Solder Paste Operation: How to Choose the Most Suitable Valve

In the electronics manufacturing industry, the operation of dispensing solder paste is a key step in surface mount technology (SMT), which directly relates to the soldering quality of the circuit board and the reliability of the product. The solder paste valve, as the core component of the dispensing system, is crucial in its selection. A suitable solder paste valve can not only improve production efficiency but also ensure the accuracy and consistency of the dispensing. This article will explore how to choose the most suitable valve for solder paste dispensing operations, analyzing various aspects such as valve types, performance parameters, and application scenarios.

#### 1. Understanding the Basic Types of Solder Paste Valves

Solder paste valves are mainly divided into three categories: screw valves, jet valves, and piston valves.

**1. Screw Valve**

The screw valve precisely controls the extrusion amount of solder paste by rotating the screw. This type of valve is suitable for high-precision, small-volume applications, such as dispensing solder paste for tiny components like 01005. The advantages of the screw valve lie in its high precision and repeatability, but the operating speed is relatively slow, making it suitable for situations where the dispensing speed is not highly demanding.

**2. Jet Valve**

The jet valve uses air pressure to spray solder paste at high speed and in short pulses to the target position. This type of valve is suitable for large-area, fast dispensing applications, such as dispensing solder paste for packaged components like BGA and CSP. The advantages of the jet valve are its high speed and efficiency, but it has higher requirements for the viscosity and fluidity of the solder paste.

**3. Piston Valve**

The piston valve controls the extrusion of solder paste through the reciprocating motion of the piston. This type of valve is suitable for medium-precision, medium-speed dispensing applications, such as dispensing solder paste for components like QFP and SOP. The piston valve achieves a good balance between precision and speed, making it a more versatile choice.

#### 2. Considering Performance Parameters

When selecting a solder paste valve, attention should be paid to the following key performance parameters:

**1. Precision**

Precision is an important indicator of the accuracy of solder paste dispensing. Choose an appropriate precision range based on application requirements. For applications with high precision requirements, such as 01005 components, a screw valve or high-precision piston valve should be selected.

**2. Speed**

Speed determines production efficiency. The jet valve, with its high-speed dispensing capability, is suitable for large-scale, fast production applications. For medium and small batch production, the speed of the piston valve or screw valve is sufficient to meet the needs.

**3. Repeatability**

Repeatability refers to the ability of the solder paste valve to maintain consistency in dispensing volume during continuous dispensing processes. For applications requiring high consistency, a valve with high repeatability should be selected.

**4. Applicable Solder Paste Types**

Different solder pastes have varying characteristics such as viscosity and fluidity, and the adaptability of the valve to the solder paste should be considered when selecting a valve. For example, the jet valve is more suitable for low-viscosity, high-fluidity solder paste.