Electron Electronics encourages OEMs to use inhouse PCB production to add extra value to their business by offering clients rapid product customisation services
Original equipment manufacturers able to reengineer products for individual customers’ needs are at a business advantage. However, one disadvantage is redesigning the PCB to accommodate changes, especially for one-off products. A simple solution is to produce PCBs inhouse for specialist requirements.
Artwork is still produced on the OEM’s CAD system but is printed on laser or ink film. The printer should be set to its darkest settings as a poor print quality can result in PCBs failing QC.
Next, a UV unit exposes the artwork on to a photoresist on pre-sensitised laminate for two to three minutes. After exiting the lightbox, the laminate is placed into a developer solution between 30 to 60 seconds. The developer solution should be at room temperature as over developing a laminate can lead to PCBs failing QC after etching.
The laminate is then washed before placement in a heated (45°C) bubble etch tank of ferric chloride to etch the PCB. The ferric chloride should be agitated via a pump, with the etching process taking between five to 10 minutes. Using a Rota Spray 2 unit, time can be cut to 90 seconds. After etching the laminate should be washed.
The photoresist now needs removing. This is done using a scrub block or a resist stripper solution in a heated (45 to 50°C) tank for two to three minutes. Once the laminate is removed from the stripper solution it should be washed and dried. It is recommended that a scrub block is then used to ensure the circuit is perfectly clean.
The final process is immersing the laminate in a tin plate solution for seven to 15 minutes. This prevents the copper laminate oxidising and enhances solderability. This process is carried out at 20°C. After washing and drying the laminate, the PCB can be drilled before component population.