Multi-site concurrent wafer probe magnetic circuit testing

Patent metadata

Field	Value
Publication number	US-11927604-B2
Application number	US-202117313657-A
Country	US
Kind code	B2
Filing date	May 6, 2021
Priority date	May 15, 2020
Publication date	Mar 12, 2024
Grant date	Mar 12, 2024

Abstract

A wafer probe test system having a probe card with a probe head, a rotary magnet, a magnetic sensor positioned to sense the magnetic field of the rotary magnet and a controller coupled to the probe card, where the probe head has probe needles to engage features of test sites of a wafer in a wafer plane of orthogonal first and second directions, and the rotary magnet is rotatable around an axis of a third direction to provide a magnetic field to the wafer, in which the controller includes a model of magnetic flux density in the first, second and third directions at the respective test sites of the wafer as a function of a rotational angle of the rotary magnet, a probe needle height along the third direction and a measured magnetic flux density of the magnetic sensor.

First claim

What is claimed is:

1. A method of manufacturing an electronic device, the method comprising:
initializing a wafer probe test system to test a wafer that is positioned in a wafer plane of orthogonal first and second directions, including:
measuring a probe needle height along a third direction that is orthogonal to the first and second directions, and
using a magnetic sensor of the wafer probe test system, measuring a magnetic field of a rotary magnet rotating about an axis along the third direction at different rotational angles; and

while the rotary magnet rotates, testing magnetic sensing performance of circuits of respective test sites of the wafer according to a model of magnetic flux density in the first, second and third directions at the respective test sites of the wafer as a function of the rotational angle of the rotary magnet, the probe needle height and measured magnetic flux density of the magnetic sensor.

2. The method of claim 1 , wherein:
initializing a wafer probe test system further comprises determining an angular offset for respective angular regions of the rotation of the rotary magnet; and
the magnetic sensing performance of the circuits of respective test sites of the wafer is tested according to the model, the probe needle height, the measured magnetic flux density of the magnetic sensor, and the angular offset.

3. The method of claim 2 , wherein testing the magnetic sensing performance of circuits of respective test sites of the wafer comprises determining a pass or fail condition of the circuits of the respective test sites of the wafer according to respective toggle angles at which the respective circuits switch from a first state to a second state in response to the magnetic field of the rotary magnet.

4. The method of claim 1 , wherein testing the magnetic sensing performance of circuits of respective test sites of the wafer comprises determining a pass or fail condition of the circuits of the respective test sites of the wafer according to respective toggle angles at which the respective circuits switch from a first state to a second state in response to the magnetic field of the rotary magnet.

5. The method of claim 1 , further comprising:
modeling magnetic flux density at the test sites of the wafer and the magnetic sensor of the wafer probe test system of a nominal design and setup variations of the rotary magnet rotating about the axis at the respective different rotational angles; and
developing the model of magnetic flux density in the first, second and third directions at the respective test sites of the wafer as a function of the rotational angle of the rotary magnet, the probe needle height and the measured magnetic flux density of the magnetic sensor according to the modeling of the magnetic flux density at the test sites of the wafer and the magnetic sensor of the wafer probe test system.

6. The method of claim 5 , wherein the model is developed as a regression model of magnetic flux density at the test sites of the wafer.

7. The method of claim 5 , wherein modeling magnetic flux density at the test sites of the wafer and the magnetic sensor of the wafer probe test system includes using a three-dimensional solver to model the magnetic flux density at the test sites of the wafer and the magnetic sensor of the wafer probe test system of the nominal design and the setup variations.

8. The method of claim 1 , further comprising:
controlling a current flowing in a band coil having turns in a plane of the first and second directions to generate a magnetic field in the third direction that cancels a magnetic field of the rotary magnet in the third direction.

9. A method of manufacturing an electronic device, the method comprising:
initializing a wafer probe test system to test a wafer that is positioned in a wafer plane of orthogonal first and second directions, including:
measuring a probe needle height along a third direction that is orthogonal to the first and second directions,
using a magnetic sensor of the wafer probe test system, measuring a magnetic field of a rotary magnet rotating about an axis along the third direction at different rotational angles;
calculating a multiplier factor as a ratio between modeling data and measured magnetic flux density of the magnetic sensor at the respective different rotational angles; and
determining an angular offset for respective angular regions of the rotation of the rotary magnet; and

while the rotary magnet rotates, testing magnetic sensing performance of circuits of respective test sites of the wafer according to a model of magnetic flux density in the first, second and third directions at the respective test sites of the wafer as a function of the rotational angle of the rotary magnet, the probe needle height and the measured magnetic flux density of the magnetic sensor, and the angular offset;
wherein the model of magnetic flux density at the test sites of the wafer is a regression model having model parameters for magnetic flux density in the first, second and third directions as a function of the rotational angle of the rotary magnet for each of the respective test sites of the wafer; and
wherein testing the magnetic sensing performance of the circuits of the respective test sites of the wafer comprises calculating magnetic flux density at the respective test sites of the wafer as a function of the rotational angle of the rotary magnet, the probe needle height, the measured magnetic flux density of the magnetic sensor, the angular offset and the multiplier factor.

10. The method of claim 9 , wherein testing the magnetic sensing performance of circuits of respective test sites of the wafer comprises determining a pass or fail condition of the circuits of the respective test sites of the wafer according to respective toggle angles at which the respective circuits switch from a first state to a second state in response to the magnetic field of the rotary magnet.

11. A method of manufacturing a packaged electronic device, the method comprising:
fabricating circuits on or in respective test sites of a wafer;
wafer probe testing the test sites of the wafer, including:
initializing a wafer probe test system to test the wafer that is positioned in a wafer plane of orthogonal first and second directions, including:
measuring a probe needle height along a third direction that is orthogonal to the first and second directions, and
using a magnetic sensor of the wafer probe test system, measuring a magnetic field of a rotary magnet rotating about an axis along the third direction at different rotational angles; and

while the rotary magnet rotates, testing magnetic sensing performance of the circuits of the respective test sites of the wafer according to a model of magnetic flux density in the first, second and third directions at the respective test sites of the wafer as a function of the rotational angle of the rotary magnet, the probe needle height and the measured magnetic flux density of the magnetic sensor;

separating the respective test sites from one another to provide separated semiconductor dies; and
packaging at least some of the separated semiconductor dies to form packaged electronic devices.

12. The method of claim 11 , wherein testing the magnetic sensing performance of the circuits of the respective test sites of the wafer comprises determining a pass or fail condition of the circuits of the respective test sites of the wafer according to respective toggle angles at which the respective circuits switch from a first state to a second state in response to the magnetic field of the rotary magnet.

13. The method of claim 11 , wherein:
initiali

Assignees

• Texas Instruments Inc

Inventors

• Huang Xinkun
• Lee Dok Won
• Ledbetter Christopher Michael
• Dahl Bret Alan
• Solomon Roy Deidrick

Classifications

• G01R1/07342 Primary

  the body of the probe being at an angle other than perpendicular to test object, e.g. probe card · CPC title

• G01R1/0491

  for testing integrated circuits on wafers, e.g. wafer-level test cartridge · CPC title

• G01R33/072

  Constructional adaptation of the sensor to specific applications · CPC title

• G01R33/12 Primary

  Measuring magnetic properties of articles or specimens of solids or fluids (involving magnetic resonance G01R33/20) · CPC title

• G01R33/07

  Hall effect devices · CPC title