Liquid Ejection Head Groove Support for Substrate Rigidity
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Solution Overview
Problem
The existing ink jet recording heads face issues with ink bleeding or color mixing due to residual washing solution, deformation of the recording element substrate caused by thermal expansion differences, and reduced rigidity leading to quality issues, especially when the size of the recording element substrate is minimized to reduce costs.
Innovation Solution
A liquid ejection head design featuring a recording element substrate with an ejection orifice, an electrical wiring substrate, and a support member with a groove portion around the joint, where the sealing material is applied to the connection and groove portions, ensuring partial exposure of the substrate sides without terminals to reduce internal stress and facilitate washing solution removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the size of the recording element substrate is diminished to reduce cost, then manufacturing cost is reduced, but the rigidity of the recording element substrate is lowered making it liable to deformation or breakage
Solution Approach 1:
The support member is segmented into a groove portion and a flat portion, creating distinct functional zones. The groove portion provides enhanced support and stress relief for the recording element substrate, while the flat portion provides a stable mounting surface. This segmentation allows the substrate to be smaller without compromising overall structural rigidity.
Solution Approach 2:
The groove portion is designed to receive and cushion the recording element substrate before it is fully mounted. This pre-cushioning structure absorbs thermal expansion stresses and mechanical shocks that would otherwise deform or break the smaller, more fragile substrate, thereby protecting it in advance against potential damage.
2Reliability
If sealing material is applied to seal the connection portion and groove portion, then sealing performance is improved, but internal stress increases causing deformation of the recording element substrate
Solution Approach 1:
The support member is divided into a groove portion and a flat portion, creating distinct functional zones. The groove portion provides enhanced support and stress relief for the recording element substrate, while the flat portion provides a stable mounting surface. This segmentation allows the substrate to be smaller without compromising overall structural rigidity.
Solution Approach 2:
The groove portion is designed to receive and cushion the recording element substrate before it is fully mounted. This pre-cushioning structure absorbs thermal expansion stresses and mechanical shocks that would otherwise deform or break the smaller, more fragile substrate, thereby protecting it in advance against potential damage.
3Reliability
If the recording element substrate is fully sealed with sealing material, then protection against ink corrosion is improved, but washing solution cannot be discharged causing ink bleeding or color mixing
Solution Approach 1:
The support member features local quality differentiation with a groove portion and a flat portion. The groove portion provides localized support and stress relief where needed, while the flat portion provides a stable mounting surface. This localized structural variation allows the substrate to maintain rigidity at minimal size without requiring complete sealing, thus preventing washing solution accumulation.
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 design enhances the stability and rigidity of the recording element substrate, prevents ink bleeding, and maintains high recording quality by minimizing internal stress and effectively discharging washing solutions, thus addressing the challenges of cost reduction and quality retention.
Implementation Method 1
Since the curing temperature of the sealing material is higher than room temperature, the sealing material is cured and shrunk before returned to room temperature to restrain the recording element substrate. A resin material is generally used in the support member due to the advantage that it can be cheaply produced, and the recording element substrate is mainly formed with a silicon material, so that both are different from each other in coefficient of thermal expansion.
Data Source
AI summary
A liquid ejection head includes a recording element substrate having a member with a liquid ejection orifice, and a substrate having an energy-generating element for ejecting the liquid; a wiring substrate including wirings connected to terminals that are formed along an end portion side of a surface of the substrate where the element is formed and are electrically connected to the element; and a support member including a support supporting the recording element substrate through adhesive, a groove formed along the support and a wiring support supporting the wiring substrate. A sealing material is applied to a connection portion between the terminals and wirings and is applied to a bottom surface of the groove formed on an end portion side of the surface where no terminal is formed. A part of a side of the substrate corresponding to the end portion side is exposed without being covered with the sealing material.