Microelectronic imagers having front side contacts

• US 7,646,075 B2
• Filed: 07/07/2005
• Issued: 01/12/2010
• Est. Priority Date: 08/31/2004
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Akram, Salman
• Primary Examiner(s): Rose; Kiesha L.
• Assistant Examiner(s): WRIGHT, TUCKER J
• Application Number:
  US11/177,905
• Publication Number:
  US 20060044433A1
• Time in Patent Office: 1,650 Days
• Field of Search: 257431-435, 257/E31.054, 257/E23.194, 438/64, 438/66, 438/67
• US Class Current: 257/434
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 27/14618 Containers
• CPC Class Codes: H01L 27/14625 Optical elements or arrangements associated with the device
• CPC Class Codes: H01L 27/14685 Process for coatings or optical elements
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 31/0203 Containers; Encapsulations , e.g. encapsulation of photodiodesfor photovoltaic devices H01L31/048; for organic photosensitive devices H10K30/80
• CPC Class Codes: H04N 23/54 Mounting of pick-up tubes, electronic image sensors, deviation or focusing coils
• CPC Class Codes: H04N 23/55 Optical parts specially adapted for electronic image sensors; Mounting thereof

Abstract

Microelectronic imager assemblies with front side contacts and methods for fabricating such microelectronic imager assemblies are disclosed herein. In one embodiment, a microelectronic imager assembly comprises a workpiece including a substrate having a front side and a backside. The assembly further includes a plurality of imaging dies on and/or in the substrate. The imaging dies include image sensors at the front side of the substrate, integrated circuitry operatively coupled to the image sensors, and bond-pads at the front side of the substrate electrically coupled to the integrated circuitry. The assembly also includes a plurality of stand-offs at the front side of the substrate. The stand-offs have apertures aligned with corresponding image sensors. The assembly further includes a plurality of external contacts electrically coupled to corresponding bond-pads and projecting away from the dies.

Claims

1. A microelectronic imager assembly, comprising:

a workpiece comprising;

a substrate including a front side and a backside; and

a plurality of imaging dies formed at least partially within the substrate, the imaging dies comprising image sensors at the front side of the substrate, integrated circuitry operatively coupled to the image sensors, and bond-pads at the front side of the substrate electrically coupled to the integrated circuitry;

a plurality of stand-offs, each stand-off comprising a front side and a back side, the back side being in contact with the front side of the substrate, the stand-offs having apertures aligned with corresponding image sensors; and

a plurality of external contacts terminating at the front side of the stand-offs and electrically coupled at the front side of the substrate to corresponding bond-pads of the imaging dies.

2. The assembly of claim 1 wherein the plurality of external contacts comprises a plurality of interconnects extending through the stand-offs and electrically coupled to corresponding bond-pads.

3. The assembly of claim 1 wherein the plurality of external contacts comprises a plurality of connectors electrically coupled to corresponding bond-pads.

4. The assembly of claim 1 wherein:

the plurality of external contacts comprise a plurality of interconnects extending through the stand-offs and electrically coupled to corresponding bond-pads, the interconnects including first end portions electrically coupled to the bond-pads and second end portions spaced apart from the first end portions; and

the assembly further comprises a plurality of connectors electrically coupled to the second end portions of the interconnects.

5. The assembly of claim 1, further comprising a plurality of covers over corresponding image sensors, the individual covers being supported by the stand-offs at corresponding dies and transmissive to a desired radiation for the image sensors.

6. The assembly of claim 5 wherein the covers further comprise a curved surface to direct the radiation.

7. The assembly of claim 1 wherein:

the stand-offs comprise steps and sidewalls defining interface features; and

the imager assembly further comprises covers over corresponding image sensors, the individual covers being seated with the interface features at corresponding dies and transmissive to a desired radiation for the image sensors.

8. The assembly of claim 1 wherein:

the stand-offs comprise first mounting sites having first steps and second mounting sites having second steps; and

the imager assembly further comprises (a) covers over corresponding image sensors, the individual covers being seated with first steps at corresponding dies, and (b) optical devices including second substrates seated with second steps and optics elements on and/or in the second substrates aligned with corresponding image sensors.

9. The assembly of claim 1, further comprising a plurality of optical devices attached to the stand-offs and/or the substrate, the optical devices having optics elements positioned at a desired location relative to corresponding image sensors.

10. The assembly of claim 1, further comprising a plurality of optical devices attached to the stand-offs and/or the substrate, and wherein the optical devices include focus lenses, dispersion lenses, pin-hole lenses, filters, and/or anti-reflective films.

11. The assembly of claim 1, further comprising a plurality of trenches between individual image sensors, the individual trenches extending into the front side of the substrate an intermediate depth.

12. The assembly of claim 1 wherein the stand-offs comprise a three-dimensional stereolithography material, an epoxy, and/or a UV curable material.

13. A microelectronic imaging unit, comprising:

a microelectronic die having a front side and a backside, an image sensor formed within the front side, an integrated circuit electrically coupled to the image sensor, and a plurality of bond-pads at the front side electrically coupled to the integrated circuit;

a stand-off projecting from the die and having an opening aligned with the image sensor, the stand-off comprising a front side and a back side, the back side of the stand-off being in contact with the front side of the die; and

a plurality of external contacts terminating at the front side of the stand-off and operatively coupled at the front side of the substrate to corresponding bond-pads of the microelectronic die.

14. The imaging unit of claim 13 wherein the plurality of external contacts comprises a plurality of interconnects extending through the stand-off and electrically coupled to corresponding bond-pads.

15. The imaging unit of claim 13 wherein the plurality of external contacts comprises a plurality of connectors electrically coupled to corresponding bond-pads.

16. The imaging unit of claim 13 wherein:

the plurality of external contacts comprise a plurality of interconnects extending through the stand-off and electrically coupled to corresponding bond-pads, the interconnects including first end portions electrically coupled to the bond-pads and second end portions spaced apart from the front side of the die; and

the imaging unit further comprises a plurality of connectors electrically coupled to the second end portions of the interconnects.

17. The imaging unit of claim 13, further comprising a cover over the image sensor and engaged with the stand-off, the cover being transmissive to radiation for the image sensor.

18. The imaging unit of claim 17 wherein the cover further comprises a curved surface to direct the radiation.

19. The imaging unit of claim 13 wherein:

the stand-off comprises a step and a sidewall defining an interface feature, and

the imaging unit further comprises an optical device having a substrate and an optics element on and/or in the substrate, the optical device being seated with the interface feature to position the optics element at a desired location relative to the image sensor.

20. The imaging unit of claim 13 wherein the stand-off comprises a first mounting site having a first step and a second mounting site having a second step, and wherein the imaging unit further comprises:

a cover over the image sensor and seated with the first step, the cover being transmissive to radiation for the image sensor; and

an optical device having an optics element seated with the second step to position the optics element at a desired location relative to the image sensor.

21. The imaging unit of claim 13 wherein the stand-off comprises (a) a first mounting site having a first alignment and a first stop component, the first alignment component being at a preset lateral location from the image sensor and the first stop component being at a fixed preset elevation from the image sensor, and (b) a second mounting site having a second alignment component and a second stop component, the second alignment component being at a preset lateral location from the image sensor and the second stop component being at a fixed preset elevation from the image sensor, and wherein the imaging unit further comprises:

a cover over the image sensor and engaged with the first alignment component and the first stop component, the cover being transmissive to radiation for the image sensor; and

an optical device having an optics element engaged with the second alignment component and the second stop component to position the optics element at a desired location relative to the image sensor.

22. The imaging unit of claim 13, further comprising an optical device attached to the stand-off and/or the die, the optical device having a substrate with an optics element on and/or in the substrate positioned at a desired location relative to the image sensor.

23. The imaging unit of claim 13, further comprising an optical device attached to the stand-off and/or the die, the optical device including a focus lens, a dispersion lens, a pin-hole lens, a filter, and/or an anti-reflective film.

24. The imaging unit of claim 13 wherein:

the plurality of external contacts comprise a plurality of interconnects extending through the stand-off and electrically coupled to corresponding bond-pads; and

the imaging unit further comprises a support member including an opening through the support member and a plurality of contacts proximate the opening, and wherein the image sensor is aligned with the opening and the interconnects are electrically coupled to corresponding contacts on the support member.

25. The imaging unit of claim 13 wherein:

the plurality of external contacts comprise a plurality of connectors electrically coupled to corresponding bond-pads; and

the imaging unit further comprises a support member including an opening through the support member and a plurality of contacts proximate the opening, and wherein the image sensor is aligned with the opening and the connectors are electrically coupled to corresponding contacts on the interposer substrate.

26. The imaging unit of claim 13 wherein the stand-off comprises a three-dimensional stereolithography material, an epoxy, and/or a UV curable material.

27. A microelectronic imager assembly, comprising:

a workpiece comprising;

a substrate having a front side and a backside; and

a plurality of imaging dies formed at least partially within the substrate, the imaging dies comprising image sensors at the front side of the substrate, integrated circuitry operatively coupled to the image sensors, and bond-pads at the front side of the substrate electrically coupled to the integrated circuitry;

a plurality of stand-offs, each stand-off comprising a front side and a back side, the back side being in contact with the front side of the substrate, the stand-offs having apertures aligned with corresponding image sensors; and

a plurality of interconnects terminating at the front side of the stand-offs, the interconnects extending through the stand-offs and being electrically coupled at the front side of the substrate to corresponding bond-pads of the imaging dies.

28. The assembly of claim 27 wherein:

the stand-offs includes passages extending completely through the stand-offs and aligned with corresponding bond-pads; and

the interconnects comprise a conductive fill material disposed in the passages and electrically coupled to corresponding bond-pads.

29. The assembly of claim 27 wherein, further comprising a plurality of covers over corresponding image sensors, the individual covers being supported by the stand-offs at corresponding dies and transmissive to a desired radiation for the image sensors.

30. The assembly of claim 27 wherein:

the plurality of interconnects include first end portions electrically coupled to the bond-pads and second end portions spaced apart from the front side of the die; and

the assembly further comprises a plurality of connectors electrically coupled to the second end portions of the interconnects.

31. The assembly of claim 27 wherein the stand-offs comprise first mounting sites having first steps and second mounting sites having second steps, and wherein the assembly further comprises:

a plurality of covers over the image sensors and seated with the first steps, the covers being transmissive to radiation for the corresponding image sensors; and

optical devices having optics elements seated with the second steps to position the optics elements at a desired location relative to corresponding image sensors.

32. The assembly of claim 27 wherein the individual stand-offs comprise (a) a first mounting site having a first alignment and a first stop component, the first alignment component being at a preset lateral location from one of the image sensors and the first stop component being at a fixed preset elevation from the one image sensor, and (b) a second mounting site having a second alignment component and a second stop component, the second alignment component being at a preset lateral location from the one image sensor and the second stop component being at a fixed preset elevation from the one image sensor, and wherein the assembly further comprises:

a plurality of covers over the image sensors and engaged with the first alignment components and the first stop components, the covers being transmissive to -radiation for the corresponding image sensors; and

optical devices having optics element engaged with the second alignment components and second stop components to position the optics elements at a desired location relative to corresponding image sensors.

33. The assembly of claim 27, further comprising optical devices attached to the stand-offs and/or the substrate, the optical devices including focus lenses, dispersion lenses, pin-hole lenses, filters, and/or anti-reflective films.

34. The assembly of claim 27, further comprising a plurality of trenches between individual image sensors, the trenches extending into the front side of the substrate an intermediate depth.

35. The assembly of claim 27 wherein the stand-offs comprise a three-dimensional stereolithography material, an epoxy, and/or a UV curable material.

36. A microelectronic imager assembly, comprising:

a workpiece comprising;

a substrate including a front side and a backside; and

a plurality of imaging dies formed at least partially within the substrate, the imaging dies comprising image sensors at the front side of the substrate, integrated circuitry operatively coupled to the image sensors, and bond-pads at the front side of the substrate electrically coupled to the integrated circuitry;

a plurality of stand-offs, each stand-off comprising a front side and a back side, the back side being in contact with the front side of the substrate, the stand-offs having apertures aligned with corresponding image sensors; and

a plurality of interconnects terminating at the front side of the stand-offs, the interconnects extending through the stand-offs and being electrically coupled at the front side of the substrate to corresponding bond-pads of the imaging dies;

a plurality of covers over corresponding image sensors, the individual covers being supported by the stand-offs at corresponding dies and transmissive to a desired radiation for the image sensors; and

optical devices attached to the stand-offs and/or the covers, the individual optical devices including a substrate with an optics element on and/or in the substrate at a desired location relative to one of the image sensors, wherein the optical devices include focus lenses, dispersion lenses, pin-hole lenses, filters, and/or anti-reflective films.

37. The assembly of claim 36 wherein:

the stand-offs includes passages extending completely through the stand-offs and aligned with corresponding bond-pads; and

the interconnects comprise a conductive fill material in the passages and electrically coupled to corresponding bond-pads.

38. The assembly of claim 36 wherein:

the plurality of interconnects include first end portions electrically coupled to the bond-pads and second end portions spaced apart from the front side of the substrate; and

the assembly further comprises a plurality of connectors electrically coupled to the second end portions of the interconnects.

39. The assembly of claim 36 wherein:

the stand-offs comprise first mounting sites having first steps and second mounting sites having second steps;

the covers are seated with the first steps; and

the optical devices are seated with the second steps to position the optics elements at a desired location relative to the image sensor.

40. The assembly of claim 36 wherein:

the individual stand-offs comprise (a) a first mounting site having a first alignment and a first stop component, the first alignment component being at a preset lateral location from the image sensor and the first stop component being at a fixed preset elevation from the image sensor, and (b) a second mounting site having a second alignment component and a second stop component, the second alignment component being at a preset lateral location from the image sensor and the second stop component being at a fixed preset elevation from the image sensor;

the covers are engaged with first alignment components and the first stop components; and

the optical devices are engaged with the second alignment components and the second stop components to position the optics elements at a desired location relative to the corresponding image sensors.

41. The assembly of claim 36 wherein the stand-offs comprises a three-dimensional stereolithography material, an epoxy, and/or a UV curable material.

42. The assembly of claim 36 wherein the covers include glass, quartz, and/or other materials transmissive to a desired spectrum of radiation.

43. A microelectronic imager assembly, comprising:

a workpiece comprising;

a substrate including a front side and a backside; and

a plurality of imaging dies formed at least partially within the substrate, the imaging dies comprising image sensors at the front side of the substrate, integrated circuitry operatively coupled to the image sensors, and bond-pads at the front side of the substrate electrically coupled to the integrated circuitry;

a plurality of spacers projecting from the front side of the substrate, each spacer comprising a front side and a back side, the back side of the spacer being in contact with the front side of the substrate, and openings aligned with the image sensors;

a plurality of covers over corresponding image sensors, the individual covers being supported by the spacers at a corresponding die and transmissive to a desired radiation for the image sensors; and

a plurality of connectors terminating at the front side of the spacers and electrically coupled at the front side of the substrate to corresponding bond-pads of the imaging dies.

44. The assembly of claim 43 wherein the spacers comprise a three-dimensional stereolithography material, an epoxy, and/or a UV curable material.

45. The assembly of claim 43 wherein the covers includes glass, quartz, and/or other materials transmissive to a desired spectrum of radiation.

46. The assembly of claim 43 wherein:

the spacers comprise steps and sidewalls defining interface features; and

the covers are seated with the interface features at a corresponding die.

47. The assembly of claim 43, further comprising a plurality of optical devices attached to the spacers and/or the substrate, the optical devices having optics elements positioned at a desired location relative to corresponding image sensors.

48. The assembly of claim 43, further comprising a plurality of optical devices attached to the spacers and/or the substrate, and wherein the optical devices include focus lenses, dispersion lenses, pin-hole lenses, filters, and/or anti-reflective films.

49. A microelectronic imager, comprising:

a microelectronic die having a front side and a backside, an image sensor formed within the front side, an integrated circuit electrically coupled to the image sensor, and a plurality of bond-pads at the front side electrically coupled to the integrated circuit;

a stand-off projecting from the die and having an opening aligned with the image sensor, the stand-off comprising a front side and a back side, the back side of the stand-off being in contact with the front side of the die, and a three-dimensional stereolithography material, an epoxy, and/or a UV curable material;

a plurality of interconnects extending through the stand-off and electrically coupled at the front side of the die to corresponding bond-pads of the microelectronic die, the interconnects including first end portions electrically coupled to the bond-pads and second end portions at the front side of the stand-off, spaced apart from the first end portions;

a plurality of connectors electrically coupled to the second end portions of the interconnects so as to each abut the front side of the stand-off;

a cover over the image sensor and attached to the stand-off, wherein the cover is transmissive to a desired radiation for the image sensor; and

an optical device attached to the stand-off and/or the cover, the individual optical device including a substrate with an optics element on and/or in the substrate at a desired location relative to the image sensor, the optical devices including a focus lens, a dispersion lens, a pin-hole lens, a filter, and/or an anti-reflective film.

50. The imager of claim 49 wherein:

the stand-off includes passages extending completely through the stand-off and aligned with corresponding bond-pads; and

the interconnect comprise a conductive fill material disposed in the passage and electrically coupled to corresponding bond-pads.

51. The imager of claim 49 wherein:

the stand-off comprises a first mounting site having a first step and a second mounting site having a second step;

the cover is seated with the first step; and

the optical device is seated with the second step to position the optics element at a desired location relative to the image sensor.