Flexible Display Bump Alignment for Bonding Misalignment
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Solution Overview
Problem
Flexible display panels are prone to dimensional variations during the bonding process with chips, leading to misalignment and circuit interruptions due to their thinness and sensitivity to force, which affects production yield.
Innovation Solution
A display device with a flexible display panel and a chip bonded in a non-display area, where the bumps on the chip and panel are arranged such that their extension lines converge at specific points or angles relative to a reference line, allowing for adjustable alignment to compensate for dimensional variations, and a chip bonding method that uses alignment markings to determine and adjust for relative displacements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If flexible display panel is used to achieve thinness and flexibility, then the display device becomes thinner and more shock resistant, but dimensional variations occur during bonding process leading to misalignment
Solution Approach 1:
The patent applies preliminary action by pre-designing the bump geometry with specific orientation angles before the bonding process. The bumps are configured with extension lines that converge at predetermined points or form specific angles with the reference line, creating a built-in alignment mechanism that compensates for dimensional variations that occur during bonding. This pre-planned geometric configuration ensures proper alignment without requiring post-bonding adjustment.
Solution Approach 2:
The patent utilizes parameter changes by varying the extension line angles of the bumps relative to the reference line based on their position. Bumps in different zones (first zone with angle α, second zone with angle β) have different orientation parameters that correspond to the local dimensional variation characteristics. This spatially varying parameter configuration allows the bonding structure to accommodate dimensional changes while maintaining alignment.
2Ease of manufacture
If conventional bump alignment is used, then the bonding process is simple, but misalignment occurs due to dimensional variations affecting production yield
Solution Approach 1:
The patent applies local quality by configuring bumps with different extension line angles according to their specific spatial locations. The first zone bumps have angle α and the second zone bumps have angle β, where these angles are tailored to the local dimensional variation characteristics of each zone. This localized optimization allows the bonding process to remain relatively simple while significantly improving alignment accuracy and production yield across different regions of the flexible display panel.
3Ease of operation
If bumps are arranged parallel to reference line, then alignment is straightforward, but cannot compensate for dimensional variations in lateral zones
Solution Approach 1:
The patent applies asymmetry by intentionally designing the bump extension lines to converge at specific points or form different angles with the reference line depending on the zone, rather than making them all parallel. This asymmetric configuration creates a geometric relationship that compensates for the asymmetric dimensional variations that occur in lateral zones during bonding, thereby maintaining alignment reliability while preserving ease of operation through the systematic angle design.
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 arrangement ensures proper alignment and bonding between the chip and flexible display panel, even with minor dimensional variations, thereby improving the yield of the chip bonding process.
Implementation Method 1
Every two bumps in one-to-one correspondence are electrically connected through press bonding
Data Source
AI summary
A display device and chip bonding method thereof are provided. The display device includes a flexible display panel and a chip bonded to the non-display area of the flexible display panel with the extension directions of individual bumps satisfying, depending on the area in which the bumps are located, the following requirements: in each row of bumps, at least the individual bumps in lateral zones have their extension lines on the same side converging at a same point on the reference line, and the two bumps belong to a same bump group have their extension lines respectively forming an angle with respect to the reference line, the angles being equal to each other.