Integrated Lid Temperature Sensor for IR Signal Cancellation

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Solution Overview

Problem

Existing temperature sensor modules face issues with spurious IR-radiation interference due to incomplete transmission of object IR-radiation through the lid structure, self-emission from the lid and aperture, and increased costs and tolerances in assembly processes, leading to suboptimal measurement accuracy and increased product dimensions.

Innovation Solution

A temperature sensor module with an integrated lid structure and a second temperature sensor fabricated using a CMOS process, where the lid-integrated temperature sensor is connected to the sensor-interface control IC, forming a complete lid and enabling electrical connections within the package, allowing for improved IR-radiation filtering and thermal signal cancellation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a lid structure with aperture is used to limit field of view, then measurement precision is improved, but spurious IR-radiation interference increases due to incomplete transmission and self-emission from the lid

Engineering Contradiction:
Improvetemperature measurement accuracyVSAvoidspurious IR-radiation interference
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

A second temperature sensor is introduced as an intermediary element to measure the lid temperature separately. This mediator enables the system to distinguish between the lid's thermal emission and the object's IR radiation, allowing for compensation and improved measurement accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The lid temperature measured by the second sensor is fed back to the signal processing unit, which uses this information to compensate for the lid's thermal emission. This feedback mechanism allows the system to correct for spurious IR-radiation interference and maintain measurement precision.

Inventive Principle:
Principle #23Feedback

2Ease of manufacture

If multiple separate components are used for lid structure, then manufacturing flexibility is improved, but assembly costs and tolerances increase

Engineering Contradiction:
Improvemanufacturing flexibilityVSAvoidassembly process complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The second temperature sensor is integrated directly into the lid structure, merging two previously separate components (lid and temperature sensor) into a single unified element. This integration simplifies the assembly process, reduces the number of parts, and lowers manufacturing complexity while maintaining manufacturing flexibility.

Inventive Principle:
Principle #5Merging (Combining)

3Measurement precision

If the lid structure is made more complex to filter IR-radiation, then measurement precision is improved, but device complexity and manufacturing costs increase

Engineering Contradiction:
ImproveIR-radiation filtering accuracyVSAvoidlid structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Instead of using complex mechanical or physical filter structures to block IR-radiation, the patent substitutes a electronic signal processing approach. The second temperature sensor provides thermal information that is processed electronically to compensate for lid emission, replacing the need for complex physical filtering mechanisms.

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 design maximizes the transmission of relevant IR-radiation from the object while minimizing spurious IR-radiation interference, reducing assembly costs and tolerances, and enhancing measurement accuracy by integrating all lid functionalities within a single sub-component, allowing for effective cancellation of interfering thermal signals.

Implementation Method 1

the IR-(infrared) emission of an object's surface is detected and evaluated in order to deduce the object's effective temperature

Methodology Applied
Scientific EffectInfrared radiation detection: Infrared Radiation

Implementation Method 2

The respectively detecting element or temperature sensing element can be a so-called thermocouple or thermopile sensor element which generally converts the infrared (IR)-radiation emitted by the object-under-test's surface or object of interest, collected by the sensing element, into an electrical voltage

Methodology Applied
Scientific EffectThermopile effect: Thermopile

Implementation Method 3

The sensor module lid structure that can be formed by e.g. an IR-filter and an aperture, serves the purpose to limit the field of view of the temperature sensing element, to filter out all un-wanted light and IR-radiation and to transmit the wanted IR-radiation to the sensing element inside the sensor housing

Methodology Applied
Scientific EffectInfrared transmission: Infrared Radiation

Implementation Method 4

This integrated circuit processes the thermopile output voltage and comprises an integrated on-chip temperature sensor for measuring the ambient temperature T amb , i.e. the temperature on the backside of the sensor element

Methodology Applied
Scientific EffectTemperature sensing:

Implementation Method 5

the sensor module lid structure that can be formed by e.g. an IR-filter and an aperture, serves the purpose to limit the field of view of the temperature sensing element, to filter out all un-wanted light and IR-radiation

Methodology Applied
Scientific EffectRadiation blocking: Absorption (EM radiation)

Data Source

PatentEP3483575B1Temperature sensor module with integrated lid structure for spurious IR-cancellation
Publication Date: 2023.01.04 IDT EURO GMBH
  • EP3483575B1 patent drawingFigure 1~2
  • EP3483575B1 patent drawingFigure 3
  • EP3483575B1 patent drawingFigure 4~5C

AI summary

The invention discloses a temperature sensor module with an integrated lid structure for spurious IR-cancellation. The objective to provide an improved temperature sensor module which allows to detect a maximum of the relevant IR-radiation from an object's surface of interest as well as to generate additional information about parasitic or spurious IR-radiation that distort the relevant thermal signal in order to enable a cancellation of interfering thermal signal portions will be solved by a temperature sensor module comprising a temperature sensing element, a sensor-interface control integrated circuit, whereas the temperature sensing element is coupled to the sensor-interface control IC, and a lid structure and a sensor packaging both defining a field of view of the temperature sensor module, wherein the lid structure is formed by a substrate comprising a second integrated temperature sensor connected to the sensor-interface control IC or an external connected processing unit.(Fig. 4)