PCB Thermal Management via Elastic Clips and Insulating Vias

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Solution Overview

Problem

Current power electronic solutions face challenges in heat dissipation, reliability, and cost-effectiveness, particularly in high-power applications, where manual assembly and thermal management are costly and inefficient, leading to issues with temperature control and module repairability.

Innovation Solution

A printed circuit board unit with surface-mountable components and metallic vias for heat conduction, using a thermally conductive and electrically insulating layer between power elements and heat sinks, pressed by elastic clips for efficient heat dissipation via air or liquid cooling, allowing for modular design and easy maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a massive base plate is used for heat dissipation, then heat dissipation capability is improved, but repairability deteriorates because soldering temperature cannot be reached without damaging the circuit

Engineering Contradiction:
Improveheat dissipation capabilityVSAvoidrepairability
Core Design Contradiction:
TemperatureVSEase of repair

Solution Approach 1:

The cooling device is divided into multiple independent cooling elements (first cooling element and second cooling element) that can be separately applied to different regions of the circuit board. This segmentation allows the cooling function to be maintained while enabling localized repair work without the entire massive base plate interfering with soldering temperatures.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of using a uniform massive base plate throughout, the patent applies cooling elements selectively to specific high-heat-generation areas (such as near power elements). This localised approach provides sufficient heat dissipation where needed while leaving other areas accessible for repair work.

Inventive Principle:
Principle #3Local quality

2Temperature

If thin insulation layers with increased thermal conductivity are used, then heat dissipation is improved, but electrical stray capacitances increase which is unfavorable for higher voltages and frequencies

Engineering Contradiction:
Improveheat dissipationVSAvoidelectrical stray capacitances
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a thermally conductive but electrically insulating intermediate layer between the cooling element and the circuit board. This intermediary layer acts as a thermal bridge while maintaining electrical isolation, thereby reducing stray capacitances compared to direct metal-to-metal contact, while still providing effective heat dissipation.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If manual assembly processes are used for power semiconductors and cooling devices, then assembly quality can be controlled, but manufacturing costs and time increase significantly

Engineering Contradiction:
Improveassembly qualityVSAvoidmanufacturing efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The cooling elements are designed to be pre-positioned or pre-assembled in specific locations on the circuit board before final component assembly. This preliminary arrangement ensures proper thermal management is established early, maintaining quality control while streamlining the overall manufacturing process.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The cooling elements are designed with features that enable automatic or self-alignment during assembly, reducing the need for complex manual positioning and adjustment. This allows standard automated SMT equipment to be used while maintaining assembly quality.

Inventive Principle:
Principle #25Self-service

4Ease of manufacture

If power elements are cooled only at the edges of the circuit board, then manufacturing is simplified, but heat dissipation toward the center deteriorates due to limited lateral heat conduction

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidheat dissipation toward center
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The patent transitions from edge-only cooling (one-dimensional heat dissipation path) to multi-point cooling distributed across the circuit board surface. By placing cooling elements at multiple locations including central regions, heat dissipation occurs in multiple directions and dimensions, effectively cooling central power elements without complicating manufacturing.

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

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 effective heat dissipation, enhances reliability, and reduces manufacturing costs, allowing for the use of the same modules in both high-price and low-price products, and supports efficient operation in harsh environmental conditions.

Implementation Method 1

metallic vias for heat conduction, wherein between the heat-conducting areas and one or more heat sinks a thermally conductive and electrically insulating layer is arranged

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

a thermally conductive and electrically insulating layer, which is arranged between the surface-mountable power elements and one or more heat sinks

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

the surface-mountable power elements are pressed with at least one elastic clip via the intermediate printed circuit board against the one or more heat sinks

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 4

heat dissipation via air or liquid cooling

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 5

one or more heat sinks in the area of the vias and the surface-mountable power elements are pressed

Methodology Applied
Scientific EffectHeat sink: Heat Sink

Data Source

PatentEP2114113B1Printed Circuit Board and corresponding production method
Publication Date: 2014.05.28 AGIE CHARMILLES SA
  • EP2114113B1 patent drawingFigure 1~2
  • EP2114113B1 patent drawingFigure 3~5
  • EP2114113B1 patent drawingFigure 6~7

AI summary

The method involves arranging thermally loaded surface-mountable conductive elements (1) e.g. surface mount device, in heat conducting regions on a printed circuit board (2). A thermally conductive and electrically isolative layer (3) is arranged between the conductive elements and cooling bodies (4) in a region of through-contacts. The conductive elements with an elastic clip (5) are pressed against the cooling bodies above the circuit board such that heat produced by the conductive elements is dissipated to the cooling bodies by the through-contacts. The thermally conductive and electrically isolative layer is made of ceramic. An independent claim is also included for a printed circuit board unit comprising a printed circuit board.