Light Source With Inclined Substrate For Position Measuring Device

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Solution Overview

Problem

Existing position measuring devices face challenges in producing high-quality light sources for sensor units that are both economically viable and capable of precise position measurement.

Innovation Solution

A light source for position measuring devices is developed, featuring an electrically conductive substrate with inclined or offset surfaces, a semiconductor layer structure for emitting light, and an electrically conductive layer making contact with the substrate, along with electrical connections that allow orthogonal light emission, eliminating the need for wire bonding and incorporating a heat sink for thermal management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If wire bonding is used to establish electrical connections, then reliable electrical contact can be achieved, but the manufacturing complexity and production time increase

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent removes the wire bonding step from the manufacturing process by integrating electrical connections directly into the substrate structure. The substrate includes conductive traces and contact pads that establish electrical connections without requiring separate wire bonding operations, thereby simplifying the manufacturing process while maintaining connection reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The substrate serves multiple functions by combining the mechanical support function with the electrical connection function. The substrate includes both structural elements and integrated conductive pathways, merging what were previously separate components (substrate and wire bonds) into a single integrated structure that reduces manufacturing steps.

Inventive Principle:
Principle #5Merging (Combining)

2Measurement precision

If the light source is optimized for precise position measurement, then measurement precision improves, but the manufacturing cost increases

Engineering Contradiction:
Improveposition measurement precisionVSAvoidmanufacturing cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The substrate is designed to serve multiple functions simultaneously: it provides mechanical support for the semiconductor layer structure, establishes electrical connections through integrated conductive traces, manages heat dissipation through thermal pathways, and enables precise positioning of the light-emitting elements. This multi-functionality reduces the need for separate specialized components, thereby lowering manufacturing costs while maintaining measurement precision.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent optimizes the substrate geometry with inclined or offset surfaces that change the spatial parameters of light emission. These parameter changes enable the light source to achieve optimal illumination angles for precise position measurement while using standard manufacturing processes, avoiding the need for expensive custom fabrication.

Inventive Principle:
Principle #35Parameter changes

3Illumination intensity

If the substrate has inclined or offset surfaces for optimized light emission, then light directionality improves, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvelight directionalityVSAvoidsurface orientation precision
Core Design Contradiction:
Illumination intensityVSManufacturing precision

Solution Approach 1:

The substrate incorporates asymmetric inclined or offset surfaces that are designed to provide optimized light emission angles. These asymmetric features are integrated into the substrate geometry and can be manufactured using standard precision machining or molding processes, achieving the required surface orientation precision without requiring ultra-precise manufacturing capabilities.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The substrate geometry with inclined surfaces is pre-designed and pre-manufactured as part of the base substrate structure before the semiconductor layer is applied. This preliminary action allows the light directionality to be optimized in advance, and the semiconductor layer can then be positioned on this pre-prepared substrate, reducing the precision requirements for subsequent assembly steps.

Inventive Principle:
Principle #10Preliminary action

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 solution enables the production of high-quality light sources that facilitate precise position measurements in position measuring devices, ensuring reliable and cost-effective operation by eliminating the need for wire bonding and enhancing thermal management.

Implementation Method 1

a semiconductor layer structure (2) which is intended for emitting light and is applied to or on the first surface (1.1)

Methodology Applied
Scientific EffectLight emission from semiconductor layer structure: Light Emitting Diode

Implementation Method 2

incorporating a heat sink for thermal management

Methodology Applied
Scientific EffectThermal management: Heat Sink

Data Source

PatentEP3745090B1Light source and method for producing the same and position measuring device comprising a light source
Publication Date: 2021.07.14 DR JOHANNES HEIDENHAIN GMBH
  • EP3745090B1 patent drawingFigure 1~3
  • EP3745090B1 patent drawingFigure 4~6
  • EP3745090B1 patent drawingFigure 7~8

AI summary

The invention relates to a light source (L) for a sensor unit of a position measuring device. The light source (L) comprises an electrically conductive substrate (1) having a first surface (1.1) and further surfaces (1.2 to 1.6), wherein at least one of the further surfaces (1.2 to 1.6) is inclined or offset relative to the first surface (1.1), and a semiconductor layer structure (2) applied to the first surface (1.1). The light source (L) further comprises an electrically conductive layer (3; 30) which contacts the substrate (1) at at least one of the further surfaces (1.2 to 1.6), and a first electrical connection (4) and a second electrical connection (5). The first electrical connection (4) is connected to the electrically conductive layer (3; 30), and the second electrical connection (5) is connected to the semiconductor layer structure (2), with both connections (4, 5) being located on the first side (S) of the light source (L).Furthermore, the invention relates to a method for manufacturing such a light source (L) and a position measuring device with such a light source (L).