Metal Burr Removal in Semiconductor Dicing via Oxidation
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Solution Overview
Problem
Existing methods fail to fully remove metal burrs at the intersections of projected dicing lines during the cutting process, leading to potential short circuits and bonding failures due to the malleable nature of these burrs.
Innovation Solution
A method involving a rotating annular cutting blade that forms cut grooves in the workpiece, with a liquid containing an organic acid and an oxidizing agent supplied to modify the metal burrs, making them less malleable and easier to remove, while the blade is positioned to effectively remove burrs from these grooves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a rotating cutting blade is used to cut along projected dicing lines, then the workpiece can be divided into device chips, but metal burrs are generated at intersections of dicing lines
Solution Approach 1:
The patent applies preliminary action by performing a first cutting step along first projected dicing lines before performing a second cutting step along second projected dicing lines. This sequential approach allows metal burrs to be removed after the first cutting direction is completed, preventing burr formation at intersections and eliminating the need for additional burr removal operations.
2Manufacturing precision
If the cutting blade is moved through cut grooves to remove metal burrs, then some burrs can be removed, but burrs at intersections deform toward other dicing lines and remain difficult to remove
Solution Approach 1:
The patent performs preliminary cutting along one set of dicing lines before cutting along the other set, which prevents metal burrs from deforming toward uncut intersections. By establishing cut grooves in advance, subsequent cutting operations can cleanly remove burrs without the deformation problem that occurs when attempting to remove burrs from uncut intersections.
Solution Approach 2:
The patent segments the cutting process into distinct first and second cutting steps performed in sequence along different sets of projected dicing lines. This segmentation allows each cutting direction to be handled independently, with burr removal performed after the first set of cuts is complete, eliminating the interaction problem that causes burr deformation at intersections.
3Reliability
If metal burrs remain on device chips, then short circuits and bonding failures may occur, but removing burrs requires additional processing steps
Solution Approach 1:
The patent incorporates burr removal as a preliminary action immediately following the first cutting step, before the second cutting step is performed. This timing ensures that metal burrs are removed while the workpiece is still in a stable state, preventing short circuits and bonding failures without requiring separate post-processing steps.
Solution Approach 2:
The patent merges the burr removal function with the cutting process by performing burr removal during the transition between cutting steps. Instead of treating burr removal as a separate post-processing operation, it is integrated into the cutting sequence, eliminating additional processing steps while ensuring device chip reliability.
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 approach allows for the efficient removal of metal burrs at intersections, preventing short circuits and bonding failures by rendering the burrs less malleable and facilitating their removal without deformation.
Implementation Method 1
a liquid containing an organic acid and an oxidizing agent is supplied to the workpiece in the first metal burr removing step and the second metal burr removing step
Implementation Method 2
A liquid containing an organic acid and an oxidizing agent is supplied to the workpiece in the first metal burr removing step and the second metal burr removing step
Data Source
AI summary
A method of processing a workpiece with a cutting blade, the workpiece having a body of metal disposed in superposed relation to projected dicing lines, including: a first metal burr removing step of moving the cutting blade through first cut grooves while the cutting blade is positioned at such a height that a lowermost end of the cutting blade is lower than an upper end of the body of metal; and a second metal burr removing step of moving the cutting blade through the second cut grooves while the cutting blade is positioned at such a height that the lowermost end of the cutting blade is lower than the upper end of the body of metal. A liquid containing an organic acid and an oxidizing agent is supplied to the workpiece in the first metal burr removing step and the second metal burr removing step.