Liquid Ejecting Head With Young's Modulus-Tuned Piezoelectric Layers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing piezoelectric-type liquid ejecting heads with stacked thin-film piezoelectric bodies face challenges in achieving optimal ejection characteristics due to limitations in Young's modulus and stress loads, particularly with the second thin-film piezoelectric body, which affects ejection performance and manufacturing stability.
Innovation Solution
The configuration of the liquid ejecting head includes a first thin-film piezoelectric body with a higher Young's modulus than the second thin-film piezoelectric body, along with a common electrode structure that balances stress loads and film-forming damage, enhancing ejection characteristics by optimizing the properties of both piezoelectric layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single-layer thin-film piezoelectric body is used, then the structure is simple and manufacturing is easier, but the displacement amount per unit voltage is small resulting in poor ejection characteristics
Solution Approach 1:
The piezoelectric body is divided into multiple thin-film layers (first and second thin-film piezoelectric bodies) with different Young's moduli, allowing each layer to contribute differently to the overall displacement while maintaining manufacturing feasibility through sequential deposition processes
2Manufacturing precision
If two thin-film piezoelectric bodies are stacked with equal properties, then the displacement amount per unit voltage increases, but stress loads and film-forming damage increase particularly in the second layer
Solution Approach 1:
The first thin-film piezoelectric body is designed with a higher Young's modulus than the second layer, creating local property differentiation that allows the first layer to bear more stress while the second layer provides additional displacement with reduced stress concentration, preventing film-forming damage
Solution Approach 2:
By changing the Young's modulus parameter between the two thin-film layers (first layer has higher Young's modulus than the second), the stress distribution is optimized to reduce film-forming damage while maintaining high displacement output
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 configuration improves ejection performance by increasing displacement amounts and reducing stress and film-forming damage, resulting in enhanced ejection characteristics and manufacturing stability of the piezoelectric elements.
Implementation Method 1
A piezoelectric method uses piezoelectric elements configured to cause a diaphragm constituting a part of wall surfaces of pressure compartments to vibrate. The liquid with which the pressure comparts are filled is ejected from nozzles by causing the diaphragm to vibrate by means of the piezoelectric elements.
Implementation Method 2
a Young's modulus of the first thin-film piezoelectric body is greater than a Young's modulus of the second thin-film piezoelectric body
Data Source
AI summary
A liquid ejecting head is disclosed that includes a pressure compartment substrate that includes pressure compartments, a diaphragm, a first common electrode to provide a reference voltage to the pressure components, first and second thin-file piezoelectric bodies, an individual electrode for each of the pressure compartments for applying a drive voltage, and a second common electrode to the pressure compartments and to which the reference voltage is applied. The pressure compartment substrate, the diaphragm, the first common electrode, the first thin-film piezoelectric body, the individual electrode, the second thin-film piezoelectric body, and the second common electrode are stacked in this order from a lower side toward an upper side, and a Young's modulus of the first thin-film piezoelectric body is greater than a Young's modulus of the second thin-film piezoelectric body.