Optical Sensing Device Curved Slit Design for Film Warpage

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Solution Overview

Problem

The production yield of optical sensing devices is compromised due to film warpage and subsequent air or gas rushing into the film cutting design, leading to sealant puncture or wire breakage during the manufacturing process.

Innovation Solution

The optical sensing device incorporates a substrate with a sensing region and a non-sensing region, featuring planarization layers with slits and trenches that prevent air or gas from rushing in, using curved or zigzag patterns to resist pressure changes and improve structural integrity, thereby enhancing production yield.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If film cutting design is applied to release stress in organic thick film, then warpage issue is solved, but air or gas rushes into the film cutting area during vacuum relief, causing sealant puncture or wire breakage

Engineering Contradiction:

Improvefilm flatnessVSAvoidproduction yield

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

The patent applies curved or zigzag patterns to the slits in the planarization layer instead of straight linear cuts. This curvature design increases the path length and resistance to air/gas flow during vacuum relief, preventing rapid rushes that cause sealant puncture or wire breakage, while still allowing stress release to maintain film flatness

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent divides the planarization layer into multiple separate slits rather than using a continuous film cutting design. This segmentation creates multiple smaller stress release zones that collectively maintain film flatness while reducing the overall vulnerability to air/gas rushes, thereby improving production yield

Inventive Principle:

Principle #1Segmentation

2Manufacturing precision

If organic thick film is stacked to ensure sufficient thickness for microlens focusing collimation, then fingerprint image clarity is improved, but temperature changes during manufacturing cause warpage

Engineering Contradiction:

Improvefingerprint image clarityVSAvoidfilm flatness

Core Design Contradiction:

Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The patent introduces slits that divide the organic thick film into multiple segments. This segmentation allows the film to expand and contract independently in different regions during temperature changes, releasing thermal stress and preventing warpage while maintaining sufficient overall thickness for microlens focusing collimation and fingerprint image clarity

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS11639870B2Optical sensing device

Publication Date: 2023.05.02 AU OPTRONICS CORP

AI summary

An optical sensing device includes a substrate, a sensing element layer, a first planarization layer, and a second planarization layer. The sensing element layer is located on the substrate and includes a plurality of sensing elements. The first planarization layer is located on the sensing element layer and has a first slit. The second planarization layer is located on the first planarization layer and has a second slit. An orthogonal projection of the first slit extending in a direction and located on the substrate is not overlapped with an orthogonal projection of the second slit extending in the same direction and located on the substrate, and the orthogonal projection of the second slit on the substrate has a curved pattern.