Solid-State Spectrometer Dual Shadow Mask Wavelength Selectivity

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Solution Overview

Problem

Current spectrometers face challenges in producing precise, energy-selective optical functional elements at a low cost, particularly in achieving high precision and small feature sizes required for wavelength-selective sensor elements using CMOS technology.

Innovation Solution

A solid-state spectrometer design featuring two perforated masks with overlapping windows, where the distance between holes in the masks varies, creating radiation transmission openings of different sizes, allowing for precise wavelength selectivity and mass production using CMOS technologies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single shadow mask with pinholes is used for wavelength selection, then the device structure is simple, but the manufacturing precision and reproducibility are difficult to achieve

Engineering Contradiction:
Improvestructure simplicityVSAvoidshadow mask precision
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The single shadow mask is divided into two separate shadow masks (first and second shadow masks), each with its own set of pinholes. This segmentation allows each mask to be manufactured with standard precision, while the combination of both masks creates the fine wavelength-selective apertures. The segmentation resolves the contradiction by trading structural simplicity for manufacturability without sacrificing precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The solution moves from a single-plane (2D) shadow mask to a multi-plane (3D) arrangement with two shadow masks separated by a distance. This dimensional change allows the wavelength selection to be achieved through the combined effect of pinholes in different planes, enabling precise wavelength control while using standard manufacturing processes for each individual mask.

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

2Manufacturing precision

If high-precision shadow masks are manufactured, then wavelength selectivity is achieved, but the production cost increases

Engineering Contradiction:
Improvewavelength selectivityVSAvoidproduction cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

By dividing the precision requirement into two separate masks with relaxed tolerances, the overall system achieves the required wavelength selectivity without incurring the high costs associated with manufacturing a single ultra-precise mask. Each mask can be produced using standard, cost-effective processes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the parameter of precision distribution - instead of concentrating all precision requirements in one mask, the precision is distributed across two masks with less stringent individual requirements. This parameter change enables cost-effective manufacturing while maintaining the necessary wavelength-selective performance.

Inventive Principle:
Principle #35Parameter changes

3Volume of moving object

If smaller feature sizes are used for wavelength selection, then the spectrometer format is reduced, but the manufacturing difficulty increases

Engineering Contradiction:
Improvespectrometer sizeVSAvoidfeature size precision
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The invention uses the third dimension (distance between the two shadow masks) to achieve wavelength selection without requiring extremely small feature sizes in a single plane. The interplay between pinholes in different planes creates the fine effective aperture, enabling compact spectrometer design with manufacturable feature dimensions.

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

Solution Approach 2:

The segmentation of the aperture formation process into two separate masks allows each mask to have larger, more manufacturable pinholes, while the combination produces the fine effective aperture needed for compact spectrometer design. This resolves the contradiction between small size and manufacturing feasibility.

Inventive Principle:
Principle #1Segmentation

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 design enables the production of spectrometers with high precision and low cost, ensuring wavelength selectivity within the desired range, facilitating applications in various fields such as liquid monitoring, gas detection, and DNA analysis.

Implementation Method 1

The two shadow masks are arranged relative to each other in such a way that their windows more or less overlap... so that the degree of overlap between adjacent windows in the two shadow masks varies. This results in holes or radiation transmission openings of different sizes

Methodology Applied
Scientific EffectDiffraction: Diffraction

Data Source

PatentEP2521179B1Device for recording the spectrum of electromagnetic radiation within a pre-defined wavelength range
Publication Date: 2015.10.07 ELMOS SEMICON AG
  • EP2521179B1 patent drawingFigure 1
  • EP2521179B1 patent drawingFigure 2
  • EP2521179B1 patent drawingFigure 3

AI summary

The device for detecting the spectrum of electromagnetic radiation within a predetermined wavelength range is provided with a substrate (12), a first shadow mask (20) arranged above the substrate (12) made of a material opaque to radiation within the predetermined wavelength range, wherein the first shadow mask (20) has a plurality of first windows (22), a plurality of sensor elements arranged in the substrate (12) which are sensitive to radiation within the predetermined wavelength range, and a second shadow mask (32) arranged above the first shadow mask (20) which has second windows (36) and is made of a material opaque to radiation within the predetermined wavelength range.The second windows (36) of the second aperture mask (32) are arranged overlapping with the windows of the first aperture mask (20), and opposite edges of each pair of overlapping windows of the two aperture masks (20, 32) define the size of a radiation transmission aperture (42) assigned to a sensor element for transmitting radiation within the specified wavelength range to the sensor element located below the radiation transmission aperture (42). At least one radiation transmission aperture (42) with a size corresponding to one of the wavelengths of interest is provided for detecting the intensity of electromagnetic radiation at each wavelength of interest within the specified wavelength range.