WO2006059259A1

WO2006059259A1 - Wireless probe system

Info

Publication number: WO2006059259A1
Application number: PCT/IB2005/053872
Authority: WO
Inventors: Brian D. Logsdon
Original assignee: Koninklijke Philips Electronics, N.V.
Priority date: 2004-11-30
Filing date: 2005-11-22
Publication date: 2006-06-08

Abstract

A tester and a device under test (DUT), which are remote from each other, are wirelessly communicatively coupled by a remote probe 200 removably attached to the DUT, and a probe adapter 100 removably attached to the tester. The probe adapter 100 provides control information to the remote probe 200 for adjusting electrical characteristics thereof, and the control information may be provided in a manner that is independent of the tester, or under the direct control of the tester. The remote probe 200 obtains data from the DUT and transmits this data, by means of any suitable protocol, to the probe adapter 100, which then provides the data to the tester. The remote probe 200 may contact one or more electrical nodes of the DUT, and may simultaneously, or in a predetermined time order, obtain data from those nodes. The tester may provide, via the probe adapter 100 and the remote probe 100, electrical stimuli to the DUT.

Description

WIRELESS PROBE SYSTEM

The present invention relates generally to communication between a tester and a remotely located device under test, and more particularly relates to wireless communication between such a tester and device under test.

Advances in semiconductor manufacturing technology have resulted in very highly integrated circuits, which contain millions of transistors, along with various other components and interconnections. The integrated circuits that result from the aforementioned advances provide significant electronic functionality at relatively low costs. Such advances have been incorporated into both digital and analog integrated circuits. It is well-known that such integrated circuits, as well as the systems formed with these integrated circuits, require testing and measurement. In order to perform such testing and measurement, one or more connections are made between the device or system under test, and one or more pieces of test equipment. Conventional electronic test equipment utilizes a combination of high-performance electronics and a set of wires, often referred to as "probes", to pass the electrical signals between the device or system under test and the test equipment. As the operational characteristics of modern devices and systems have increased to the Gigahertz range, the aforementioned probe wires have become shorter, more sensitive to variation, and more expensive.

One disadvantage of the current state of the art in this arena is the proximity within which the test equipment must be located relative to the device or system being tested. In most cases, probe leads are now less than one meter long. Organizing a laboratory, or field maintenance environment, that can efficiently operate within these physical constraints can be difficult, if not impossible. Furthermore, with the increasing cost of test equipment, flexibility and relocation are major considerations.

Another consideration with respect to testing and measurement of devices and systems is signal integrity and performance. As signal frequencies increase, the cost and complexity of the probes increase as well. Additionally, many of the issues encountered in the lab environment are subject to electrical interference, errors due to impedance mismatches, and other error sources.

What is needed are methods and apparatus for coupling test and measurement equipment to various devices, or systems, under test, while simultaneously satisfying the constraints of maintaining short probe wires; and allowing large physical separation between the test and measurement equipment and the devices or systems under test.

Briefly, a device under test (DUT) and a tester, which are remote from each other, are wirelessly communicatively coupled by a remote probe physically coupled to the DUT, and a probe adapter physically coupled to the tester. The probe adapter provides control information to the remote probe for adjusting electrical characteristics thereof, and the control information may be provided in a manner that is independent of the tester, or under the direct control of the tester. The remote probe obtains data from the DUT and transmits this data, by means of any suitable protocol, to the probe adapter, which then provides the data to the tester. The remote probe may contact one or more electrical nodes of the DUT, and may simultaneously, or in a predetermined time order, obtain data from those nodes. The tester may provide, via the probe adapter and the remote probe, electrical stimuli to one or more nodes of the DUT.

In a still further aspect of the present invention, a probe adapter may communicate with a plurality of remote probes.

In a still further aspect of the present invention, a remote probe may communicate with a plurality of probe adapters.

Fig. 1 is a schematic block diagram of a receiver channel of an illustrative probe adapter that is coupled to test equipment. Fig. 2 is a schematic block diagram of a transmitter channel of an illustrative remote probe that is coupled to a device under test.

Fig. 3 is a flow diagram illustrating a method in accordance with the present invention.

Generally, the present invention relates to providing a wireless connection between a device, or system, under test, and a one or more remotely located pieces of test and/or measurement equipment.

Various embodiments of the present invention include methods to allow users of probe-based test equipment to accurately sample and display electrical data on test equipment without the need for the test equipment to be within the immediate proximity of the system being probed. A typical system in accordance with the present invention digitizes an electrical signal being tested and transmits the digital data to the test equipment using wireless technologies. Such wireless technologies may include standardized protocols including, but not limited to, Bluetooth or IEEE 802.11. Reference herein to "one embodiment", "an embodiment", or similar formulations, means that a particular feature, structure, operation, or characteristic described in connection with the embodiment, is included in at least one embodiment of the present invention. Thus, the appearances of such phrases or formulations herein are not necessarily all referring to the same embodiment. Furthermore, various particular features, structures, operations, or characteristics may be combined in any suitable manner in one or more embodiments.

A wireless probe system eliminates many of the difficulties associated with establishing and maintaining an efficient lab environment. In other words, the short probe wires required for use with high frequency signals, forces the test equipment and DUT to be physically co-located within a short distance of each other, thereby imposing constraints on the layout and organization of a lab or test area. In accordance with the present invention, the actual probe length can be held to between ten and fifteen centimeters, thereby greatly improving signal quality. With the wireless technology transporting data between the device under test and the test equipment, the signal loss and interference normally associated with longer physically signal paths (i.e., probe wires) is substantially reduced. In this way, the requirement for close physical placement, or co-location of the tester and DUT is eliminated, and therefore the test equipment can be organized in such a manner as to increase the efficiency of the user, rather than the user having to sacrifice usability and the ergonomics of the work area in order to meet the requirements of the short probe wires. A wireless probe system, in accordance with the present invention, includes two components, i.e., a wireless remote probe and a probe adapter. The probe adapter attaches to a probe interface connector on the test equipment. This interface may be a coaxial connection, as on an oscilloscope; or a multi-lead interface that might be present on a logic analyzer. The probe adapter receives digital signals from the wireless remote probe and transforms the data received into electrical signals that the corresponding specific test equipment can then process and/or display. The wireless remote probe is used to collect the signal data from the device, or system, being tested. The wireless remote probe transforms analog electrical signals into a digital format that is then transmitted to the probe adapter. The terms integrated circuit (IC), semiconductor device, monolithic device, microelectronic device, and chip are often used interchangeably in the field of electronics generally. The present invention is applicable to all the above as they are generally understood in the field. The terms test and measurement equipment refer to any type of equipment useful for measuring or monitoring one or more characteristics of a device or system under test. Such equipment includes, but is not limited to oscilloscopes, logic analyzers, spectrum analyzers, test pattern comparators, and so on. The present invention may be embodied in a wide variety of arrangements. One illustrative embodiment (Figs. 1-2) is described in the context of a single-channel oscilloscope probe. In this embodiment, a single wireless remote probe, and probe adapter are used. The probe adapter may be connected to the external probe connector on the test equipment. In such an arrangement the probe adapter is removably attachable, and any suitable connector(s) may be used. The removably attachable connection may include an electrical connector, or it may include an electrical connector and a separate mechanical attachment means for removably attaching the probe adapter to the test equipment. It is noted that in this illustrative example, a datapath is shown from the device under test through the remote probe, the probe adapter, and to the tester (i.e., oscilloscope). It will be appreciated that other embodiments of the present invention may provide a datapath for bidirectional communication between the probe adapter and the remote probe, as well as between the tester and the device under test.

In an alternative embodiment, the probe adapter may be integrated into the test equipment directly. In this embodiment, the antenna may be located at any suitable location on the test equipment.

The probe adapter typically includes two sections: a wireless data transceiver, and a signal conversion section. In operation, the wireless data transceiver transmits information (such as calibration settings, bandwidth controls, sensitivity settings, etc.) to the remote probe, and receives information (e.g., digitized data) from the remote probe. The signal conversion section of the probe adapter processes the data received from the remote probe, and transforms the received data into an analog signal or other format as may be required for the test equipment to further analyze.

Referring to Fig. 1, an illustrative wireless probe adapter 100 in accordance with the present invention is shown. Probe adapter 100 includes a signal conversion section 101, which in turn includes a digital-to-analog converter 102. In this illustrative embodiment, the probe adapter serves to substitute for a conventional oscilloscope probe. A probe connection 104 is coupled to a tester (not shown). In this example, probe connection 104 includes a center conductor 105 for carrying a signal, and a shield 107, which is coupled to ground, disposed around the center conductor. The center conductor of probe connection 104 is coupled via signal pathway 106 to signal conversion section 101. Signal conversion section 101 includes (D/A) converter 202 coupled, by means of a pathway 113, to a processing circuit 112 for signal conditioning and scaling. Although an eight bit digital input is shown in Fig. 1, it will be appreciated that the present invention may be implemented with a digital input having any number of bits. D/A converter 102 is also coupled to receive a reference voltage Vref from a reference voltage generator circuit 110. A wireless transceiver circuit, or module, 114 is coupled to processing circuit 112 of signal conversion section 101. As indicated by pathways 115 and 117 in Fig. 1, wireless transceiver module 114 is coupled to receive data from signal conversion section 101 for transmission to a remote receiver (e.g., the remote probe), and is further coupled to supply data, which has been received from a remote transmitter (e.g., the remote probe), to signal conversion section 101. Wireless transceiver module 114 typically includes an antenna 120 to facilitate transmitting and receiving. It will be appreciated that other configurations are within the scope of the present invention, such as but not limited to, having separate transmit and receive antennas.

The remote probe typically includes a wireless data transceiver and a signal conversion section. The remote probe is similar to the probe adapter in that each includes a wireless data transceiver and a signal conversion section. One difference between the probe adapter and the remote probe, in this illustrative embodiment, is that the remote probe transforms analog electrical signals into digital data prior to transmission.

Referring to Fig. 2, an illustrative wireless remote probe 200 in accordance with the present invention is shown. Remote probe 200 includes a signal conversion section 201, which in turn includes an analog-to-digital converter 202. In this illustrative embodiment, the wireless remote probe serves to substitute for a conventional oscilloscope probe. A probe 204 is coupled to a test point (not shown) of a device, or system, under test. In this example, probe 204 include a center conductor for carrying a signal, and a shield, which is coupled to ground, disposed around the center conductor. The center conductor of probe 204 is coupled via signal pathway 206 to a signal conversion section 201. Signal conversion section 201 includes an analog-to-digital (AfO) converter 202 coupled, by means of a pathway 213, to a processing circuit 212 for signal conditioning and scaling. Although an eight bit digital output is shown in Fig. 2, it will be appreciated that the present invention may be implemented with a digital output having any number of bits. A/D converter 202 is also coupled to receive a reference voltage Vref from a reference voltage generator circuit 210. A wireless transceiver circuit, or module, 214 is coupled to processing circuit 212 of signal conversion section 201. As indicated by pathways 215 and 217 in Fig. 2, wireless transceiver module 214 is coupled to receive data from signal conversion section 201 for transmission to a remote receiver (e.g., the probe adapter), and is further coupled to supply data, which has been received from a remote transmitter (e.g., the probe adapter), to signal conversion section 201. Wireless transceiver module 214 typically includes an antenna 220 to facilitate transmitting and receiving. It will be appreciated that the present invention is not limited to the functional partitions of this illustrative embodiment, but rather any suitable arrangement of these functions may be used. For example, the function of packetizing and/or encapsulating data for transmission may be performed within wireless transceiver module 214, or this function may be performed within a different block of circuitry.

It will be appreciated that a remote probe in accordance with the present invention may be constructed without an A/D converter for those cases wherein digital data is being read directly from the DUT.

In an alternative embodiment wherein the remote probe is adapted to be used for wafer level testing of integrated circuits, the remote probe may receive one or more inputs from the wafer prober, in addition to inputs from a DUT. For example, the remote probe may receive a signal indicating that a wafer is available for testing and has been properly aligned with a probe card. Similarly, the remote probe may receive a signal from the wafer prober indicating which die of the wafer is currently being tested. The die location information may be sent to the remotely located tester, by remote probe via the probe adapter, so that the tester can track yield as a function of die location on the wafer. In this illustrative embodiment, the remote probe is adapted to make electrical contact with the probe card.

In a further alternative embodiment, the remote probe is adapted to be used for burn- in testing. That is, a DUT is placed in an oven, or similar environmental chamber in which the ambient temperature may be controlled, and the remote probe may transmit data from a DUT operating in an elevated temperature environment. In one embodiment the remote probe may be coupled to the DUT and both the DUT and remote probe are disposed in the environmental chamber. In an alternative embodiment the DUT is disposed in the environmental chamber, the remote probe is disposed outside the environmental chamber, and the two are coupled to each other by a physical wired connection through the environmental chamber.

Various embodiments of the present invention may include additional features suitable for adjusting characteristics including but not limited to probe sensitivity, calibration settings, and offsets. The probe itself, in this illustrative embodiment, may be used in the same manner as it is currently, thereby facilitating the adoption of wireless remote probe systems in accordance with the present invention.

It is noted that a remote probe in accordance with the present invention may be a hand-held unit, or it may be implemented as a unit that is adapted to clip-on, or otherwise removably attach to, one or more test points of a device, or system, under test, such that at least one test point is in electrical contact with a signal carrying conductor of the remote probe.

It is noted that a remote probe in accordance with the present invention may include two or more signal carrying conductors through which two or more test points may be simultaneously monitored. Alternatively, the two or more test points may be sampled at predetermined times.

In one embodiment of the present invention, the remote probe, in addition to obtaining information from the DUT, may also inject, or provide, an input stimulus pattern to the DUT. In other words, it may be necessary or desirable, for the remote probe to actively provide one or more signals to the DUT. Such input signals, or patterns, may be specified by the remotely located tester, and communicated to the remote probe via the probe adapter.

As noted above, the communication between the probe adapter and the remote probe may be in any suitable protocol. Furthermore, communications between the probe adapter and the remote probe may be encrypted. Any suitable encryption scheme may be used. It is further noted that the data to be communicated between the remote probe and the probe adapter may be compressed prior to transmission. Generally, a lossless compression scheme is preferred, but is not required by the present invention.

In one embodiment of the present invention, a single remote probe may communicate with a plurality of probe adapters. In this way, a variety of test or analysis functions may be performed. By way of example and not limitation, a remote probe that is in contact with an operating DUT may selectively communicate data to a first probe adapter coupled to a first piece of test equipment, and to a second probe adapter coupled to a second piece of test equipment. It will be appreciated that a remote probe may communicate with more than two probe adapters. Such selective communication can be accomplished in a number of ways, such as but not limited to, the establishment of a wireless network in which the remote probe and each probe adapter has an address, and that address is used to direct the data to a particular destination. In another embodiment of the present invention, a single probe adapter may communicate with a plurality of probe adapters. In this way, a plurality of DUTs may be tested by a single remotely located tester. As noted above, such communication may be facilitated by assigning an address to each of the remote probes so that incoming data packets can be associated with specific DUTs. In an environment, such as a lab or test area, where sensitive data is being wirelessly communicated between a device under test and a tester, there may be a concern regarding the leakage of radiated information outside of the lab or test area where the confidentiality of such information may be compromised. In other words the RF signal may picked up by an external receiver operated by potential eavesdropper. An example of the transmission of confidential information is where the contents of a microcode ROM on an integrated are being read out and wirelessly transmitted from the remote probe to a probe adapter. In such a case, the lab or test area may be shielded to prevent undesired leakage of the confidential information to regions that are outside of the lab or test area. The shielding may be used in addition to, or in lieu of, an encryption scheme. Referring to Fig. 3, a method in accordance with the present invention is described.

More particularly, a method of interfacing with a device under test and communicating data therefrom to a remotely located tester, and for transmitting control information from the remotely located tester to the interface with the device under test, includes coupling 302 a probe adapter to the tester; coupling 304 a remote probe to the device under test; wirelessly transmitting 306 control information from the probe adapter to the remote probe; wirelessly transmitting 308 data obtained by the remote probe from the device under test to the probe adapter; and transferring 310 the data from the probe adapter to the tester; wherein the control information directs the setting of electrical characteristics of the remote probe. The probe adapter and the remote probe, in addition to being respectively electrically coupled to the tester and DUT, may also be physically mounted to their respective tester and DUT. Such physical mounting is typically of a removably attachable type, and may be implemented by any suitable attachment means, including but not limited to, clips, snaps, clamps, threaded screws, and so on. In an alternative embodiment of the present invention, a test procedure may be initiated on the tester, where the test procedure includes providing one or more instructions to the probe adapter. Such instructions may be for controlling the probe adapter itself, such as but not limited to setting an address of the probe adapter, or specifying a wireless communication protocol.

In a further alternative embodiment, providing one or more instructions to the probe adapter from the tester causes the probe adapter to transmit control information to the remote probe.

Described herein are methods and apparatus for wireless communication between a tester and a device under test.

Various embodiments of the present invention include a probe adapter and a remote probe which taken together replace a wired connection between a tester and device under test.

Embodiments of the present invention provide for communication of control information between the probe adapter and the remote probe, in addition to data obtained from the device under test being obtained by the remote probe and transmitted to the probe adapter. The probe adapter provides the data obtained from the device under test to the tester to which the probe adapter is coupled.

Embodiments of the present invention may find application in a wide variety of systems or endeavors in which a wired probe is attached to a piece of measurement equipment. This includes, but is not limited to, electronic test equipment such as oscilloscopes, spectrum analyzers and logic analyzers; and medical test equipment such as EKG's, EEG's and ultrasound diagnostic equipment.

It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the subjoined Claims and their equivalents.

Claims

CLAIMSWhat is claimed is:

1. A method of interfacing with a device under test and communicating data therefrom to a remotely located tester, and for transmitting control information from the remotely located tester to the interface with the device under test, comprising: coupling 302 a probe adapter 100 to the tester; coupling 304 a remote probe 200 to the device under test; wirelessly transmitting 306 control information from the probe adapter 100 to the remote probe 200; wirelessly transmitting 308 data obtained by the remote probe 200 from the device under test to the probe adapter 100; and transferring 310 the data from the probe adapter 100 to the tester; wherein the control information directs the setting of electrical characteristics of the remote probe 200.

2. The method of Claim 1, further comprising: initiating a test procedure on the tester, the test procedure including providing one or more instructions to the probe adapter 100.

3. The method of Claim 2, wherein providing one or more instructions to the probe adapter 100 causes the probe adapter 100 to transmit control information to the remote probe 200.

4. The method of Claim 3, wherein coupling the probe adapter 100 to the tester includes removably attaching the probe adapter 100 to the tester.

5. The method of Claim 3, wherein the remote probe 200 is a hand-held unit.

6. The method of Claim 3, wherein coupling 304 the remote probe 200 to the device under test includes removably attaching the remote probe 200 to at least one electrical node of the device under test.

7. The method of Claim 3, wherein coupling 304 the remote probe 200 to the device under test includes removably attaching the remote probe 200 to a probe card of a wafer prober.

8. The method of Claim 3, further comprising applying an input stimulus from the remote probe 200 to the device under test.

9. The method of Claim 8, further comprising supplying the input stimulus from the probe adapter 100 to the remote probe 200.

10. A system for interfacing with a device under test and communicating information therefrom to a remotely located tester, and for transmitting control information from the remotely located tester to the interface with the device under test, comprising: a probe adapter 100 electrically coupled to the tester; a remote probe 200 electrically coupled to the device under test, and adapted for wirelessly coupling with the probe adapter 100; wherein the remote probe 200 is adapted to obtain data from at least one electrical node of the device under test and to wirelessly transmit that data to the probe adapter 100; wherein the remote probe 200 is adapted to receive control information from the probe adapter 100, the control information regarding electrical characteristics of the remote probe 200; wherein the probe adapter 100 is adapted to receive a wireless transmission from the remote probe 200 and to provide the data obtained from the device under test to the tester; and wherein the tester is adapted to provide instructions to the probe adapter 100 regarding communication with the remote probe 200.

11. The system of Claim 10, wherein the probe adapter 100 is removably attached to the tester.

12. The system of Claim 11 , wherein remote probe 200 is further adapted to provide input stimulus to the device under test.