How To Choose The Right Reflow Soldering Equipment?

Selecting the appropriate reflow soldering equipment requires a comprehensive consideration of production requirements, technical characteristics, quality control, and cost-effectiveness. The following are key selection criteria and corresponding reference guidelines:

‌1. Production Requirement Assessment‌

Product Size and Production Capacity‌

Select equipment based on the maximum width of the PCB: For widths >400mm, large-scale equipment is required (conveyor belt width 550mm); for 200-400mm, medium-sized equipment (conveyor belt 400mm); for <200mm, small-scale equipment (e.g., 5-zone) can be selected.

Daily production >5,000 pieces requires a ten-zone large-scale device; 2,000–5,000 pieces selects an eight-zone medium-sized device; <2,000 pieces can select a six-zone small-scale device.

Process Complexity‌

Includes BGA, fine-pitch components, etc., requiring high-precision temperature control (±1°C), recommending a 12-zone device; simple assembly can select an economical model (5–6 zones).

II. Core Technical Parameters

Temperature Zones and Temperature Control Capability

At least 4 independent temperature control zones are required; 8–12 temperature zones are recommended for complex processes [6][14]. Independent temperature control of upper and lower heaters can optimise soldering uniformity.

The measured temperature difference under full load should be ≤±3℃ (ideal value ±1℃), and the temperature difference under no load should be <0.5℃.

Heating Method Comparison

‌Full Hot Air Reflow Soldering: (Advantages) Uniform heating, flexible temperature control (Disadvantages) Prone to component oxidation, may cause component displacement (Application Scenarios) General-purpose production

Infrared + Hot Air Reflow Soldering: (Advantages) Fast thermal compensation, minimal shadow effect (Disadvantages) Higher equipment cost (Application Scenarios) High-precision soldering

Pure Infrared Reflow Soldering: (Advantages) Fast response (Disadvantages) Component colour affects heat absorption efficiency (Application Scenarios) Low-complexity boards

Conveyor Stability

The conveyor belt must operate smoothly (vibration can cause solder joint displacement/cold soldering); the conveyor width must match the PCB size (standard 450 mm).

‌3. Cost and maintenance considerations‌

Initial investment‌

Prioritise cost-effectiveness when budget is limited: small businesses can opt for button-operated + PLC control (lower cost), while multi-product production can choose computer + PLC control (with memory function).

Long-Term Maintenance

Well-known brands offer more reliable after-sales service (e.g., faster response to equipment failures); note the cost of replacing heating elements (e.g., high maintenance costs for hot core board welding).

Special Process Requirements

Nitrogen Protection: When welding precision ICs or requiring high oxidation resistance, a nitrogen interface must be selected.

Cooling Efficiency: High-speed production lines must verify cooling zone performance (to prevent cold soldering).

Summary Recommendations

For small to medium-volume production, choose an 8-zone hot air + infrared device (accurate temperature control, moderate cost);

For large-volume/high-density boards, recommend a 12-zone full hot air device (with nitrogen option);

Before purchasing, be sure to test the temperature difference curve and check the stability of the conveyor belt operation.