PCB News - What are the reasons that affect the welding quality of PCB circuit boards?

What are the reasons that affect the welding quality of PCB circuit boards?

Welding is actually a chemical treatment process. The PCB circuit board has problems in the welding process, which will lead to welding defects and deterioration of welding quality, thereby affecting the qualification rate of the circuit board. So, what are the reasons that affect the welding quality of PCB circuit boards?

1. PCB design affects welding quality

PCB size is too large, although the welding is easier to control, but the printed lines are long, the impedance increases, the anti-noise ability is reduced, and the cost increases; if the PCB size is too small, the heat dissipation decreases, the welding is difficult to control, and adjacent lines interfere with each other. Therefore, the PCB board designmust be optimized.

2. The solderability of the circuit board hole affects the welding quality

The so-called solderability refers to the property that the metal surface is wetted by molten solder, that is, a relatively uniform continuous smooth adhesion film is formed on the metal surface where the solder is located. The poor solderability of the circuit board holes will result in false soldering defects, which will affect the parameters of the components in the circuit, resulting in unstable conduction of the components and the inner line, causing the entire circuit to fail.

3. Welding defects caused by warpage

Warpage is often caused by the temperature imbalance of the upper and lower parts of the PCB. PCB and components warp during the welding process, and defects such as virtual welding and short circuit due to stress deformation. When the PCB warps, the components themselves may also warp, and the solder joints located in the center of the components are lifted away from the PCB, resulting in empty soldering. This situation often occurs when only flux is used and no solder paste is used to fill the gap. When using solder paste, due to deformation, the solder paste and the solder ball are connected together to form a short circuit defect.

The above is the analysis of the reasons that affect the quality of PCB circuit board welding. Have you mastered it? iPCB is a high-tech manufacturing enterprise focusing on the development and production of high-precision PCBs. iPCB is happy to be your business partner. Our business goal is to become the most professional prototyping PCB manufacturer in the world. Mainly focus on microwave high frequency PCB, high frequency mixed pressure, ultra-high multi-layer IC testing, from 1+ to 6+ HDI, Anylayer HDI, IC Substrate, IC test board, rigid flexible PCB, ordinary multi-layer FR4 PCB, etc. Products are widely used in industry 4.0, communications, industrial control, digital, power, computers, automobiles, medical, aerospace, instrumentation, Internet of Things and other fields.