Planar Transformer Thermal Management via Layered PCB
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Planar transformers for power transmission face challenges in heat dissipation and miniaturization, particularly when supplying multiple galvanically isolated circuits, leading to increased heat production and complexity in cooling, which hinders the miniaturization of electrical components and may result in temperature exceedance risks.
Innovation Solution
A planar transformer design with a sandwich-type circuit board structure featuring at least three layers, where insulation material is used between layers, and a magnetic core with U-shaped components inserted into recesses in the circuit board, allowing for efficient heat dissipation and reduced layer count, enabling integration into isolation amplifiers without additional cooling bodies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the transformer is miniaturized to reduce component size, then the volume and area are reduced, but the heat dissipation capability deteriorates and temperature increases
Solution Approach 1:
The patent transitions from traditional three-dimensional wound coil transformers to a planar two-dimensional structure fabricated on circuit boards. This dimensional change allows for larger surface area relative to volume, improving heat dissipation while maintaining compact size. The planar windings distributed across multiple layers provide enhanced thermal pathways to the board surface for convection cooling.
Solution Approach 2:
The patent utilizes the circuit board structure with multiple layers and ventilation openings that create porous-like thermal pathways. The insulation layers between copper traces and the board structure itself provide thermal conduction paths while maintaining electrical isolation, enabling efficient heat transfer from internal windings to the external environment.
2Volume of moving object
If the transformer is miniaturized to reduce component size, then the volume is reduced, but the heat dissipation area is reduced leading to increased heat production
Solution Approach 1:
By spreading the windings across multiple planar layers rather than concentrating them in a three-dimensional coil, the patent increases the effective heat dissipation surface area. The top and bottom surfaces of the circuit board both contribute to thermal dissipation, effectively doubling the available cooling surface compared to traditional vertical coil structures.
Solution Approach 2:
The circuit board serves multiple functions simultaneously: it provides electrical insulation between windings, mechanical support for the planar traces, thermal conduction pathways to dissipate heat, and structural integration with the housing. This multi-functionality eliminates the need for separate cooling components.
3Temperature
If additional cooling bodies are added to improve heat dissipation, then the heat dissipation capability is improved, but the device complexity increases
Solution Approach 1:
The patent merges the cooling function directly into the circuit board structure itself. The board's layered construction with ventilation openings and thermal pathways integrates heat dissipation capabilities without requiring separate cooling components. The housing may also serve as a thermal management element, eliminating the need for additional cooling bodies.
Solution Approach 2:
The circuit board structure provides its own heat dissipation capabilities through its inherent thermal conduction pathways and convection surfaces. The design relies on natural convection and radiation from the board surfaces rather than requiring active cooling systems or additional passive cooling components, making the system self-sufficient for thermal management.
4Device complexity
If the number of layers is reduced to simplify manufacturing, then the manufacturing complexity is reduced, but the insulation capability may be compromised
Solution Approach 1:
The patent applies different insulation strategies to different regions of the circuit board. Critical high-voltage isolation areas use thicker insulation layers or additional protective coatings, while lower-voltage regions use standard trace spacing. This localized approach to insulation quality maintains reliability where needed while minimizing overall layer count and manufacturing complexity.
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 and miniaturization, allowing for the use of planar transformers in isolation amplifiers with improved insulation and reduced layer count, thus addressing heat management and miniaturization challenges while maintaining high insulation standards.
Implementation Method 1
a magnetic core (5) including at least partially the sandwich type structure and acting at least on the first, second and third circuits
Data Source
AI summary
A planar transformer for power transmission, having vertical and horizontal extents, includes a circuit board having a sandwich-type structure with at least three layers to form electrical conductors. First and second layers of these layers form outer layers of the circuit board, and each additional one of these layers forms an inner layer of the circuit board. An insulation material with a minimum thickness is arranged between all of these layers, with a number of at least three mutually galvanically isolated circuits. A first circuit forms a primary circuit and each additional circuit forms an equally entitled secondary circuit, having a magnetic core assembled from two interconnected magnetic core parts. A first core part with a central part and two outer legs forms a U shape. The circuit board has two recesses, and the two outer legs of the first core part are inserted into these recesses and connected to the second core part at their ends remote from the central part. A conductor is formed on at least one of the outer layers for exactly one single circuit of the at least three circuits, and a conductor of at least one circuit of the at least three circuits is wound around a first outer leg, and conductors of at least two additional circuits of the at least three circuits are wound around the second outer leg.