Semiconductor Die Edge Bond Pads for Warping Reduction
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Solution Overview
Problem
As the number of semiconductor die in a stack increases, warping occurs at the distal ends due to unsupported edges, leading to mechanical instability and increased footprint in semiconductor memory devices.
Innovation Solution
Forming die bond pads partially in the kerf area between semiconductor die on a wafer, allowing for precise cutting during the stealth dicing before grinding process, which minimizes the offset between die and reduces warping by exposing bond pads at the edge of the diced die, thus enabling a smaller footprint and reduced warping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If die are stacked in an offset stepped configuration to enable wire bonding, then die bond pads are accessible for wire bonding, but distal ends of die overhang and are unsupported causing warping
Solution Approach 1:
The bond pads are repositioned from the traditional location on the die face to the edge of the die, utilizing the edge dimension for bonding access. This dimensional change allows bonds to be made at the die edge rather than requiring offset stacking for accessibility, thereby supporting the full die area and eliminating warping.
2Ease of operation
If die bond pads are positioned away from the die edge, then wire bonding is easier, but the offset between die increases leading to larger footprint
Solution Approach 1:
The bond pads are positioned asymmetrically at the edge of the die rather than centrally or offset from the edge. This asymmetric positioning at the extreme edge maximizes die-to-die overlap in stacked configurations, minimizing the horizontal footprint while maintaining bonding accessibility.
3Quantity of substance
If more die are stacked to increase capacity, then storage capacity increases, but warping at distal ends increases due to unsupported edges
Solution Approach 1:
By moving bond pad access to the die edge, the invention enables vertically stacked configurations where die can be directly stacked without horizontal offset. This allows increased die density and storage capacity while maintaining full die support and eliminating warping issues.
Data Source
AI summary
A semiconductor device is disclosed that is formed with die bond pads at an edge of the semiconductor die. The die bond pads may be formed partially in a kerf area between semiconductor die on a wafer. When the wafer is diced, the die bond pads are severed along their length, leaving a portion of the die bond pads exposed at an edge of the diced semiconductor die. Having die bond pads at the edge of the die minimizes the offset between die when stacked into a package.