Magnetic PCB Ferrite Coating for Low-Temperature GHz Operation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional ferrite film deposition technologies for magnetic PCBs require high temperatures, damaging polymer-based PCBs and resulting in low relative permeability and high magnetic loss tangents, making them unsuitable for high-frequency applications.
Innovation Solution
Spin spray deposition of ferrite films at lower temperatures, using aqueous solutions with metals and oxidizers, to create highly anisotropic structures with high relative permeability and low loss tangents, enabling the production of magnetic PCBs suitable for high-frequency operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional ferrite film deposition technologies (pulsed laser deposition, sputtering, molecular beam epitaxy) are used, then high crystalline quality ferrite materials can be formed, but high temperatures (>700°C) are required which damage polymer-based PCBs
Solution Approach 1:
The patent changes the temperature parameter from conventional high temperatures (>700°C) to low temperatures (<200°C) by using a novel chemical vapor deposition process. This parameter change enables the formation of high-quality ferrite films without damaging the polymer PCB substrate, resolving the contradiction between achieving high crystalline quality and avoiding substrate damage.
Solution Approach 2:
The patent replaces physical vapor deposition methods (sputtering, molecular beam epitaxy) with a chemical vapor deposition approach using organic metal salts as precursors. This substitution allows ferrite film formation at lower temperatures through chemical reactions rather than physical processes, enabling compatibility with polymer-based PCBs while maintaining film quality.
2Ease of manufacture
If ferrite powders are integrated inside PCBs, then magnetic PCBs can be manufactured, but large magnetic loss tangents and low relative permeability values (1-3) result
Solution Approach 1:
The patent creates a composite structure with ferrite films deposited directly on the PCB surface, forming a magnetodielectric composite material. This composite approach combines the advantages of ferrite (high permeability, low loss) with the PCB substrate, achieving both ease of manufacture and low magnetic loss tangents while maintaining high relative permeability values.
Solution Approach 2:
The patent utilizes the porous or layered structure of the deposited ferrite films to optimize magnetic properties. The film structure allows for controlled permeability and loss characteristics, achieving low magnetic loss tangents while maintaining manufacturability through the deposition process.
3Volume of moving object
If ferrite films are deposited to miniaturize antennas using moderate permittivity and permeability values, then antenna size is reduced, but operating frequency and gain are limited
Solution Approach 1:
The patent changes the magnetic permeability parameter by depositing ferrite films with controlled composition and thickness, achieving high relative permeability values (μr > 100). This parameter change enables the antenna to operate at higher frequencies with reduced size, as the enhanced magnetic properties allow for smaller electrical dimensions while maintaining resonant frequency 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
The spin spray method allows for the production of magnetic PCBs with high permeability and low loss tangents, suitable for frequencies up to several GHz, while being cost-effective and compatible with organic substrates, achieving compact, efficient antennas and inductors with improved gain and bandwidth.
Implementation Method 1
The inventors of this patent application developed a novel spin spray technology to deposit ferrite films on PCBs for manufacturing magnetic PCBs
Implementation Method 2
Metals reactant solution and oxidizer solution are respectively provided to substrate via nozzles while the substrate is rotated
Implementation Method 3
the deposited ferrite films on PCBs have the potential of operating from DC to several GHz with high relative permeability of over 100 and low loss tangents
Implementation Method 4
Because spin spray deposition produces thin film geometry with dense nanocrystalline ferrite crystal sizes and large shape anisotropy
Data Source
AI summary
A magnetic PCB generated by simultaneously spin-spraying a ferrite ion solution and an oxidant solution on a substrate plate while the substrate plate is rotated at a speed 40 rpm to about 300 rpm and heated at 40° C. to 300° C.