Planar Coil Antenna Module With Bulged Adhesive Layers for Flatness

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Solution Overview

Problem

Existing antenna modules suffer from irregularities in the adhesive layer, leading to loss of flatness when attached to objects, which can result in progressive short-circuit failures.

Innovation Solution

The antenna module features a coil pattern sandwiched between a first and second adhesive layer, with the adhesive layers bulging into the gaps between the coil patterns to ensure high flatness and prevent short-circuit failures, and includes a magnetic member and metal member for enhanced performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If the substrate is removed to achieve thinning of the antenna module, then the thickness is reduced, but large irregularity occurs in the adhesive layer causing loss of flatness

Engineering Contradiction:

ImprovethicknessVSAvoidflatness

Core Design Contradiction:

Length of moving objectVSShape

Solution Approach 1:

The adhesive layer is applied to the coil pattern before substrate removal, and its thickness is controlled to bulge toward the gap between patterns. This preliminary action ensures that when the substrate is removed, the adhesive layer already has the proper profile to maintain flatness without requiring post-processing adjustments

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The adhesive layer is designed with non-uniform thickness, bulging toward the gap between patterns rather than being uniformly thick. This local variation in adhesive thickness compensates for the irregularities that would otherwise occur after substrate removal, maintaining overall flatness while enabling thinning

Inventive Principle:

Principle #3Local quality

2Reliability

If the adhesive layer is applied thickly to ensure coverage, then adhesion is improved, but flatness is lost due to large irregularity

Engineering Contradiction:

ImproveadhesionVSAvoidflatness

Core Design Contradiction:

ReliabilityVSShape

Solution Approach 1:

The adhesive layer thickness is varied locally - thicker in areas where it bulges toward the gap between patterns for enhanced adhesion, and thinner in other areas to maintain overall flatness. This selective thickness distribution achieves both strong adhesion and flat surface

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The adhesive layer is applied with excessive thickness in specific regions (bulging toward gaps) to ensure sufficient adhesion coverage, while the overall structure is designed to manage this excess material without compromising flatness

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS20230275351A1Antenna module

Publication Date: 2023.08.31 TDK CORP

AI summary

Disclosed herein is an antenna module that includes a coil pattern planarly wound in a plurality of turns; a first adhesive layer attached to a first surface of the coil pattern in an axial direction of the coil pattern; a second adhesive layer attached to a second surface of the coil pattern in the axial direction of the coil pattern, the second surface being opposite to the first surface; and a magnetic member attached to the first adhesive layer such that the first adhesive layer is sandwiched between the coil pattern and the magnetic member. The first and second adhesive layers bulge to a gap between adjacent patterns of the coil pattern.