Photovoltaic Junction Box Thermal Management via Segmented Terminals
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Solution Overview
Problem
The existing photovoltaic junction boxes have a limited heat conduction angle, which reduces the efficiency of heat dissipation from diodes to conduction terminals, leading to potential overheating and reduced current-carrying capacity.
Innovation Solution
The design incorporates surface-mounted diodes with a heat conduction angle greater than 180 degrees by using notches and projections on the conduction terminals, allowing for improved heat transfer and dissipation, and varying surface areas and angles to optimize thermal conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If diodes are soldered on conduction terminals with parallel edges, then the manufacturing process is simple, but the heat conduction angle is limited to 180 degrees or less, reducing heat dissipation efficiency
Solution Approach 1:
The conduction terminal edge is segmented into multiple surfaces by introducing notches, transforming a single-plane soldering surface into multi-plane surfaces. This segmentation allows the diode cathode pad to contact multiple surfaces simultaneously, increasing the heat conduction angle from 180 degrees or less to more than 180 degrees, thereby improving heat dissipation efficiency.
Solution Approach 2:
The notches are designed with asymmetric geometry, where the first lateral edge and second lateral edge form different angles (α and β) with the bottom edge. This asymmetric design optimizes the heat conduction angle γ = 540° - α - β to be greater than 180°, enhancing thermal contact between the cathode pad and conduction terminal while maintaining manufacturing feasibility.
2Productivity
If diodes are mounted with heat conduction angle greater than 180 degrees using notches, then heat dissipation rate improves, but manufacturing complexity increases
Solution Approach 1:
The design changes the geometric parameters of the conduction terminal by introducing notches with specific angle parameters (α and β) to achieve a heat conduction angle γ > 180°. This parameter change optimizes thermal contact area while the notches can be fabricated using standard PCB processing techniques, balancing manufacturing complexity with thermal performance.
3Reliability
If cathode pad is positioned to maximize heat conduction angle, then thermal conductivity improves, but positioning precision requirements increase
Solution Approach 1:
The notches transform the soldering interface from a two-dimensional planar contact to a three-dimensional multi-surface contact. By creating lateral edges that extend in multiple directions, the design increases the heat conduction angle and thermal contact area, providing tolerance compensation that reduces sensitivity to positioning precision requirements.
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 design enhances heat dissipation rates and current-carrying capacity, improving the stability and performance of the photovoltaic junction box.
Implementation Method 1
the heat produced by the diode may be rapidly transferred to the conduction terminal in time, improving the heat dissipation rate
Data Source
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AI summary
The present disclosure discloses a photovoltaic junction box, including: a box body; a plurality of conduction terminals received in the box body; and at least one surface-mounted diode mounted on the plurality of conduction terminals by means of Surface Mount Technology. Each surface-mounted diode includes a flat body, at least one anode pin extending outwardly from an edge of the flat body, and a cathode pad located on a bottom of the flat body. The cathode pad of at least one surface-mounted diode mounted on a surface of the conduction terminal has a heat conduction angle γ more than 180 degrees and less than 360 degrees. Since the heat conduction angle is more than 180 degrees, the heat produced by the diode may be rapidly transferred to the conduction terminal in time, improving the heat dissipation rate, and improving the current carrying capacity of the photovoltaic junction box.