Project 05 · Fabrication process

PCB Photolithography at Home

I turned an MSLA resin 3D printer into a UV exposure unit so I could make my own circuit boards without sending them out to a manufacturer.

Period: June 2025 — Now
Role: Independent engineering project
Tools: MSLA resin printerPhotoresistFeCl₃ etchingDremel

Exposure: Modified MSLA
Develop: NaOH
Etch: FeCl₃
Drill: Dremel

§ 01

The process

An MSLA resin printer already has a UV light source behind a high-resolution LCD mask. I modified one to project circuit trace patterns onto UV-sensitive photoresist film laminated onto copper-clad fiberglass.

After exposure, the board is developed in sodium hydroxide (NaOH) to wash away the unexposed resist, leaving the traces protected.

Fig. 05.01Developed photoresist on copper, first attempt

Fig. 05.02A cleaner exposure with sharper traces

§ 02

Etching & finishing

Ferric chloride (FeCl₃) etches away the exposed copper, then acetone strips the remaining resist. I drilled the component holes with a Dremel rotary tool.

The result is a functional board for my own electronics projects, made in an afternoon at home.

Fig. 05.04V2, with tighter, cleaner traces

Fig. 05.05A homemade board populated with a timer IC and passives

Next project · 06

How 3D-Printed Infill Patterns Affect Vibration