PCBA refers to the process of mounting, inserting and soldering components on the bare PCB board. The production process of PCBA needs to go through a series of processes to complete the production. This article will introduce the various processes of PCBA production.

The PCBA production process can be divided into several major processes, SMT chip processing → DIP plug-in processing → PCBA testing → finished product assembly.

One. SMT patch processing link

1. According to the customer‘s Gerber file and BOM list, make the process file of SMT production, and generate the SMT coordinate file

2. Check whether all production materials are ready, make a complete set of orders, and confirm the production PMC plan

3. Carry out SMT programming, and make the first board to check to ensure that it is correct

4. According to SMT process, make laser steel mesh

5. Carry out solder paste printing to ensure that the solder paste after printing is uniform, with good thickness and consistency

6. Mount the components on the circuit board through the SMT placement machine, and perform online AOI automatic optical inspection if necessary

7. Set a perfect reflow oven temperature curve, let the circuit board flow through reflow soldering, the solder paste will be transformed from paste, liquid to solid state, and good soldering can be achieved after cooling

8. After necessary IPQC inspection

9. The DIP plug-in process passes the plug-in material through the circuit board and then flows through wave soldering for soldering

10. Necessary post-furnace processes, such as foot cutting, post-welding, board cleaning, etc.

11. QA conducts comprehensive testing to ensure the quality is OK

Two. DIP plug-in processing link

The process of DIP plug-in processing is: plug-in → wave soldering → foot cutting → post-soldering processing → board washing → quality inspection

1. Plugins

Process the pins of the plug-in material and insert it on the PCB board

2. Wave soldering

The inserted board is wave-soldered. During this process, liquid tin will be sprayed onto the PCB board, and finally the soldering will be completed after cooling.

3. Cut feet

The pins of the soldered board are too long and need to be cut.

4. Post welding processing

Hand solder the components with a soldering iron.

5. Wash the board

After wave soldering, the board will be relatively dirty, and it needs to be cleaned with board washing water and board washing tank, or by machine.

6. Quality inspection

Check the PCB board, unqualified products need to be repaired, and qualified products can enter the next process.

Three. PCBA test

PCBA testing is the most critical quality control link in the entire PCBA processing process. It is necessary to strictly follow the PCBA test standards and test the test points of the circuit board according to the customer‘s test plan (Test Plan).

PCBA testing also includes 5 main forms: ICT testing, FCT testing, aging testing, fatigue testing, and testing in harsh environments.

The ICT (In Circuit Test) test mainly includes circuit on-off, voltage and current values ​​and fluctuation curves, amplitude, noise, etc.;

The FCT (Functional Circuit Test) test requires IC program burning, simulates the function of the entire PCBA board, finds problems in hardware and software, and is equipped with necessary production fixtures and test stands;

Burn In Test is mainly to energize the PCBA board and electronic products for a long time, keep them working and observe whether there is any failure. The electronic products after the burn-in test can be sold in batches;

The fatigue test is mainly to sample the PCBA board, and perform high-frequency and long-term operation of the function to observe whether there is any failure, such as continuously clicking the mouse for 100,000 times or turning on and off the LED light 10,000 times, and testing the probability of failure. Feedback the working performance of the PCBA board in the electronic product;

The test under Severe Conditions is mainly to expose the PCBA board to the extreme temperature, humidity, drop, splash, and vibration to obtain the test results of random samples, so as to infer the reliability of the entire PCBA board batch product.

Four. Finished product assembly

Assemble the shell of the tested PCBA board, then test it, and finally it can be shipped.

PCBA production is a chain, and any problems in any link will have a great impact on the overall quality, and each process needs to be strictly controlled.

The above is the introduction of the four major production processes of PCBA.