Multi-Point Thermal Path Assessment for Integrated Circuits

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Solution Overview

Problem

As power demand in integrated circuits increases, accurate verification of thermal paths and system-level thermal performance of printed circuit board assemblies (PCBAs) becomes challenging due to inadequate solder connections and limitations in existing inspection methods like X-ray screening, which can lead to faulty connections and reduced reliability.

Innovation Solution

A method and system for multi-point thermal path assessment of integrated circuits, utilizing temperature sensing devices and a controller to apply heat in different modes, measure temperature changes, and determine the sufficiency of thermal paths by comparing delta temperatures to predetermined ranges, allowing for precise characterization and repair of thermal interfaces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If X-ray screening processes are used to verify thermal paths, then inspection coverage is improved, but measurement precision deteriorates due to inability to accurately detect thermal performance

Engineering Contradiction:
Improvethermal path verification accuracyVSAvoidthermal performance detection difficulty
Core Design Contradiction:
Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent replaces non-contact X-ray screening with direct thermal measurement using temperature sensing devices that physically contact or closely proximity the IC. This substitution enables actual thermal performance measurement rather than indirect imaging, resolving the contradiction between inspection coverage and measurement precision for thermal paths.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces temperature sensing devices as intermediaries between the heat source (IC) and the measurement system. These sensors directly measure thermal conditions at critical points, providing accurate thermal path verification that bridges the gap between visual inspection and actual thermal performance assessment.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Power

If power demand in ICs is increased to meet application requirements, then performance is improved, but thermal path sufficiency deteriorates leading to overheating risks

Engineering Contradiction:
ImproveIC power demandVSAvoidthermal path reliability
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The patent performs preliminary thermal path assessment during manufacturing by measuring temperature changes in ICs under controlled heat application. This early detection identifies insufficient thermal paths before the ICs are deployed in high-power applications, preventing future overheating and reliability issues while enabling higher power operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements a feedback mechanism where temperature measurements from multiple sensing devices are used to evaluate thermal path sufficiency. The system compares measured temperature changes against expected values and provides feedback on thermal path quality, enabling corrective actions before high-power operation to ensure reliability.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If multiple temperature sensing devices are deployed for comprehensive thermal assessment, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvethermal path assessment accuracyVSAvoidassessment system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent divides the thermal assessment function into multiple independent temperature sensing devices placed at different locations on the IC. Each sensor independently measures thermal conditions at its location, and the results are combined to provide comprehensive thermal path assessment. This segmentation improves measurement precision across the entire IC while keeping individual sensor complexity low.

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 approach enables accurate and reliable assessment of thermal paths, ensuring sufficient thermal performance and reducing the likelihood of IC overheating or failure by identifying and correcting insufficient solder connections and thermal interfaces during manufacturing.

Implementation Method 1

The controller is configured to supply power to the integrated circuit according to a selected heat application mode

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

a first temperature of the integrated circuit using one or more thermal sensing devices

Methodology Applied
Scientific EffectThermal sensing: Thermography

Data Source

PatentEP3712591B1System and method for multi-point thermal path assessment
Publication Date: 2024.10.23 BORGWARNER US TECHNOLOGIES LLC
  • EP3712591B1 patent drawingFigure 1A~1B
  • EP3712591B1 patent drawingFigure 2A
  • EP3712591B1 patent drawingFigure 2B

AI summary

A method (700) for assessing a thermal path associated with an integrated circuit (102, 202, 302, 402) includes identifying a heat application mode based on a design type of the integrated circuit (102, 202, 302, 402). The method (700) also includes measuring (706) a first temperature of at least one thermal sensing device (106, 206, 306, 406) associated with the integrated circuit (102, 202, 302, 402). The method (700) also includes applying heat (708) to at least a portion of the integrated circuit (102, 202, 302, 402) according to the heat application mode. The method (700) also includes measuring a second temperature (710) of the at least one thermal sensing device (106, 206, 306, 406). The method (700) also includes determining (712) a difference between the first temperature and the second temperature. The method (700) also includes determining (712) whether a thermal path between the integrated circuit (102, 202, 302, 402) and an associated substrate is sufficient based on a comparison (714) of the difference between the first temperature and the second temperature with a predetermined difference between an initial temperature and a subsequent temperature of the at least one thermal sensing device (106, 206, 306, 406).