Diffusion furnace for photovoltaic cell manufacturing

Abstract

The invention relates to the technical field of photovoltaic cell manufacturing, and discloses a diffusion furnace for photovoltaic cell manufacturing. The diffusion furnace comprises a furnace body,a quartz tube is arranged in the furnace body, an inner sealing piece is arranged on the inner wall of the quartz tube, the outer wall of the furnace body is rotatably connected with a furnace door, and the side wall of the furnace body is sleeved with an outer cover. A hoop ring is fixedly connected to the end, connected with the furnace body, of the outer cover, an extrusion piece is arranged between the inner sealing piece and the furnace door, and a one-way air valve is installed on the outer wall of the furnace door. The inner sealing piece plays a role in sealing the tube opening of thequartz tube, gas in the quartz tube is prevented from leaking outwards, heat loss caused by air convection is reduced under the action of the vacuum cavity in the inner sealing piece, and therefore the temperature difference between the tube opening of the quartz tube and the inner cavity of the quartz tube is reduced, and the uniformity of sheet resistance of silicon wafers in the quartz tube isimproved; and the deformation of the inner arc plate at high temperature improves the extrusion force on the inner wall of the quartz tube so that the connecting gap is reduced, and the sealing performance is further improved.

Description

technical field [0001] The invention relates to the technical field of photovoltaic cell manufacturing, in particular to a diffusion furnace for photovoltaic cell manufacturing. Background technique [0002] In the actual production of silicon solar cells, P-type silicon wafers are used, and an N-type layer needs to be formed to obtain a PN junction. This is usually achieved by using phosphorus source diffusion under high temperature conditions. Phosphorus oxychloride (POCl 3 ) Liquid diffusion is a commonly used method, that is, the practical protective gas, through the constant temperature liquid source bottle, brings the impurity source steam into the high-temperature diffusion furnace, and reacts with the surface of the silicon wafer through high-temperature thermal decomposition to reduce the impurity atoms, and Diffusion into the silicon wafer. During the above reaction process, POCl 3 Thermal decomposition reaction with oxygen at high temperature will generate chlor...

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Problems solved by technology

[0004] In view of the deficiencies in the use of the existing diffusion furnace proposed in the background technology, the present invention provides a diffusion furnace for photovoltaic cell manufacturing, which has the advantages of good sealing, gas leakage absorption and gas leakage alarm, and solves the above background Problems of airtightness reduction at high temperature and environmental pollution caused by gas leakage proposed in the technology

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