Oblique UV Curing for Shadowed Adhesive in X-ray Detectors

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Solution Overview

Problem

In the manufacture of large medical X-ray detectors, the use of opaque substrates with different thermal expansion coefficients and ultraviolet-cured adhesives poses a challenge as the opaque substrates block UV light, leading to incomplete curing of the adhesive layer in shadowed regions, which can result in mechanical stress and reduced reliability.

Innovation Solution

Directing actinic rays, such as ultraviolet light, at an oblique angle into the adhesive layer through openings in the supporting frame, allowing for internal reflection and curing of the adhesive in shadowed areas, ensuring complete curing and reducing mechanical stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If UV light is applied through openings in the frame to cure the adhesive layer, then the adhesive in the openings is cured, but the adhesive in the shadow of the grid members remains uncured or partially cured

Engineering Contradiction:
Improvecuring completenessVSAvoidshadowed uncured regions
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies UV light from multiple dimensions/angles rather than a single perpendicular direction. By using oblique incidence angles and multiple illumination directions, the light can reach into shadowed regions that would be inaccessible from a single angle, thereby curing adhesive in previously unreachable areas.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent employs asymmetric illumination patterns where UV light is directed at various oblique angles rather than symmetric perpendicular illumination. This asymmetric approach allows light to penetrate shadowed regions created by the grid structure, enabling complete curing of adhesive throughout the bonding interface.

Inventive Principle:
Principle #4Asymmetry

2Strength

If opaque substrates are used in the detector assembly, then mechanical strength and thermal expansion matching are improved, but UV light transmission is blocked preventing adhesive curing

Engineering Contradiction:
Improvemechanical strengthVSAvoidUV light transmission
Core Design Contradiction:
StrengthVSUse of energy by moving object

Solution Approach 1:

The patent converts the harmful effect of opaque substrates blocking UV light into a beneficial solution by using oblique illumination. The same opaque substrates that block perpendicular light can be circumvented by directing light at oblique angles, allowing the substrate's mechanical strength benefits to be retained while achieving adhesive curing through alternative light paths.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

By changing the dimension of light incidence from perpendicular to oblique angles, the patent enables UV light to reach adhesive layers that are shadowed by opaque substrates, maintaining both the mechanical benefits of opaque materials and the curing functionality.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Manufacturing precision

If thermal curing is used instead of UV curing, then complete curing of shadowed regions is achieved, but manufacturing throughput time increases and mechanical stress builds up

Engineering Contradiction:
Improvecuring completenessVSAvoidmanufacturing throughput time
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent replaces thermal curing (which relies on heat diffusion through materials) with UV photopolymerization (which uses light absorption and immediate chemical reaction). By using oblique UV illumination, the system achieves complete curing without the time delays and thermal stress associated with thermal curing processes.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

By using multi-angle UV illumination instead of thermal curing, the patent achieves complete adhesive curing rapidly at room temperature, avoiding both the extended processing time and thermal stress buildup that would result from using thermal curing methods.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 method ensures complete curing of the adhesive layer, enhancing the mechanical strength and reliability of the X-ray detector by effectively addressing the issue of incomplete curing due to shadowed regions, thereby improving the manufacturing process and detector performance.

Implementation Method 1

directing actinic rays obliquely through the openings so that they are reflected internally into the part of the adhesive layer in the shadow of the opaque portions

Methodology Applied
Scientific EffectInternal reflection: Reflection

Implementation Method 2

an adhesive layer, which is cured by the application of ultraviolet light

Methodology Applied
Scientific EffectUV light curing: Photopolymerisation

Data Source

PatentEP3172453B1Bonding method with curing by reflected actinic rays
Publication Date: 2021.04.28 TELEDYNE DIGITAL IMAGING INC(CA)
  • EP3172453B1 patent drawingFigure 1~2

AI summary

A method of making a device having a component with a planar surface bonded to a supporting frame with openings therein by an adhesive layer cured by actinic rays, wherein part of the adhesive layer lies in the shadow of opaque portions of the supporting frame, involves bringing the component and supporting frame together with a layer of adhesive applied between them. The part of the adhesive layer in the shadow of the opaque portions is cured by directing actinic rays obliquely through the openings so that they are reflected internally into the part of the adhesive layer in the shadow of the opaque portions.