Compact sensor module

• US 8,829,454 B2
• Filed: 02/27/2012
• Issued: 09/09/2014
• Est. Priority Date: 02/27/2012
• Status: Active Grant

• Current Assignee: Analog Devices, Inc.
• Original Assignee: Analog Devices, Inc.
• Inventors: Bolognia, David Frank
• Primary Examiner(s): Bryant, Casey
• Application Number:
  US13/405,594
• Publication Number:
  US 20130221468A1
• Time in Patent Office: 925 Days
• Field of Search: 250/370.09, 250/363.04
• US Class Current: 250/370.09
• CPC Class Codes: G01T 1/16 Measuring radiation intensity G01T1/29 takes precedence ; self-powered detectors G01T3/006; using an ionisation chamber filled with a liquid or solid, e.g. frozen liquid, dielectric G01T3/008
• CPC Class Codes: G01T 1/24 with semiconductor detectors
• CPC Class Codes: H01L 25/165 Containers
• CPC Class Codes: H01L 27/14618 Containers
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 31/024 Arrangements for cooling, heating, ventilating or temperature compensation for photovoltaic devices H01L31/052
• CPC Class Codes: H01L 31/115 Devices sensitive to very short wavelength, e.g. X-rays, gamma-rays or corpuscular radiation

Abstract

A compact sensor module and methods for forming the same are disclosed herein. In some embodiments, a sensor die is mounted on a sensor substrate. A processor die can be mounted on a flexible processor substrate. In some arrangements, a thermally insulating stiffener can be disposed between the sensor substrate and the flexible processor substrate. At least one end portion of the flexible processor substrate can be bent around an edge of the stiffener to electrically couple to the sensor substrate.

Claims

1. A sensor module comprising:

a sensor substrate;

a sensor die mounted on the sensor substrate;

a flexible processor substrate having a mounting portion and at least one end portion extending from the mounting portion;

a processor die mounted on the mounting portion of the flexible processor substrate; and

a stiffener having a first side and a second side opposite the first side, the first and second sides including major surfaces of the stiffener, the stiffener disposed between the sensor substrate and the mounting portion of the flexible processor substrate such that the first side faces the sensor substrate and a first normal line passes perpendicularly through the major surface of the first side and intercepts the sensor substrate, and such that the second side faces the mounting portion of the flexible processor substrate and a second normal line passes perpendicularly through the major surface of the second side and intercepts the mounting portion of the flexible processor substrate, wherein the end portion of the flexible processor substrate is bent around an edge of the stiffener to electrically couple to the sensor substrate.

2. The sensor module of claim 1, wherein the sensor die comprises an image sensor die.

3. The sensor module of claim 2, wherein the sensor die comprises a photodiode array.

4. The sensor module of claim 1, wherein first and second opposite end portions of the flexible processor substrate bend around edges of the stiffener to electrically connect to the sensor substrate.

5. The sensor module of claim 4, wherein the mounting portion of the flexible processor substrate is coupled to the second side of the stiffener.

6. The sensor module of claim 5, further comprising a radiation shield attached to the first side of the stiffener and positioned between the stiffener and the sensor substrate.

7. The sensor module of claim 6, wherein the radiation shield is made of tungsten (W) and is configured to substantially shield the processor die from x-ray radiation.

8. The sensor module of claim 6, wherein the radiation shield is housed within a recess formed in the first side of the stiffener, and wherein the flexible processor substrate is housed within a second recess formed in the second side of the stiffener.

9. The sensor module of claim 5, the mounting portion of the flexible processor substrate having a first surface facing the stiffener and a second surface opposite the first surface, and wherein the processor die is mounted on the second surface of the mounting portion.

10. The sensor module of claim 9, further comprising a plurality of passive electrical components electrically coupled to the first surface of the mounting portion and positioned within at least one recess formed in the second side of the stiffener.

11. The sensor module of claim 9, further comprising a thermally conductive heat spreader attached to the second side of the stiffener, wherein the processor die is disposed between the stiffener and the heat spreader.

12. The sensor module of claim 11, further comprising a thermally conductive grease or filler material applied between the processor die and the heat spreader.

13. The sensor module of claim 11, further comprising a connector extending through an opening in the heat spreader and electrically connecting to the flexible processor substrate.

14. The sensor module of claim 11, further comprising a pigtail connector extending from an outer edge of the stiffener and electrically connecting to the flexible processor substrate.

15. An imaging device comprising an array of multiple sensor modules, each sensor module in the array comprising the sensor module of claim 1.

16. The imaging device of claim 15, wherein the imaging device is a CT device.

17. The sensor module of claim 1, wherein the stiffener is a thermally insulating stiffener.

18. A sensor module comprising:

a sensor substrate;

a sensor die mounted on the sensor substrate;

a flexible processor substrate having a mounting portion and at least one end portion extending from the mounting portion;

a processor die mounted on the mounting portion of the flexible processor substrate; and

a stiffener disposed between the sensor substrate and the mounting portion of the flexible processor substrate, wherein first and second opposite end portions of the flexible processor substrate bend around edges of the stiffener to electrically connect to the sensor substrate,

wherein the first end portion of the flexible processor substrate is bent through a first aperture formed in the stiffener to electrically communicate with the sensor substrate, and wherein the second end portion of the flexible processor substrate is bent through a second aperture formed in the stiffener to electrically communicate with the sensor substrate.

19. The sensor module of claim 18, wherein the first end portion is further folded over at least part of a first side of the stiffener, and wherein the second end portion is folded over at least part of the first side of the stiffener.

20. The sensor module of claim 19, wherein the first end portion is folded over at least part of a radiation shield mounted on the first side of the stiffener.

21. A method for forming a sensor module, the method comprising:

providing a sensor substrate, a flexible processor substrate having a mounting portion and a first end portion extending from the mounting portion, and a stiffener having a first side and a second side opposite the first side, the first and second sides including major surfaces of the stiffener;

mounting a sensor die to the sensor substrate;

mounting a processor die to the mounting portion of the flexible processor substrate;

disposing the stiffener between the sensor substrate and the mounting portion of the flexible processor substrate; and

bending the first end portion of the flexible processor substrate around an edge of the stiffener to electrically couple the first end portion of the flexible processor substrate to the sensor substrate, wherein the first side of the stiffener faces the sensor substrate and a first normal line passes perpendicularly through the major surface of the first side and intercepts the sensor substrate, and wherein the second side faces the mounting portion of the flexible processor substrate and a second normal line passes perpendicularly through the major surface of the second side and intercepts the mounting portion of the flexible processor substrate.

22. The method of claim 21, further comprising mounting a radiation shield to the first side of the stiffener between the stiffener and the sensor substrate.

23. The method of claim 22, further comprising attaching the sensor substrate to the shield or to the first side of the stiffener.

24. The method of claim 21, further comprising bending a second end portion of the flexible processor substrate around another edge of the stiffener and electrically coupling the second end portion of the flexible processor substrate to the sensor substrate.

25. The method of claim 24, further comprising folding the first and second end portions over at least part of the first side of the stiffener.

26. The method of claim 21, further comprising attaching a heat spreader to the second side of the stiffener, wherein the processor die is positioned between the stiffener and the heat spreader.

27. The method of claim 26, further comprising applying a thermally conductive grease or filler material between the processor die and the heat spreader.

28. The method of claim 21, further comprising electrically coupling a connector to the flexible processor substrate through an opening in the heat spreader.

29. The method of claim 21, further comprising electrically coupling a capacitor to the flexible processor substrate.

30. The method of claim 21, wherein the stiffener is a thermally insulating stiffener.