Methods for hermetically sealing microchip reservoir devices

• US 20030010808A1
• Filed: 06/28/2002
• Published: 01/16/2003
• Est. Priority Date: 06/28/2001
• Status: Active Grant

• Current Assignee: DARE MB Incorporated
• Original Assignee: MicroCHIPS Inc.
• Inventors: Santini, John T. Jr., Uhland, Scott A., Herman, Stephen J., Polito, Benjamin F.
• Granted Patent: US 6,827,250 B2
• Time in Patent Office: Days
• US Class Current: 228/110.1
• CPC Class Codes: A61K 9/0097 Micromachined devices; Microelectromechanical systems [MEMS]; Devices obtained by lithographic treatment of silicon; Devices comprising chips intradermal microneedle arrays A61K9/0021; MEMS in general B81B7/02

Abstract

Methods are provided for hermetically sealing the reservoirs of microchip devices and for hermetically sealing the substrate assemblies in a hermetic packaging structure. In one embodiment, the method comprises (1) providing a primary substrate having a front side and a back side, the substrate comprising a plurality of reservoirs positioned between the front side and the back side, each reservoir being loaded with molecules or a secondary device for controlled release or exposure, the reservoirs having at least one opening in need of sealing, the primary substrate including one or more hermetic sealing materials; (2) providing a hermetic sealing substrate having a surface composed of one or more hermetic sealing materials; (3) positioning the hermetic sealing substrate over the reservoir openings and contacting said hermetic sealing materials of the primary substrate with said hermetic sealing materials of the hermetic sealing substrate; and (4) applying energy or a mechanical force to the contacted sealing materials effective to form a hermetic seal between the hermetic sealing substrate and the primary substrate to hermetically seal the reservoir openings.

Claims

1. A method for hermetically sealing reservoirs of a microchip device, the method comprising:

providing a primary substrate having a front side and a back side, the substrate comprising a plurality of reservoirs positioned between the front side and the back side, each reservoir being loaded with molecules or a secondary device for controlled release or exposure, the reservoirs having at least one opening in need of sealing, the primary substrate including one or more hermetic sealing materials;

providing a hermetic sealing substrate having a surface composed of one or more hermetic sealing materials;

positioning the hermetic sealing substrate over the reservoir openings and contacting said hermetic sealing materials of the primary substrate with said hermetic sealing materials of the hermetic sealing substrate; and

applying energy or a mechanical force to the contacted sealing materials effective to form a hermetic seal between the hermetic sealing substrate and the primary substrate to hermetically seal the reservoir openings.

2. The method of claim 1, wherein the energy is applied through a welding process.

3. The method of claim 2, wherein the welding process comprises ultrasonic welding.

4. The method of claim 2, wherein the welding process comprising laser welding.

5. The method of claim 1, wherein the energy is applied by heating to cause a reaction between the hermetic sealing materials of the primary substrate and the hermetic sealing materials of the hermetic sealing substrate.

6. The method of claim 5, wherein the reaction is a eutectic reaction.

7. The method of claim 6, wherein the eutectic reaction forms a eutectic bond comprising a eutectic composition selected from the group consisting of gold/silicon, gold/germanium, gold/tin, gold/indium, lead/tin, lead/indium, and platinium/silicon.

8. The method of claim 5, wherein the heating comprises resistive heating using a patterned resistor.

9. The method of claim 1, wherein the hermetic sealing material of the hermetic sealing substrate comprises a metal gasket and a compressive force is applied effective to deform the metal gasket around each reservoir opening.

10. The method of claim 9, further comprising tapered structures extending from the primary substrate surface and effective to concentrate the compressive forces at areas around the reservoir opening.

11. The method of claim 1, wherein the hermetic sealing substrate comprises a metal film or metal foil.

12. The method of claim 1, wherein the hermetic sealing materials of the primary substrate, of the sealing substrate, or both, comprise a silicate glass.

13. The method of claim 1, wherein the hermetic sealing materials of the primary substrate, of the sealing substrate, or both, comprise a metal selected from the group consisting of gold, platinum, titanium, palladium, tantalum, aluminum, and stainless steel.

14. The method of claim 1, wherein the primary substrate comprises a hermetic material selected from the group consisting of ceramics, metals, silicon, or glasses.

15. The method of claim 1, wherein, following formation of the hermetic seal, the hermetic sealing substrate is a reservoir cap which can selectively be disintegrated to release or expose the molecules or secondary device.

16. The method of claim 15, wherein the front side of the substrate comprises metal traces and the hermetic sealing substrate is welded onto the metal traces.

17. The method of claim 1, wherein the reservoir is closed, at the end distal the opening in need of sealing, by a reservoir cap which can selectively be disintegrated to release or expose the molecules or secondary device.

18. The method of claim 1, wherein the reservoirs contain drug molecules.

19. The method of claim 1, further comprising applying a protective coating material over the hermetic sealing substrate, on a surface distal the surface that contacts the hermetic sealing materials of the primary substrate, before or after the reservoirs are hermetically sealed.

20. The method of claim 1, wherein hermetic sealing substrate is a multi-layered structure comprising a glass layer which is anodically bonded to the primary substrate, the glass layer having apertures in communication with the reservoirs.

21. The method of claim 20, wherein the multi-layered structure further comprises a patterned metal layer which is anodically or eutectically bonded to the glass layer on the side distal the primary substrate, the patterned metal layer having apertures in communication with the reservoirs and with the apertures in the glass layer.

22. The method of claim 21, wherein the multi-layered structure further comprises a metal foil which is laser welded to the patterned metal layer on the side distal the glass layer, the metal sheet sealing the space defined by the reservoirs and apertures.

23. A microchip device sealed by the method of claim 1.

25. The method of claim 24, wherein the forming step comprises laser welding, ultrasonic welding, or both.

26. The method of claim 24, wherein the forming step comprises electroplating a metal across an interface between a surface of the substrate and a surface of the packaging structure.

27. The method of claim 24, wherein the hermetic seal comprises a eutectic bond.

28. The method of claim 24, wherein the packaging structure comprises two metal pieces which are laser welded together after encasing the substrate between portions of the two pieces.

29. The method of claim 24, wherein the packaging structure further comprises power sources, control electronics, or a combination thereof, for powering disintegration of the reservoir caps, controlling the activation time of for disintegration of the reservoir caps, or both.

24. A method of packaging an active-release microchip device, comprising:

providing a microchip device having a substrate, a plurality of reservoirs containing contents for release or exposure, and reservoir caps over the reservoir contents;

providing a hermetic packaging structure; and

forming a hermetic seal between the substrate of the microchip device and one or more surfaces of the packaging structure, effective to encase the microchip device yet leave the reservoir caps exposed and operational.

30. A microchip device package as made by claim 24.