Laser-Bonded Display Panel Layout for Higher Pixel Density
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional flat-panel displays face limitations in pixel density and fan-out due to the use of anisotropic conductive film for bonding drivers, which requires pressure and restricts area allocation for pixels, making repair and re-bonding difficult and limiting the achievement of slim borders.
Innovation Solution
The display panel employs integrated circuits bonded to a substrate via laser-interconnected IC pads and substrate pads, eliminating the need for anisotropic conductive film and allowing for single-sided IC pad placement, thereby increasing pixel density and facilitating easier repair and re-bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If anisotropic conductive film (ACF) is used to bond drivers on the substrate, then reliable bonding is achieved, but driver pads must be disposed on at least two opposite sides requiring pressure equilibrium, which reduces area allocation for pixels and limits pixel density
Solution Approach 1:
The patent extracts and eliminates the ACF bonding process entirely, replacing it with direct laser bonding of IC pads to substrate pads. This removes the requirement for dual-sided pad disposal and pressure equilibrium, freeing up pixel area while maintaining reliable bonding through direct laser-induced bonding.
Solution Approach 2:
The patent replaces the mechanical pressure-based ACF bonding system with a thermal laser bonding system. Instead of applying mechanical pressure through ACF to bond drivers, the invention uses laser beams to directly bond IC pads to substrate pads through localized heating and material fusion, eliminating the need for mechanical pressure equilibrium.
2Area of stationary object
If drivers are disposed between adjacent rows of pixels or on border to save area, then area allocation is optimized, but pixel density and fan-out of driver pads are substantially decreased and repair or re-bonding becomes difficult
Solution Approach 1:
The patent segments the driver functionality into separate, independently bondable IC modules that can be individually replaced. Each IC with its pads can be bonded and removed independently, enabling easy repair and re-bonding without affecting other pixels or drivers, while maintaining flexible area allocation.
Solution Approach 2:
The patent changes the bonding method from permanent mechanical ACF bonding to laser bonding, which creates bonds that can be selectively broken and reformed. This parameter change in bonding methodology enables easy repair and re-bonding while allowing drivers to be positioned in area-optimized locations without compromising future maintainability.
3Reliability
If ACF hot pressing is used for bonding, then bonding is achieved, but short-circuits may occur between adjacent IC pads due to pressure and heat distribution
Solution Approach 1:
The patent replaces the mechanical ACF hot pressing system with a laser bonding system that uses focused thermal energy instead of distributed mechanical pressure. The laser provides localized heating precisely at the bonding interface, achieving reliable bonding without the widespread pressure and heat distribution that causes adjacent pad short-circuits in ACF bonding.
Solution Approach 2:
The patent applies local quality by concentrating the bonding energy precisely where needed through laser focus. The laser beam delivers heat only to the specific IC pad and substrate pad contact interface, creating localized bonds without affecting adjacent pads. This localized energy application prevents short-circuits while achieving reliable bonding.
4Reliability
If dual side driver pad disposal is required for pressure equilibrium in ACF bonding, then bonding reliability is maintained, but fan-out of driver pads is substantially limited
Solution Approach 1:
The patent extracts and eliminates the ACF bonding process that requires dual-sided pad disposal for pressure equilibrium. By removing this constraint, the invention enables single-sided or flexible pad placement configurations that significantly increase driver pad fan-out and adaptability without compromising bonding reliability through laser bonding.
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 approach increases pixel density, reduces IC size, and simplifies the repair process while avoiding short-circuits associated with traditional ACF hot pressing, allowing for finer pitch IC pads and reduced IC size, thus enhancing display performance and maintenance.
Implementation Method 1
The ICs are bonded on the substrate via the IC pads and the substrate pads, which are interconnected by laser as a heat source.
Implementation Method 2
the IC pads and the substrate pads, which are interconnected by laser as a heat source
Data Source
AI summary
A display panel includes a substrate composed of a plurality of pixels; and a plurality of integrated circuits (ICs) disposed on a top surface of the substrate, each IC including a plurality of IC pads and the substrate including a plurality of substrate pads corresponding to the IC pads and disposed on the top surface of the substrate. In one embodiment, the ICs are bonded on the substrate via the IC pads and the substrate pads, which are interconnected by laser as a heat source. In another embodiment, each IC is disposed above to cover up at least one pixel.