Integrated circuit package having a split lead frame

• US 9,494,660 B2
• Filed: 01/25/2013
• Issued: 11/15/2016
• Est. Priority Date: 03/20/2012
• Status: Active Grant

• Current Assignee: Allegro Microsystems Incorporated (Sanken Electric Company Limited)
• Original Assignee: Allegro Microsystems Incorporated (Sanken Electric Company Limited)
• Inventors: David, Paul, Taylor, William P., Scheller, P. Karl, Vig, Ravi, Friedrich, Andreas P.
• Primary Examiner(s): KOVAL, MELISSA J
• Assistant Examiner(s): Maini, Rahul
• Application Number:
  US13/749,776
• Publication Number:
  US 20130249546A1
• Time in Patent Office: 1,390 Days
• Field of Search: 324/260, 324/261, 324/262
• US Class Current: 1/1
• CPC Class Codes: G01R 33/00 Arrangements or instruments for measuring magnetic variables
• CPC Class Codes: G01R 33/0011 comprising means, e.g. flux concentrators, flux guides, for guiding or concentrating the magnetic flux, e.g. to the magnetic sensor
• CPC Class Codes: G01R 33/0047 Housings or packaging of magnetic sensors packaging of semiconductor devices H01L23/00; Holders
• CPC Class Codes: H01L 2224/16245 the item being metallic
• 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 2224/48257 connecting the wire to a die pad of the item
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 23/49562 for devices being provided for in H01L29/00
• CPC Class Codes: H01L 23/49589 Capacitor integral with or on the leadframe
• 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

Abstract

A magnetic field sensor includes a lead frame having a plurality of leads, at least two of which have a connection portion and a die attach portion. A semiconductor die is attached to the die attach portion of the at least two leads. In some embodiments, at least one passive component is attached to the die attach portion of at least two leads.

Claims

1. A magnetic field sensor comprising:

a lead frame having a first surface, a second opposing surface, and comprising a plurality of leads, wherein at least two of the plurality of leads are electrically isolated from each other and wherein each of the at least two leads has an elongated connection portion extending from a die attach portion;

a semiconductor die supporting a magnetic field sensing element and attached to the die attach portions of the at least two leads;

a passive component coupled between the die attach portions of the at least two leads; and

a non-conductive adhesive between the semiconductor die and the die attach portions of the at least two leads.

2. The magnetic field sensor of claim 1 further comprising a non-conductive mold material enclosing the semiconductor die and the die attach portions of the at least two leads.

3. The magnetic field sensor of claim 2 further comprising a ferromagnetic mold material secured to a portion of the non-conductive mold material.

4. The magnetic field sensor of claim 1 wherein the passive component is a capacitor.

5. The magnetic field sensor of claim 1 further comprising at least two passive components, each coupled between a respective pair of die attach portions.

6. The magnetic field sensor of claim 1 further comprising a second passive component coupled to the connection portion of the at least two leads.

7. The magnetic field sensor of claim 1 wherein the connection portion of at least one of the at least two leads has a widened portion extending away from another one of the at least two leads.

8. The magnetic field sensor of claim 1 further comprising a wire bond coupled between the semiconductor die and a location of the die attach portion of at least one of the at least two leads distal from the connection portion of the at least one lead.

9. The magnetic field sensor of claim 1 further comprising a wire bond coupled between the semiconductor die and a location of the die attach portion of at least one of the at least two leads proximate to the connection portion of the at least one lead.

10. The magnetic field sensor of claim 1 wherein at least one of the plurality of leads has a first portion that is separated from a second portion of the lead and wherein the magnetic field sensor further comprises a passive component coupled between the first portion and second portion of the at least one lead.

11. The magnetic field sensor of claim 10 wherein the passive component is a resistor.

12. The magnetic field sensor of claim 10 wherein the semiconductor die is attached to the first portion of the at least one lead and is not attached to the second portion of the at least one lead.

13. The magnetic field sensor of claim 1 wherein the die attach portion of at least one of the at least two leads comprises at least one slot.

14. The magnetic field sensor of claim 1 further comprising a ferromagnetic mold material secured to the elongated connection portion of at least one of the plurality of leads.

15. The magnetic field sensor of claim 1 further comprising a ferromagnetic bead secured to the connection portion of at least one of the plurality of leads.

16. The magnetic field sensor of claim 1 wherein the semiconductor die has a first surface in which the magnetic field sensing element is disposed and a second, opposing surface and wherein the second, opposing surface is attached to the die attach portions of the at least two leads.

17. A magnetic field sensor comprising:

a lead frame having a first surface, a second opposing surface, and comprising a plurality of leads, wherein at least two of the plurality of leads are electrically isolated from each other and wherein each of the at least two leads has an elongated connection portion extending from a die attach portion;

a semiconductor die supporting a magnetic field sensing element and attached to the die attach portions of the at least two leads;

a passive component coupled between the die attach portions of the at least two leads; and

a non-conductive mold material enclosing the semiconductor die and the die attach portions of the at least two leads, wherein the non-conductive mold material has a diameter of less than approximately 7.0 mm.

18. The magnetic field sensor of claim 17 wherein the passive component is a capacitor.

19. A magnetic field sensor comprising:

a lead frame comprising a plurality of leads, wherein at least two of the plurality of leads are electrically isolated from each other and wherein each of the at least two leads has an elongated connection portion extending from a die attach portion;

a semiconductor die supporting a magnetic field sensing element and attached to the die attach portions of the at least two leads;

a non-conductive adhesive between the semiconductor die and the die attach portions of the at least two leads;

at least one passive component coupled between the die attach portions of the at least two leads;

a non-conductive mold material enclosing the semiconductor die, the passive component, and the die attach portions of the at least two leads; and

a ferromagnetic mold material secured to a portion of the non-conductive mold material.

20. The magnetic field sensor of claim 19 wherein the at least one passive component is a capacitor.

21. The magnetic field sensor of claim 19 further comprising at least two passive components, each coupled between a respective pair of die attach portions.

22. The magnetic field sensor of claim 19 further comprising at least one passive component coupled to the connection portion of the at least two leads.

23. The magnetic field sensor of claim 19 wherein the connection portion of at least one of the at least two leads has a widened portion extending away from another one of the at least two leads.

24. The magnetic field sensor of claim 19 further comprising a wire bond coupled between the semiconductor die and a location of the die attach portion of at least one of the at least two leads distal from the connection portion of the at least one lead.

25. The magnetic field sensor of claim 19 further comprising a wire bond coupled between the semiconductor die and a location of the die attach portion of at least one of the at least two leads proximate to the connection portion of the at least one lead.

26. The magnetic field sensor of claim 19 wherein at least one of the plurality of leads has a first portion that is separated from a second portion of the lead and wherein the magnetic field sensor further comprises at least one passive component coupled between the first portion and second portion of the at least one lead.

27. The magnetic field sensor of claim 26 wherein the at least one passive component is a resistor.

28. The magnetic field sensor of claim 19 wherein the die attach portion of at least one of the at least two leads comprises at least one slot.

29. The magnetic field sensor of claim 19 further comprising a ferromagnetic mold material secured to the elongated connection portion of at least one of the plurality of leads.

30. The magnetic field sensor of claim 19 further comprising a ferromagnetic bead secured to the connection portion of at least one of the plurality of leads.