Thursday, December 12, 2013

About SMT Reflow Soldering Oven

By Tiffany Gill


Solder paste is a mixture of flux and powdered solder. The process of attaching electrical components to the contact pads is called reflow soldering. During this process, the controlled heat within SMT reflow soldering oven melts the solder, to connect the joints permanently. Special models are designed to meet high thermal requirements and fine mesh belts for miniature parts.

This method is the most commonly used one when it comes to attaching surface mount components to a circuit board. The biggest advantage of using this method is that the assembly costs are reduced, and the controlled heat doesn't cause damages to electrical components. Typical oven consists of several zones, or stages.

The preheat stage is necessary to activate the soldering paste. When it starts to evaporate, it starts to make the connections in the next heating zone. The third stage is the place when the joints are exposed to the highest temperature. This temperature has to be calculated to avoid damaging the most sensitive electrical components.

The final stage of the process is the cooling zone. Cooling rates are also computer controlled, and they depend on different components. The most commonly used rate is four degrees of Celsius in one second. Although some other devices often ignore this stage, it is proven that it can affect solder joint grain structure.

There are different types of SMT soldering ovens, including medium to high volume models, the ones designed as bench top models, and also nitrogen based. Compared to standard devices designed for the same purpose, they provide lower energy consumption and take up less space. Compact and practical, they can find their usage in different processes.

With at least four independently controlled heating zones, medium to high volume machines are additionally equipped with numerous very useful things, including independent thermocouple inputs. Computer operated and calculated functions make these devices easy to operate and maintain. Smaller devices are often used for prototyping, for example.

The whole process is computer operated and controlled. Parameters can be set automatically, or manually adjusted. The set of parameters can be saved to a memory. Once you reload the saved set, you can adjust individual parameters to suit your present needs. This include specific zone temperature settings and upper and lower limits.

Easy adjustable thermal management and other advanced functions make these devices easy to handle and safe to use. The system includes different alarms, and can be programmed to start up and shut down automatically. The combination of high efficiency, compact size and energy savings makes these models very convenient for all types of industries and for numerous other purposes.

There are also much larger SMT ovens available, designed for high volume manufacturers. These devices can have ten individually controlled heating zones, and process wide boards. All heating zones are computer controlled and equipped with automatic hood-life and high-precision conveyor mechanisms. The device is designed to provide very good stability through all stages and energy-saving thermal heat transfer.

SMT reflow soldering oven is designed to take up less space and to provide excellent results with lower energy consumption. Thanks to efficient pin conveyors, both inline and double sided processing is possible. High quality material is used for all components, to ensure the best performance in high temperature conditions. All devices include battery backup as well.




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