How to make high-quality double-sided PCB circuit boards

　　To produce high-quality double-sided PCB circuit boards, it is necessary to go through the entire process of design, board making, assembly, and testing. The core is to control impedance matching, interconnect reliability, and process compatibility, while avoiding common problems such as short circuits, virtual soldering, and signal interference. The specific steps and key points are as follows:

　　1、 Professional self-made (laboratory)

　　Design: Software wiring, line width ≥ 0.3mm, via holes ≥ 0.5mm, adding tears, double-sided copper-clad and fully connected via holes.

　　Plate making: Clean the copper-clad board and transfer the circuit to the copper surface using heat transfer printing or photosensitive method.

　　Etching: Use a heated (40-50 ℃) ferric chloride solution and shake to etch until the circuit is clear.

　　Drilling: The bench drill rotates at high speed and feeds slowly, accurately drilling through all through holes.

　　Through hole connection: Insert hollow copper rivets for compression, or use conductive silver paste to penetrate the hole wall.

　　Welding: Apply rosin flux and use solder to reliably weld.

　　2、 Industrial production (sampling)

　　Design specifications: Design according to the factory's process capability and output standard Gerber files.

　　Key requirements:

　　Board: Specify FR-4 high Tg value

　　Surface treatment: Choose sinking gold (ENIG), smooth and durable

　　Through hole treatment: select plug oil to prevent tin from entering

　　Impedance control: Special instructions are required for high-speed signals

　　Order review: Provide a complete document package and confirm all process requirements.

　　Core difference: Self production relies on manual precision, while industry relies on standardization and craftsmanship. The key to high quality lies in the rationality of design and the precise control of key steps (etching/via).