Grinding method for solar battery germanium substrate slices

Abstract

The invention discloses a grinding method for solar battery germanium substrate slices. The grinding method includes sequentially placing planetary wheels on a lower grinding disc in the clockwise direction to enable the planetary wheels to be meshed with an inner gear ring at the center of the lower grinding disc and an outer gear ring on the peripheral edge of the lower grinding disc, respectively placing germanium substrate slices with the front facing downwards into grooves of the planetary wheels, placing an upper grinding disc to enable the upper grinding disc to cling to the lower grinding disc and the upper surfaces of the planetary wheels, leading grinding liquid into the upper grinding disc, enabling the grinding liquid to flow through a through hole of the upper grinding disc to the germanium substrate slices on the planetary wheels, starting a grinder and conducting a grinding process which is divided into a slight pressing stage, a middle-pressure pressing stage, a lower-pressure pressing state and a grinding stage. Under the effect of the grinding faces of the upper grinding disc and the lower grinding disc and the grinding liquid, the grinding pressure is even, so that the machining quantity of the germanium substrate slices is easy to control, grinding precision is high, and the germanium substrate slice loss rate is 12-15 mum in the grinding process. Compared with manual grinding, the grinding method can control total thickness variation (TTV) to be within 2 mum and roughness to be within 0.8 mum. The grinding efficiency is twice as large as manual grinding efficiency, and the slice breaking rate is 1 / 10 as large as manual grinding slice breaking rate.

Description

technical field [0001] The invention relates to a germanium substrate sheet of a solar cell, in particular to a grinding process for a solar germanium substrate sheet. Background technique [0002] In the production of solar photovoltaic cells, using germanium sheets as energy conversion elements can achieve an energy conversion efficiency of more than 30%. However, the development of solar cells requires an increasing chip area on the one hand, and on the other hand, in order to form a PN junction with good performance, This large-area semiconductor workpiece must also be ground and polished. If these large-area germanium wafers have a better surface roughness, they can obtain higher imaging quality and greatly improve the energy conversion rate. Therefore, there is an urgent need for a The technology meets the needs of germanium wafers in the field of actual production and scientific research. In the process of producing solar germanium substrates, the grinding process is...

AI Technical Summary

Problems solved by technology

Traditional manual grinding uses a template to manually grind the wafer, and because the force applied by individuals cannot be completely consistent, resulting in uneven force on the template, resulting in uneven wafer drop, which is difficult to control, and the TTV of the chip is also relatively low due to uneven force. Poor, which will affect the subsequent polishing, the chip debris rate is very high, and the manual grinding efficiency of manual plate by plate is also very low

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