Factors Affecting PCBA Wave Soldering Quality

 Wave soldering is a soldering method in the PCBA manufacturing process, mainly used for through-hole technology (THT) and mixed-assembly processes. The final soldering quality during wave soldering is affected by several factors, such as wave soldering equipment, soldering materials, and PCB boards. Below is a detailed explanation.

1. Wave Soldering Equipment Factors

Equipment issues are one of the main factors affecting wave soldering quality, primarily involving the spraying of wave soldering flux, temperature control of temperature zones during soldering, and the stability of the conveyor belt.

For flux spraying: It is essential to clean and replace flux nozzles promptly during wave soldering, and set the flux spraying time appropriately. This prevents uneven flux spraying, which could lead to wave soldering quality problems.

For temperature zone control: Wave soldering systems typically have four temperature zones — preheating zone, temperature-rising zone, high-temperature zone, and cooling zone. Each zone requires specific temperature settings and dwell times. Proper adjustment of these parameters avoids soldering defects like solder splashing.

For conveyor belt stability: A stable conveyor belt ensures consistent contact between PCBs and the solder wave, preventing issues such as uneven soldering caused by PCB deviation.

2. Soldering Material Factors

Materials used in wave soldering include solder, components, and flux. Key considerations for each material are as follows:

Solder: Wave soldering uses solder bars (a key difference from reflow soldering). The composition ratio of solder bars and impurity content directly impact final soldering quality. For example, excessive impurities can cause brittle solder joints or poor wetting.

Flux: Insufficient flux activity reduces solder wetting performance and fails to clean the soldering surface. This ultimately leads to defects such as incomplete solder joints.

Components: The quality of component pins (e.g., plating uniformity) affects soldering compatibility. Low-quality pins may cause poor solder adhesion.

3. Component and PCB Board Factors

Components: Oxidation, oil, or other contaminants on component pins or plating can result in soldering defects like cold joints during the soldering process.

PCB boards: Multiple PCB-related issues can affect soldering quality:

Oxidation on PCB pads reduces solder adhesion.

Poor PCB flatness causes inconsistent contact with the solder wave, leading to uneven soldering.

Moisture absorption due to improper storage results in defects such as solder balls or air bubbles in solder joints.

In addition to the above factors, PCB design (e.g., pad spacing) and production process parameters also directly influence the final wave soldering quality.

If you need more information about PCBA and SMT technologies, please contact Sandy directly at sales9@hitechpcb.com.



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