Wafer cutting method, LED chip and light-emitting device

The invention provides a wafer cutting method, an LED chip and a light-emitting device, the wafer cutting method adopts a mode of forward laser scribing, deep laser scribing and back splitting, the ratio of the depth of a groove formed by forward laser scribing to the overall thickness of a wafer ranges from 1: 5 to 1: 2, and the groove can avoid the risk of cutting deviation and reduce the hidden danger of abnormal alignment. Besides, the splitting mode adopts a jump splitting mode, the wafer is firstly divided into a plurality of sub-wafers, and then the sub-wafers are cut in different directions in a mode from the edge to the center, so that the lengths of core particles on the two sides of a splitting stress point are reduced, the wafer can be vertically split along a groove deeply scratched by laser on the front surface after falling down by a chopper, and the splitting efficiency of the wafer is improved. The abnormal appearance rate is reduced, and the yield of chips is improved. 本申请提供一种晶圆切割方法及LED芯片、发光