LOW TEMPERATURE HERMETIC SEALING VIA LASER

• US 20140087099A1
• Filed: 09/27/2012
• Published: 03/27/2014
• Est. Priority Date: 09/27/2012
• Status: Active Grant

• Current Assignee: Guardian Glass LLC (KOCH Industries Incorporated)
• Original Assignee: Guardian Industries Corporation (KOCH Industries Incorporated)
• Inventors: VEERASAMY, Vijayen S., BRACAMONTE, Martin D.
• Granted Patent: US 9,441,416 B2
• Time in Patent Office: Days
• US Class Current: 428/34
• CPC Class Codes: C03C 27/08 with the aid of intervening metal
• CPC Class Codes: C03C 27/10 with the aid of adhesive specially adapted for that purpose
• CPC Class Codes: C03C 8/24 Fusion seal compositions being frit compositions having non-frit additions, i.e. for use as seals between dissimilar materials, e.g. glass and metal; Glass solders
• CPC Class Codes: E06B 3/66 Units comprising two or more parallel glass or like panes permanently secured together reforming and uniting glass sheets by fusing C03B23/00; joining glass to glass or to other materials C03C27/00; laminated glass B32B17/10
• CPC Class Codes: E06B 3/6612 Evacuated glazing units
• CPC Class Codes: E06B 3/66333 of unusual substances, e.g. wood or other fibrous materials, glass or other transparent materials
• CPC Class Codes: E06B 3/66342 characterised by their sealed connection to the panes
• CPC Class Codes: E06B 3/66352 with separate sealing strips between the panes and the spacer
• CPC Class Codes: E06B 3/667 Connectors therefor
• CPC Class Codes: E06B 3/673 Assembling the units E06B3/677 takes precedence ; making hollow glass sheets or bricks C03B23/24
• CPC Class Codes: E06B 3/6733 by applying, e.g. extruding, a ribbon of hardenable material on or between the panes
• CPC Class Codes: E06B 3/67334 by soldering; Preparing the panes therefor
• CPC Class Codes: E06B 3/6775 Evacuating or filling the gap during assembly
• CPC Class Codes: H01L 2224/83896 between electrically insulating surfaces, e.g. oxide or nitride layers
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/12044 OLED
• CPC Class Codes: H01L 2924/1461 MEMS

Abstract

A method and apparatus for low temperature laser sealing of bonded articles is disclosed. Hermetic sealing of glass substrates using low temperature sealing techniques that do not adversely affect bulk strength of glass substrates, the environment created between the substrates and/or any components housed within the sealed glass substrates is disclosed. Such low temperature sealing techniques include use of localized laser heating of sealing materials to form a hermetic seal between glass substrates that does not involve heating the entire article to be sealed.

Claims

1. A vacuum insulated glass (VIG) window unit, comprising:

first and second substantially parallel spaced apart substrates comprising glass that are bonded together by an edge seal, said first and second substrates and said edge seal defining a cavity having a pressure lower than atmospheric pressure; and

wherein said edge seal comprises (i) a metallic or substantially metallic layer; and

(ii) an absorber film.

2. The vacuum insulated glass window unit of claim 1, wherein said absorber film is at least partially diffused into said metallic or substantially metallic layer.

3. The vacuum insulated glass window unit of claim 1, wherein said edge seal comprises first and second absorber films, said first absorber film being located between the first substrate and the metallic or substantially metallic layer, and the second absorber film being located between the second substrate and the metallic or substantially metallic layer.

4. The vacuum insulated glass window unit of claim 1, wherein said absorber film comprises silicon and/or silicon nitride.

5. The vacuum insulated glass window unit of claim 1, wherein said metallic or substantially metallic layer comprises solder.

6. The vacuum insulated glass window unit of claim 1, wherein said absorber film comprises silicon rich silicon nitride characterized by Si_zN_x where z/x is at least 0.78.

7. The vacuum insulated glass window unit of claim 1, wherein said absorber film comprises a first layer comprising silicon nitride and a second layer comprising Ni and/or Cr.

8. A method of making a vacuum insulated glass (VIG) window unit, the method comprising:

providing a first substrate;

applying a seal material to an area of the first substrate to be sealed;

forming a seal by at least;

vitrifying the seal material using laser irradiation, the laser irradiation exposing the seal material but not being directed toward a majority of the first substrate;

bonding the first substrate to a second substrate by continuing to irradiate the vitrified seal material with laser irradiation to melt the seal material; and

evacuating a cavity formed between the first and second substrates and defined by the seal to a pressure lower than atmospheric pressure.

9. The method of claim 8, wherein said first and second substrates comprise glass, and wherein said seal material comprises a glass based frit.

10. The method of claim 9, wherein said glass based frit includes an absorbing dye that absorbs laser energy.

11. The method of claim 8, further comprising:

applying pressure to one or both of the substrates during at least the bonding step, and wherein each of the first and second substrates comprises glass.

12. The method of claim 11, wherein said step of applying pressure includes pumping out the cavity and/or applying pressure via a roller.

13. The method of claim 8, wherein application of said laser irradiation is controlled via a feedback loop.

14. The method of claim 13, wherein the feedback loop includes information regarding a temperature in an area of the laser irradiation.

15. The method of claim 8, wherein the laser irradiation is from one or more of a YVO4 laser, a TI:

Sapphire laser, a Cu vapor laser, an excimer laser, a CO₂ laser, an Nd;

YAG laser, and a harmonic of an Nd;

YAG laser.

16. The method of claim 8, wherein the laser irradiation is pulsed and/or continuous.

17. The method of claim 8, wherein laser irradiation is performed by dual beams directed to opposite sides of the VIG window unit, said dual beams rastering in opposite directions.

18. The method of claim 17, wherein the beams raster at a rate in the range of about 100-150 mm/sec.

19. The method of claim 8, wherein laser irradiation is performed by a single beam rastering in a single direction.

20. The method of claim 8, wherein said seal material comprises a layer comprising metallic or substantially metallic solder.

21. The method of claim 20, wherein an absorber film is interposed between the layer comprising solder and at least one of the substrates.

22. The method of claim 21, wherein laser energy from said laser irradiation is absorbed by said absorber film that in turn heats and melts seal material in the layer comprising solder.

23. The method of claim 21, wherein said absorber film comprises one or more of:

(i) a layer comprising silicon nitride, (ii) Si-rich silicon nitride characterized by Si_zN_x where z/x is at least 0.78; and

(iii) a layer comprising silicon nitride and a layer comprising Ni and/or Cr.

24. The method according to claim 8, further comprising depositing a metal oxide layer on the first and/or second glass substrates prior to applying said seal material.

25. The method of claim 8, further comprising, after said bonding, annealing the seal by laser irradiation.

26. The method of claim 8, wherein application of the laser to the seal material is performed by the laser passing substantially through the first and/or second substrate and irradiating the seal material.

27. The method of claim 8, wherein application of the laser to the seal material is performed from a side so that the laser does not pass through either the first or second substrate of the VIG unit to irradiate the seal material.

28. The method of claim 8, wherein the vitrifying and/or bonding steps are performed (i) in air and/or in an inert atmosphere, and/or (ii) at approximately room temperature.

29. The method of claim 8, further comprising:

providing a thermally conductive heat sink in thermal contact with at least one of the substrates to control lateral heat flow during laser irradiation.

30. A method of making an article including a sealed cavity formed between substrates, the method comprising:

providing first and second substrates comprising glass;

applying a sealing material to at least one of the substrates; and

forming a seal by irradiating the sealing material with a laser, wherein said cavity is defined by geometries of the substrates and the seal.

31. The method of claim 30, further comprising evacuating the cavity to a pressure lower than atmospheric pressure.

32. The method of claim 30, wherein a temperature sensitive component is disposed in said cavity.

33. The method of claim 32, wherein said temperature sensitive component includes at least one of a semiconductor chip, a sensor, an optical component, organic light emitting layers, and/or an OLED.

34. The method of claim 30, wherein said seal is a hermetic seal.

35. The method of claim 30, wherein said seal material comprises a glass based frit, or a layer comprising metallic or substantially metallic solder.

36. The method of claim 30, further comprising annealing the seal via laser irradiation.

37. The method of claim 30, further comprising:

providing a thermally conductive heat sink in thermal contact with at least one of the substrates to control lateral heat flow during laser irradiation.

38. The method of claim 30, wherein application of said laser irradiation is controlled via a feedback loop.

39. The method of claim 38, wherein the feedback loop (a) includes information regarding a temperature in an area of the laser irradiation, and/or (b) is used to control a power and duration of said laser irradiation.