Adhesive Pressure Bonding for Display Substrate Connection Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing display devices, such as organic light-emitting display devices, face issues with bonding reliability due to continuous stress from bent flexible printed circuit boards, leading to potential damage and reduced connection reliability.
Innovation Solution
The implementation of an adhesive pressure bonding method using an encapsulation substrate with flexible pads and conductive connectors between the display and circuit substrates, which extends beyond the display area and includes conductive patterns and insulating resin for secure electrical connections, eliminating the need for bending the circuit substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the FPCB is bent toward and attached to the rear surface of the substrate to reduce area and prevent interference, then the display device area is reduced and interference is prevented, but continuous stress is applied to the pad bonding part causing damage and reduced bonding reliability
Solution Approach 1:
The patent extracts the bending operation from the FPCB assembly process. Instead of bending the FPCB to fit, the FPCB is kept flat and the substrate is designed with an extended rear surface that accommodates the FPCB in its natural state, eliminating the stress-causing bending action while achieving compact integration
Solution Approach 2:
Instead of bending the FPCB to match the substrate contour, the patent inverts the approach by extending the substrate rear surface to match the FPCB's flat configuration. This reverses the traditional assembly logic and eliminates the harmful bending stress on bonding pads
2Reliability
If the FPCB is bent to connect pads, then electrical connection is achieved, but cracks and connection malfunctions occur due to continuous stress
Solution Approach 1:
The patent converts the potential harm of FPCB bending into a benefit by designing the substrate rear surface extension to accommodate the FPCB in its preferred flat state. The extended substrate area, which could be seen as wasted space, becomes a beneficial feature that enables stress-free FPCB mounting and improves connection reliability
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 enhances bonding reliability, prevents cracks and connection malfunctions, and reduces assembly time by eliminating the need for substrate bending, thereby protecting the display driver IC and maintaining connection integrity.
Implementation Method 1
a conductor for electrically connecting the plurality of first patterns and the plurality of second patterns to each other
Implementation Method 2
at least one connector is formed on surfaces of the display unit and the encapsulation substrate which face each other, the at least one connector configured to provide a connection path between the display unit and the circuit board by being adhesively pressed
Data Source
AI summary
A display device includes: a display substrate in which a display for displaying an image is formed; an encapsulation substrate, which is assembled on the display substrate and has a first surface facing the display substrate and a second surface opposite to the first surface; and a circuit substrate for transferring an electrical signal to the display, where a plurality of pads, which are electrically connected to the display and connected to the circuit substrate, are formed on the first surface of the encapsulation substrate, and at least one connector is formed on surfaces of the display and the encapsulation substrate which face each other, the connector configured to provide a connection path between the display and the circuit board by being adhesively pressed in a vertical direction.