WO2019168561A1

WO2019168561A1 - Test socket assembly and related methods

Info

Publication number: WO2019168561A1
Application number: PCT/US2018/050028
Authority: WO
Inventors: Valts Treibergs; Dan Sikorski
Original assignee: Xcerra Corp
Current assignee: Xcerra Corp
Priority date: 2018-03-02
Filing date: 2018-09-07
Publication date: 2019-09-06
Anticipated expiration: 2020-09-02

Abstract

A test socket assembly for coupling a device under test to a test apparatus includes a housing, and a pivotable link, elastomer, and slidable mount at least partially disposed within a cavity of the housing. The pivotable link and slidable mount are disposed adjacent to the elastomer such that the elastomer biases both the first contact end of the link and the PCB contact members of the slidable mount toward out of the housing. The slidable mount has a side wall defined by a side wall plane, where the side wall plane is vertically slidable along an inner side wall of the housing.

Description

TEST SOCKET ASSEMBLY AND RELATED METHODS

RELATED APPLICATION

This application claims priority to United States Provisional Application Number 62/637,610 that was filed on March 2, 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

Microchips have become prevalent in virtually all types of industries, and the demand for microchips has dramatically increased over the last several years. A microchip connects to a motherboard or other device via a plurality of pins or terminals, which allows the board to communicate with the chip's logic or memory. An example of such a chip may be a memory card or processor for a computer, each of which may be insertable into a particular slot or socket that makes one or more electrical connections with the chip.

Part of the manufacturing process of the chips is the post-production testing of the quality and performance of the chip. Testing helps to diagnose problems in the manufacturing process, and improve production yields for systems that incorporate the chips. Sophisticated test systems have been developed to ensure that the circuitry in the chip performs as designed. A randomly selected chip is obtained from a production batch and attached to a tester or test socket. The selected test chip is referred to as a device under test, or "DUT." The test socket is connected to a test apparatus that sends signals to the chip and evaluates the responsiveness and effectiveness of the chip as manufactured. In general, it is desirable to perform the attachment, testing, and detachment as rapidly as possible, so that the throughput of the tester may be as high as possible.

The test apparatus accesses the microchip's circuitry through the same pins or terminals that will later be used to connect the chip in its final application. Accordingly, it is preferable that the test apparatus establish a reliable electrical contact with the chip's various pins or terminals so that the pins are not damaged, while maintaining a sound electrical connection with the pins.

Most test apparatus of this type use mechanical contacts between the chip pins and the contacts on the test apparatus, rather than a more permanent attachment of the chip to the tester.

When the chip is inserted in the test socket and coupled electrically to the test apparatus, each pin on the chip is engaged mechanically and electrically with a corresponding electrical connector on the test apparatus.

Preferably, the testing procedure involves as little mechanical wear on the chip and the test apparatus as possible during the attachment, testing, and detachment procedures. Typically, the test apparatus is designed to leave the chips in a final state that resembles the initial state as closely as possible. In addition, it is also desirable to avoid or reduce any permanent damage to the tester or tester pads, so that tester parts may last longer before replacement. In addition, test probes must account for manufacturing tolerance variability in the form of compliance, which is the mechanical flexibility to consistently test devices of differing sizes.

U.S. Patent No. 7,918,669 to Tiengtum entitled "Integrated circuit socket with a two- piece connector with a rocker arm", the contents of which are fully incorporated herein by reference, relate to a test socket that can be used to couple the DUT with a test apparatus. The '669 Patent includes a two piece connector that pivots when a test chip is placed on the socket so as to make contact between a contact pad on the chip and the another electrical contact on the test apparatus, enabling an evaluation of signal transmission by the chip. The platform houses a resilient tubular elastomer that biases the connector assembly in a disengaged position out of contact with the test apparatus. When the chip is placed on the socket, the linkage pivots and the bias of the resilient tubular member is overcome by the downward force applied by the chip, and an electrical connection is established across the connector assembly.

While the system of the '669 Patent has been proven effective in the testing of integrated chips, the wear on the test apparatus from the linkage leads to costly and time consuming maintenance on the test equipment. The mount in the linkage is rigidly fixed in the test socket, and applies a non-compliant pre-loading on the test apparatus that does not guarantee a reliable and stable connection to the printed circuit board when debris is present or there are excessive tolerances in the component features.

Due to variances between the test equipment and the socket, it is possible that a gap can occur between the test equipment and the socket's electrical connector (mount). This gap can result in failed tests or improper measurements that can prolong the testing procedure and falsely suggest problems with the DUT. What is needed is a test socket assembly that ensures a mechanically compliant and more reliable connection between the mount and the test equipment that does not result in excessive forces applied to the test equipment, and avoids scrubbing of the test equipment.

SUMMARY A test socket assembly for coupling a device under test to a test apparatus is described and shown herein. The test socket assembly includes a housing having at least one cavity therein, the at least one cavity having an inner side wall, and an elastomer disposed within the at least one cavity. A pivotable link is at least partially disposed within the at least one cavity, where the pivotable link extends from a first contact end to a second end and having an intermediate portion therebetween, and the second end has a link pivotable structure. The pivotable link disposed adjacent to the elastomer such that the elastomer biases the first contact end of the link toward out of the housing. A slidable mount is disposed within the at least one cavity of the housing, where the mount includes a mount pivot structure coupled with the link pivotable structure to form a joint hinge that allows rotation of the pivotable link toward and away from the elastomer. The slidable mount has one or more PCB contact members downwardly projecting from the slidable mount. The slidable mount disposed adjacent to the elastomer such that the elastomer biases the PCB contact members toward out of the housing. The mount has a side wall defined by a side wall plane, where the side wall plane is vertically slidable along the inner side wall of the housing.

In one or more embodiments, the pivotable link provides a force to the device under test more than 80% independent from force provided by the slidable mount.

In one or more embodiments, the link pivotable structure is an at least partially cylindrical component, and the mount pivot structure is a cylindrical recess that receives the at least partially cylindrical component therein.

In one or more embodiments, the PCB contact members are offset from the first contact end of the pivotable link such that the PCB contact members are not vertically aligned with the first contact end of the pivotable link.

In one or more embodiments, the slidable mount provides non-scrub force on a PCB side of the test socket assembly.

In one or more embodiments, the intermediate portion of the link is curved and an outer surface of the elastomer is rounded, and the intermediate portion of the link receives the elastomer therein.

In one or more embodiments, a height of the at least one cavity above the mount creates a gap between a socket upper wall and an upper surface of the mount, the gap having a vertical spacing that exceeds a distance that the PCB contact members downwardly project below the lower surface of the socket in the absence of an applied upward force to the protrusions In one or more embodiments, a compliant force is placed on the pivotable link and the slidable mount in a same time period.

In one or more embodiments, the elastomer is a single elastomer that provides force to both the slidable mount and the pivotable link.

A test socket assembly for coupling a device under test to a test apparatus. The test socket includes a housing having at least one cavity therein, the at least one cavity having an inner side wall, an elastomer disposed within the at least one cavity, and a pivotable link at least partially disposed within the at least one cavity, the pivotable link extending from a first contact end to a second end and having an intermediate portion therebetween, where the second end has a link pivotable structure. The pivotable link is configured to rotate within a slidable mount, the pivotable link is disposed adjacent to the elastomer such that the elastomer rotationally biases the first contact end of the link to a position above an outer surface of the test socket assembly in the absence of a force applied on the first contact end. A slidable mount is disposed within the at least one cavity of the housing, the mount including a mount pivot structure coupled with the link pivotable structure to form a joint hinge that allows rotation of the pivotable link toward and away from the elastomer in a single plane of the pivotable link. The slidable mount has one or more PCB contact members downwardly projecting from the slidable mount below a second outer surface of the housing in absence of a force applied to the PCB contact members toward the housing. The mount having a side wall defined by a side wall plane, where the side wall plane is vertically slidable along the inner side wall of the housing.

In one or more embodiments, the intermediate portion of the link is curved and an outer surface of the elastomer is rounded, and the intermediate portion of the link receives the elastomer therein. In one or more embodiments, a height of the at least one cavity above the mount creates a gap between a socket upper wall and an upper surface of the mount, the gap having a vertical spacing that exceeds a distance that

the PCB contact members downwardly project below the lower surface of the socket in the absence of an applied upward force to the protrusions

In one or more embodiments, a compliant force is placed on the pivotable link and the slidable mount in a same time period. For example, after the test socket assembly is mounted to the PCB, and while a DUT is placed in the test socket assembly and being tested.

In one or more embodiments, a method of coupling a device under test to a test apparatus with a test socket assembly is disclosed herein. The method includes disposing a device under test in the test socket assembly, the test socket assembly having a housing with at least one cavity therein, the at least one cavity having an inner side wall, an elastomer disposed within the at least one cavity, a pivotable link at least partially disposed within the at least one cavity, the pivotable link extending from a first contact end to a second end and having an intermediate portion therebetween, the second end having a link pivotable structure, the pivotable link disposed adjacent to the elastomer such that the elastomer biases the first contact end of the pivotable link towards out of the housing, a slidable mount disposed within the at least one cavity of the housing, the mount including a mount pivot structure coupled with the link pivotable structure to form a joint hinge that allows rotation of the pivotable link toward and away from the elastomer, the slidable mount having one or more PCB contact members downwardly projecting from the slidable mount, and the slidable mount disposed adjacent to the elastomer such that the elastomer biases the PCB contact members below a lower surface of the housing, the slidable mount having a side wall defined by a side wall plane, where the side wall plane is vertically slidable along the inner side wall of the housing. The method further includes placing an upward force on the slidable mount at the protrusions and causing the slidable mount to slide upward along the side wall of the at least one cavity.

In one or more embodiments, the method further includes placing a downward force on the pivotable link and causing the pivotable link to pivot about the link pivotable structure.

In one or more embodiments, the method further includes providing a compliant force on the pivoting link and the sliding mount in a same time period. For example, after the test socket assembly is mounted to the PCB, and while a DUT is placed in the test socket assembly and being tested. 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 A illustrates a perspective view of a test socket assembly as constructed in one or more embodiments.

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

FIG. 1C illustrates a side cross-sectional view of a portion of a test socket assembly with a PCT and DUT just prior to the test socket assembly mounted to the PCB as constructed in one or more embodiments.

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

FIG. 3 illustrates a second perspective view of a test socket assembly as constructed in one or more embodiments.

FIG. 4 illustrates a top view of a pivotable link as constructed in one or more embodiments.

FIG. 5 illustrates a top view of a slidable mount as constructed in one or more embodiments.

FIG. 6 illustrates a side view of a test socket assembly in a free-state as constructed in one or more embodiments.

FIG. 7 illustrates a side view of a test socket assembly mounted to a PCB (pre-load state) as constructed in one or more embodiments.

FIG. 8 illustrates a side view of a test socket assembly mounted to a PCB and the link compressed downward by a DUT as constructed in one or more embodiments.

FIG. 9 illustrates a schematic diagram of a test socket assembly mounted to a PCB and fully compressed by a DUT as constructed in one or more embodiments.

FIG. 10 illustrates a side cross-sectional view of a test socket assembly in a free state as constructed in one or more embodiments.

FIG. 11 illustrates a side cross-sectional view of a test socket assembly in a preload state as constructed in one or more embodiments. FIG. 12 illustrates a side cross-sectional view of a test socket assembly in during a test 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.

An integrated circuit test socket assembly 100 is described herein, and shown in the drawings. The test socket assembly is of the type generally described in United States Patent No. 7,918,669, the entire contents of which are incorporated herein by reference. The test socket assembly 100 has one or more alignment features to mount the test socket assembly on the testing equipment. On or within the test socket assembly is a recess which receives the device under test therein. A plurality of electrical connections are formed within the recess. The test socket assembly 100 may be placed, for example, on to a PCB in anticipation of testing the integrated chip. Once the socket is mounted in the on the PCB, the chip is inserted into the test socket assembly by a handler or by hand for testing by placing it in the recess. Other arrangements, both automated and manual, are also possible.

Referring to FIGs. 1A - 1C, the test socket assembly 100 includes contact links such as a pivotable link and a slidable mount 160. The pivotable link 140 is used for interacting with a DUT at a DUT side 102 of a housing 120. The test socket assembly 100 further includes a slidable mount 160 for interacting with test equipment 210 at a PCB side 102 of the housing 100

When the device under test 200 is inserted into the test socket assembly 100, connection pads 202 of the device under test 200 will contact a contact portion of the text socket assembly

100 at a DUT side 104, which will connect with the test equipment 210 at a PCB side 102 of the test socket assembly 100. The connection pads 202 form electrical connections that receive and/or transmit signals, and the test equipment 210 includes a printed circuit board (PCB) 212 with connection pads 214 that are designed to communicate and evaluate the signal transmission from the device under test 200. The quality and integrity of the signal transmitted by the chip can be evaluated by the test equipment 210, as well as a signal received by chip from the test equipment. In this manner, the response of the chip to contact and temperature can be tested prior to shipment of the chip. To avoid soldering the device under test 200 to the test equipment 210, the test socket assembly 100 includes a housing 120 with a plurality of electrical linkages that, when the device under test 200 is placed on the housing 120, which includes components that provide an electrical path from the device under test 200 to the test equipment 210 so that the chip can be reliably tested without damaging the chip. The housing 120 is provided with at least one cavity 122. In one or more embodiments, the housing has a plurality of cavities 122 that are aligned along an edge of the test socket assembly 100 and each cavity 122 has associated with it a first opening in the upper surface that allows a contact link to protrude through.

In each cavity 122 is an elastomer 130 that is used to provide a biasing force to each contact link. In one or more embodiments, a single elastomer 130 is used to provide a direct biasing force to both the pivotable link 140 and the slidable mount 160, where the elastomer 130 is in direct contact with both the pivotable link 140 and the slidable mount 160. In one or more embodiments, the elastomer 130 is a resilient tubular member made of an elastomer that can provide a biasing force on the contact links to maintain the links in a desired orientation or position while maintaining a preload force against the test equipment. The elastomer 130 is positioned in the cavity 122 adjacent the contact links and is optionally accessible through the side of the housing 120. In one or more embodiments, the elastomer 130 is cylindrical but other shapes are used to bias the contact links.

Each cavity 122 includes a designated contact link positioned to make contact with an associated pin, pad, or other connection pad 202 on the device under test 200 to be tested. Each contact link is biased by the elastomer 130 so as to extend from its associated cavity 122 through its associated first opening 136 and the first contact end 142 is past the housing surface 132 when no opposing force is placed on it. The contact links are biased by its respective tubular member in a first extended position toward the connection pad 202, and each pivotable link 140 is arranged for pivotal movement about an axis parallel to the axis of the elastomer 130.

The pivotable link 140, as shown in FIG. 4 include a curved portion that allows for scrubbing of the electrical connectors to occur. The pivotable link 140 can be formed from an electrically conductive material with high hardness and strength. In one or more embodiments, the pivotable link 140 can be coated on exterior surfaces to enhance electrical reliability and prevent corrosion. In one or more embodiments, the pivotable link 140 and the slidable mount can be made using one or more of the following techniques: stamping, chemically etching, water jet cutting, wire EDM machining, 3D printing, wafer lithography, or electroforming. In one or more embodiments, the components are manufactured from an electrically conductive material, such as metal, with high hardness and strength. The components can be coated, for example using electroplating techniques, on exterior surfaces to enhance electrical reliability and to prevent corrosion.

Turning to Figures 6-11, the socket and the linkages and their relationship with the test equipment and the DUT will be described in further detail. The linkage includes the pivotable link 140, the elastomer 130, and the slidable mount. The pivotable link 140 is at least partially disposed within the at least one cavity 122. The pivotable link 140 extends from a first contact end 142 to a second end 146, and has an intermediate portion 144 therebetween. In one or more embodiments, the intermediate portion 144 of the link is curved and an outer surface of the elastomer 130 is rounded, and the intermediate portion 144 of the pivotable link 140 receives the elastomer therein.

The linkage is formed by a pivotable link 140 bearing against the elastomer 130, and a slidable mount 160 within the cavity 122 of the housing 120. The pivotable link 140 pivots about the slidable mount 160 so as to form an electrical connection therebetween while applying pressure to the device under test 200 at the connection pad 202. The slidable mount 160 has electrical connectors in the form of protrusions 134 that make contact with the connectors 214 on the test equipment 210 to complete the electrical circuit between the device under test 200 and the test equipment 210. In the linkage, the elastomer 130 rotationally biases the pivotable link 140 upward through the opening, but allows the pivotable link 140 to also compress the elastomer 130 when a device under test 200 is placed in the test socket assembly 100.

In one or more embodiments, the pivotable link 140 is formed with a rounded contact surface at the first contact end 142 for rolling contact with the connection pad 202 of the device under test 200 as the DUT pushes the pivotable link 140 downward into the cavity 122. FIGs. 6 and 10 illustrate the pivotable link 140 in the unloaded condition, where the elastomer 130 biases the pivotable link 140 upward (counterclockwise in Figure 3) to a position above an outer surface 132, such as an upper surface, of the housing 120 when no downward force is applied to the linkage. The pivotable link 140 includes a link pivotable structure 148 which couples with mount pivot structure 162 to form the hinge of the linkage. In one or more embodiments, the link pivotable structure 148 is also formed with a leg portion terminating in a cylindrical protuberance 150.

The slidable mount 160 includes a mount pivot structure 162. In one or more embodiments, the mount pivot structure includes a cylindrical recess that is sized to receive the cylindrical protuberance 150 of the link member to form a joint hinge. That is, the pivotable link 140 can rotate about the slidable mount 160 only in a single plane perpendicular to the longitudinal axis of the cylindrical protuberance. The slidable mount 160 further comprising PCB contact members 166, such as protrusions, that project downwardly from an underside of the slidable mount 160 through an opening in the test socket assembly 100 when there is no upward force applied to the mount (via the protrusions) from the test equipment 210. The protrusions 134 are optionally rounded and form an electrical connection with electrical connectors 214 on the test equipment 210 when the test socket assembly 100 is placed on the test equipment. The cavity 122 is sized so that, when the mount is unloaded and the protrusions 134 are disposed below the socket's lower plane as shown in FIG. 10, a gap 126 exists between the top of the mount and the top of the cavity. In one or more embodiments, a 50 micron air gap is maintained above the slidable mount 160 to insulate the probe from the high forces caused by DUT during test (FIG. 12).

FIGs. 9, 11 illustrate the condition where the housing 120 of the test socket assembly 100 is placed on the test equipment 210. The test socket assembly is coupled with the PCB, for example with screws, engaging the preload state permanently. During this mounting process, referring to FIG. 1C, the protrusions 134 make contact with the electrical connectors of the test equipment 210, and as the test socket assembly 100 is brought to bear on the test equipment 210, the slidable mount 160 is driven upward by the force of the test equipment 210. Because the elastomer 130 bears directly against the leg 172 of the slidable mount 160, a side wall 168 of the slidable mount 160 slides vertically along an inner side wall 138 and against a resisting force of the elastomer 130 and a force from the pivotable link 140 (FIG. 9). The movement of the slidable mount 160 upward in the cavity 122 reduces the gap 126 between the top of the slidable mount 160 and the top of the cavity 122, but the height of the protrusions 134 are preferably set to be less than the initial gap 126 so that the slidable mount 160 cannot make contact with the upper surface of the cavity. That is, a gap 126 is always maintained when the test socket assembly 100 is placed on the test equipment 210 despite the movement of the slidable mount 160 upward in the cavity due to the force on the protrusions 134, and the initial gap 126 exceeds a distance that the protrusions 134 downwardly project below the lower surface of the base when no upward force is applied to the protrusions. Note that the elastomer 130 resiliently forces slidable mount 160 to apply a preload to the test equipment 210 by the slidable mount 160 by the interaction of the elastomer 130, the pivotable link 140, and the slidable mount 160, resulting in a downward preload force on the electrical connector 214. In one or more embodiments, the slidable mount 160 does not move with every test cycle (when the DUT is coupled with the housing and electrical contacts), but only during the PCB mounting process. The device under test 200 is placed on the test socket assembly 100. This causes the first contact end 142 of the pivotable link 140 to rotate into the test socket assembly 100 against the force of the device under test 200. The connection pad 202 on the device under test 200 is maintained in contact with the link member's rounded upper surface by virtue of the resiliency of the elastomer 130 and the pivoting force of the slidable mount 160. Thus, an electrical path exists between the device under test 200, through the connection pad 202, through the pivotable link 140, through the slidable mount 160, through the electrical connector 214, to the test equipment 210. In this manner, solid and reliable contact is established with the DUT at each connector, which can then be measured by transmitting a signal through the test equipment.

In the absence of any upward loading on the mount by the test equipment or PCB mounting (FIG. 10), the mount 160 is simply secured in the cavity against the rear wall by the direct force of the elastomer 130 via the link member. In the free state, the probe stays in the housing by being positioned around the elastomer 130. Very little compression of the elastomer occurs at this point. The amount of protrusion in the free state of the mount allows for variability in PCB pad thicknesses.

When the slidable mount is pushed upward by affixing the socket assembly to the PCB in a preload state as shown in FIG. 11, the slidable mount 160 has a side wall 168 that slides upward vertically along the inner side wall 138 of the housing 120 until the bottom of the PCB contact members 166 are flush with the bottom of the housing 120. A compliant preload is present to ensure solid contact, and a gap 126 is maintained between the mount member and the socket cavity's upper surface to prevent compressive loads from building up in the mount member. The compliant preload on the mount's contact with the test equipment allows for mechanical tolerances that could otherwise result in small gaps between the socket and the test equipment (especially in large DUTs). In this preload state, the slidable mount 160 is pushing into the elastomer 130, which is providing a stable force in the slidable mount 160. The elastomer 130 is also holding the pivotable link 140 up to allow for contact with electrical connectors 214 of varying thicknesses.

FIG. 12 shows when the pivotable link 140 is at test. The first contact end 142 is contacted by the electrical connectors 214 and pushes the first contact end 142 within the housing 120. As this occurs, the first contact end 142 translates a distance across the pad 202, removing a thin oxide layer on the outermost surface of the connection pads 202.

FIG. 8 illustrates the PCB contact members 166 are offset from the first contact end 142 of the pivotable link 140 such that the PCB contact members 166 are not vertically aligned with the first contact end 142 of the pivotable link 140. In one or more embodiments, a method of coupling a device under test to a test apparatus with a test socket assembly is disclosed herein. The method includes disposing a device under test in the test socket assembly, the test socket assembly having a housing with at least one cavity therein, the at least one cavity having an inner side wall, an elastomer disposed within the at least one cavity, a pivotable link at least partially disposed within the at least one cavity, the pivotable link extending from a first contact end to a second end and having an intermediate portion therebetween, the second end having a link pivotable structure, the pivotable link disposed adjacent to the elastomer such that the elastomer biases the first contact end of the pivotable link towards out of the housing, a slidable mount disposed within the at least one cavity of the housing, the mount including a mount pivot structure coupled with the link pivotable structure to form a joint hinge that allows rotation of the pivotable link toward and away from the elastomer, the slidable mount having one or more PCB contact members downwardly projecting from the slidable mount, and the slidable mount disposed adjacent to the elastomer such that the elastomer biases the PCB contact members below a lower surface of the housing, the slidable mount having a side wall defined by a side wall plane, where the side wall plane is vertically slidable along the inner side wall of the housing. The method further includes placing an upward force on the slidable mount at the protrusions and causing the slidable mount to slide upward along the side wall of the at least one cavity.

In one or more embodiments, the method further includes providing a compliant force on the pivoting link and the sliding mount in a same time period. For example, after the test socket assembly is mounted to the PCB, and while a DUT is placed in the test socket assembly and being tested. In one or more embodiments, the pivotable link provides a force to the device under test more than 80% independent from force provided by the slidable mount. In one or more embodiments, the slidable mount provides non-scrub force on a PCB side of the test socket assembly.

The test contact assembly can be produced at low cost and has superior electrical performance and mechanical reliability. The assembly has a short overall length for good electrical performance with low inductance and high mechanical compliance. The single elastomer provides a stable force on both the link and the mount, and is durable over a long period of time. Using the single elastomer top provide compliance on both elements achieves a unique force-balance system. The contact point of the link scrubs through oxide layers of the device under test to make electrical contact. The contact point of the mount has a non-scrub force in order to avoid scrubbing the PCB and avoid early deterioration of the PCB. The optional single elastomer achieves independent compliance for the mount and link. The offset can be varied without disruption of the force balance. Once the socket is affixed to the PCB, there is a constant downward force provided from the elastomer to make a stable contact.

The terms“upward”,“downward” and“vertical” are not limited to strictly up and down movements, or vertical movements, for example if the test contact assembly is used at an angle. The terms are illustrative of the movements of one or more components relative to other components.

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 for coupling a device under test to a test apparatus, the test socket assembly comprising:

a housing having at least one cavity therein, the at least one cavity having an inner side wall;

an elastomer disposed within the at least one cavity;

a pivotable link at least partially disposed within the at least one cavity, the pivotable link extending from a first contact end to a second end and having an intermediate portion therebetween, the second end having a link pivotable structure;

the pivotable link disposed adjacent to the elastomer such that the elastomer biases the first contact end of the pivotable link towards out of the housing;

a slidable mount disposed within the at least one cavity of the housing, the slidable mount including a mount pivot structure coupled with the link pivotable structure to form a joint hinge that allows rotation of the pivotable link toward and away from the elastomer;

the slidable mount having one or more PCB contact members downwardly projecting from the slidable mount; and

the slidable mount disposed adjacent to the elastomer such that the elastomer biases the PCB contact members toward out of the housing, the slidable mount having a side wall defined by a side wall plane, where the side wall plane is vertically slidable along the inner side wall of the housing.

2. The test socket assembly as recited in claim 1, wherein the link pivotable structure is an at least partially cylindrical component, and the mount pivot structure is a cylindrical recess that receives the at least partially cylindrical component therein.

3. The test socket assembly as recited in any one of claims 1 - 2, wherein the PCB contact members are offset from the first contact end of the pivotable link such that the PCB contact members are not vertically aligned with the first contact end of the pivotable link.

4. The test socket assembly as recited in any one of claims 1 - 3, wherein the pivotable link provides a force to the device under test more than 80% independent from force provided by the slidable mount.

5. The test socket assembly as recited in c any one of claims 1 - 4, wherein the slidable mount provides non-scrub force on a PCB side of the test socket assembly.

6. The test socket assembly as recited in any one of claims 1 - 5, wherein the intermediate portion of the pivotable link is curved and an outer surface of the elastomer is rounded, and the intermediate portion of the pivotable link receives the elastomer therein.

7. The test socket assembly as recited in any one of claims 1 - 6, wherein a height of the at least one cavity above the slidable mount creates a gap between a socket upper wall and an upper surface of the slidable mount, the gap having a vertical spacing that exceeds a distance that the PCB contact members downwardly project below a lower surface of the test socket assembly in absence of an applied upward force to the PCB contact members.

8. The test socket assembly as recited in any one of claims 1 - 7, wherein a compliant force is placed on the pivotable link and the slidable mount in a same time period.

9. The test socket assembly as recited in any one of claims 1 - 8, wherein the elastomer is a single elastomer that provides force directly to both the slidable mount and the pivotable link.

10. A test socket assembly for coupling a device under test to a test apparatus, the test socket assembly comprising:

an elastomer disposed within the at least one cavity;

the pivotable link disposed adjacent to the elastomer such that the elastomer rotationally biases the first contact end of the link to a position above an outer surface of the test socket assembly in the absence of a force applied on the first contact end; and

a slidable mount disposed within the at least one cavity of the housing, the slidable mount including a mount pivot structure coupled with the link pivotable structure to form a joint hinge that allows rotation of the pivotable link toward and away from the elastomer in a single plane of the pivotable link, the slidable mount having one or more PCB contact members downwardly projecting from the slidable mount below a second outer surface of the housing in absence of a force applied to the PCB contact members toward the housing, the slidable mount having a side wall defined by a side wall plane, where the side wall plane is vertically slidable along the inner side wall of the housing.

11. The test socket assembly as recited in claim 10, wherein the pivotable link provides a force to the device under test more than 80% independent from force provided by the slidable mount.

12. The test socket assembly as recited in any one of claims 10 - 11, wherein the link pivotable structure is an at least partially cylindrical component, and the mount pivot structure is a cylindrical recess that receives the at least partially cylindrical component therein.

13. The test socket assembly as recited in any one of claims 10 - 12, wherein the PCB contact members are offset from the first contact end of the pivotable link such that the PCB contact members are not vertically aligned with the first contact end of the pivotable link.

14. The test socket assembly as recited in any one of claims 10 - 13, wherein the slidable mount provides non-scrub force on a PCB side of the test socket assembly.

15. The test socket assembly as recited in any one of claims 10 - 14, wherein the intermediate portion of the link is curved and an outer surface of the elastomer is rounded, and the intermediate portion of the link receives the elastomer therein.

16. The test socket assembly as recited in any one of claims 10 - 15, wherein a height of the at least one cavity above the slidable mount creates a gap between a socket upper wall and an upper surface of the slidable mount, the gap having a vertical spacing that exceeds a distance that the PCB contact members downwardly project below the second outer surface of the socket in the absence of an applied upward force to the PCB contact members.

17. The test socket assembly as recited in any one of claims 10 - 16, wherein a compliant force is placed on the pivotable link and the slidable mount in a same time period.

18. The test socket assembly as recited in any one of claims 10 - 17, wherein the elastomer is a single elastomer that provides force directly to both the slidable mount and the pivotable link.

19. A method of coupling a device under test to a test apparatus with a test socket assembly, the method comprising:

disposing a device under test in the test socket assembly, the test socket assembly having a housing with at least one cavity therein, the at least one cavity having an inner side wall, an elastomer disposed within the at least one cavity, a pivotable link at least partially disposed within the at least one cavity, the pivotable link extending from a first contact end to a second end and having an intermediate portion therebetween, the second end having a link pivotable structure, the pivotable link disposed adjacent to the elastomer such that the elastomer biases the first contact end of the pivotable link towards out of the housing, a slidable mount disposed within the at least one cavity of the housing, the slidable mount including a mount pivot structure coupled with the link pivotable structure to form a joint hinge that allows rotation of the pivotable link toward and away from the elastomer, the slidable mount having one or more PCB contact members downwardly projecting from the slidable mount, and the slidable mount disposed adjacent to the elastomer such that the elastomer biases the PCB contact members below a lower surface of the housing, the slidable mount having a side wall defined by a side wall plane, where the side wall plane is vertically slidable along the inner side wall of the housing; and

placing an upward force on the slidable mount at the PCB contact members and causing the slidable mount to slide upward along the side wall of the at least one cavity.

20. The method as recited in claim 19, further comprising placing a downward force on the pivotable link and causing the pivotable link to pivot about the link pivotable structure.

21. The method as recited in any one of claims 19 - 20, further comprising providing a compliant force on the pivoting link and the sliding mount in a same time period.