Everything you purchase today that is electronic uses circuit boards to keep them running. How these circuit boards are made demands use of complicated specialty equipment designed specifically for making the components for tablets, smart phones and virtually every other electronic devise available. One of the machines needed to create these mobile connections and ensure they work is the reflow soldering oven.
By placing a powdered solder mixture on the circuit board manufacturers can bond two materials. The boards are heated in ovens until the solder becomes liquid and will, when cooled, permanently bind the circuits to the board. To complete the process the boards and circuits must travel through four stages of heat and cooling. These stages are called zones by the manufacturers.
The preheating step is first on the list. This process determines a ramp up rate for the amount of heat that can be applied to the boards in question. When heat is applied too fast it can cause thermal shock to the components or boards. Thermal shock can cause cracking of components or boards and solder paste spattering. Conversely, heating too slow causes the flux in the paste to be incomplete.
A thermal soak zone is next in the process. This soak usually lasts no longer than two minutes and is designed to remove paste volatiles and activate the flux components to begin oxide reduction on leads and pads of circuits. Again the temperature must be precise to prevent spattering or balling of solder from heat that is too high. When the soak is complete a thermal assessment of the entire board is required before it moves to the next zone.
The third step in the process is called the reflow zone. It is also referred to as the time above liquidus or TAL and is the point of highest heat in this process. Operators must monitor the temperature closely in this zone because if it surpasses the level of heat that can be tolerated by the weakest component thermal damage will occur. The entire process lasts about a minute and the solder becomes liquid and "reflows".
Finally the cool down zone where the board gradually cools allowing solder to solidify. Although not as critical as the ramp up process an appropriate cooling process can also help prevent damage to the boards. Specialists recommend a rate of under five degrees per second for cool down.
Having a window to watch the entire process is one of the ways the manufacturer helps the operator. Most of the machines are computerized and can be pre-programmed to do the work without human assistance but being able to see what is happening is important especially on a new run. Many have USB connections so the operators can view them on their computers.
These ovens come in many different sizes. They may range from small units that can be placed on the surface of a bench to units that are longer than six feet. The importance of them is demonstrated everyday in products used to communicate with others as well as for mobile intelligence and gaming. They help to make the world smaller with each new devise they help to create.
By placing a powdered solder mixture on the circuit board manufacturers can bond two materials. The boards are heated in ovens until the solder becomes liquid and will, when cooled, permanently bind the circuits to the board. To complete the process the boards and circuits must travel through four stages of heat and cooling. These stages are called zones by the manufacturers.
The preheating step is first on the list. This process determines a ramp up rate for the amount of heat that can be applied to the boards in question. When heat is applied too fast it can cause thermal shock to the components or boards. Thermal shock can cause cracking of components or boards and solder paste spattering. Conversely, heating too slow causes the flux in the paste to be incomplete.
A thermal soak zone is next in the process. This soak usually lasts no longer than two minutes and is designed to remove paste volatiles and activate the flux components to begin oxide reduction on leads and pads of circuits. Again the temperature must be precise to prevent spattering or balling of solder from heat that is too high. When the soak is complete a thermal assessment of the entire board is required before it moves to the next zone.
The third step in the process is called the reflow zone. It is also referred to as the time above liquidus or TAL and is the point of highest heat in this process. Operators must monitor the temperature closely in this zone because if it surpasses the level of heat that can be tolerated by the weakest component thermal damage will occur. The entire process lasts about a minute and the solder becomes liquid and "reflows".
Finally the cool down zone where the board gradually cools allowing solder to solidify. Although not as critical as the ramp up process an appropriate cooling process can also help prevent damage to the boards. Specialists recommend a rate of under five degrees per second for cool down.
Having a window to watch the entire process is one of the ways the manufacturer helps the operator. Most of the machines are computerized and can be pre-programmed to do the work without human assistance but being able to see what is happening is important especially on a new run. Many have USB connections so the operators can view them on their computers.
These ovens come in many different sizes. They may range from small units that can be placed on the surface of a bench to units that are longer than six feet. The importance of them is demonstrated everyday in products used to communicate with others as well as for mobile intelligence and gaming. They help to make the world smaller with each new devise they help to create.
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