Liquid Ejection Head Support Structure for Thin Substrate Reliability
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Solution Overview
Problem
The structural reliability of liquid ejection heads is compromised due to the thinning of substrates with densely disposed eave-shaped terminals, leading to potential breakage and reduced electric reliability from ionic migration.
Innovation Solution
A configuration where a first substrate with projecting areas supports terminals, reinforced by a support member and frame, to enhance structural integrity and reduce wiring density, thereby preventing breakage and improving electric connection reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electric wirings are densely formed on the substrate to supply power to densely disposed energy generation elements, then high resolution imaging is achieved, but ionic migration occurs at the electric wiring parts lowering electric reliability
Solution Approach 1:
The patent moves the terminals from the substrate plane to the side surface of the substrate, creating a three-dimensional arrangement. This dimensional change separates the terminal location from the dense wiring area, allowing high-resolution imaging to be maintained while preventing ionic migration at the terminals since they are no longer in the high-density wiring region
2Ease of operation
If terminals are disposed at eave-shaped portions of the substrate to expose electric connection terminals, then electric connection is achieved, but the substrate portions become thin and prone to breakage
Solution Approach 1:
The patent introduces a sealing member as an intermediary component that performs multiple functions: it seals the terminal, provides mechanical support to the thin substrate portion, and prevents breakage. This intermediary element resolves the contradiction by allowing electric connection at eave-shaped portions while compensating for the reduced substrate strength through the sealing member's structural support
3Ease of operation
If substrates are thinned to accommodate densely disposed eave-shaped terminals, then electric connection terminals are exposed, but structural reliability is compromised leading to potential breakage
Solution Approach 1:
The patent applies beforehand cushioning by positioning the sealing member in advance to provide mechanical support and protection to the thinned substrate portions. The sealing member acts as a protective element that prevents breakage before it can occur, allowing the substrate to be thinned for terminal exposure while maintaining structural reliability through the pre-positioned sealing member
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 reinforced structure significantly enhances the structural reliability of liquid ejection heads, minimizing breakage and maintaining high electric reliability despite thin channel dimensions.
Implementation Method 1
an energy generation element that generates an energy for ejecting the liquid in the liquid chamber through the ejection port
Implementation Method 2
a support member joined to the first surface of the first substrate and having an opening at a position opposed to an area where the ejection port is formed; and a frame to which the support member is fixed
Data Source
AI summary
To improve the structural reliability of a liquid ejection head, the liquid ejection head includes a first substrate having ejection ports, liquid chambers, and energy generation elements, and a second substrate joined to a second surface of the first substrate situated opposite to its first surface. The first substrate includes projecting areas projecting from end portions of the second substrate in a planar direction perpendicular to a first-axis direction (z-axis direction). Terminals to be electrically connected to the energy generation elements are provided at the second surfaces of the projecting areas. A support member is joined to the first surface of the first substrate, has an opening at a position opposed to where the ejection ports are formed, and is fixed to the frame.