Through-Substrate Display Module Layout for Larger Active Area
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current display module packaging technologies, such as COG and COF, face challenges in reducing the form factor and improving system performance due to the need for extensive space allocation for driver ICs and FPCs, which limits the display area and increases thickness, and are not compatible with OLED and LCD technologies that require specific protection from air and moisture.
Innovation Solution
The proposed solution involves a display module with interconnects, such as through vias, that extend through the display substrate from the front to the back surface, allowing driver circuits to be located on the back surface, eliminating the need for a FPC and PCB, and enabling the use of flexible display substrates that can be integrated into wearable devices and TVs, with micro LEDs and chips electrically connected through these interconnects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If driver ICs and FPCs are mounted on the front surface of the display substrate, then electrical connection is achieved, but the display area is reduced and the form factor is increased
Solution Approach 1:
The patent applies dimensionality change by moving driver circuits from the front surface (2D plane) to the back surface of the display substrate, utilizing the third dimension (depth/thickness) to resolve the conflict between display area and electrical connection requirements. This allows the front surface to be fully dedicated to display while driver circuits are positioned on the back surface, connected through vertical interconnects.
2Reliability
If a rigid glass cover is used to protect OLED from air and moisture, then reliability is improved, but weight and thickness are increased
Solution Approach 1:
The patent replaces rigid glass encapsulation with flexible thin-film encapsulation layers deposited directly on the OLED structure. These thin films provide the necessary barrier against air and moisture while being significantly lighter and thinner than traditional glass covers, enabling flexible display applications and reducing overall device weight.
3Length of stationary object
If through vias are used to extend interconnects through the display substrate, then driver circuits can be placed on the back surface reducing form factor, but manufacturing complexity increases
Solution Approach 1:
The patent incorporates the formation of through vias and interconnect structures as preliminary steps during the substrate fabrication process itself, rather than as post-processing additions. This integration of via formation into the manufacturing flow minimizes additional complexity and enables the back-surface mounting approach to achieve reduced form factor benefits.
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 configuration reduces the x-y and z form factors, allowing for a larger display area and thinner devices, while being compatible with OLED and LCD technologies, and enables flexible display panels that can be curved or rolled, enhancing user interaction and design flexibility.
Implementation Method 1
An array of light emitting diodes (LEDs) are in the display area and electrically connected with the plurality of interconnects
Data Source
AI summary
A display module and system applications including a display module are described. The display module may include a display substrate including a front surface, a back surface, and a display area on the front surface. A plurality of interconnects extend through the display substrate from the front surface to the back surface. An array of light emitting diodes (LEDs) are in the display area and electrically connected with the plurality of interconnects, and one or more driver circuits are on the back surface of the display substrate. Exemplary system applications include wearable, rollable, and foldable displays.