Planarization treatment of pressure sensitive adhesive for rigid-to-rigid substrate lamination

• US 20090186218A1
• Filed: 01/18/2008
• Published: 07/23/2009
• Est. Priority Date: 01/18/2008
• Status: Active Grant

• Current Assignee: Rockwell Collins, Inc. (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Rockwell Collins, Inc. (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Barnidge, Tracy J., Nemeth, Paul R., Sampica, James D., Marzen, Vincent P.
• Granted Patent: US 8,603,288 B2
• Time in Patent Office: Days
• US Class Current: 428/343
• CPC Class Codes: B29C 2043/3233 exerting pressure on mould parts
• CPC Class Codes: B29C 2043/3647 Membranes, diaphragms
• CPC Class Codes: B29C 2043/3649 Inflatable bladders using gas or fluid and related details
• CPC Class Codes: B29C 33/20 Opening, closing or clamping
• CPC Class Codes: B29C 43/12 using bags surrounding the moulding material or using membranes contacting the moulding material
• CPC Class Codes: B29C 43/203 Making multilayered articles
• CPC Class Codes: B29C 43/3642 Bags, bleeder sheets or cauls for isostatic pressing
• CPC Class Codes: B29C 53/18 of plates or sheets
• CPC Class Codes: B29D 7/01 Films or sheets
• CPC Class Codes: B32B 15/08 of synthetic resin
• CPC Class Codes: B32B 2250/05 5 or more layers
• CPC Class Codes: B32B 2250/40 Symmetrical or sandwich layers, e.g. ABA, ABCBA, ABCCBA
• CPC Class Codes: B32B 2255/10 on synthetic resin layer or on natural or synthetic rubber layer
• CPC Class Codes: B32B 2255/26 Polymeric coating
• CPC Class Codes: B32B 2457/00 Electrical equipment
• CPC Class Codes: B32B 2457/08 PCBs, i.e. printed circuit boards
• CPC Class Codes: B32B 2457/202 LCD, i.e. liquid crystal displays
• CPC Class Codes: B32B 2457/206 Organic displays, e.g. OLED
• CPC Class Codes: B32B 2457/208 Touch screens
• CPC Class Codes: B32B 25/08 of synthetic resin
• CPC Class Codes: B32B 27/08 : of synthetic resin
• CPC Class Codes: B32B 27/32 : comprising polyolefins comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30
• CPC Class Codes: B32B 7/12 : using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: Y10T 428/28 : Web or sheet containing structurally defined element or component and having an adhesive outermost layer

Abstract

The present invention is a process for performing a planarization treatment of pressure-sensitive adhesive (PSA). The process includes positioning a first substrate onto a support surface of a planarization tool. The process further includes placing at least one layer of PSA onto the first substrate. The process further includes positioning a second substrate onto the layer(s) of PSA. The process further includes applying a pressure to the second substrate via a flexible membrane, said pressure being applied in a generally uniform, unidirectional and localized manner. Further, the applied pressure flattens the PSA between the first substrate and the second substrate for promoting suitability of the PSA for use in rigid-to-rigid lamination processes.

Claims

1. A system for performing planarization treatment of pressure-sensitive adhesive (PSA), comprising:

a planarization tool, the planarization tool including a support portion and a carriage, the support portion including a support surface configured for supporting at least one PSA block, the carriage having at least one aperture formed therethrough, the carriage configured for being placed upon the support surface, the support portion and the carriage further configured for forming a partial enclosure when the carriage is placed upon the support surface;

a pressurization tool configured with a partial enclosure, the partial enclosure of the pressurization tool having a port configured for connection to a pressurizing source;

a flexible membrane configured for being positioned between the planarization tool and the pressurization tool, the flexible membrane being further configured for sealing the partial enclosure of the pressurization tool to create a first sealed cavity and for sealing the partial enclosure of the planarization tool to create a second sealed cavity when placed between the planarization tool and pressurization tool, the flexible membrane is further configured for applying a pressure created within the first sealed cavity to the at least one PSA block when the first sealed cavity is pressurized,

wherein the carriage of the planarization tool is configured for causing the flexible membrane to apply the pressure to the at least one PSA block in a generally uniform, unidirectional and localized manner, the applied pressure promoting suitability of the PSA for use in rigid-to-rigid lamination processes.

2. A system as claimed in claim 1, wherein the planarization tool is configured with a port, said port configured for being connected to a vacuum pump.

3. A system as claimed in claim 1, wherein the support surface is configured with at least one holder sized for receiving a PSA block included in the at least one PSA block.

4. A system as claimed in claim 3, wherein a holder included in the at least one holder includes a plurality of brackets for securing a position of a PSA block included in the at least one PSA block when the PSA block is received by the holder.

5. A system as claimed in claim 3, wherein an aperture included in the at least one aperture of the carriage is sized for allowing physical access to a PSA block included in the at least one PSA block when the PSA block is positioned within a holder included in the at least one holder.

6. A system as claimed in claim 1, wherein a PSA block included in the at least one PSA block includes a first substrate, at least one layer of PSA, and a second substrate, the at least one layer of PSA being positioned between the first substrate and the second substrate.

7. A system as claimed in claim 1, wherein at least one of the first substrate and the second substrate is a glass plate.

8. A system as claimed in claim 6, wherein the PSA block further includes a first plastic film layer and a second plastic film layer, the first plastic film layer being positioned between the first substrate and the at least one layer of PSA, the second plastic film layer being positioned between the second substrate and the at least one layer of PSA.

9. A system as claimed in claim 2, wherein the pressure created within the first sealed cavity is applied by the flexible membrane to the at least one PSA block while a vacuum is applied within the second sealed cavity via connection of the vacuum pump with the port of the planarization tool.

10. A system as claimed in claim 1, wherein the flexible membrane may be formed of silicone.

11. A system as claimed in claim 1, wherein the flexible membrane may be formed of a material having electrostatic discharge (ESD) properties.

12. A system as claimed in claim 1, wherein the flexible membrane may be formed of an elastic material.

13. A system as claimed in claim 5, further comprising:

a substitute support surface configured for being substituted for the support surface of the planarization tool, the substitute support surface configured with at least one PSA block holder, wherein the PSA block holder(s) of the substitute support surface differ in at least one of size and number from the holder(s) of the support surface.

14. A system as claimed in claim 13, further comprising:

a substitute carriage configured for being substituted for the carriage of the planarization tool, the substitute carriage configured with at least one PSA block access aperture for allowing physical access to PSA block(s) positioned within PSA block holder(s) of the substitute support surface, wherein the PSA block access aperture(s) of the substitute carriage differ in at least one of size and number from the aperture(s) of the carriage.

15. A system as claimed in claim 1, wherein the pressure is a value included in a range of values, the range of values ranging from five (5) pounds per square inch gauge (psig) to two hundred (200) pounds per square inch gauge (psig).

16. A system as claimed in claim 15, wherein the pressure is a value between forty (40) psig and sixty (60) psig.

17. A system as claimed in claim 9, wherein the vacuum is at least one of ten (10) Torr or less than ten (10) Torr.

18. A system as claimed in claim 1, wherein the rigid-to-rigid lamination processes include rigid-to-rigid lamination processes for ruggedization of displays.

19. A system as claimed in claim 1, wherein the pressure applied to the PSA flattens the PSA to at least one of a desired level of flatness and a desired degree of uniformity of flatness for promoting production of visual anomaly-free display assemblies when said PSA is implemented in rigid-to-rigid lamination processes.

20. A system as claimed in claim 6, wherein the first substrate is at least one of cover glass for a Liquid Crystal Display (LCD) or a touch screen, the at least one layer of PSA being pre-adhered to the first substrate prior to being positioned between the first substrate and the second substrate.

21. A process for performing a planarization treatment of pressure-sensitive adhesive (PSA), comprising:

positioning a first substrate onto a support surface of a planarization tool;

placing at least one layer of PSA onto the first substrate;

positioning a second substrate onto the layer(s) of PSA; and

applying a pressure to the second substrate via a flexible membrane, said pressure being applied in a generally uniform, unidirectional and localized manner,

wherein the applied pressure flattens the PSA between the first substrate and the second substrate for promoting suitability of the PSA for use in rigid-to-rigid lamination processes.

22. A process as claimed in claim 21, further comprising:

prior to applying the pressure, positioning a first plastic film layer between the first substrate and the at least one layer of PSA; and

placing a second plastic film layer between the second substrate and the at least one layer of PSA.

23. A process as claimed in claim 21, further comprising:

placing a carriage of the planarization tool onto the support surface prior to applying the pressure, the carriage configured for allowing the applied pressure to be applied to the second substrate in a generally uniform, unidirectional and localized manner.

24. A process as claimed in claim 23, further comprising:

prior to applying the pressure, placing the flexible membrane onto the carriage, the flexible membrane configured for forming a sealed cavity with the planarization tool, said sealed cavity containing the first substrate, the at least one layer of PSA, the second substrate, the first plastic film layer and the second plastic film layer.

25. A process as claimed in claim 24, further comprising:

prior to applying the pressure, connecting the planarization tool to a vacuum pump to create a vacuum within the sealed cavity, thereby applying a vacuum to the first substrate, the at least one layer of PSA, the second substrate, the first plastic film layer and the second plastic film layer.

26. A process as claimed in claim 25, wherein the vacuum and the pressure are concurrently applied to the first substrate, the at least one layer of PSA, the second substrate, the first plastic film layer and the second plastic film layer.

27. A process as claimed in claim 26, wherein the process is performed at ambient temperature.

28. A computer-readable medium having computer-executable instructions for performing a process for performing planarization treatment of pressure-sensitive adhesive (PSA), said process comprising:

positioning a first substrate onto a support surface of a planarization tool;

placing at least one layer of PSA onto the first substrate;

positioning a second substrate onto the layer(s) of PSA; and

applying a pressure to the second substrate via a flexible membrane, said pressure being applied in a generally uniform, unidirectional and localized manner,

wherein the applied pressure flattens the PSA between the first substrate and the second substrate for promoting suitability of the PSA for use in rigid-to-rigid lamination processes.

29. A process for performing a planarization treatment of pressure-sensitive adhesive (PSA), comprising:

positioning a first substrate onto a support surface of a planarization tool, such that a first surface of the first substrate is in contact with the support surface and a second surface of the first substrate, generally opposite the first surface, is oriented away from the support surface, at least one layer of PSA being pre-adhered to the first substrate;

positioning a second substrate onto the layer(s) of PSA; and

applying a pressure to the second substrate via a flexible membrane, said pressure being applied in a generally uniform, unidirectional and localized manner,

wherein the applied pressure flattens the PSA between the first substrate and the second substrate for promoting suitability of the PSA for use in rigid-to-rigid lamination processes.

30. A process as claimed in claim 29, wherein the first substrate is at least one of cover glass for a Liquid Crystal Display (LCD) or a touch screen

31. A pressure-sensitive adhesive (PSA) product for use in rigid-to-rigid lamination processes, the pressure-sensitive adhesive product formed by a planarization process including the steps of:

positioning a first substrate onto a support surface of a planarization tool;

placing at least one layer of PSA onto the first substrate;

positioning a second substrate onto the layer(s) of PSA; and

applying a pressure to the second substrate via a flexible membrane, said pressure being applied in a generally uniform, unidirectional and localized manner, wherein the applied pressure flattens the PSA between the first substrate and the second substrate, the applied pressure, temperature at which the process is performed and duration for which the process is performed being selected for providing a pressure-sensitive adhesive product having at least one of a suitable level of flatness of and a suitable degree of uniformity of flatness for use in rigid-to-rigid lamination processes which provide display assemblies free of visual anomalies.