IP Library Granted Patent US 7,358,724
Granted Patent B2
US 7,358,724 · App. 11/129,933 · Granted Apr 15, 2008

Integrated magnetic flux concentrator

Assignee: Allegro Microsystems, Inc.
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Quick Facts
Patent No.
US 7,358,724
App. No.
11/129,933
Granted
Apr 15, 2008
Kind
B2
Abstract

A method and apparatus provide a substrate having a depression into which a magnetic material is disposed, forming a magnetic flux concentrator and/or a permanent magnet. A magnetic field sensing element can be disposed proximate to the depression.

Claims (44)

1. Apparatus, comprising:

a substrate having first and second opposing surfaces;

a magnetic field sensing element disposed on the first surface of the substrate, having first and second opposing magnetic field sensing element surfaces generally parallel to the first surface of the substrate;

a depression disposed in the second surface of the substrate and generally aligned with the magnetic field sensing element, wherein the depression has a first depression surface generally parallel to the first surface of the substrate and adjacent to the magnetic field sensing element and a second depression surface adjacent to the first depression surface; and

a magnetic material layer disposed on at least one of the first depression surface or the second depression surface.

2. The apparatus of claim 1 , wherein the magnetic material layer is comprised of a soft magnetic material.

3. The apparatus of claim 1 , wherein the magnetic material layer is comprised of a hard magnetic material.

4. The apparatus of claim 1 , wherein the second depression surface is generally perpendicular to the first depression surface.

5. The apparatus of claim 1 , wherein the magnetic material layer is formed from a selected one of a ferrite material, Permalloy, NiFeMo, Supermalloy, a Nickel alloy, an Iron alloy, a Cobalt alloy, or a Manganese alloy.

6. The apparatus of claim 1 , wherein the magnetic material layer is disposed with a selected one of a plating process, a sputtering process, or an electron beam process.

7. The apparatus of claim 1 , further comprising a soft magnetic material layer extension disposed on the second surface of the substrate.

8. The apparatus of claim 7 , wherein the soft magnetic material layer extension is disposed with a selected one of a plating process, a sputtering process, or an electron beam process.

9. The apparatus of claim 1 , wherein the depression is a deep reactive ion etch (DRIE) depression.

10. The apparatus of claim 1 , further comprising a second magnetic material layer disposed on the first surface of the magnetic field sensing element surface.

11. The apparatus of claim 10 , wherein the second magnetic material layer is comprised of a soft magnetic material.

12. The apparatus of claim 10 , wherein the second magnetic material layer is comprised of a hard magnetic material.

13. The apparatus of claim 10 , further comprising at least one of: a first soft magnetic material layer extension disposed on the first surface of the substrate or a second soft magnetic material layer extension disposed on the second surface of the substrate.

14. The apparatus of claim 13 , wherein the first soft magnetic material layer extension and the second soft magnetic material layer extension are disposed with a selected one of a plating process, a sputtering process, or an electron beam process.

15. The apparatus of claim 10 , wherein the magnetic material layer is formed from a selected one of a ferrite material, Permalloy, NiFeMo, Supermalloy, a Nickel alloy, an Iron alloy, a Cobalt alloy, or a Manganese alloy.

16. The apparatus of claim 10 , wherein the second magnetic material layer is disposed with a selected one of a plating process, a sputtering process or an electron beam process.

17. The apparatus of claim 1 , wherein the magnetic field sensing element is responsive to a magnetic field associated with an electrical current.

18. The apparatus of claim 1 , wherein the magnetic field sensing element is responsive to a magnetic field external to the apparatus.

19. The apparatus of claim 1 , wherein the magnetic field sensing element is responsive to a magnetic field associated with at least one of a hard magnetic material object or a soft magnetic material object.

20. The apparatus of claim 1 , further including a concentrator apparatus, comprising:

a second substrate having first and second opposing surfaces, wherein the second surface of the second substrate is disposed over a selected one of the first surface of the substrate or the second surface of the substrate and the first surface of the second substrate is disposed over the second surface of the second substrate;

a concentrator apparatus depression disposed in at least one of the first surface or the second surface of the second substrate and generally aligned with the magnetic field sensing element, wherein the concentrator apparatus depression has at least one of a first concentrator apparatus depression surface generally parallel to the second surface of the second substrate and a second concentrator apparatus depression surface; and

a concentrator apparatus magnetic material layer disposed on at least one of the first concentrator apparatus depression surface or the second concentrator apparatus depression surface.

21. The apparatus of claim 20 , wherein the concentrator apparatus magnetic material layer is comprised of a soft magnetic material.

22. The apparatus of claim 20 , wherein the concentrator apparatus magnetic material layer is comprised of a hard magnetic material.

23. The apparatus of claim 20 , wherein the concentrator apparatus magnetic material layer is formed from a selected one of a ferrite material, Permalloy, NiFeMo, Supermalloy, a Nickel alloy, an Iron alloy, a Cobalt alloy, or a Manganese alloy.

24. The apparatus of claim 20 , wherein the concentrator apparatus magnetic material layer is disposed with a selected one of a plating process, a sputtering process, or an electron beam process.

25. The apparatus of claim 20 , wherein the concentrator apparatus depression is a deep reactive ion etch (DRIE) concentrator apparatus depression.

26. The apparatus of claim 20 , further including:

a conductor having a first notch and a second notch substantially aligned with the first notch, wherein the magnetic field sensing element has at least a portion disposed in the first notch; and

a magnetic core having a central region and a pair of substantially parallel legs extending from said central region, wherein at least a portion of said central region is disposed in the second notch and wherein at least a portion of each leg covers at least a portion of a respective surface of the magnetic field sensing element.

27. The apparatus of claim 20 , further including:

a lead frame having a plurality of leads;

a current conductor portion comprising a coupling of at least two of the plurality of leads, wherein the current conductor portion is disposed proximate the first surface of the substrate.

28. The apparatus of claim 1 , further including:

a conductor having a first notch and a second notch substantially aligned with the first notch, wherein the magnetic field sensing element has at least a portion disposed in the first notch; and

a magnetic core having a central region and a pair of substantially parallel legs extending from said central region, wherein at least a portion of said central region is disposed in the second notch and wherein at least a portion of each leg covers at least a portion of a respective surface of the magnetic field sensing element.

29. The apparatus of claim 1 , further including:

a lead frame having a plurality of leads;

a current conductor portion comprising a coupling of at least two of the plurality of leads, wherein the current conductor portion is disposed proximate the first surface of the substrate.

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 →
CONVERSION AND NAME CHANGE Recorded Apr 10, 2013
From: ALLEGRO MICROSYSTEMS, INC.
To: ALLEGRO MICROSYSTEMS, LLC
Reel/Frame 030426/0178 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 16, 2005
From: TAYLOR, WILLIAM T.; DICKINSON, RICHARD; DOOGUE, MICHAEL C.
To: ALLEGRO MICROSYSTEMS, INC.
Reel/Frame 016572/0268 →
Continuity (1)
Related Publication 20060255797A1 · Nov 16, 2006