PV Optimizer Package Layout for Thermal Path and EMI Shielding

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Solution Overview

Problem

Existing package structures for photovoltaic optimizers face challenges with heat dissipation and electromagnetic shielding, leading to potential overheating and reliability issues due to high switching frequencies and large current flows in MOS transistors.

Innovation Solution

The proposed solution involves a photovoltaic optimizer with a package structure that includes a first housing with a heat dissipation protrusion or fin, and a package module with a substrate configuration that facilitates heat transfer and electromagnetic shielding. The heat dissipation protrusion or fin increases the heat dissipation area, while the substrate configuration ensures efficient heat transfer and electromagnetic shielding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the MOS transistor is frequently turned on and turned off to achieve high switching frequency, then the power conversion efficiency is improved, but a magnetic field that changes at a high frequency is generated which induces high-order harmonic components in the circuit

Engineering Contradiction:
Improvepower conversion efficiencyVSAvoidhigh-order harmonic components
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

An electromagnetic shielding layer is introduced as an intermediary between the MOS transistor and the surrounding circuit environment. This shielding layer blocks the magnetic field generated by the MOS transistor during switching operations, preventing the induction of high-order harmonic components in adjacent circuits while allowing the high switching frequency operation to continue for maintaining power conversion efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The harmful magnetic field effect is extracted and isolated from the main circuit by using the electromagnetic shielding layer. The shielding layer captures and contains the magnetic field within a specific region, separating it from other circuit components that would otherwise be affected by the high-order harmonic components.

Inventive Principle:
Principle #2Taking out (Extraction)

2Productivity

If the MOS transistor frequently switches to improve power conversion, then switching loss and conduction loss are generated which release heat energy, but if the heat energy cannot be transferred out in time, the MOS transistor is exposed to burning out risk

Engineering Contradiction:
Improvepower conversion efficiencyVSAvoidMOS transistor reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The heat energy that would otherwise be harmful and cause transistor failure is converted into a beneficial situation by providing an efficient heat dissipation path. The electromagnetic shielding layer serves dual functions: it shields magnetic fields and simultaneously acts as a heat conduction path, converting the harmful heat accumulation into a controlled heat transfer process that maintains transistor reliability during high-frequency switching operations.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The electromagnetic shielding layer is designed to perform multiple functions simultaneously: it provides electromagnetic shielding to block magnetic fields, serves as a heat dissipation path to conduct heat away from the MOS transistor, and contributes to the overall structural integrity of the package. This multi-functionality allows the system to maintain both high switching frequency operation and reliable transistor performance.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Device complexity

If the package structure is simplified to reduce module size and costs, then manufacturing complexity is reduced, but heat dissipation and electromagnetic shielding functions may be compromised

Engineering Contradiction:
Improvepackage structure complexityVSAvoidheat dissipation and electromagnetic shielding performance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The electromagnetic shielding layer is designed to perform multiple functions simultaneously: it provides electromagnetic shielding to block magnetic fields, serves as a heat dissipation path to conduct heat away from the MOS transistor, and contributes to the overall structural integrity of the package. This multi-functionality allows the system to maintain both high switching frequency operation and reliable transistor performance.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The electromagnetic shielding function and heat dissipation function are merged into a single integrated structure - the electromagnetic shielding layer. Instead of having separate components for shielding and heat dissipation, the design combines these functions into one element, simplifying the overall package structure while maintaining both shielding performance and heat dissipation capability.

Inventive Principle:
Principle #5Merging (Combining)

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 effectively improves heat dissipation and electromagnetic shielding, reducing the risk of overheating and enhancing the overall reliability of the photovoltaic optimizer. It simplifies the structure, reduces module size and costs, and enhances heat dissipation efficiency.

Implementation Method 1

The outer wall of a side that is of the bottom plate and that faces away from the cover plate is provided with a heat dissipation protrusion or a heat dissipation fin extending outward... the heat dissipation protrusion or the heat dissipation fin can increase a heat dissipation area of the bottom plate

Methodology Applied
Scientific EffectHeat dissipation: Convection

Implementation Method 2

heat generated by the power device may be transferred to the first substrate via the second substrate, and the heat transferred to the first substrate may be dissipated to the outside as soon as possible via a heat dissipation path sequentially passing through the metal substrate, the bottom plate, and the heat dissipation protrusion or the heat dissipation fin

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 3

a surface of a side that is of the second metal layer and that faces away from the insulation substrate is connected to a surface of a side that is of the first metal layer and that faces away from the insulation layer, so that the second metal layer and the first metal layer may be combined with each other to serve as an electromagnetic shield layer

Methodology Applied
Scientific EffectElectromagnetic shielding: Faraday Cage

Data Source

PatentEP4525034A1Photovoltaic optimizer and package structure
Publication Date: 2025.03.19 HUAWEI DIGITAL POWER TECH CO LTD
  • EP4525034A1 patent drawingFigure 1~2
  • EP4525034A1 patent drawingFigure 3a~3b
  • EP4525034A1 patent drawingFigure 4a~5a

AI summary

This application discloses a photovoltaic optimizer and a package structure. The photovoltaic optimizer includes a first housing and the package structure accommodated in the first housing. The package structure includes a first substrate, a package module, a circuit board, and a conductor. The first substrate includes a first metal layer, an insulation layer, and a metal substrate. The package module includes a second substrate, a power device, and a first pin. The second substrate includes a second metal layer, an insulation substrate, and a third metal layer. Based on this, heat generated by the power device is transferred to the first substrate via the second substrate, and then is transferred to a bottom plate via the first substrate. The heat is dissipated to the outside via the bottom plate, a heat dissipation protrusion, or a heat dissipation fin. In addition, the conductor connects the second metal layer to a ground potential pad on the circuit board, and a surface of a side that is of the second metal layer and that faces away from the insulation substrate is connected to a surface of a side that is of the first metal layer and that faces away from the insulation layer, so that the second metal layer and the first metal layer are combined with each other to serve as an electromagnetic shield layer. This implements electromagnetic shielding.