Reliable deposition of thin parylene

Patent metadata

Field	Value
Publication number	US-11077462-B2
Application number	US-201615331544-A
Country	US
Kind code	B2
Filing date	Oct 21, 2016
Priority date	Oct 23, 2015
Publication date	Aug 3, 2021
Grant date	Aug 3, 2021

Abstract

Apparatus, system, and method of depositing thin and ultra-thin parylene are described. In an example, a core deposition chamber is used. The core deposition chamber includes a base and a rigid, removable cover configured to mate and seal with the base to create the core deposition chamber and to define an inside and an outside of the core deposition chamber. The core deposition chamber also includes a conduit through a top of the cover. The conduit has a lumen connecting the inside to the outside of the core deposition chamber. The lumen has a length and a cross-section. The cross-section has a width between 50 μm and 6000 μm. The length is less than 140 times the cross-section width. The core deposition chamber can be placed in an outer deposition chamber and can achieve parylene deposition less than 1 μm thick inside the core deposition chamber.

First claim

What is claimed is:

1. A parylene deposition metering apparatus comprising:
a base;
a removable cover configured to mate and seal with the base to create an enclosed, core deposition chamber and define an inside and an outside of the core deposition chamber, the base and the cover configured to withstand an internal vacuum pressure relative to the outside of at least 3.0 Pa; and
a conduit through a top of the cover and about a center of the top of the cover, the conduit defined at least in part by a first fixed portion of the cover and a second fixed portion of the cover, the first fixed portion spaced apart from the second fixed portion by a distance between 50 μm and 6000 μm, the conduit having a lumen connecting the inside to the outside of the core deposition chamber, the lumen having a length and a cross-section, the cross-section having a width equal or smaller to the distance between the first fixed portion and the second fixed portion of the cover, the length being less than 140 times the cross-section width.

2. The parylene deposition metering apparatus of claim 1 , wherein the lumen comprises an unobstructed path between the inside and outside of the core deposition chamber, wherein the unobstructed path is along an axis that is perpendicular to a deposition surface that is in the inside of the core deposition chamber and that is configured to receive a substrate for parylene deposition, and wherein the cross-section is circular and the cross-section width is a diameter,
whereby the cross-section diameter and length are configured to enable controlled effusion of an outside parylene monomer at 4.6 Pa and 273.14 K through the lumen to the inside of the core deposition chamber based on the unobstructed path, the effusion resulting in a reduced deposition rate compared to outside of the core deposition chamber.

3. The parylene deposition metering apparatus of claim 1 , further comprising:
a plurality of notches along a secant of the conduit at a predetermined axial position of the conduit, each of the plurality of notches corresponding to a different rate of effusion or diffusion and located along the secant based on the rate, thereby enabling a user to more easily cut or sever the conduit to a new, predetermined length.

4. The parylene deposition metering apparatus of claim 1 , wherein the length is less than 40 times the cross-section width for parylene C deposition.

5. The parylene deposition metering apparatus of claim 1 , wherein the cross-section width is greater than 76 μm, and wherein the length is greater than 7 times the cross-section width.

6. The parylene deposition metering apparatus of claim 1 , wherein the core deposition chamber has a volume between 1 cubic centimeter and 10,000 cubic centimeters.

7. The parylene deposition metering apparatus of claim 1 , further comprising a tube that defines the conduit through the top of the cover and that extends through the cover to the outside and inside.

8. The parylene deposition metering apparatus of claim 1 , wherein the cross section of the conduit corresponds to a Knudsen number (Kn) of a monomer between 0.1 and 12.

9. The parylene deposition metering apparatus of claim 1 , wherein the base comprises a rigid, removable tray that is opposite to the cover and that is configured to mate and seal with the base and to retain a substrate inside the core deposition chamber.

10. The parylene deposition metering apparatus of claim 9 , wherein a distance between an inner side of the cover and an inner side of the tray is between 1 centimeter and 40 centimeters.

11. The parylene deposition metering apparatus of claim 1 , wherein the conduit is a first conduit, wherein the cover comprises a plurality of additional conduits, and wherein each additional conduit has substantially a same length and cross-section as the first conduit.

12. The parylene deposition metering apparatus of claim 1 , wherein the cover is disposable after a first predefined number of parylene deposition, wherein the base is disposable after a second predefined number of parylene deposition, and wherein the second predefined number is larger than the first predefined number.

13. The parylene deposition metering apparatus of claim 1 , further comprising a label that identifies at least one of a dimension of the conduit, a pressure differential relative to a pressure inside the core deposition chamber, or an identifier of the core deposition chamber.

14. The parylene deposition metering apparatus of claim 13 , wherein the label comprises a radio frequency identifier-identification (RFID) tag that encodes the at least one of: the dimension, the pressure differential, or the identifier.

15. The parylene deposition metering apparatus of claim 13 , wherein the label comprises a barcode that encodes the at least one of: the dimension, the pressure differential, or the identifier.

16. The parylene deposition metering apparatus of claim 1 , wherein the length is greater than fifteen times the cross-section width.

17. The parylene deposition metering apparatus of claim 1 , wherein each of the distance and the cross-section width is greater than 400 μm, and wherein the length is greater than two times the cross-section width.

18. A parylene deposition system comprising:
a vaporizer configured to vaporize a polymer dimer into a dimeric gas;
a pyrolysis tube connected to the vaporizer and configured to pyrolize the dimeric gas into a monomeric gas;
an outer deposition chamber connected to the pyrolysis tube and having an interior configured to receive the monomeric gas; and
a core deposition chamber placeable in and removable from the outer deposition chamber and configured to effuse the monomeric gas from interior of the outer deposition chamber into an interior of the core deposition chamber, the core deposition chamber comprising:
a base,
a removable cover configured to mate and seal with the base and define the interior of the core deposition chamber, and
a conduit through a top of the cover and about a center of the top of the cover, the conduit defined at least in part by a first fixed portion of the cover and a second fixed portion of the cover, the first fixed portion spaced apart from the second fixed portion by a distance between 50 μm and 6000 μm, the conduit having a lumen connecting the interior of the core deposition chamber to the interior of the outer deposition chamber, the lumen having a length and a cross-section, the cross-section having a width equal or smaller to the distance between the first fixed portion and the second fixed portion of the cover, the length being less than 140 times the cross-section width.

19. The parylene deposition system of claim 18 , further comprising a label reader, wherein the core deposition chamber comprises a label that identifies at least one of: a dimension of the conduit, a pressure differential relative to a pressure inside the core deposition chamber, or an identifier of the core deposition chamber.

20. The parylene deposition system of claim 19 , wherein the system is configured to set a deposition time and a pressure inside the outer deposition chamber based on a read of the label by the label reader.

Assignees

• California Inst Of Techn

Inventors

• Tai Yu-Chong
• Wang Wei
• Kang Dongyang

Classifications

• B05D1/60 Primary

  Deposition of organic layers from vapour phase (vapour phase deposition in general C23C14/00, C23C16/00) · CPC title

• C23C16/45559

  Diffusion of reactive gas to substrate · CPC title

• B81C1/00674

  Treatments for improving wear resistance · CPC title

• B05D3/0493

  using vacuum · CPC title

• B05D3/0486

  Operating the coating or treatment in a controlled atmosphere · CPC title