Seed crystal block applicable to mono-like silicon cast ingot

Abstract

The invention relates to a seed crystal block applicable to a mono-like silicon cast ingot. The seed crystal block comprises a frame seed crystal block abutting against an inner wall on the periphery of a crucible and a plurality of flat-plate seed crystal blocks placed in an area defined by the frame seed crystal block, wherein splicing structures are arranged between every two adjacent flat-plate seed crystal blocks, and the frame seed crystal block comprises a bulge suitable to press upper surfaces of the flat-plate seed crystal blocks from the upper side. The frame seed crystal block comprises the bulge capable of pressing the flat-plate seed crystal blocks, so that the flat-plate seed crystal blocks are fixed and cannot shake after being placed into the crucible; the possibility of warping due to heating of the flat-plate seed crystal blocks is reduced under the extrusion effect of the frame seed crystal block, and the quality of mono-like cast ingot is guaranteed. Besides, by the aid of the frame seed crystal block, the flat-plate seed crystal blocks can be placed in the crucible in a manner closer to horizontal placement, the placed flat-plate seed crystal blocks can be kept horizontal, and a foundation is laid for improvement of the quality of the cast ingot.

Description

technical field [0001] The invention relates to a seed crystal splicing structure for quasi-single crystal silicon ingots, and belongs to the field of silicon crystal manufacturing. Background technique [0002] In recent years, silicon monocrystalline and polycrystalline silicon have been widely used in photovoltaic solar cells, liquid crystal displays and other fields. At present, the common manufacturing method of silicon-like single crystal is the directional solidification method. In this method, cuboid seed crystals are laid on the bottom of the flat-bottomed crucible, and the seed crystals are arranged regularly to form a seed crystal layer. The silicon material is placed in a flat-bottomed crucible and laid on the seed crystal layer. Through the temperature control in the melting stage, after the silicon material is melted, the seed crystal gradually melts from the surface in contact with the silicon liquid, and then the directional growth of the silicon ingot is re...

AI Technical Summary

Problems solved by technology

[0005] However, the inventor has found through experiments that the above-mentioned method still has defects.

Although the bevel splicing structure reduces the generation of gaps to a certain extent, due to the smooth bevel, the seed crystal splicing method may cause deformation of the seed crystal splicing due to pressure during the seed crystal splicing and silicon material filling process, thus affecting the subsequent single crystal ingot casting. quality, put forward high technical requirements for the splicing of seed crystals, and the performance of process tolerance becomes worse

At the same time, during the heating process, the tightly arranged seed crystals may warp due to thermal expansion, and the splicing gap between the seed crystals will become larger, resulting in the proliferation of subsequent crystal dislocations, or the formation of polycrystalline grain boundaries

Images