PCB Technical - PCB circuit board production process steps

Briefly describe the steps of the PCB circuit board production process

The design process of printed circuit boards includes schematic design, electronic component database registration, design preparation, block division, electronic component configuration, configuration confirmation, wiring and final inspection. In the process of the process, no matter which process is found to be a problem, it must be returned to the previous process for reconfirmation or correction.

1. Design the schematic diagram according to the function of the circuit. The design of the schematic diagram is mainly based on the electrical performance of each component and the reasonable construction according to the needs. Through the diagram, the important functions of the PCB circuit board and the relationship between the various components can be accurately reflected. The design of the schematic diagram is the first step in the PCB production process, and it is also a very important step. Usually the software used for designing circuit schematics is PROTEl.

2. After the schematic design is completed, each component needs to be packaged through PROTEL to generate and realize the grid with the same appearance and size. After the component package is modified, execute Edit/Set Preferencebrin 1 to set the package reference point at the first pin. Then execute Report/Component Rule check to set all the rules to be checked, and OK. At this point, the package is established.

3. Formally generate PCB. After the network is generated, the position of each component needs to be placed according to the size of the PCB panel. When placing it, it is necessary to ensure that the leads of each component do not cross. After the placement of the components is completed, a DRC check is finally performed to eliminate the pin or lead crossing errors during the wiring of each component. When all the errors are eliminated, a complete PCB design process is completed.

4. Use special carbon paper to print out the designed PCB diagram through an inkjet printer, and then press the side of the printed circuit diagram against the copper plate, and finally put it on the heat exchanger for hot printing. The carbon paper is printed at high temperature. The ink on the circuit diagram is glued to the copper plate.

5. Prepare the board to prepare the solution, mix sulfuric acid and hydrogen peroxide at a ratio of 3:1, and then put the copper plate containing ink stains into it, wait for about three to four minutes, and wait for all parts of the copper plate except the ink stains to be corroded, Remove the copper plate, and then rinse the solution with clean water.

6. Punch holes. Use a hole drill to punch holes on the copper plate where holes are needed. After completion, introduce each matched component into two or more pins from the back of the copper plate, and then use a welding tool to weld the components to the copper plate.

7. After the soldering work is completed, conduct a comprehensive test of the entire circuit board. If there is a problem during the test, you need to determine the location of the problem through the schematic diagram designed in the first step, and then re-sold or replace the components. When the test passes successfully, the entire circuit board is completed.