Foldable Digitizer Adhesive Stack for Reliable Sensing

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Solution Overview

Problem

Existing electronic apparatuses face challenges in reliability and manufacturing methods that do not adequately enhance visibility and folding properties.

Innovation Solution

The electronic apparatus incorporates a digitizer with first and second sensing coils covered by multi-curing adhesive layers, a shielding layer, and additional adhesive and cushion layers, along with a light blocking layer, to improve reliability and folding capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multi-curing adhesive layers are used to cover sensing coils, then reliability is improved, but device complexity increases

Engineering Contradiction:

Improvesensing reliabilityVSAvoidadhesive layer structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The adhesive system is divided into multiple curing stages with different adhesive layers (first adhesive layer, second adhesive layer, third adhesive layer) that cure at different times and conditions. This segmentation allows each layer to perform its specific function optimally while contributing to overall reliability of the sensing coil assembly.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first and second adhesive layers are applied and partially cured before final assembly, allowing the sensing coils to be positioned and secured in advance. This preliminary action ensures proper alignment and initial bonding strength before the final curing stage completes the assembly.

Inventive Principle:

Principle #10Preliminary action

2Strength

If additional protective layers (shielding, cushion, light blocking) are added, then durability and folding properties improve, but device complexity increases

Engineering Contradiction:

Improvefolding durabilityVSAvoidlayer structure

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The patent employs a composite structure combining multiple functional layers: shielding layer (metal or conductive material) for electromagnetic protection, cushion layer (elastic or foam material) for mechanical shock absorption, and light blocking layer (pigment-containing material) for optical control. Each layer is made from composite materials designed to provide specific protective functions while working together to enhance overall durability and folding properties.

Inventive Principle:

Principle #40Composite materials

3Measurement precision

If adhesive layers entirely overlap sensing coils, then sensing precision is improved, but manufacturing precision requirements increase

Engineering Contradiction:

Improveinput sensing precisionVSAvoidadhesive layer alignment

Core Design Contradiction:

Measurement precisionVSManufacturing precision

Solution Approach 1:

The adhesive layers are designed with varying overlap extents at different locations. The first adhesive layer entirely overlaps the first sensing coil in the first region, while the second adhesive layer entirely overlaps the second sensing coil in the second region. This local quality approach ensures complete coverage where needed for sensing precision while allowing manufacturing flexibility through the multi-curing process that tolerates alignment variations.

Inventive Principle:

Principle #3Local quality

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

The solution enhances the apparatus's reliability and visibility by ensuring precise sensing and durable folding, while maintaining structural integrity and reducing external impacts.

Implementation Method 1

a first adhesive layer disposed on the first sensing coil, and a second adhesive layer disposed on the second sensing coil

Methodology Applied

Scientific EffectAdhesion: Adhesive

Implementation Method 2

a shielding layer disposed below the second adhesive layer. The shielding layer may include a metal

Methodology Applied

Scientific EffectElectromagnetic shielding: Faraday Cage

Implementation Method 3

a magnetic sheet disposed on the shielding layer. The magnetic sheet may include magnetic metal powder (MMP)

Methodology Applied

Scientific EffectMagnetic absorption: Ferromagnetic Powder

Implementation Method 4

a light blocking layer disposed on the first adhesive layer. The light blocking layer may have a transmittance of about 50% or less

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Data Source

PatentUS12547289B2Electronic apparatus and manufacturing method of the same

Publication Date: 2026.02.10 SAMSUNG DISPLAY CO LTD

AI summary

An electronic apparatus includes a window, a display panel disposed below the window, and a digitizer disposed below the display panel. The digitizer includes a base layer having a first surface and a second surface opposing the first surface, a first sensing coil disposed on the first surface of the base layer, a second sensing coil disposed on the second surface of the base layer, a first adhesive layer disposed on the first sensing coil, and a second adhesive layer disposed on the second sensing coil. The first adhesive layer and the second adhesive layer are multi-curing adhesive layers.