Packaging and assembly method for optical coupling

• US 6,512,861 B2
• Filed: 06/26/2001
• Issued: 01/28/2003
• Est. Priority Date: 06/26/2001
• Status: Expired due to Term

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Intel Corporation
• Inventors: Ahadian, Joseph F., Swan, Johanna Marie, Young, Ian A., Chakravorty, Kishore K.
• Primary Examiner(s): PATEL, TULSIDAS C
• Application Number:
  US09/892,921
• Publication Number:
  US 20020196997A1
• Time in Patent Office: 581 Days
• Field of Search: 385/14, 385/32, 385/33, 385/35, 385/36
• US Class Current: 385/14
• CPC Class Codes: G02B 6/42 Coupling light guides with opto-electronic elements
• CPC Class Codes: G02B 6/4206 Optical features G02B6/4207, G02B6/421 take precedence
• CPC Class Codes: G02B 6/4212 the intermediate optical element being a coupling medium interposed therebetween, e.g. epoxy resin, refractive index matching material, index grease, matching liquid or gel
• CPC Class Codes: G02B 6/4214 the intermediate optical element having redirecting reflective means, e.g. mirrors, prisms for deflecting the radiation from horizontal to down- or upward direction toward a device G02B6/4246 takes precedence
• CPC Class Codes: G02B 6/4231 with intermediate elements, e.g. rods and balls, between the elements
• CPC Class Codes: G02B 6/43 Arrangements comprising a plurality of opto-electronic elements and associated optical interconnections
• CPC Class Codes: H05K 1/0274 Optical details, e.g. printed circuits comprising integral optical means H05K1/0269 takes precedence; coupling light guides with opto-electronic components G02B6/42
• CPC Class Codes: H05K 2201/10121 Optical component, e.g. opto-electronic component
• CPC Class Codes: H05K 2201/10734 Ball grid array [BGA]; Bump grid array
• CPC Class Codes: H05K 3/3436 having an array of bottom contacts, e.g. pad grid array or ball grid array components

Abstract

A package allowing both electrical and optical coupling between one or more integrated circuits and a printed circuit board (PCB) has optical waveguide structures in addition to electrical connections. An optically active device may be flip-bonded directly to an integrated circuit using solder bump technology. The integrated circuit then flip-bonded or wire-bonded to a BGA package. The package has alignment rails or balls and V-grooves to anchor the alignment rails/balls to align the BGA package to the PCB. The BGA package is bonded to the PCB using solder reflow technology.

Claims

1. An apparatus, comprising:

a substrate having a plurality of connection means disposed on an underside thereof and an aperture defined therethrough;

an integrated circuit having an underside flip-bonded to a topside of the substrate; and

an optically active device flip-bonded to the underside of the integrated circuit to generate or receive an optical signal passing through the aperture in the substrate.

2. The apparatus of claim 1 wherein the apparatus comprises a Ball Grid Array package, and the plurality of connection means comprise a plurality of solder balls.

3. The apparatus of claim 1 wherein the optical device is a vertical cavity surface emitting laser (VCSEL), light emitting diode (LED), photodetector, or optical modulator.

4. The apparatus of claim 1 wherein the optically active device is flip-bonded to the integrated circuit using solder bumps.

5. The apparatus of claim 1 wherein the optically active device is flip-bonded to the integrated circuit using solder reflow technology.

6. The apparatus of claim 1 wherein the integrated circuit comprises one of an optical device driver, a transimpedance amplifier, a microprocessor, a microprocessor chip set, a networking integrated circuit, or a memory.

7. The apparatus of claim 1, further comprising a printed circuit board (PCB) operatively coupled to the underside of the substrate via the plurality of connection means.

8. The apparatus of claim 7 wherein the PCB includes a waveguide to steer light to or from the optically active device.

9. The apparatus of claim 7 wherein one of the PCB and the substrate include alignment grooves, and the other of the PCB and substrate include alignment balls, said alignment grooves and alignment balls used to align the substrate with the PCB.

10. The apparatus of claim 8 wherein the waveguide is faceted forty-five degrees to steer light to or from the optically active device.

11. The apparatus of claim 9, wherein the PCB is flip-bonded to the substrate using solder reflow technology, wherein the PCB is initially aligned with the substrate using the alignment grooves and alignment balls, and wherein during a solder reflow operation the surface tension on the solder pulls the substrate into alignment with the PCB.

12. The apparatus of claim 2, wherein the Ball Grid Array package is flip-mounted to a printed circuit board (PCB) including an optical waveguide and the optically active device is optically coupled to the optical waveguide.

13. An apparatus, comprising:

a substrate having a plurality of connection means disposed on an underside thereof and an optical via defined therethrough;

an optically active device flip-bonded to a topside of the substrate and positioned to receive or emit an optical signal via the optical via; and

an integrated circuit flip-bonded to the topside of the substrate next to the optically active device.

14. The apparatus of claim 13 wherein the optical via is filled with an underfill polymer having an index of refraction less than the index of refraction of the substrate surrounding the optical via.

15. The apparatus of claim 13 wherein the optical via is filled with a substrate laminate polymer having an index of refraction less than the index of refraction of the substrate surrounding the optical via.

16. The apparatus of claim 13 wherein the optical via is terminated by a lens.

17. The apparatus of claim 13, further comprising a printed circuit board (PCB) operatively coupled to the underside of the substrate via the plurality of connection means.

18. The apparatus of claim 17 wherein the PCB includes a waveguide to steer light to or from the optically active device.

19. The apparatus of claim 17 wherein one of the PCB and the substrate include alignment grooves, and the other of the PCB and substrate include alignment balls, said alignment grooves and alignment balls used to align the substrate with the PCB.

20. The apparatus of claim 18 wherein the waveguide is faceted forty-five degrees to steer light to or from the optically active device.

21. The apparatus of claim 19, wherein the PCB is flip-bonded to the substrate using solder reflow technology, wherein the PCB is initially aligned with the substrate using the alignment grooves and alignment balls, and wherein during a solder reflow operation the surface tension on the solder pulls the substrate into alignment with the PCB.

22. The apparatus of claim 13 wherein the apparatus comprises a Ball Grid Array package, and the plurality of connection means comprise a plurality of solder balls.

23. An apparatus, comprising:

a substrate having a plurality of connection means disposed on an underside thereof;

an integrated circuit wire-bonded to the underside of the substrate; and

an optically active device flip-bonded to the integrated circuit.

24. The apparatus of claim 23, further comprising a printed circuit board (PCB) operatively coupled to the substrate via the plurality of connection means.

25. The apparatus of claim 24 wherein the PCB includes a waveguide to steer light to or from the optically active device.

26. The apparatus of claim 24 wherein one of the PCB and the substrate include alignment grooves, and the other of the PCB and substrate include alignment balls, said alignment grooves and alignment balls used to align the substrate with the PCB.

27. The apparatus of claim 25 wherein the waveguide is faceted forty-five degrees to steer light to or from the optically active device.

28. The apparatus of claim 26, wherein the PCB is flip-bonded to the substrate using solder reflow technology, wherein the PCB is initially aligned with the substrate using the alignment grooves and alignment balls, and wherein during a solder reflow operation surface tension on the solder pulls the substrate into alignment with the PCB.

29. A method, comprising:

flip-bonding an optically active device to an integrated circuit;

aligning the optically active device to a clearance in a substrate; and

flip-bonding the integrated circuit to the substrate.

30. The method of claim 29, further comprising flip-bonding the substrate to a printed circuit board using solder mount technology or solder reflow technology.

31. The method of claim 30, further comprising aligning the substrate to a printed circuit board using alignment balls and alignment grooves.

32. The method of claim 29, wherein the substrate includes a plurality of connection means disposed on an underside thereof, the method further comprising encapsulating the integrated circuit to form a packaged component.

33. A method, comprising:

aligning an optically active device to a clearance in a substrate;

flip-bonding the optically active device to the substrate; and

flip-bonding an integrated circuit to the substrate next to the optically active device.

34. The method of claim 33, further comprising aligning the optically active device to a clearance in the substrate using solder bumps.

35. The method of claim 33, further comprising flip-bonding the substrate to a printed circuit board (PCB) using solder mount technology or solder reflow technology.

36. The method of claim 35, further comprising aligning the substrate to the PCB using alignment balls and alignment grooves.

37. The method of claim 33, wherein the substrate includes a plurality of connection means disposed on an underside thereof, the method further comprising encapsulating the integrated circuit and optical active device to form a packaged component.

38. A method, comprising:

flip-bonding an optically active device to an integrated circuit; and

wire-bonding the integrated circuit to an underside of a substrate having a plurality of connection means disposed on the underside thereof; and

encapsulating the optically active device and the integrated circuit to form a packaged component including an optical via disposed on the underside of the packaged component to enable light signals to be emitted from or received by the optically active device.

39. The method of claim 38, further comprising flip-bonding the substrate to a printed circuit board (PCB) using solder mount technology or solder reflow technology.

40. The method of claim 39, further comprising aligning the substrate to the PCB using alignment balls and alignment grooves.

41. A method, comprising:

drilling an optical via in a substrate;

filling the optical via with an underfill polymer;

grinding excess underfill polymer;

aligning an optically active device to the optical via;

flip-bonding the optically active device to the substrate; and

flip-bonding an integrated circuit to the substrate next to the optically active device.

42. The method of claim 41, further comprising terminating the optical via using a focusing element.

43. The method of claim 42, wherein the focusing element is a lens.