RFID Antenna Foil Release Using Selective Thermal Insulation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The existing methods for manufacturing RFID antennas face challenges in ensuring proper registration and alignment during the cutting process, leading to potential detachment of foil portions and resulting in defective antennas.

Innovation Solution

The method involves applying an adhesive to a substrate, securing a conductor in the shape of an antenna, defining a thermal gap to isolate inner and outer regions, and applying heat to the outer region to melt the adhesive between the outer conductor and substrate without affecting the inner region, allowing for precise release of the outer conductor while keeping the inner conductor secured.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If heat is applied to the conductor to release the adhesive, then the adhesive between the outer region and substrate melts allowing easy detachment, but the adhesive between the inner region and substrate also melts causing the antenna to detach from the substrate

Engineering Contradiction:

Improveease of conductor releaseVSAvoidantenna attachment integrity

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The conductor is divided into an inner region (antenna) and an outer region (excess material) by introducing a gap. This segmentation allows selective thermal treatment where heat applied to the outer region does not transfer to the inner region, enabling independent control of adhesive melting in each zone. The gap acts as a thermal barrier that prevents unwanted heat conduction to the antenna portion.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The adhesive layer is given different thermal properties in different regions by using the gap to isolate thermal zones. The outer region adhesive is designed to melt at a specific temperature when heat is applied locally, while the inner region adhesive remains below its melting point. This local differentiation of thermal response allows selective release of excess conductor without affecting the antenna.

Inventive Principle:

Principle #3Local quality

2Manufacturing precision

If cutting is used to form the antenna shape from foil, then the antenna can be formed with precise shape, but proper registration and alignment are difficult to ensure leading to defective antennas

Engineering Contradiction:

Improveantenna shape precisionVSAvoidalignment and registration complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

Instead of cutting the foil to the final antenna shape, the process applies adhesive in the desired antenna pattern first, then laminates a larger foil over it. The gap is created by not applying adhesive in certain areas, which automatically defines the antenna boundaries without requiring precise cutting alignment. This preliminary adhesive application serves as a template that simplifies subsequent processing.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The complex cutting and alignment operation is replaced by extracting only the necessary portion of the foil through selective adhesive application. The adhesive pattern itself defines the antenna shape, and excess foil is simply removed after lamination without requiring precise cutting registration. This extracts the essential antenna-forming function from the complex cutting process.

Inventive Principle:

Principle #2Taking out (Extraction)

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 ensures accurate and efficient formation of RFID antennas by preventing the inner adhesive from melting, thus maintaining the integrity of the antenna structure and reducing defects, while allowing for easy detachment of the outer conductor from the substrate.

Implementation Method 1

heat is applied to the outer region of the conductor so as to cause at least a portion of the adhesive positioned between the outer region of the conductor and the substrate to melt (or other phase or state change) without causing at least a portion of the adhesive positioned between the inner region of the conductor and the substrate to melt (or other phase or state change) due to the presence of the gap

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

A gap is defined in the conductor (which can be in the shape of an antenna) so as to isolate an inner region of the conductor from an outer region of the conductor

Methodology Applied

Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 3

Methodology Applied

Scientific EffectMelting: Melting

Data Source

PatentUS11809938B2Selective thermal insulation in manufacture of antennas for RFID devices

Publication Date: 2023.11.07 AVERY DENNISON RETAIL INFORMATION SERVICES LLC

AI summary

The antenna of an RFID device is formed by applying an adhesive to a substrate. A conductor is secured to the substrate using the adhesive and then a gap is defined in the conductor in the shape of an antenna so as to isolate an inner region of the conductor from an outer region of the conductor. Heat is applied to the outer region of the conductor so as to cause at least a portion of the adhesive positioned between the outer region of the conductor and the substrate to undergo a phase change or be activated without causing at least a portion of the adhesive positioned between the inner region of the conductor and the substrate to undergo a phase change or be activated. The outer region of the conductor is then dissociated from the substrate, with the inner region of the conductor remaining secured to the substrate by the adhesive as an antenna.