Directly Bonded Semiconductor Pads for Thermal Mismatch Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor packages face challenges in improving reliability, durability, and electrical characteristics due to conventional bonding methods that do not effectively address thermal expansion coefficient mismatches between semiconductor chips.
Innovation Solution
The semiconductor package design includes direct bonding of semiconductor chips using interconnection patterns with larger widths than bonding pads, and penetration vias with smaller widths, allowing for robust connections through chemical bonding and simplified fabrication processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional bonding methods are used to connect semiconductor chips, then the fabrication process is simpler, but the reliability and durability are reduced due to thermal expansion coefficient mismatches
Solution Approach 1:
The patent introduces an intermediate layer structure consisting of a first interconnection layer, a second interconnection layer, and a bonding pad layer that acts as a mediator between the first and second semiconductor chips. This intermediate structure accommodates thermal expansion coefficient mismatches by providing a compliant interface, thereby improving reliability while managing the complexity through a systematic multi-layer approach
Solution Approach 2:
The patent employs parameter changes by varying the material composition, thickness, and structural configuration of the interconnection layers and bonding pads. By adjusting these parameters, the design optimizes thermal stress distribution and electrical performance, resolving the contradiction between improved reliability through advanced bonding and controlled fabrication complexity
2Reliability
If direct bonding of bonding pads is implemented, then electrical characteristics are improved, but the manufacturing precision requirements increase due to width variations in interconnection patterns and penetration vias
Solution Approach 1:
The patent deliberately introduces asymmetry in the design by making the width of the second interconnection pattern larger than the width of the second bonding pad, and the width of the first penetration via smaller than the width of the first bonding pad. This asymmetric design provides manufacturing tolerance buffers that reduce alignment precision requirements while maintaining excellent electrical characteristics through the direct bonding interface
Solution Approach 2:
The patent implements beforehand cushioning by designing the asymmetric width relationships between interconnection patterns, penetration vias, and bonding pads in advance. This pre-built tolerance cushioning accommodates potential alignment variations during manufacturing, ensuring reliable electrical connections without requiring extremely high precision bonding alignment
3Strength
If penetration vias with smaller widths than bonding pads are used, then the connection robustness is improved, but the device complexity increases due to multiple width variations in interconnection structures
Solution Approach 1:
The patent applies local quality by optimizing the width of each interconnection element according to its specific function: penetration vias have smaller widths for robust mechanical anchoring, bonding pads have larger widths for reliable electrical bonding, and interconnection patterns have varied widths for current distribution and stress management. This localized optimization enhances connection robustness while the systematic design keeps overall device complexity manageable
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 design enhances the reliability and durability of semiconductor packages by ensuring strong, robust connections and reducing fabrication complexity, while maintaining electrical integrity.
Implementation Method 1
The second bonding pad may be directly bonded to the first bonding pad
Data Source
AI summary
A semiconductor package may include a first semiconductor chip and a second semiconductor chip on a top surface thereof. The first semiconductor chip may include a first bonding pad on a top surface of a first semiconductor substrate and a first penetration via on a bottom surface of the first bonding pad and penetrating the first semiconductor substrate. The second semiconductor chip may include a second interconnection pattern on a bottom surface of a second semiconductor substrate and a second bonding pad on a bottom surface of the second interconnection pattern and coupled to the second interconnection pattern. The second bonding pad may be directly bonded to the first bonding pad. A width of the first penetration via may be smaller than that of the first bonding pad, and a width of the second interconnection pattern may be larger than that of the second bonding pad.