Microchip Self-Assembly Using Capillary Self-Alignment for 3D ICs
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Solution Overview
Problem
Current 3D microelectronic component integration methods face challenges in achieving high precision and speed in assembly, particularly with the 'chip-to-plate' approach, which is not industrially viable due to the need for precise alignment and the complexity of using 'pick-and-place' machines, and the difficulty in integrating protuberances on processed substrates.
Innovation Solution
A self-assembly process that dissociates self-alignment and self-assembly steps, using a self-aligning substrate with hydrophobic protuberances and hydrophilic chip faces to achieve precise alignment by capillary effect, followed by direct bonding on a self-assembly substrate, allowing for high bonding energy between chips and the substrate without requiring protuberances on the final substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If pick-and-place machines are used to achieve precise alignment, then manufacturing precision is improved, but productivity deteriorates
Solution Approach 1:
The patent implements self-alignment through capillary forces where liquid bridges automatically form between chips and substrate, eliminating the need for complex robotic positioning systems. The physical phenomenon of capillary action inherently provides the alignment function without requiring high-precision mechanical control, thus maintaining both precision and throughput
Solution Approach 2:
The patent replaces mechanical alignment mechanisms (robotic pick-and-place systems) with a physical-chemical mechanism (capillary forces). By using liquid bridges that form through surface tension and capillary action, the system achieves precise positioning without relying on mechanical precision, thereby improving productivity while maintaining alignment quality
2Manufacturing precision
If protuberances are integrated on processed substrates to enable self-alignment, then manufacturing precision is improved, but device complexity deteriorates
Solution Approach 1:
The patent extracts the alignment function from the substrate structure itself and transfers it to the liquid bridge medium. Instead of incorporating complex protuberances into the processed substrate, the invention uses liquid capillary forces to provide the alignment mechanism, thereby simplifying the substrate structure while maintaining precise self-alignment capability
Solution Approach 2:
The patent introduces liquid bridges as an intermediary element between chips and substrate. These liquid bridges serve dual functions: they provide capillary forces for precise self-alignment and also facilitate subsequent bonding. This intermediary approach eliminates the need for complex substrate protuberances while achieving the desired alignment precision
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 method achieves micrometric self-alignment for 90% of chips with high efficiency and allows for heterogeneous hybridization, overcoming the limitations of existing methods by enabling precise alignment and assembly without the need for complex protuberance integration, thus making industrial-scale 3D IC manufacturing more feasible.
Implementation Method 1
the upper face and the flanks being hydrophobic, Obtaining, by capillary effect, the self-alignment of each chip, by its first face, on a single protrusion
Implementation Method 2
Obtaining the assembly of the plurality of chips on the self-assembly substrate, typically according to a 'plate to plate' type approach, by direct bonding to the self-assembly substrate of the second hydrophilic face of each chip
Data Source
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AI summary
The invention relates to the field of three-dimensional integration of microelectronic components and, more particularly, to a self-assembly method (100) for microelectronic components, comprising: - providing (101) a so-called self-alignment substrate comprising a plurality of protrusions each having a thickness greater than 1 µm and an upper face and sides, the upper face and sides being hydrophobic, - providing (102) a plurality of chips, each chip having a first face and a second hydrophilic face - providing (103) a so called self-assembly substrate, - obtaining (104), by capillary effect, the self alignment of each chip by its first face on a protrusion of the self-alignment substrate, then - obtaining (105) the assembly of the plurality of chips by their second hydrophilic face on the self-assembly substrate by direct glueing. The invention can be used for the industrial production of 3-D integrated circuits.