Ultrasound Flow Meter EMI Shielding via Multi-Layer PCB
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing ultrasound flow meters are susceptible to electromagnetic interference (EMI) from external fields, which degrades data quality by influencing signals between the ultrasound transducers and electronic circuits.
Innovation Solution
A multi-layer circuit board design with electrically conducting layers that act as shields, such as upper and lower metal layers connected via vias, to protect the conducting paths from EMI, and the use of wrap-around electrodes and flexible circuit board portions to facilitate stable electrical connections and thermal adaptation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the first conducting path is arranged between the first layer and the second layer of the multi-layer circuit board, then the electrical path is structurally shielded by the layers and is less susceptible to electromagnetic interference (EMI), but the device complexity increases due to the multi-layer structure and via connections
Solution Approach 1:
The first conducting path is nested within the multi-layer circuit board structure, positioned between the first and second layers. This nesting arrangement provides structural shielding while maintaining electrical connectivity, resolving the contradiction between EMI protection and device complexity.
Solution Approach 2:
The multi-layer circuit board acts as an intermediary structure that shields the conducting path from external electromagnetic fields. The layers and via connections serve as mediating elements that provide both protection and electrical connectivity, balancing EMI shielding with circuit functionality.
2Object-affected harmful factors
If upper and lower electrically conducting layers are added to cover the first layer and second layer surfaces, then shielding from external electromagnetic fields is enhanced, but the manufacturing complexity and cost increase
Solution Approach 1:
The upper and lower electrically conducting layers are merged with the multi-layer circuit board structure through via connections. This integration combines the shielding function with the existing circuit board manufacturing process, reducing the impact of increased manufacturing complexity.
Solution Approach 2:
The electrically conducting layers serve multiple functions: they provide EMI shielding, establish electrical references, and enable connections to the conducting paths. This multi-functionality justifies the added manufacturing complexity by delivering multiple benefits from additional structures.
3Stability of the object's composition
If the first ultrasound transducer is mechanically fixed to the circuit board with electrically conducting fixing means, then stable mechanical attachment is achieved, but the electrical connection reliability may be compromised if the fixing means does not provide adequate electrical contact
Solution Approach 1:
The electrically conducting fixing means combines mechanical fixation and electrical connection functions into a single integrated element. This merging ensures that the same structure providing mechanical stability also ensures reliable electrical contact, resolving the contradiction between mechanical attachment and electrical connection reliability.
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 solution effectively shields the conducting paths from external electromagnetic interference, improving data quality and allowing for stable electrical connections and thermal flexibility, thereby enhancing the performance of the ultrasound flow meter units.
Implementation Method 1
The upper electrically conducting layer and the lower electrically conducting layer at least partially shield the first conducting path from external electromagnetic fields which could otherwise penetrate through the first layer and/or the second layer, and electrically influence the first conducting path
Implementation Method 2
a first ultrasound transducer formed from a monolithic body of piezoelectric material having a first electrical terminal and a second electrical terminal
Implementation Method 3
one or more ultrasound transducers, used for sending and receiving an ultrasound signal
Data Source
AI summary
An ultrasound flow meter unit arranged to measure a fluid flow rate is provided, where the unit comprises a circuit board 502 which comprises an electronic circuit, a first ultrasound transducer 506 and a first conducting path 564 electrically connected to first ultrasound transducer and the electronic circuit, wherein the circuit board is a multi-layer circuit board and the first conducting path 564 is arranged at least partially between a first layer 581 and a second layer 582. In a further embodiment, there is provided an upper electrically conducting layer 586 and/or a lower electrically conducting layer 588 which substantially covers, respectively, the upper surface of the first layer 581 and the lower surface of the second layer 582.