Asymmetric Bonding Pads for Flexible Substrate Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Flexible substrates in display devices, such as those made of organic materials like PI or PET, deform during bonding, leading to misalignment and potential short circuits between bonding pads due to expansion and contraction variations.
Innovation Solution
The substrate and chip on film designs feature non-parallel side edges and shape variations that allow bonding pads to adjust during deformation, ensuring secure bonding despite changes in substrate length, thereby preventing misalignment and short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If a flexible substrate is used, then the substrate can be made thin and lightweight, but the substrate deforms during bonding causing misalignment of bonding pads
Solution Approach 1:
The bonding pad is designed with an asymmetric trapezoidal shape where one longitudinal edge is longer than the other. This asymmetric geometry allows the bonding pad to accommodate substrate deformation during bonding while maintaining proper alignment, as the longer edge provides tolerance for the expected deformation direction.
Solution Approach 2:
The bonding pad's geometric parameters are specifically optimized with different lengths for its longitudinal edges. By changing the dimensional parameters of the bonding pad structure, the design compensates for substrate deformation and ensures reliable alignment between bonding pads on flexible substrates.
2Weight of moving object
If a flexible substrate is used, then the substrate can be made thin and lightweight, but misalignment and dislocation occur during bonding
Solution Approach 1:
The asymmetric trapezoidal bonding pad design provides built-in tolerance for substrate deformation. The unequal longitudinal edges are specifically configured to accommodate the expected deformation range, ensuring that bonding pads remain properly aligned and bonded even when the flexible substrate deforms during the bonding process.
Solution Approach 2:
By optimizing the geometric parameters of the bonding pad, particularly the lengths of its longitudinal edges, the design ensures reliable bonding despite substrate flexibility. The parameter optimization creates a tolerance zone that prevents misalignment and dislocation during bonding operations.
3Weight of moving object
If a flexible substrate is used, then the substrate can be made thin and lightweight, but short circuits may occur between adjacent bonding pads
Solution Approach 1:
The asymmetric trapezoidal bonding pad design, with one longer longitudinal edge, creates adequate spacing between adjacent bonding pads even when the flexible substrate deforms. This geometric configuration prevents the bonding pads from moving too close together, thereby eliminating the risk of short circuits between adjacent pads during bonding and operation.
Data Source
AI summary
The embodiments of the present invention provide a substrate, a chip on film and an electronic equipment. The substrate includes a plurality of first bonding pads arranged side by side along a first direction. Each first bonding pad has a first side edge and a second side edge arranged oppositely, which are arranged along the first direction. A third side edge and a fourth side edge of the first bonding pad are arranged oppositely and arranged along a second direction perpendicular to the first direction. The first side edge and second side edge of each first bonding pad are not parallel to each other.