Wafer Division via Selective Laser Deterioration
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Solution Overview
Problem
Existing wafer dividing methods using laser processing result in warping, cracking, and burrs at the intersections of lattice-patterned dividing lines, reducing the quality of the divided semiconductor or optical device wafers.
Innovation Solution
A method involving the formation of continuous and selective deteriorated layers along the first and second dividing lines using a laser beam, excluding intersections, followed by external force application to divide the wafer accurately along these lines, ensuring linear and precise separation without reaching the perpendicular lines through intersections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a pulse laser beam is applied along all dividing lines including intersections to form deteriorated layers, then the wafer can be divided along the dividing lines, but the dividing lines become zigzag and cause warping, cracks, and burrs at intersections
Solution Approach 1:
The patent extracts and removes the harmful effect of forming deteriorated layers at intersection points by excluding these points from the laser processing path. The laser beam intentionally skips the intersection regions where first and second dividing lines meet, preventing the formation of deteriorated layers at these critical locations, thereby eliminating zigzag divisions, warping, cracks, and burrs while maintaining accurate linear division along the dividing lines.
Solution Approach 2:
The patent applies different processing quality to different regions: along the dividing lines, deteriorated layers are formed to enable clean separation, but at the intersection points, no deteriorated layers are formed to maintain structural integrity. This localized differentiation of processing quality ensures accurate linear division while preventing defects at critical intersection regions.
2Ease of manufacture
If continuous deteriorated layers are formed along lattice-patterned dividing lines, then division can be achieved, but the intersecting lines create zigzag patterns reducing division quality
Solution Approach 1:
The patent removes the harmful zigzag pattern formation by extracting the intersection points from the continuous laser processing path. By skipping these points, the deteriorated layers form only along the linear segments of the dividing lines, maintaining linearity and accuracy while still enabling effective wafer division through the formed deteriorated layers.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method ensures accurate, linear division of wafers along both sets of lines, preventing warping and cracking, thereby enhancing the quality and integrity of the divided semiconductor or optical device chips.
Implementation Method 1
applying a pulse laser beam of an infrared range capable of passing through the wafer from one side of the wafer, with its focal point set to the inside to continuously form a deteriorated layer in the inside of the wafer along the dividing lines
Implementation Method 2
applying a laser beam of a wavelength capable of passing through the wafer along the first dividing lines
Implementation Method 3
dividing the wafer along the first dividing lines where the first deteriorated layer has been formed by exerting external force to the wafer along the first dividing lines
Data Source
AI summary
A method of dividing a wafer which is partitioned by a plurality of first dividing lines extending in a predetermined direction and a plurality of second dividing, lines formed in a direction perpendicular to the plurality of first dividing lines, along the first dividing lines and the second dividing lines, comprising the step of forming a first continuous deteriorated layer in the inside of the wafer along the first dividing lines by applying a laser beam along the first dividing lines; the step of forming a second deteriorated layer in the inside of the wafer along the second dividing lines except for the intersections with the first dividing lines by applying a laser beam along the second dividing lines except for the intersections with the first dividing lines; the step of dividing the wafer along the first dividing lines where the first deteriorated layer has been formed by exerting external force to the wafer along the first dividing lines; and the step of dividing the wafer along the second dividing lines where the second deteriorated layer has been formed by exerting external force to the wafer along the second dividing lines.