The reflow soldering oven is used for attaching electric components to their contact pad, usually printed circuit boards (PCB) through a reflow process. A mixture of powdered solder and flux (usually sticky) is first used to loosely fix the electrical components on to the PCB which is then subjected to a controlled heat, melting the solder in the process resulting permanent joints.
The oven should be able to heat the adjoining surface melting all the solder into their correct positions without overheating or damaging the electrical components. One or more ceramic infrared heater are used as the source of heat that is then directed to heat the assemblies through radiation process although some ovens(Infrared types) uses fans to direct heat to the assemblies.
A basic reflow oven has four stages through which the operation goes to be complete. The starting point is the preheat zone. This is where the temperature/time rate (ramp rate) is determined. It is the rate at which the temperature of the mounting board and the electrical components on it changes relative to time. This is significant as it helps determine the maximum temperatures possible that can be reached and for how long. The solvent in the mix also starts evaporating at this point.
The PCB is then taken to the thermal soak zone where the removal of solder paste volatiles takes place. Flux activation which involves freeing of leads and pads of any oxide then follows. The temperature range is anywhere between 60 to 120 degrees primary depending on the predetermined ramp rate.
The reflow zone is the third place where the temperatures reaches maximum peak, usually above the liquidus point. The soldering paste is molten under efficiently controlled conditions reducing the surface tension of flux at the point of metal juncture. The result of this process is the permanent fixing of electrical components on to the circuit board. The ramp rate and temperature control is highly significant at this phase. The sudden change of temperatures from the soak zone to above liquidus can easily destroy the devices through temperature shock and thus calls for very efficient control mechanisms.
The last stage is the cooling zone where the circuit board and its component are cooled. This process too is done under efficient temperature control as sudden temperature changes may result to thermal shock. It is also important to avoid excessive metallic formation at this stage as the desired finished circuit board should have components attached with fined grained structured solder making it mechanically sound.
In the modern ovens with the most up to date technology, there is usually no need for solder to flow more than once as these advances techniques guarantees that the granules in the paste can surpass the reflow temperature of the solder used. The trick is therefore to select an oven that can perform optimally at all the phases resulting into the best possible PCB with attached components.
The business environment around us is rapidly changing particularly in regards to the customers, market, technology and competition hence the need to continuously review or operating methods to be sure they are optimal. The best reflow soldering oven guarantees maximum productivity and profitability for assembly firms and other businesses require soldering.
The oven should be able to heat the adjoining surface melting all the solder into their correct positions without overheating or damaging the electrical components. One or more ceramic infrared heater are used as the source of heat that is then directed to heat the assemblies through radiation process although some ovens(Infrared types) uses fans to direct heat to the assemblies.
A basic reflow oven has four stages through which the operation goes to be complete. The starting point is the preheat zone. This is where the temperature/time rate (ramp rate) is determined. It is the rate at which the temperature of the mounting board and the electrical components on it changes relative to time. This is significant as it helps determine the maximum temperatures possible that can be reached and for how long. The solvent in the mix also starts evaporating at this point.
The PCB is then taken to the thermal soak zone where the removal of solder paste volatiles takes place. Flux activation which involves freeing of leads and pads of any oxide then follows. The temperature range is anywhere between 60 to 120 degrees primary depending on the predetermined ramp rate.
The reflow zone is the third place where the temperatures reaches maximum peak, usually above the liquidus point. The soldering paste is molten under efficiently controlled conditions reducing the surface tension of flux at the point of metal juncture. The result of this process is the permanent fixing of electrical components on to the circuit board. The ramp rate and temperature control is highly significant at this phase. The sudden change of temperatures from the soak zone to above liquidus can easily destroy the devices through temperature shock and thus calls for very efficient control mechanisms.
The last stage is the cooling zone where the circuit board and its component are cooled. This process too is done under efficient temperature control as sudden temperature changes may result to thermal shock. It is also important to avoid excessive metallic formation at this stage as the desired finished circuit board should have components attached with fined grained structured solder making it mechanically sound.
In the modern ovens with the most up to date technology, there is usually no need for solder to flow more than once as these advances techniques guarantees that the granules in the paste can surpass the reflow temperature of the solder used. The trick is therefore to select an oven that can perform optimally at all the phases resulting into the best possible PCB with attached components.
The business environment around us is rapidly changing particularly in regards to the customers, market, technology and competition hence the need to continuously review or operating methods to be sure they are optimal. The best reflow soldering oven guarantees maximum productivity and profitability for assembly firms and other businesses require soldering.
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