Techniques for bonding substrates using an intermediate layer

• US 9,120,287 B2
• Filed: 07/31/2014
• Issued: 09/01/2015
• Est. Priority Date: 12/23/2010
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Ruben, David A, Sandlin, Michael S
• Primary Examiner(s): Ingham, John C
• Application Number:
  US14/447,722
• Publication Number:
  US 20150022983A1
• Time in Patent Office: 397 Days
• US Class Current: 1/1
• CPC Class Codes: B32B 17/06 comprising glass as the main or only constituent of a layer, next to another layer of a specific material
• CPC Class Codes: B32B 2250/02 2 layers
• CPC Class Codes: B32B 2457/00 Electrical equipment
• CPC Class Codes: B32B 7/04 Interconnection of layers
• CPC Class Codes: H01L 21/2007 Bonding of semiconductor wafers to insulating substrates or to semiconducting substrates using an intermediate insulating layer H01L21/2011 takes precedence; bonding of semiconductor wafers to semiconductor wafers for junction formation H01L21/187
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/97 the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 2924/16195 Flat cap [not enclosing an internal cavity]
• CPC Class Codes: H05K 1/0306 Inorganic insulating substrates, e.g. ceramic, glass
• CPC Class Codes: H05K 1/0313 Organic insulating material
• CPC Class Codes: H05K 1/115 Via connections; Lands around holes or via connections H05K1/112 takes precedence
• CPC Class Codes: H05K 1/183 Components mounted in and supported by recessed areas of the printed circuit board
• CPC Class Codes: H05K 2201/0175 Inorganic, non-metallic layer, e.g. resist or dielectric for printed capacitor
• CPC Class Codes: Y10T 428/13 Hollow or container type article [e.g., tube, vase, etc.]
• CPC Class Codes: Y10T 428/24562 Interlaminar spaces
• CPC Class Codes: Y10T 428/265 1 mil or less
• CPC Class Codes: Y10T 428/30 Self-sustaining carbon mass or layer with impregnant or other layer
• CPC Class Codes: Y10T 428/31678 Of metal

Abstract

A method includes depositing a thin film on a first surface of a first substrate and moving a second surface of a second substrate into contact with the thin film such that the thin film is located between the first and second surfaces. The method further includes generating electromagnetic (EM) radiation of a first wavelength, the first wavelength selected such that the thin film absorbs EM radiation at the first wavelength. Additionally, the method includes directing the EM radiation through one of the first and second substrates and onto a region of the thin film until the first and second substrates are fused in the region.

Claims

1. A device comprising:

a first glass substrate;

a second glass substrate; and

an intermediate layer disposed between the first and second glass substrates, wherein the first and second glass substrates are fused together by the intermediate layer, and wherein the intermediate layer is configured to receive a first electromagnetic (EM) radiation through one of the first and second wafers and onto a region of the intermediate layer until the first and second glass substrates are fused in the region without causing the first and second glass substrates to melt or flow.

2. The device of claim 1, wherein the bonding region, as viewed through the first and second glass substrates, is transparent to wavelengths of the first EM radiation in the visible spectrum.

3. The device of claim 1, wherein the bonding region is stronger than the bulk of the first and second glass substrates.

4. The device of claim 1, wherein the first and second glass substrates at least partially define an enclosed cavity, and wherein the bonding region circumscribes the enclosed cavity.

5. The device of claim 4, wherein the bonding region hermetically seals the enclosed cavity from an environment external to the enclosed cavity.

6. The device of claim 4, further comprising an electronic component housed within the enclosed cavity.

7. The device of claim 6, wherein the electronic component includes at least one of an integrated circuit, a sensor, an energy storage device, and an antenna.

8. The device of claim 6, wherein at least one of the first and second glass substrates includes a via that extends from the enclosed cavity to an environment external to the enclosed cavity, and wherein the electronic component is electrically coupled to the via.

9. The device of claim 1, wherein the intermediate layer comprises an amorphous silicon thin film.

10. The device of claim 1, wherein the intermediate layer comprises a metal thin film.

11. The device of claim 1, wherein the first EM radiation is selected having a wavelength that is absorbable by the intermediate layer to cause melting of the intermediate layer.

12. The device of claim 1, wherein the one of the first and second substrates is configured to be transparent to a wavelength of the first EM radiation.

13. The device of claim 1, wherein the first and second substrates include at least one or more cavities.

14. The device of claim 13, further comprising disposing electronic components within the at least one cavity.

15. The device of claim 13, wherein the intermediate layer is deposited to circumscribe the at least one cavity, and the first and second substrates are arranged to be fused in the regions circumscribing the at least one cavity.

16. The device of claim 1, wherein the intermediate layer is configured having a thickness of less than 100 nanometers.

17. The device of claim 1, wherein a region of the intermediate layer is tinted in the visible spectrum prior to directing EM radiation onto the region, and wherein the region is transparent and colorless in the visible spectrum after the first and second substrates are fused in the region.