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

• US 9,620,705 B2
• Filed: 02/22/2016
• Issued: 04/11/2017
• Est. Priority Date: 01/16/2012
• Status: Active Grant

• Current Assignee: Allegro Microsystems Incorporated (Sanken Electric Company Limited)
• Original Assignee: Allegro Microsystems Incorporated (Sanken Electric Company Limited)
• Inventors: Milano, Shaun D., Doogue, Michael C., Taylor, William P.
• Primary Examiner(s): NGO, NGAN V
• Application Number:
  US15/049,732
• Publication Number:
  US 20160172584A1
• Time in Patent Office: 414 Days
• CPC Class Codes: G01R 33/0029 Treating the measured signals, e.g. removing offset or noise
• CPC Class Codes: G01R 33/0052 Manufacturing aspects; Manufacturing of single devices, i.e. of semiconductor magnetic sensor chips devices based on galvano-magnetic effect or the like H10N50/85
• CPC Class Codes: G01R 33/0076 Protection, e.g. with housings against stray fields
• CPC Class Codes: G01R 33/07 Hall effect devices
• CPC Class Codes: G01R 33/09 Magnetoresistive devices
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2224/16245 the item being metallic
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48257 connecting the wire to a die pad of the item
• CPC Class Codes: H01L 2224/4826 Connecting between the body and an opposite side of the item with respect to the body
• CPC Class Codes: H01L 2224/49171 Fan-out arrangements
• CPC Class Codes: H01L 2224/73204 the bump connector being embedded into the layer connector
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 23/3107 the device being completely enclosed
• CPC Class Codes: H01L 23/3142 Sealing arrangements between parts, e.g. adhesion promotors
• CPC Class Codes: H01L 23/49503 characterised by the die pad
• CPC Class Codes: H01L 23/49506 an insulative substrate being used as a diepad, e.g. ceramic, plastic H01L23/49531 takes precedence
• CPC Class Codes: H01L 23/49541 Geometry of the lead-frame
• CPC Class Codes: H01L 23/49575 : Assemblies of semiconductor devices on lead frames
• CPC Class Codes: H01L 24/17 : of a plurality of bump connectors
• 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 2924/00014 : 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 2924/15311 : being a ball array, e.g. BGA
• CPC Class Codes: H01L 2924/15747 : Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/30107 : Inductance
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding
• CPC Class Codes: H10N 50/01 : Manufacture or treatment
• CPC Class Codes: H10N 50/10 : Magnetoresistive devices
• CPC Class Codes: H10N 50/80 : Constructional details
• CPC Class Codes: H10N 52/00 : Hall-effect devices integrated devices or assemblies of multiple devices H10N59/00
• CPC Class Codes: H10N 52/01 : Manufacture or treatment
• CPC Class Codes: H10N 52/101 : Semiconductor Hall-effect devices
• CPC Class Codes: H10N 52/80 : Constructional details

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

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.