The process of manufacturing computerized electronics has been shrouded in mystery for users. One piece of the assembly process uses a soldering oven to bond components onto the PCB, which is the printed circuit board. Solder paste with flux is used to attach the components. This is a four step delicate process. Heat is used, but the degree of heat can never to too high or too low. These ovens are commonly referred to as reflow ovens. There are floor models, and now the desktop reflow oven model can also be purchased for less than six thousand dollars.
The technology used for the soldering ovens is called SMT, surface mount technology. Another term used for the ovens is P&P or pick and place machines. Floor models of soldering ovens take up a significant amount of floor space. They are also roughly ten times as costly as the desktop versions of reflow ovens.
The process is very scientific and really quite amazing. Most of the computerized electronic equipment you use every day was in part manufactured in this manner. As you can imagine, the manufacturing of an electronic device with a PCB is a very precise process that includes the use of robotic technologies such as SMT.
There are four stages to the reflow process. First is the preheat zone, next the thermal soak, then the reflow zone and last the cooling zone. Each zone accomplishes a different purpose. The preheat stage must be sensitive to the maximum slope, the rate at which the heat increases. If heat increase too quickly or too slowly the components could be damaged or the flux will not evaporate sufficiently.
The thermal soak zone is brief, typically only one to two minutes. This stage activates the flux, which is the chemical cleaning agent in the solder paste. The activation of the flux causes oxide reduction on the various component pads and leads. Again, precision is needed to attain the exact temperature. At the end of this zone there should be thermal equilibrium before going into the next zone.
The next stage is the reflow zone. The highest temperature occurs during this stage. Precision still is necessary. As a guideline the rule is that the highest temperature must be 5 degrees C less than the degrees tolerated by the component with the lowest heat tolerance. At this time the solder paste liquefies as it reflows through the PCB and components to achieve metallurgical bonding.
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 brands of ovens manufactured. If you are experienced in the use of these ovens, you are likely equipped to make an informed decision about which brand to purchase. Buyers who are new to the product should do some thoughtful research and consult experienced users of various brands.
The technology used for the soldering ovens is called SMT, surface mount technology. Another term used for the ovens is P&P or pick and place machines. Floor models of soldering ovens take up a significant amount of floor space. They are also roughly ten times as costly as the desktop versions of reflow ovens.
The process is very scientific and really quite amazing. Most of the computerized electronic equipment you use every day was in part manufactured in this manner. As you can imagine, the manufacturing of an electronic device with a PCB is a very precise process that includes the use of robotic technologies such as SMT.
There are four stages to the reflow process. First is the preheat zone, next the thermal soak, then the reflow zone and last the cooling zone. Each zone accomplishes a different purpose. The preheat stage must be sensitive to the maximum slope, the rate at which the heat increases. If heat increase too quickly or too slowly the components could be damaged or the flux will not evaporate sufficiently.
The thermal soak zone is brief, typically only one to two minutes. This stage activates the flux, which is the chemical cleaning agent in the solder paste. The activation of the flux causes oxide reduction on the various component pads and leads. Again, precision is needed to attain the exact temperature. At the end of this zone there should be thermal equilibrium before going into the next zone.
The next stage is the reflow zone. The highest temperature occurs during this stage. Precision still is necessary. As a guideline the rule is that the highest temperature must be 5 degrees C less than the degrees tolerated by the component with the lowest heat tolerance. At this time the solder paste liquefies as it reflows through the PCB and components to achieve metallurgical bonding.
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 brands of ovens manufactured. If you are experienced in the use of these ovens, you are likely equipped to make an informed decision about which brand to purchase. Buyers who are new to the product should do some thoughtful research and consult experienced users of various brands.
About the Author:
If you are looking for the facts regarding a desktop reflow oven, go to the web pages online here today. Additional details are available at http://www.sikama.com now.
0 commentaires:
Enregistrer un commentaire