Wafer singulating method and led chip and light emitting module

A wafer singulating method comprising:

• providing a wafer product having a front side and a back side opposite to each other, the front side of the wafer product having a plurality of scribe lines;
• deep scribing the wafer product with a laser along the scribe lines from the front side of the wafer product to form a plurality of intersecting trenches on the front side of the wafer product;
• cleaving the back side of the wafer product along the trenches on the front side of the wafer product;
• wherein the cleaving proceeds in different directions each of which is directed to a center of the wafer product from a periphery of the wafer product, and the cleaving in each of the directions proceeds along the trenches one after the other from one of the trenches nearest to the periphery of the wafer product and ceases near or at the center of the wafer product;
• wherein a ratio of a depth of the trench to a thickness of the wafer product ranges from 1:5 to 1:2;
• and
• wherein the trenches include first and second trenches intersecting each other, the step of cleaving the wafer product includes:
• cleaving the back side of the wafer product along a first straight line that extends in a first direction and that passes through a geometric center of the wafer product, and a second straight line that extends in a second direction and that passes through the geometric center of the wafer product, so that the wafer product is divided into a first sub-wafer, a second sub-wafer, a third sub-wafer, and a fourth sub-wafer which follow one after the other in a clockwise order;
• cleaving the back side of the wafer product along the first trenches that are parallel to the first straight line by proceeding from one of the first trenches nearest to a first side of the periphery of the wafer product to the other one of the first trenches nearest to the first straight line so that each of the first sub-wafer and the fourth sub-wafer is diced to allow separation of cleaved parts in the second direction;
• cleaving the wafer product along the first trenches parallel to the first straight line by proceeding from one of the first trenches nearest to a second side of the periphery of the wafer product to the other one of the first lines nearest to the first straight line so that the second sub-wafer and the third sub-wafer are diced to allow separation of cleaved parts in the second direction, the second side being opposite to the first side along the second direction;
• cleaving the wafer product along the second trenches parallel to the second straight line by proceeding from one of the second trenches nearest to a third side of the periphery of the wafer product to the other one of the second trenches nearest to the second straight line so that the first sub-wafer and the second sub-wafer are diced to allow separation of cleaved parts in the first direction;
• and
• cleaving the wafer product along the second trenches parallel to the second straight line by proceeding from one of the second trenches nearest to a fourth side of the periphery of the wafer product to the other one of the second trenches nearest to the second straight trenches so that the third sub-wafer and the fourth sub-wafer are diced for separation of cleaved parts in the first direction, the third and fourth sides being opposite in the first direction.