Compact sensor module

• US 10,340,302 B2
• Filed: 07/22/2015
• Issued: 07/02/2019
• Est. Priority Date: 12/07/2012
• Status: Active Grant

• Current Assignee: Analog Devices, Inc.
• Original Assignee: Analog Devices, Inc.
• Inventors: Bolognia, David Frank, Venkatadri, Vikram
• Primary Examiner(s): Malkowski, Kenneth J
• Application Number:
  US14/805,835
• Publication Number:
  US 20170025463A1
• Time in Patent Office: 1,441 Days
• CPC Class Codes: H01L 27/14618 Containers
• CPC Class Codes: H01L 27/14634 Assemblies, i.e. Hybrid structures
• CPC Class Codes: H01L 27/14636 Interconnect structures
• CPC Class Codes: H01L 27/14643 Photodiode arrays; MOS imagers
• CPC Class Codes: H01L 27/14661 of the hybrid type
• 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: H01L 31/024 Arrangements for cooling, heating, ventilating or temperature compensation for photovoltaic devices H01L31/052
• CPC Class Codes: Y10T 29/49126 Assembling bases

Abstract

Various embodiments of a compact sensor module are disclosed herein. The sensor module can include a stiffener and a sensor substrate wrapped around a side of the stiffener. A sensor die may mounted on the sensor substrate. A processor substrate may be coupled to the sensor substrate. A processor die may be mounted on the processor substrate and may be in electrical communication with the sensor die.

Claims

1. A sensor module for an imaging system, the sensor module comprising:

a sensor substrate;

an imaging sensor die mounted on the sensor substrate, the imaging sensor die comprising a plurality of pixels on a front side of the imaging sensor die; and

a support structure disposed behind the imaging sensor die, the support structure comprising a back side that faces away from the front side of the imaging sensor die,

the support structure comprising an alignment feature on the back side of the support structure, the support structure having a planar portion that is generally parallel to the imaging sensor die, the support structure providing mechanical support to the sensor module, the alignment feature positioned at a fixed displacement from a reference pixel of the plurality of pixels, the alignment feature exposed on an outermost surface of the sensor module and aligned behind a back side of the imaging sensor die, wherein the alignment feature comprises an alignment hole extending into the support structure of the sensor module,

wherein the alignment feature is configured to mechanically connect to a corresponding alignment pin of the imaging system.

2. The sensor module of claim 1, wherein the alignment feature comprises two alignment holes on opposing corners of the support structure.

3. The sensor module of claim 1, further comprising a processor substrate and one or more processor dies mounted to the processor substrate, the processor substrate wrapped around a side of the support structure.

4. The sensor module of claim 1, further comprising a stiffener and a heat spreader, the sensor substrate wrapped around a side of the stiffener, the support structure disposed between the heat spreader and the stiffener, wherein the heat spreader is directly attached to the stiffener and the support structure is not directly attached to the heat spreader or the stiffener.

5. The sensor module of claim 1, wherein the imaging sensor die comprises a photodiode array (PDA).

6. An imaging system comprising a first module comprising the sensor module of claim 1 and a bracket mechanically supporting the sensor module, wherein the bracket comprises the corresponding alignment pin such that, when the alignment feature of the first module is engaged with the corresponding alignment pin, the reference pixel is at a known coordinate in a reference system of the imaging system.

7. The sensor module of claim 1, wherein the alignment hole comprises a drilled hole.

8. The sensor module of claim 1, wherein the alignment hole is an unthreaded hole.

9. An imaging system comprising a first module comprising the sensor module of claim 1, a second module comprising the sensor module of claim 1 and a bracket mechanically supporting the first and second module, wherein the bracket comprises the corresponding alignment pins for the first and second modules such that, when the alignment features of the first and second modules are engaged with the corresponding alignment pins, the reference pixels of the first and second modules are at known coordinates in a reference system of the imaging with a tolerance less than 100 microns.

10. A sensor module for an imaging system, the sensor module comprising:

a sensor substrate;

an imaging sensor die mounted on the sensor substrate, the imaging sensor die comprising a plurality of pixels on a front side of the imaging sensor die;

a support structure disposed behind the imaging sensor die, the support structure comprising a back side that faces away from the front side of the imaging sensor die, the support structure comprising an alignment feature on the back side of the support structure, the alignment feature positioned at a fixed displacement from a reference pixel of the plurality of pixels, wherein the alignment feature is configured to mechanically connect to a corresponding alignment mechanism of the imaging system;

a plurality of interconnects electrically connecting the imaging sensor die with the sensor substrate; and

an adhesive disposed between the imaging sensor die and the sensor substrate, the adhesive disposed around each of the interconnects,

wherein a first portion of the adhesive is exposed along a first edge of the sensor module, the first portion comprising a negative fillet that does not extend beyond an outer perimeter of the imaging sensor die.

11. The sensor module of claim 10, wherein the negative fillet comprises a concave surface which curves inwardly between the imaging sensor die and the sensor substrate.

12. The sensor module of claim 10, wherein a second portion of the adhesive is exposed along a second edge of the sensor module, the second portion comprising a flat surface.

13. The sensor module of claim 12, wherein a third portion of the adhesive is exposed along a third edge of the sensor module, the third portion comprising a negative fillet.

14. The sensor module of claim 10, wherein the plurality of interconnects comprises a plurality of solder balls.

15. The sensor module of claim 10, further comprising a stiffener, the sensor substrate wrapped around a side of the stiffener.

16. The sensor module of claim 15, wherein the sensor substrate comprises a bend where the sensor substrate is wrapped around the stiffener, the first edge disposed adjacent to and parallel to the bend.

17. A sensor module for an imaging system, the sensor module comprising:

a sensor substrate;

an imaging sensor die mounted on the sensor substrate, the imaging sensor die comprising a plurality of pixels on a front side of the imaging sensor die;

a support structure disposed behind the imaging sensor die, the support structure comprising a back side that faces away from the front side of the imaging sensor die, the support structure comprising an alignment feature on the back side of the support structure, the alignment feature positioned at a fixed displacement from a reference pixel of the plurality of pixels, wherein the alignment feature is configured to mechanically connect to a corresponding alignment mechanism of the imaging system;

a stiffener, wherein the sensor substrate is wrapped around a side of the stiffener, the sensor substrate comprising a front side and a rear side, the sensor substrate comprising a dielectric buffer layer on the rear side of the sensor substrate and one or more conductive traces on the front side of the sensor substrate, and wherein the imaging sensor die is mounted to the front side of the sensor substrate; and

an adhesive between the dielectric buffer layer and the stiffener.

18. The sensor module of claim 17, wherein the dielectric buffer layer comprises polyimide.

19. The sensor module of claim 17, wherein the dielectric buffer layer covers substantially the entire back side of the sensor substrate.

20. The sensor module of claim 19, further comprising a solder mask disposed on a portion of the front side of the sensor substrate but not on the rear side of the sensor substrate.

21. The sensor module of claim 17, wherein the sensor substrate comprises an insulating layer, a first conductive layer on a front side of the insulating layer, and a second conductive layer on a rear side of the insulating layer, the dielectric buffer layer disposed on the second conductive layer.