Quartz Glass Cavity Package With Mirror-Rough Surfaces for UV Reliability

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Solution Overview

Problem

Existing methods for manufacturing synthetic quartz glass cavity members and optical device packages face challenges in achieving precise dimensional accuracy and stress-free bonding, particularly when using high-purity SiO2 materials, and are prone to degradation and breakage under short-wavelength light and heat exposure.

Innovation Solution

A synthetic quartz glass cavity member with a mirror surface and rough surface structure is bonded to a substrate using a metal-base adhesive layer, formed by drilling through-holes in a quartz glass substrate and applying a metal-base paste, which is then heated to create a B-staged adhesive layer for improved bonding and heat resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If etching method is used to form cavity structure, then cavity opening can be formed, but dimensional accuracy deteriorates due to rounding of opening

Engineering Contradiction:
Improvedimensional accuracy of cavity openingVSAvoidrounding of cavity opening
Core Design Contradiction:
Manufacturing precisionVSShape

Solution Approach 1:

The patent replaces the chemical etching process with a mechanical drilling process to form the cavity opening. This substitution eliminates the rounding effect inherent in etching and achieves precise dimensional control of the cavity opening, directly resolving the contradiction between manufacturability and shape accuracy.

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

2Strength

If anodic bonding is used to bond glass members, then bonding can be achieved, but it cannot be employed with synthetic quartz glass

Engineering Contradiction:
Improvebonding capabilityVSAvoidcompatibility with synthetic quartz glass
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The patent changes the bonding parameters by using eutectic bonding at lower temperatures (around 400-500°C) instead of anodic bonding. This parameter change enables successful bonding of synthetic quartz glass, which is incompatible with traditional anodic bonding methods, thereby resolving the contradiction between bonding strength and material adaptability.

Inventive Principle:
Principle #35Parameter changes

3Strength

If organic adhesives are used for bonding, then bonding can be achieved, but heat resistance deteriorates

Engineering Contradiction:
Improvebonding capabilityVSAvoidheat resistance
Core Design Contradiction:
StrengthVSTemperature

Solution Approach 1:

The patent uses eutectic bonding, which creates a composite bonding interface with metal intermetallic compounds formed at the bonding surface. This composite structure provides both strong bonding capability and excellent heat resistance, resolving the contradiction between bonding strength and temperature resistance that plagues organic adhesive systems.

Inventive Principle:
Principle #40Composite materials

4Length of stationary object

If dry etching is used to drill deep recesses, then deep cavity can be formed, but processing time and cost increase

Engineering Contradiction:
Improvecavity depthVSAvoidprocessing time
Core Design Contradiction:
Length of stationary objectVSLoss of time

Solution Approach 1:

The patent replaces the time-consuming dry etching process with a mechanical drilling process that can rapidly create deep cavity structures. This mechanical approach significantly reduces processing time and cost while achieving the required cavity depth, resolving the contradiction between cavity depth and manufacturing efficiency.

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

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 enhances the long-term reliability and UV resistance of optical device packages by reducing stress and degradation, allowing for efficient light extraction and maintaining structural integrity under heat and UV exposure.

Implementation Method 1

applying a metal-base paste, which is then heated to create a B-staged adhesive layer for improved bonding

Methodology Applied
Scientific EffectHeating: Heating

Data Source

PatentEP3599414B1Synthetic quartz glass cavity member, synthetic quartz glass cavity lid, optical device package, and making methods
Publication Date: 2024.09.04 SHIN ETSU CHEMICAL CO LTD
  • EP3599414B1 patent drawingFigure 1
  • EP3599414B1 patent drawingFigure 2
  • EP3599414B1 patent drawingFigure 3

AI summary

A synthetic quartz glass cavity member (1) is bonded to a substrate (6) having an optical device (7) mounted thereon such that the device may be accommodated in the cavity member. The cavity member (1) has an inside surface consisting of a top surface (2a) opposed to the device (7) and a side surface (3a). The top surface (2a) is a mirror surface and the side surface (3a) is a rough surface.