Staggered Through Electrodes in Piezoelectric Actuator
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In liquid ejection apparatuses, the reduction of nozzle and pressure chamber arrangement pitches leads to increased proximity of through electrodes, resulting in a higher likelihood of shorts due to the limitations in reducing the diameter of through holes in the protector, making it difficult to achieve smaller electrode sizes without compromising the protective function and handling of the protector.
Innovation Solution
The arrangement of piezoelectric elements and through electrodes is staggered, with the distance between adjacent through electrodes being greater than the distance between adjacent piezoelectric elements, and the use of conductive adhesive with conductive particles to ensure electrical connection while maintaining mechanical integrity, thereby preventing shorts and allowing for efficient electrical conduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the arrangement pitch of pressure chambers and nozzles is reduced to achieve high-density configuration, then the size of the liquid ejection apparatus is reduced, but the distance between adjacent through electrodes is reduced, increasing the likelihood of shorts
Solution Approach 1:
The patent offsets through electrodes in the thickness direction (vertical dimension) to create staggered arrangements. This dimensional shift increases the spatial separation between adjacent through electrodes without expanding the planar footprint, thereby maintaining compact apparatus size while preventing shorts through enhanced vertical and diagonal spacing.
Solution Approach 2:
The patent employs asymmetric offset arrangements where even-numbered and odd-numbered through electrodes are displaced by different amounts in the thickness direction. This asymmetric configuration optimizes the minimum distance between adjacent through electrodes throughout the array, ensuring uniform short-prevention margins while maintaining high-density packaging efficiency.
2Length of moving object
If the diameter of through holes in the protector is reduced to enable smaller through electrode sizes, then the arrangement pitch of through electrodes can be reduced, but there is a limit to how much the diameter can be reduced, making it difficult to prevent shorts
Solution Approach 1:
Instead of further reducing the already minimized through hole diameter, the patent introduces offsetting in the thickness direction to increase separation distance. This approach maintains the small diameter necessary for high-density arrangements while using the vertical dimension to ensure adequate spacing that prevents shorts.
Solution Approach 2:
The patent introduces an insulating layer as an intermediary substance filling the through holes and extending beyond the conductor portions. This insulating mediator provides additional electrical isolation between adjacent through electrodes, enabling the use of smaller through hole diameters without compromising reliability against shorts.
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 effectively prevents shorts between adjacent through electrodes while maintaining the protective function and handling of the protector, allowing for reliable operation even at high-density electrode arrangements, thus ensuring the reliability and efficiency of the liquid ejection apparatus.
Implementation Method 1
a piezoelectric actuator including piezoelectric elements corresponding to the respective pressure chambers
Implementation Method 2
the use of conductive adhesive with conductive particles to ensure electrical connection
Data Source
AI summary
An actuator device includes: an actuator including piezoelectric elements arranged in a first direction and first contacts arranged in the first direction; a protector including a first wall opposed to the piezoelectric elements and a second wall coupled to the first wall and joined to a region of the actuator at which the first contacts are disposed; first connection terminals disposed on the first; and first through electrodes formed in the second wall to bring the first contacts and the first connection terminals into conduction with each other. A distance between two of the first through electrodes which respectively correspond to two of the piezoelectric elements which are adjacent to each other in the first direction is greater than a distance in the first direction between the two of the piezoelectric elements which are adjacent to each other in the first direction.