Substrate Joint Structure for Adhesive Wicking Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid ejection heads face challenges in downsizing and maintaining high reliability due to adhesive agent wicking, which blocks flow paths and reduces the density of ejection ports, as previous technologies like Japanese Patent Laid-Open No. 2001-162802 fail to effectively prevent adhesive agent wicking in recesses and through-holes.
Innovation Solution
A substrate joint body design with recessed portions on the second substrate to capture and contain protruding adhesive agent, minimizing wicking and allowing for reduced wall thickness between flow paths, thereby preventing blockage and enabling higher port density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If adhesive agent is used to join substrates, then substrates are securely connected, but adhesive agent wicks into engraved portions and blocks flow paths
Solution Approach 1:
The recessed portion is formed in advance in the second substrate at the position where adhesive agent may protrude. This preliminary structural preparation allows the adhesive agent to be contained within the recessed portion rather than wicking into the engraved portions, thus preventing flow path blockage while maintaining joint strength
Solution Approach 2:
The recessed portion acts as an intermediary structure between the joint portion and the engraved portions. It provides a designated space for the adhesive agent to reside, preventing direct contact and wicking into the flow paths, thus mediating between the need for strong adhesion and the need to keep flow paths clear
2Reliability
If adhesive agent entry region is provided to receive extruded adhesive agent, then adhesive agent blocking of recesses is prevented, but device size increases and reliability decreases
Solution Approach 1:
Instead of providing a separate adhesive agent entry region, the invention modifies the local quality of the second substrate by forming a recessed portion precisely at the joint portion where adhesive agent extrusion occurs. This localized modification contains the adhesive agent where it naturally protrudes, preventing wicking into engraved portions without adding extra structural elements, thus maintaining compact device size while improving reliability
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
The design effectively prevents adhesive agent wicking, allowing for a smaller and more reliable liquid ejection head with increased ejection port density by capturing protruding adhesive agent in recessed portions, thus enhancing performance and reliability.
Implementation Method 1
a recessed portion extending from a position exposed to the opening toward a position facing an opening edge of the opening on the second surface is formed in a third surface of the second substrate such that an adhesive agent protruding from a joint portion between the first substrate and the second substrate reaches the recessed portion
Data Source
AI summary
A substrate joint body includes a first substrate that has a first surface and a second surface facing away from the first surface and has an opening in the second surface, and a second substrate joined to the second surface with an adhesive agent, and the opening is covered with the second substrate, wherein a recessed portion extending from a position exposed to the opening toward a position facing an opening edge of the opening on the second surface is formed in a third surface of the second substrate such that an adhesive agent protruding from a joint portion between the first substrate and the second substrate reaches a third surface of the second substrate that faces the opening.