Film Frame Carrier Pre-Alignment Using Overview Image Scanning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for pre-aligning film frame carriers (FFCs) during semiconductor fabrication are inaccurate, particularly for reconstituted wafers, leading to alignment errors and reduced throughput due to mechanical limitations and variability in frame notch shapes, and cannot handle rotated FFCs, limiting system arrangements and use cases.
Innovation Solution
A system comprising a film frame carrier (FFC) rotator, end effector, scanner, and processor that generates an overview image to determine and correct alignment between the FFC and end effector, allowing for precise rotational and translational adjustments, and identifies missing dies, reducing the need for separate inspection processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If mechanical alignment features (pins and notches) are used for FFC pre-alignment, then the alignment process is simple and fast, but the alignment accuracy is low and cannot handle rotated FFCs
Solution Approach 1:
The patent replaces the mechanical alignment system (pins and notches) with an optical/image-based alignment system. A scanner captures an overview image of the FFC, and image processing algorithms determine the FFC's position and orientation. This substitution enables high alignment accuracy (better than 100 μm) while accommodating rotated FFCs, eliminating the limitations of mechanical features.
Solution Approach 2:
The patent creates an optical copy (overview image) of the FFC instead of relying on direct mechanical contact. This image copy contains all necessary alignment information and can be processed computationally to determine precise FFC position and orientation, enabling accurate alignment without physical alignment features on the FFC.
2Reliability
If a separate pre-scan inspection process is added to detect misaligned or missing dies, then detection capability is improved, but inspection time per wafer increases and throughput decreases
Solution Approach 1:
The patent merges the alignment determination function with the overview image scanning process. The same scanner that captures the overview image for alignment purposes also enables detection of misaligned or missing dies through image processing. This consolidation eliminates the need for a separate pre-scan inspection process, maintaining high reliability while preserving throughput.
Solution Approach 2:
The overview image scanning system serves multiple functions simultaneously: it determines FFC alignment, detects misaligned dies, identifies missing dies, and provides positional information. This multi-functionality eliminates the need for dedicated separate inspection processes, improving productivity while maintaining reliability.
3Adaptability or versatility
If mechanical alignment features are used on FFC frames, then alignment can be achieved, but the frame design becomes more complex and not all FFC types (e.g., recon wafers) can be accommodated
Solution Approach 1:
The patent eliminates the need for mechanical alignment features (notches) on FFC frames by using an optical/image-based alignment system. The scanner captures the overview image and processing algorithms determine FFC position and orientation without requiring any special mechanical features on the frame. This approach accommodates all FFC types including recon wafers while simplifying frame design.
Data Source
AI summary
The system includes a film frame carrier (FFC) configured to support a workpiece, and the FFC is removably disposed on an FFC rotator. The system further includes an end effector configured to engage the FFC to remove the FFC from the FFC rotator and a scanner disposed in a movement path of the end effector. The scanner is configured to generate an overview image of the end effector engaged with the FFC as the end effector moves away from the FFC rotator. The system further includes a processor configured to receive the overview image from the scanner, determine an alignment between the FFC and the end effector according to the overview image, and control a movement of the end effector according to the alignment between the FFC and the end effector.