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Surface Temperature Measurements: Thermocouple Mounting Position
2023.06.07
Points of this article
・The thermocouple mounting position is also important for accurate measurement of TT.
・Even millimeter-unit shifts can result in temperature differences.
The position at which a thermocouple is mounted is also important for accurate TT measurement.
Thermocouple Mounting Position
Because TT is defined as the temperature at the center of the upper surface of a package, the center of the upper surface of the package must be identified as the position for mounting the thermocouple, and the tip (junction) of the thermocouple must be mounted precisely at that position. If the actual mounted position differs, TT will be different. The diagram below shows the results of simulations of the temperature distribution over the surface of a package. The thermal conductivity of package sealing resins ranges from approximately 0.3 to 1 W/mk, so that even millimeter-level shifts can result in temperature differences. The table shows the temperatures at points A to E in the diagram.
【Download Documents】 Thermal Design of Semiconductor Components in Electronics
Thermal design has become a new issue in the design of electronic equipment in recent years, as thermal countermeasures have been the focus of attention. Although heat has been an important consideration for some time, the requirements for electronic equipment have changed in recent years, making it necessary to review conventional thermal countermeasures. This handbook describes thermal design based on the assumption that ICs and transistors are basically used in electronic equipment.
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Electrical Circuit Design
- Soldering Techniques and Solder Types
- Seven Tools for Soldering
- Seven Techniques for Printed Circuit Board Reworking
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Basic Alternating Current (AC)
- AC Circuits: Alternating Current, Waveforms, and Formulas
- Complex Numbers in AC Circuit
- Electrical Reactance
- What is Impedance? AC Circuit Analysis and Design
- Impedance Measurement: How to Choose Methods and Improve Accuracy
- Impedance Matching: Why It Matters for Power Transfer and Signal Reflections
- Resonant Circuits: Resonant Frequency and Q Factor
- RLC Circuit: Series and Parallel, Applied circuits
- What is AC Power? Active Power, Reactive Power, Apparent Power
- Power Factor: Calculation and Efficiency Improvement
- What is PFC?
- Boundary Current Mode (BCM) PFC: Examples of Efficiency Improvement Using Diodes
- Continuous Current Mode (CCM) PFC: Examples of Efficiency Improvement Using Diode
- LED Illumination Circuits：Example of Efficiency Improvement and Noise Reduction Using MOSFETs
- PFC Circuits for Air Conditioners：Example of Efficiency Improvement Using MOSFETs and Diodes
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Basic Direct Current (DC)
- Ohm’s Law: Voltage, Current, and Resistance
- Electric Current and Voltage in DC Circuits
- Kirchhoff’s Circuit Laws
- What Is Mesh Analysis (Mesh Current Method)?
- What Is Nodal Analysis (Nodal Voltage Analysis)?
- Thevenin’s Theorem: DC Circuit Analysis
- Norton’s Theorem: Equivalent Circuit Analysis
- What Is the Superposition Theorem?
- What Is the Δ–Y Transformation (Y–Δ Transformation)?
- Voltage Divider Circuit
- Current Divider and the Current Divider Rule
Thermal design
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About Thermal Design
- Changes in Engineering Trends and Thermal Design
- A Mutual Understanding of Thermal Design
- Fundamentals of Thermal Resistance and Heat Dissipation: About Thermal Resistance
- Fundamentals of Thermal Resistance and Heat Dissipation: Heat Transmission and Heat Dissipation Paths
- Fundamentals of Thermal Resistance and Heat Dissipation : Thermal Resistance in Conduction
- Fundamentals of Thermal Resistance and Heat Dissipation : Thermal Resistance in Convection
- Fundamentals of Thermal Resistance and Heat Dissipation : Thermal Resistance in Emission
- Thermal Resistance Data: JEDEC Standards, Thermal Resistance Measurement Environments, and Circuit Boards
- Thermal Resistance Data: Actual Data Example
- Thermal Resistance Data: Definitions of Thermal Resistance, Thermal Characterization Parameters
- Thermal Resistance Data: θJA and ΨJT in Estimation of TJ: Part 1
- Thermal Resistance Data: θJA and ΨJT in Estimation of TJ: Part 2
- Surface Temperature Measurements: Methods for Fastening Thermocouples
- Surface Temperature Measurements: Thermocouple Mounting Position
- Surface Temperature Measurements: Treatment of Thermocouple Tips
- Surface Temperature Measurements: Influence of the Thermocouple
- Estimating TJ: Basic Calculation Equations
- Estimating TJ: Calculation Example Using θJA
- Estimating TJ: Calculation Example Using ΨJT
- Estimating TJ: Calculation Example Using Transient Thermal Resistance
- Estimation of Heat Dissipation Area in Surface Mounting and Points to be Noted
- Surface Temperature Measurements: Thermocouple Types
- Summary
- Collection of Important Points Relating to Thermal Design
Switching Noise
- Procedures in Noise Countermeasures
- What is EMC?
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Dealing with Noise Using Capacitors
- Understanding the Frequency Characteristics of Capacitors, Relative to ESR and ESL
- Measures to Address Noise Using Capacitors
- Effective Use of Decoupling (Bypass) Capacitors Point 1
- Effective Use of Decoupling Capacitors Point 2
- Effective Use of Decoupling Capacitors, Other Matters to be Noted
- Effective Use of Decoupling Capacitors, Summary
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Dealing with Noise Using Inductors
- Frequency-Impedance Characteristics of Inductors and Determination of Inductor’s Resonance Frequency
- Basic Characteristics of Ferrite Beads and Inductors and Noise Countermeasures Using Them
- Dealing with Noise Using Common Mode Filters
- Points to be Noted: Crosstalk and Noise from GND Lines
- Summary of Dealing with Noise Using Inductors
- Other Noise Countermeasures
- Basics of EMC – Summary
Simulation
- Thermal Simulation of PTC Heaters
- Thermal Simulation of Linear Regulators
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Foundations of Electronic Circuit Simulation Introduction
- About SPICE
- SPICE Simulators and SPICE Models
- Types of SPICE simulation: DC Analysis, AC Analysis, Transient Analysis
- Types of SPICE simulation: Monte Carlo
- Convergence Properties and Stability of SPICE Simulations
- Types of SPICE Model
- SPICE Device Models: Diode Example–Part 1
- SPICE Device Models: Diode Example–Part 2
- SPICE Subcircuit Models: MOSFET Example―Part 1
- SPICE Subcircuit Models: MOSFET Example―Part 2
- SPICE Subcircuit Models: Models Using Mathematical Expressions
- About Thermal Models
- About Thermal Dynamic Model
- Summary
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About the ROHM Solution Simulator
- How to Access the ROHM Solution Simulator
- Trying Out the ROHM Solution Simulator (1)
- Trying Out the ROHM Solution Simulator (2)
- Starting a Simulation Circuit in the ROHM Solution Simulator
- ROHM Solution Simulator Toolbar Functions and Basic Operations
- ROHM Solution Simulator: User Interface
- Execution of Simulations
- Method for Displaying Simulation Results
- Simulation Result Display Tool: Wavebox
- Simulation Results Display Tool: Waveform Viewer
- Customization of Simulations
- Exporting Circuit Data to PartQuest™ Explorer
- Purchasing Samples for Evaluation
- Optimization of PFC Circuits
- Optimization of Inverter Circuits
- About Thermal Simulations of DC-DC Converters
- Circuit-Theory-Based Design Simulation