Thermal transfer paper for circuit boards

Nowadays, more and more electronics enthusiasts own computers, and using computer software to design PCB diagrams is fast and beautiful. Designers can design any printed board diagram by dragging the mouse, eliminating the tedious processes of engraving, drawing, and tracing. However, it still takes a lot of work to make a satisfactory design into a circuit on a copper-clad board. After repeated experiments, the author finally transferred the PCB diagram printed on thermal transfer paper by a laser printer to the copper-clad board with an electric iron. The transfer effect is the same as that of professional plate making. The thinnest line can reach 0.15mm, and the resolution is more than 1000 lines. The transferred graphics are uniform, firm, and corrosion-resistant. This method is used to transfer graphics and texts to various metal plates sprayed with self-painted paint, and exquisite instrument panels are made. The main cost is only the transfer paper.

Specific operation steps:

Print drawings: Print (or copy) the designed printed board diagram or text on the smooth surface of the transfer paper with a laser printer. Print the graphics on the soldering surface of the circuit board directly, and print the component surface and character surface after flipping 180 degrees: make the spray-painted panel and the embossed panel flip 180 degrees before printing; flip the concave panel 180 degrees and then print it. Do not fold, touch or scratch the transfer paper after printing.

Printing board pretreatment: Use a copper wire brush, degreasing powder, etc. to degrease, polish and clean the rust-free copper-clad plate or thin metal plate. 3) Set the electric iron of 500 watts or more to the “cotton wool” position. After the temperature stabilizes, overlap the prepared transfer paper graphic surface with the copper foil surface of the copper-clad plate, and heat the transfer paper with an electric iron. Move the electric iron slowly according to the size of the transfer area until the entire transfer is completed. After the copper-clad plate that has been transferred returns to normal temperature, gently peel off the transfer paper to make the circuit board to be corroded. After the etching and punching is completed, wipe off the toner on the circuit board and transfer the character side in the same way.

Double-sided circuit board production: first transfer any side of the double-sided board according to the single-sided board production method, and then seal the other side with transparent tape. After etching, peel off the transparent tape, wipe off the graphic toner, and punch the positioning hole. After the positioning is determined, transfer and etch the other side according to the above method (prevent scratches on the back during etching).

Panel production: Concave and convex character panels use thin copper plates. After transfer, seal the back with transparent tape and then etch. The production method is the same as that of single-sided panels. For spray-painted panels, any thin metal plate can be used. After spraying with a suitable color of self-spray paint on one side and drying, align the printed transfer paper graphic surface with the spray-painted surface, and use an electric iron to transfer, and print a black character panel with the sprayed paint as the base color. For the first test, you can cut the printed transfer paper into small strips to master the technique and effect. Be sure to wait until the copper plate cools down before gently lifting the transfer paper; if the transfer paper is not completely lifted and there is a leak, gently put the transfer paper back and heat it with an iron again. Do not rush manual operation, and slowly adapt to it. After adaptation, you can operate on a large area.

Notes:

After transfer, if there are defects on the printing plate, you can use an oil-based marker or nail polish to repair it. When the ambient temperature is too low, you can use an electric iron to preheat the copper plate before transferring, which will have a better effect. The graphic toner transferred on the printing plate can be cleaned with gasoline. Transfer paper is for one-time use and cannot be reused.