INTEGRATED CIRCUIT INCLUDING SENSOR HAVING INJECTION MOLDED MAGNETIC MATERIAL

• US 20090140725A1
• Filed: 12/04/2007
• Published: 06/04/2009
• Est. Priority Date: 12/04/2007
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Ausserlechner, Udo
• Granted Patent: US 8,587,297 B2
• Time in Patent Office: Days
• US Class Current: 324/207.200
• CPC Class Codes: G01R 33/072 Constructional adaptation of the sensor to specific applications
• CPC Class Codes: H01L 2224/32245 the item being metallic
• 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 2224/48472 the other connecting portion not on the bonding area also being a wedge bond, i.e. wedge-to-wedge
• CPC Class Codes: H01L 2224/49171 Fan-out arrangements
• CPC Class Codes: H01L 2224/73265 Layer and wire 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 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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: H10N 50/00 Galvanomagnetic devices Hall-effect devices H10N52/00; integrated devices or assemblies of multiple devices H10N59/00
• CPC Class Codes: H10N 50/01 Manufacture or treatment
• CPC Class Codes: H10N 50/80 Constructional details
• CPC Class Codes: Y10T 29/49121 Beam lead frame or beam lead device
• CPC Class Codes: Y10T 29/49158 with molding of insulated base

Abstract

An integrated circuit includes a magnetic field sensor and an injection molded magnetic material enclosing at least a portion of the magnetic field sensor.

Claims

1. An integrated circuit comprising:

a magnetic field sensor; and

an injection molded magnetic material enclosing at least a portion of the magnetic field sensor.

2. The integrated circuit of claim 1, wherein the magnetic field sensor comprises:

a leadframe; and

a die coupled to the leadframe, the die including a magnetic field sensitive element.

3. The integrated circuit of claim 1, wherein the injection molded magnetic material comprises:

a first injection molded magnetic material having a first remanence, the first injection molded magnetic material adjacent a first side of the magnetic field sensor; and

a second injection molded magnetic material having a second remanence less than the first remanence, the second injection molded magnetic material adjacent a second side of the magnetic field sensor opposite the first side.

4. The integrated circuit of claim 1, wherein the injection molded magnetic material comprises:

first injection molded magnetic material adjacent a first side of the magnetic field sensor; and

second injection molded magnetic material adjacent a second side of the magnetic field sensor opposite the first side, the second injection molded magnetic material including a recessed portion.

5. The integrated circuit of claim 1, wherein the injection molded magnetic material comprises:

first injection molded magnetic material having a first thickness adjacent a first side of the magnetic field sensor; and

second injection molded magnetic material having a second thickness greater than the first thickness, the second injection molded magnetic material adjacent a second side of the magnetic field sensor opposite the first side.

6. The integrated circuit of claim 1, further comprising:

an injection molded plastic material enclosing at least a portion of the magnetic field sensor.

7. The integrated circuit of claim 6, wherein the injection molded plastic material is adjacent a first side of the magnetic field sensor, and

wherein the injection molded magnetic material is adjacent a second side of the magnetic field sensor opposite the first side.

8. The integrated circuit of claim 6, wherein the injection molded plastic material encloses the magnetic field sensor, and

wherein the injection molded magnetic material is coupled to at least a portion of the injection molded plastic material.

9. The integrated circuit of claim 8, wherein the injection molded magnetic material is one of mechanically coupled and chemically coupled to the injection molded plastic material.

10. A system comprising:

a magnetic field sensor; and

a controller coupled to the magnetic field sensor,

wherein the magnetic field sensor comprises;

a leadframe;

a die including a magnetic field sensitive element, the die coupled to a front side of the leadframe; and

a magnetic material injection molded over a back side of the leadframe.

11. The system of claim 10, wherein the magnetic field sensor further comprises:

magnetic material injection molded over the die.

12. The system of claim 10, wherein the magnetic field sensor further comprises:

plastic material injection molded over the die.

13. The system of claim 10, wherein the magnetic field sensitive element comprises one of a hall sensor element and a magneto-resistive sensor element.

14. A sensor comprising:

a leadframe;

a die including magnetic field sensitive elements, the die coupled to a front side of the leadframe;

pins;

bond wires electrically coupling the die to the pins; and

a first magnetic material injection molded adjacent a back side of the leadframe.

15. The sensor of claim 14, wherein the magnetic field sensitive elements comprise one of hall elements and magneto-resistive elements.

16. The sensor of claim 14, further comprising:

a second magnetic material injection molded adjacent the die,

wherein the second magnetic material has a remanence greater than a remanence of the first magnetic material.

17. The sensor of claim 14, wherein the first magnetic material includes a central recess.

18. The sensor of claim 14, further comprising:

a plastic material injection molded adjacent the die.

19. A method for fabricating an integrated circuit, the method comprising:

providing a magnetic field sensor; and

injection molding magnetic material over at least a portion of the magnetic field sensor.

20. The method of claim 19, further comprising:

injection molding plastic material over at least a portion of the magnetic field sensor.

21. The method of claim 20, wherein injection molding the magnetic material comprises injection molding the magnetic material over a first side of the magnetic field sensor, and wherein injection molding the plastic material comprises injection molding the plastic material over a second side of the magnetic field sensor opposite the first side.

22. The method of claim 20, wherein injection molding the plastic material comprises injection molding the plastic material to enclose the magnetic field sensor, and wherein injection molding the magnetic material comprises injection molding the magnetic material over the plastic material on one side of the magnetic field sensor.

23. The method of claim 19, wherein injection molding magnetic material comprises:

injection molding a first magnetic material having a first remanence over a first side of the magnetic field sensor; and

injection molding a second magnetic material having a second remanence less than the first remanence over a second side of the magnetic field sensor opposite the first side.

24. A method for fabricating a sensor, the method comprising:

providing a leadframe belt including a leadframe and pins;

attaching a magnetic field sensor die to the leadframe;

electrically coupling the die to the pins to provide a magnetic field sensor assembly;

injection molding magnetic material over at least a portion of the magnetic field sensor assembly to provide a magnetic field sensor; and

removing the magnetic field sensor from the leadframe belt.

25. The method of claim 24, further comprising:

injection molding plastic material over at least a portion of the magnetic field sensor assembly.