Hall-effect sensor isolator

• US 10,283,699 B2
• Filed: 01/29/2016
• Issued: 05/07/2019
• Est. Priority Date: 01/29/2016
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Inventors: Chew, Yin Yin, Tay, Thiam Siew Gary, Ho, Dominique
• Primary Examiner(s): Malek, Maliheh
• Application Number:
  US15/011,167
• Publication Number:
  US 20170222131A1
• Time in Patent Office: 1,194 Days
• CPC Class Codes: H01L 21/56 Encapsulations, e.g. encapsulation layers, coatings
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48245 the item being metallic
• CPC Class Codes: H01L 2224/49171 Fan-out arrangements
• CPC Class Codes: H01L 23/3107 the device being completely enclosed
• CPC Class Codes: H01L 23/49537 Plurality of lead frames mounted in one device
• CPC Class Codes: H01L 23/49551 characterised by bent parts
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/49 of a plurality of wire connectors
• CPC Class Codes: H01L 24/85 using a wire connector wire bonding in general B23K20/004
• 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: H03K 17/9517 using galvanomagnetic devices
• 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 52/80 Constructional details

Abstract

A coupler is disclosed that employs hall-effect sensing technology. Specifically, the coupler is configured to produce an output voltage by converting the magnetic field generated by a current conductor at an input side. The output and input sides may be electrically isolated from one another but may be coupled via the hall-effect sensing technology, such as a hall-effect sensor. The output and input sides may be provided in an overlapping configuration.

Claims

1. A coupler, comprising:

a first conductor configured to induce a magnetic field as electrical current flows through the first conductor;

a second conductor that is electrically isolated from the first conductor;

a semiconductor connected to a first surface of the second conductor, wherein the semiconductor comprises a top surface with a magnetic sensor provided thereon;

an isolation material sandwiched between the top surface of the semiconductor and the first conductor, the isolation material providing an electrical isolation between the first conductor and both the semiconductor as well as the second conductor;

an encapsulant that substantially encapsulates the semiconductor, a piece of the first conductor, a piece of the second conductor, and the isolation material; and

one or more bondwires connected between one or more bond pads of the semiconductor and the second conductor.

2. The coupler of claim 1, wherein the isolation material comprises a high voltage isolation tape.

3. The coupler of claim 2, wherein the high voltage isolation tape overlaps at least sixty percent and no more than ninety percent of the top surface of the semiconductor.

4. The coupler of claim 2, wherein the high voltage isolation tape is structurally self supporting and extends laterally beyond at least one of the first conductor and the semiconductor.

5. The coupler of claim 1, wherein the isolation material comprises a high voltage tolerance as compared to the encapsulant.

6. The coupler of claim 1, wherein a portion of the semiconductor is not overlapped by the isolation material and wherein the portion of the semiconductor that is not overlapped by the isolation material comprises the one or more bond pads that provide a connection point to the semiconductor for the one or more bondwires.

7. The coupler of claim 1, wherein another piece of the first conductor and another piece of the second conductor are external to the encapsulant for external to make electrical connections to components external to the coupler.

8. The coupler of claim 1, wherein the second conductor comprises at least two bends that form a jogged configuration.

9. A coupler, comprising:

a first conductor configured to induce a magnetic field as electrical current flows through the first conductor;

a second conductor that is electrically isolated from the first conductor;

a semiconductor connected to a first surface of the second conductor, wherein the semiconductor comprises a top surface with a magnetic sensor provided thereon;

an isolation material sandwiched between the top surface of the semiconductor and the first conductor, the isolation material providing an electrical isolation between the first conductor and both the semiconductor as well as the second conductor, wherein the first conductor comprises a pair of parallel input leads and a pair of parallel output leads that are connected with a bridge that extends laterally over the semiconductor.

10. The coupler of claim 9, wherein the bridge is shaped to induce the magnetic field as current flows from the input leads to the output leads via the bridge.

11. The coupler of claim 10, wherein the magnetic sensor is positioned substantially underneath a field inducement area created between the pair of parallel input leads, the pair of parallel output leads, and the bridge.

12. A magnetic field-based isolation coupler, comprising:

a first leadframe portion having a field inducement area through which a magnetic field is created when current flows through the first leadframe portion;

a semiconductor having a magnetic sensor provided thereon; and

an isolation material sandwiched between the semiconductor and the first leadframe portion, wherein the isolation material comprises a top face that is facing toward the first leadframe portion and an opposing bottom face that is facing toward the semiconductor,

wherein the first leadframe portion includes a first bend that bends the first leadframe portion in a first direction, and a second bend that bends the first leadframe portion in a second direction that is parallel to the top surface, and

wherein the isolation material is sandwiched between the semiconductor and an end of the first leadframe portion that is closer to the second bend than the first bend.

13. The coupler of claim 12, further comprising:

a second leadframe portion having a first surface and an opposing second surface, the second leadframe portion comprising a support on which the semiconductor is mounted on the first surface of the second leadframe portion, wherein the first direction at least partially perpendicular to the second direction.

14. The coupler of claim 13, wherein the second leadframe portion comprises a jogged configuration that situates the second leadframe portion in a partial overlapping configuration with the first leadframe portion.

15. The coupler of claim 13, wherein the isolation material extends laterally beyond an end of the semiconductor by a first lateral distance and wherein the isolation material extends laterally beyond the end of the first leadframe portion by a second lateral distance.

16. The coupler of claim 15, wherein at least some of the semiconductor is not overlapped by the isolation material thereby providing a connection site for one or more wirebonds.

17. The coupler of claim 12, wherein the isolation material is attached directly to the first leadframe portion and a gap exists between the isolation material and the semiconductor.

18. The coupler of claim 12, wherein the isolation material is attached directly to the semiconductor and a gap exists between the isolation material and the first leadframe portion.

19. The coupler of claim 12, wherein the isolation material comprises a high voltage isolation tape.

20. A magnetic field-based isolation coupler, comprising:

a first leadframe portion having a field inducement area through which a magnetic field is created when current flows through the first leadframe portion;

a semiconductor having a magnetic sensor provided thereon;

an isolation material sandwiched between the semiconductor and the first leadframe portion, wherein the isolation material comprises a top face that is facing toward the first leadframe portion and an opposing bottom face that is facing toward the semiconductor;

a second leadframe portion having a first surface and an opposing second surface, the second leadframe portion comprising a support on which the semiconductor is mounted on the first surface of the second leadframe portion; and

an encapsulant that encapsulates the semiconductor and the isolation material, wherein the encapsulant also partially encapsulates the first leadframe portion and the second leadframe portion.