Nano-coating protection method for electrical connectors
Introduced here is a plasma polymerization apparatus and process. Example embodiments include a vacuum chamber in a substantially symmetrical shape to a central axis. A rotation rack may be operable to rotate about the central axis of the vacuum chamber. Additionally, reactive species discharge mechanisms positioned around a perimeter of the vacuum chamber in a substantially symmetrical manner from the outer perimeter of the vacuum chamber may be configured to disperse reactive species into the vacuum chamber. The reactive species may form a polymeric multi-layer coating on surfaces of the one or more devices. Each layer may have a different composition of atoms to enhance the water resistance, corrosion resistance, and fiction resistance of the polymeric multi-layer coating.
1. A method for protecting an electrical connector from corrosive damage using a polymerization process to generate a plasma polymerization coating, the method comprising:
consistently moving, during a select period of time, the electrical connector within a reaction chamber;
during the select period of time:
applying a transition layer to the electrical connector by:
discharging a first monomer vapor into the reaction chamber,
generating a first reactive species from the first monomer vapor by discharging a first polymerization plasma into the reaction chamber, and
depositing the first reactive species to form the transition layer on a surface of the electrical connector, the transition layer having a first ratio of oxygen atoms to carbon atoms; and
applying a surface layer to the electrical connector by:
discharging a second monomer vapor into the reaction chamber,
generating a second reactive species from the second monomer vapor by discharging a second polymerization plasma into the reaction chamber, and
depositing the second reactive species to form the surface layer on a surface of the transition layer, the surface layer having a second ratio of oxygen atoms to carbon atoms that is less than the first ratio and that is greater than zero;
wherein the first monomer vapor and/or second monomer vapor include one or more of:
a first vapor comprising at least one organic monomer with a low dipole moment, wherein the low dipole moment of the first vapor reduces interference to electrical signals across the plasma polymerization coating;
a second vapor comprising at least one polyfunctional unsaturated hydrocarbon and hydrocarbon derivative monomer;
a third vapor comprising at least one monofunctional unsaturated fluorocarbon resin monomer; and
a fourth vapor comprising at least one organosilicon monomer in a Si—Cl, Si—O—C, or ring structure.
2. The method of claim 1 , further comprising controlling a ratio of the vapors based on differences in molecular bond energy, bond length and differences in vaporization temperatures of the monomer vapors.
3. The method of claim 1 , wherein the first monomer vapor and/or second monomer vapor includes cross-linked structure monomers that improve the strength and water resistance of the transition layer and/or the surface layer.
4. The method of claim 1 , further comprising varying the energy applied to the first monomer vapor, second monomer vapor, and/or a carrier gas according to differences in molecular bond energy, bond length, and differences in vaporization temperatures of different monomers to generate a compact transition layer and surface layer that provides water resistant and electrically conductive.
5. The method of claim 1 , wherein the first monomer and/or second monomer vapor are discharged into the reaction chamber at a rate of 10-1000 μL/min.
6. The method of claim 1 , wherein the first polymerization plasma and/or second polymerization plasma are formed by applying an electrical charge to a carrier gas in the reaction chamber, and wherein the first polymerization plasma and/or second polymerization plasma are deposited using pulse electrical discharge or periodic alternating electrical discharge.
7. The method of claim 6 , wherein, during the application of the surface layer, a duration of the pulse electrical discharge is 600-3,600 seconds, a power applied is 1-600 Watts, a frequency of the pulse electrical discharge is 1-1000 Hz, and a duty cycle of the pulse is from 1:1 to 1:500.
8. The method of claim 6 , wherein during the application of the surface layer, a duration of the periodic alternating electrical discharge is 600-3,600 seconds, a power applied is 1-600 Watts, and an alternating frequency is 1-1000 Hz.
9. The method of claim 1 , further comprising applying an electrical charge to a carrier gas to generate the first and/or second polymerization plasma.
10. The method of claim 9 , wherein the carrier gas includes an inert gas of argon (Ar) atoms.
11. The method of claim 1 , wherein the transition layer and/or surface layer comprise one or more of: carbon, fluorine, oxygen, silicon, and hydrogen atoms.
12. The method of claim 1 , wherein the first ratio of oxygen to carbon atoms of the transition layer is between 1:3 to 1:20.
13. The method of claim 1 , wherein the first reactive species and/or second reactive species are free radicals that are released from the first monomer vapor and/or second monomer vapor when energy is transferred from the first polymerization plasma and/or second polymerization plasma to the first monomer vapor and/or second monomer vapor.
14. The method of claim 13 , wherein the free radicals are polymerized on the surface of the electrical connector to form a polymer coating.
15. The method of claim 1 , wherein the electrical connector is a USB™ Type-C connector, a micro-USB™ connector, aLighting connector, an HDMI™ connector, a flexible printed circuit (FPC) connector, a board-to-board (BTB) connector, a probe connector, or a radio frequency (RF) coaxial connector.
16. The method of claim 1 ,
wherein the first monomer vapor includes the second vapor and/or the fourth vapor; and
wherein the second monomer vapor includes the first vapor and/or the third vapor.