IP Library Granted Patent US 9,620,705
Granted Patent B2
US 9,620,705 · App. 15/049,732 · Granted Apr 11, 2017

Methods and apparatus for magnetic sensor having non-conductive die paddle

Inventors: Shaun D. Milano (Dunbarton, NH); Michael C. Doogue (Bedford, NH); William P. Taylor (Amherst, NH)
Assignee: Allegro MicroSystems, LLC
H01L43/04G01R33/0029G01R33/0076G01R33/07G01R33/09H01L23/3107H01L23/3142H01L23/49503H01L23/49506H01L23/49541H01L23/49575H01L24/17H01L43/02H01L43/065H01L43/08H01L43/12H01L43/14H01L2224/16H01L2224/16245H01L2224/45144H01L2224/4826H01L2224/48091H01L2224/48247H01L2224/48257H01L2224/49171H01L2224/73204H01L2224/73265H01L2924/15311H01L2924/15747H01L2924/3025H01L2924/30107
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Quick Facts
Patent No.
US 9,620,705
App. No.
15/049,732
Granted
Apr 11, 2017
Kind
B2
Abstract

Methods and apparatus to provide a magnetic field sensor device including a magnetic sensor element, a die having wafer bumps, wherein the magnetic sensor element is positioned in relation to the die, and conductive leadfingers having respective portions electrically connected to the wafer bumps. In embodiments, the device includes a region about the magnetic sensor element that does not contain electrically conductive material for preventing eddy current flow.

Claims (57)

1. A magnetic field sensor device, comprising:

a magnetic sensor element;

a die having wafer bumps, wherein the magnetic sensor element is positioned in relation to the die;

a non-conductive die paddle over which the die is disposed;

conductive leadfingers having respective portions electrically connected to the wafer bumps; and

a region about the magnetic sensor element that does not contain electrically conductive leadfinger material for preventing eddy current flow.

2. The device according to claim 1 , wherein the non-conductive die paddle comprises a plastic material.

3. The device according to claim 1 , further including an underfill material proximate the wafer bumps.

4. The device according to claim 1 , further including a magnetic layer aligned with the die to affect magnetic fields proximate the die.

5. The device according to claim 4 , wherein the magnetic layer comprises a soft ferromagnetic material.

6. The device according to claim 4 , wherein the magnetic layer comprises a hard ferromagnetic material.

7. The device according to claim 1 , further including a back-bias magnet.

8. The device according to claim 1 , wherein the conductive leadfinger material is at least a given distance more than a height from the leadfingers to the magnetic sensing element.

9. The device according to claim 1 , wherein the conductive leadfinger material is at least two times a vertical height from the leadfingers to the magnetic sensing element.

10. The device according to claim 1 , wherein the magnetic sensor element is formed in the die.

11. The device according to claim 1 , wherein the magnetic sensor element includes a Hall element.

12. The device according to claim 1 , wherein the magnetic sensor element includes a magnetoresitive element.

13. The device according to claim 1 , wherein the leadfinger material extends from only one side of the magnetic field sensor device.

14. A method, comprising:

providing a magnetic sensor element;

providing a die having wafer bumps, wherein the magnetic sensor element is positioned in relation to the die;

providing conductive leadfingers having respective portions electrically connected to the wafer bumps; and

forming a region about the magnetic sensor element that does not contain electrically conductive material for preventing eddy current flow,

wherein the magnetic sensor element, the die, and the leadfingers form part of a magnetic field sensor IC package.

15. The method according to claim 14 , further providing a non-conductive die paddle on which the die is disposed.

16. The method according to claim 15 , wherein the non-conductive die paddle comprises a plastic material.

17. The method according to claim 14 , further including a magnetic layer aligned with the die to affect magnetic fields proximate the die.

18. The method according to claim 14 , further including a back-bias magnet as part of the IC package.

19. The method according to claim 14 , wherein the conductive leadfinger material is at least a given distance more than a height from the leadfingers to the magnetic sensing element.

20. The method according to claim 14 , wherein the conductive leadfinger material is at least two times a vertical height from the leadfingers to the magnetic sensing element.

21. The method according to claim 14 , wherein the magnetic sensor element is formed in the die.

22. The method according to claim 14 , wherein the magnetic sensor element includes a Hall element.

23. The method according to claim 14 , wherein the magnetic sensor element includes a magnetoresitive element.

24. The method according to claim 14 , wherein the leadfinger material extends from only one side of the magnetic field sensor device.

25. The method according to claim 14 , further including applying an underfill material proximate the wafer bumps.

26. A magnetic field sensor device, comprising:

a magnetic sensor element;

a die having wafer bumps, wherein the magnetic sensor element is positioned in relation to the die;

conductive leadfingers having respective portions electrically connected to the wafer bumps; and

a region about the magnetic sensor element that does not contain electrically conductive material for preventing eddy current flow,

wherein the leadfinger material extends from only one side of the magnetic field sensor device.

27. The device according to claim 26 , further including a non-conductive die paddle on which the die is disposed.

28. The device according to claim 26 , wherein the conductive leadfinger material is at least two times a vertical height from the leadfingers to the magnetic sensing element.

29. The device according to claim 26 , wherein the magnetic sensor element is formed in the die.

30. The device according to claim 26 , wherein the magnetic sensor element includes a Hall element.

31. The device according to claim 26 , wherein the magnetic sensor element includes a magnetoresitive element.

32. A method, comprising:

providing a magnetic sensor element;

providing a die having wafer bumps, wherein the magnetic sensor element is positioned in relation to the die; and

providing conductive leadfingers having respective portions electrically connected to the wafer bumps;

wherein a region about the magnetic sensor element does not contain electrically conductive material for preventing eddy current flow,

wherein the leadfinger material extends from only one side of the magnetic field sensor device, and

wherein the magnetic sensor element, the die, and the leadfingers form part of a magnetic field sensor IC package.

33. The method according to claim 32 , further including providing a non-conductive die paddle over which the die is disposed.

34. The method according to claim 32 , wherein the conductive leadfinger material is at least two times a vertical height from the leadfingers to the magnetic sensing element.

35. The method according to claim 32 , wherein the magnetic sensor element includes a Hall element.

36. The method according to claim 32 , wherein the magnetic sensor element includes a magnetoresitive element.

Assignments (7)
RELEASE OF SECURITY INTEREST IN PATENTS AT REEL 053957/FRAME 0874 Recorded Nov 1, 2023
From: CREDIT SUISSE AG, CAYMAN ISLANDS BRANCH, AS COLLATERAL AGENT
To: ALLEGRO MICROSYSTEMS, LLC
Reel/Frame 065420/0572 →
PATENT SECURITY AGREEMENT Recorded Jun 22, 2023
From: ALLEGRO MICROSYSTEMS, LLC
To: MORGAN STANLEY SENIOR FUNDING, INC., AS THE COLLATERAL AGENT
Reel/Frame 064068/0459 →
RELEASE OF SECURITY INTEREST IN PATENTS (R/F 053957/0620) Recorded Jun 22, 2023
From: MIZUHO BANK, LTD., AS COLLATERAL AGENT
To: ALLEGRO MICROSYSTEMS, LLC
Reel/Frame 064068/0360 →
PATENT SECURITY AGREEMENT Recorded Oct 1, 2020
From: ALLEGRO MICROSYSTEMS, LLC
To: MIZUHO BANK LTD., AS COLLATERAL AGENT
Reel/Frame 053957/0620 →
PATENT SECURITY AGREEMENT Recorded Oct 1, 2020
From: ALLEGRO MICROSYSTEMS, LLC
To: CREDIT SUISSE AG, CAYMAN ISLANDS BRANCH, AS COLLATERAL AGENT
Reel/Frame 053957/0874 →
CHANGE OF NAME Recorded Feb 23, 2016
From: ALLEGRO MICROSYSTEMS, INC.
To: ALLEGRO MICROSYSTEMS, LLC
Reel/Frame 037880/0764 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 23, 2016
From: MILANO, SHAUN D.; DOOGUE, MICHAEL C.; TAYLOR, WILLIAM P.
To: ALLEGRO MICROSYSTEMS, INC.
Reel/Frame 037792/0295 →
Continuity (3)
Division 14090037 · Nov 26, 2013
Continuation 13350970 · Jan 16, 2012
Related Publication 20160172584A1 · Jun 16, 2016