Surface Mount Technology (SMT) is a technology of soldering electrical components onto the pre-printed circuit boards. In order to make the whole process possible, SMT reflow soldering oven is usually used. This is a machine that employs high level of technology and bonding principles in its functionality. It is very complex but offers reliability and better alternative in the field of electrical assembly. This comes with advantages such as reduced board cost, controlled manufacturing and assembling process and reduced material handling.
This is one of the machines that get used more often than any other machines in the electrical line of assembly. Before passing over to the oven, the solder paste made of flux, small solder particles and chemical cleaning agents is used to loosely attach the electrical components on to the printed circuit board (PCB) and then sent to the next step.
The beginning point is making of the soldering paste. This is a mixture of flux, some chemical used as cleaning agent and small solder particles. This makes a sticky paste that is used to loosely hold the electronics on to their predetermined positions on the PCB.
The PCB and loosely attached components is then drawn into the heating chambers through a conveyor belt. This then undergoes into four distinct phases in this machine. The first phase is known as preheat zone. This is where the melting point of the solvent is set. The ramp rate (time/temperature rate) is also determined and used to control heating in the following stages.
At thermal soak zone, the components are exposed to heat for about 60-120 seconds. The heat produced at this stage should be enough to remove all the volatiles of solder paste. The reflow zone then takes over. At this stage, the components get exposed to the maximum possible temperature which is normally set a few degrees below the maximum temperature tolerable by the component with the lowest tolerable temperature. This reduces surface tension at joints, the result of which is the bonding between pads and the electronic components.
In the fourth and final zone, the process of cooling takes place. This too is a controlled process. The heating and cooling is such controlled that the PCB and components are not exposed to thermal shock. This is perhaps what makes SMT reflow soldering oven outperform all other methods of bonding.
The oven gets heated by ceramic heaters and heat transfer to the assembly points can be through radiation (hot air) or the infrared electromagnetic radiation depending on the machine make. Other technologies of heat transfer are also used.
They are simpler to operate and work much faster with high accuracy level. They also have higher production level with ability to produce more that 136,000 components in a single hour. Attachment of the components can also be done on both sides at the same time with better electrical efficiency.
The revolution in technology has seen production of better SMT reflow soldering ovens with the latest ones being very efficient in energy consumption, capable of large volume of production thus reducing assembly and handling time and with better quality finished products which all translates to higher profits for the firm and better and safer electronics.
This is one of the machines that get used more often than any other machines in the electrical line of assembly. Before passing over to the oven, the solder paste made of flux, small solder particles and chemical cleaning agents is used to loosely attach the electrical components on to the printed circuit board (PCB) and then sent to the next step.
The beginning point is making of the soldering paste. This is a mixture of flux, some chemical used as cleaning agent and small solder particles. This makes a sticky paste that is used to loosely hold the electronics on to their predetermined positions on the PCB.
The PCB and loosely attached components is then drawn into the heating chambers through a conveyor belt. This then undergoes into four distinct phases in this machine. The first phase is known as preheat zone. This is where the melting point of the solvent is set. The ramp rate (time/temperature rate) is also determined and used to control heating in the following stages.
At thermal soak zone, the components are exposed to heat for about 60-120 seconds. The heat produced at this stage should be enough to remove all the volatiles of solder paste. The reflow zone then takes over. At this stage, the components get exposed to the maximum possible temperature which is normally set a few degrees below the maximum temperature tolerable by the component with the lowest tolerable temperature. This reduces surface tension at joints, the result of which is the bonding between pads and the electronic components.
In the fourth and final zone, the process of cooling takes place. This too is a controlled process. The heating and cooling is such controlled that the PCB and components are not exposed to thermal shock. This is perhaps what makes SMT reflow soldering oven outperform all other methods of bonding.
The oven gets heated by ceramic heaters and heat transfer to the assembly points can be through radiation (hot air) or the infrared electromagnetic radiation depending on the machine make. Other technologies of heat transfer are also used.
They are simpler to operate and work much faster with high accuracy level. They also have higher production level with ability to produce more that 136,000 components in a single hour. Attachment of the components can also be done on both sides at the same time with better electrical efficiency.
The revolution in technology has seen production of better SMT reflow soldering ovens with the latest ones being very efficient in energy consumption, capable of large volume of production thus reducing assembly and handling time and with better quality finished products which all translates to higher profits for the firm and better and safer electronics.
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