Photolithographic Alignment Features for Semiconductor Proximity Connectors
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Solution Overview
Problem
Current semiconductor technologies face challenges in aligning proximity connectors on adjacent semiconductor dies for effective capacitive communication, leading to misalignment issues that hinder communication performance and increase production costs due to the complexity of micro-sphere placement in existing mechanical mounting structures.
Innovation Solution
The use of photolithographically defined positive features such as hemispheres, bumps, ridges, and pyramids on semiconductor dies, which can mate with negative features to facilitate precise alignment in a wafer-scale process, allowing for simpler and lower-cost assembly of multi-chip modules (MCMs).
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If mechanical mounting structures with micro-spheres are used to align semiconductor dies, then alignment can be achieved, but the process complexity and cost increase due to the complexity of micro-sphere placement
Solution Approach 1:
The patent extracts and eliminates the micro-sphere placement step from the alignment process. By using photolithographically defined alignment marks that are directly patterned onto the semiconductor dies, the invention removes the need for separate micro-sphere placement operations, thereby reducing process complexity while maintaining alignment precision
Solution Approach 2:
The patent replaces the mechanical micro-sphere-based self-alignment system with a photolithographic alignment system. Instead of relying on physical micro-spheres to mechanically align dies, the invention uses photolithographically defined alignment marks that can be optically detected and used for precise positioning, substituting a mechanical approach with a photonic/fabrication-based approach
2Reliability
If tighter alignment tolerances are imposed on proximity connectors, then communication performance improves, but the difficulty of alignment increases
Solution Approach 1:
The patent performs alignment mark definition during the semiconductor fabrication process itself, before the dies are separated and packaged. By pre-defining alignment marks on the wafers using photolithography, the alignment infrastructure is prepared in advance, making subsequent alignment operations during assembly much easier and more precise
Solution Approach 2:
The patent creates photolithographic copies of alignment patterns directly on the semiconductor die surfaces. These alignment marks serve as precise reference copies that can be optically detected and used to guide the positioning of proximity connectors, enabling tight alignment tolerances through optical measurement rather than mechanical measurement
Data Source
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AI summary
Embodiments of a semiconductor die that includes proximity connectors proximate to a first surface of the semiconductor die are described. This semiconductor die is configured to communicate signals with another semiconductor die via proximity communication through one or more of the proximity connectors. Moreover, the semiconductor die includes a positive feature coupled to a second surface of the semiconductor die that facilitates mechanical alignment of the semiconductor die with the other semiconductor die. Note that a first region around the positive feature defines a first plane, and the positive feature protrudes above the first plane.