Piezo Actuator Circuit Layout for Dielectric Breakdown Tolerance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Piezo actuators in fluid control valves used in semiconductor manufacturing can experience sudden dielectric breakdown, leading to a complete stop in flow rate control, which is problematic and difficult to recover from during processes.
Innovation Solution
A piezo actuator configuration with piezo blocks alternately stacked with ceramic and electrode layers, connected in parallel to a power source with limiting resistors in series, prevents voltage drop by limiting current and allowing continued operation of unaffected blocks, enabling provisional operation even with dielectric breakdown.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If piezo elements are connected in parallel to increase displacement, then the piezo actuator achieves sufficient extension/contraction range, but dielectric breakdown in one element causes complete failure of the actuator
Solution Approach 1:
The piezo actuator is divided into multiple independent piezo blocks (first, second, third blocks) that can operate independently. Each block is connected to the power source through limiting resistors, creating electrically independent circuits. When dielectric breakdown occurs in one block, the other blocks continue to function, maintaining partial actuator operation and preventing complete failure.
2Reliability
If limiting resistors are added in series to each piezo block, then reliability is improved by preventing voltage drop during dielectric breakdown, but device complexity increases
Solution Approach 1:
Limiting resistors are introduced as intermediary components in series with each piezo block. These resistors act as protective mediators that limit current flow when dielectric breakdown occurs in any block, preventing voltage drop that would affect other blocks. This simple intermediary component effectively isolates failures and maintains operational continuity.
3Productivity
If a single piezo element fails due to dielectric breakdown, then the actuator stops completely, but continuous operation is needed for semiconductor manufacturing processes
Solution Approach 1:
The circuit is designed with limiting resistors in advance to cushion against the harmful effects of dielectric breakdown. This preemptive protective measure ensures that when breakdown occurs, the current is limited and voltage is maintained for other blocks, allowing the system to continue operating and complete ongoing semiconductor manufacturing processes without interruption.
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 ensures continuous operation of the piezo actuator, preventing sudden stops and allowing for controlled gas supply during semiconductor processes, enabling timely replacement and minimizing process disruptions.
Implementation Method 1
The piezo blocks are formed by alternately stacking a piezoelectric ceramic layer and an electrode layer
Data Source
AI summary
A piezo actuator is provided which is capable of continuing a provisional operation at least in a limited movable range without bringing an operation to a complete stop even upon occurrence of dielectric breakage. The piezo actuator includes a plurality of piezo blocks and a driving circuit. The piezo blocks are formed by alternately stacking a piezoelectric ceramic layer and an electrode layer. The driving circuit is connected to the piezo blocks. The piezo blocks are arranged in an extension/contraction direction. The driving circuit includes a power source part to which the piezo blocks are individually connected in parallel, and a plurality of limiting resistors respectively disposed in series to the piezo blocks.