Liquid Ejecting Head Wiring Structure for Voltage Drop Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing liquid ejecting heads face a challenge with high resistance in the wiring that couples the common electrode to the wiring board, leading to voltage drop and delayed current supply, which affects the efficiency of liquid ejection.
Innovation Solution
The design incorporates a wiring structure with a first wiring portion above the pressure chamber substrate and a second wiring portion at the sealing substrate's lower surface, along with a third wiring portion between the piezoelectric elements, to reduce resistance and improve voltage supply to the common electrode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the wiring is provided above the pressure chamber substrate to electrically couple the common electrode to the wiring board, then the wiring is easier to manufacture and connect, but the resistance of the wiring becomes large causing voltage drop and current delay
Solution Approach 1:
The patent transitions the wiring from a two-dimensional layout above the pressure chamber substrate to a three-dimensional structure that extends through the substrate thickness. The wiring penetrates the pressure chamber substrate from the upper surface to the lower surface, utilizing the vertical dimension to create shorter electrical paths and reduce resistance while maintaining manufacturing feasibility.
Solution Approach 2:
Instead of routing the wiring only on the upper surface of the pressure chamber substrate as in conventional designs, the patent inverts the approach by having the wiring extend through the substrate to the lower surface. This inversion allows the wiring to leverage the substrate thickness as an advantage rather than a constraint, reducing the effective resistance path.
2Reliability
If the wiring is extended to reduce resistance, then the voltage supply improves, but the wiring structure becomes more complex
Solution Approach 1:
The pressure chamber substrate serves multiple functions: it provides the pressure chambers for liquid ejection and simultaneously acts as a medium through which the wiring can pass. This multi-functionality allows the wiring to utilize the substrate's existing structural volume without adding separate complex wiring channels, thereby reducing overall device complexity while improving electrical performance.
Solution Approach 2:
The patent merges the wiring path with the pressure chamber substrate structure. The wiring is integrated into the substrate rather than being a separate additive component, combining the electrical connection function with the mechanical support function of the substrate. This merging reduces the number of discrete components and simplifies the overall wiring structure.
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 reduces wiring resistance, suppresses voltage drop, and prevents current delay to the common electrode, enhancing the reliability and accuracy of liquid ejection.
Implementation Method 1
piezoelectric elements that provide the liquid in the piezoelectric elements with pressure variations
Data Source
AI summary
A liquid ejecting head includes: a sealing substrate provided in such a way as to cover the first piezoelectric element and the second piezoelectric element; a wiring board configured to apply a voltage to a common electrode, a first individual electrode, and a second individual electrode; a first wiring portion provided above the pressure chamber substrate and configured to electrically couple the common electrode to the wiring board; a second wiring portion provided at a lower surface of the sealing substrate and configured to electrically couple the common electrode to the wiring board; and a third wiring portion provided between the first piezoelectric element and the second piezoelectric element and configured to electrically couple the first wiring portion to the second wiring portion.