Evaporation Alignment Device for Opaque Silicon Micro OLED Substrates
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Solution Overview
Problem
Conventional glass-based alignment schemes are inadequate for silicon-based micro OLED displays due to the opacity of silicon wafers, requiring a more precise and effective alignment method during evaporation processes.
Innovation Solution
An alignment device comprising a first module outside the evaporation chamber for determining relative position information and a second module inside the chamber for adjusting the substrate and mask positions, utilizing a light propagation structure with reflectors to accurately align the substrate and mask, ensuring precise overlap of alignment marks with a hollowed area on the mask.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional glass-based alignment schemes are used, then the alignment process is simple, but the alignment precision is insufficient for silicon-based OLED substrates
Solution Approach 1:
The alignment system is divided into two independent modules: a first alignment module located outside the evaporation chamber for determining relative position information, and a second alignment module located inside the chamber for adjusting substrate and mask positions. This segmentation allows each module to be optimized independently, achieving high precision without excessive overall complexity.
Solution Approach 2:
A light propagation structure with reflectors is introduced as an intermediary to transmit light reflected by alignment marks on the opaque silicon substrate to the image detector. This mediator enables optical detection through the evaporation chamber environment, solving the problem of aligning opaque substrates without directly complicating the alignment mechanism.
2Object-affected harmful factors
If the substrate is placed face down in the evaporation chamber, then foreign particles are prevented from falling on the substrate, but alignment mark detection becomes difficult
Solution Approach 1:
The light propagation structure uses reflectors positioned at specific angles (e.g., 45 degrees) to redirect light paths in three-dimensional space. Light reflects off the alignment mark on the face-down substrate, travels through the hollowed area, bounces off reflectors, and reaches the image detector from a different spatial dimension, enabling detection without changing the substrate's face-down orientation.
Solution Approach 2:
The light propagation structure with reflectors acts as an intermediary optical path that bridges the gap between the face-down substrate and the image detector. It transmits alignment mark information through the evaporation chamber environment without requiring the substrate to be repositioned, thus preventing contamination while enabling detection.
3Reliability
If the substrate is opaque, then it provides good electrical properties, but conventional optical alignment methods cannot be applied
Solution Approach 1:
The light propagation structure with reflectors serves as an intermediary that extracts and transmits optical information from the opaque substrate. By reflecting light off the alignment marks and guiding it through the hollowed area to the image detector, the system makes invisible features visible without requiring the substrate to become transparent, thus preserving electrical properties while enabling optical detection.
Solution Approach 2:
The system utilizes optical reflection properties of alignment marks on the opaque substrate. By illuminating the alignment marks and detecting the reflected light through the light propagation structure, the system creates detectable optical contrast on the opaque surface, enabling alignment mark detection without changing the substrate's fundamental opaque nature and electrical properties.
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 solution enables precise alignment of silicon-based OLED display substrates during evaporation, reducing alignment errors to within 50 um and preventing foreign particles from affecting the alignment process, thus ensuring high pixel density and quality in micro OLED displays.
Implementation Method 1
a light propagation structure, located on a side of the mask for evaporation that is facing away from the substrate to be evaporated, the light propagation structure directly facing the hollowed area, and configured to transmit light reflected by the first alignment mark to the image detector
Data Source
AI summary
An alignment method, an alignment device and evaporation equipment are provided. The alignment device includes: a first alignment module, located outside an evaporation chamber and configured to determine relative position information between a substrate to be evaporated and a mask for evaporation; a second alignment module, located in the evaporation chamber and configured to adjust a position of the substrate to be evaporated and/or the mask for evaporation according to the relative position information until an orthographic projection of a first alignment mark of the substrate to be evaporated on the mask for evaporation at least partially overlaps a hollowed area of the mask for evaporation, obtain position information of the first alignment mark through the hollowed area, and adjust a position of the substrate to be evaporated and/or the mask for evaporation according to the position information.