HOMEMADE PCBS

THE GOAL

I am aiming to create my own custom pcbs to use in my electronics projects, both at uni and personally. These pcbs should be one sided (potentially two in the future if nessesary) and provide minimum 1mm resolution traces but ideally lower. I have created the general process but am yet to create a defined board, this will be a job for reading week first semester 2024 uni.

THE PROCESS

The general process is as follows:

- Iron photosensitive film onto copper clad pcb board

- Expose pcb pattern using my UV exposing device (image on left)

- Use 2% caustic soda solution to remove unexposed film

- Etch away the now exposed copper with 20% sodium persulfate. Usually ferric chloride is used and it is more effective but sodium persulfate is safer.

- Remove remaining cured film with acetone

- Apply soldermask liquid and squish down with FEP film to protect surface of curing device

- Cure solder mask pattern and remove excess with IPA