Print Processing for Patterned Conductor and Semiconductor Materials
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional printing processes struggle to precisely control the critical dimensions of dielectric, conductor, and semiconductor features, often resulting in undesirable 'coffee ring' profiles due to ink spreading on non-absorbing substrates, which is detrimental for high-performance electronic devices.
Innovation Solution
The process involves controlling the solubility of dielectric and metal precursors in ink during dynamic drying by varying mass loading, viscosity, and irradiation, such as UV exposure, to pin the ink and form well-defined, anisotropic features with a dome-shaped profile.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional printing processes are used on non-absorbing substrates, then the printing process is simple, but the ink spreads and forms undesirable coffee ring profiles
Solution Approach 1:
The patent changes the physical-chemical parameters of the ink composition, specifically using precursors with controlled solubility and molecular weight (e.g., silanes with 5-1000 silicon atoms) to modify evaporation dynamics and prevent coffee ring formation, achieving uniform dome-shaped profiles while maintaining process simplicity
Solution Approach 2:
The patent utilizes phase transition during solvent evaporation, where the precursor solubility changes as the solvent evaporates, causing the precursor to precipitate and form pinned features. This controlled phase transition prevents uncontrolled spreading and coffee ring formation
2Ease of operation
If ink is printed on non-absorbing substrates without pinning mechanism, then the substrate is easy to work with, but the liquid ink moves and spreads until solvent evaporation
Solution Approach 1:
The patent incorporates pinning agents or uses precursor properties that create pinning points during the printing process itself, preventing subsequent ink movement. This preliminary stabilization action occurs as the ink is deposited, maintaining position stability without complicating substrate handling
Solution Approach 2:
The patent uses the solvent-precursor system as an intermediary mechanism where the solvent carries the precursor to the substrate, and the controlled evaporation of this intermediary system enables pinning through solubility changes, maintaining ease of operation while achieving stability
3Productivity
If evaporation rate is high at ink edges, then solvent removal is efficient, but liquid flows to edges forming coffee ring profile
Solution Approach 1:
The patent changes the molecular weight and solubility parameters of the precursor (using silanes with 5-1000 silicon atoms) to control the evaporation-drying dynamics. This modification ensures uniform precipitation throughout the ink volume even with high edge evaporation rates, maintaining both productivity and uniform dome-shaped profiles
Solution Approach 2:
The patent converts the harmful coffee ring effect into a beneficial uniform deposition process by using precursors that precipitate uniformly during evaporation. The high evaporation rate at edges, which normally causes coffee ring formation, is transformed into an efficient solvent removal mechanism that drives uniform precursor precipitation throughout the feature
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 allows for precise control of critical and non-critical dimensions of printed features, achieving uniform profiles and improved performance in electronic circuits and devices.
Implementation Method 1
precipitating the precursor (or a higher molecular weight or more insoluble derivative thereof) in the pattern to form a pinning line
Implementation Method 2
substantially evaporating the solvent to form the feature defined by the pinning line
Data Source
Figure 1A~1B
Figure 2
Figure 3~4
AI summary
Embodiments relate to printing features from an ink containing a material precursor. In some embodiments, the material includes an electrically active material, such as a semiconductor, a metal, or a combination thereof. In another embodiment, the material includes a dielectric. The embodiments provide improved printing process conditions that allow for more precise control of the shape, profile and dimensions of a printed line or other feature. The composition(s) and/or method(s) improve control of pinning by increasing the viscosity and mass loading of components in the ink. An exemplary method thus includes printing an ink comprising a material precursor and a solvent in a pattern on the substrate; precipitating the precursor in the pattern to form a pinning line; substantially evaporating the solvent to form a feature of the material precursor defined by the pinning line; and converting the material precursor to the patterned material.