EP-4737913-A1 - HIGH-SPEED DIGITAL TESTING ON CIRCUIT BOARDS USING MODIFIED RF TESTERS

Abstract

In various embodiments, a method comprises positioning, by a testing probe module, a probe head relative to a location of a device under test, wherein the probe head and the testing probe module are included in a test device, acquiring, by a borescope included in the test device, an image of a probe head location relative to the location of the device under test, and contacting, by the probe head, the location on the device under test.

Inventors

• FURNITUREWALA, QUAID JOHER
• LAI, Henry Wah
• LATHROP, Matthew Macneill
• DEHKORDI, Karim
• PARASCHIV, Bogdan
• NIE, Wing Lai
• YU, XIN
• WU, Wan Sheng
• SHIN, Jeremy Nicholas

Assignees

• R&D Circuits
• Acculogic Inc.

Dates

Publication Date

20260506

Application Date

20251008

Claims (15)

1. A method comprising: positioning, by a testing probe module, a probe head relative to a location of a device under test, wherein the probe head and the testing probe module are included in a test device; acquiring, by a borescope included in the test device, an image of a probe head location relative to the location of the device under test; and contacting, by the probe head, the location on the device under test.
2. The method of claim 1, further comprising: transmitting the image to a calibration module for optical calibration of the probe head.
3. The method of claim 2, further comprising: performing, by the calibration module, short-open-load-through (SOLT)-based calibration for electrical radio frequency calibration of the testing probe module.
4. The method of either claim 2 or claim 3, wherein the testing probe module further includes a plurality of phase matched ultralow loss cables that connect the probe head to the calibration module.
5. The method of any one of the previous claims, wherein the testing probe module further includes an illumination device coupled to the probe head and the borescope.
6. The method of any one of the previous claims, wherein the borescope acquires the image in a Z-direction relative to the device under test and the probe head.
7. The method of any one of the previous claims, further comprising: acquiring, by a force sensor, a force measurement when the probe head contacts the location on the device under test, wherein the force sensor is included in the test device; and transmitting the force measurement to a calibration module, wherein the force measurement is usable by the calibration module to generate a command for the testing probe module to move the probe head.
8. The method of any one of the previous claims, wherein the test device further includes a head rotation module that controls rotation of the probe head up to 270° about a plane perpendicular to a Z-direction relative to the probe head.
9. The method of any one of the previous claims, further comprising: acquiring, by the probe head, a plurality of scattering parameter measurements upon contacting the location on the device under test; and transmitting, by the test device, the plurality of scattering parameter measurements to a vector network analysis (VNA) instrument.
10. A test device comprising: a probe head for contacting a location on a device under test; a borescope for acquiring an image of a probe head location relative to the location on the device under test; and a testing probe module for positioning the probe head relative to the location of the device under test.
11. The test device of claim 10, wherein the borescope is configured to transmit the image to a calibration module for optical calibration of the probe head, wherein preferably the calibration module is configured to further perform short-open-load-through (SOLT)-based calibration for electrical radio frequency calibration of the testing probe module.
12. The test device of claim 11, further comprising: a plurality of phase matched ultralow loss cables that connect the probe head to the calibration module.
13. The test device of any one of claims 10 to 12, wherein the borescope is configured to acquire images in a Z-direction relative to the device under test and the probe head.
14. The test device of any one of claims 10 to 13, further comprising: a force sensor that is configured to acquire a force measurement when the probe head contacts the location on the device under test, and/or wherein the probe head comprises a fixed-pitch compliant, FPC, probe, a vector network analyzer, VNA, type probe, or an air coplanar probe, ACP.
15. One or more non-transitory computer-readable media storing program instructions that, when executed by one or more processors, cause the one or more processors to perform a method comprising: positioning, by a testing probe module, a probe head relative to a location of a device under test, wherein the probe head and the testing probe module are included in a test device; acquiring, by a borescope included in the test device, an image of a probe head location relative to the location on the device under test; and contacting, by the probe head, the location on the device under test.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority benefit of United States Provisional Patent Application titled, "RF AND HIGH-SPEED DIGITAL TESTING ON CIRCUIT BOARDS USING MODIFIED RF TESTERS," filed on October 30, 2024, and having Serial No. 63/714,073. The subject matter of this related application is hereby incorporated herein by reference. BACKGROUND Field of the Various Embodiments This application relates to systems and methods for reliable test tooling for packaged integrated circuits (IC) devices, and more specifically, to high-speed digital testing on circuit boards using modified radio frequency (RF) testers. Description of the Related Art Currently, printed circuit boards (PCBs) operate at over a large range of operating frequencies. Due to operation at such frequencies, PCBs are thus subject to degradation in quality due to irregularities such as discontinuities in impedance, impairments of inductance, impairments in capacitance, or back drilling effects. Accordingly, reliable test tooling for PCBs is necessary to detect any irregularities that are included on a given PCB assembly (PCBA). Various testing devices, such as oscilloscopes, spectrum analyzers, vector network analyzers (VNAs), signal generators, and power meters are used to perform various types of signal integrity analysis to detect irregularities within defined frequency ranges. Robotic positioning systems are mechanisms that enable precise movement and placement of test probes. These robotic positioning systems perform engineered repeatable operations, enabling consistency in testing portions of a circuit board. Various automated tester systems include multiple probes that simultaneously engage with components on a PCBA. Use of such automated testing equipment enables a tester to quickly perform multiple measurements. Automated testing equipment is designed to perform accurate, repeatable, and efficient operations and greatly speed the process of detecting any irregularities on a PCBA. At least one drawback of automated probe testers is that such systems do not accurately test PCBAs that are to be operated at high frequencies. For example, various PCBs are fabricated with various designs that are configured to operate above 5 GHz, with some designs configured to operate above 40 GHz. Many conventional automated testers include components, such as differential probes, that accurately test over a narrow band of frequencies, mainly operating below 1 GHz. Some conventional testing systems include various testing components that enable testing of a PCBA at high frequencies, such as probes, cables, and connectors that are compatible with the impedance and bandwidth being tested of frequencies above 1 GHz or 40 GHz. However, even these probes, cables, and connectors for higher frequencies require contact at a particular location of the PCBA to avoid mismeasurement of data, or to shield the circuit from external interference. Conventional testing systems, though, do not currently provide the requisite precise control of probes to contact specific locations of a PCBA with a specific force. Instead, the necessary control of probes needed for high frequencies requires manual intervention and is thus time-consuming for the tester. For example, manual RF testing for a circuit board with only 100 components at high frequencies would take days for a tester to properly test. In view of the foregoing, what is needed in the art is an automated technique to perform testing on circuit boards at high frequencies. SUMMARY In various embodiments, a method comprises positioning, by a testing probe module, a probe head relative to a location of a device under test, where the probe head and the testing probe module are included in a test device, acquiring, by a borescope included in the test device, an image of a probe head location relative to the location of the device under test, and contacting, by the probe head, the location on the device under test. At least one technical advantage of the disclosed techniques relative to the prior art is that, with the disclosed testing device, automated testing systems can acquire electrical measurements related to the operation of components of a printed circuit board assembly when operating at high frequencies. In particular, by using the disclosed techniques to validate the landing of a probe head on a location of the printed circuit board assembly, the probe testing module can automatically calibrate and confirm a proper connection between the probe testing module and components of the circuit board assembly before acquiring the electrical measurements. Consequently, automated testing systems can thus accurately test printed circuit board assemblies at high frequencies and minimize manual intervention. Further, the disclosed techniques can control the contact impedance transition between the probe head and the printed circuit board assembly to minimize signal degradation test signals at hi