Laminate Constructs for Micro-Fluid Ejection Heads
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current micro-fluid ejection head technologies face challenges with ceramic substrates, including high dimensional tolerances, limited thermal conductivity, electrical functionality limitations, and manufacturing complexities, which compromise precision and thermal dissipation, especially in larger printing swaths and chip arrays.
Innovation Solution
The use of laminate constructs combining the mechanical substrate function of a ceramic base with the electrical function of a printed circuit board (PCB), featuring vertically configured wiring layers interspersed with non-conductive layers like carbon fiber, supports ejection chips and improves thermal conductivity and rigidity, eliminating the need for ceramic components and reducing assembly stresses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If ceramic substrates are used for ejection heads, then mechanical stability and low thermal expansion are improved, but manufacturing precision and dimensional tolerances worsen due to shrinkage during firing
Solution Approach 1:
The patent uses a composite substrate combining ceramic base material with metal traces and dielectric layers. This composite structure maintains the low thermal expansion and mechanical stability of ceramic while allowing precise positioning of fluid features through metal traces that can be accurately deposited on the ceramic surface, compensating for the ceramic's inherent dimensional variability from firing shrinkage.
2Strength
If alumina-based ceramics are used, then mechanical strength is improved, but thermal conductivity and electrical functionality worsen due to limited thermal conduction and lack of electrical properties
Solution Approach 1:
The patent creates a composite structure where alumina ceramic provides mechanical strength, while embedded metal traces (such as tungsten or other low-conductivity metals) provide thermal conduction pathways and electrical functionality. The multi-layer construction with dielectric materials between metal traces enables both electrical isolation and thermal management, achieving reliable thermal and electrical performance while maintaining the mechanical advantages of alumina ceramic.
3Strength
If thicker die is used to increase board thickness, then structural rigidity is improved, but thermal dissipation worsens due to increased distance from heat source to substrate
Solution Approach 1:
The patent implements local quality by creating direct thermal pathways from the die to the ceramic substrate through thermal vias and conductive traces positioned strategically at heat-generating locations. The board structure is designed with varying thickness and enhanced thermal conduction only where needed for heat dissipation, while maintaining overall structural rigidity through the ceramic substrate and strategic reinforcement, rather than uniformly increasing thickness throughout the entire board.
4Adaptability or versatility
If PCB with FR4 material is used, then electrical functionality is improved, but compatibility with certain ink sets and corrosion protection worsen due to material limitations
Solution Approach 1:
The patent uses a composite construction where the substrate is ceramic (chemically inert and corrosion-resistant) rather than FR4, eliminating ink compatibility and corrosion issues. The electrical functionality is achieved through metal traces deposited on the ceramic surface with appropriate dielectric insulation layers, providing both electrical performance and chemical resistance to ink and cleaning solutions without the material limitations of organic PCB materials.
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 approach provides a lightweight, thermally conductive, and rigid substrate with improved corrosion protection, enabling more precise and efficient micro-fluid ejection while accommodating larger form factors and reducing manufacturing complexities.
Implementation Method 1
The use of laminate constructs combining the mechanical substrate function of a ceramic base with the electrical function of a printed circuit board (PCB), featuring vertically configured wiring layers interspersed with non-conductive layers like carbon fiber, supports ejection chips and improves thermal conductivity and rigidity
Implementation Method 2
Ceramics are relatively high modulus materials offering low coefficients of thermal expansion (CTEs). They are known to minimize chip bow in comparison to dies mounted directly on molded plastic substrates, especially when using epoxy die bond materials having elevated cure temperatures
Data Source
AI summary
A micro-fluid ejection head has an ejection chip to expel fluid. It connects to a laminate construct. The construct has vertically configured wiring layers interspersed with non-conductive layers, such as carbon fiber layers. An upper of the wiring layers electrically connects to the ejection chip. The upper layer may also support a planar undersurface of the chip directly on a surface or in a recessed pocket. The two can connect with a die bond, such as one having silica or boron nitride. Fluid connections exist between ink feed slots of the chip and the laminate construct. A silicon tile or other material may also fluidly interconnect with the two. A plastic manifold optionally supports the laminate construct and may fluidly connect to it. The wiring layers of the laminate contemplate ground, power, and various bond pads. Other construct layers contemplate prepreg or core FR4 layers.