Chuck Plate Cooling for OLED Shadow Mask Alignment
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Solution Overview
Problem
The precision of organic light emitting diode (OLED) pattern positioning is compromised due to thermal deformation caused by radiant heat from the deposition source and conductive heat from the shadow mask, leading to discoloration defects in OLEDs, as existing cooling methods only address the shadow mask frame and not the glass substrate effectively.
Innovation Solution
A shadow mask frame assembly with a heat-radiating and cooling function, incorporating a cooling plate with a refrigerant circulating duct in the chuck plate, which intercepts radiant heat and cools the glass substrate to minimize thermal expansion and alignment errors between the glass substrate and the shadow mask.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the shadow mask frame is cooled to prevent thermal expansion, then the pattern positioning precision is improved, but the glass substrate still experiences thermal deformation due to radiant heat and conductive heat from the shadow mask
Solution Approach 1:
The cooling system is divided into two independent parts: a shadow mask frame cooling system and a glass substrate cooling system. The glass substrate cooling system includes a chuck plate with refrigerant circulating ducts that are independently controlled, allowing separate optimization of cooling for each component without interfering with the shadow mask frame cooling.
Solution Approach 2:
The chuck plate serves as an intermediary cooling medium between the glass substrate and the shadow mask frame. It has refrigerant circulating ducts embedded in its structure, allowing it to cool the glass substrate through thermal conduction while maintaining mechanical support and alignment functions.
2Manufacturing precision
If the glass substrate is cooled to prevent thermal deformation, then the alignment precision is improved, but the device complexity increases due to additional cooling structures
Solution Approach 1:
The chuck plate is designed to perform multiple functions: mechanical support for the glass substrate, alignment with the shadow mask frame, and thermal cooling through integrated refrigerant circulating ducts. This multi-functionality reduces the need for separate cooling components and simplifies the overall device structure.
Solution Approach 2:
The refrigerant circulating ducts are embedded within the chuck plate structure itself, creating a nested configuration where the cooling system is integrated into the mechanical support structure. This nesting approach minimizes additional space requirements and structural complexity.
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
The solution effectively prevents thermal deformation of both the shadow mask and glass substrate, enhancing the precision of OLED pattern positioning by maintaining a stable temperature and reducing thermal expansion, thereby minimizing discoloration defects.
Implementation Method 1
conductive heat caused by contact with a shadow mask
Implementation Method 2
a refrigerant is circulated in the chuck plate
Implementation Method 3
radiant heat from a deposition source
Data Source
AI summary
The invention provides a chuck plate assembly that includes a shadow mask formed with a predetermined pattern; a shadow mask frame holding the shadow mask and having heat-radiating and cooling functions; a substrate aligned with the shadow mask and onto which deposition materials from a deposition source are deposited; and a chuck plate, attaching the substrate to the shadow mask, that includes a refrigerant circulating duct. The temperature of the substrate is optimized in consideration of the temperature of the shadow mask so that an alignment error due to thermal deformation is minimized. That is, the temperature of the shadow mask itself is prevented from rising, and thereby prevents deformation of the shadow mask due to thermal expansion, which improves the precision of a substrate pattern position.