Expansion Tape Substrate Dividing for Complete Small-Chip Separation
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Solution Overview
Problem
Existing substrate dividing methods using expanding tape often result in undivided regions, especially when the chips are small, due to insufficient expansion of the streets.
Innovation Solution
A substrate dividing method that involves forming modified layers as division start points, attaching an expanding tape, and then extending cracks from these layers while the substrate sinks into a gap formed between the holding table and a protective sheet, followed by expanding the tape to widen chip intervals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the expanding tape is expanded to divide the substrate into chips, then the chip intervals are widened, but undivided regions may be generated at the streets when chips are small in size
Solution Approach 1:
The patent applies preliminary action by forming modified layers at the streets before the expanding tape expansion process. These modified layers serve as pre-prepared division start points that guide crack formation during subsequent expansion, ensuring complete division even when chip intervals are small. The preliminary modification of the substrate structure at target division lines enables reliable crack initiation and propagation throughout the expansion process.
2Productivity
If the number of streets is large for small chips, then more division lines are created, but the amount of expansion of individual streets becomes insufficient
Solution Approach 1:
The patent applies local quality by creating modified layers with different physical properties at the street locations compared to the chip regions. The modified layers have altered structural characteristics that make them more susceptible to crack formation and propagation. This localized modification ensures that even when individual street expansion amounts are small due to high chip density, the modified regions still serve as effective division start points, maintaining manufacturing precision across all streets.
3Reliability
If cracks are formed to serve as division start points, then division is initiated, but undivided regions may still occur at streets during expansion
Solution Approach 1:
The patent uses preliminary action by forming modified layers at all street locations before expansion, ensuring that division start points are pre-established throughout the substrate. This preliminary modification creates a network of predetermined crack initiation sites that guide complete division during expansion, preventing undivided regions even when expansion forces vary across different street locations.
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 securely divides the substrate into chips by ensuring sufficient expansion of the chip intervals, thereby reducing the likelihood of undivided regions.
Implementation Method 1
the protective sheet side is held under suction on a holding table
Implementation Method 2
bringing the roller into contact with the expanding tape and rolling the roller, in a state in which a slight gap is formed between a holding surface of the holding table and the protective sheet, and, while causing the substrate to sink into the gap through the protective sheet with the division start points as starting points, extending cracks
Implementation Method 3
expanding the expanding tape to widen intervals of a plurality of chips with the division start points as starting points
Implementation Method 4
applying a laser beam of such a wavelength as to be transmitted through the substrate in a state in which a focal point of the laser beam is positioned inside the substrate, and forming modified layers to be the division start points inside the substrate
Implementation Method 5
grinding the back surface side of the substrate
Data Source
AI summary
A substrate dividing method includes preparing a substrate that is formed with division start points along streets and that has a protective sheet attached to a surface on one side thereof and rolling a roller on a surface on the other side of the substrate, to attach an expanding tape. Next, suction by a holding table is cancelled, and, in a state in which a slight gap is formed between a holding surface of the holding table and the protective sheet, the roller is brought into contact with the expanding tape and rolled, thereby extending cracks extending from the division start points while causing the substrate to sink into the gap through the protective sheet with the division start points as starting points, and the expanding tape is expanded to widen the chip intervals with the division start points as starting points.