Polysiloxane films and methods of making polysiloxane films
A method of forming a polysiloxane film on a substrate comprises polymerizing a siloxane monomer in a reaction chamber containing the substrate. The polymerization is catalyzed by a 30-60 W radio frequency plasma, the pressure in the reaction chamber during the polymerization is 100-400 mTorr, the residence time of the siloxane monomer in the reaction chamber is 5-120 minutes, the siloxane monomer is heated to 30-200° C. before entering the reaction chamber, and the polymerization is carried out at a temperature of 30-100° C.
1. A method comprising:
forming an electrically isolating imperforate polysiloxane film on a substrate and an electrical component of the substrate to completely cover and electrically isolate an active feature of at least one of the substrate and the electrical component from environmental electrical interaction, the polysiloxane film comprising pendant grafts forming at least one electron cloud to resist ion diffusion and electron conduction through the polysiloxane film;
wherein forming the polysiloxane film comprises:
polymerizing a siloxane monomer in a reaction chamber containing the electrical component on the substrate; and
wherein the polymerization is catalyzed by a 30-60 W radio frequency plasma and the pressure in the reaction chamber during the polymerization is 100-400 mTorr.
2. The method of claim 1 , wherein the residence time of the siloxane monomer in the reaction chamber is 5-120 minutes.
3. The method of claim 1 , wherein the residence time of the siloxane monomer in the reaction chamber is 5-60 minutes.
4. The method of claim 1 , wherein the siloxane monomer is heated to 30-200° C. before entering the reaction chamber.
5. The method of claim 1 , wherein the siloxane monomer is heated to 75-140° C. before entering the reaction chamber.
6. The method of claim 1 , wherein the polymerization is carried out at a temperature of 30-100° C.
7. The method of claim 1 , wherein the pressure in the reaction chamber during the polymerization is 175-350 mTorr.
8. The method of claim 1 , wherein:
the residence time of the siloxane monomer in the reaction chamber is 5-120 minutes;
the siloxane monomer is heated to 30-200° C. before entering the reaction chamber; and
the polymerization is carried out at a temperature of 30-100° C.
9. The method of claim 1 , wherein:
the pressure in the reaction chamber during the polymerization is 175-350 mTorr;
the residence time of the siloxane monomer in the reaction chamber is 5-60 minutes;
the siloxane monomer is heated to 75-140° C. before entering the reaction chamber; and
the polymerization is carried out at a temperature of 30-100° C.
10. The method of claim 1 , wherein the reaction chamber comprises an inert gas.
11. The method of claim 10 , wherein the gas further comprises oxygen,
wherein oxygen is present as at least one of oxygen (O 2 ), ozone (O 2 ), nitrous oxide (N 2 O), carbon dioxide (CO 2 ), water (H 2 O), and mixtures thereof.
12. The method of claim 1 , wherein the polymerizing comprises polymerizing a plurality of types of siloxane monomers.
13. The method of claim 1 , wherein the siloxane monomer comprises fluorine.
14. The method of claim 1 , wherein the polysiloxane film has a thickness of 0.3 to 1.5 microns.
15. The method of claim 1 , wherein the polysiloxane film has a thickness of 0.5 to 1.1 microns.
16. The method of claim 1 , wherein the polysiloxane film has a thickness of at most 1.1 microns.
17. The method of claim 1 , further comprising swelling the polysiloxane film with a non-volatile diluent.
18. The method of claim 17 , wherein the non-volatile diluent comprises an organic monomer or an organic oligomer.
19. The method of claim 1 , wherein the siloxane monomer comprises at least one of a linear siloxane monomer and a cyclic siloxane monomer, the linear siloxane monomer having a formula comprising one of (X1) n Si(R1) 4-n in which n=1, 2, or 3, (X1)Si(R1) 2 OSi(R1) 2 (X1), and (X1)(Si(R1) 2 O) 2 Si(R1) 2 (X1), the cyclic siloxane monomer having a formula comprising [OSi(R1) 2 ] m in which m=3 or 4, wherein X1 comprises one of chloro and OR2, each R1 comprises one of an amino, hydroxyl, mercapto, alkoxy, alkyl, cycloalkyl, aryl, and heteroaryl, and each R2 comprises an alkyl group.
20. The method of claim 1 , wherein the polysiloxane film has a leakage current of at most 0.01 mA at 10 V and a contact resistance of at least 0.01 ohms at 1.0 mm of pogo pin compression under a 1.0 N load.