Attachment of a cap to a substrate-based device with in situ monitoring of bond quality

• US 20140230990A1
• Filed: 02/17/2013
• Published: 08/21/2014
• Est. Priority Date: 02/17/2013
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Invenios LLC (Corning Incorporated)
• Inventors: Karam, Raymond Miller, Roussos, Georges
• Granted Patent: US 9,315,417 B2
• Time in Patent Office: Days
• US Class Current: 156/64
• CPC Class Codes: B29C 65/1635 at least passing through one of the parts to be joined, i.e. laser transmission welding
• CPC Class Codes: B29C 66/112 Single lapped joints
• CPC Class Codes: B29C 66/114 Single butt joints
• CPC Class Codes: B29C 66/53461 joining substantially flat covers and/or substantially flat bottoms to open ends of container bodies
• CPC Class Codes: B29C 66/7465 Glass
• CPC Class Codes: B29C 66/97 Checking completion of joining or correct joining by using indications on at least one of the joined parts
• CPC Class Codes: B29L 2031/3481 Housings or casings incorporating or embedding electric or electronic elements
• CPC Class Codes: C03C 27/00 Joining pieces of glass to pieces of other inorganic material; Joining glass to glass other than by fusing C03C17/00 takes precedence; layered structures comprising at least one glass sheet B32B17/00; wired glass C03B; joining glass to ceramics C04

Abstract

Embodiments generally relate to methods for bonding a cap to a substrate. In one embodiment, the method comprises first providing a ring-cap assembly, comprising a cap and an interposer ring comprising a ring material transparent at an illumination wavelength. A peripheral portion of the ring projects outwards beyond the overlying cap. The portion of the ring bottom surface underlying the projecting peripheral portion of the ring comprises a plurality of downwardly extending fingers. The method further comprises positioning the ring-cap assembly so that the plurality of fingers directly overlies predetermined portions of the substrate top substrate, creating a first bond between a first one of the plurality of fingers and a corresponding first predetermined portion of the substrate top surface, while illuminating and observing the first predetermined portion at the illumination wavelength through the projecting peripheral portion of the ring to determine a quality measure of that first bond.

Claims

1. A method for bonding a cap to a substrate, the method comprising:

providing a ring-cap assembly comprising;

the cap having a cap top surface, a cap bottom surface and being characterized by a cap width; and

an interposer ring comprising a ring material transparent at an illumination wavelength, the ring having a ring top surface, a ring bottom surface, and being characterized by a ring width greater than the cap width, wherein the ring top surface is attached to the cap bottom surface to form the ring-cap assembly such that a peripheral portion of the ring projects outwards beyond the overlying cap, and wherein the portion of the ring bottom surface underlying the projecting peripheral portion of the ring comprises a plurality of downwardly extending fingers;

providing the substrate having a substrate top surface;

positioning the ring-cap assembly so that the plurality of fingers overlies predetermined portions of the substrate top surface; and

creating a first bond between a first one of the plurality of fingers and a corresponding first predetermined portion of the substrate top surface while illuminating and observing the first predetermined portion at the illumination wavelength through the projecting peripheral portion of the ring to determine a quality measure of the first bond.

2. The method of claim 1 further comprising:

if the determined quality measure of the first bond falls below a desired threshold, creating a second bond between a second one of the plurality of fingers and a corresponding second predetermined portion of the substrate top surface while illuminating and observing the second predetermined portion at the illumination wavelength through the projecting peripheral portion of the ring to determine a quality measure of the second bond.

3. The method of claim 1 wherein the observing comprises viewing an optical interference pattern.

4. The method of claim 1 wherein the cap comprises a cap material opaque at the chosen illumination wavelength.

5. The method of claim 1 wherein the ring material is transparent at a chosen range of illumination wavelengths, and wherein creating a first bond between a first one of the plurality of fingers and a corresponding first predetermined portion of the substrate top surface is carried out while illuminating and observing the first predetermined portion at the chosen range of illumination wavelengths through the projecting peripheral portion of the ring to determine a quality measure of the first bond.

6. The method of claim 1 wherein the ring material comprises glass.

7. The method of claim 1 wherein creating a first bond comprises room temperature laser bonding.

8. The method of claim 7 wherein the laser bonding comprises irradiating the first predetermined portion of the substrate surface with a laser beam that reaches the first predetermined portion of the substrate top surface after passing through the interposer ring.

9. The method of claim 7 wherein the laser bonding comprises irradiating the first predetermined portion of the substrate surface with a laser beam that reaches the first predetermined portion of the substrate top surface after passing through the substrate.

10. The method of claim 1 wherein a blocking absorption coating is deposited on either the predetermined portions of the substrate top surface, or the fingers of the interposer ring, or on the predetermined portions of the substrate top surface and the fingers of the interposer ring, prior to the steps of positioning the ring-cap assembly and creating a first bond.

11. The method of claim 1 further comprising:

prior to the step of positioning the ring-cap assembly so that the plurality of fingers overlies predetermined portions of the substrate top surface, positioning the ring-cap assembly and the substrate within a vacuum chamber;

subsequent to the step of positioning the ring-cap assembly so that the plurality of fingers overlies predetermined portions of the substrate top surface, and prior to the step of creating the first bond, clamping the ring-cap assembly and the substrate together and evacuating the vacuum chamber to a first predetermined pressure; and

subsequent to the step of creating the first bond, restoring the vacuum chamber to atmospheric pressure.

12. The method of claim 11 further comprising:

subsequent to the step of clamping the ring-cap assembly and the substrate together and evacuating the chamber to a first predetermined pressure;

filling the vacuum chamber with a predetermined gas to reach a second predetermined pressure.

13. The method of claim 12 wherein the predetermined gas comprises an inert gas.

14. A method for bonding a plurality of caps to a substrate, the method comprising:

providing a plurality of ring-cap assemblies, each ring-cap assembly comprising;

one of the plurality of caps, each cap having a cap top surface, a cap bottom surface and being characterized by a cap width; and

an interposer ring comprising a ring material transparent at an illumination wavelength, the ring having a ring top surface, a ring bottom surface, and being characterized by a ring width greater than the cap width, wherein the ring top surface is attached to the cap bottom surface to form the ring-cap assembly such that a peripheral portion of the ring projects outwards beyond the overlying cap, and wherein the portion of the ring bottom surface underlying the projecting peripheral portion of the ring comprises a plurality of downwardly extending fingers;

providing the substrate having a substrate top surface; and

for each of said plurality of ring-cap assemblies, carrying out the following steps in turn;

first, positioning the assembly so that the plurality of fingers of the first assembly overlies predetermined portions of the substrate top surface; and

second, creating a first bond between a first one of the plurality of fingers of the assembly and a corresponding first predetermined portion of the substrate top surface while illuminating and observing the first predetermined portion at the illumination wavelength through the projecting peripheral portion of the ring to determine a quality measure of the first bond.

15. The method of claim 14 further comprising, for each of said plurality of ring cap assemblies, carrying out a third step following the first positioning step and the second creating step, the third step comprising:

if the determined quality measure of the first bond falls below a desired threshold, creating a second bond between a second one of the plurality of fingers and a corresponding second predetermined portion of the substrate top surface while illuminating and observing the second predetermined portion at the illumination wavelength through the projecting peripheral portion of the ring to determine a quality measure of the second bond.

16. A method for bonding a plurality of caps to a substrate, the method comprising:

providing a plurality of ring-cap assemblies, each ring-cap assembly comprising;

one of the plurality of caps, each cap having a cap top surface, a cap bottom surface and being characterized by a cap width; and

an interposer ring comprising a ring material transparent at an illumination wavelength, the ring having a ring top surface, a ring bottom surface, and being characterized by a ring width greater than the cap width, wherein the ring top surface is attached to the cap bottom surface to form the ring-cap assembly such that a peripheral portion of the ring projects outwards beyond the overlying cap, and wherein the portion of the ring bottom surface underlying the projecting peripheral portion of the ring comprises a plurality of downwardly extending fingers;

providing the substrate having a substrate top surface;

positioning the plurality of assemblies so that the plurality of fingers of each assembly overlies predetermined portions of the substrate top surface; and

creating a plurality of first bonds at substantially the same time, each of said first bonds corresponding to a separate one of said plurality of assemblies,

wherein each of said first bonds is created between a first one of the plurality of fingers of an assembly and a corresponding first predetermined portion of the substrate top surface while illuminating and observing the first predetermined portion at the illumination wavelength through the projecting peripheral portion of the corresponding ring to determine a quality measure of the corresponding first bond.

17. The method of claim 16, further comprising:

prior to the step of positioning the plurality of assemblies so that the plurality of fingers of each assembly overlies predetermined portions of the substrate top surface, positioning the plurality of assemblies and the substrate within a vacuum chamber;

subsequent to the step of positioning the plurality of ring-cap assemblies so that the plurality of fingers of each assembly overlies predetermined portions of the substrate top surface, and prior to the step of creating the plurality of first bonds, clamping the ring-cap assemblies and the substrate together and evacuating the vacuum chamber to a first predetermined pressure; and

subsequent to the step of creating the plurality of first bonds, restoring the vacuum chamber to atmospheric pressure.

18. The method of claim 17, further comprising:

subsequent to the step of clamping the ring-cap assemblies and the substrate together and evacuating the chamber to a first predetermined pressure;

filling the vacuum chamber with a predetermined gas to reach a second predetermined pressure.

19. The method of claim 18 wherein the predetermined gas comprises an inert gas.