PCB Tech - What are the reliability tests of PCBA processing flow

The PCBA processing process includes project evaluation. When designing products, customers need to design for manufacturability, confirm cooperation, sign contracts, material procurement, inspection and processing, etc. Next, I will introduce the PCBA processing process and reliability testing. ?

1. PCBA processing flow

1. PCBA processing project evaluation, customers have a very important evaluation when designing products: design for manufacturability, which is more critical for quality control of the manufacturing process.

2. Confirm the cooperation and sign the contract. After the negotiation, the two parties decide to cooperate and sign the contract.

3. The customer provides processing information. After the customer completes the product design, he submits the Gerber file, BOM list and other engineering documents to the supplier. The supplier will have a dedicated technician to review, confirm, and evaluate the stencil printing, patch process, and plug-in Process and other details.

4. Material procurement, inspection and processing, customers prepay the cost of PCBA processing to the supplier (ranging from 30% to 100%, generally 70%, the remaining cost is settled before shipment, or 100% prepaid directly.), supply After receiving the payment, the supplier will purchase the components and arrange the production according to the PMC plan after the preparation is complete.

5. SMT patch processing, DIP plug-in processing, material on-line production, quality inspection after SMT patch, reflow soldering, AOI inspection, DIP plug-in and wave soldering processes.

6. Quality inspection by the quality department. The quality department will randomly inspect some products or complete inspections, and repair them if they are found to be defective.

7. Packaging and shipping and after-sales service. All products are packaged and shipped after the quality inspection is completed. The packaging method is generally anti-static packaging. If the customer has special requirements, the packaging will be carried out according to the customer's requirements and the after-sales service will be tracked.

2. PCBA processing reliability test

1. Aging

Place the PCBA board with OK test function under specific temperature and humidity conditions, perform repeated power on and off, simulation function operation, load operation, etc., and check the stability of the PCBA board through 24 to 72 hours of continuous work. Because the aging test takes a long time, it does not have the possibility of large-scale batch operation. In the actual process, the aging test is only a sample test, and the overall yield rate of this batch of products is judged by the qualified rate of the random test.

2. Vibration test

When many PCBA boards are delivered to customers, there are often some problems caused by vibration during transportation, such as component shedding and pad cracks. Through the vibration test, the vibration effect during transportation can be effectively simulated in the laboratory, and the hidden dangers in the welding process are gradually exposed. In this way, batch welding defects are avoided to the greatest extent, and the overall yield rate of delivery is improved. At present, there are professional simulated motion vibration workbenches on the market, and the price is not high, you can purchase one for 5,000 yuan.

3. Surge impact test

In the process of PCBA processing, it is often OK to work under normal voltage, but occasional defects in a certain surge. Many circuit designs are not perfect. They often fail to consider the fatal impact of instantaneous voltage or current impact on the entire circuit. This requires us to conduct sampling surge impact experiments before the mass production of PCBA.

4. Packaging test

This test is often overlooked by everyone, resulting in a very funny problem: We spent a lot of energy to make the PCBA board perfect, but we lost in the last link of packaging and transportation. The factory shall simulate the packaging form of the PCBA board for proper drop test.