How To Choose The Right Wave Soldering Oven Temperature To Test Equipment?

I. What is Wave Soldering oven?

Wave Soldering oven is a process used for soldering electronic components, mainly used for surface mounted components (SMD) or through-hole components (THT) soldered to PCBs. The process is accomplished by forming a "wave" of molten solder that passes through the PCB, thereby soldering the components.

II. How to choose the right wave soldering oven temperature to test the equipment?

In the preheating zone, the solvents in the flux sprayed on the board are evaporated, which reduces the amount of gas generated during soldering. At the same time, rosin and activator begin to decompose and activate, removing oxidation and other contaminants from the soldering surface and preventing the metal surface from re-oxidizing at high temperatures. Printed circuit boards and components are preheated sufficiently to effectively avoid thermal stress damage caused by the rapid rise in temperature during soldering.

The preheating temperature and time of the circuit board is determined by the size and thickness of the printed circuit board, the size and number of components, and the number of mounted components. Measured on the surface of the PCB preheating temperature should be between 90 ~ 130 ℃, multilayer boards or SMD kits with more components, the preheating temperature to take the upper limit. The preheating time is controlled by the speed of the conveyor belt.

If the preheating temperature is low or the preheating time is too short, the solvent in the flux does not evaporate sufficiently, the soldering will produce gas to cause air holes, tin beads and other soldering defects. If the preheating temperature is high or preheating time is too long, the flux is decomposed in advance, so that the flux is inactive, will also cause burrs, bridging and other welding defects.

In order to properly control the preheating temperature and time, to achieve a good preheating temperature, but also from the wave soldering coated on the bottom surface of the PCB before the flux is sticky to judge.

III. Qualified temperature profile must be met

1. Preheating zone PCB board bottom temperature range: 90-120oC.

2. Soldering tin point temperature range of: 245 ± 10 ℃.

3.CHIP and WAVE between the temperature can not be lower than 180 ℃.

4.PCB dip tin time: 2-5sec.

5. PCB board bottom preheating temperature ramp rate ≦ 5oC / S

6. PCB board temperature control at the exit of the 100 degrees below

The temperature and duration of each zone are also determined by the temperature setting of each zone of the equipment, the temperature of the molten solder and the running speed of the conveyor belt. Wave soldering oven temperature profiling still needs to be determined by means of testing, and the basic process is similar to reflow profiling.

Since the front side of the PCB is generally mounted densely, the temperature profile can only detect the surface temperature. Test, determine the conveyor speed, and then record the temperature of the test board less than three points. Repeatedly adjust the heater temperature value so that the temperature of each point to reach the set curve requirements, and then after the actual test and make the necessary adjustments.

In the preparation of process documents, in addition to record the heating temperature curve setting, generally also need to record the solder and its Xu cloth process parameters (foam height, spray angle, pressure, density control requirements and flux reasoning, etc.), solder wave parameters, solder pick up test and remove slag requirements, etc., which are the main process parameters of the wave soldering.

Features of NeoDen ND250 Wave Soldering Machine

Heating Method: Hot Wind

Cooling method: Axial fan cooling

Transfer Direction: Left→Right

Temperature Control: PID+SSR

Machine Control: Mitsubishi PLC+ Touch Screen

Flux tank capacity: Max 5.2L

Spray Method: Step Motor+ST-6

Specification