Sensor chip and associated calibration lead frame

Patent metadata

Field	Value
Publication number	US-11243270-B2
Application number	US-202016931839-A
Country	US
Kind code	B2
Filing date	Jul 17, 2020
Priority date	Jul 22, 2019
Publication date	Feb 8, 2022
Grant date	Feb 8, 2022

Abstract

A packaged sensor chip includes a lead frame to which there is attached a sensor element designed to generate a sensor signal that depends on a magnetic field to which the sensor element is exposed; and a package therefor, wherein the lead frame has function terminals and wherein the lead frame has at least two calibration terminals that are arranged on two other opposing sides of the package, wherein the lead frame has conductive structures that connect the at least two calibration terminals, wherein the conductive structures are structured so as to generate a calibration magnetic field for the sensor element when a current flows through them, and wherein the conductive structures are part of a connection structure that connects a plurality of lead frames before the plurality of lead frames are disconnected from one another in a first direction in which the other two sides are opposite one another.

First claim

What is claimed is:

1. A packaged sensor chip, comprising:
a sensor element that is configured to generate a sensor signal that depends on a magnetic field to which the sensor element is exposed;
a lead frame to which the sensor element is attached; and
a package that packages the sensor element and the lead frame,
wherein the lead frame has function terminals that are arranged on at least one of two first opposing sides of the package,
wherein the lead frame has at least two calibration terminals that are arranged on two second opposing sides of the package,
wherein the lead frame has conductive structures that connect the at least two calibration terminals, wherein the conductive structures are structured so as to generate a calibration magnetic field for the sensor element when a current flows through the conductive structures, and
wherein the conductive structures are part of a connection structure that connects a plurality of lead frames before the plurality of lead frames are singulated from one another in a first direction, the direction of which the two second opposing sides are opposite one another.

2. The packaged sensor chip as claimed in claim 1 , wherein:
the sensor element is galvanically connected to at least one of the function terminals.

3. The packaged sensor chip as claimed in claim 1 , wherein:
the conductive structures and the at least two calibration terminals are galvanically isolated from the function terminals.

4. The packaged sensor chip as claimed in claim 3 , wherein:
at least two of the conductive structures and their associated calibration terminals are galvanically isolated from one another.

5. The packaged sensor chip as claimed in claim 1 , wherein:
at least one first conductive structure of the conductive structures extends in a straight line in the first direction, and
at least one second conductive structure of the conductive structures extends perpendicular to the first direction.

6. The packaged sensor chip as claimed in claim 1 , wherein:
the sensor element has a magnetic sensor.

7. The packaged sensor chip as claimed in claim 6 , wherein:
the magnetic sensor has a Hall sensor, an XMIR sensor, or an inductive sensor.

8. The packaged sensor chip as claimed in claim 1 , wherein:
the sensor chip includes at least one further sensor element that is configured so as to record a state of an environment in which the sensor chip is located.

9. The packaged sensor chip as claimed in claim 8 , wherein:
the further sensor element includes a temperature sensor.

10. The packaged sensor chip as claimed in claim 8 , wherein:
the further sensor element includes further conductive structures and further calibration terminals associated with the further conductive structures, wherein the further conductive structures are galvanically isolated from the conductive structures of the sensor element.

11. A lead frame structure, comprising:
a plurality of packaged sensor chips coupled together in a chain along a first direction, wherein each of the plurality of packaged sensor chips comprises:
a sensor element that is configured to generate a sensor signal that depends on a magnetic field to which the sensor element is exposed;
a lead frame to which the sensor element is attached; and
a package that packages the sensor element and the lead frame,
wherein the lead frame has function terminals that are arranged on at least one of two first opposing sides of the package,
wherein the lead frame has at least two calibration terminals that are arranged on two second opposing sides of the package,
wherein the lead frame has conductive structures that connect the at least two calibration terminals, wherein the conductive structures are structured so as to generate a calibration magnetic field for the sensor element when a current flows through the conductive structures, and
wherein the conductive structures are part of a connection structure that connects a plurality of lead frames before the plurality of lead frames are singulated from one another in the first direction, the direction of which the two second opposing sides are opposite one another,
wherein each of the plurality of packaged sensor chips is coupled to at least one adjacent packaged sensor chip in the first direction; and

a plurality of connecting webs, wherein the lead frames of each pair adjacent packaged sensor chips of the plurality of packaged sensor chips are connected together by at least one connecting web in the first direction,
wherein the connection structure of each lead frame comprises the conductive structures and the at least one connecting web, and
wherein the plurality of connecting webs are configured to be severed when the plurality of lead frames are singulated, such that web ends of the plurality of connecting webs remaining after the singulation form the calibration terminals.

12. The lead frame structure as claimed in claim 11 , wherein:
the web ends remaining after the singulation are configured to be bonded to the package in a form-fitting or frictional manner.

13. The lead frame structure as claimed in claim 11 , wherein:
the web ends remaining after the singulation are configured so as to be used as calibration terminals.

14. A method for manufacturing a plurality of packaged sensor chips, comprising:
providing the lead frame structure comprising a plurality of lead frames coupled together in a chain along a first direction, wherein each respective lead frame of the plurality of lead frames comprises:
function terminals that are arranged on at least one of two first opposing sides of a package that packages the respective lead frame, at least two calibration terminals that are arranged on two second opposing sides of the corresponding package, conductive structures that connect the at least two calibration terminals, and at least one connecting web,
wherein the conductive structures are structured so as to generate a calibration magnetic field for the sensor element when a current flows through the conductive structures, and
wherein the conductive structures are part of a connection structure that connects a plurality of lead frames via a plurality of connecting webs before the plurality of lead frames are singulated from one another in the first direction, the direction of which the two second opposing sides are opposite one another;

applying at least one sensor element to each respective lead frame;
packaging respective sensor elements and respective lead frames to form a plurality of packaged sensor chips coupled together in a chain along a first direction via the plurality of connecting webs;
singulating the plurality of packaged sensor chips that are coupled together by the lead frame structure; and
performing a calibration operation of applying a current to at least some of the calibration terminals before or after the plurality of packaged sensor chips are singulated.

15. The method as claimed in claim 14 , wherein:
at least one sensor element is calibrated after the plurality of packaged sensor chips have been singulated.

16. The method as claimed in claim 14 , wherein:
the calibration operation is performed before and after the plurality of packaged sensor chips are singulated.

Assignees

• Infineon Technologies Ag

Inventors

• Gillinger Manuel
• Granig Wolfgang

Classifications

• H10W74/00

  Encapsulations, e.g. protective coatings · CPC title

• H10W90/736

  between a chip and a stacked lead frame, conducting package substrate or heat sink · CPC title

• H10W70/421

  Shapes or dispositions · CPC title

• H10W70/429

  being the outer leads · CPC title

• G01R33/02

  Measuring direction or magnitude of magnetic fields or magnetic flux (G01R33/20 takes precedence) · CPC title