ITZO Connection Pad Composition to Prevent Display Pad Crystallization
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Solution Overview
Problem
Conventional display devices experience defects due to crystallization of indium tin oxide in connection pads during manufacturing, leading to pinhole formation and copper erosion, which affects the reliability and performance of the display.
Innovation Solution
The use of indium tin zinc oxide (ITZO) with a composition ratio of 20-35 at% indium, 2-20 at% zinc, 4-6 at% tin, and oxygen, in an amorphous state for the connection pads, prevents crystallization and copper erosion, thereby enhancing the structural integrity and reducing defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If indium tin oxide is used in connection pads, then electrical conductivity is improved, but crystallization occurs during manufacturing leading to pinhole formation and copper erosion
Solution Approach 1:
The patent modifies the chemical composition parameters of the oxide material by replacing some indium with zinc, creating indium zinc oxide with a specific composition range (In: 80-95 at%, Zn: 5-20 at%). This parameter change prevents crystallization while maintaining electrical conductivity, thereby resolving the contradiction between reliability and harmful crystallization effects.
Solution Approach 2:
The patent creates a composite oxide material combining indium and zinc elements in specific proportions. This composite material exhibits both high electrical conductivity and resistance to crystallization, simultaneously achieving the benefits of pure indium tin oxide while avoiding its crystallization defects.
2Manufacturing precision
If conventional indium tin oxide is used, then electrical conductivity is achieved, but pinhole formation and copper erosion occur reducing display quality
Solution Approach 1:
By changing the compositional parameters from conventional indium tin oxide to indium zinc oxide with specific ratios, the material resists crystallization during manufacturing processes. This prevents pinhole formation and copper erosion, thereby improving manufacturing precision and eliminating harmful defects.
3Reliability
If the connection pad material is changed to indium zinc oxide, then crystallization is prevented and defects are reduced, but material composition control complexity increases
Solution Approach 1:
The patent establishes specific composition ranges for indium zinc oxide (In: 80-95 at%, Zn: 5-20 at%) that provide a optimal balance between preventing crystallization and maintaining ease of manufacturing. These parameter specifications enable reliable defect-free production while keeping composition control manageable through clear numerical boundaries.
Data Source
AI summary
A display device includes a driving element disposed in a display area, an emission element disposed in the display area and electrically connected to the driving element, and a connection pad disposed in a pad area adjacent to the display area and electrically connected to the driving element. The connection pad includes a first pad conductive layer including a metal and a second pad conductive layer including indium tin zinc oxide (ITZO). The indium tin zinc oxide of the second pad conductive layer includes about 20 at % to about 35 at % of indium (In), about 2 at % to about 20 at % of zinc (Zn), about 4 at % to about 6 at % of tin (Sn), and a remainder of oxygen (O).