Piezoelectric Vibration Unit Thickness Reduction via Hole Nesting

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Solution Overview

Problem

Existing vibration units are large in size due to their thickness, which limits their compactness and efficiency in applications such as pressure detection and vibration generation.

Innovation Solution

A vibration unit design featuring a first case portion with a low modulus of elasticity and a second case portion with a plate shape, where a vibration device with a sheet-shaped piezoelectric element and vibration plate is arranged, allowing the piezoelectric element to expand and contract in the in-plane direction, and supported by the second case portion, reducing the overall thickness and size through strategic hole placement and bonding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the vibration unit uses a conventional structure with piezoelectric element, disk, and circuit board arranged in order from the overlay, then the vibration function is achieved, but the thickness and overall size become large

Engineering Contradiction:

Improvesize of vibration unitVSAvoidstructural complexity

Core Design Contradiction:

Volume of moving objectVSDevice complexity

Solution Approach 1:

The patent combines the disk and circuit board into a single integrated component where the circuit board serves both as the structural disk and as the mounting platform for electronic components. This integration eliminates the need for separate disk and circuit board layers, directly reducing the overall thickness and volume of the vibration unit while maintaining all necessary functions.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The piezoelectric element is positioned to extend into the hollow portion of the integrated circuit board structure, nesting it within the existing component layout. This arrangement allows the piezoelectric element to be housed within the space already defined by the circuit board, reducing the need for additional external space and minimizing the overall unit volume.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Area of stationary object

If multiple vibration devices are arranged in the vibration unit, then the vibration coverage is improved, but the mutual influence between vibrations increases

Engineering Contradiction:

Improvevibration coverage areaVSAvoidmutual vibration influence

Core Design Contradiction:

Area of stationary objectVSObject-generated harmful factors

Solution Approach 1:

The patent divides the vibration unit into multiple independent vibration devices, each with its own piezoelectric element and localized vibration plate. This segmentation allows each device to operate independently with minimal interference from others, as each is positioned to target specific areas of the overlay, thereby expanding total vibration coverage while reducing harmful mutual influences.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Each vibration device is designed with localized characteristics, where the piezoelectric element and vibration plate are positioned to create focused vibration zones. By optimizing the local configuration of each device independently, the patent achieves broad overall coverage while ensuring that each localized area vibrates with minimal interference from adjacent devices.

Inventive Principle:

Principle #3Local quality

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 design achieves a significant reduction in the size of the vibration unit while minimizing mutual influence between vibration devices and ensuring efficient vibration transmission, allowing for compact and effective operation.

Implementation Method 1

a piezoelectric element having a sheet shape which is arranged on the other main surface of the vibration plate and can expand and contract in an in-plane direction of the vibration plate

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

a vibration plate of which one main surface is in contact with the first case portion, and a piezoelectric element... which can expand and contract in an in-plane direction of the vibration plate

Methodology Applied

Scientific EffectMechanical vibration: Vibration

Data Source

PatentUS11323046B2Vibration unit having a piezoelectric element as the vibration source

Publication Date: 2022.05.03 TDK CORP

AI summary

In a vibration unit, a piezoelectric element enters an internal space of a through hole; and thereby, a second case member can be arranged proximate to a first case member. Therefore, a thickness of the vibration unit can be reduced, namely, a height of the vibration unit can be reduced. As described above, since the thickness of the vibration unit is reduced, a size of the vibration unit can be reduced.