Sensor Package and Method for Producing a Sensor Package

• US 20110234215A1
• Filed: 03/26/2010
• Published: 09/29/2011
• Est. Priority Date: 03/26/2010
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Ausserlechner, Udo
• Granted Patent: US 8,400,139 B2
• Time in Patent Office: Days
• US Class Current: 324/244
• CPC Class Codes: G01R 15/20 using galvano-magnetic devices, e.g. Hall-effect devices , i.e. measuring a magnetic field via the interaction between a current and a magnetic field, e.g. magneto resistive or Hall effect devices
• CPC Class Codes: G01R 15/207 Constructional details independent of the type of device used
• CPC Class Codes: G01R 33/0047 Housings or packaging of magnetic sensors packaging of semiconductor devices H01L23/00; Holders
• CPC Class Codes: G01R 33/02 Measuring direction or magnitude of magnetic fields or magnetic flux G01R33/20 takes precedence
• CPC Class Codes: G01R 33/07 Hall effect devices
• CPC Class Codes: G01R 33/072 Constructional adaptation of the sensor to specific applications
• CPC Class Codes: H01L 2224/48105 Connecting bonding areas at different heights
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/49171 Fan-out arrangements
• 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 2924/01068 Erbium [Er]
• CPC Class Codes: H01L 2924/01087 Francium [Fr]
• CPC Class Codes: H01L 2924/30107 Inductance
• CPC Class Codes: H01L 2924/3025 Electromagnetic shielding
• CPC Class Codes: H05K 3/28 Applying non-metallic protective coatings H05K3/0091 takes precedence; methods for intermediate insulating layers for build-up multilayer circuits H05K3/4673
• CPC Class Codes: H05K 3/30 Assembling printed circuits with electric components, e.g. with resistor
• CPC Class Codes: Y10T 29/49004 including measuring or testing of device or component part
• CPC Class Codes: Y10T 29/4913 Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49133 with component orienting

Abstract

Some embodiments herein relate to a sensor package. The sensor package includes a printed circuit board with a laminar current conductor arranged on a first main surface of the printed circuit board. The sensor package also includes a sensor chip adapted to measure a current flowing through the laminar current conductor, wherein the sensor chip comprises a magnetic field sensor. The sensor chip is electrically insulated from the current conductor by the printed circuit board, and is arranged on a second main surface of the printed circuit board opposite to the first main surface. The sensor chip is hermetically sealed between the mold material and the printed circuit board, or is arranged in the printed circuit board and hermetically sealed by the printed circuit board.

Claims

1. A sensor package, comprising:

a printed circuit board that includes a first main surface and a second main surface, wherein the second main surface is opposite to the first main surface;

a laminar current conductor arranged on the first main surface;

a sensor chip arranged on the second main surface and electrically insulated from the laminar current conductor by the printed circuit board, wherein the sensor chip is adapted to measure a current flowing through the laminar current conductor, and wherein the sensor chip comprises a magnetic field sensor; and

wherein the sensor chip is hermetically sealed between a mold material and the printed circuit board, or wherein the sensor chip is hermetically sealed within the printed circuit board.

2. The sensor package of claim 1, wherein the magnetic field sensor is adapted to produce a signal proportional to an intensity of the current flowing through the current conductor, and wherein the sensor package further comprises:

an evaluation unit adapted to determine an output signal of the sensor chip representing a measure of the intensity of the current flowing through the current conductor based on the signal of the magnetic field sensor and a calibration information.

3. The sensor package of claim 2, wherein the calibration information accounts for position tolerances between the current conductor and the magnetic field sensor.

4. The sensor package of claim 1, wherein the sensor package further comprises:

a discrete circuit element coupled between a pin of the sensor chip and an external contact of the sensor package, wherein the discrete circuit element comprises only material with a relative permeability of less than 1.1, or wherein the discrete circuit element is arranged spaced apart from the magnetic field sensor by at least 1.5 mm in case the discrete circuit element comprises material with a relative permeability of 1.1 or more.

5. The sensor package of claim 4, wherein the sensor package does not comprise any discrete circuit element with a relative permeability of more than 1.1 that is arranged in a distance smaller than 1.5 mm to any magnetic field sensor element of the sensor chip.

6. The sensor package according to claim 4, wherein the discrete circuit element is a capacitor, a fuse or a conductive lamination arranged on the printed circuit board.

7. The sensor package according to claim 1, wherein the current conductor comprises a first contact region, a second contact region and a magnetic field producing region electrically coupled between the first and the second contact region.

8. The sensor package according to claim 7, wherein the magnetic field producing region has a vertical dimension, which is vertical relative to the first main surface of the printed circuit board, and wherein the vertical dimension of the magnetic field producing region is larger than a vertical distance between the magnetic field sensor and a surface of the current conductor facing the printed circuit board.

9. The sensor package according to claim 8, wherein the vertical dimension of the magnetic field producing region is more than 1.5 times larger than the vertical distance between the magnetic field sensor and the surface of the current conductor.

10. The sensor package according to claim 8, wherein the vertical distance between the magnetic field sensor and the current conductor is larger than 50 μ

m and a vertical dimension of the current conductor is larger than 100 μ

m.

11. The sensor package according to claim 8, wherein the current conductor is electrically insulated from the sensor chip by both:

an insulating area of the printed circuit board arranged between the sensor chip and the current conductor, and an additional insulating layer arranged between the sensor chip and the current conductor.

12. The sensor package according to claim 1, wherein the sensor chip is at least partially embedded in the printed circuit board.

13. The sensor package according to claim 7, wherein a maximum lateral dimension of the magnetic field producing region parallel to the first main surface of the printed circuit board and vertical to a main current flow direction of the magnetic field producing region is larger than a maximum vertical dimension of the magnetic field producing region vertical to the first main surface of the printed circuit board.

14. The sensor package according to claim 13, wherein the maximum lateral dimension of the magnetic field producing region is more than five times larger than the maximum vertical dimension of the magnetic field producing region vertical to the first main surface of the printed circuit board.

15. The sensor package according to claim 7, wherein the magnetic field producing region comprises at least one lateral notch, and wherein the magnetic field sensor is arranged above the lateral notch and aligned to the lateral notch.

16. The sensor package according to claim 7, wherein the sensor chip is adapted to measure intensities of currents in a range of 20 A to 500 A, wherein an internal resistance of the first contact region, of the second contact region and of the magnetic field producing region is in a range between 20 μ

mOhm to 3 mOhm, and wherein a lateral area of the magnetic field producing region is larger than a lateral area of a main surface of the sensor chip.

17. A sensor package, comprising:

a printed circuit board that includes a first main surface and a second main surface, wherein the second main surface is opposite to the first main surface;

a laminar current conductor arranged on the first main surface and adapted to carry a current having a current intensity;

a sensor chip arranged on the second main surface and electrically insulated from the laminar current conductor by the printed circuit board, wherein the sensor chip comprises;

a magnetic field sensor adapted to produce a signal proportional to the current intensity; and

an evaluation unit adapted to evaluate the current intensity based on both the signal of the magnetic field sensor and individual calibration data, wherein the individual calibration data is individual for individual sensor packages; and

wherein the sensor chip is hermetically sealed between a mold material and the printed circuit board, or wherein the sensor chip is hermetically sealed within the printed circuit board.

18. The sensor package according to claim 17, wherein the laminar current conductor comprises a first contact region, a second contact region and a magnetic field producing region electrically coupled between the first and the second contact region, and wherein a vertical dimension of the magnetic field producing region vertical to the first main surface of the printed circuit board is larger than a vertical distance vertical to the first main surface of the printed circuit board between a surface of the current conductor facing towards the sensor chip and the magnetic field sensor.

19. A method for producing a sensor package, the method comprising:

providing a printed circuit board with a laminar current conductor arranged on a first main surface of the printed circuit board;

providing a sensor chip adapted to measure a current flowing through the laminar current conductor, wherein the sensor chip comprises a magnetic field sensor;

arranging the sensor chip on a second main surface of the printed circuit board opposite to the first main surface such that the sensor chip is electrically insulated by the printed circuit board from the current conductor; and

hermetically sealing the sensor chip between a mold material and a printed circuit board;

or

arranging a sensor chip in the printed circuit board such that the sensor chip is electrically insulated by the printed circuit board from the current conductor and such that the sensor chip is hermetically sealed.

20. The method according to claim 19, wherein the arranging of the sensor chip on the second main surface of the printed circuit board is performed using alignment structures or alignment marks arranged on the second main surface.

21. The method according to claim 19, wherein the sensor chip is produced in a printed circuit board panel comprising a plurality of sensor chips and one or all of the steps of the method for producing are performed with the sensor chip arranged in the printed circuit board panel.

22. The method according to claim 21, wherein the sensor chip is isolated from the printed circuit board panel by punching or snapping.

23. The method according to claim 21, wherein the sensor package is isolated from the printed circuit board panel after an end-of-line test, and wherein the sensor chip is tested individually from other sensor chips of the printed circuit board panel before isolating the sensor package from the printed circuit board panel.

24. The method according to claim 19, wherein the sensor package is calibrated after packaging the sensor package.