rGO Grafting on Microhole Sidewalls for Conductive Substrates
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Solution Overview
Problem
Existing methods for modifying non-conductive substrates and sidewalls of micro/nano holes with reduced graphene oxide (rGO) are complex and require multiple steps, involving toxic chemicals and organic solvents, which complicates the process and makes industrial mass production challenging.
Innovation Solution
A three-step process using an aqueous solution of a conditioner with an amino compound, followed by a graphene oxide solution, and then a reducing agent, to firmly bond reduced graphene oxide (rGO) onto substrate surfaces and sidewalls, achieving electrical conductivity without toxic chemicals or organic solvents, and facilitating industrial mass production at ordinary temperature and pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing methods are used to modify non-conductive substrates with rGO, then electrical conductivity can be achieved, but the process becomes complex and requires toxic chemicals and organic solvents
Solution Approach 1:
The patent extracts and eliminates toxic chemicals and organic solvents from the modification process, replacing them with aqueous solutions of amino compounds and reducing agents. This extraction of harmful substances simplifies the process while maintaining the ability to achieve stable electrical conductivity on non-conductive substrates and sidewalls.
Solution Approach 2:
The patent changes the chemical parameters of the modification process by using aqueous solutions with specific pH values (3-6 for GO solution, 3-10 for reducing agent solution) and controlled temperatures (35-80°C). These parameter changes enable the process to achieve rGO bonding without requiring toxic chemicals or organic solvents, thereby reducing complexity.
2Reliability
If existing methods are used to modify non-conductive substrates with rGO, then electrical conductivity can be achieved, but toxic chemicals and organic solvents are required
Solution Approach 1:
The patent converts the potentially harmful effect of requiring chemical solutions into a benefit by using aqueous solutions of amino compounds and reducing agents that are environmentally friendly. The amino compound layer provides a beneficial bonding interface for GO, and the reducing agent efficiently reduces GO to rGO, eliminating the need for toxic chemicals while maintaining conductivity.
Solution Approach 2:
The patent uses inexpensive and environmentally benign aqueous solutions instead of expensive and toxic chemical reagents. The amino compound and reducing agent solutions can be easily disposed of or degraded, eliminating the need for complex waste treatment systems associated with toxic chemicals.
3Reliability
If existing methods are used to modify non-conductive substrates with rGO, then electrical conductivity can be achieved, but the process is not scalable for industrial production
Solution Approach 1:
The patent segments the modification process into three simple sequential steps: (1) forming an amino compound layer, (2) bonding GO to the amino compound layer, and (3) reducing GO to rGO. This segmentation makes each step independently controllable and easily scalable for industrial production, eliminating the complexity of multi-step processes involving toxic chemicals.
Solution Approach 2:
The amino compound layer self-assembles on the substrate surface and provides automatic bonding sites for GO through its chemical properties. The reducing agent solution automatically reduces GO to rGO without requiring additional processing steps. This self-service mechanism simplifies the process and enables easy scaling for industrial applications.
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 process stabilizes conductivity, enhances mechanical strength, thermal conductivity, and electrical conductivity, allowing for successful electroplating and passing thermal shock tests, with the rGO layer being firmly bonded and easily producible in a simplified and environmentally friendly manner.
Implementation Method 1
contacting a substrate with an aqueous solution of a conditioner including an amino compound at 40-80° C. for 3-10 minutes to form a layer of the amino compound on surfaces of the substrate and sidewalls of the holes
Implementation Method 2
contacting the substrate with a graphene oxide (GO) solution for 5-10 minutes to chemically bond the GO with the amino compound
Implementation Method 3
contacting the substrate with a solution containing a reducing agent at 60-90° C. for 5-10 minutes to reduce the GO and modify the surfaces of the substrate with the reduced GO (rGO)
Data Source
AI summary
Non-conductive substrates, especially the sidewalls of micro/nano holes thereof are chemically modified (i.e., chemically grafted) by reduced graphene oxide (rGO). The rGO possesses excellent electrical conductivity and therefore the modified substrates become conductive, so that it can be directly electroplated. These rGO-grafted holes can pass thermal shock reliability test after electroplating. The rGO grafting process possesses many advantages, such as a short process time, no complex agent (i.e., no chelator), no toxic agents (i.e., formaldehyde for electroless Cu deposition). It is employed in an aqueous solution instead of an organic solvent, and therefore is environmentally friendly and beneficial for industrial production.