WO2019168587A1

WO2019168587A1 - Test socket assembly with hybrid ring coupler and related methods

Info

Publication number: WO2019168587A1
Application number: PCT/US2018/067235
Authority: WO
Inventors: Jason Mroczkowski; Nadia STECKLER; Mike HANKS; Pat GARMAN
Original assignee: Xcerra Corporation
Priority date: 2018-02-27
Filing date: 2018-12-21
Publication date: 2019-09-06

Abstract

A test socket assembly includes a frame assembly having one or more compliant interconnects, and a socket opening sized and configured to receive a device under test therein. The test socket assembly further includes a lead frame assembly disposed adjacent to the frame assembly and electrically coupled with the one or more compliant interconnects. The lead frame assembly includes a hybrid ring coupler.

Description

TEST SOCKET ASSEMBLY WITH HYBRID RING COUPLER AND RELATED

METHODS

PRIORITY APPLICATION

This application claims priority to United States Provisional Application Number 62/635,989 that was filed on February 27, 2018. The entire content of the application referenced above is hereby incorporated by reference herein.

TECHNICAL FIELD

Test contactor assemblies and related methods.

TECHNICAL BACKGROUND

Test contactors are used on printed circuit boards to test various parameters and/or components of semiconductor devices. Electronic devices have become smaller yet more powerful, resulting crowded and complex circuit boards. For example, modem automobiles are using RADAR equipment for collision avoidance, parking assist, automated driving, cruise control, etc. The radio frequencies used in such systems are typically 76 - 81 GHz (W-band). Also, the radio frequencies used for wifi applications are in the range of 56 - 64 GHz. Next generation IC's will push operating frequencies to even higher levels, for example in the cellular backhaul market space. Furthermore, semiconductor devices include antenna in package to minimize the footprint of the overall wireless chipset. Semiconductor devices that operate at these frequencies need to be tested, but existing test contactor technology cannot split or combine signals bi-directionally inside the contactor to increase the number of device under test RF communication channels. Furthemore, the use of a ring coupler maximizes the isolation between ports and maximizes the useful frequency range of the contactor. This is an advantage over existing technologies as it reduces the number of expensive tester resources necessary to test mmWave frequency input and output ports on the device under test.

SUMMARY

The test socket assembly described herein is a test socket assembly including a hybrid ring coupler therein.

A test socket assembly includes a frame assembly having a socket opening sized and configured to receive a device under test therein, a lead frame assembly disposed within the frame assembly, the lead frame assembly includes at least one hybrid ring coupler. The at least one hybrid ring coupler includes at least one ring, at least one isolation port, at least one input, and at least two outputs. At least one of the at least two outputs include a device contact portion, where the device contact portion is configured to communicate to the device under test when the device under test is disposed within the socket opening.

In one or more embodiments a test socket assembly includes a frame assembly having a socket opening sized and configured to receive a device under test therein, a lead frame assembly disposed adjacent to the frame assembly. The lead frame assembly further includes at least one hybrid ring coupler, the at least one hybrid ring coupler including at least one ring, at least one isolation port, at least one input, and at least two outputs, where the at least one isolation port is a terminator. The lead frame assembly further includes a microstrip disposed between co-planar waveguides, the microstrip having the frame assembly as a ground plane, and the microstrip having the at least one hybrid ring coupler therein. At least one of the at least two outputs include a device contact portion, and the device contact portion is configured to communicate to the device under test when the device under test is disposed within the socket opening.

In one or more embodiments, the frame assembly is a ground reference for the at least one hybrid ring coupler.

In one or more embodiments, the at least one hybrid ring coupler is a splitter.

In one or more embodiments, the at least one hybrid ring coupler is a combiner.

In one or more embodiments, the at least one hybrid ring coupler provides a phase shift between the at least one input and the at least two outputs

In one or more embodiments, the at least one hybrid ring coupler is a microstrip hybrid ring coupler.

In one or more embodiments, the test socket assembly further includes an absorber on the isolation port.

In one or more embodiments, the test socket assembly further includes a support member adjacent the absorber, the support member providing support to the absorber.

In one or more embodiments, the test socket assembly includes a transition from coplanar waveguide to microstrip and/or a transition from microstrip to coplanar waveguide

In one or more embodiments, the test socket assembly further includes a loop back trace electrically coupled between the at least one input and the at least two outputs.

In one or more embodiments, the test socket assembly further includes at least two hybrid ring couplers, and the at least two hybrid ring couplers are cascaded. In one or more embodiments, the test socket assembly further includes the frame assembly having a pocket that provides an air gap adjacent the ring of the at least one hybrid ring coupler.

A method for testing components comprises disposing a device under test in a test socket assembly, the test socket assembly including a frame assembly having a socket opening sized and configured to receive a device under test therein, a lead frame assembly disposed within the frame assembly, the lead frame assembly including at least one hybrid ring coupler including at least one ring, at least one isolation port, at least one input, and at least two outputs, at least one of the at least two outputs include a device contact portion. The method further includes contacting the device under test with the device contact portion, and sending signals to the device under test with the at least one hybrid ring coupler, and the device under test receives the signals.

In one or more embodiments, the method further includes supporting the absorber with a support member.

In one or more embodiments, the method further includes terminating the signal at the absorber.

In one or more embodiments, the method further includes splitting the signal.

In one or more embodiments, the method further includes combining the signal.

In one or more embodiments, the method further includes sending low speed signals between the device under test and the printed circuit board via the one or more compliant interconnects.

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.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 illustrates a perspective view of a portion of a test socket assembly as constructed in one or more embodiments.

FIG. 2 illustrates an exploded perspective view of a test socket assembly as constructed in one or more embodiments.

FIG. 3 illustrates a portion of a lead frame assembly of a test socket assembly as constructed in one or more embodiments. FIG. 4 illustrates a schematic of a hybrid ring coupler as constructed in one or more embodiments.

FIG. 5 illustrates a top view of a hybrid ring coupler of a test socket assembly as constructed in one or more embodiments.

FIG. 6A illustrates a schematic of a hybrid ring coupler in a coplanar waveguide as constructed in one or more embodiments.

FIG. 6B illustrates a schematic of a series of hybrid ring couplers as constructed in one or more embodiments.

FIG. 7 illustrates a perspective view of a portion of the lead frame assembly with microstrip hybrid ring couplers as constructed in one or more embodiments.

FIG. 8 illustrates a perspective view of a portion of the lead frame assembly with hybrid ring couplers as constructed in one or more embodiments.

FIG. 9 illustrates a bottom perspective view of a hybrid ring coupler as constructed in one or more embodiments.

FIG. 10 illustrates a top perspective view of a hybrid ring coupler as constructed in one or more embodiments.

FIG. 11 illustrates a cross-sectional view of a transition between the coplanar waveguide and the microstrip as constructed in one or more embodiments.

FIG. 12 illustrates a top view of a portion of a lead frame assembly as constructed in one or more embodiments.

FIG. 13 illustrates a detailed perspective of a portion of the lead frame assembly as constructed in one or more embodiments.

DETAILED DESCRIPTION

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.

FIGs. 1, 3 - 5 illustrate a test socket assembly 100, such as an mmWave contactor, with one or more hybrid ring coupler 150 incorporated into a lead frame assembly 140 of the test socket assembly 100. In one or more embodiments, the test socket assembly 100 is used with a device under test (DUT) 200, and can communicate via compliant interconnects with the device under test 200. The test socket assembly 100 allows direct communication between test hardware and the device under test while maintaining a contacted spring probe interface for remaining standard inputs and outputs on a BGA/QFN/WLCSP, or any other packaging technology. The test socket assembly 100 can include compliant interconnects and compliant or static lead frames and other features as described in US2015/0369840, which is incorporated herein by reference in its entirety.

In one or more embodiments the test socket assembly 100 includes frame assembly 130, a lead frame assembly 140, a contactor body 131, compliant interconnects 120, a printed circuit board 132, probe retainer plate 122, and one or more dowel pins 136, as shown in FIG. 2, which shows an exploded view of the test socket assembly 100. There is also substrate material which is used to align and hold the lead frame assembly 140 together.

The test socket assembly 100 is used with a device under test (DUT) 200. A socket opening 192 within the frame assembly 130 receives the DUT 200 therein and assists in aligning the DUT 200 with the test socket assembly 100. The socket opening 192 is sized and configured to receive the DUT 200 therein.

The test socket assembly 100 includes a lead frame assembly 140 and one or more compliant interconnects 120, and at least one return 124. The spring return 124 provides force back up into the assembly 100 and supports the lead frame assembly 140. The lead frame assembly 140 is disposed adjacent to the frame assembly 130, and is electrically coupled with the one or more compliant interconnects 120, which are also disposed within the frame assembly 130. The lead frame assembly 140 is sandwiched between the frame assembly 130 and the contactor body 131.

FIGs. 3, 7, and 12 illustrate a portion the lead frame assembly 140 in greater detail. The lead frame assembly 140 includes a hybrid ring coupler 150 (FIGs. 4, 5) including at least one ring 158, at least one input 152, at least two outputs 154, where the hybrid ring coupler 150 forms part of the lead frame assembly 140. At least one of the at least two outputs include a device contact portion 156 to contact the DUT 200 when the DUT is disposed within the socket opening 134. The hybrid ring coupler 150 further includes a terminator, such as isolation port

160 with an absorber 162. In one or more embodiments, the leadframe assembly 140 includes a loop back trace 146 electrically coupled between the at least one input 152 and the at least two outputs 154.

The hybrid ring coupler 150 provides a relatively large band width. The input signal goes in at the at least one input 152 (port 1, 151), and the output signal is at outputs 154 (ports 2 and 3, 153, 155). Between the at least one input 152 and the outputs 154 there is a phase shift. When the signal enters the at least one input 152 and out of the outputs 154, the loss is the same for a certain frequency range, and this frequency range is the bandwidth. The return loss is low, and the reflections are minimized by the terminator. Any signals that bounce off the intersection get absorbed by the terminator. The absorber can bring the return loss to -l5dB. The hybrid ring coupler 150 is disposed in a pocket 133 of the frame assembly 130 (FIG. 3). The pocket 133 provides an air gap 138 adjacent to the ring 158 of the hybrid ring coupler 150. The air gap provides a low dielectric for high frequency signals. This geometry assists in achieving a high bandwidth and high isolation signal between ports 2 and 3 (153, 155). The pocket 133 is surrounded by a metal frame that creates a ground for the microstrip ring coupler.

The hybrid ring coupler 150 can be used as a splitter or a combiner; it is bi-directional. For a splitter, the input 152 and outputs 154 are used as discussed above. The signal goes in one port, such as port 1 (151), and the signal is split and phase shifted, and goes out ports 2 and 3 (153, 155). For a combiner, the input and outputs are switched. The signal is inputted into the outputs 154 (ports 2, 3 (153, 155)), the signal is combined and the combined signal is output via port 1 (151).

FIG. 6 A illustrates the use of a coplanar waveguide 170 as a hybrid ring coupler 150. In this case, a bridge 171 is used because the grounds are isolated. The ground plane and the signal are on the same layer.

In one or more embodiments, multiple hybrid ring couplers 150 can be used, as shown in FIG. 6B. The hybrid ring couplers 150 are cascaded when more than two ports are to be terminated. For example, the signal can come out on two ports on one hybrid ring coupler, and out of another two ports on a second cascaded hybrid ring coupler to achieve four ports.

Additional hybrid ring couplers 150 can be used in the cascaded arrangement.

FIGs. 3, 7 - 12 illustrate the frame assembly 130 and lead frame assembly 140 in greater detail. The hybrid ring coupler 150 is formed by the lead frame assembly 140. In one or more embodiments, the hybrid ring coupler 150 is in a microstrip 172, as shown in FIG. 7. Co-planar waveguides 170 are disposed on either side of the microstrip 172. The signal line 180 goes through the co-planar wave guide 170, to the microstrip 172, and back to the co-planar waveguide 170. The lead frame assembly 140 further includes a lead frame ground 148. The hybrid ring coupler 150 includes at least one input 152, at least two outputs 154, an isolation port 160 with an absorber 162. The absorber 162 is a rubber component that is an Rf absorber, and it absorbs any signal that comes down the line. The absorber 162 is relatively thicker than the microstrip and extends into the frame assembly 130. The frame assembly 130 has a pocket 163 to receive the absorber 162 and support member 164 therein. The pockets are used because the absorber is thicker than the ring coupler, as shown in FIG. 10. The absorber 162 contacts both the lead frame assembly and the ground surface. The absorbers 162 contact to the ground to complete the circuit. The absorber 162 contacts the frame assembly to provide termination for the isolation port 160. The terminator (isolation port 160) uses the frame assembly 130 as a ground reference.

A support member 164 is provided as shown in FIG. 8. The support member 164 provides support to the absorber 162. A pocket 163 is provided for the support member 164. In one or more embodiments, the support member 164 is formed by the contactor body 131. The contactor body 131 and the support member 164 are used to sandwich and compress the isolation port 160 between the absorber 162 and the contactor body 131 to ensure contact between the isolation port 160 and the absorber 162. The support member 164 is not over all of the leadframe assembly 140 since air near the leadframe assembly is used as the dielectric to maximize frequency response and minimize the low. In addition, the compression assists in contacting the frame assembly 130 with the leadframe assembly 140.

Referring to FIGs. 10 - 13, which shows the frame assembly 130 in greater detail, the frame assembly 130 connects directly to the lead frame assembly 140. The frame assembly 130 is used as a ground reference to balance the co-planar waveguide ground potential. The frame assembly 130 is used to make connections between the grounds. The frame assembly 130 connects directly to the leadframe assembly 140, and connects the two grounds to ensure the same ground potential. In one or more embodiments, the frame assembly 130 has one or more bosses 137 projecting out from the frame assembly 130 which are used to contact the lead frame assembly 140. In one or more embodiments, the lead frame assembly 140 includes a microstrip 172 disposed between co-planar waveguides 172, where the microstrip 172 includes at least one hybrid ring coupler 150 therein and has the frame assembly 130 as a ground plane. In one or more embodiments, the one or more bosses 137 are at a transition 174 between the coplanar waveguide 170 and the microstrip 172 (FIGs. 10, 11). There also is a transition from the microstrip to the coplanar waveguide, in one or more embodiments. The one or more bosses 137 of the frame assembly 130 contact the lead frame assembly 140, and allow for an electrical connection between the lead frame assembly 140 and the frame assembly 130. There are cutouts 144 in the substrate material 142 that the metal bosses can directly contact the lead frame assembly 140.

The following is a method for using the test socket assembly. A method for testing components comprises disposing a device under test in a test socket assembly, the test socket assembly including a frame assembly having a socket opening sized and configured to receive a device under test therein, a lead frame assembly disposed within the frame assembly, the lead frame assembly including at least one hybrid ring coupler including at least one ring, at least one isolation port, at least one input, and at least two outputs, where at least one of the at least two outputs include a device contact portion. The method further includes contacting the device under test with the device contact portion, and sending signals to the device under test with the at least one hybrid ring coupler, and the device under test receives the signals.

In one or more embodiments, the method further includes supporting the absorber with a support member. In one or more embodiments, the method further includes terminating the signal at the absorber. In one or more embodiments, the method further includes splitting the signal.

In one or more embodiments, the method further includes combining the signal. In one or more embodiments, the method further includes sending low speed signals between the device under test and the printed circuit board via the one or more compliant interconnects.

In one or more embodiments, the test socket assembly 100 uses vertical compliance to achieve reliability. The compliant interconnects 120 are compliant for the power, ground and low speed signal connections, such as balls. The microwave structures of the lead frame assembly 140 terminate in precision coaxial connectors or waveguides.

In one or more embodiments, the lead frame assembly 140 has holes matched for the pin out array of the compliant interconnects. In one or more embodiments, the lead frame assembly has a first set of holes that are tightly positioned where ground signals need to be in contact with the device under test and spring probe. For example, the lead frame assembly 140 makes electrical contact with the compliant interconnects at the first set of holes. In one or more embodiments, the lead frame assembly 140 further includes a second set of holes which are oversized relative to the spring probe where non-critical signals interface with the device under test 200 (FIG. 2) , such as power lines or other signal lines. For example, the compliant interconnects do not make electrical contact with the lead frame assembly 140 at the second set of holes.

In one or more embodiments, the lead frame microwave structures are terminated externally to precision microwave coaxial connectors 190. In one or more embodiments, the lead frame assembly is impedance matched at the transition to the coaxial connectors 190 for optimal RF performance. The lead frame assembly can include a flat configuration with axially terminating connectors 190.

Several options for the signal lines are as follows. For instance, in one or more embodiments, the lead frame signal lines are configured in a coplanar waveguide transmission line structure. In one or more embodiments, the lead frame signal lines can be split with a balun structure, so that the split signals shift phase to a prescribed amount at a prescribed frequency.

In one or more embodiments, the lead frame signal lines can incorporate loopback structures that connect an input and output signal of a device under test for testing.

The coplanar waveguide transmission line structures terminate to a coaxial feed through connector or surface mounted connector, in one or more embodiments. A reduced diameter of the center conductor of the connector mates with an end of the lead frame assembly 140 lead.

An electrical connection can be made, for example, by soldering the connection. In one or more embodiments, the ground plane can be mechanically attached, such as clamped with metal fasteners. This connection can be used to connect all of the ground planes to the socket body.

In one or more embodiments, a transition from the lead frame signal line to the coaxial connector is matched so that impedance discontinuities are minimized for high speed performance.

In one or more embodiments, the lead frame microwave structures are terminated externally to precision microwave coaxial connectors. In one or more embodiments, the lead frame is impedance matched at the transition to the coaxial connectors 190 for optimal RF performance. The coaxial connectors 190 can be surface mounted to the lead frame assembly.

The test socket assembly described and shown herein is a test socket that is compatible with semiconductor back-end manufacturing, yet is capable in operating at the W-band frequencies and includes a hybrid ring coupler embedded within the contactor as a splitter, and including an isolation port terminator. The hybrid ring coupler allows for the large bandwidth and high isolation when splitting a signal from one line to two lines, and can be used for splitting high frequency signals. The test socket assembly includes a frame assembly that is used as a ground reference for the hybrid ring coupler and terminator. The frame assembly of the test socket assembly is further used to balance the coplanar waveguide ground potential.

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.

Claims

1. A test socket assembly comprising:

a frame assembly having a socket opening sized and configured to receive a device under test therein;

a lead frame assembly disposed adjacent to the frame assembly, the lead frame assembly including at least one hybrid ring coupler including at least one ring, at least one isolation port, at least one input, and at least two outputs, where the at least one isolation port is a terminator; at least one of the at least two outputs include a device contact portion; and

the device contact portion configured to communicate to the device under test when the device under test is disposed within the socket opening.

2. The test socket assembly as recited in claim 1, wherein the frame assembly is a ground reference for the at least one hybrid ring coupler.

3. The test socket assembly as recited in claim 1, wherein the at least one hybrid ring coupler is a splitter.

4. The test socket assembly as recited in claim 1, wherein the at least one hybrid ring coupler is a combiner.

5. The test socket assembly as recited in claim 1, wherein the at least one hybrid ring coupler provides a phase shift between the at least one input and the at least two outputs.

6. The test socket assembly as recited in any one of claims 1 - 5, wherein the at least one hybrid ring coupler is a microstrip hybrid ring coupler.

7. The test socket assembly as recited in any one of claims 1 - 6, further comprising an absorber on the isolation port.

8. The test socket assembly as recited in claim 7, further comprising a support member adjacent the absorber, the support member providing support to the absorber.

9. The test socket assembly as recited in any one of claims 1 - 8, further comprising a loop back trace electrically coupled between the at least one input and the at least two outputs.

10. The test socket assembly as recited in any one of claims 1 - 9, further comprising at least two hybrid ring couplers, and the at least two hybrid ring couplers are cascaded.

11. The test socket assembly as recited in any one of claims 1 - 10, wherein the frame assembly has a pocket that provides an air gap adjacent the ring of the at least one hybrid ring coupler.

12. A method for testing components comprising:

disposing a device under test in a test socket assembly, the test socket assembly including a frame assembly having a socket opening sized and configured to receive a device under test therein, a lead frame assembly disposed within the frame assembly, the lead frame assembly including at least one hybrid ring coupler including at least one ring, at least one isolation port, at least one input, and at least two outputs, at least one of the at least two outputs include a device contact portion;

contacting the device under test with the device contact portion;

and

sending signals to the device under test with the at least one hybrid ring coupler, and the device under test receives the signals.

13. The method as recited in claim 12, further comprising an absorber on the isolation port, and supporting the absorber with a support member.

14. The method as recited in claim 13, further comprising terminating the signal at the absorber.

15. The method as recited in any one of claims 12 - 14, further comprising splitting the signals.

16. The method as recited in any one of claims 12 - 15, further comprising combining the signals.

17. The method as recited in any one of claims 12 - 16, further comprising a co-planar waveguide, and using the frame assembly to balance a ground potential of the co-planar waveguide.

18. A test socket assembly comprising:

a lead frame assembly disposed adjacent to the frame assembly;

the lead frame assembly including at least one hybrid ring coupler, the at least one hybrid ring coupler including at least one ring, at least one isolation port, at least one input, and at least two outputs, where there are more outputs than inputs and the at least one isolation port is a terminator;

the lead frame assembly including a microstrip disposed between co-planar waveguides, the microstrip having the frame assembly as a ground plane, the microstrip having the at least one hybrid ring coupler therein;

at least one of the at least two outputs include a device contact portion; and

19. The test socket assembly as recited in claim 18, further comprising a transition between the microstrip and the co-planar waveguides.

20. The test socket assembly as recited in claim 18, wherein the at least one hybrid ring coupler is a splitter.

21. The test socket assembly as recited in claim 18, wherein the at least one hybrid ring coupler is a combiner.

22. The test socket assembly as recited in any of claims 18 - 21, wherein the at least one hybrid ring coupler provides a phase shift between the at least one input and the at least two outputs.

23. The test socket assembly as recited in any of claims 18 - 22, further comprising an absorber on the isolation port.

24. The test socket assembly as recited in claim 23, further comprising a support member adjacent the absorber, the support member providing support to the absorber.

25. The test socket assembly as recited in any of claims 18 - 24, further comprising at least two hybrid ring couplers, and the at least two hybrid ring couplers are cascaded.

26. The test socket assembly as recited in any of claims 18 - 25, wherein the frame assembly has a pocket that provides an air gap adjacent the ring of the at least one hybrid ring coupler.