Ultrasound Transducer Sputtered Electrodes and Thermal Management

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Solution Overview

Problem

Diagnostic ultrasound transducers face challenges in being physically robust, thermally tolerant, and cost-effective, especially for use in field or developing country settings, with issues related to cross-talk, impedance, heat management, and manufacturing complexity, while existing solutions often require cumbersome cabling and soldering for electrical connections.

Innovation Solution

A diagnostic ultrasound transducer design featuring a planar backing block with a rigid printed circuit board and sputtered conductive layers for solder-free electrical contact, combined with metallic members for thermal management and grounding, allowing for efficient heat dissipation and reduced manufacturing complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If strong lead wires are used to provide physical robustness, then the transducer cable becomes bulky and stiff, but this makes it cumbersome for operators to maneuver over the patient's body

Engineering Contradiction:
Improvephysical robustnessVSAvoidcable maneuverability
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The patent removes traditional lead wires and circuit boards from the transducer structure, extracting the electrical connection function to an external processor. This eliminates the bulky cabling issue while maintaining robustness through the integrated piezoelectric array design.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The piezoelectric elements serve multiple functions: they generate ultrasonic waves for imaging and simultaneously detect returning echoes. This multi-functionality eliminates the need for separate transmitting and receiving components, reducing overall structure complexity and cable requirements.

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

2Ease of operation

If fine wires or traces are used to allow for a light, flexible cable, then ease of operation improves, but these fine wires are more prone to breaking

Engineering Contradiction:
Improvecable flexibilityVSAvoidwire integrity
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent completely removes the wire and trace infrastructure by using direct electrical contact through conductive adhesive between piezoelectric elements and the circuit board. This eliminates the reliability issue of fine wires while maintaining cable flexibility through reduced mass.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Conductive adhesive serves as an intermediary material that provides reliable electrical connection between piezoelectric elements and the circuit board without requiring fragile wire bonds. This mediator maintains both electrical integrity and mechanical flexibility.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of manufacture

If transducer structures are specially designed for certain materials in the backing layer, then manufacturing with those materials is optimized, but this makes it difficult to adapt to new materials without costly changes

Engineering Contradiction:
Improvemanufacturing optimizationVSAvoidmaterial adaptability
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent segments the transducer into modular components: piezoelectric elements, backing layer, matching layers, and circuit board. This modular design allows independent selection and replacement of materials in each layer without affecting other components, enabling easy adaptation to new materials.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The circuit board design with conductive adhesive patterns provides a universal interface that can accommodate different piezoelectric element materials and configurations. The same basic structure works with various backing layer materials, providing manufacturing versatility.

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

4Reliability

If traditional soldering methods are used for electrical connections, then reliable electrical contact is achieved, but manufacturing complexity and the risk of electrical failures increase

Engineering Contradiction:
Improveelectrical contact reliabilityVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical soldering process with a chemical bonding method using conductive adhesive. This substitution eliminates the complexity of soldering operations, equipment, and quality control while maintaining reliable electrical and mechanical contact.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

Conductive adhesive acts as an intermediary material that simultaneously provides mechanical bonding and electrical conduction between piezoelectric elements and the circuit board. This single material replaces the multiple components and processes required in traditional soldering.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 provides a robust, thermally tolerant, and cost-effective ultrasound transducer with improved electrical and thermal performance, reducing manufacturing complexity and the risk of electrical failures, while maintaining high image quality and ease of use.

Implementation Method 1

piezoelectric elements within a transducer are formed as an array and are selectively activated electrically to produce a desired scan pattern

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

The same array is then switched to receive the return signals, which are then converted back into electrical signals

Methodology Applied
Scientific EffectConverse piezoelectric effect: Converse Piezoelectric Effect

Implementation Method 3

an area of electrically conductive material is formed, for example by sputtering, on a corresponding portion of a contact surface of the backing block

Methodology Applied
Scientific EffectSputtering: Sputtering

Implementation Method 4

metallic members for thermal management and grounding, allowing for efficient heat dissipation

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP2025414B1Ultrasound imaging transducer and corresponding manufacturing method
Publication Date: 2016.07.27 SHENZHEN MINDRAY BIO MEDICAL ELECTRONICS CO LTD
  • EP2025414B1 patent drawingFigure 1~2
  • EP2025414B1 patent drawingFigure 3~4
  • EP2025414B1 patent drawingFigure 5

AI summary

An ultrasound transducer (100) includes an array (114) of PZT elements (115) mounted on a non-recessed distal surface of a backing block (110). Between each element and the backing block is a conductive region (125, 126) formed as a portion of a metallic layer sputtered onto the distal surface. Traces (104, 105) on a longitudinally extending circuit board (102) - preferably, a substantially rigid printed circuit board, which may be embedded within the block - connect the conductive region, and thus the PZT element, with any conventional external ultrasound imaging system. A substantially "T" or "inverted-L" shaped electrode is thereby formed for each element, with no need for soldering. At least one longitudinally extending metallic member (120, 121) mounted on a respective lateral surface of the backing block forms a heat sink and a common electrical ground. A thermally and electrically conductive layer (125), such as of foil, transfers heat from at least one matching layer mounted on the elements to the metallic member.