Bent Heat Radiation Member PCB Noise Current Propagation

Solution Overview

Problem

Existing printed circuit boards face issues with electromagnetic wave radiation due to noise currents generated by high heat-generating electronic elements, which can cause malfunctions in peripheral circuits and devices, particularly because the flat heat radiation boards act as antennas, leading to inefficient propagation of noise currents to the substrate.

Innovation Solution

A printed circuit board design where the heat radiation member's end portion is positioned closer to the printed wiring board than its connection point with the electronic element, with a space between, allowing for shorter noise current propagation paths and enhanced capacitive coupling, thereby reducing electromagnetic wave radiation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If the heat radiation board is connected to the signal ground through a conductive stud, then the noise current is propagated to the printed substrate, but the electromagnetic wave is still radiated widely from the end portion of the heat radiation board

Engineering Contradiction:

Improveelectromagnetic wave radiationVSAvoidnoise current propagation efficiency

Core Design Contradiction:

Object-generated harmful factorsVSReliability

Solution Approach 1:

The heat radiation board is transformed from a flat two-dimensional structure to a three-dimensional structure by bending the end portion toward the printed substrate. This dimensional change reduces the distance between the end portion and the substrate, improving noise current propagation while maintaining electromagnetic wave prevention.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The end portion of the heat radiation board is bent into a curved shape toward the printed substrate. This curvature allows the end portion to approach the substrate more closely, enhancing the propagation path for noise currents while preventing electromagnetic wave radiation to the periphery.

Inventive Principle:

Principle #14Spheroidality (Curvature)

2Device complexity

If the heat radiation board is in a flat board shape, then the structure is simple, but the noise current is more likely to be radiated on the periphery as an electromagnetic wave

Engineering Contradiction:

Improveheat radiation board structureVSAvoidelectromagnetic wave radiation

Core Design Contradiction:

Device complexityVSObject-generated harmful factors

Solution Approach 1:

The end portion of the heat radiation board is bent into a curved shape toward the printed substrate. This curvature allows the end portion to approach the substrate more closely, enhancing the propagation path for noise currents while preventing electromagnetic wave radiation to the periphery.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The heat radiation board is transformed from a flat two-dimensional structure to a three-dimensional structure by bending the end portion toward the printed substrate. This dimensional change reduces the distance between the end portion and the substrate, improving noise current propagation while maintaining electromagnetic wave prevention.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Reliability

If the end portion of the heat radiation member is positioned closer to the printed wiring board, then the noise current propagation path is shortened, but a space must be maintained between them

Engineering Contradiction:

Improvenoise current propagation efficiencyVSAvoiddistance between end portion and printed wiring board

Core Design Contradiction:

ReliabilityVSLength of stationary object

Solution Approach 1:

The heat radiation board is transformed from a flat two-dimensional structure to a three-dimensional structure by bending the end portion toward the printed substrate. This dimensional change reduces the distance between the end portion and the substrate, improving noise current propagation while maintaining electromagnetic wave prevention.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The end portion of the heat radiation board is bent into a curved shape toward the printed substrate. This curvature allows the end portion to approach the substrate more closely, enhancing the propagation path for noise currents while preventing electromagnetic wave radiation to the periphery.

Inventive Principle:

Principle #14Spheroidality (Curvature)

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 configuration effectively prevents electromagnetic wave radiation from the printed circuit board, minimizing interference with peripheral electronic devices by efficiently propagating noise currents to the printed wiring board's ground layer, enhancing cooling efficiency through a sheet-shaped heat transfer member.

Implementation Method 1

a heat radiation member provided on an opposite side of a side on which the printed wiring board is positioned with respect to the electronic element, the heat radiation member thermally connected to the electronic element

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

allowing for shorter noise current propagation paths and enhanced capacitive coupling, thereby reducing electromagnetic wave radiation

Methodology Applied

Scientific EffectCapacitive coupling: Capacitance

Data Source

PatentUS11013102B2Printed circuit board and electronic device

Publication Date: 2021.05.18 SEIKO EPSON CORP

AI summary

A printed circuit board includes a printed wiring board, an electronic element provided on a mounting surface of the printed wiring board, and a heat radiation member provided on an opposite side of a side on which the printed wiring board is positioned with respect to the electronic element, the heat radiation member thermally connected to the electronic element. An end portion of the heat radiation member is disposed closer to the printed wiring board than a connection portion with the electronic element in the heat radiation member, in a state where a space is provided between the end portion and the printed wiring board.