Methods and apparatuses for casting polymer products

Patent metadata

Field	Value
Publication number	US-11787138-B2
Application number	US-202217725171-A
Country	US
Kind code	B2
Filing date	Apr 20, 2022
Priority date	Oct 17, 2017
Publication date	Oct 17, 2023
Grant date	Oct 17, 2023

Abstract

An example system for molding a photocurable material into a planar object includes a first mold structure having a first mold surface, a second mold structure having a second mold surface, and one or more protrusions disposed along at least one of the first mold surface or the second mold surface. During operation, the system is configured to position the first and second mold structures such that the first and second mold surfaces face each other with the one or more protrusions contacting the opposite mold surface, and a volume having a total thickness variation (TTV) of 500 nm or less is defined between the first and second mold surfaces. The system is further configured to receive the photocurable material in the volume, and direct radiation at the one or more wavelengths into the volume.

First claim

What is claimed is:

1. A system for molding a photocurable material into a planar object, the system comprising:
a first mold structure;
a second mold structure;
a plurality of protrusions disposed on at least one of the first mold structure or the second mold structure; and
a plurality of linear slots defined on at least one of the first mold structure or the second mold structure,
wherein a first slot of the plurality of slots extends in a first direction, wherein a second slot of the plurality of slots extends in a second direction, and wherein the first direction is not parallel to the second direction, and
wherein the system is configured, during operation, to produce a polymer film by performing operations comprising:
positioning the first and second mold structures such that:
at least some of the plurality of protrusions insert into at least some of the plurality of linear slots, and
a gap is defined at least in part by the first mold structure and the second mold structure, the gap corresponding to a shape of the polymer film,

receiving the photocurable material in the gap, and

directing radiation at the one or more wavelengths into the gap to harden the photocurable material into the polymer film.

2. The system of claim 1 , wherein at least one of the first mold structure or the second mold structure is substantially transparent to the radiation.

3. The system of claim 1 , wherein the plurality of protrusions comprises a first protrusion configured to insert into the first slot, and wherein a cross-sectional area of the first slot is larger than a cross-sectional area of the first protrusion.

4. The system of claim 3 , wherein the plurality of protrusions comprises a second protrusion configured to insert into the second slot, and wherein a cross-sectional area of the second slot is larger than a cross-sectional area of the second protrusion.

5. The system of claim 1 , wherein the plurality of slots comprises a third slot extending in a third direction, and wherein the third direction is not parallel to the first direction or the second direction.

6. The system of claim 1 , wherein at least one of the plurality of protrusions has a rectangular cross-section.

7. The system of claim 1 , wherein the system comprises:
a platform,
a bridge extending between the platform and at least one of the first mold structure or the second mold structure, wherein a width of the platform is greater than a width of the bridge, and
a fiducial feature disposed on the platform.

8. The system of claim 7 , wherein the fiducial feature comprises at least one of a structural pattern or a marking.

9. The system of claim 7 , further comprising:
a spacer structure disposed on the platform.

10. The system of claim 1 , further comprising a structural pattern defined on at least one of the first mold structure or the second mold structure.

11. The system of claim 10 , wherein the structural pattern comprises an etched grating pattern.

12. The system of claim 10 , wherein the structural pattern comprises a plurality of additional protrusions and a plurality of channels,
wherein a height of each of the additional protrusions is between 1 μm and 10 μm.

13. The system of claim 12 , wherein a width of each of the additional protrusions is between 50 μm and 200 μm.

14. The system of claim 12 , wherein the structural pattern comprises a hydrophobic nanostructure.

15. The system of claim 14 , wherein the hydrophobic nanostructure comprises at least one of organically modified silica, polydimethylsiloxane, fluoro-silane, or polytetrafluoroethylene.

16. The system of claim 10 , wherein the structural pattern is configured to impede a flow of the photocurable material across at least one of the first mold structure or the second mold structure.

17. The system of claim 16 , wherein a volume of the structural pattern is greater than a difference between (i) a volume of the photocurable material and (ii) a volume of the gap.

18. The system of claim 10 , wherein the structural pattern is configured to impart a corresponding pattern on an edge of the polymer film.

19. The system of claim 1 , further comprising one or more heating elements, and
wherein the operations comprise applying heat to the photocurable material in the gap using the one or more heating elements.

20. The system of claim 1 , wherein, during operation, the system is configured to position the first mold structure and the second mold structure such that the gap has a thickness between 20 μm and 2 mm.

Assignees

• Magic Leap Inc

Inventors

• Chang Chieh
• Peroz Christophe
• Bhagat Sharad D
• Patterson Roy Matthew
• Klug Michael Anthony
• Carden Charles Scott

Classifications

• B29C2033/0005

  with transparent parts, e.g. permitting visual inspection of the interior of the cavity · CPC title

• B29D7/01

  Films or sheets · CPC title

• B29C33/40

  Plastics, e.g. foam or rubber · CPC title

• B29C35/0805

  using electromagnetic radiation · CPC title

• B29C39/02

  for making articles of definite length, i.e. discrete articles · CPC title