Semiconductor Die Support Structure for Low-TTV Backside Grinding
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Solution Overview
Problem
The existing semiconductor packaging methods face challenges in reducing package thickness and manufacturing costs while maintaining precise control over the exposure of conductive pillars, as the deformation of the semiconductor die during backside grinding leads to high total thickness variation (TTV) due to the formation of recesses under the tape, especially when the die thickness is below 100 μm.
Innovation Solution
Incorporating a plurality of supporters in the sparse connection region between dense conductive pillar regions, which helps prevent the formation of recesses on the tape and reduces the impact of semiconductor die deformation, thereby minimizing TTV. This is achieved by using mechanical supports or protrusions at the chuck table during vacuum suction to maintain the die's shape during thinning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the semiconductor die thickness is reduced below 100 μm to achieve volume reduction, then package thickness is reduced, but total thickness variation (TTV) increases due to die deformation during backside grinding
Solution Approach 1:
The patent applies preliminary action by forming protrusions on the chuck table surface before the backside grinding process. These protrusions are positioned to contact specific regions of the semiconductor die (sparse connection regions) in advance, providing mechanical support that prevents deformation during subsequent thinning operations. This pre-positioned support structure enables thickness reduction while maintaining TTV control.
Solution Approach 2:
The patent implements local quality by creating non-uniform support structures on the chuck table. Instead of uniform support across the entire die surface, protrusions are strategically placed only in sparse connection regions where the die is most susceptible to deformation. This localized support approach provides precise control over die shape during thinning while enabling overall package thickness reduction.
2Manufacturing precision
If uniform support is applied across the entire die surface during vacuum suction, then die deformation is prevented, but the complexity of the chuck table structure increases
Solution Approach 1:
The patent resolves this contradiction by applying local quality - instead of uniform support across the entire die surface, protrusions are strategically placed only in sparse connection regions. This localized approach provides necessary mechanical support to prevent deformation while keeping the chuck table structure simple and manageable.
Solution Approach 2:
The patent applies inversion by reversing the conventional approach: rather than using a flat chuck table surface that requires complex auxiliary support mechanisms, the solution creates protrusions that naturally provide the needed support. This inverted structure simplifies the overall system by integrating the support function directly into the chuck table geometry.
3Reliability
If the tape is made flexible to conform to the topography of conductive pillars, then the tape covers the pillars effectively, but recesses form under the tape causing deformation
Solution Approach 1:
The patent applies preliminary action by forming protrusions on the chuck table before tape application. These protrusions provide mechanical support that prevents the formation of recesses under the tape during the backside grinding process. By establishing this support structure in advance, the tape maintains its flatness while still conforming to conductive pillar topography.
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 implementation of supporters in the sparse region effectively reduces TTV, ensuring that conductive pillars are properly exposed and maintained within acceptable processing windows, enhancing the yield and reducing defects in the semiconductor package.
Implementation Method 1
fixating the semiconductor die by providing a suction force at the first surface
Data Source
AI summary
A semiconductor device includes a semiconductor die having a first surface and a second surface opposite to the first surface, a plurality of first real conductive pillars in a first region on the first surface, and a plurality of supporters in a second region adjacent to the first region. An area density of the plurality of supporters in the second region is in a range of from about 50% to about 100% to an area density of the plurality of first real conductive pillars in the first region. A method for manufacturing a semiconductor package including the semiconductor device is also disclosed in the present disclosure.