Element Chip Dicing Groove Roughness to Prevent Grinding Chipping
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Solution Overview
Problem
The existing dicing before grinding (DBG) process for manufacturing element chips, which involves plasma etching and subsequent grinding, often results in chipping due to scallops formed on the side surfaces of grooves during the Bosch process.
Innovation Solution
The proposed method involves a groove forming process that includes a first region with a low surface roughness and a second region with a higher surface roughness, formed using a combination of non-Bosch and Bosch processes. The grinding process is then performed until reaching the first region with low surface roughness, reducing the likelihood of chipping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the Bosch process is used to plasma etch the substrate, then the semiconductor layer is etched perpendicularly to the depth direction, but scallops are formed on the side surfaces of the groove, causing chipping during grinding
Solution Approach 1:
The groove side surface is divided into two regions with different surface roughness characteristics: a first region with low surface roughness and a second region with high surface roughness. The low roughness region is specifically designed to prevent the grinding wheel from catching, thereby eliminating chipping while maintaining the perpendicular etching capability of the Bosch process in the high roughness region.
2Productivity
If the groove side surface has high surface roughness (scallops), then the Bosch process is effective for deep etching, but the grinding wheel catches on the scallops causing chipping
Solution Approach 1:
The groove side surface is segmented into two distinct regions: a first region formed by the Bosch process with high surface roughness that enables efficient deep etching, and a second region with low surface roughness that prevents grinding wheel catching. This segmentation allows each region to fulfill its specific function without compromising the other.
3Ease of manufacture
If grinding is performed on a groove with scallops, then the substrate can be divided into element chips, but portions of the chip are chipped off
Solution Approach 1:
A low surface roughness region is formed on the groove side surface before the grinding process. This preliminary modification of the surface morphology ensures that when grinding is subsequently performed to divide the substrate into element chips, the grinding wheel will not catch on the groove edges, thereby preventing chipping and maintaining chip integrity.
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 effectively inhibits chipping during the DBG process by ensuring that the grinding wheel is less likely to catch on the side surfaces, thereby maintaining the integrity of the element chips.
Implementation Method 1
a method for manufacturing a plurality of element chips by plasma etching a substrate from one surface side thereof
Implementation Method 2
a grinding process of grinding the substrate from the second principal surface side, to divide the substrate into a plurality of element chips
Data Source
AI summary
The element chip manufacturing method includes: a preparing process of preparing a substrate 1 including a plurality of element regions EA and a dividing region DA, the substrate 1 having a first principal surface 1X and a second principal surface 1Y; a groove forming process of forming a groove 13 in the dividing region DA from the first principal surface 1X side; and a grinding process of grinding the substrate 1 from the second principal surface 1Y side, to divide the substrate 1 into a plurality of element chips 20. The groove 13 includes a first region 13a constituted by a side surface having a first surface roughness, and a second region 13b constituted by a side surface having a second surface roughness larger than the first surface roughness. In the grinding process, grinding of the substrate 1 is performed until reaching the first region 13a of the groove 13.