Disk Workpiece Dicing with Uncut Outer Regions
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Solution Overview
Problem
The existing methods for dividing disk-shaped workpieces, such as semiconductor wafers, into rectangular chips often result in chip scattering due to waste chips forming near the outer circumference, which can scratch the upper surface of the workpiece, and previous solutions like enhanced dicing tapes increase costs and man-hours.
Innovation Solution
A method where the cutting blade is rotated to cut from the upper surface to the lower surface, with a cutting fluid supplied, and uncut regions are formed along the outer circumference of the workpiece during the cutting process to prevent waste chip scattering, by not cutting the outer circumference at the end of each division line, thereby reducing the risk of chips falling onto the upper surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dicing tape with an annular portion having large adhesive strength is used to prevent chip scattering, then the reliability of preventing upper surface scratches is improved, but the device complexity and manufacturing cost increase
Solution Approach 1:
The harmful waste chips are removed from the system by adjusting the cutting path to prevent their formation in the first place. The cutting blade is fed to stop before completing the outer circumference cut, extracting the problem of waste chip scattering from the processing system.
Solution Approach 2:
The cutting blade creates uncut regions at the outer circumference before the waste chips can form and scatter. By preemptively stopping the cutting path before completing the outer circumference, the harmful waste chips are prevented from forming in the first place.
2Manufacturing precision
If the outer circumference of the workpiece is fully cut along second division lines, then the manufacturing precision of chip division is improved, but the harmful factor of chip scattering increases
Solution Approach 1:
Instead of completing the full outer circumference cut, the cutting blade performs a partial cut that stops before reaching the starting point. This partial action is sufficient to divide the chips while avoiding the excessive action that would create scattered waste chips.
Solution Approach 2:
The cutting process is segmented into two distinct phases: the first cutting step that fully cuts along first division lines, and the second cutting step that partially cuts along second division lines to create uncut regions. This segmentation allows precise chip division while preventing waste chip formation.
3Shape
If the cutting blade rotates to cut from lower surface to upper surface (up cut), then the cutting fluid flow direction changes, but the chipping size increases
Solution Approach 1:
Instead of using up cut (lower surface to upper surface) which would change the cutting fluid flow direction, the invention uses down cut (upper surface to lower surface) and compensates by creating uncut regions. This inverts the approach: rather than changing flow direction to prevent scattering, it maintains the beneficial down cut and prevents scattering through path adjustment.
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
This method effectively prevents chip scattering and subsequent scratching of the workpiece's upper surface without increasing costs or man-hours, by strategically forming uncut regions along the outer circumference during the cutting process.
Implementation Method 1
a cutting fluid is supplied to the workpiece, so as to reduce the processing heat generated from the cutting blade during cutting
Implementation Method 2
the cutting fluid supplied to the cutting blade sticks to the cutting blade and rotates therewith. Accordingly, in the case of the down cut mentioned above, the cutting fluid flows on the workpiece from the front side toward the back side in the feeding direction of the cutting blade
Data Source
AI summary
A dividing method for a disk-shaped workpiece having a plurality of first division lines and a plurality of second division lines intersecting the first division lines. The workpiece is cut along the first and second division lines by using a cutting blade in a down cut manner as supplying a cutting fluid to the cutting blade, wherein the workpiece is fully cut in a thickness direction thereof to obtain a plurality of chips. The dividing method includes a first cutting step of cutting the workpiece along the first division lines and a second cutting step of cutting the workpiece along the second division lines. In at least the second cutting step, the outer circumference of the workpiece at the cut end of each second division line is not cut to form an uncut region, thereby suppressing the formation of waste chips.