Via-Based Temperature Detection in Liquid Ejection Heads
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid ejection heads with temperature detection elements based on wire and via connections suffer from low sensitivity due to high connection resistance, which hinders accurate temperature detection and control of heating resistance elements.
Innovation Solution
The element substrate incorporates a layered structure with a temperature detection element formed as a via in a first insulation layer, electrically insulated from the heating resistance element by a second insulation layer, allowing for enhanced sensitivity by reducing connection resistance and increasing the resistance of the temperature detection element through a meandering shape and optimized thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a temperature detection element is formed by connecting two wires to each other in series with a via therebetween, then the temperature detection element can be integrated into the element substrate, but the connection resistance of the wires and via becomes dominant, resulting in low detection sensitivity
Solution Approach 1:
The invention extracts the temperature detection function from the wire connection structure and creates a dedicated temperature detection element formed by a via filled with temperature detection material. This separates the temperature detection function from the wire connections, allowing the via to serve as both connection and sensing element, thereby reducing the influence of connection resistance on detection sensitivity.
Solution Approach 2:
The invention merges the wire connection function and temperature detection function into a single via structure. The via is filled with temperature detection material and serves both as an electrical connection path and as the temperature sensing element, eliminating the need for separate wire connections and reducing overall connection resistance.
2Ease of manufacture
If the connection resistance between wires and via is large (100 to 10000 times higher than material resistance), then the structure can be manufactured with standard processes, but it becomes difficult to detect the change in resistance of the temperature detection element caused by temperature change
Solution Approach 1:
The invention changes the resistance parameter by filling the via with temperature detection material that has appropriate resistivity characteristics. This material selection optimizes the resistance value to be suitable for temperature detection while maintaining compatibility with standard manufacturing processes for forming vias and filling them with conductive materials.
3Device complexity
If the temperature detection element uses wire and via connections, then the element substrate can be constructed with conventional layers, but the detection sensitivity is insufficient due to high connection resistance and other factors
Solution Approach 1:
The invention transitions from a planar wire connection structure to a vertical via-based structure. By utilizing the vertical dimension of the layered element substrate, the via provides a direct vertical path for both electrical connection and temperature detection, reducing the horizontal wire length and associated resistance that plague planar configurations.
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 enhances the sensitivity of temperature detection, enabling more precise control of the heating resistance element and improved ejection state monitoring in liquid ejection heads.
Implementation Method 1
A liquid ejection head of the heat ejection type ejects liquid droplets such as ink onto a recording sheet by using heat energy generated by a heating resistance element
Implementation Method 2
a temperature detection element (temperature sensor) that detects temperature... in a temperature detection element that detects a change in temperature on the basis of a change in electrical resistance of a constituent material
Data Source
AI summary
An element substrate has a layered structure including a heating resistance element, a first insulation layer where a temperature detection element constituted by a via is formed, and a second insulation layer provided between the heating resistance element and the temperature detection element which electrically insulates the heating resistance element and the temperature detection element.