Multiplex temperature control device for diffusion furnace

Abstract

The invention relates to a multiplex temperature control device for a diffusion furnace. The device is provided with a temperature control thermocouple and a detection thermocouple, wherein the temperature control thermocouple is inserted into the diffusion furnace; and the detection thermocouple is arranged on the outer surface of the furnace wall of the diffusion furnace. The temperature control thermocouple is used for controlling temperature inside and outside the diffusion furnace; the temperature control thermocouple which is inserted into the diffusion furnace can be directly used for setting temperature and intuitively adjusting a process; and the externally connected detection thermocouple can be used for measuring the temperature of the furnace wall of the diffusion furnace and macroscopically detecting whether the set temperature of the diffusion furnace is reached, so that rework of a silicon slice, caused by instable and non-uniform diffusion temperature, can be reduced, and utilization rate of equipment can be increased.

Description

technical field [0001] The invention relates to a solar cell production equipment, in particular to a multi-temperature control device for a diffusion furnace used in the diffusion of solar cells. Background technique [0002] At present, the production process of solar cells mainly includes cleaning, texturing, diffusion, etching, removing PSG, coating, printing electrodes, sintering and classification detection. Among them, the PN junction of the diffusion process is the key to the conversion efficiency of solar cells. The essential. The so-called PN junction is that under the action of high temperature, phosphorus atoms diffuse into the P-type silicon wafer doped with boron and lose electrons to form a positively charged area. At the same time, the thin layer on the surface of the silicon wafer loses holes to form a negatively charged area. In this way, a space charge region with positive and negative charges is formed on both sides of the interface between the N-type re...

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Problems solved by technology

[0003] At present, the general-purpose diffusion furnace is only equipped with an external thermocouple, which can only monitor the temperature of the furnace tube wall, but cannot monitor the actual temperature of the middle of the furnace tube participating in the diffusion reaction, and the temperature of the furnace tube wall is lower than the temperature of the diffusion reaction during the production process. Moreover, the internal temperature is monitored externally, and the induction of temperature fluctuations is delayed, resulting in the inability to monitor the diffusion temperature in a timely and accurate manner.

Diffusion temperature is a major factor affecting the diffusion process. This situation of uncertain whether the diffusion reaches the set temperature will have a great adverse effect on the silicon wafer, equipment and process environment.

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