Why do PCBA circuit boards need glue dispensing sometimes?

Why do PCBA circuit boards need glue dispensing sometimes?

Glue dispensing refers to a process for industrial production of electronIC products, that is, coating, potting, and dripping white glue, UV glue, and red glue onto the products to reinforce, seal, and insulate. The purpose of this is to protect the electronic board and some important electronIC components from moisture, moisture and heat so as to better protect these sensitive components. It can be seen that dispensing not only makes the product quality more stable, but also improves the reputation of the mobile phone brand.

As far as the mobile phone is concerned, the purpose of dispensing between the screen and the frame of the mobile phone is to bond the rear pressing screen and the frame. Accumulation will cause excess glue to overflow or stick to the circuit board, causing potential problems. Leakage of the adhesive will cause gaps between the border and the rear pressing screen, which may cause dust and water stains to soak.

The glue dispensing for mobile phone screen and frame is generally conducted by manual or automatic equipment according to the set coordinate system. The glue dispensing is required to be uniform and good, without accumulation or leakage, and the glue dispensing width should be moderate.

At present, automatic dispensing has greater advantages than manual dispensing. Automatic dispensing can achieve precise dispensing. Many high-precision dispensing that cannot be achieved manually can be achieved accurately through automatic identification and positioning. Compared with manual dispensing, automatic dispensing can avoid errors caused by emotion and fatigue, and can maintain a long time of standardized and standard work. While improving production efficiency, The labor cost of the enterprise is reduced.

When PCBA is being processed, customers often ask PCBA factory whether our products need dispensing process? At this time, we will communicate with customers and judge whether to make dispensing process according to the actual use scenario of the product in the future. Let's talk about what dispensing process is and when it needs to be done.

1. What is dispensing process?

We searched the dispensing process, and we can see the explanation about the dispensing process on Baidu Encyclopedia: dispensing is a process, also known as sizing, coating, glue filling, glue dripping, etc. It is to apply, encapsulate, and drip electronic glue, oil, or other liquids onto the product, so that the product can play the role of pasting, potting, insulation, fixation, surface smoothness, etc. According to the explanation given by Baidu Encyclopedia, we can understand that dispensing process is actually a process to protect products.

2. Why the dispensing process?

Glue dispensing process has two main functions: preventing solder joints from loosening and moisture-proof insulation. Most of the places where dispensing process is required are located in the area with weak structure on the PCB, such as the chip. When the product falls and vibrates, the PCB will vibrate back and forth, and the vibration will be transferred to the solder joint between the chip and PCB, which will cause the solder joint to crack. At this time, gluing really makes the solder joint completely surrounded by glue, reducing the risk of cracking of the solder joint itself. Of course, not all PCBAs will use the dispensing process, because its existence also brings some disadvantages, such as the complexity of the production process, increasing the difficulty of disassembly and repair (it is not easy to remove the chip if it is stuck, and the glue needs to be removed first)

Objectively speaking, dispensing will improve the reliability of the product, which is responsible for the user. Not dispensing can reduce the cost, which is responsible for the user. In the process level, dispensing is not a necessary option, but it can not be done because of cost considerations. However, it is a good way to improve the reliability of the product and avoid potential quality problems, which should be done out of the user's responsibility. Whether to dispense glue or not depends on the actual use of the product.