EP-4735903-A1 - FAST INSPECTION OF DEVICE UNDER TEST

EP4735903A1EP 4735903 A1EP4735903 A1EP 4735903A1EP-4735903-A1

Abstract

An example method to test a collection of individual devices of a device under test (DUT) uses a test tool having probes and includes sequentially testing multiple pluralities of individual devices while the probes remain in physical contact with the DUT by moving the probes and/or the DUT while maintaining physical contact between the probes and the DUT, where the moving brings, for each successive plurality, the probes (i) into parallel electrical contact with a set of contacts associated with the plurality to drive their parallel electrical excitation, then (ii) out of electrical contact with the set of contacts. Another example method electrically couples a power source to probes positioned at a first side of a DUT and a conductive surface positioned at a second side of the DUT, then controllably electrically excites a plurality of individual devices by applying an alternating voltage to the probes relative to the conductive surface.

Inventors

LEWIS, David Judah
DEKHTER, Rina
MAAYAN, ERAN
DADOOSH, Ori
IGNATOV, ANDREY
KROL, ALEXANDER
HUANG, Baoting
GRESERMAN, Alexander
COHEN, Eyal Fabrice
YOHAI, YUVAL

Assignees

InZiv Ltd.

Dates

Publication Date: 20260506
Application Date: 20240103

Claims (15)

1. A method for testing a collection of individual devices of a device under test (DUT), the method using a test tool comprising a plurality of probes, the method comprising: sequentially testing multiple pluralities of individual devices, of the collection of individual devices, while the plurality of probes remains in physical contact with the DUT, the sequentially testing comprising: moving at least one of the plurality of probes or the DUT while maintaining physical contact between the plurality of probes and the DUT, wherein the moving brings, for each successive plurality of the multiple pluralities of individual devices, the plurality of probes (i) into parallel electrical contact with a set of contacts associated with the plurality of individual devices to drive parallel electrical excitation of the plurality of individual devices, then (ii) out of electrical contact with the set of contacts associated with the plurality of individual devices; and detecting signals emitted from each plurality of individual devices of the multiple pluralities of individual devices based on the electrical excitation thereof.
2. The method of claim 1, wherein each probe of the plurality of probes comprises a flexible probe end that flexes on physical contact with the DUT.
3. The method of claim 2, wherein the moving moves the plurality of probes over a surface of the DUT having variation in flatness corresponding to the collection of individual devices, wherein the plurality of probes flex and maintain physical contact with the DUT while moving over the collection of individual devices.
4. The method of claim 1, wherein the driving imposes a voltage or current, via the plurality of probes, to the set of contacts into which the plurality of probes is in contact to drive the parallel electrical excitation of the plurality of individual devices associated with the set of contacts.
5. The method of claim 4, wherein each probe of the plurality probes comprises a respective individual electrical channel to selectively excite a respective individual device of the plurality of individual devices.
6. The method of claim 5, wherein a first individual electrical channel of a first probe of the plurality of probes provides a voltage or current level that is different from a voltage or current level provided by a second individual electrical channel of a second probe of the plurality of probes.
7. The method of claim 1, wherein a probe of the plurality of probes is a conductive plane that, for each plurality of individual devices of the multiple pluralities of individual devices, comes into simultaneous electrical contact with two or more contacts of the set of contacts associated with the plurality of individual devices, and drives parallel electrical excitation of two or more individual devices of the plurality of individual devices associated with the two or more contacts.
8. The method of claim 1, further comprising synchronizing, with the moving, a trigger to a detection system performing the detecting, the synchronizing selectively and sequentially enabling and disabling detection of the signals to coincide with sequential excitation of the multiple pluralities of individual devices.
9. The method of claim 1, wherein the moving moves the plurality of probes across the DUT with a continuous movement and consistent speed.
10. The method of claim 1, wherein the individual devices are micro lightemitting diode (microLED) devices.
11. A method for testing a collection of individual devices of a device under test (DUT), the method using a test tool comprising a plurality of probes, the method comprising: electrically coupling a power source to (i) the plurality of probes positioned at a first side of the DUT and (ii) a conductive surface positioned at a second side of the DUT; controllably electrically exciting a plurality of individual devices, of the collection of individual devices, by applying an alternating voltage to the plurality of probes relative to the conductive surface, wherein non-conductive material is disposed between (i) at least one of the conductive surface or the plurality of probes and (ii) respective electrical contacts associated with the plurality of individual devices; and detecting signals emitted from the plurality of individual devices based on the electrical excitation thereof.
12. The method of claim 11, wherein the plurality of individual devices is a first plurality of the individual devices of the collection of individual devices and the plurality of probes electrically excite the first plurality of individual devices, and wherein the method further comprises: moving at least one of the plurality of probes or the DUT, wherein the moving electrically excites a next plurality of individual devices of the collection of individual devices; detecting signals emitted from the next plurality of individual devices based on the electrical excitation thereof; and repeating, one or more times, the moving and the detecting for a respective one or more additional plurality of individual devices.
13. The method of claim 11, wherein the plurality of individual devices is a first plurality of the individual devices of the collection of individual devices, wherein the plurality of probes is in physical contact with the DUT, and wherein the method further comprises: moving at least one of the plurality of probes or the DUT while maintaining the physical contact between the plurality of probes and the DUT, wherein the moving electrically excites a next plurality of individual devices of the collection of individual devices; detecting signals emitted from the next plurality of individual devices based on the electrical excitation thereof; and repeating, one or more times, the moving and the detecting for each of one or more additional plurality of individual devices.
14. The method of claim 11, wherein the conductive surface is transparent and wherein the detecting is performed from the second side of the DUT based on the signals passing through the transparent conductive surface.
15. The method of claim 11, wherein the DUT comprises a non-conductive layer over the individual devices, wherein the plurality of probes comprises flexible probe ends that flex on physical contact with the non-conductive layer of the DUT.

Description

FAST INSPECTION OF DEVICE UNDER TEST BACKGROUND [0001] Devices such as electronic, optoelectronic, electromechanical and other types of devices can be inspected and tested. An example testing modality is electrical excitation of a device, which imposes a voltage or current to a contact that is in electrical communication with the device. Typically, in this example, the device and the contact are part of the same circuit, and the imposition of the current/voltage is to drive excitation of the device to produce a variety of signals, such as emission values. These may then be monitored or sensed optically and/or electrically and recorded for analysis. A device subjected to such testing may be referred to as a device under test (DUT). SUMMARY [0002] Shortcomings of the prior art are overcome and additional advantages are provided through the provision of a method for testing a collection of individual devices of a device under test (DUT). The method uses a test tool that includes a plurality of probes, and the method includes sequentially testing multiple pluralities of individual devices, of the collection of individual devices, while the plurality of probes remains in physical contact with the DUT. The sequentially testing includes moving at least one of the plurality of probes or the DUT while maintaining physical contact between the plurality of probes and the DUT, where the moving brings, for each successive plurality of the multiple pluralities of individual devices, the plurality of probes (i) into parallel electrical contact with a set of contacts associated with the plurality of individual devices to drive parallel electrical excitation of the plurality of individual devices, then (ii) out of electrical contact with the set of contacts associated with the plurality of individual devices. The method additionally includes detecting signals emitted from each plurality of individual devices of the multiple pluralities of individual devices based on the electrical excitation thereof. [0003] In some embodiments, the individual devices are micro light-emitting diode (microLED) devices. [0004] In some embodiments, the moving moves the plurality of probes across the DUT with a continuous movement and consistent speed. [0005] In some embodiments, each probe of the plurality of probes includes a flexible probe end that flexes on physical contact with the DUT. The moving can move the plurality of probes over a surface of the DUT having variation in flatness corresponding to the collection of individual devices, and the plurality of probes can flex and maintain physical contact with the DUT while moving over the collection of individual devices. [0006] In some embodiments, the driving imposes a voltage or current, via the plurality of probes, to the set of contacts into which the plurality of probes is in contact to drive the parallel electrical excitation of the plurality of individual devices associated with the set of contacts. In some embodiments, each probe of the plurality probes includes a respective individual electrical channel to selectively excite a respective individual device of the plurality individual devices. A first individual electrical channel of a first probe of the plurality of probes could therefore provide a voltage or current level that is different from a voltage or current level provided by a second individual electrical channel of a second probe of the plurality of probes. [0007] In some embodiments, a probe of the plurality of probes is a conductive plane that, for each plurality of individual devices of the multiple pluralities of individual devices, comes into simultaneous electrical contact with two or more contacts of the set of contacts associated with the plurality of individual devices, and drives parallel electrical excitation of two or more individual devices of the plurality of individual devices associated with the two or more contacts. [0008] In some embodiments, the method further includes synchronizing, with the moving, a trigger to a detection system performing the detecting, the synchronizing selectively and sequentially enabling and disabling detection of the signals to coincide with sequential excitation of the multiple pluralities of individual devices. [0009] In another aspect, a method is provided for testing a collection of individual devices of a DUT and uses a test tool that includes a plurality of probes, and the method includes electrically coupling a power source to (i) the plurality of probes positioned at a first side of the DUT and (ii) a conductive surface positioned at a second side of the DUT, controllably electrically exciting a plurality of individual devices, of the collection of individual devices, by applying an alternating voltage to the plurality of probes relative to the conductive surface, where non-conductive material is disposed between (i) at least one of the conductive surface or the plurality of probes and (ii) respective electrical cont