Direct Write Pattern Alignment for 3D Stacked Dies
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Solution Overview
Problem
Current manufacturing methods for printed circuit boards face challenges in aligning connection points between dies in different layers of 3D stacked circuit packages, leading to inefficiencies and inaccuracies in the fan-out process due to stringent alignment requirements and random positional errors in die placement.
Innovation Solution
A method and apparatus that allow for more relaxed placement accuracy of dies by fitting pattern data to both distributed components in one layer and defined features in another layer within predetermined tolerances, using a direct write machine with a coordinate system for precise control, and a computer system to adjust circuit patterns for accurate alignment, distinguishing between 'sacred' and 'stretch' zones for alignment requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If stringent alignment requirements are imposed to ensure accurate connection between dies in different layers, then connection quality is improved, but manufacturing complexity and time increase
Solution Approach 1:
The patent divides the workpiece into multiple sub-areas, each associated with specific dies, and divides the circuit pattern into corresponding pattern portions. This segmentation allows independent alignment optimization for each die-sub-area pair, enabling parallel processing and reducing overall manufacturing time while maintaining high alignment accuracy for each individual connection.
Solution Approach 2:
The patent applies partial alignment actions by focusing computational and measurement resources only on the specific sub-areas and pattern portions that require alignment, rather than performing full-workpiece alignment. This partial action approach reduces the total alignment time and complexity while achieving the required connection accuracy.
2Manufacturing precision
If random positional errors in die placement are reduced to meet alignment tolerances, then alignment accuracy is improved, but placement time and cost increase
Solution Approach 1:
The patent implements a feedback mechanism where the actual measured positions of dies are used to adjust and transform the corresponding pattern data. By measuring the real positions and feeding this information back into the pattern transformation process, the system compensates for random placement errors without requiring extremely precise initial placement, thus reducing placement time and cost while maintaining alignment accuracy.
Solution Approach 2:
The patent transforms pattern parameters (position, orientation, scale) based on measured die positions to compensate for placement variations. This parameter transformation allows the pattern to adapt to actual die locations, reducing the stringency of placement accuracy requirements and enabling faster, less costly die placement processes.
3Manufacturing precision
If complex pattern transformation algorithms are used to align patterns to multiple dies simultaneously, then alignment accuracy is improved, but computational complexity and processing time increase
Solution Approach 1:
The patent segments the complex multi-die alignment problem into smaller sub-problems, each involving a die and its associated sub-area and pattern portion. This segmentation allows the use of simpler transformation algorithms for each subset while achieving accurate alignment across all dies collectively, reducing overall computational complexity.
Solution Approach 2:
The patent applies partial pattern transformations to specific sub-areas and pattern portions rather than transforming the entire pattern at once. This partial transformation approach reduces computational complexity and processing time while maintaining alignment accuracy for each local region, which collectively achieves global alignment accuracy.
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 approach enables accurate alignment of connection points between dies in different layers, reducing edge roughness and improving connection quality, thereby enhancing the cost efficiency and productivity of the fan-out process in 3D embedded die systems.
Implementation Method 1
exposing a photoresist or other photosensitive material
Implementation Method 2
annealing by optical heating, ablating
Implementation Method 3
ablating, creating any other change to the surface by an optical beam
Data Source
AI summary
A method for patterning a workpiece in a direct write machine in the manufacturing of a multilayer stack, wherein a first circuit pattern comprising patterns for connection points is transformed according to determined fitting tolerances to fit to connection points of a second circuit pattern and to circuit pattern(s) of specific features such as random placed dies, or group of dies, on or in the workpiece. The second layer may be a previously formed layer or a layer to be formed on the same workpiece or on a different workpiece for the stack. Pattern data associated with selected die is transformed into adjusted circuit pattern data using the transformation defined by the transformed positions such that the circuit pattern is fitted to the selected die(s).