Vented Insert Fluid Cartridge for Chip Flatness and Crack Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional fluid cartridges experience mechanical stress and cracking due to plastic swelling and thermal expansion mismatch, leading to ejection head chip defects and inaccurate fluid ejection.
Innovation Solution
A fluid cartridge design featuring a ceramic or epoxy molding compound insert with air vents, which provides a stable bonding surface for the ejection head chip, reducing mechanical stress and allowing for a wider range of fluids to be used without cracking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a plastic cartridge body is used for fluid ejection, then the cartridge can be easily manufactured and cost-effective, but the plastic material swells when exposed to solvent-based fluids causing mechanical stress and ejection head chip cracking
Solution Approach 1:
The cartridge is divided into two distinct parts: a plastic outer cartridge body and a separate insert made of swelling-resistant material. The insert contains the fluid supply channel and bonding surface, while the plastic body provides structural housing. This segmentation allows each component to be optimized for its specific function without compromising the other.
Solution Approach 2:
The insert acts as an intermediary component between the plastic cartridge body and the ejection head chip. It provides a chemically stable bonding surface that is compatible with solvent-based fluids, while the plastic body remains as the outer structure. The insert mediates the interaction between the plastic material and aggressive fluids, preventing direct contact and swelling.
2Strength
If the die bond adhesive is cured at elevated temperature, then the bonding strength is improved, but the mismatch of coefficient of thermal expansion causes cartridge body swelling and ejection head chip bowing
Solution Approach 1:
The insert is made from a material with specific local properties (coefficient of thermal expansion) that match the ejection head chip. This local quality match at the bonding interface ensures that during elevated temperature curing, the insert and chip expand at similar rates, preventing chip bowing while still allowing strong adhesive bonding.
3Reliability
If air vents are added to the insert, then trapped gas during adhesive curing is eliminated preventing defects, but the insert structure becomes more complex
Solution Approach 1:
The insert incorporates porous features in the form of air vents or channels that allow trapped gas to escape during adhesive curing. These porous structures are strategically positioned to provide gas escape pathways without compromising the structural integrity or dimensional stability of the insert. The porosity is localized and controlled, maintaining overall simplicity.
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 insert maintains ejection head chip flatness and prevents cracking, ensuring accurate fluid ejection and compatibility with various fluids, while minimizing gas channels that could cause leakage or cross-contamination.
Implementation Method 1
a dimensionally stable surface for attaching and ejection head chip thereto that has a coefficient of thermal or mechanical expansion similar to that of the silicon substrate of the ejection head chip
Implementation Method 2
a plurality of air vents adjacent to the die bond surface
Data Source
AI summary
A fluid cartridge having a plastic fluid body, a bottom wall having a fluid supply opening therein. An insert is adhesively fastened to the bottom wall. The insert has a fluid supply slot therein corresponding to the fluid supply opening in the bottom wall, a die bond surface adjacent to the fluid supply slot for adhesively fastening an ejection head chip thereto, and a plurality of air vents adjacent to the die bond surface. The insert is a material selected from an epoxy molding compound and a ceramic material. An ejection head chip is adhesively fastened to the die bond surface of the insert.