Apparatus and method for microelectromechanical systems device packaging

• US 8,692,366 B2
• Filed: 04/12/2011
• Issued: 04/08/2014
• Est. Priority Date: 09/30/2010
• Status: Active Grant

• Current Assignee: Analog Devices, Inc.
• Original Assignee: Analog Devices, Inc.
• Inventors: Xue, Xiaojie, Raleigh, Carl
• Primary Examiner(s): Fahmy, Wael
• Assistant Examiner(s): SALERNO, SARAH KATE
• Application Number:
  US13/085,294
• Publication Number:
  US 20120080764A1
• Time in Patent Office: 1,092 Days
• Field of Search: 257/415, 257/417, 257/422, 257/E23.181, 257/E23.184, 257/E23.174, 257/E23.079, 257/E23.004, 257/E23.175, 257/692
• US Class Current: 257/692
• CPC Class Codes: B81B 7/0074 3D packaging, i.e. encapsulation containing one or several MEMS devices arranged in planes non-parallel to the mounting board
• CPC Class Codes: H01L 2224/48091 Arched
• 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

Abstract

A MEMS package includes a substrate having an L-shaped cross-section. The substrate includes a vertical portion having a front surface and a back surface, and a horizontal portion protruding from a lower part of the front surface of the vertical portion, wherein the front surface of the vertical portion includes a mounting region. A MEMS die is mounted on the mounting region such that the MEMS die is oriented substantially parallel to the front surface; a lid attached to the front surface of the substrate while covering the MEMS die; and a plurality of leads formed on a bottom surface of the substrate. The leads can extend substantially parallel to one another, and substantially perpendicular to the front surface. The MEMS die can be oriented substantially perpendicular to a PCB substrate on which the package is mounted.

Claims

1. A microelectromechanical systems (MEMS) package comprising:

an L-shaped substrate comprising;

a vertical portion having a horizontal top surface, a vertical front surface, and a vertical back surface, wherein the front surface of the vertical portion includes a mounting region;

a horizontal portion protruding horizontally from a lower part of the front surface of the vertical portion;

a plurality of leads formed on a bottom surface of the horizontal portion of the substrate; and

a plurality of grooves extending in a direction perpendicular to the front surface, each of the plurality of grooves extending through the entire length of the horizontal portion of the substrate and a lower part of the vertical portion of the substrate, wherein each of the leads is formed inside a respective one of the grooves;

a MEMS die mounted on the mounting region of the substrate such that the MEMS die is oriented substantially parallel to the front surface; and

a lid attached to the front surface of the substrate while covering the MEMS die.

2. The package of claim 1, wherein the leads extend substantially parallel to one another.

3. The package of claim 1, wherein the substrate has a height extending vertically from the bottom surface of the substrate to the top surface of the vertical portion, and a width extending perpendicular to the front surface and the height, and wherein a ratio of the height to the width is between about 0.2 and about 30.

4. The package of claim 1, wherein the substrate comprises a printed circuit board (PCB).

5. The package of claim 4, wherein the vertical portion and the horizontal portion of the substrate are laminated to each other.

6. The package of claim 1, wherein the substrate comprises a ceramic material or a plastic material.

7. The package of claim 1, further comprising bond pads on the mounting region of the substrate, and bond wires or bumps electrically coupled between the bond pads and the MEMS die.

8. The package of claim 7, further comprising a plurality of interconnects embedded in the vertical portion of the substrate, wherein a plurality of the interconnects are electrically coupled between one of the bond pads and a respective one of the leads.

9. The package of claim 1, further comprising a die mount on the mounting region of the substrate such that the die mount is interposed between the front surface of the substrate and the MEMS die.

10. The package of claim 1, wherein the lid comprises a conductive material which is configured to be electrically coupled to electrical ground.

11. The package of claim 10, wherein the lid is formed of a metal.

12. The package of claim 10, wherein the lid comprises a plastic material coated with the conductive material.

13. The package of claim 1, further comprising solder or conductive epoxy interposed between the lid and the first surface of the substrate.

14. The package of claim 1, wherein the grooves are open in directions in which the front and back surfaces face such that end portions of the leads are visible when viewed from either the front or back side of the package.

15. The package of claim 14, wherein the substrate further comprises a first pad extending from one of the end portions of one of the leads, and wherein the first pad is formed on a vertical surface of the horizontal portion.

16. The package of claim 15, wherein the substrate further comprises a second pad extending from another of the end portions of the lead, and wherein the second pad is formed on the vertical back surface of the horizontal portion.

17. The package of claim 1, wherein the leads have concave bottom surfaces.

18. The package of claim 1, further comprising an electromagnetic interference (EMI) shield conductive plate on the back surface of the vertical portion or embedded in the vertical portion.

19. The package of claim 1, further comprising an EMI shield conductive paddle formed on the mounting region of the substrate such that the paddle is interposed between the MEMS die and the front surface of the vertical portion.

20. The package of claim 1, further comprising a plurality of additional leads formed on a portion of the back surface of the vertical portion, the additional leads being spaced apart from the plurality of leads.

21. The package of claim 1, wherein the MEMS die comprises a gyroscope or accelerometer.

22. A substrate for a microelectromechanical systems (MEMS) package comprising:

a substrate having an L-shaped cross-section, the substrate comprising;

a vertical portion having a vertical front surface and a vertical back surface, wherein the vertical portion includes a mounting region on the front surface, bond pads on the mounting region, and interconnects electrically coupled to the bond pads;

a horizontal portion protruding horizontally from a lower part of the front surface of the vertical portion, wherein the front surface of the vertical portion includes a mounting region;

a plurality of leads formed on a bottom surface of the horizontal portion of the substrate; and

a plurality of grooves extending through the horizontal portion of the substrate and a lower part of the vertical portion of the substrate, the grooves extending through the entire length of the horizontal portion of the substrate and a lower part of the vertical portion of the substrate, wherein each of the leads is formed inside a respective one of the grooves.

23. The substrate of claim 22, wherein the leads extend substantially parallel to one another.

24. The substrate of claim 22, further comprising a lid attachable to the front surface of the vertical portion, the lid being configured to cover the mounting region while having a cavity formed on the mounting region.

25. A method of making a microelectromechanical systems (MEMS) package, the method comprising:

providing a substrate comprising a first portion having a first surface including a plurality of die mounting regions, and a second portion elevated from the first surface of the first portion, wherein the second portion is positioned outside the mounting regions, wherein the substrate further comprises a plurality of through-holes formed through the second portion, and a conductive material at least partially filling the through-holes; and

partitioning the substrate into individual MEMS packages such that each of the MEMS packages includes;

a vertical portion having a vertical front surface and a vertical back surface, wherein the front surface of the vertical portion includes one of the mounting regions;

a horizontal portion protruding horizontally from a lower part of the front surface of the vertical portion; and

a plurality of leads formed on a bottom surface of the horizontal portion of the substrate; and

a plurality of grooves defined by portions of the through-holes at least partially filled with the conductive material, the plurality of grooves extending in a direction perpendicular to the front surface, each of the plurality of grooves extending through the entire length of the horizontal portion of the substrate and a lower part of the vertical portion of the substrate, wherein each of the leads comprises the conductive material inside a respective one of the grooves.

26. The method of claim 25, wherein providing the substrate further comprises forming a conductive material on a portion of a top surface of the second portion such that the conductive material extends from the conductive material formed on the inner surfaces of the through-holes.

27. The method of claim 25, wherein providing the substrate further comprises forming a conductive material on a portion of a bottom surface of the second portion such that the conductive material extends from the conductive material formed on the inner surfaces of the through-holes.

28. The method of claim 25, wherein providing the substrate comprises coating the conductive material on the inner surfaces of the through-holes, and filling the through-holes with a conductive or non-conductive material.

29. The method of claim 25, further comprising, before partitioning the substrate:

mounting one or more MEMS dies on each of the mounting regions; and

attaching a plurality of lids to the first surface of the first substrate such that each of the lids covers a respective one of the mounting regions.

30. The method of claim 25, wherein providing the substrate comprises:

providing a first printed circuit board (PCB) having a first surface including the mounting regions;

attaching a second PCB to the first surface of the first PCB, wherein the second PCB is smaller in area than the first substrate, thereby forming the second portion of the substrate;

forming the through-holes through the second portion of the substrate; and

depositing the conductive material on the inner surfaces of the through-holes.

31. The method of claim 30, wherein providing the substrate further comprises depositing the conductive material on portions of top and bottom surfaces of the second portion such that the conductive material extends from the conductive material on the inner surfaces of the through-holes.

32. The method of claim 30, wherein the first PCB includes the mounting regions arranged in at least two rows,

wherein attaching the second PCB comprises attaching the second PCB between two of the rows, and

wherein partitioning the substrate comprises:

sawing the second portion of the substrate in a first direction to separate adjacent rows, and cut the through-holes substantially in half, and

sawing the substrate in a second direction to separate individual ones of the mounting regions.

33. A method of making a microelectromechanical systems (MEMS) package, the method comprising:

providing a substrate having an L-shaped cross-section, the substrate comprising;

a vertical portion having a vertical front surface and a vertical back surface, the front surface including a mounting region;

a horizontal portion protruding horizontally from a lower part of the front surface of the vertical portion;

a plurality of leads formed on a bottom surface of the horizontal portion of the substrate; and

a plurality of grooves extending through the horizontal portion of the substrate and a lower part of the vertical portion of the substrate, the grooves extending through the entire length of the horizontal portion of the substrate and a lower part of the vertical portion of the substrate, wherein each of the leads is formed inside a respective one of the grooves;

mounting one or more MEMS dies on the mounting region of the substrate such that the MEMS dies are oriented substantially parallel to the front surface; and

attaching a lid to the front surface of the substrate so as to cover the one or more MEMS dies.

34. The method of claim 33, wherein the leads extend substantially parallel to one another.