Compliance probe contact assembly and test system having same

Abstract

A compliant probe contact assembly and a test system having the same are provided, the compliant probe contact assembly for a test system for testing an integrated circuit device. The contact assembly includes an upper plunger including a first shoulder separating an upper shaft from a lower shaft, and a retainer adjacent an end of the lower shaft. The contact assembly also includes a first receiver and a second receiver configured to engage with the upper plunger, each of the first receiver and the second receiver including a second shoulder having a shoulder stop. The contact assembly also includes a biasing member. When the contact assembly is assembled, the biasing member is captured between the bottom of the first shoulder and the shoulder stop of the first receiver and the shoulder stop of the second receiver. An upper plunger separates a side portion of an upper portion of the first receiver from a side portion of an upper portion of the second receiver. A side portion of the lower portion of the first receiver and a side portion of the lower portion of the second receiver are in contact with each other.

Description

Technical Field

[0001] The present disclosure generally relates to the field of testing microcircuits (e.g., chips such as semiconductor devices, integrated circuits, etc.). More specifically, the present disclosure relates to a spring-loaded probe contact assembly that provides electrical connection to a device under test (DUT). Background Art

[0002] The manufacturing process for microcircuits cannot guarantee that each microcircuit is fully functional. The size of an individual microcircuit is microscopic, and the process steps are very complex, so small glitches or minor faults during the manufacturing process often result in defective devices. Installing a defective microcircuit on a circuit board is relatively expensive. Installation typically involves soldering the microcircuit to the circuit board. Once installed on the circuit board, removing the microcircuit is problematic because the action of remelting the solder may damage the circuit board. Thus, if the microcircuit is defective, the circuit board itself may be damaged, meaning that all the value added to the circuit board up to that point is lost. For all these reasons, microcircuits are typically tested before being installed on a circuit board. Each microcircuit must be tested in a way that identifies all defective devices, but also does not incorrectly identify good devices as defective. Either type of error adds a significant total cost to the circuit board manufacturing process if it occurs frequently.

[0003] Microcircuit test equipment itself is rather complex. First, the test equipment must make precise and low-resistance temporary and non-destructive electrical contact with each of the closely spaced microcircuit contacts. Due to the small size of the microcircuit contacts and the spacing between them, even small errors in forming the contacts will result in incorrect connections. Another problem in microcircuit test equipment occurs in automated testing. The test equipment can test a hundred devices per minute, or even more. The large number of tests results in wear on the tester contacts, thus forming an electrical connection to the microcircuit terminals during testing.

[0004] There are other considerations. Inexpensive tester contacts that perform well are advantageous. Since test equipment is expensive, it is also desirable to minimize the time required to replace them. If the test equipment is offline for an extended period of normal maintenance, the cost of testing an individual microcircuit increases. Currently used test equipment has an array of test contacts that mimics the pattern of the microcircuit terminal array. The test contact array is supported in a structure that precisely holds the contacts aligned relative to each other. The test contacts are mounted on a load board (i.e., a printed circuit board (PCB)) having conductive pads that are electrically connected to the test contacts. The load board pads are connected to a circuit path that conveys signals and power between the test equipment electronics and the test contacts. Summary of the Utility Model

[0005] Test contactors are typically designed and constructed using spring-loaded contacts because the receptacle design is simple and the electrical contacts for ball grid array (BGA) packages and / or other array-type integrated circuit packages remain robust and reliable. The spring-loaded contacts form a temporary electrical connection between the DUT and the load board. Each contact (or contact assembly) connects a specific terminal on the DUT (e.g., a signal and power (S&P) terminal) to a specific pad on the load board. It should be understood that the DUT can have a BGA package or any other suitable package(s). For example, the DUT can be a pad device, a peripheral device, etc.

[0006] The embodiments disclosed herein provide solutions to each of the above problems. The embodiments disclosed herein provide a compliant spring-loaded probe contact assembly that includes an upper plunger (DUT plunger) and a pair of receivers (also referred to as lower plungers, PCB plungers, or load board plungers) that are clamped by a biasing member such as a compliant compression spring. The probe contact assemblies disclosed herein can provide significant improvements over existing designs to enhance the electrical and mechanical performance of spring-loaded probes. The probe contact assemblies disclosed herein can use a variety of manufacturing techniques to fabricate the plunger components of the spring-loaded probe contact assembly, and the probe contact assembly is not limited to using a single technique. The probe contact assemblies disclosed herein are capable of using a homogeneous alloy DUT-side tip and using two identical PCB-side plunger components that are fabricated by a planar forming process (e.g., etching, stamping, waterjet cutting, or e-forming). Due to electrical redundancy, using two PCB-side plunger assemblies that contact the PCB pads may be beneficial.

[0007] The internal geometry of the probe contact assembly can be designed such that the geometry (e.g., the internal geometry of the spring) can capture and hold components (e.g., within the internal volume of the spring) while forming a reliable sliding interconnect between the upper plunger and the receiver pair. The probe contact assemblies disclosed herein do not rely on deforming, curling, snapping one (or more) latches, or press-fitting springs. For the probe contact assemblies disclosed herein, when the probe contact assembly is assembled, the geometry of the components can capture the probe contact assembly by itself, and the probe contact assembly may not physically disengage itself during normal use.

[0008] The probe contact assemblies disclosed herein can reduce the overall length of the assembly, which can reduce probe inductance and improve radio frequency (RF) performance. In contrast, existing latch and press-fit techniques may require an extended length region to achieve forced latching or features that are large enough to allow curling or deformation to hold the assembly together reliably.

[0009] The probe contact assembly disclosed herein can be used in the most common precision machined standard socket housings, can be extremely miniaturized, and may be necessary for testing 5G and other high-frequency semiconductor devices due to its inherent low inductance. The external spring geometry and internal component design of the probe contact assembly can allow for a large percentage of compliance in the probe contact assembly, which is important for testing BGA packages or when testing multiple DUTs at once due to additional mechanical tolerances in the test system.

[0010] The probe contact assembly disclosed herein can have components captured within a spring volume, which ensures that sliding interfaces (e.g., between the side of the receiver and the inner shaft of the upper plunger) are always in contact with each other. The mating of these components can ensure reliable electrical contact of the plunger, and the receiver can contact the inner wire surface of the spring, which may be desirable as a redundant contact element in the system and can minimize the likelihood of RF resonance that may occur at undesired frequencies.

[0011] Also disclosed is a compliant probe contact assembly for a test system for testing integrated circuit devices. The contact assembly includes an upper plunger and a retainer, the upper plunger including a first shoulder separating an upper shaft from a lower shaft, the retainer being adjacent an end of the lower shaft. The contact assembly also includes a first receiver and a second receiver configured to engage the upper plunger, each of the first receiver and the second receiver including a second shoulder having a shoulder stop. The contact assembly also includes a biasing member. When the contact assembly is assembled, the biasing member is captured between the bottom of the first shoulder and the shoulder stops of the first receiver and the second receiver. The upper plunger separates the sides of the upper portions of the first receiver and the second receiver. The sides of the lower portions of the first receiver and the second receiver are in contact with each other.

[0012] Also disclosed is a test system for testing an integrated circuit device. The test system includes a device under test (DUT), a load board, and a compliant probe contact assembly. The contact assembly includes an upper plunger and a retainer. The upper plunger includes a first shoulder separating an upper shaft from a lower shaft. The retainer is adjacent to an end of the lower shaft. The contact assembly further includes a first receiver and a second receiver configured to engage with the upper plunger. Each of the first receiver and the second receiver includes a second shoulder having a shoulder stop. The contact assembly further includes a biasing member. When the contact assembly is assembled, the biasing member is captured between the bottom of the first shoulder and the shoulder stops of the first receiver and the second receiver. The upper plunger separates the sides of the upper portions of the first receiver and the second receiver. The sides of the lower portions of the first receiver and the second receiver are in contact with each other. The upper plunger includes a DUT interface configured to engage with the DUT. The ends of the first receiver and the second receiver are configured to engage with the load board.

[0013] Also disclosed is a compliant probe contact assembly for a test system for testing an integrated circuit device. The contact assembly includes a plunger having a retainer adjacent to an end of a lower shaft; and a first receiver plate and a second receiver plate having a top and a bottom, each receiver plate having a longitudinal aperture sized to receive only a portion of the retainer, the width of the aperture being insufficient to allow the retainer to pass therethrough. The contact assembly further includes a biasing member. The first receiver plate and the second receiver plate are aligned relative to each other such that the first receiver plate and the second receiver plate are gradually closer to each other at the bottom relative to the top. When the contact assembly is assembled, the biasing member surrounds at least a portion of the plunger and receives the first receiver plate and the second receiver plate such that the first receiver plate, the second receiver plate, and the retainer remain in physical and electrical contact as the plunger moves along the apertures of the first receiver plate and the second receiver plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The drawings, which are incorporated in and constitute a part of this disclosure, illustrate embodiments of the systems and methods described in this specification and, together with the description, serve to explain the principles of the disclosure.

[0015] Figure 1A is a perspective view of a part of a test system for receiving a DUT for testing, according to one embodiment.

[0016] Figure 1B is a bottom perspective view of a DUT, according to one embodiment.

[0017] Figure 1C is a side view of a part of a test system for receiving a DUT, according to one embodiment.

[0018] Figure 1D is a side view of a Figure 1C test system according to one embodiment, in which the DUT is electrically engaged.

[0019] Figure 2A is a side view of an upper plunger of a probe contact assembly for a test system according to one embodiment.

[0020] Figure 2B is a Figure 2A perspective view of an upper plunger according to one embodiment.

[0021] Figure 3A is a front view of a receiver of a probe contact assembly for a test system according to one embodiment.

[0022] Figure 3B is a Figure 3A perspective view of a receiver according to one embodiment.

[0023] Figure 4A is a side view of a spring of a probe contact assembly for a test system according to one embodiment.

[0024] Figure 4B is a Figure 4A perspective view of a spring according to one embodiment.

[0025] Figure 5A is a front view of a probe contact assembly for a test system according to one embodiment.

[0026] Figure 5B is a Figure 5A side view of a probe contact assembly according to one embodiment.

[0027] Figure 5C is a Figure 5A perspective view of a probe contact assembly according to one embodiment.

[0028] Figure 5D is a Figure 5A top view of a probe contact assembly according to one embodiment.

[0029] Figure 5E is a Figure 5A bottom view of a probe contact assembly according to one embodiment.

[0030] Figure 6A is a front view of a probe contact assembly (in a compressed state) for a test system according to another embodiment.

[0031] Figure 6B is a Figure 6A side view of a probe contact assembly according to another embodiment.

[0032] Figure 6Cis according to another embodiment Figure 6A Perspective view of the probe contact assembly of

[0033] Figure 6D is according to another embodiment Figure 6A Top view of the probe contact assembly of

[0034] Figure 6E is according to another embodiment Figure 6A Bottom view of the probe contact assembly of

[0035] Figure 7A Top view of the probe contact assembly for a test system according to one embodiment

[0036] Figure 7B is according to one embodiment Figure 7A Front view of the probe contact assembly of

[0037] Figure 7C is according to one embodiment Figure 7A Cross-sectional view of the probe contact assembly of along line A-A

[0038] Figure 7D is according to one embodiment Figure 7A Cross-sectional view of the probe contact assembly of along line B-B

[0039] Figure 8A Top view of the probe contact assembly (in a compressed state) for a test system according to another embodiment

[0040] Figure 8B is according to another embodiment Figure 8A Front view of the probe contact assembly of

[0041] Figure 8C is according to another embodiment Figure 8A Cross-sectional view of the probe contact assembly of along line C-C

[0042] Figure 8D is according to another embodiment Figure 8A Cross-sectional view of the probe contact assembly of along line D-D

[0043] Figure 9A Front view of the probe contact assembly for a test system according to one embodiment

[0044] Figure 9B is according to one embodiment Figure 9A Cross-sectional view of the probe contact assembly of along line E-E

[0045] Figure 10A Cross-sectional perspective view of a plurality of probe contact assemblies housed in a socket housing according to one embodiment

[0046] Figure 10B According to an embodiment Figure 10A FIG. 1 is an enlarged view of a portion F1 of FIG. 1 , showing a probe contact assembly housed in a contact cavity of a socket housing.

[0047] Figure 11A is a cross-sectional perspective view of a plurality of probe contact assemblies (in a compressed state) housed in a socket housing according to another embodiment.

[0048] Figure 11B According to another embodiment Figure 11A FIG. 2 is an enlarged view of portion F2 of FIG. 3 , showing the probe contact assembly housed in the contact cavity of the socket housing.

[0049] Figure 12A is a front view of a receiver (in a flat state during manufacture) of a probe contact assembly for a test system according to another embodiment.

[0050] Figure 12B According to another embodiment Figure 12A A perspective view of the receiver in a folded state.

[0051] Figure 13A is a perspective view of a probe contact assembly according to one embodiment.

[0052] Figure 13B is a perspective view of a probe contact assembly in a compressed state according to another embodiment.

[0053] Figure 14A is a front view of a receiver (in a flat state during manufacture) of a probe contact assembly for a test system according to yet another embodiment.

[0054] Figure 14B According to yet another embodiment Figure 14A A perspective view of the receiver in a folded state.

[0055] Figure 15A is a perspective view of a probe contact assembly according to one embodiment.

[0056] Figure 15B is a perspective view of a probe contact assembly in a compressed state according to another embodiment.

[0057] Figure 16A is a front view of a receiver of a probe contact assembly for a test system according to yet another embodiment.

[0058] Figure 16B According to yet another embodiment Figure 16A A perspective view of a receiver.

[0059] Figure 17A is a front view of a probe contact assembly according to one embodiment.

[0060] Figure 17B is according to one embodiment Figure 17A side view of the probe contact assembly.

[0061] Figure 17C is according to one embodiment Figure 17A perspective view of the probe contact assembly.

[0062] Figure 17D is a front view of a probe contact assembly in a compressed state according to another embodiment.

[0063] Figure 17E is according to another embodiment Figure 17D side view of the probe contact assembly.

[0064] Figure 17F is according to another embodiment Figure 17D perspective view of the probe contact assembly.

[0065] Like reference numerals always denote like parts. DETAILED DESCRIPTION

[0066] A test contactor (i.e., part of a test assembly including an alignment plate, socket, etc.) can typically provide an electrical connection to a DUT by making metal-to-metal contact with a printed circuit board (e.g., a load board, including S&P terminals of the load board), the DUT including S&P terminals of the DUT. A compliant contact assembly has an advantage in testing by accommodating DUT package variations. It should be understood that the term "compliant" can refer to the property of a material to undergo elastic deformation or volume change when subjected to an applied force. Compliance can be equal to the reciprocal of stiffness.

[0067] Terminals of the DUT can be temporarily electrically connected to corresponding contact pads on the load board through a series of conductive contacts. The terminals can be pads, balls, wires (leads), or other contact points. Each terminal is connected to a contact that is electrically connected to a corresponding contact pad on the load board.

[0068] The embodiments disclosed herein provide a spring-loaded probe contact assembly having high performance (e.g., high RF performance, etc.), low inductance, and low cost. The height of the contact assembly can be scalable. In one embodiment, the height of the contact assembly can be one millimeter or about one millimeter, and the diameter of the contact assembly or spring can be from 100 microns or about 100 microns to 250 microns or about 250 microns.

[0069] Figure 1AIs a perspective view of a part of a test system 100 for accommodating a DUT 110 for testing according to one embodiment.

[0070] The test system 100 includes a test component 120 for a DUT (e.g., a microcircuit, etc.) 110. The test component 120 includes a load board 170 that supports an alignment board 160 having an opening or aperture 130. The alignment board precisely defines the X and Y positioning of the DUT 110 in the test component 120 (see the coordinate indicators X and Y, where the coordinate X is perpendicular to the coordinate Y, and the coordinate Z is perpendicular to the plane of X and Y). If the DUT 110 has orientation features, it is common practice to include cooperating features in the aperture 130. The load board 170 carries connection pads on its surface, and the pads are connected to a cable 180 through signal and power (S&P) conductors. The cable 180 is connected to an electronic device that performs electrical tests on the DUT 110. If the test electronic device is integrated with the test component 120, the cable 180 can be very short, or even inside the test component 120. Or if the test electronic device is on a separate chassis, the cable 180 can be longer. It should be understood that the cable 180 can be optional. In another embodiment, the load board can be connected to the test electronic device through any other suitable mechanism (including but not limited to, for example, spring-loaded probes).

[0071] A test contact array 140 having a plurality of individual test contact elements precisely mirrors the S&P terminals carried on the surface of the DUT 110 (see Figure 1B 112 in). When the DUT 110 is inserted into the aperture 130, the S&P terminals of the DUT 110 are precisely aligned with the test contact array 140. The test component 120 is designed to be compatible with the test contact array 140 that includes the device. The test contact array 140 is carried on a socket 150. Each test contact in the array 140 is preferably formed on and in the socket 150 using well-known photolithography and laser machining processes. The socket 50 has alignment features, such as holes or edge patterns in the area between the alignment board 160 and the load board 170, which provide precise alignment of the socket 150 with corresponding protruding features on the alignment board 160. All the test contacts 140 are precisely aligned with the alignment features of the socket 150. In this way, the test contacts in the array 140 are placed to be precisely aligned with the aperture 130.

[0072] Figure 1B Is a bottom perspective view of a DUT 110 according to one embodiment. The DUT (e.g., a microcircuit, etc.) 110 includes a top main surface (not shown) and in the Z (see Figure 1AA bottom main surface 114 opposite to the top main surface in the directions of the coordinate indicators X, Y, and Z). In one embodiment, the DUT 110 may have a BGA package. In some embodiments, the DUT 110 may have a land grid array (LGA) package, such as quad flat no-lead (QFN) and dual flat no-lead (DFN). Land grid array, also known as micro lead frame (MLF) and small outline no-lead (SON), is a surface mount technology and is one of several packaging technologies for connecting the DUT 110 to the surface of, for example, a socket 150 or other printed circuit board (PCB) without vias. In one embodiment, the land grid array may be a near chip-scale plastic package made of a planar copper lead frame substrate. Peripheral lands (e.g., terminals 112) on the bottom of the package provide electrical connection to the socket 150 or PCB. The land grid array package may include exposed thermal vias to improve heat transfer from the DUT 110 (e.g., into the PCB). The QFN package may be similar to the quad flat package (QFP). In one embodiment, the DUT 110 may be a wafer-level chip scale package (WL-CSP), a leaded package (such as thin small outline package (TSOP) or diode outline (DO) package), etc.

[0073] Figure 1C is a side view of a part of a test system 100 for receiving the DUT 110 according to one embodiment. Figure 1D is according to one embodiment of Figure 1C the test system 100 in a side view, where the DUT 110 is electrically bonded.

[0074] As Figure 1C shown, the DUT 110 is placed on the test assembly 120, electrical tests are performed, and then the DUT 110 is removed from the test assembly 120. Any electrical connections are formed by pressing components into electrical contact with other components; there is no soldering or desoldering at any point during the testing of the DUT 110. The entire electrical testing process may last only about an instant, such that the quick and accurate placement of the DUT 110 becomes important for ensuring that the test system 100 is used efficiently. High throughput of the test assembly 120 typically requires automated handling of the DUT 110. In most cases, an automated mechanical system places the DUT 110 on the test assembly 120 before testing and removes the DUT 110 once the testing is complete. The handling and placement mechanism may use mechanical and optical sensors to monitor the position of the DUT 110 and use a combination of translational and rotational actuators to align and place the DUT 110 on or in the test assembly 120. Alternatively, the DUT 110 may be placed by hand or by a combination of manual feeding and automated equipment.

[0075] The DUT 110 typically includes signal and power terminals 112 that are connected to a socket 150 or other PCB (see also Figure 1B for terminals 112). The terminals can be on one side of the DUT 100 or can be on both sides of the DUT 110. For use in the test assembly 120, all terminals 112 should be accessible from one side of the DUT 110, although it is understood that there may be one or more components on the opposite side of the DUT 110, or other components and / or terminals on the opposite side that may not be testable by accessing the terminals 112. Each terminal 112 is formed as a small solder pad on the button side of the DUT 110 or may be formed as a lead (e.g., hemispherical) protruding from the body of the DUT 110. Prior to testing, the pad or lead 112 is attached to an electrical lead that is internally connected to other leads, other electrical components, and / or one or more chips in the DUT. The volume and dimensions of the pad or lead can be very precisely controlled, and there are generally no significant difficulties caused by dimensional variations or placement variations from pad to pad or lead to lead. During testing, the terminals 112 remain solid state, and there is no melting or reflow of any solder.

[0076] The terminals 112 can be arranged in any suitable pattern on the surface of the DUT 110. In some cases, the terminals 112 can be a substantially square grid, which is the origin of the description of leaded components such as the DUT 110, BGA, WL-CSP, QFN, DFN, TSOP, or DO. There may also be deviations from the rectangular grid, including irregular spacing and geometries. It should be understood that the specific positions of the terminals can be changed as needed, where the corresponding positions of the pads on the load board 170 and the contacts on the socket 150 or housing are selected to match the positions of the terminals 112. Typically, the spacing between adjacent terminals 112 is in the range of 0.25 mm to 1.5 mm, where this spacing is commonly referred to as the "pitch". When viewed from the side, as Figure 1C shown, the DUT 110 shows a row of terminals 112 that can optionally include gaps and irregular spacing. These terminals 112 are made substantially flat or as flat as possible using typical manufacturing processes. In many cases, if there are chips or other components on the DUT 110, the protrusion of the chips is typically less than the protrusion of the terminals 112 away from the DUT 110.

[0077] Figure 1CThe test assembly 120 includes a load board 170 (PCB board). The load board 170 includes a load board substrate 174 and circuitry for electrically testing the DUT 110. Such circuitry can include drive electronics capable of generating one or more AC voltages having one or more specific frequencies, and sense electronics capable of sensing the response of the DUT 110 to such drive voltages. Sensing can include detecting current and / or voltage at one or more frequencies. Generally, it is highly desirable for the features on the load board 170 to be aligned with the corresponding features on the DUT 110 when installed. Generally, both the DUT 110 and the load board 170 are mechanically aligned with one or more positioning features on the test assembly 120. The load board 170 can include one or more mechanical positioning features, such as fiducials or precisely located holes and / or edges, which ensure that the load board 170 can be accurately positioned on the test assembly 120. These positioning features generally ensure the lateral alignment (X, Y, see Figure 1A ), and / or the longitudinal alignment (Z, see Figure 1A ).

[0078] Generally, the load board 170 can be a relatively complex and expensive component. The housing / test assembly 120 performs many functions, including protecting the contact pads 172 of the load board 170 from wear and damage. Such an additional element can be a plug-in socket 150. The socket 150 is also mechanically aligned with the load board 170 by suitable positioning features (not shown) and is located in the test assembly 120 above the load board 170, facing the DUT 110. The socket 150 includes a series of conductive contacts 152 that extend longitudinally outward on either side of the socket 150. Each contact 152 can include an elastic element, such as a spring, elastomer, or other suitable material, and is capable of conducting current from the DUT 110 to the load board 170 / from the load board to the DUT 110 with a sufficiently low resistance or impedance. Each contact 152 can be a single conductive unit or can alternatively be formed as a combination of conductive elements. Each contact 152 connects one contact pad 172 on the load board 170 to one terminal 112 on the DUT 110, although there can be test scenarios where one or more contact pads 172 are connected to a single terminal 112 or multiple terminals 112 are connected to a single contact pad 172. In the text and drawings, we assume that a single contact 152 connects a single pad 172 to a single terminal 112, although it can be understood that any tester element disclosed herein can be used to connect one or more contact pads 172 to a single terminal 112, or one or more terminals 112 to a single contact pad 172. Note that this contact forms an electrical connection 154 between the terminal 112 and the contact pad 172.

[0079] Typically, socket 150 is electrically connected to load board pad 172 and the bottom contact surface of DUT 110. Although socket 150 can be removed and replaced relatively easily compared to the removal and replacement of load board 170, for the purposes herein, we consider socket 150 to be part of test assembly 120. During operation, test assembly 120 includes load board 170, socket 150, and a mechanical structure (not shown) that mounts them and holds them in place. Each DUT 110 is placed against test assembly 120, electrically tested, and removed from test assembly 120. A single socket 150 can test many DUTs 110 before it wears out and can typically last for thousands or more tests before replacement is needed. Generally, it is desirable for the replacement of socket 150 to be relatively quick and simple so that test assembly 120 only experiences a small amount of downtime for socket replacement. In some cases, the speed of replacing socket 150 may even be more important than the actual cost of each socket 150, where an increase in tester working time results in cost savings during operation.

[0080] Figure 1C The relationship between test assembly 120 and DUT 110 is shown. When testing each DUT 110, it is placed into a suitable robotic handler with placement characteristics precise enough so that specific terminals 112 on DUT 110 can be placed precisely and reliably relative to corresponding contacts 152 on socket 150 and corresponding contact pads 172 on load board 170 (in X, Y, and Z, see Figure 1A ). A robotic handler (not shown) forces each DUT 110 into contact with test assembly 120. The magnitude of the force depends on the exact configuration of the test, including the number of terminals 112 being tested, the force applied to each terminal, typical manufacturing and alignment tolerances, etc. Generally, the force is applied by a mechanical manipulator (not shown) of the tester and acts on DUT 110. Generally, this force is typically longitudinal and is typically normal to load board 170.

[0081] Figure 1D The contact between test assembly 120 and DUT 110 is shown, where sufficient force is applied to DUT 110 to engage contacts 152 and form electrical connection 154 between each terminal 112 and its corresponding contact pad 172 on load board 170.

[0082] Figure 2A is a side view of upper plunger 200 of a probe contact assembly for a test system according to an embodiment. Figure 2B is according to an embodiment Figure 2A of upper plunger 200. It should be understood that the probe contact assembly (e.g., Figure 1C and 1DThe contact 152) can be a compliant spring-loaded probe contact assembly.

[0083] In an embodiment (e.g., see Figures 5A to 5C ), the probe contact assembly includes an upper plunger 200 (DUT plunger), a biasing member 400 (shown as a compliant compression spring), and a pair of receivers 300 (also referred to as lower plungers, PCB plungers, or load board plungers). It should be understood that the receivers can preferably be the same or matching pairs, but not necessarily so. It should also be understood that in one embodiment, the biasing member 400 can be a spring or other object other than a spring that can provide the required elasticity. The top of the upper plunger 200 is configured to engage the signal and power (S&P) terminals of the DUT. It should be understood that the S&P terminals of the DUT can be pins, pads, leads, balls, wires, etc. In one embodiment, the top of the upper plunger 200 is configured to engage the solder balls of a ball grid array (BGA) package. The bottom or bottoms of the receivers 300 are configured to engage the signal and power (S&P) terminals of a PCB (i.e., load board). It should be understood that the S&P terminals of the PCB can be pins, pads, leads, wires, etc. In one embodiment, the bottom of the receivers 300 is configured to engage a pad on the PCB that is in electrical contact with the test equipment. It should be understood that the receivers 300 can be two separate identical parts or a single-piece integral part.

[0084] Returning to Figure 2A and 2B , in one embodiment, the upper plunger 200 includes a DUT interface 210 (the top of the upper plunger 200), a DUT side shaft 220, a shoulder 230, an inner shaft 240, and a retainer 250. In one embodiment, the retainer 250 includes an end 260.

[0085] In one embodiment, the DUT interface 210 can be a crown interface configured to engage BGA balls (the S&P terminals of the DUT). In other embodiments, the shape of the DUT interface 210 can be conical, spire-shaped, circular, flat, etc., depending on the interface type of the DUT terminals.

[0086] In one embodiment, the DUT side shaft 220 can have a cylindrical shape or other suitable shape. The diameter of the shoulder 230 is greater than the diameter of the DUT side shaft 220. The shoulder 230 can be configured to stop the upper plunger 200 in the socket housing (see the detailed description in Figures 10A to 11B ) in the height direction (vertical direction or Z direction) of the probe contact assembly (see Figure 1A) movement on the [object] so that the probe contact assembly can be held in the socket housing. In one embodiment, the shoulder 230 extends from the DUT side shaft 220, where the size / diameter of the shoulder 230 gradually increases and then gradually decreases towards the inner shaft 240. In one embodiment, the maximum width or diameter of the shoulder 230 can be the same as or close to the outer diameter of the spring 400, or between the outer diameter of the spring 400 and the inner diameter of the spring 400.

[0087] In one embodiment, the inner shaft 240 can be configured as a contact interface to a mating receiver (e.g., a planar receiver) 300, which can slide along the length of the inner shaft 240 and form an electrical contact. The diameter of the inner shaft 240 is smaller than the diameter of the shoulder 230 (and the diameter of the DUT side shaft 220). In one embodiment, the inner shaft 240 can have a cylindrical shape or other suitable shape.

[0088] The retainer 250 is configured to hold the probe contact assembly together. In one embodiment, the retainer 250 can have a knob shape or other suitable shape, which can be partially received in the orifice 320 of the receiver 300 (see Figure 3A and 3B ). The end 260 of the retainer 250 can have a tapered chamfered end that facilitates the assembly of the probe contact assembly. In one embodiment, the retainer 250 extends from the inner shaft 240, where the size / diameter of the retainer 250 gradually increases and then gradually decreases towards the conical chamfered end 260. It should be understood that the diameter of the retainer 250 can be greater than the width of the orifice 300 to prevent the retainer 250 from passing through. The size of a part of the conical end 260 can be designed to be partially received within the orifice 320 so that when the upper plunger is pushed (e.g., by the DUT), the conical end 260 can slide along the orifice. This sliding preferably occurs in the inner circumferential surface of the orifice 320. The end 260 does not have to be conical, but can be any shape that further is a) a partial passage through the orifice 320, and b) slides along the inner surface with minimal friction, but has complete electrical integrity and / or contact. The angle between the receiver 300 and the end 260 can further achieve this purpose.

[0089] Returning to Figure 2A and 2B, in one embodiment, the diameter of the shoulder 230 can be 80% or about 80% of the minimum DUT pitch. The minimum DUT pitch can refer to the center-to-center spacing between the closest adjacent S&P terminals of the DUT. The minimum DUT pitch can be 300 microns or about 300 microns. The gap between the closest adjacent S&P terminals of the DUT can be 30 microns or about 30 microns. The diameter of the inner shaft 240 can be 50% or about 50% of the diameter of the shoulder 230. The diameter of the retainer can be 20% or about 20% larger than the diameter of the inner shaft 240. When the spring 400 is fully compressed, the length of the inner shaft 240 can be 10% or about 10% longer than the length of the spring 400 (see Figure 4A and 4B ).

[0090] In one embodiment, the upper plunger 200 can be computer numerically controlled (CNC) turned on an automatic lathe. The upper plunger 200 can be electroplated or made of a solid metal or alloy material, such as a homogeneous alloy including copper alloy, palladium alloy, etc. In one embodiment, the upper plunger 200 can be composed of flat metal elements. In one embodiment, the upper plunger 200 can be electroplated with gold or other conductive materials. In one embodiment, the height of the upper plunger 200 can be 500 microns or about 500 microns to 600 microns or about 600 microns.

[0091] Figure 3A is a front view of the receiver 300 of the probe contact assembly for a test system according to one embodiment. Figure 3B is according to one embodiment of Figure 3A perspective view of the receiver 300.

[0092] It should be understood that Figure 3A and 3B show one of a pair of receivers 300. In one embodiment, two receivers 300 are used in the probe contact assembly. The receiver 300 can be manufactured as a flat component using etching, stamping, e-forming, water jet cutting, or other suitable manufacturing processes. The material of the receiver 300 can be copper alloy or other suitable metal alloy. The receiver 300 can be gold-plated to enhance lubricity and conductivity.

[0093] In one embodiment, the receiver 300 includes a top 380, an aperture 320 having an upper stop 310 and a void 325, a body 330, two shoulders 350 (in the width direction), each having a shoulder stop 340, and a protrusion 360 having an end 370 (with a decreasing width in the Z direction). In one embodiment, the aperture 320 extends in the vertical direction (the height direction of the receiver 300) from the upper stop 310 to a position near the bottom of the shoulder 350. In the width direction (from one shoulder 350 to the other), the width of the bottom of the aperture 320 gradually decreases. In one embodiment, the size of the aperture 320 can be formed to receive a portion of the retainer 250, but is narrow enough such that the retainer 250 cannot pass through the aperture. The aperture 320 can have a uniform width along its length or can gradually widen towards the bottom to assist the movement of the retainer 250, but is still not wide enough to allow the retainer 250 to pass through.

[0094] In one embodiment, the aperture 320 is where the retainer 250 of the upper plunger 300 slides vertically (e.g., from the uncompressed state to the compressed state of the probe contact assembly, or vice versa). In the uncompressed state, the retainer 250 of the upper plunger 200 can rest on the upper stop 310 of the aperture 320. The body 330 preferably has a tapered outer surface, and the taper can be designed such that in the assembled state of the probe contact assembly, the taper can force the receivers 300 (the sides thereof) together to form a single contact point on the PCB in a narrowing gap such as a "V" shape or a substantially "V" shape (see, for example Figures 5A to 6C ), where the bottom ends of the receiver pair 300 are drawn together and / or are fully adjacent. The shoulder stops 340 can be configured to abut against the end coils of the spring 400. The shoulders (or flanges) 350 can be the widest part of the receiver 300 and can be used to ensure that the probe contact assembly can be held in the socket housing (e.g., see Figures 10A to 11B ). The end 370 of the protrusion 360 includes a contact surface that contacts the S&P terminals of the PCB.

[0095] In one embodiment, the thickness of the receiver 300 ( Figure 3AThe direction (into the paper surface) remains constant. The width or diameter (maximum width or diameter) of the shoulder 350 can be between the outer diameter and the inner diameter of the spring 400. The additional clearance area 325 can be configured to allow the retainer 250 not to drop to the lowest point on the receiver 300 (e.g., in the compressed state). The upper stop 310 is configured to act as an upper stop for the retainer 250 when the probe contact assembly is in the uncompressed state. The body 330 can be tapered from the upper stop 310 to the lower part of the body 330 by 10% or about 10% (the length of the tapered part is shown as "L" in the vertical direction). That is, along the "L" direction and within the length of the "L" part, the width of the body 330 gradually increases (tapers), and the width of the orifice 320 also increases (tapers). For the lower part of the orifice 320 (below the "L" part), the width of the orifice 320 can be reduced (e.g., to prevent the retainer 250 from moving downward toward the PCB). The circular bottom surface of the end 370 can be configured to make good contact with the pads of the PCB.

[0096] In one embodiment, the receiver 300 can be made of beryllium copper, copper alloy, nickel, or nickel alloy, etc. The receiver 300 can be etched, made via metal additive manufacturing, by electroforming, etc. In one embodiment, the receiver 300 can be gold-plated, etc. In one embodiment, the receiver 300 can have a height equal to 400 microns or about 400 microns. It should be understood that the bottom of the receiver 300 can be flat, round, etc. The receiver 300 can be manufactured at low cost by various methods (e.g., etching, electrical discharge machining, electroforming, stamping).

[0097] It should also be understood that the inside (e.g., in the orifice 320) and the outside (on the body 330) of the receiver 300 can be tapered (the length of the tapered part is shown as "L" in the vertical direction). The tapered part can allow for easy compression without jamming or binding, and can ensure that the receiver 300 gradually narrows so that a V-shaped or similar shape (e.g., from the uncompressed state to the compressed state, or vice versa) can be maintained. It should also be understood that the sides (in the thickness direction) of the upper part of the receiver 300 (e.g., above or near the upper stop 310) can slide along and on the inner shaft 240 (e.g., from the uncompressed state to the compressed state, or vice versa). The sides (in the thickness direction) of the lower part of the receiver 300 (e.g., above or near or at the end 370) can be in contact with each other.

[0098] Figure 4A is a side view of the spring 400 of a probe contact assembly for a test system according to an embodiment. Figure 4B is according to an embodiment Figure 4APerspective view of the spring 400. It should be understood that the biasing member 400 (such as an elastic member like a spring) can perform two functions: 1) It can provide compression or elasticity between the upper plunger 200 and the receiver(s) 300, and 2) It can hold the combination of the upper plunger 200 and the receiver(s) 300 together during normal operation so that they not only do not fall apart but also ensure electrical contact between the upper plunger 200 and the receiver(s) 300, thereby providing a circuit path between the DUT and the load board.

[0099] In one embodiment, the spring 400 (having a body 410 and two ends 412, 414) is a compression spring wound from elastic wire on a precision winding machine. The spring end coils (412, 414) can be "closed" such that there can be a small gap to no gap at the end coils (412, 414) to, for example, assist in assembly. It should be understood that there is a gap between the spring coils of the body 410. The wire material of the spring 400 has a constant wire diameter. The outer diameter of the spring 400 remains constant throughout the length of the spring 400. The number of turns of the spring 400 can vary according to electrical and mechanical requirements. The spring 400 can be made of a metal such as a stainless steel alloy. The spring 400 can be gold-plated to enhance the electrical performance of the probe contact assembly and provide lubricity when the probe contact assembly is compressed.

[0100] It should be understood that when compressed, the elastic spring 400 can create or induce z-axis (in the height direction) compliance in the socket. The inner diameter, outer diameter, and wire diameter of the spring 400 are each constant. The spacing between the coils of the spring 400 can allow for compression, and when the probe contact assembly 500 is in a compressed state, the coils of the spring 400 can still have spacing (i.e., the spring 400 can remain undeformed and last longer), except that there can be a small gap to no gap at the end coils (412, 414).

[0101] Figure 5A Front view of the probe contact assembly 500 for a test system according to one embodiment. Figure 5B is according to one embodiment Figure 5A Side view of the probe contact assembly 500. Figure 5C is according to one embodiment Figure 5A Perspective view of the probe contact assembly 500. Figure 5D is according to one embodiment Figure 5A Top view of the probe contact assembly 500. Figure 5E is according to one embodiment Figure 5A Bottom view of the probe contact assembly 500.

[0102] Figures 5A to 5EShows the probe contact assembly 500 in an uncompressed state. It should be understood that the uncompressed state may refer to the state where the probe contact assembly 500 is assembled and the spring 400 is in a free or uncompressed state. As Figure 5B shown, two receivers 300 are assembled from the bottom of the probe contact assembly 500, and the sides of the lower part of the receivers 300 contact each other in a "V" or substantially "V" shape. The spring 400 is captured between the shoulder stop 340 of the shoulder 230 of the upper plunger 200 and the shoulder 350 of the receiver 300. The retainer 250 of the upper plunger 200 abuts against the upper stop 310 of the orifice 320 of the receiver 300. Since the body 330 of the receiver 300 (extending from one shoulder stop 340 to the top 380 in the width direction and then to the other shoulder stop 340) is constrained into the inner diameter of the spring 400, the probe contact assembly 500 can be self - contained and will not fall apart.

[0103] It should be understood that compared with the prior art that relies on latches, the above - mentioned retaining system (i.e., the retainer 250 with the spring 400 that holds the components of the probe contact assembly 500 together) may be more robust. In contrast, for proper operation, the latch geometry must be precisely manufactured, and during the use of the probe or probe assembly, the latches on the components often wear, thus losing the holding force. The retaining system disclosed herein does not have the limitations of latches, and the receiver 300 can be held on the retainer 250 within a wide manufacturing tolerance, thereby reducing costs and complexity.

[0104] Figure 6A is a front view of the probe contact assembly 500 (in a compressed state) for a test system according to another embodiment. Figure 6B is according to another embodiment of Figure 6A a side view of the probe contact assembly 500. Figure 6C is according to another embodiment of Figure 6A a perspective view of the probe contact assembly 500. Figure 6D is according to another embodiment of Figure 6A a top view of the probe contact assembly 500. Figure 6E is according to another embodiment of Figure 6A a bottom view of the probe contact assembly 500.

[0105] Figures 6A to 6E Shows the probe contact assembly 500 in a compressed state. It should be understood that the compressed state may refer to the state where the probe contact assembly 500 is assembled and the spring 400 is in a fully compressed state. When the DUT (e.g., semiconductor device) is pushed down onto the tip (e.g., crown interface, etc.) of the probe contact assembly 500, the probe contact assembly 500 can be compressed. The combined spring force can ensure a good electrical contact interface with the DUT. AsFigure 6B As shown, in the compressed state, the retainer 250 of the upper plunger 200 moves to the bottom of the orifice 320 of the one or more receivers 300, and the "V" configuration of the receiver 300 is held in place. The "V" configuration can provide good sliding contact between the inner shaft of the upper plunger and the side of the upper part of the receiver 300. It should be understood that in the compressed state, due to the shapes of the orifice 320 and the retainer 250, there is a void area 325 between the retainer 250 and the bottom of the orifice 320.

[0106] It should be understood that during testing, for better RF performance, most of the current and resistance can come from the upper part and the receiver (which form the main path of the current). It should also be understood that there will be some current or a minimal amount of current passing through the spring.

[0107] Figure 7A is a top view of a probe contact assembly 500 for a test system according to an embodiment. Figure 7B is according to an embodiment Figure 7A of the probe contact assembly 500. Figure 7C is according to an embodiment Figure 7A of the probe contact assembly 500 taken along line A-A. Figure 7D is according to an embodiment Figure 7A of the probe contact assembly 500 taken along line B-B. Figures 7A to 7D shows the probe contact assembly 500 in an uncompressed state.

[0108] Figure 8A is a top view of a probe contact assembly 500 (in a compressed state) for a test system according to another embodiment. Figure 8B is according to another embodiment Figure 8A of the probe contact assembly 500. Figure 8C is according to another embodiment Figure 8A of the probe contact assembly 500 taken along line C-C. Figure 8D is according to another embodiment Figure 8A of the probe contact assembly 500 taken along line D-D. Figures 8A to 8D shows the probe contact assembly 500 in a compressed state. In the compressed state, the entire retainer 250 or a part of the retainer 250 extends outside the spring 400. The top of the retainer 250 is located at or near the shoulder stop 340.

[0109] Figure 9A is a front view of a probe contact assembly 500 for a test system according to an embodiment. Figure 9B is according to an embodiment Figure 9ACross-sectional view of the probe contact assembly 500 along line E-E. Figures 9A to 9B The probe contact assembly 500 in an uncompressed state is shown.

[0110] As Figure 9B shown, the inner shaft 240 of the upper plunger 200 separates the receivers 300 from each other at the upper part of the receiver 300. Four corners of the receiver 300 (each receiver 300 has two outer corners) contact the inner surface of the spring 400. The geometries of the retainer 250 and the receiver 300 and the inner diameter of the spring 400 are configured such that if there is any outward (in the direction towards the outside of the spring 400) biasing force attempting to disassemble the probe contact assembly 500, the receiver 300 can enter the spring 400 and be restricted. It should be understood that there is no press fit between the receiver 300 and the spring 400 so that the receiver 300 can slide along the length of the inner shaft 240.

[0111] Figure 10A is a cross-sectional perspective view of a plurality of probe contact assemblies 500 received in a socket housing 600 according to an embodiment. Figure 10B is Figure 10A An enlarged view of part F1, showing a probe contact assembly 500 received in a contact cavity (e.g., counterbore, countersink, etc.) of the socket housing 600 according to an embodiment. Figures 10A to 10B The probe contact assembly 500 in an uncompressed state is shown.

[0112] Figure 11A is a cross-sectional perspective view of a plurality of probe contact assemblies 500 (in a compressed state) received in a socket housing 600 according to an embodiment. Figure 11B is Figure 11A An enlarged view of part F2, showing a probe contact assembly 500 received in a contact cavity (e.g., counterbore, countersink, etc.) of the socket housing 600 according to an embodiment. Figures 11A to 11B The probe contact assembly 500 in a compressed state is shown.

[0113] As Figures 10A to 11B shown, the socket 150 (see Figures 1A to 1D) includes a housing 600. The housing 600 includes a housing body 650 having a plurality of cavities or holes (e.g., counterbores, countersinks, etc.) 680, each cavity being configured to receive a probe contact assembly 500. In one embodiment, the housing 600 can be made of a non-conductive material such as plastic, ceramic, etc. A thin retainer plate 640 can hold the probe contact assembly 500 in place on the bottom of the probe contact assembly 500. The retainer plate 640 can be a flat plate with simple through holes 660 to reduce the overall complexity of the socket 150 (including the housing 600 and the probe contact assembly 500), or it can be a countersunk plate. In one embodiment, the thickness of the retainer plate 640 can be 0.05 mm or about 0.05 mm. The retainer plate 640 can be mounted or fixed to the housing body 650 with screws, tape, or other means. The cavity or hole 680 includes a first cavity (e.g., countersink, etc.) 630, an upper stop 610, and a second cavity 620.

[0114] As Figures 10A to 10B shown, each probe contact assembly 500 can be located in the housing cavity (cavity 680) in an uncompressed or free state. The shoulder 230 abuts against the upper stop 610. The upper stop 610 is configured to prevent or stop the shoulder 230 from moving upward towards the DUT 110. The bottom of the shoulder 350 of the receiver 300 abuts against the retainer plate 640. The retainer plate 640 is configured to prevent or stop the shoulder 350 from moving downward towards the PCB (load board). The upper portions of the DUT interface 210 and the DUT side shaft 220 are positioned outside or above the cavity 630. The lower portion of the DUT side shaft 220 is received inside the cavity 630. The shoulder 230 and the spring 400 are received inside the cavity 620. The protrusion 360 and its end 370 pass through the through hole 660 of the retainer plate 640, and a part of the protrusion 360 and / or its end 370 is located outside or below the through hole 660. In one embodiment, the diameter of the cavity 630 is smaller than the diameter of the cavity 620 and smaller than the diameter of the shoulder 230. The diameter of the through hole 660 is smaller than the diameter of the cavity 620 and smaller than the width of the shoulder 350, but larger than the width of the protrusion 360 and its end 370.

[0115] When the probe contact assembly 500 is in a compressed state, the socket 150 is mounted to the PCB (not shown), and the DUT 110 (e.g., one or more terminals 112 of the DUT 110) is compressing the probe contact assembly 500. As Figures 11A to 11BAs shown, the contact assembly 500 is fully compressed by the DUT 110. The DUT interface 210 is pushed downward to or near the top surface of the housing 600. The shoulder 230 is pushed away from the upper stop 610 and downward into the cavity 620. The spring 400 is compressed. The end 370 of the protrusion 360 is located on or near the bottom surface of the retainer plate 640. The shoulder 350 is pushed away from the retainer plate 640 and upward into the cavity 620. In one embodiment, the compression length of the probe contact assembly is 1 millimeter or approximately 1 millimeter.

[0116] It should be understood that the shape (e.g., circular shape, etc.) or diameter of the contact assembly 500 can match the shape (e.g., circular shape, etc.) or diameter of the cavity of the housing 600.

[0117] Figure 12A is a front view of the receiver 301 (in a flat state during manufacturing) of a probe contact assembly for a test system according to another embodiment. Figure 12B is according to another embodiment Figure 12A perspective view of the receiver 301 (in a folded state).

[0118] It should be understood that the receiver 301 can be a single integral piece. That is, the receiver 301 can replace the two separate receivers 300 with a single part that is made to be a bonded piece (e.g., bonded at or near the location of the end 370 of the protrusion 360), and then folded to form a "V" - shaped assembly (see Figure 12B ). Then, the folded receiver 301 can be snapped onto the upper plunger 200. It should also be understood that a probe contact assembly with a single - piece receiver 301 can function in the same manner as the embodiment with two separate receivers 300.

[0119] Figure 13A is a perspective view of a probe contact assembly 501 according to one embodiment. Figure 13B is a perspective view of the probe contact assembly 501 in a compressed state according to another embodiment. The probe contact assembly 501 includes an upper plunger 200, a spring 400, and a receiver 301. Figure 13A Shows the probe contact assembly 501 in an uncompressed state. Figure 13B Shows the probe contact assembly 501 in a compressed state.

[0120] Figure 14A is a front view of the receiver 302 (in a flat state during manufacturing) of a probe contact assembly for a test system according to yet another embodiment. Figure 14B is according to yet another embodiment Figure 14A perspective view of the receiver 302 (in a folded state).

[0121] It should be understood that the receiver 302 can be a single integral piece. That is, the receiver 302 can replace the two separate receivers 300 with a single component that is made to be joined (e.g., joined at or near the side of the shoulder 350), and then laterally folded to form a "V" shaped assembly. Then, the folded receiver 302 can be snapped onto the upper plunger 200. It should also be understood that a probe contact assembly with a single integral receiver 302 can function the same as an embodiment with two separate receivers 300.

[0122] Figure 15A is a perspective view of a probe contact assembly 502 according to one embodiment. Figure 15B is a perspective view of a probe contact assembly 502 in a compressed state according to another embodiment. The probe contact assembly 502 includes an upper plunger 200, a spring 400, and a receiver 302. Figure 15A shows the probe contact assembly 502 in an uncompressed state. Figure 15B shows the probe contact assembly 502 in a compressed state.

[0123] Figure 16A is a front view of a receiver 303 of a probe contact assembly for a test system according to yet another embodiment. Figure 16B is according to yet another embodiment Figure 16A of the receiver 303. The receiver 303 is the same as the receiver 300 except that the receiver 303 includes a clearance 390 at the top 380 to allow for the manufacturing process. The clearance 390 extends from the orifice 320 to the outer top surface of the plunger 303.

[0124] Figure 17A is a front view of a probe contact assembly 503 according to one embodiment. Figure 17B is according to one embodiment Figure 17A of the probe contact assembly 503 in a side view. Figure 17C is according to one embodiment Figure 17A of the probe contact assembly 503 in a perspective view. Figure 17D is a front view of a probe contact assembly 503 in a compressed state according to another embodiment. Figure 17E is according to another embodiment Figure 17D of the probe contact assembly 503 in a side view. Figure 17F is according to another embodiment Figure 17D of the probe contact assembly 503 in a perspective view. The probe contact assembly 503 includes an upper plunger 200, a spring 400, and a pair of receivers 303.

[0125] The description of the invention set forth herein and its applications are illustrative and not intended to limit the scope of the invention. Variations and modifications of the embodiments disclosed herein are possible, and those of ordinary skill in the art will understand the actual alternatives and equivalents of the various components of the embodiments after studying this patent document. These and other variations and modifications can be made to the embodiments disclosed herein without departing from the scope and spirit of the invention.

[0126] Aspect

[0127] Note that any of the following aspects can be combined with each other.

[0128] Aspect 1. A compliant probe contact assembly for a test system for testing integrated circuit devices, the contact assembly comprising: an upper plunger including a first shoulder separating an upper shaft from a lower shaft and a retainer adjacent an end of the lower shaft; a first receiver and a second receiver configured to engage with the upper plunger, each of the first receiver and the second receiver including a second shoulder having a shoulder stop; and a biasing member, wherein when the contact assembly is assembled, the biasing member is captured between a bottom of the first shoulder and the shoulder stops of the first receiver and the second receiver, the upper plunger separates sides of an upper portion of the first receiver and sides of an upper portion of the second receiver, and sides of a lower portion of the first receiver and sides of a lower portion of the second receiver are in contact with each other.

[0129] Aspect 2. The contact assembly according to aspect 1, wherein the retainer, the lower shaft, and upper portions of the first receiver and the second receiver are constrained within an internal space of the biasing member.

[0130] Aspect 3. The contact assembly according to aspect 1 or aspect 2, wherein when the contact assembly is assembled, the first receiver and the second receiver form a substantially V shape.

[0131] Aspect 4. The contact assembly according to any one of aspects 1 to 3, wherein when the contact assembly is assembled, the contact assembly has an uncompressed state and a compressed state, and when the contact assembly is in the uncompressed state, the retainer abuts against an upper stop of an orifice of the first receiver and an upper stop of an orifice of the second receiver.

[0132] Aspect 5. The contact assembly according to aspect 4, wherein when the contact assembly is in the compressed state, the retainer is close to bottoms of the orifices of the first receiver and the second receiver, and a gap region is formed between the retainer and the bottoms of the orifices.

[0133] Aspect 6. The contact assembly according to any one of Aspects 1 to 5, wherein the first receiver and the second receiver are separate components.

[0134] Aspect 7. The contact assembly according to any one of Aspects 1 to 6, wherein the first receiver and the second receiver are joined together and form a single integral component.

[0135] Aspect 8. The contact assembly according to Aspect 7, wherein the first receiver and the second receiver are joined at the bottom end of the first receiver and the bottom end of the second receiver.

[0136] Aspect 9. The contact assembly according to Aspect 7, wherein the first receiver and the second receiver are joined at the second shoulder of the first receiver and the second shoulder of the second receiver.

[0137] Aspect 10. The contact assembly according to any one of Aspects 1 to 9, wherein each of the first receiver and the second receiver includes a gap at the top of the first receiver and the top of the second receiver.

[0138] Aspect 11. A test system for testing an integrated circuit device, the test system comprising: a device under test (DUT); a load board; and a compliant probe contact assembly, the compliant probe contact assembly comprising: an upper plunger including a first shoulder separating an upper shaft from a lower shaft; and a retainer adjacent an end of the lower shaft; a first receiver and a second receiver configured to engage with the upper plunger, each of the first receiver and the second receiver including a second shoulder having a shoulder stop; and a biasing member, wherein when the contact assembly is assembled, the biasing member is captured between the bottom of the first shoulder and the shoulder stops of the first receiver and the second receiver, the upper plunger separates the sides of the upper portions of the first receiver and the second receiver, and the sides of the lower portions of the first receiver and the second receiver are in contact with each other, wherein the upper plunger includes a DUT interface configured to engage with the DUT, and the ends of the first receiver and the second receiver are configured to engage with the load board.

[0139] Aspect 12. The test system according to Aspect 11, wherein the DUT is a device having a ball grid array package.

[0140] Aspect 13. The test system according to aspect 11 or aspect 12 further includes: a housing configured to accommodate the contact assembly.

[0141] Aspect 14. The test system according to aspect 13 further includes: a socket including the housing and the contact assembly, wherein the socket is configured to provide a path from the inputs and outputs of the DUT to the inputs and outputs of the load board, respectively.

[0142] Aspect 15. The test system according to aspect 13, wherein the housing includes a hole configured to accommodate the contact assembly, the hole including an upper stop between a first cavity and a second cavity, the diameter of the second cavity being greater than the diameter of the first cavity.

[0143] Aspect 16. The test system according to aspect 15, wherein the upper stop of the hole is configured to prevent the first shoulder from moving upward toward the DUT.

[0144] Aspect 17. The test system according to aspect 15 further includes: a retainer plate disposed at the bottom of the housing.

[0145] Aspect 18. The test system according to aspect 17, wherein the retainer plate includes a through hole configured to allow the bottom ends of the first receiver and the second receiver to pass through.

[0146] Aspect 19. The test system according to aspect 18, wherein the diameter of the through hole is smaller than the diameter of the second cavity of the housing.

[0147] Aspect 20. A compliant probe contact assembly for a test system for testing an integrated circuit device, the contact assembly including: a plunger including a retainer adjacent an end of a lower shaft; a first receiver plate and a second receiver plate having a top and a bottom, each receiver plate having a longitudinal orifice sized to receive only a portion of the retainer, the width of the orifice being insufficient to allow the retainer to pass therethrough; and a biasing member, wherein the first receiver plate and the second receiver plate are aligned relative to each other such that the first receiver plate and the second receiver plate are gradually closer to each other at the bottom relative to the top; wherein when the contact assembly is assembled, the biasing member surrounds at least a portion of the plunger and receives the first receiver plate and the second receiver plate, thereby maintaining physical and electrical contact between the first receiver plate and the second receiver plate and the retainer when the plunger moves along the orifice of the first receiver plate and the orifice of the second receiver plate.

[0148] The terms used in this specification are intended to describe particular embodiments and are not intended to be limiting. The terms "a", "an", and "the" also include plural forms unless clearly stated otherwise. When used in this specification, the terms "comprising" and / or "including" specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, and / or components.

[0149] Regarding the foregoing description, it should be understood that changes may be made in details, particularly in the construction materials used and in the shape, size, and arrangement of the components, without departing from the scope of the present disclosure. This specification and the described embodiments are merely exemplary, and the true scope and spirit of the present disclosure are indicated by the appended claims.

Claims

1. A compliant probe contact assembly for a test system for testing an integrated circuit device, characterized in that: The contact assembly includes: an upper plunger including a first shoulder separating an upper shaft from a lower shaft and a retainer adjacent an end of the lower shaft, the upper shaft having a diameter greater than a diameter of the lower shaft; first and second receivers configured to engage the upper plunger, each of the first and second receivers including a second shoulder having a shoulder stop; and Biasing member, wherein, when the contact assembly is assembled, the biasing member is captured between the bottom of the first shoulder and the shoulder stop of the first receiver and the shoulder stop of the second receiver, the upper plunger separates the side of the upper portion of the first receiver and the side of the upper portion of the second receiver, and the side of the lower portion of the first receiver and the side of the lower portion of the second receiver contact each other.

2. The compliant probe contact assembly according to claim 1, characterized in that: The retainer, the lower shaft, and the upper portions of the first and second receivers are constrained into an interior space of the biasing member.

3. The compliant probe contact assembly according to claim 1, characterized in that: When the contact assembly is assembled, the first receiver and the second receiver form a gradually narrowing gap.

4. The compliant probe contact assembly according to claim 1, characterized in that: When the contact assembly is assembled, the contact assembly has an uncompressed state and a compressed state, When the contact assembly is in the uncompressed state, the retainer abuts against an upper stop of the aperture of the first receiver and an upper stop of the aperture of the second receiver.

5. The compliant probe contact assembly according to claim 4, characterized in that: When the contact assembly is in a compressed state, the retainer is proximate to a bottom of the aperture of the first receiver and a bottom of the aperture of the second receiver, and a void area is formed between the retainer and the bottom of the aperture.

6. The compliant probe contact assembly according to claim 1, characterized in that: The first receiver and the second receiver are separate components.

7. The compliant probe contact assembly according to claim 1, characterized in that: The first receiver and the second receiver are joined together and form a single integral component.

8. The compliant probe contact assembly according to claim 7, characterized in that: The first receiver and the second receiver are joined at a bottom end of the first receiver and a bottom end of the second receiver.

9. The compliant probe contact assembly according to claim 7, characterized in that: The first receiver and the second receiver are joined at a second shoulder of the first receiver and a second shoulder of the second receiver.

10. The compliant probe contact assembly according to claim 1, wherein: The first receiver includes a gap at a top of the first receiver, and the second receiver includes a gap at a top of the second receiver.

11. A test system for testing an integrated circuit device, characterized in that: The test system comprises: Device under test (DUT); load board; and A compliant probe contact assembly, the compliant probe contact assembly comprising: an upper plunger including a first shoulder separating an upper shaft from a lower shaft and a retainer adjacent an end of the lower shaft, the upper shaft having a diameter greater than a diameter of the lower shaft; a first receiver and a second receiver configured to engage the upper plunger, each of the first receiver and the second receiver including a second shoulder having a shoulder stop; and Biasing member, wherein, when the contact assembly is assembled, the biasing member is captured between the bottom of the first shoulder and the shoulder stops of the first receiver and the shoulder stops of the second receiver, the upper plunger separates the side of the upper portion of the first receiver and the side of the upper portion of the second receiver, and the side of the lower portion of the first receiver and the side of the lower portion of the second receiver contact each other, The upper plunger includes a DUT interface configured to engage with the DUT, and an end of the first receiver and an end of the second receiver are configured to engage with the load board.

12. The test system according to claim 11, characterized in that: The DUT is a device having a ball grid array package.

13. The test system according to claim 11, characterized in that: Also includes: A housing is configured to accommodate the contact assembly.

14. The test system according to claim 13, characterized in that: Also includes: A socket, comprising the housing and the contact assembly, Wherein, the socket is configured to provide a path from an input and an output of the DUT to an input and an output of the load board, respectively.

15. The test system according to claim 13, characterized in that: The housing includes a bore configured to receive the contact assembly, the bore including an upper stop between a first cavity and a second cavity, the second cavity having a diameter greater than a diameter of the first cavity.

16. The test system according to claim 15, characterized in that: The upper stop of the hole is configured to prevent the first shoulder from moving upward toward the DUT.

17. The test system according to claim 15, characterized in that: Also includes: A retainer plate is disposed at a bottom of the housing.

18. The test system according to claim 17, characterized in that: The holder plate includes a through hole configured to allow bottom ends of the first receiver and the second receiver to pass therethrough.

19. The test system according to claim 18, characterized in that: A diameter of the through hole is smaller than a diameter of the second cavity of the housing.

20. A compliant probe contact assembly for a test system for testing an integrated circuit device, characterized in that: The contact assembly comprises: a plunger including a retainer adjacent an end of the lower shaft; first and second receiver plates having a top and a bottom, each receiver plate having a longitudinal aperture sized to receive only a portion of the retainer, the apertures being insufficiently wide to allow the retainer to pass through the apertures; and a biasing member having an inner diameter greater than a diameter of the lower shaft; wherein the first receiver plate and the second receiver plate are aligned relative to each other such that the first receiver plate and the second receiver plate are progressively closer to each other at the bottom than at the top; Wherein, when the contact assembly is assembled, the biasing member surrounds at least a portion of the plunger and receives the first receiver plate and the second receiver plate, thereby maintaining the first receiver plate and the second receiver plate and the retainer in physical and electrical contact as the plunger moves along the orifice of the first receiver plate and the orifice of the second receiver plate.

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