Chip-on-film bonding structure with stair-step layers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In display technologies, the bonding area in display substrates experiences uneven stress during the bonding process of chip-on-film (COF) structures, leading to potential damage of components like leads and reduced reliability of the display apparatus.
Innovation Solution
A COF structure is bonded to a base substrate using a bonding structure with a stair-step arrangement of pattern layers and insulating layers, where the COF structure contacts both parallel and angled surfaces of the bonding structure, ensuring uniform stress distribution and reducing the risk of component damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional bonding structure is used for COF bonding, then the bonding process is simple, but the stress distribution is uneven causing lead breakage and reduced reliability
Solution Approach 1:
The bonding structure is segmented into multiple pattern layers with different geometries (first pattern layer, second pattern layer, third pattern layer) that are stacked vertically. Each layer is designed with specific patterns that divide and distribute the bonding stress across multiple interfaces, preventing concentrated stress at any single location and thereby reducing lead breakage while maintaining reasonable structural complexity
Solution Approach 2:
The bonding structure transitions from a conventional two-dimensional planar bonding interface to a three-dimensional stacked configuration with multiple pattern layers. This vertical dimensionality addition allows stress to be distributed across multiple horizontal planes and vertical interfaces, creating a more robust bonding structure that handles stress more effectively without excessive complexity
2Strength
If the bonding area is increased to improve bonding strength, then the bonding strength increases, but the stress concentration and lead breakage risk increase
Solution Approach 1:
Each pattern layer is designed with locally optimized geometries where the first pattern layer, second pattern layer, and third pattern layer have different pattern configurations tailored to their specific positions in the stack. This local quality variation ensures that stress is evenly distributed across different regions and layers, preventing stress concentration while maintaining high bonding strength throughout the entire bonding area
Data Source
AI summary
The present disclosure provides a chip-on-film structure, a display apparatus and a methods for manufacturing the display apparatus. The display apparatus includes: a base substrate; a bonding structure disposed on the base substrate; and a chip-on-film COF structure, wherein the COF structure and a side of the bonding structure that is away from the base substrate are clamped with each other, and the COF structure is bonded to the side of the bonding structure that is away from the base substrate; wherein when the COF structure and the bonding structure are bonded, the COF structure contacts both a first surface and a second surface of the bonding structure at the side of the bonding structure that is away from the base substrate, wherein the first surface is parallel to the base substrate, and the second surface is at an angle with the first surface.