A reflow oven is used to attach electrical components to a printed circuit board, PCB. This is achieved with the use of solder paste. The process is a delicate balance of heating the solder paste just enough to attach the component or components, but the initial heat cannot be so high that is damages the components or the circuit board. The ovens are now available in the desktop reflow oven model. The prices range from around four to six thousand dollars.
This particular technology is called surface mount technology, or SMT. Sometimes these ovens are called pick and place machines. The floor models of reflow ovens are very expensive and take up a certain amount of floor space. The desktop versions allow for production of small pieces in small places.
The soldering process is highly sophisticated and must be managed with precision. Computerized electronic systems are in many of the products people use every day. Computers, calculators and cars are only a few. Robotic surface mount technology, SMT, is used in manufacturing many of these products.
There are four stages that take place in the reflow oven to achieve the end result of the components being securely soldered onto the PCB. These stages, or zones, are the preheat zone, thermal soak, reflow and cooling zone. During the preheat stage there is heat measurement called the maximum slope. As the preheating temperature rises in 1 to 3 degree C increments the oven must determine the maximum slope, the rate at which the heat can increase without damaging the components or evaporating the flux that is part of the soldering paste.
Less than two minutes, the thermal soak is the shortest stage of this process. This stage activates the flux in the solder paste. The flux is a chemical cleaning agent which when activated creates oxide reduction on the pads and leads of the components. Just the right temperature is needed. If the heat is too low, the flux will not activate fully. Too high heat will cause the solder paste to spatter. At completion, thermal equilibrium must be established.
The third stage, the reflow zone, is when the maximum temperature is reached. The rule is that the peak temperature must be 5 degrees C below the component with the lowest tolerance for heat. During this phase the solder paste is liquid and reflows through the assembly to accomplish metallurgical bonding, the point of the entire process. At this stage precision is required both in terms of temperature and time.
During the fourth and last stage, the cooling zone, the entire assembly will cool and solder joints will become solid. In the previous stage the assembly was at its maximum heat. During this stage it will cool at the rate of about 4 degrees C per second. The PCB and the bonded components are now ready for the next stage of assembly in the manufacturing process.
There are several manufacturers of these soldering ovens. Some people in the market for a desktop model may already have sufficient knowledge of this equipment to make an informed choice. If you do not have the knowledge, talk to other professionals for advice and research at least three different brands before making your purchase.
This particular technology is called surface mount technology, or SMT. Sometimes these ovens are called pick and place machines. The floor models of reflow ovens are very expensive and take up a certain amount of floor space. The desktop versions allow for production of small pieces in small places.
The soldering process is highly sophisticated and must be managed with precision. Computerized electronic systems are in many of the products people use every day. Computers, calculators and cars are only a few. Robotic surface mount technology, SMT, is used in manufacturing many of these products.
There are four stages that take place in the reflow oven to achieve the end result of the components being securely soldered onto the PCB. These stages, or zones, are the preheat zone, thermal soak, reflow and cooling zone. During the preheat stage there is heat measurement called the maximum slope. As the preheating temperature rises in 1 to 3 degree C increments the oven must determine the maximum slope, the rate at which the heat can increase without damaging the components or evaporating the flux that is part of the soldering paste.
Less than two minutes, the thermal soak is the shortest stage of this process. This stage activates the flux in the solder paste. The flux is a chemical cleaning agent which when activated creates oxide reduction on the pads and leads of the components. Just the right temperature is needed. If the heat is too low, the flux will not activate fully. Too high heat will cause the solder paste to spatter. At completion, thermal equilibrium must be established.
The third stage, the reflow zone, is when the maximum temperature is reached. The rule is that the peak temperature must be 5 degrees C below the component with the lowest tolerance for heat. During this phase the solder paste is liquid and reflows through the assembly to accomplish metallurgical bonding, the point of the entire process. At this stage precision is required both in terms of temperature and time.
During the fourth and last stage, the cooling zone, the entire assembly will cool and solder joints will become solid. In the previous stage the assembly was at its maximum heat. During this stage it will cool at the rate of about 4 degrees C per second. The PCB and the bonded components are now ready for the next stage of assembly in the manufacturing process.
There are several manufacturers of these soldering ovens. Some people in the market for a desktop model may already have sufficient knowledge of this equipment to make an informed choice. If you do not have the knowledge, talk to other professionals for advice and research at least three different brands before making your purchase.
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