Image Sensor Package Via Structure for Low-Resistance Stacking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image sensor packages face challenges in ensuring reliable electrical connections, particularly in stacked structures where contact resistance and manufacturing process reliability are critical.
Innovation Solution
The image sensor package incorporates a via electrode structure that covers the inner sidewall and bottom surface of a via hole, connecting to multiple lower wiring patterns at different vertical levels, enhancing contact area and reducing resistance, while using a damascene process for forming wiring structures and metal-oxide hybrid bonding for substrate stacking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a via electrode structure covering inner sidewall and bottom surface is used, then electrical connection reliability is improved, but device complexity increases
Solution Approach 1:
The via electrode structure is formed in advance before substrate stacking, with the electrode material preliminarily deposited on the inner sidewall and bottom surface of the via hole. This preliminary formation ensures reliable electrical connection interfaces are ready before the bonding process, resolving the contradiction by preparing the connection structure beforehand rather than attempting to create it after stacking.
Solution Approach 2:
The via electrode structure transitions from a simple bottom-contact design to a three-dimensional structure covering both inner sidewall and bottom surface. This dimensional expansion increases the effective contact area and improves electrical connection reliability while the complexity is managed through systematic formation processes.
2Reliability
If contact area is increased by via electrode structure, then resistance is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The via electrode structure changes the contact geometry parameters by extending coverage from only bottom surface to include inner sidewall. This parameter change increases contact area and reduces resistance while the precision requirements are managed through controlled deposition processes that systematically form the electrode material on the expanded surface.
3Productivity
If stacked structure with multiple wiring layers is used, then integration density is improved, but contact resistance increases
Solution Approach 1:
The via electrode structure implements a nested configuration where the electrode material is positioned within the via hole, covering the inner sidewall and bottom surface. This nested arrangement creates multiple contact interfaces within the vertical stack, improving electrical connection reliability while maintaining the high integration density of the stacked structure.
Data Source
AI summary
An image sensor package includes a first substrate portion including a first substrate and an upper wiring structure, the upper wiring structure including a stacked structure including a plurality of upper wiring patterns and a plurality of upper wiring vias. The image sensor package includes a second substrate portion including a second substrate and a lower wiring structure, the second substrate defining a trench portion and a via hole. The lower wiring structure includes a stacked structure including a plurality of lower wiring patterns and a plurality of lower wiring vias. The lower wiring structure is in contact with the upper wiring structure, and the plurality of lower wiring patterns include a plurality of lower patterns at different vertical levels. The image sensor package includes a via electrode portion covering an inner sidewall and a bottom surface of the via hole.