PCB News - Knowledge points of PCBA rework

Knowledge points of PCBA rework
No matter what we do, repairing is a very troublesome thing; and repairing in the electronics industry is bad news for PCBA manufacturers. It also proves that there is a problem with product quality or that it cannot be directly repaired. Products for customers. Then we need to know what conditions need to be repaired. Today, Baiqiancheng Electronics will talk to you about the relevant knowledge points of PCBA repair, including the purpose of the repair process, what are the process requirements for repair, and the precautions for repair.

Talk about the relevant knowledge points of PCBA rework

1. The purpose of PCBA rework process

1. Generally, after reflow soldering, there will be some defects in solder joints, such as continuous soldering, virtual soldering, less soldering, and more soldering. It is necessary to remove various solder joint defects after trimming, so as to obtain qualified PCBA solder joints.

2. BGA soldering is poor, BGA and IC are relatively precise devices, and it will be more troublesome if there is a defect. And it needs BGA rework station, X-ray and other auxiliary processing.

3. After the guest-supplied materials are pasted without inspection, there will be quality problems, and the materials need to be replaced.

4. After burning and aging tests and debugging, some products have problems. At this time, there are also some components that need to be replaced.

5. After PCBA leaves the factory, because many products are assembled by jigsaw, some problems will arise when a board is taken back for assembly and testing. There will also be some problems during logistics and transportation, which also needs to be repaired.

2. What are the process requirements for PCBA rework

Many times SMT patch factories are reluctant to do repairs, because it is not only time-consuming and labor-intensive, but also requires skills and methods to remove the attached devices. After all, it is not a bare board that can be moved at will, and sometimes even repair problems occur. More. Pay special attention to when disassembling SMD devices, you should wait until all the pins are completely melted before removing the device to prevent damage to the coplanarity of the device and cause loss of the device.

3. Precautions for PCBA rework

1. The PCB pads are very fragile. Do not damage the pads when repairing and disassembling the device, which will cause the entire board to be scrapped.

2. The availability of components. Many customers purchase materials according to the amount. If it is double-sided welding, a component needs to be heated twice, and in addition, it is necessary to consider whether the device can be used again after the furnace is welded again. Therefore, for high-reliability products, it is possible to repair components that are no longer in use once, otherwise reliability problems will occur, and the Fed will delay a lot of time.

3. After the repair, the flatness of the component surface and the PCB circuit board panel must also be maintained, so that problems such as PCB warping cannot appear during the repair.

4. Repeated repairs and operations will generate unnecessary static electricity, so pay attention to the number of potential electrostatic discharge (ESD) hazards.

5. After repairing, you need to re-soldering and adjust the temperature curve of reflow soldering and wave soldering in accordance with the process instructions of the customer's product, so that the overall quality of PCBA is stable.

We share the purpose of PCBA rework process, what are the process requirements for PCBA rework, and what needs to be paid attention to in the rework. This is the relevant knowledge points about PCBA rework that we will share for you. If you still have some questions about rework, you can discuss and solve it together with us!