What are the steps from PCB to PCBA?

Circuit boards are very common in everyday life. It is composed of lead and electronic components. The original meaning is the circuit board of electronic circuit work. We are referred to as “PCB” for short. PCB is just a light board, there is no meta device on it, and PCBA refers to the circuit board plug-in assembly, which means that a PCB board is assembled by the plug-in and becomes a finished circuit board. We can call it the finished circuit board. “PCBA”.

What are the steps  from PCB to PCBA?

We can be divided into several major steps in PCBA production processes, mainly SMT patch processing, DIP plug-in processing, PCBA testing, and finally assembled into finished products.

First, let’s talk about SMT patch processing. The steps of SMT patch processing are divided into seven main steps, namely: tin paste stirring, tin paste printing, SPI detection, sticker, reflux welding, AOI detection, and repair.

1. Stir with tin paste: First take the tin paste out of the refrigerator, and then stir through the natural thawing to print and weld it.

2. Ten paste printing: This step needs to be printed with tin paste. Place the stirred tinpochemical on the steel network and leak the tin paste to the PCB pad by spatula.

3.SPI detection: After the printing machine is printed with PCB, the board will be transferred to the next detection step. SPI is the thickness detector of tin paste, which can detect the printing of tin paste to play the purpose of controlling the effect of tinnum paste.

4. Paste: After the PCB is finished by SPI detection, it will be transmitted to the next working program, that is, the sticker. Patch components are placed on Feida, and the patch head is accurately pasted on the PCB pad by identifying header of the patch.

5. Back welding: Poster PCB plates are transmitted to back welding. After the high temperature in the background welding, the tin paste shaped paste is heated and turned into a liquid, and then the welding is completed by natural cooling solidification.

6.AOI detection: AOI is automatic optical detection. After the PCB completes the welding program, the welding effect of the PCB board can be detected through AOI scanning, and the board defect can be detected.

7. Rebate: Generally, 1-2 people will be placed in the AOI to repair the bad detection of AOI. This can ensure product quality to the greatest extent and prevent bad products from flowing into the terminal link.

Second, the second link to PCBA production is the processing link of the DIP plug-in. DIP plug-in processing process is divided into 6 steps, specifically: plug-in, peak welding, foot cutting, post-welding processing, laundering, and quality inspection.

1. Plug-in: is to process the plug-in material pins and insert them on the PCB board.

2. Peak welding: After completing the the plug-in steps, you need to weld the inserted plate over the peak. In this process, liquid tin will be sprayed on the PCB board, and the welding is also completed by cooling.

3. Foot cutting: To take the steps of welding waves, the pins of the welded board need to be cut for too long.

4. Post welding processing: At this time, ironworkers are required to manually weld the components.

5. Washing: Since the previous welding is performed, the board will be dirty. At this time, you need to use the washing water and basin to clean it, or you can use a machine to clean it.

6. Examination: After completing the previous series of operations, check the PCB board next. If unqualified products are selected for repair, qualified products can enter the next process.

Third, the third major link is the PCBA test. PCBA test can be divided into ICT test, FCT test, aging test and vibration test. The PCBA test is a big test. According to different products, different customer requirements, the test methods used are different. In general, the ICT test is to detect the welding of the component and the entire line, and the FCT test is to detect the input and output parameters of the PCBA board to see if it meets the requirements.

Fourth, after completing the OK PCBA test, the next step is finished product assembly. Test the OK PCBA board for shell assembly, then test it, and then you can ship it.

From the above introduction, we can know that the production process of PCB into PCBA is buckled. In this process, any problems will have a great impact on the overall quality. Strict control is necessary, so the steps of detection/inspection during the production process are essential.