In the last post, I showed the entire process of etching the photo resist layer. Now what’s left of the photo resist layer (green in colour) is the actual PCB layout.
Beneath the photo resist layer is the copper layer and from the picture above, they are still intact. Our aim is to actually get rid of the copper layers that are not covered with the photo resist layer. Any copper that is hidden below the photo resist layer will remain intact in the etching process.
I bought this bottle of ferric chloride etchant for only RM 6.
It’s pretty concentrated so a small amount would suffice. Always use a plastic container because this stuff is corrosive.
Dipped the whole board into the solution and the whole process took about 20 minutes. It took so long because I did not heat up the etchant. The trick of doing this properly is to leave it for 4-5 minutes and then agitate it for 30 seconds and then repeat the process again and again till all the copper layers are etched away.
This is how it looks like when the process is complete. All of the unwanted copper areas are gone and now what’s left are those hiding below the photo resist layer.
I tried to wash it off with water but it didn’t work. So I went to a pharmacy to get this.
The pharmacy guy looked at me suspiciously and asked me what do I want to do with it. If I told him that it’s for my electronic project sure it’ll take some explanation. I just told him that I need to fill up my first aid kit lol.
By the way those swabs are soaked with rubbing alcohol and they’re exactly what I needed. The box contains 100 swabs and it costs RM 6. And it really works.
The board with all of its copper glory.
That’s it for Part 2. In Part 3, I’ll be posting the final steps in making this board an Arduino Prototype Shield.
In the mean time, here’s a teaser for you all. Try and guess what I’ll be doing and post it in the comments section below.
Thank you 🙂
Part 3 is up. Read it here.