PCB Cooling Structure for Surface-Mounted Photoelectric Conversion Element

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Solution Overview

Problem

High-resolution, high-speed, and miniaturized imaging elements with multiple terminals on their back surface pose challenges for effective cooling, as conventional cooling methods like heat sinks cannot directly contact the back surface due to terminal placement, leading to insufficient heat dissipation and increased noise susceptibility.

Innovation Solution

A cooling mechanism involving front-surface and back-surface copper foil patterns connected via through-holes, with a cooling member in contact with the back-surface pattern, effectively transfers heat from the imaging element through the fixation terminal, reducing thermal resistance and enhancing cooling efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the imaging element is mounted on the front surface of the printed circuit board with multiple terminals on the back surface, then high resolution and miniaturization are achieved, but the area available for cooling means contact is insufficient

Engineering Contradiction:
Improveimaging element sizeVSAvoidcooling contact area
Core Design Contradiction:
Volume of moving objectVSArea of stationary object

Solution Approach 1:

The invention transitions from two-dimensional surface cooling to three-dimensional internal cooling by routing heat dissipation paths through the thickness of the printed circuit board. Through-holes and internal wiring channels enable thermal conduction in the Z-direction (thickness direction), allowing cooling contact at the back surface while maintaining front-surface mounting configuration.

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

Solution Approach 2:

The invention introduces intermediary structures including through-hole conductive paths, internal wiring, and thermal interface materials that mediate heat transfer between the imaging element and cooling means. These intermediaries enable thermal coupling without requiring direct surface contact, resolving the spatial conflict between terminals and cooling contact areas.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If belt-shaped heat transfer sheet is used for heat dissipation, then heat transfer is enabled, but thermal conductivity is lower than metal materials resulting in insufficient heat dissipation

Engineering Contradiction:
Improveheat dissipation implementationVSAvoidheat dissipation efficiency
Core Design Contradiction:
Ease of manufactureVSLoss of energy

Solution Approach 1:

The invention employs composite thermal management structures combining metal heat dissipation members with thermally conductive materials. The printed circuit board integrates copper or aluminum heat dissipation members with thermally conductive resin, creating a composite structure that achieves high thermal conductivity while maintaining manufacturing ease and structural integrity.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention changes the thermal conductivity parameter by replacing low-conductivity belt-shaped heat transfer sheets with high-conductivity metal heat dissipation members and thermally conductive composite materials. This parameter change significantly improves heat dissipation efficiency while maintaining ease of manufacture through standardized PCB fabrication processes.

Inventive Principle:
Principle #35Parameter changes

3Loss of energy

If copper foil pattern of power supply terminals is exposed for heat dissipation, then heat transfer is achieved, but the terminals are susceptible to disturbance noise causing short-circuit

Engineering Contradiction:
Improveheat dissipation capabilityVSAvoidterminal electrical stability
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The invention segments the terminal functions by separating heat dissipation pathways from electrical signal pathways. Through-holes and internal wiring layers are dedicated to thermal conduction, while surface terminals maintain electrical connectivity. This functional segmentation eliminates noise susceptibility while preserving heat dissipation capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces intermediary conductive paths through the PCB substrate that mediate between the terminals and heat dissipation structures. These internal wiring channels and through-hole vias act as thermal intermediaries, conducting heat away from terminals without exposing the electrical terminals themselves to thermal stress or electrical interference.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Temperature

If through-holes are formed in the printed circuit board for cooling, then direct cooling contact is achieved, but the structural integrity and electrical connectivity may be compromised

Engineering Contradiction:
Improvecooling effectivenessVSAvoidprinted circuit board integrity
Core Design Contradiction:
TemperatureVSStrength

Solution Approach 1:

The invention uses composite material structures where through-holes are reinforced with conductive plating and filled with thermally conductive materials. The printed circuit board combines rigid substrate materials with metal reinforcement layers, maintaining structural integrity while enabling effective thermal conduction paths through the board thickness.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention applies local quality enhancement by concentrating thermal management features in specific regions rather than throughout the entire board. Through-holes and heat dissipation structures are strategically positioned near heat-generating components, while other regions maintain full structural integrity. This localized approach minimizes overall structural compromise.

Inventive Principle:
Principle #3Local quality

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 allows for effective cooling of the imaging element with reduced thermal resistance and improved signal-to-noise ratios by providing a direct heat dissipation path, while avoiding noise interference from exposed power supply terminals.

Implementation Method 1

heat transfer sheet is employed, one side of the belt-shaped heat transfer sheet is in contact with the copper pattern of the printed circuit board, the other end of the belt-shaped heat transfer sheet is in contact with a metal frame, and thereby in this stage unit to which the imaging element is mounted, the heat dissipation is performed

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

a cooling means, which is a heat sink, for example, and which is located at a back surface side of the printed circuit board, come into direct contact with the back surface of the imaging element

Methodology Applied
Scientific EffectHeat sink: Heat Sink

Data Source

PatentEP3118899B1Cooling structure for photoelectric conversion element
Publication Date: 2018.10.10 OLYMPUS CORPORATION(JP)
  • EP3118899B1 patent drawingFigure 1
  • EP3118899B1 patent drawingFigure 2
  • EP3118899B1 patent drawingFigure 3~4

AI summary

This cooling mechanism for a surface-mounted-type photoelectric conversion element is provided on a circuit board (109) to which a surface-mounted-type photoelectric conversion element (100), which has a signal terminal that is connected to inner wiring and a terminal for fixation that is not connected to the inner wiring on a back surface thereof, is mounted, the cooling mechanism has a front-surface-side copper foil pattern (104) to which the terminal for fixation is connected, a back-surface-side copper foil pattern (107), and a through-hole via (10) which connects the copper foil patterns, a cooling member (108) which is fixed to the circuit board so as to have contact with the back-surface-side copper foil pattern, and which cools the back-surface-side copper foil pattern.