Patent Application
20200116759
Compliant test probe capable of probing non coplanar contacts and related methods.
Radio Frequency (RF) characterization probes provide a precision impedance matched contact geometry to probe small transmission line structures on semiconductor devices, printed circuit boards (PCB), semiconductor wafers, or any other small geometries that need RF characterization.
RF characterization probes are available. However, the probes available on the current market are expensive, fragile, and not all are field-repairable. The current probes are made using small coaxial cable and either machining the contact end of the probe or soldering small flanges on to the contact end to provide a coplanar termination. These are not field repairable nor are they configurable. What is needed is a lower cost, more robust, field-reparable, and more configurable probe.
A test probe assembly includes a mounting fixture, a co-planar waveguide lead frame having a device contact point, where the co-planar waveguide lead frame is mounted to the mounting fixture, and at least one radio frequency (RF) connector electrically coupled with the co-planar waveguide lead frame.
In one or more embodiments, the co-planar waveguide lead frame has a metal layer and a substrate layer.
In one or more embodiments, the metal layer has a signal lead surround on two sides by a ground.
In one or more embodiments, a gap and signal width are defined to match impedance of test equipment.
In one or more embodiments, the gap and the signal width are defined to match impedance of a device under test (DUT).
In one or more embodiments, the co-planar waveguide lead frame is a single ground-signal-ground co-planar waveguide lead frame.
In one or more embodiments, the co-planar waveguide lead frame is a single ground-signal-signal-ground co-planar waveguide lead frame.
In one or more embodiments, the co-planar waveguide lead frame is of any number of combinations of signal and ground probe cluster configurations for any custom individual device under test a single ground-signal-signal-ground co-planar waveguide lead frame.
In one or more embodiments, the co-planar waveguide lead frame can include a single-ended to differential balun.
In one or more embodiments, the co-planar waveguide lead frame is multiple ground-signal-ground configuration(s) of co-planar waveguide lead frame.
In one or more embodiments, the co-planar waveguide lead frame has mounting structure.
In one or more embodiments, the mounting structure includes one or more of screw holes or dowel pin slots.
In one or more embodiments, the mounting structure includes one or more compression screws to hold the connector in place.
In one or more embodiments, the at least one RF connector assembly is defined by a longitudinal axis, the longitudinal axis disposed at about a 45 degree angle relative to a plane defining in part the co-planar waveguide lead frame.
In one or more embodiments, the RF connector assembly has a center conductor assembly compression mounted to the co-planar waveguide lead frame.
In one or more embodiments, the RF connector assembly has a center conductor assembly, the center conductor assembly includes one or more spacers.
In one or more embodiments, the one or more spacers are cross-linked polystyrene microwave plastic spacers.
In one or more embodiments, a test probe assembly includes a mounting fixture, and a co-planar waveguide lead frame with a device contact point. The co-planar waveguide lead frame is mounted to the mounting fixture. At least one radio frequency (RF) connector is electrically coupled with the co-planar waveguide lead frame. The at least one RF connector assembly includes a center conductor assembly which includes a center conductor, and the center conductor extends from a first end to a second end and is defined in part by a conductor longitudinal axis.
In one or more embodiments, the center conductor includes a tapered end at the first end.
In one or more embodiments, the center conductor includes one or more recessed portions.
In one or more embodiments, the test probe assembly further includes one or more spacers disposed within the one or more recessed portions.
In one or more embodiments, the one or more spacers are cross-linked polystyrene microwave plastic spacers.
In one or more embodiments, the one or more spacers have a disc shape.
In one or more embodiments, the at least one RF connector assembly is defined by a longitudinal axis, the longitudinal axis disposed at about a 45 degree angle relative to a plane defining in part the co-planar waveguide lead frame.
In one or more embodiments, a gap and signal width are defined to match impedance of test equipment.
In one or more embodiments, the gap and the signal width are defined to match impedance of a DUT.
These and other embodiments, aspects, advantages, and features of the present invention will be set forth in part in the description which follows, and will become apparent to those skilled in the art by reference to the following description of the invention and referenced drawings or by practice of the invention. The aspects, advantages, and features of the invention are realized and attained by means of the instrumentalities, procedures, and combinations particularly pointed out in the appended claims and their equivalents.
The following detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the apparatus may be practiced. These embodiments, which are also referred to herein as “examples” or “options,” are described in enough detail to enable those skilled in the art to practice the present embodiments. The embodiments may be combined, other embodiments may be utilized or structural or logical changes may be made without departing from the scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense and the scope of the invention is defined by the appended claims and their legal equivalents.
In this document, the terms “a” or “an” are used to include one or more than one, and the term “or” is used to refer to a nonexclusive “or” unless otherwise indicated. In addition, it is to be understood that the phraseology or terminology employed herein, and not otherwise defined, is for the purpose of description only and not of limitation.
An integrated circuit test probe assembly 100 is described herein, and shown in the drawings. The test probe assembly 100 includes a co-planar waveguide construction, combined with a mechanically mounted custom radio frequency (RF) connector to provide matched compliant probing mechanism for probing semiconductor devices, PCBs, substrates, bare die, etc. at frequencies up to 110 GHz or even up to 1 THz. The construction and assembly allows for simple customization and replacement of individual components. The probe assembly is more robust than previous probes, and can be repaired and configured in the field.
The test probe assembly 100 is shown in general in
Referring to
In one or more embodiments, the co-planar waveguide lead frame 120 includes a single ground-signal-ground co-planar waveguide, as shown in
In one or more embodiments, the co-planar waveguide lead frame is a single ground-signal-ground co-planar (GSG) waveguide lead frame, as shown in
The co-planar waveguide lead frame 120 is defined in part by a plane 138, as shown in
The RF connector assembly allows connection from the co-planar waveguide lead frame 120 to the test equipment through, for example, 1 mm, 1.85 mm, 2.92 mm, and SMA standard connector interfaces. The RF connector assembly includes a threaded portion that can be replaceable for any cable standard available. The RF connector assembly 180 provides the shortest path from the cable to the co-planar waveguide lead frame 120 and is fully impedance controlled from the cable connection to the interface of the co-planar waveguide lead frame 120.
The RF connector assembly 180 is defined in part by a longitudinal axis 182 as shown in
The barrel of the RF connector assembly 180 can be formed, for example, from common rod stock. The physical connection from the connector to the co-planar waveguide lead frame 120 is accomplished using cap screws located on the bottom of the RF connector assembly. The screw holes in the body can be tapped to allow mounting of the co-planar waveguide lead frame 120 directly to the RF connector assembly or they can be through holes to allow the connector to sandwich the co-planar waveguide lead frame 120 between the RF connector assembly 180 and another body of material under the co-planar waveguide lead frame 120.
In one or more embodiment, the RF connector assembly 180 includes a center conductor assembly 150. The at least one RF connector assembly 180 includes a center conductor assembly 150 which includes a center conductor 154 and a housing 152. The center conductor 154 extends from a first end 156 to a second end 158 and is defined in part by a conductor longitudinal axis 160. In one or more embodiments, the center conductor 154 includes a tapered end 162 at the second end 158. In one or more embodiments, the center conductor 154 includes one or more recessed portions 156. In one or more embodiments, the test probe assembly further includes one or more spacers 158 disposed within the one or more recessed portions 156. In one or more embodiments, the one or more spacers 158 are cross-linked polystyrene microwave plastic spacers. In one or more embodiments, the one or more spacers 158 have a disc shape. The spacers 158 are disposed between the housing 152 and the center conductor 154 (See
The center conductor 154 of the center conductor assembly 150 maximizes the impedance match at the interface between the center conductor 154 and the co-planar waveguide lead frame 120. The center conductor 154 is tapered and compression mounted, in one embodiment, to the co-planar waveguide lead frame 120 such that it ensures a reliable connection and provides optimal impedance match between connector and lead frame. The taper is angled to maximize the surface area of contact to the co-planar waveguide lead frame 120, as shown in
The test probe assembly includes a co-planar waveguide construction, combined with a mechanically mounted custom radio frequency (RF) connector to provide matched compliant probing mechanism for probing semiconductor devices, PCBs, substrates, bare die, etc. at frequencies up to 110 GHz or even up to 1 THz. The probe tip is independently compliant and can bend to be used on non-planar surfaces. The construction and assembly allows for simple customization and replacement of individual components. The probe assembly is more robust than previous probes, and can be repaired and configured in the field. The lead frame can be customized for any ground/signal pitch required for testing (typical pitches range from 50 to 1250 um). The lead frame is replaceable and can be interchanged for different DUT requirements.
It is to be understood that the above description is intended to be illustrative, and not restrictive. Many other embodiments will be apparent to those of skill in the art upon reading and understanding the above description. It should be noted that embodiments discussed in different portions of the description or referred to in different drawings can be combined to form additional embodiments of the present application. The scope should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.
This application claims priority to U.S. Provisional Application No. 62/744,463 that was filed on Oct. 11, 2018. The entire content of the application referenced above is hereby incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| 62744463 | Oct 2018 | US |
