Quartz Window Material With Rough Surface for UV Light Distribution

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current window materials for ultraviolet LEDs, particularly in the deep ultraviolet region, face challenges in shaping synthetic quartz glass into lens forms due to its difficulty in processing, and existing antireflection methods fail to reliably control light distribution and maintain high total light transmittance over time.

Innovation Solution

A window material comprising a synthetic quartz glass substrate with a flat plate shape and a three-layer antireflection film, including Al2O3, HfO2, and MgF2 or SiO2 thin films, which provides a rough surface for effective light scattering and high total light transmittance, facilitating easy processing and long-term stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If synthetic quartz glass is used as window material for UV-LED sealing, then good transmittance of short-wavelength light is achieved, but difficulty in cutting and shaping into lens form increases

Engineering Contradiction:
Improvelight transmittanceVSAvoiddifficulty in cutting and shaping
Core Design Contradiction:
Illumination intensityVSEase of manufacture

Solution Approach 1:

The patent divides the window material into two functional parts: a synthetic quartz glass substrate for UV transmittance and a resin layer for light distribution control. This segmentation allows each material to perform its optimal function without requiring the quartz glass to be difficultly shaped into a lens form.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The resin layer acts as an intermediary between the quartz glass substrate and the external environment. It provides the light distribution control function that would otherwise require complex shaping of the quartz glass, while the quartz glass maintains its simple flat plate shape for easy manufacturing.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Shape

If a lens-shaped window material is formed to control light distribution properties, then light distribution control is improved, but manufacturing complexity and cost increase

Engineering Contradiction:
Improvelight distribution controlVSAvoidmanufacturing complexity
Core Design Contradiction:
ShapeVSDevice complexity

Solution Approach 1:

The patent separates the light distribution control function from the structural window material by introducing a dedicated resin layer. This allows the window to maintain a simple flat plate shape while achieving lens-like light distribution control through the resin layer's refractive properties.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent controls light distribution by adjusting parameters of the resin layer such as its refractive index, thickness, and positioning relative to the LED chip, rather than changing the physical shape of the entire window assembly. This provides manufacturing simplicity while achieving optical control.

Inventive Principle:
Principle #35Parameter changes

3Illumination intensity

If antireflection film is deposited on quartz surface to improve transmittance, then theoretical reflectance reduction is achieved, but reliability for total light transmittance in actual use is insufficient

Engineering Contradiction:
Improveparallel light transmittanceVSAvoidtotal light transmittance reliability
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The patent changes the approach from depositing antireflection films to controlling the refractive index and thickness parameters of a resin layer. This parameter-based control provides more reliable and predictable total light transmittance performance in actual LED applications.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The resin layer serves as an intermediary that optimizes light transmission from the LED chip through the window. Its refractive index is selected to match or complement the quartz glass, minimizing reflections at interfaces and maximizing total light transmittance without requiring complex antireflection film structures.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Illumination intensity

If moth-eye antireflection structure with silica particles is used, then ultraviolet light reflection is inhibited, but degree of freedom in controlling light distribution properties is limited

Engineering Contradiction:
Improveultraviolet light transmittanceVSAvoidlight distribution control flexibility
Core Design Contradiction:
Illumination intensityVSAdaptability or versatility

Solution Approach 1:

The patent separates the antireflection function (achieved through resin layer refractive index control) from the light distribution control function (achieved through resin layer thickness and positioning). This segmentation provides flexibility in optimizing both functions independently.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses parameter control (refractive index, thickness, positioning) of the resin layer to achieve both antireflection and light distribution control, providing greater adaptability and versatility compared to fixed moth-eye structures.

Inventive Principle:
Principle #35Parameter changes

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 enables reliable control of light distribution properties, maintains high total light transmittance, and ensures long-term stability, making it suitable for ultraviolet LEDs, particularly in the deep ultraviolet region.

Implementation Method 1

at least one of the main surfaces being a rough surface

Methodology Applied
Scientific EffectLight scattering: Scattering

Implementation Method 2

an antireflection film formed on the at least one main surface of the synthetic quartz glass substrate

Methodology Applied
Scientific EffectAntireflection: Anti-Reflective Coating

Data Source

PatentEP4403532A1Window material for optical element, lid for optical element package, and optical element package
Publication Date: 2024.07.24 SHIN ETSU CHEMICAL CO LTD
  • EP4403532A1 patent drawingFigure 1~2
  • EP4403532A1 patent drawingFigure 3~4
  • EP4403532A1 patent drawingFigure 5~6

AI summary

A window material for an optical element, including: a synthetic quartz glass substrate having a flat plate shape and having main surfaces through which light is transmitted, at least one of the main surfaces being a rough surface; and an antireflection film formed on the at least one main surface of the synthetic quartz glass substrate, the main surface being the rough surface. The window material for an optical element of the present invention is easy in shape processing, undergoes little temporal change in a wide wavelength region and is stable over a long period of time, and has high total light transmittance of distributed light.