282604]

Re: pcb DRY fILM problem

Did you do samples by yourself ?

this photo the pcb in the ferric chloride and the pcb copper not etching and copper still shiny

 

[5282604]

are there problem in dry film ?

 

[marvelpcb]

from the image it shown that you are etching the pads ? and how do you find the "transparent layers"

 

[5282604]

from the image it shown that you are etching the pads ? and how do you find the "transparent layers"

ii have big problem with dry film

i buy from china negative dry film.
i use soduim carbonate to developing dry film . after developing i see the copper good

when i put pcb in ferric chloride to etching it. the some pcb area is not etching because there are an Transparent layer protect copper from etching " i use a correct layer of dry film i know there is 3layer sandwitch". i try all thing and no solve

here is another picture
**broken link removed**