OLED Deposition Apparatus Glass Sag Prevention
Solution Overview
Problem
In the manufacturing of organic light-emitting display devices, larger glass substrates sag due to gravity, causing deformation of masks and alignment issues, which increases defect rates and complicates the deposition process.
Innovation Solution
A deposition apparatus that uses a support unit to apply pressure to the edge of the glass, causing it to protrude upward, and an electrostatic chuck to attract and align the glass without sagging, ensuring close contact with the mask and preventing mask deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If the glass substrate size is increased to meet display demands, then the display area and productivity are improved, but the glass sags due to gravity causing mask deformation and alignment issues
Solution Approach 1:
The patent applies an upward force through the deposition apparatus structure to counteract the gravitational sagging of the glass substrate. The glass is positioned on a support structure that provides mechanical counterbalancing, allowing large-area glass substrates to maintain planarity during the deposition process without causing mask deformation or alignment issues.
2Device complexity
If the glass substrate is allowed to sag naturally under gravity, then the manufacturing process is simpler, but mask deformation occurs and alignment precision deteriorates
Solution Approach 1:
The patent implements preliminary support and positioning of the glass substrate before the deposition process begins. The glass is pre-aligned and secured on a support structure that maintains its planar position throughout the process, preventing sag-induced mask deformation and eliminating the need for complex real-time alignment adjustments.
3Manufacturing precision
If mask deformation is prevented by supporting the glass, then alignment precision is improved, but the device structure becomes more complex
Solution Approach 1:
The patent introduces a support structure as an intermediary element between the glass substrate and the deposition mask. This mediator maintains the glass in a planar state, preventing direct contact and deformation of the mask, while providing stable alignment without requiring complex active control systems.
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 maintains the glass in a planar state, preventing mask deformation and simplifying alignment, thereby reducing defect rates and improving the uniformity of the deposition process.
Implementation Method 1
an attraction unit configured to attract the glass from a top side thereof
Implementation Method 2
a pressure unit is provided to apply pressure to the edge portion of the glass so that the center portion of the glass protrudes upward
Implementation Method 3
a crucible, in which an organic material is stored, is heated so that the vaporized organic material is deposited in the form of a thin film on a piece of glass
Data Source
AI summary
Disclosed is a deposition apparatus for an organic light-emitting diode, which is capable of preventing a large piece of glass from sagging due to gravity. The deposition apparatus allows the glass to be adhered to the lower surface of a planar electrostatic chuck from the center portion toward the edge portion thereof in the state in which it is upwardly convexly bent, thereby preventing deformation of a mask caused by the amount of sag of the glass. In addition, the deposition apparatus enables rapid alignment of the glass and the mask because the glass and the mask are adhered to each other via measurement of respective alignment marks provided thereon after the glass is located as close as possible to the mask without coming into contact with the mask.