Double-Layer Stencil for Wavelength Conversion Plate Fabrication

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Solution Overview

Problem

Conventional methods for producing conversion plates, such as screen printing, are limited by layer thickness to around 40 μm, leading to variations in contour and reproducibility, which restricts the use of high-thickness conversion materials with optimized properties like efficiency and long-term stability.

Innovation Solution

A method using a double-layer stencil with a two-stage lithographic and nickel-galvanic process to produce conversion plates with layer thicknesses between 60 μm and 170 μm, allowing for improved reproducibility and edge fidelity, enabling the use of conversion substances with enhanced properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If screen printing process is used, then production is simple and conventional, but layer thickness is limited to around 40 μm and reproducibility is poor

Engineering Contradiction:
Improvelayer thickness controlVSAvoidproduction process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The stencil is divided into two separate layers: a support layer providing mechanical stability and a pattern layer defining the conversion plate geometry. This segmentation allows each layer to be optimized independently - the support layer can be made thicker (80-150 μm) to enable greater conversion plate thickness while the pattern layer maintains precise dimensional control

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from conventional single-layer screen printing to a two-layer stencil system, adding a vertical dimension to the stencil structure. This dimensional change enables the support layer to provide mechanical strength for thicker applications while the pattern layer maintains printing precision

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

2Length of stationary object

If conventional screens with maximum 40 μm thickness are used, then screen printing is feasible, but high layer thicknesses of conversion plates cannot be achieved

Engineering Contradiction:
Improveconversion plate thicknessVSAvoidcontour accuracy
Core Design Contradiction:
Length of stationary objectVSManufacturing precision

Solution Approach 1:

By segmenting the stencil into support and pattern layers, the support layer can be made sufficiently thick (80-150 μm) to accommodate and print thicker conversion plates (60-170 μm), while the pattern layer maintains the precision needed for accurate contour reproduction

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The two-layer stencil functions as a composite structure where the support layer provides mechanical properties (thickness, strength) and the pattern layer provides functional properties (dimensional accuracy, shape definition). This composite approach allows both thick conversion plates and precise contours to be achieved simultaneously

Inventive Principle:
Principle #40Composite materials

3Reliability

If screen printing is used, then production process is conventional, but reproducibility of dimensions and shapes varies disadvantageously

Engineering Contradiction:
ImprovereproducibilityVSAvoidstencil structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The two-layer stencil structure separates the functions of mechanical support and pattern definition, allowing the pattern layer to be optimized specifically for dimensional accuracy and shape reproduction. This functional separation improves reproducibility despite increased structural complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the structural parameter of the stencil from single-layer to two-layer configuration. This parameter change enables improved reproducibility by allowing independent optimization of each layer's properties - the pattern layer can be made thinner and more precise while the support layer provides necessary mechanical stability

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2630668B1Method of fabricating a wavelength-conversion plate
Publication Date: 2021.05.05 OSRAM OPTO SEMICON GMBH & CO OHG
  • EP2630668B1 patent drawingFigure 1A~1C
  • EP2630668B1 patent drawingFigure 2A~2C
  • EP2630668B1 patent drawingFigure 3A~4B

AI summary

A method for producing at least one conversion lamina (4) for a radiation-emitting semiconductor component is specified, wherein a base material (3) comprising conversion substance contained therein is applied to a substrate (2) by means of a double-layered stencil (1). Furthermore, a conversion lamina (4) for a radiation-emitting semiconductor component is specified, which comprises a base material (3) and a conversion substance embedded therein, wherein the thickness (D2) of the conversion lamina (4) is in a range of between 60 µm and 170 µm inclusive.