Grooved Conductive Traces for Transparent High-Aspect-Ratio Patterning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for forming conductive traces on substrates, such as antennas or EMI shields, often require expensive and complex photolithography processes, and struggle to achieve high aspect ratios and optical transparency while maintaining electrical conductance.
Innovation Solution
A process involving a conductive seed layer disposed at the bottom of grooves in a substrate, with a unitary conductive body formed by electroplating, allowing for high aspect ratio traces that enhance electrical conductance and optical transparency, and optionally backfilling with non-conductive materials for durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If photolithography is used to form conductive traces on a substrate, then the traces can be formed with controlled patterns, but the process becomes expensive and complex
Solution Approach 1:
The conductive trace is divided into two distinct parts: a conductive seed layer formed at the bottom of grooves in the substrate, and a unitary conductive body formed by electroplating on top of the seed layer. This segmentation allows each part to be optimized independently - the seed layer provides adhesion and initial conductivity, while the electroplated body provides the desired conductance and pattern control, eliminating the need for complex photolithography processes.
Solution Approach 2:
The patent replaces the photolithography process (which uses light and chemical etching) with a direct electroplating process. By forming grooves in the substrate and depositing conductive material directly through electroplating, the method substitutes a simpler mechanical/electrical process for the complex optical-chemical photolithography system, reducing process complexity while maintaining manufacturing precision.
2Reliability
If conventional methods are used to form conductive traces, then the traces can provide electrical conductance, but achieving high aspect ratios and optical transparency is difficult
Solution Approach 1:
The conductive trace structure transitions from a planar surface-mounted trace to a three-dimensional structure embedded within grooves in the substrate. By utilizing the vertical dimension and forming grooves that extend into the substrate, the patent achieves high aspect ratios while maintaining electrical conductance through the electroplated conductive body that fills the groove volume, and preserves optical transparency by confining the conductive material to specific regions rather than covering the entire surface.
Solution Approach 2:
The substrate is modified locally by forming grooves only in specific regions where conductive traces are needed. The conductive seed layer and unitary conductive body are then formed only within these grooves, creating localized conductive paths that maintain the overall transparency of the substrate while providing the required electrical conductance in specific areas.
3Reliability
If conductive traces are formed with higher conductance, then electrical performance improves, but the complexity of forming high aspect ratio traces increases
Solution Approach 1:
The electroplating process is self-regulating and automatically conforms to the groove geometry and seed layer pattern. The electroplated conductive body grows uniformly from the seed layer, naturally filling the groove volume and forming the desired high aspect ratio structure without requiring additional masking or patterning steps. This self-service characteristic of electroplating simplifies the formation of high conductance traces with high aspect ratios.
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 method enables the formation of conductive traces with improved control over trace profiles, increased electrical conductance, and enhanced durability, while maintaining high transparency and flexibility, suitable for applications like antennas and EMI shields.
Implementation Method 1
a unitary conductive body formed by electroplating
Data Source
AI summary
A patterned conductive article includes a substrate having a first groove therein; a conductive seed layer disposed in the first groove; and a unitary conductive body disposed at least partially in the first groove. The conductive seed layer covers at least a majority of a bottom surface of the first groove, and the unitary conductive body covers the conductive seed layer and at least a majority of side surfaces of the first groove. In a plane through the unitary conductive body that is parallel to and separate from the conductive seed layer, the unitary conductive body has a lower first line edge roughness at a first interface with the side surfaces and the conductive seed layer has a higher second line edge roughness at an edge of the conductive seed layer.