Liquid Ejection Head Sealant Containment via Adhesion Layer Wall
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Solution Overview
Problem
Existing liquid ejection heads face challenges in preventing sealant flow from the element substrate, leading to inadequate coverage of electric connection parts and potential exposure due to bubble formation during thermal curing.
Innovation Solution
The liquid ejection head incorporates a channel forming member to create a wall that reduces sealant flow, ensuring improved coverage of electric connection parts and enhancing electrical reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the adhesion layer is used to form a wall for preventing sealant flow, then the structure is simple and manufacturing is easy, but the wall height is insufficient causing sealant to overflow
Solution Approach 1:
The patent combines the adhesion layer and the sealant prevention wall into a single integrated structure. The wall is formed by extending the adhesion layer in the thickness direction, so that the adhesion layer serves dual purposes: providing adhesion between the element substrate and nozzle plate, and forming a wall to prevent sealant flow. This merging eliminates the need for a separate wall structure while achieving both adhesion and sealant containment functions.
Solution Approach 2:
The patent solves the insufficient wall height problem by extending the adhesion layer in the thickness direction (Z-direction) to form a protruding wall structure. This dimensional extension transforms the thin adhesion layer into a three-dimensional structure with sufficient height to contain the sealant, while maintaining the same material and manufacturing process.
2Reliability
If a separate wall structure is added to prevent sealant flow, then sealant containment is improved, but manufacturing complexity increases
Solution Approach 1:
The patent merges the wall formation process with the adhesion layer formation process. Both the adhesion layer and the wall are formed simultaneously from the same material using the same manufacturing steps (printing and drying), eliminating the need for separate manufacturing processes and reducing overall manufacturing complexity.
Solution Approach 2:
The adhesion layer is designed to serve multiple functions: providing adhesion between substrates and forming a sealant prevention wall. This multi-functionality reduces the total number of components and manufacturing steps, simplifying the overall manufacturing process while achieving reliable sealant containment.
3Reliability
If the sealant application amount is increased to ensure coverage, then coverage is improved, but the risk of overflow and bubble formation increases
Solution Approach 1:
The patent provides a pre-formed wall structure (the protruding adhesion layer) before sealant application. This wall acts as a barrier that contains the sealant within the element substrate area, allowing sufficient sealant to be applied for complete coverage of electric connection parts without risking overflow. The wall cushions against the harmful effect of excessive sealant application.
Solution Approach 2:
The protruding adhesion layer wall serves as an intermediary barrier between the sealant and the external environment. It allows the sealant to be contained and properly applied over the electric connection parts while preventing direct contact with areas where overflow would cause bubble formation and exposure of electrical components.
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 effectively prevents sealant flow, reduces the risk of bubble formation, and enhances the electrical reliability of the liquid ejection head by ensuring consistent coverage of the electric connection parts.
Implementation Method 1
The sealant is applied to the electric connection part, and the applied sealant is allowed to cure by heating or other methods to thereby cover the electric connection part.
Implementation Method 2
a wall for reducing flowing of a sealant is formed by using a channel forming member used to define a channel
Data Source
AI summary
A liquid ejection head includes an element substrate, an electric wiring board, and a sealant. The element substrate includes a substrate having a first face, and an element, a channel forming member, and a pad array that are disposed at the first face of the substrate. The element is configured to eject a liquid. The channel forming member includes a pressure chamber, and an ejection port communicating with the pressure chamber and through which the liquid is ejected. The pad array includes multiple pads electrically connected to the element and arranged along one side of the substrate. The electric wiring board is connected to each pad via an electric connection part. The sealant is disposed on the first face of the substrate, and surrounds the electric connection part. In the element substrate, the channel forming member has an opening, and the pad array is located within the opening.