How to choose the heat source of rapid annealing furnace?

The rapid annealing furnaces all use iodine tungsten lamps as their heating elements, and the heating speed is very fast. It uses S-type thermocouples for temperature measurement and uses international fuzzy PID for control. Its temperature control accuracy is very high. The rapid annealing furnace has a vacuum device and can work in a variety of atmospheres, which greatly increases the use range of the rapid annealing furnace.

        For the rapid annealing furnace, the choice of heat source is very important, it is related to the quality of the workpiece to be processed, then, what are the heat sources of the rapid annealing furnace? At present, there are two main heat sources used internationally: light heating and high-frequency induction heating. Let's talk to Suzhou Qiao's Annealing Furnace Co., Ltd. to understand these two rapid annealing furnace heat sources.
1. The heating method of lamp heating is composed of two dedicated upper and lower lamp tube groups or single-sided bulbs as the heating source. The shape and number of the heating lamps are determined by the manufacturer and the size of the workpiece to be processed. The silicon chip is located in the double-sided heating lamp. Fast heating is performed in the middle or below the single-sided lamp. Because such a device is a surface light source composed of a linear or point light source, in order to achieve a uniform heating effect, a high requirement for the identity of each lamp tube is required. In theory, the more the number of lights, the more the number of sensors, the drive circuit and the scale of the control system will increase accordingly, and the resulting increase in manufacturing costs, but because of the smaller cavity volume, Achieve a clean atmosphere, reduce contamination, and also reduce thermal budget.

2. High-frequency induction heating

        coils are wound outside the quartz cavity, and parallel graphite heating plates are placed inside the quartz cavity. When a high-frequency voltage is applied to the coil, a high-frequency electromagnetic field will be produced around the coil, and the graphite plate located in the high-frequency alternating electromagnetic field will become a heat source after being induced to generate heat, thereby affecting the cavity The silicon wafer is heat-treated and annealed. In general, although the production and maintenance costs of this method are relatively low, the thermal hysteresis of the graphite plate during induction and the thermal inertia when heating is stopped will slow the temperature control response speed, and the temperature control accuracy is technical The above is not guaranteed, and if high-frequency electromagnetic radiation is improperly controlled, it will easily cause electromagnetic pollution to the surrounding environment.

        The above are the two heat sources of rapid annealing furnace. In these two heat source theories, which heat source should be selected for rapid annealing furnace? In fact, comparing the advantages and disadvantages of the above two heat sources, you can find that if you look at the degree of difficulty of machining, the two are basically the same in terms of quartz cavity, but high-frequency induction heating has to process very thin special shapes. graphite heating plate, the point will be relatively difficult, and many domestic production line, basically using the heating light, so the heating light source selection is more appropriate.

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