Adaptive Patterning for Panelized Packaging Misalignment
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Solution Overview
Problem
Fan-out wafer level packaging processes often result in die displacement and rotation due to non-rigid attachment to temporary tape carriers and molding compound shrinkage, leading to misalignment and yield loss in panelized packaging.
Innovation Solution
An adaptive patterning technique using mask-less lithography measures the true position of each device unit and adjusts the build-up structure patterns, such as via and RDL patterns, to align with the measured positions, ensuring accurate alignment and reducing misalignment-related defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If die units are placed face down on temporary tape carrier and overmolded with epoxy molding compound, then panelized packaging can be efficiently manufactured, but die displacement and rotation occur due to non-rigid attachment and molding compound shrinkage, resulting in misalignment
Solution Approach 1:
The patent applies preliminary action by measuring the true position of each die unit immediately after molding while the panel is still on the carrier, before any singulation or repositioning occurs. This early measurement captures the actual positions of all die units, enabling subsequent alignment adjustments to be based on real data rather than estimates, thus resolving the misalignment issue while maintaining high productivity
Solution Approach 2:
The patent changes the parameter reference frame by establishing a panel-level coordinate system based on measured fiducial positions and actual die unit positions, rather than relying on the original design coordinate system. This parameter transformation allows the build-up structure patterns to be accurately aligned to the actual die positions, compensating for displacement and rotation that occurred during molding
2Reliability
If larger bond pad openings are used to accommodate misalignment, then alignment tolerance is improved, but the package area increases and efficiency decreases
Solution Approach 1:
The patent implements feedback by using the measured true positions of die units to dynamically adjust the alignment of build-up structure patterns. The measured position data feeds into the pattern generation process, creating a closed-loop system where actual conditions inform alignment decisions, thereby achieving high alignment tolerance without requiring larger bond pad openings
Solution Approach 2:
The patent applies local quality by generating individualized build-up structure patterns for each die unit based on its specific measured position and orientation. Rather than using a uniform pattern for all die units, each unit receives a customized pattern that precisely matches its actual location, maximizing alignment accuracy while minimizing the area required for bond pads
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 reduces yield loss by maintaining alignment with the package outline, allowing smaller bond pad openings, and eliminating the need for larger pads, thus enhancing the efficiency of panelized packaging processes.
Implementation Method 1
mask-less patterning technique utilizing laser ablation, direct write exposure, or other techniques
Implementation Method 2
mask-less patterning technique utilizing laser ablation, direct write exposure, or other techniques
Data Source
AI summary
An adaptive patterning method and system for fabricating panel based package structures is described. Misalignment for individual device units in a panel or reticulated wafer may be adjusted for by measuring the position of each individual device unit and forming a unit-specific pattern over each of the respective device units.