TWI503553B - Improved electrically conductive kelvin contacts for microcircuit tester - Google Patents

Improved electrically conductive kelvin contacts for microcircuit tester Download PDF

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Publication number
TWI503553B
TWI503553B TW100137922A TW100137922A TWI503553B TW I503553 B TWI503553 B TW I503553B TW 100137922 A TW100137922 A TW 100137922A TW 100137922 A TW100137922 A TW 100137922A TW I503553 B TWI503553 B TW I503553B
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Taiwan
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contact
force
contacts
sensing
applying
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TW100137922A
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Chinese (zh)
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TW201317582A (en
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Joel N Erdman
Jeffrey C Sherry
Gary W Michalko
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Johnstech Int Corp
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Description

Conductive Kelvin contact for microcircuit testers Field of invention

The present invention is directed to an apparatus for testing a microcircuit.

Background of the invention

As microcircuits continue to evolve smaller and more complex, test equipment for testing microcircuits is also evolving. Efforts are currently being made to improve microcircuit test equipment that leads to increased reliability, increased throughput and/or reduced overhead.

The cost of placing a defective microcircuit on a board is relatively high. Installation typically involves soldering the microcircuit to the board. Once placed on the board, removing the microcircuit becomes a problem because the second melt of the solder will destroy the board. Therefore, if the microcircuit is defective, the board itself may be destroyed, which means that all the value attached to the board at this time has been lost. For all of these reasons, the microcircuit is typically tested before it is mounted on the board.

Each microcircuit must be tested to identify all defective devices, but not a good device can be mistakenly identified as defective. Any type of error that occurs frequently can greatly increase the overall cost of the board manufacturing process and may increase the cost of retesting for devices that are incorrectly identified as defective.

The microcircuit test equipment itself is very complicated. First, the test equipment must perform precise and low resistance non-destructive temporary electrical contact with each closely spaced microcircuit contact. Due to the small size of the microcircuit contacts and the spacing between them, even small errors in making contact will result in incorrect connections. Connecting to a misaligned or otherwise incorrect microcircuit will cause the test equipment to identify the device under test (DUT) as defective, although the cause of the error is a flaw between the test equipment and the DUT. Electrical connection, not a defect in the DUT itself.

Another problem in microcircuit test equipment has emerged in automated testing. Test equipment can test 100 devices per minute or even more. The large number of tests resulted in wear on the tester contacts that were electrically connected to the microcircuit terminals during the test. This wear can cause conductive debris to fall off the tester contacts and the DUT terminals, which can contaminate the test equipment as well as the DUT itself.

The debris will eventually cause the electrical connections during the test to deteriorate and result in an erroneous indication that the DUT is defective. Debris sticking to the microcircuit may cause the kit to malfunction unless the debris is removed from the microcircuit. Removing debris again increases the cost and introduces another source of defects in the microcircuit itself.

There are also other considerations. Good and inexpensive tester contacts are advantageous. It is also desirable to minimize the time required to replace the tester contacts because test equipment is relatively expensive. If the test equipment is taken offline for extended periods of normal maintenance, the cost of testing a single microcircuit will increase.

Currently used test equipment has an array of tester contacts that are analogous to the pattern of microcircuit terminal arrays. The array of tester contacts is supported in a structure that precisely maintains the contacts aligned with respect to each other. The microcircuit itself is aligned with the test contact by an alignment plate or plate. Many times, the alignment plate is separated from the outer casing of the wrap contact because the alignment plate is subject to wear and needs to be replaced frequently. The test housing and alignment plate are placed on a load board having electrically conductive pads that are electrically connected to the test contacts. The load board pad is connected to a circuit path that carries signals and power between the test equipment electronics and the test contacts.

For electrical testing, it is desirable to form a temporary electrical connection between each terminal on the device under test and a corresponding electrical pad on the load board. In general, it is impractical to solder and remove each of the electrical terminals on the microcircuit that is contacted by the corresponding electrical probes on the test bench. Instead of soldering and removing each of the terminals, the tester can employ a series of conductive contacts that are arranged in a pattern that corresponds to the terminals on the device under test and the electrical pads on the load board. When the force is applied to contact the device under test with the tester, the contacts complete the circuit between the respective device contacts to be tested and the corresponding load pad pads. After the test, when the device under test is released, the terminal is separated from the contact and the circuit is broken.

This application is directed to improvements in these contacts.

There is a type of test called the "Kelvin" test that measures the resistance between the two terminals on the device under test. Basically, the Kelvin test involves forcing a current to flow between two terminals, measuring the voltage difference between the two terminals, and using Ohm's law to reciprocate the resistance between the terminals, ie dividing the voltage by the current. Given. Each terminal on the device under test is electrically connected to two contacts on the load board and their associated pads. One of the two pads provides a known amount of current. The other pad (referred to as the "sensing" connection) is a high impedance connection that acts as a voltmeter that draws only a small amount of current. In other words, each terminal on the device under test that undergoes the Kelvin test is simultaneously electrically connected to two pads on the load board, one of which provides a known amount of current and the other of which measures the voltage and simultaneously Only a small amount of current is drawn. The Kelvin test is performed on each of the two terminals, so that the single resistance measurement uses two terminals and four contact pads on the load board.

In the present application, contacts that form a temporary electrical connection between the device under test and the load board can be used in several ways. In a "standard" test, each contact connects a particular terminal on the device under test to a particular pad on the load board, where the terminals are in one-to-one association with the pads. For these standard tests, each terminal corresponds exactly to one pad, and each pad corresponds exactly to one terminal. In the "Kelvin" test, there are two contacts that contact each of the terminals on the device under test, as described above. For these Kelvin tests, each terminal on the device under test corresponds to two pads on the load board, and each pad on the load board exactly corresponds to one terminal on the device under test. Although the test protocol can vary, the mechanical structure and use of the contacts are essentially the same regardless of the test protocol.

Many aspects of the test bench can be combined from old or existing test benches. For example, many mechanical infrastructures and circuits from existing test systems can be used that are compatible with the conductive pins disclosed herein. Such existing systems will be listed and summarized below.

Test contact system for testing integrated circuits with packages having an array of signal and power contacts, which was tested on August 30, 2007, for testing its packaged test contact system with an integrated circuit of signal and power contact arrays. An exemplary microcircuit tester is disclosed in US Patent Application Publication No. US 2007/0202714 A1, the entire disclosure of which is incorporated herein by reference.

For the '714 tester, a series of microcircuits were tested sequentially, with each microcircuit (or "device under test") attached to the test bench, electrically tested and subsequently removed from the test bench. The mechanical and electrical aspects of such test stands are typically automated so that the throughput of the test stand can be kept as high as possible.

In '714, the test contact element for temporary electrical contact with the microcircuit terminal includes at least one toughness finger that protrudes from the insulating contact diaphragm as a cantilever. The finger has a conductive contact pad on its contact side for contacting the microcircuit terminal. The test contact element preferably has a plurality of fingers which may advantageously have a pie-like arrangement. In such an arrangement, each of the fingers is at least partially defined by two radially directed grooves in the diaphragm that each of the fingers and each of the plurality of fingers forming the test contact element One other finger is mechanically separated.

In '714, a plurality of test contact elements can form an array of test contact elements that include test contact elements that are disposed in a predetermined pattern. A plurality of connection paths are provided in substantial accordance with a predetermined pattern of test contact elements, each of which is aligned with one of the test contact elements. Preferably, the plurality of connecting passages are supported by the interface membrane in a predetermined pattern. Many passages can be embedded in the pie piece away from the device contact area to extend the useful life. The grooves separating the fingers can be plated to create an I-beam to prevent deformation of the fingers and also extend the useful life.

The connecting passage of '714 may be cup-shaped with an open end, wherein the open end of the cup-shaped passage is in contact with the aligned test contact elements. Fragments resulting from loading and unloading the DUT from the test equipment can fall through the test contact elements, with the cup-shaped passages receiving debris.

The contact and interface membrane of '714 can be used as part of a test vessel that includes a load plate. The load board has a plurality of connection pads that are substantially in accordance with a predetermined pattern of test contact elements. The load board supports the interface membrane, wherein each of the connection pads on the load board is substantially aligned with and in electrical contact with one of the connection paths.

In '714, the device uses a very thin conductive plating with retention properties that adhere to very thin, non-conductive insulators. The metal portion of the device provides multiple contact points or paths between the contact I/O and the load board. This can be accomplished with a plated through-hole shroud or with a plated through via, or with a raised surface having a first surface in contact with the second surface (ie, device I/O), which may be combined with a spring. Device I/O can be physically close to the load board to improve electrical performance.

One particular type of microcircuit that is often tested prior to installation has a package or housing that is commonly referred to as a ball grid array (BGA) terminal arrangement. A typical BGA package can be in the form of a flat rectangular block with a typical size range of 5mm to 40mm on one side and 1mm thick.

A typical microcircuit has a housing that encloses the actual circuit. The signal and power (S&P) terminals are on one of the two larger flat surfaces of the housing. Generally, the terminals occupy most of the area between the surface edge and any one or more spacers. It should be mentioned that in some cases the spacer may be a sealed wafer or ground pad.

Each of the terminals may include a smaller, approximately spherical solder ball that is firmly adhered to the leads that penetrate the surface from the internal circuitry and is therefore referred to as a "ball grid array." Each of the terminals and spacers protrude a small distance from the surface, wherein the terminals protrude from the surface a longer distance than the spacer. During assembly, all of the terminals are simultaneously melted and adhered to properly positioned wires previously formed on the board.

The terminals themselves can be fairly close to each other. The centerline spacing of some terminals can be as small as 0.25 mm, and even relatively wide spaced terminals can still be about 1.5 mm apart. The spacing between adjacent terminals is often referred to as "pitch."

In addition to the aforementioned factors, BGA microcircuit testing involves additional factors.

First, the tester should not damage the surface of the S&P terminal that is in contact with the board when making temporary contact with the ball terminal, as such damage may affect the reliability of the solder joint corresponding to the terminal.

Second, if the wires carrying the signal are kept short, the test process is more accurate. The ideal test contact setup has a short signal path.

Third, for environmental reasons, the solders commonly used in device terminals today are primarily tin. Tin-based solder alloys may produce an electrically conductive oxide film on the outer surface. Earlier solder alloys included large amounts of lead that did not form an oxide film. The test contacts must be able to penetrate the oxide film present.

BGA test contacts currently known and used in the art employ spring contacts composed of a plurality of parts including a spring, a body, and top and bottom plungers.

U.S. Patent Application Publication No. US 2003/0192181 A1, entitled "Method of making an electronic contact", issued on October 16, 2003, is shown to be equipped with irregularities arranged in a regular pattern. Microelectronic contacts, such as flexible sheet-like cantilever contacts. Each unevenness has sharp features on its tip that is remote from the surface of the contact. As the paired microelectronic component engages the contact, a wiping action causes the uneven sharp feature to scratch the mating component to provide an effective electrical interconnection, and optionally after activation of the bonding material Provides effective metallurgical bonding between the contact and the mating component.

U.S. Patent Application Publication No. US 2004/0201390 A1, entitled "Test interconnect for bumped semiconductor components and method of fabrication", published on October 14, 2004. The interconnect for testing the semiconductor component includes a substrate and contacts on the substrate for temporary electrical connection to the raised contacts on the component. Each of the contacts includes a recess and a lead pattern suspended above the recess that is configured to electrically engage the raised contact. The leads are adapted to move in the z-direction within the recess to allow for variations in the height and planarity of the raised contacts. Additionally, the leads may include a protrusion for penetrating the raised contacts, a non-adhesive outer layer for preventing adhesion to the raised contacts, and a curved shape that matches the topology of the raised contacts. The lead may be formed by forming a molded metal layer on a substrate, attaching a polymer substrate having a lead thereon to the substrate, or by etching the substrate to form a conductive beam.

U.S. Patent Application No. US 6,246,249 B1, entitled "Semiconductor inspection apparatus and inspection method using the apparatus", issued to Fukasawa et al. The device performs a test on the device under test with a ball-shaped connection terminal. The device includes a conductor layer formed on the support film. The conductor layer has a connecting portion. The ball joint terminal is connected to the connection portion. At least the shape of the connecting portion is changeable. The apparatus further includes a vibration absorbing member made of an elastically deformable insulating material to support at least the connecting portion. The test contact element of the invention for making temporary electrical contact with a microcircuit terminal includes at least one toughness finger projecting from the insulative contact diaphragm as a cantilever. The finger has a conductive contact pad on its contact side for contacting the microcircuit terminal.

A connector for a microelectronic device, U.S. Patent No. 5,812,378, to the name of "Microelectronic connector for an active bump leads" by Fjelstad et al., issued Sep. 22, 1998. A lamella-like body is provided that has a plurality of holes desirably disposed in a regular grid pattern. Each of the holes is provided with a pliable layered contact, such as a sheet metal ring, having a plurality of protrusions extending in the direction of the holes of the first major surface of the body. A terminal on the second surface of the connector body is electrically connected to the contact. The connector may be attached to a substrate such as a multilayer circuit board such that the terminals of the connector are electrically connected to leads within the substrate. A microelectronic component having raised leads thereon can be bonded to the connector and thus to the substrate by pushing the protruding leads into the holes of the connector to engage the protruding leads with the contacts. . The kit can be tested and, if found acceptable, the bumps can be permanently bonded to the contacts.

U.S. Patent Application Publication No. US 2001/0011907 A1, entitled "Test interconnect for bumped semiconductor components and method of fabrication", published on August 9, 2001, The interconnect used to test the semiconductor component includes a substrate and contacts on the substrate for temporary electrical contact with raised contacts on the component. Each of the contacts includes a recess and a support member suspended above the recess that is configured to electrically engage the raised contact. The support member is suspended above the recess on a spiral lead formed on a surface of the substrate. The helical lead allows the support member to move in the z-direction within the recess to allow for variations in the height and planarity of the raised contact. Furthermore, the spiral lead twists the support member relative to the raised contact to facilitate penetration of the oxide layer thereon. The spiral lead can be formed by attaching a polymer substrate having a lead thereon to the substrate or by forming a molded metal layer on the substrate. In an alternative embodiment of the contact, the support member is suspended above the surface of the substrate on the raised spring segment leads.

Consider an electronic wafer that is manufactured to be incorporated into a larger system. In use, the wafer electrically connects the device to a larger system through a series of contacts or terminals. For example, contacts on the electronic wafer can be inserted into corresponding sockets on the computer such that the computer circuitry can be electrically coupled to the wafer circuitry in a predetermined manner. An example of such a wafer may be a memory or processor for a computer, each of which may be inserted into a particular slot or socket that makes one or more electrical connections to the wafer.

It is highly desirable to test these wafers before shipment or before installing them in other systems. Such component level testing can illustrate problems in diagnosing manufacturing processes and can demonstrate improved system level throughput for systems incorporating the wafer. Therefore, complex test systems have been developed to ensure that the circuits in the wafer are executed as designed. The wafer is attached to the tester and tested as a "device under test" and then removed from the tester. In general, it is desirable to install, test, and remove as quickly as possible so that the throughput of the tester is as high as possible.

The test system accesses the wafer circuitry by the same contacts or terminals that would be used to connect the contacts or terminals of the wafer in the final application of the wafer. As a result, there are some general requirements for the test system that performs the test. In general, the tester should make electrical contact with the various contacts or terminals so that the contacts are not damaged and thus provide a reliable electrical connection with each contact.

Most of this type of tester uses mechanical contact between the wafer I/O contacts and the tester contacts, rather than soldering and de-soldering or some other attachment method. When the wafer is attached to the detector, each contact on the wafer will be in mechanical and electrical contact with a corresponding pad on the tester. After the test, the wafer was removed from the tester and the mechanical and electrical contacts were disconnected.

In general, it is highly desirable that the wafer and tester be subjected to as little damage as possible during attachment, testing, and removal. The pad layout on the tester can be designed to reduce or minimize wear or damage to the wafer contacts. For example, it is undesirable to scratch device I/O (leads, contacts, pads or solder balls), bend or deflect I/O, or perform any operation that may permanently alter or damage I/O in any way. Typically, the tester is designed to place the wafer in a final state that is as similar as possible to the initial state. In addition, it is desirable to avoid or reduce any permanent damage to the tester or tester pads so that the tester components can last longer before replacement.

Tester manufacturers currently spend a lot of effort on the pad layout. For example, the pads may include a spring loading mechanism that receives the wafer contacts with a specified resistance. In some applications, the pads may have an optional hard stop at the extreme end of the spring load force travel range. The goal of the pad layout is to establish a reliable electrical connection with the corresponding wafer contact, which can be as close as possible to the "closed" circuit when the wafer is attached, and as close as possible to the "off" when the wafer is removed. Open the circuit.

Because it is desirable to test these wafers as quickly as possible, or analogous to their practical application in larger systems, it may be desirable to drive and/or receive electrical signals from the contacts at very high frequencies. Current testers can be tested at frequencies up to 40 GHz or higher, and test frequencies are likely to increase with the advent of next-generation testers in the future.

For low-frequency testing, such as testing close to DC (0 Hz), electrical performance can be moved quite simply: you will want an infinitely high resistance when removing the wafer, and an infinitely low resistance when the wafer is attached. .

At higher frequencies, other electrical properties come into play, not just resistors. Impedance (or, in essence, resistance as a function of frequency) becomes a more appropriate metric for electrical performance at these higher frequencies. Impedance can include phase effects as well as amplitude effects, and can also contain and mathematically describe the effects of electrical resistance, capacitance, and inductance on the electrical path. In general, it is desirable that the contact resistance on the electrical path formed between the wafer I/O and the corresponding pad on the load card is sufficiently low that the contact resistance is low enough to maintain a target impedance of 50 ohms, so that the tester itself does not Significantly change the electrical performance of the wafer to be tested. Note that most test equipment is designed to have 50 ohm input and output impedance.

For contemporary wafers with many very small I/Os, the electrical and mechanical properties at the I/O interface of the analog device have become very helpful. Two-dimensional or three-dimensional finite element modeling has become a tool of choice for many designers. In some applications, once the basic geometry is selected for the tester pad construction, the electrical performance of the pad construction is analogized and then the specific size and shape are iteratively adjusted until the desired electrical performance is achieved. For these applications, once the electrical performance of the analogy reaches a certain threshold, the mechanical properties are determined almost in a post-remediation manner.

Summary of invention

One embodiment is a device for forming a plurality of temporary mechanical and electrical connections between a device under test having a plurality of terminals and a load plate having a plurality of contact pads, each of which is laterally arranged to be exactly one Corresponding to the terminal, the device comprises: a laterally directed electrically insulating outer casing adjacent to the contact pad on the load plate in a longitudinal direction; a plurality of electrically conductive force-applying contacts extending through the outer casing toward the device under test Upper longitudinal holes and may be squeezed/deflected through holes in the outer casing, each of the plurality of force applying contacts being laterally aligned to correspond to exactly one terminal; and a plurality of electrically conductive Sensing the contact, each of the plurality of sensing contacts being laterally arranged to correspond to exactly one force contact and exactly one terminal, each of the plurality of sensing contacts The measuring contact extends toward the device under test, approaching the corresponding force-applying contact. Each of the plurality of sensing contacts includes a fixed portion, a free portion extending away from the housing in an articulated manner, and a hinge portion connecting the fixed portion and the free portion. The hinge portion is laterally separated from the corresponding force applying contact. The free portion includes a forked portion at an end thereof that extends on opposite sides of the end of the respective force applying contact. The term "fixed portion" means that it is the point along which the bending of the contact member is limited so as to be blocked. The position of the fixed part or point relative to the tip determines the camber, everything else is the same.

A further embodiment is a device for forming a plurality of temporary mechanical and electrical connections between a device under test having a plurality of terminals and a load plate having a plurality of contact pads, each of the contact pads being laterally arranged to Corresponding to exactly one terminal, the device comprises: a laterally directed electrically insulating outer casing adjacent to the contact pad on the load plate in the longitudinal direction; a plurality of electrically conductive force-applying contacts extending toward the device under test A longitudinal bore in the outer casing and squeezable/deflectable through a hole in the outer casing, the squeezing comprising a lateral translation of a cross section of each of the urging contacts, each of the plurality of urging contacts The force-applying contacts are laterally arranged to correspond to exactly one of the terminals; and a plurality of electrically conductive sensing contacts, each of the plurality of sensing contacts being laterally aligned with exactly one force The contact member corresponds to exactly one terminal, and each of the plurality of sensing contacts is laterally surrounding the corresponding force applying contact and can slide horizontally/laterally along the outer casing Standard level / horizontal slide 8 corresponding to the example shown in FIG respective urging the contact member / transverse sectional lateral translation level.

Yet another embodiment is a device for forming a plurality of temporary mechanical and electrical connections between a device under test having a plurality of terminals and a load plate having a plurality of contact pads, each of which is laterally aligned and just Corresponding to a terminal, the device comprises: a laterally directed electrically insulating outer casing adjacent to the contact pad on the load plate in a longitudinal direction; a plurality of electrically conductive force-applying contacts extending through the device to be tested a longitudinal hole in the outer casing and squeezable/deflectable through a hole in the outer casing, each of the plurality of force applying contacts being laterally arranged to correspond to exactly one terminal; and a plurality of conductive And a sensing contact, each of the plurality of sensing contacts being laterally arranged to correspond to exactly one force contact and exactly one terminal. Each of the plurality of sensing contacts includes a pair of electrically conductive rods extending generally transversely along the outer casing. The pair of conductive rods are assembled in corresponding grooves on the electrically insulating outer casing. Each of the pair of conductive rods has an end that is bent out of the plane of the housing toward the device under test to strike an exposed I/O pad under the device under test. The two ends of each pair of sensing rods are directly adjacent to the respective force applying contacts and are located on opposite sides of the respective force applying contacts.

Simple illustration

Figure 1 is a side elevational view of a portion of test equipment for receiving a device under test (DUT) for standard electrical testing.

Figure 2 is a side view of the test equipment of Figure 1 electrically coupled to the DUT.

Figure 3 is a side elevational view of a portion of test equipment for receiving a device under test (DUT) for Kelvin testing.

Figure 4 is a side elevational view of the test equipment of Figure 3 electrically coupled to the DUT.

Figure 5 is a plan view of a first design of the force-applying and sensing contacts on the test equipment.

Figure 6 is a plan view of a second design of the force-applying contact and sensing contact on the test equipment.

Figure 7 is a plan view of a third design of the force-applying and sensing contacts on the test equipment.

Figure 8 is a plan view of a fourth design of the force-applying contact and sensing contact on the test equipment.

Figure 9 is a plan view of a fifth design of the force-applying contact and sensing contact on the test equipment.

Figure 10 is a plan view of a sixth design of the force-applying and sensing contacts on the test equipment.

Figure 11 is a plan view of a seventh design of the force applying contact and sensing contact on the test equipment.

Figure 12 is a side elevational view of two sets of terminals/contacts for the test equipment of Figures 3 and 4 electrically coupled to the DUT.

Figure 13 is a side cross-sectional view of the sample geometry of the sense (voltage) contact on its path from the terminal on the device under test to the contact pad on the load board.

Figure 14 is a side cross-sectional view of another sample geometry of the sensing (voltage) contact on its path from the terminal on the device under test to the contact pad on the load board.

Figure 15 is a side elevational view of a pair of sensing contacts having tips that are angled outwardly from a central force applying (current) contact.

Figure 16 is a top plan view of a pair of sensing contacts, at their ends, the pair of sensing contacts including laterally extending portions that extend toward each other.

Figure 17 is a top plan view of a pair of sensing contacts, at their ends, the pair of sensing contacts including laterally extending portions that extend toward each other.

Figure 18 is a top plan view of a single sensing contact, at the end of which the sensing contact includes a laterally extending portion that extends midway around the force applying contact.

Figure 19 is a top plan view of a single sensing contact, at the end of which the sensing contact includes a laterally extending portion that does not extend midway around the force applying contact.

Figure 20 is a side elevational view of a pair of sensing contacts having tips that are inclined toward one another and intersect each other above or beside the central force-applying contact.

Figure 21 is a top plan view of a pair of sensing contacts, at their ends, the pair of sensing contacts including laterally extending portions that extend upward beyond the plane of the paper.

Figure 22 is a perspective schematic view of an integrated circuit package with leads and its Kelvin contact system.

Figure 23 is an enlarged perspective view of the system of Figure 22 with a portion removed for clarity.

Fig. 24 is a view similar to Fig. 23, but viewed from the other side.

Figure 25 is a side elevational view of a system applied to a device with leads in a squeezed state.

Figure 26 is a view similar to Figure 25 except that the elastic portion is removed.

Fig. 27 is a view similar to Fig. 25 except that the extruded state and the sensing contact are designed to only collide with the front portion of the lead protruding from the device.

Figure 28 is a view similar to Figure 27, but viewed from the other side, and the solution has upwardly bent tines (instruments) to begin to contact the device more quickly, thereby providing greater Adaptability.

Fig. 29 is a schematic view showing both the unsqueezed state and the pressed state of the concept of connecting only the front portion of the device lead.

Fig. 30 is a schematic view similar to Fig. 29, showing the uncompressed state and the squeezed state of the double-pronged concept of sensing the tines across the force-applying contact.

Figure 31 is a perspective view showing the urging contact of the fork-shaped sensing lead across the reduced tip thickness.

Figure 32 is a perspective view similar to Figure 31 showing a single-sided sensing lead and a biasing contact with offset.

Figure 33 is a perspective view similar to Figure 29.

Figure 34 is a top perspective view similar to Figure 22 but for an alternate embodiment.

Figure 35 is a bottom perspective view similar to Figure 22 but for an alternate embodiment.

Figure 36 is a side plan view of the object of Figure 34.

Figure 37 is an exploded perspective view of Figure 34 with additional environment.

Figure 38 is a bottom perspective view of the object of Figure 37.

Figure 39 is an enlarged side plan view of an alternative embodiment.

Figure 40 is a top perspective view of an alternate embodiment.

Figure 41 is an enlarged perspective view of an alternative embodiment.

Figure 42 is an enlarged top perspective view of an alternate embodiment.

Figure 43 is an enlarged side plan view of an alternative embodiment.

detailed description

The following is a general summary of the present disclosure.

The terminals of the device under test are temporarily electrically connected to corresponding contact pads on the load board by a series of conductive contacts. These terminals can be pads, solder balls, wires (leads) or other contact points. Each terminal to be tested in Kelvin is connected to both a "force" contact and a "sense" contact, each of which is electrically coupled to a respective one of the contact pads on the load plate. The force-applying contact delivers a known amount of current to or from the terminal, sensing the voltage at the contact measurement terminal and drawing a negligible amount of current to or from the terminal. The sensing contact partially or completely surrounds the force-applying contact in a lateral direction so that it does not have to be elastic by itself, but it may also be elastic in itself. This helps to ensure alignment of the force-applying contacts by preventing lateral oscillations. In the first case, the sensing contact has a forked end with a prong extending to opposite sides of the force-applying contact. In the second case, the sensing contact completely surrounds the force-applying contact in the lateral direction and slides horizontally/laterally during the vertical pressing of the force-applying contact member to match the level translational component of the leveling section of the force-applying contact member. . In the third case, the sensing contact comprises two rods, the ends of which are located on opposite sides of the force-applying contact, and the two rods are parallel and extend laterally away from the force-applying contact. In these cases, the sensing contact extends in the horizontal direction along the partition or housing that supports the force-applying contact. These rods can be placed in corresponding grooves along the partition or on the outer casing.

The preceding paragraphs are merely an overview of the invention and should not be construed as limiting in any way. The test apparatus will be described in more detail below.

Figures 1 and 2 show a tester performing a conventional electrical test in which there is a one-to-one correspondence between the terminals on the device under test and the contact pads on the load board. In contrast, Figures 3 and 4 show a tester that performs a Kelvin test in which there are two contact pads on the load board that are connected to each terminal on the device under test. Although there are differences between traditional testing and Kelvin testing, tester components have a lot in common. Thus, it will first be described with respect to Figures 1 and 2. After describing the traditional tests, the components used in the Kelvin test are then described, as shown in Figures 3 and 4. At this point, the difference between the two situations is highlighted in the description.

Figure 1 is a side elevational view of a portion of test equipment for receiving a device under test (DUT) for conducting conventional electrical testing. The DUT 1 is placed on the tester 5, an electrical test is performed, and then the DUT 1 is removed from the tester 5. Any electrical connection is made by pressing the component into electrical contact with other components; in the DUT 1 test, no soldering or de-soldering is applied at any point.

The entire electrical test process can last only a fraction of a second, so that placing the device under test 1 quickly and accurately becomes very important to ensure efficient use of the test equipment. To achieve high throughput of the tester 5, it is usually necessary to grasp the device under test 1 using a robot. In most cases, the robotic system places the DUT 1 on the tester 5 prior to testing, and once the test is complete, the DUT 1 is removed. The grip and placement mechanism can use mechanical and optical sensors to monitor the position of the DUT 1 and a combination of translational and rotary actuators to align and position the DUT 1 on the test bench. Such automated mechanical systems are well established and have been used in many known electrical testers; these known robotic systems can also be used with any or all of the tester elements disclosed herein. Alternatively, the DUT 1 can be placed by hand or by a combination of hand-held and automated equipment.

Similarly, the electrical algorithms used to test each of the terminals on the DUT 1 are well established and have been applied to many known electronic testers. These known electrical algorithms can also be used with any or all of the tester elements disclosed herein.

The device under test 1 typically includes one or more devices and includes signal and power terminals that are coupled to the device. The device and the terminal may be located on one side of the device under test 1, or may be located on both sides of the device under test 1. For use in the tester 5, all terminals 2 should be accessible from one side of the device under test 1, although it should be understood that one or more components may be located on the other side of the device under test 1, or there may be other The components and/or terminals are located on the other side that cannot be tested by accessing terminal 2.

Each of the terminals 2 is formed as a small pad on the bottom side of the device, or may be a lead protruding from the body of the device. Prior to testing, the pads or leads 2 are attached to an electronic lead that is internally connected to other leads, to other electronic components, and/or to one or more of the devices in the device under test 1. The size and size of the pads or leads can be controlled fairly accurately, and the pad-to-pad or lead-to-lead size changes or positional variations typically do not pose significant difficulties. During the test, terminal 2 remains solid without melting or reflowing any solder 2.

The terminal 2 can be arranged in any suitable pattern on the surface of the device under test 1. In some cases, terminal 2 may be in the form of a generally square grid that is the starting point for the description of the lead portion describing the device under test 1, QFN, DFN, MLF or QFP. There may also be forms other than rectangular grids, including irregular spacing and geometry. It should be understood that the specific location of the terminals can be varied as desired, and the pads on the load board and the corresponding locations on the spacers or the contacts on the housing can be selected to match the position of the terminal 2 of the device under test. Generally, the spacing between adjacent terminals 2 is in the range of 0.25 mm to 1.5 mm, which is commonly referred to as "pitch."

When viewed from the side, as shown in Fig. 1, the device under test 1 appears as a row of terminals 2, which optionally includes gaps and irregular intervals. According to typical manufacturing processes, these terminals 2 are made generally planar or as flat as possible. In many cases, if there are wafers or other components on the device under test 1, the protruding height of the wafer will generally be smaller than the protruding height of the terminal 2 from the device under test 1.

The tester 5 of Fig. 1 includes a load board 3.

The load board 3 includes a load board substrate 6 and a circuit for electronically testing the device under test 1. Such circuitry may include drive electronics capable of generating one or more AC voltages having one or more particular frequencies and detection electronics capable of sensing the response of the device under test 1 to these drive voltages. Sensing can include detection of current and/or voltage at one or more frequencies. These drive and sense electronics are known in the industry, and any suitable electronic device from known testers can be used with the tester elements disclosed herein.

In general, it is highly desirable that the elements on the load board 3 be aligned with corresponding elements on the device under test 1 during installation. Typically, the 1 of the device under test and the load plate 3 are mechanically aligned with one or more positioning elements on the tester 5. The load plate 3 may comprise one or more mechanical positioning elements, such as reference or precisely positioned holes and/or edges, which ensure that the load plate 3 can be accurately placed on the tester 5. These positioning elements typically ensure lateral alignment (x, y) of the load plate and/or also ensure longitudinal alignment (z). These mechanical positioning elements are known in the industry, and any suitable electronic device from a known tester can be used with the tester elements disclosed herein. The mechanical positioning elements are not shown in Figure 1.

In general, load plate 3 may be a relatively complex and expensive component. In many cases, it is advantageous to introduce in the tester 5 an additional, relatively inexpensive component that protects the contact pads 4 of the load plate 3 from wear and damage. This additional component may be the interposer spacer 10. The inserter spacer 10 is also suitable for use The positioning element (not shown) is mechanically aligned with the load plate 3 and is present in the tester 5 above the load plate 3 facing the device under test 1.

The interposer spacer 10 includes a series of electrically conductive contacts 20 that extend longitudinally outwardly on both sides of the spacer 10. Each contact 20 can include a resilient element, such as a spring or elastomeric material, and can direct current from the device under test to/from the load board to the device under test with a sufficiently low resistance or impedance. Each of the contacts may be a separate conductive unit or alternatively may be formed as a combination of conductive elements.

In general, each contact 20 connects a contact pad 4 on the load board 3 to a terminal 2 on the device under test 1, although there may be such a test scheme: multiple contact pads 4 and separate One terminal 2 is connected, or a plurality of terminals 2 are connected to a single contact pad 4. For simplicity, it is assumed herein and in the drawings that a single contact 20 connects a single pad to a single terminal, although it should be understood that any of the tester elements disclosed herein can be used to contact multiple contacts. The pads are connected to a single terminal or a plurality of terminals are connected to a single contact pad. Typically, the interposer spacer 10 electrically connects the load plate contacts and the bottom contact surface of the test contact. Alternatively, it can be used to convert an existing load board pad configuration to a medium that is a test socket for connecting and testing the device under test.

Although the inserter septum 10 can be removed and replaced relatively easily as compared to removing and replacing the load plate 3, the inserter septum 10 is considered to be part of the tester 5 for this document. During operation, the tester 5 includes a load plate 3, an inserter spacer 10, and a mechanical structure (not shown) that mounts and holds them in the correct position. Each device under test 1 is placed against the tester 5, electrically tested, and removed from the tester 5.

A single interposer spacer 10 can test a large number of devices under test 1 before use, and typically thousands of tests or more can be continued before replacement is required. In general, it is desirable to replace the inserter separator 10 relatively quickly and simply, so that only a small amount of downtime is required to replace the diaphragm tester 5. In some cases, the speed at which the interposer separator 10 is replaced may even be more important than the actual cost of each separator 10, as the increase in tester execution time during operation can result in appropriate cost savings.

FIG. 1 shows the relationship between the tester 5 and the device under test 1. When each device 1 is tested, it is placed in a suitable robotic manipulator with sufficiently precise placement properties so that the particular terminal 2 on the device 1 can be on the corresponding contact 20 and load plate 3 on the interposer spacer 10. The corresponding contact pads 4 are placed accurately and reliably (in the x, y and z directions).

A robot manipulator (not shown) applies force to each device under test 1 to make contact with the tester 5. The magnitude of the force depends on the exact configuration of the test, including the number of terminals 2 to be tested, the force for each terminal, typical manufacturing and alignment tolerances, and the like. Generally, the force is applied by the robot of the tester (not shown) to act on the device under test 1. Generally, the force is generally longitudinal and is generally parallel to the surface normal of the load plate 3.

Figure 2 shows the tester and the device under test 1 in contact, at which point sufficient force is applied to the device under test 1 to engage the contacts 20 and the respective contacts on each of the terminals 2 on the load plate 3 An electrical connection 9 is formed between the pads 4. As mentioned above, there may alternatively be a test scheme in which a plurality of terminals 2 are connected to a single contact pad 4, or a plurality of contact pads 4 are connected to a single terminal 2, but for the sake of simplicity, in the drawing It is assumed that a single terminal 2 is uniquely connected to a single contact pad 4.

Figures 1 and 2 above show a conventional electrical test that essentially answers the question: "Is terminal A fully electrically connected to terminal B?" The current is driven from the load board to a particular terminal on the device under test, Flow inside the device under test to the other terminal and then return to the load board.

Unlike traditional electrical testing, the Kelvin test essentially answers the question: "What is the resistance between terminal A and terminal B?" As with conventional testing, current is driven from the load plate to the terminal, flowing internally to the other One terminal and then back to the load board. However, in the Kelvin test, each terminal simultaneously electrically contacts two contacts. One of the pair of contacts supplies a known amount of current (I), as is done in a conventional test, while the other of the pair of contacts measures the voltage (V) without taking a large amount Current. From a known amount of current (I) and voltage (V), Ohm's law (V = IR) can be used to determine the resistance R (= V / I) between two specific terminals on the load board.

A force or "current" contact can be considered a low resistance or low impedance contact, while a sense or "voltage" contact can be considered a high resistance or high impedance contact. Note that a typical voltmeter works in a manner similar to high resistance sensing or "voltage" contacts.

Figures 3 and 4 show the tester performing the Kelvin test. Many of the components are similar to those of the conventional tester shown in Figures 1 and 2, and are numbered accordingly.

Note that for each terminal 2, there is a pair of contact pads 4, one of which is for current and the other for voltage. For each terminal 2 and each pair of contact pads 4, there is also a pair of contacts 20, each of which electrically connects the contact pads 4 with the respective terminals 2. Note that the two contacts in each pair are typically electrically insulated from one another and form an electrical connection 9 between the terminals 2 and the contact pads 4. Figure 12 shows a full view of two pairs of terminals/contacts for the test equipment of Figures 3 and 4.

In the schematic views of Figs. 3 and 4, the contacts 20 are all drawn to be similar in shape and size, and are placed adjacent to each other such that the terminals are in contact with both contacts at the same time. Although this is sufficient from an electronic point of view, there are still many deficiencies in the mechanical aspect. For example, the terminals may be laterally offset with respect to the contacts such that the terminals can only contact one contact and not the other. Furthermore, separators with such a Kelvin test scheme may be mechanically more complex than comparable conventional test methods because the number of contacts is actually doubled while the side area used for the contacts remains the same. In general, so many contacts are placed in such a small size due to the small size of the components and the need for springs, elastomers or some other mechanical resistance generating device to produce z-axis compliance for each contact. The area is mechanically a challenge. As a result, there is a need to improve the mechanical arrangement of the electrical scheme shown in Figures 3 and 4. The remainder of this paper addresses this need and gives a variety of different mechanical layouts that are superior to the shoulder-to-shoulder designs of Figures 3 and 4.

A simple feature is that the main or separate dependence of the force (current) contact has resilience, i.e., the spring force or resistance that pushes back on the terminal when the device under test is forced to contact the tester. This reduces the mechanical complexity required to sense (voltage) contacts.

Moreover, in some cases, the sensing contacts may have less stringent electrical requirements than the force-applying contacts because the purpose of sensing the contacts is to measure the voltage without drawing a large amount of current. Such low current flow may allow the sensing contact to be thinner than the force-applying contact and may allow the sensing contact to be bent into a wide variety of shapes and orientations. Some of these shapes are acceptable for sensing contacts, but if they are used for more demanding electrical contact contacts, they may exhibit unacceptable high frequency performance.

Removing the resilience from the sensing contacts and relaxing the criteria for electrical performance may allow the sensing contacts to have a wide variety of orientations and shapes.

For example, one end of the sensing contact may be located adjacent to the top end of the force applying contact. The sensing contact can then extend generally laterally along the top surface of the inserter or housing (sometimes referred to as a partition), can be bent downward through the aperture in the housing, and can contact the load after passing through the housing Corresponding contact pads on the board.

The design 50 of Fig. 5 shows a portion of an exemplary housing 51 that is laterally aligned to correspond to the terminal 2 on the device under test 1 through an array of apertures 53 of the housing 51, passing upwardly (toward the device under test 1) Two exemplary force-applying (current) contacts projecting from the apertures 53, two exemplary sensing (voltage) contacts 54 extending laterally away from the top of the force-applying contact 52, and contact forces on the device under test 1 respectively Two exemplary terminals 2 of both the contact 52 and the sense contact 54. The leftmost exemplary terminal 2 corresponds to a state in which the device under test 1 is just in contact with the tester 5, and the rightmost exemplary terminal 2 corresponds to a state in which the device under test 1 is biased into contact with the tester 5.

On each of the force applying contacts 52, there is a recess that is removed from the top end that receives a portion of the distal end of the sensing contact 54. When the device under test 1 is forced into contact with the tester 5, each terminal 2 is in mechanical and electrical contact with both the respective force applying contact 52 and the respective sensing contact 54. The contact member 54 has a planar arm 54a, a projection 54b that preferably rises from the surface of the outer casing along a line that reaches the contact point 54c. The projection 54b can also be arcuate, concave or convex. Contact point 54c preferably has an acute intersection at its end. The acute angle helps to remove the oxide on terminal 2 during insertion.

For the case where little or no contact force is applied (the leftmost terminal 2 shown in Fig. 5), the force applying contact 52 protrudes upward by its own resilience. A portion of the distal end of the sensing contact 54 is also bent upward such that its tines 54a (in FIG. 6) and the plane of the portion 64 are at an angle of 20 to 30 degrees (ie, 20 degrees or 21, .. .,30 degrees). The tines 54a also taper inwardly toward the force applying contact 62, preferably forming a triangular tip (Fig. 6) or a rectangle (Fig. 5) along a straight line, but may also reach the tip along the arcuate line. The sensing contact 54 may have a fixed portion attached to or integrally formed with the outer casing 51, a hinge portion laterally separated from the force applying contact 52, and a free extension beyond the hinge portion toward the top end of the force applying contact 52 section.

The sensing contact 54 may be formed in multiple layers and may be mounted to the top surface of the outer casing 51 or mounted on a partition that rests on the outer casing 51. For example, the layer closest to the outer casing 51 can be a semi-rigid film-like layer that is electrically non-conductive. This layer can be made of polyimine, kapton, PEEK or any other suitable material. A conductive layer can be deposited on top of the film-like insulator and can be deposited in a strip shape that is not intersecting, with each strip corresponding to a particular terminal 2.

Such a layer structure of the sensing contact 54 can be used with any suitable configuration of the force-applying contact 52 because no components are added directly within the housing between any of the force-applying contacts 52. An example force-applying contact 52 that can be used is disclosed in U.S. Patent No. 5,749,738, the entire disclosure of which is incorporated herein by reference. Other suitable force applying contacts 52 can also be used.

Note that there is a certain benefit from the scratching of the terminal 2 from the sensing contact 54 for reducing the contact resistance due to oxide layer buildup. Because the hinge portion is relatively close to the current contact, the free portion is relatively short compared to the vertical deflection range of the current contact. As a result, there is a significant lateral component for the vertical compression of the sensing contact 54. In practice, this means that when the terminal 2 on the device under test 1 initially contacts the sensing contact 54, it makes contact at a specific position on the terminal 2. As the terminal 2 further deflects/squels the sensing contact 54, the sensing contact 54 slides in the horizontal direction, but does not slide over the terminal 2 toward the force-applying contact. This sliding is generally considered beneficial because it can penetrate any oxide layer that has accumulated on terminal 2.

The specific geometry of the contacts determines the exact amount of sliding. For a rigid free portion having a length L that ends its stroke with the angle A extending upward and is flush with the outer casing (angle 0), the level of the wiping stroke is L (1-cosA). Note that the vertical range of the stroke is L(sinA). In fact, if the free portion is too long, there will not be enough lateral travel to produce a significant scratch. Similarly, if the free portion is too short, there is a risk of damaging the free portion during bending due to bending or breaking the extension of the contact.

FIG. 6 shows another mechanical design 60 of the sensing (voltage) contact 64. Here, each of the sensing contacts 64 forms a fork shape having prongs that extend to opposite sides of the respective force-applying contacts 62. Sensing the prongs of the contacts 64 helps maintain the lateral alignment of the force-applying contacts 62 by preventing or reducing lateral oscillations during use. Due to the possible connections on either side of the force-applying contact 62, any misalignment of the device will result in contact with at least one side of the fork.

In this case, leaving the fork, the sensing contact 64 is a solid conductive member that is positioned over the test contact housing 61. The sensing contact 64 extends away from the force-applying contact 62 in the horizontal direction, and is bent downward through a hole in the outer casing 61 to be exposed from the outer casing 61 and contact the corresponding contact pad 4 on the load plate 3, such as the 13th and Figure 14 shows.

Each of the prongs on the fork includes an upwardly bent tip that is partially or completely tilted toward the device under test 1. When the device under test 1 is forced to come into contact with the tester 5, the terminal 2 is in contact with the tip end of the force applying contact 62 and the tip end of the prongs of the sensing contact 64 that is bent upward. The upwardly bent tip can be rigid (with a defined angle that does not change significantly during use) or can be spring-flexible. The upwardly bent tip also enables the sensing contact to avoid any protruding burrs on the device itself.

For rigid (non-bent) tips, some oxide is scratched from the terminals. The sharp point of the tip penetrates the oxide on the terminal. In the case of a flexible tip, there is a significant scratch in the manner previously described with reference to Figure 5. As the terminal 2 contacts the sensing contact tip, the sensing contact is deflected vertically such that the leveling portion of the sensing contact expands and contracts along the surface of the housing. This provides a contact force between the sensing contact and the terminal 2.

In the design 60 of Figure 6, the outer casing 61 can include a groove in the region surrounding or proximate to the force-applying contact 62 such that the sensing contact 64 can be slightly recessed into the outer casing. The contact 64 may include a planar portion 64a, a rising portion 64b, and a pair of tines 64c. The tines 64c can have sharp or point shaped contact engagement surfaces that will remove oxide from the terminals 2. The rising portion 64b may be linear (straight) or reach the tip 64c along a curved path. The tines 64c can have triangular teeth or other tapered or non-tapered structures as shown. Preferably, the tines 64b surround the 2, 3 or 4 sides of the contact 62 to help guide their alignment.

11 shows a design 110 in which the sensing contact 114 can have an elastomeric material "pad" 119 (or columnar in Figure 22) disposed between the prongs of the sensing contact 114 and the outer casing 111 Item 519) provides additional resilience. In addition to any existing resilience from the force-applying contact 112, this "pad" 119 can provide additional resilience to the contact.

Figure 7 shows another fork design in which the sensing contacts are formed as a plurality of layers, as previously done in accordance with Figure 5.

For the design 70 of FIG. 7, each of the sensing (voltage) contacts 74 has a portion 75 along the partition or housing 71 that may or may not be fixed and a free portion 76 that extends hingedly away from the housing 71. There is a hinge portion 77 that connects the fixed portion 75 with the free portion 76, which is separated from the corresponding force (current) contact 72 in the lateral direction. The free portion 76 has a forked portion 78 at its end that extends on opposite sides of the end of the respective force applying contact 72. Note that in Fig. 6, the free portion of the contact member 64 is longer than the free portion in Fig. 7, thereby allowing greater expansion and contraction and deflection. In other words, by moving the fixed point farther from the tip, the degree of expansion is increased, everything else is the same.

When the device under test 1 is biased toward the tester 5, the corresponding terminal 2 on the device under test 1 simultaneously presses the force-applying contact 72 through a corresponding hole 73 in the outer casing 71 and presses the sensing contact 74 toward the outer casing 71. The free part of 76.

As with the other designs shown herein, each of the terminals 2 on the device under test 1 makes direct electrical and mechanical contact with the top end of the respective force-applying contact 72. The terminal 2 on the device under test 1 also makes direct electrical and mechanical contact with the fork portion 78 of the corresponding sensing contact 74. The force-applying contacts 72 are not in electrical contact with the sensing contacts 74, although both of them mechanically and electrically contact the terminals 2 on the device under test 1.

Like the design shown in Fig. 5, the fixing portion 75 may be plated to the outer casing 71, or the fixing portion 75 may be freely suspended and facing the device under test 1. When the sensing contacts 74 are formed by such electroplating, each of the sensing contacts 74 is generally planar, including a conductive layer 79A facing the device under test 1, and includes an electrically insulating layer facing away from the device under test 1. 79B.

For the fork design of Figure 7, each of the sensing contacts 74 is generally planar, each fork portion 78 includes two parallel prongs, and each prong includes an extension of the sensing contact 74. The raised edge of the plane directly adjacent the corresponding force-applying contact 72. The raised or upwardly bent edge (which is bent downward in the underlying leaded configuration) may be formed by bending the rectangular portion of the prongs outwardly beyond its plane toward the device under test 1, which may be It is defined by the adjacent portion (usually planar) that senses the contact.

For the exemplary design 70 of FIG. 7, the respective terminals 2 on the device under test 1 are larger than the corresponding force-applying contacts 72 along a dimension perpendicular to the fork portion 78 and parallel to the outer casing 71. This helps to ensure that the device I/O or terminal 2 is in direct contact with both the force-applying contact 72 and the sensing contact 74, because even if there is a misalignment between the terminal 2 and the contact along the aforementioned dimensions In addition to the direct contact with the force-applying contact 72, the terminal 2 will also directly contact at least one prong of the forked portion 78 of the sensing contact 74.

The design of Figure 7 may allow for an advantageous scraping of oxide from the terminals, as previously described with reference to Figure 5.

In FIG. 8, as the force applying (current) contact 82 is squeezed over its entire range of compression, the sensing (voltage) contact 84 generally remains parallel to the outer casing 81 and may be along the outer casing 81. Slide or pan horizontally. In this design, the sensing contact 84 completely surrounds the force-applying contact 82 in the lateral direction so that if the force-applying contact 82 translates laterally, the sensing contact 84 can follow.

More specifically, the sensing contact 84 can translate along a transverse cross-section of the force-applying contact 82. Here are some clarifying examples. If the force-applying contacts 82 are completely cylindrical (ie, the cross-sections in each transverse plane are the same, wherein each cross-section does not have to be circular or elliptical), it is fully longitudinally oriented and completely longitudinal Upon being squeezed, the force-applying contact 82 does not translate laterally at all and the sensing contact 84 does not move. If the force applying contact 82 is cylindrical in shape, but is inclined with respect to the longitudinal direction and is pressed purely in the longitudinal direction, the cross section of the force applying contact 82 is translated, and the sensing contact 84 follows this Pan and also translate in landscape. If the force-applying contact member 82 is cylindrical in shape and has a rotational component when it is squeezed, as if it had an off-axis pivot point for its compression, it would have a transverse component when squeezed. The range is determined by the position of the pivot point. If the force-applying contact 82 is not truly cylindrical in shape, the sensing contact 84 can be moved along its cross-section by variations in shape, size, and/or orientation. For example, the force-applying contact 82 can have a particular edge that rises or falls laterally within the longitudinally compressed range, and for all or a portion of the compressed range, the sensing contact 84 can move with that particular edge.

This lateral translation of the sensing contact 84 can advantageously scrape off the oxide from the terminal 2 as previously described. For example, the sensing contact 84 can include a particular element that extends beyond the plane of the sensing contact 84, such as a prong, bracket, flange, or arm. This extension element 85 can act like a knife on the terminal 2 and can help scrape off any oxide layers present. It also acts as a guide rail that helps the contacts 82 remain aligned. In the illustration of Figure 8 In the exemplary design 80, the sensing contact 84 includes an arm that is bent upward toward the device under test 1 that is generally parallel with the adjacent face of the force-applying contact 82. Other appropriate points are also possible.

In most cases, the lateral translation of the cross-section of the force-applying contact is less than the size of the terminal 2 on the device under test 1 in the longitudinally compressed range, so that the force-applying contact 82 does not "leave" the device during use. I/O or terminal 2.

In the exemplary design 80 of FIG. 8, the sensing contact 84 extends completely transversely about the force-applying contact 82. Alternatively, there may be one or more gaps on the sensing contact 84 such that it only partially extends around the force-applying contact 82. For example, there may be a gap along one or more sides such that the sensing contact 84 can still "grab" the force-applying contact 82 for lateral translation. In some cases, the sensing contact 84 includes a portion or a complete fork-like structure surrounding the force-applying contact member 82, and perpendicular to the prongs, capable of engaging the force-applying contact member 82 in its compressed range relative to the two A partial or integral part of one or both sides of the side.

Figure 9 shows a contact design 90 similar to Figure 5, but with a relatively rigid rod 95 as the sensing (voltage) contact 94. The force (current) contact 92 has a recess that receives the end of the sensing contact rod 95 such that the terminal 2 on the device under test 1 can directly contact both the force-applying contact 92 and the sensing contact 94 independently. The optional electrically insulating coating on the sensing contact 94 and/or the force-applying contact 92 can help prevent shorting of the two contacts.

The rod 95 extends laterally away from the force-applying contact 92 along the side of the outer casing 91, and then passes through a hole in the outer casing 91, exits the outer casing 91 and contacts the corresponding contact pad on the load plate 3. 4. Note that any or all of the segments of the rod 95 may be straight, may have a periodic or irregular curvature and/or may be convoluted.

For the exemplary rod 95 shown in Figure 9, the rod 95 does not significantly scratch any oxide layer on the terminal.

The variant of the single rod of Figure 9 is a double rod, as shown in Figure 10.

In the design 100 of Fig. 10, the sensing (voltage) contact 104 includes two rods 105, one on each side of the force (current) contact 102, which are spaced away from the force contact along the top side of the outer casing 101. 102 extends laterally. The rods 105 can be joined together at a certain point to form a forked portion, similar to the forked structure shown previously. Alternatively, the rods 105 may remain separated as they extend across the outer casing 101. The rods 105 may be joined together by a single aperture in the outer casing 101 or separately through the outer casing 101 through respective apertures in the outer casing 101. Similar to many of the designs shown above, having two sensing contacts 104 on each side of the force-applying contact 102 increases redundancy in misalignment and also acts to place the force-applying contact 102 in the device The role of the automatic alignment tool on the center of the I/O or terminal 2. The rod 105 preferably has a straight (straight) portion, and then a curved or inclined portion that extends generally perpendicular to the straight portion.

In some cases, one or more of the rods 105 can be sunk into a corresponding groove or grooves in the outer casing 101. Such a groove can protect the rod 105 from damage. Moreover, these grooves may help attach the rod 105 to the outer casing 101 or help position the rod near the force-applying contact 102. Moreover, because the rod 105 can be electrically conductive, the outer casing 101 can be made of an electrical insulator and can help to electrically insulate each rod 105 from other rods 105 and other elements that are proximate to the rod 105. Moreover, the rods 105 can be coated with an electrically insulating material to prevent shorting with their respective force-applying contacts 102. A wide variety of materials can be used, including parylene, Teflon Peek Kapton and many more.

In some cases, each of the rods 105 has an end that is bent toward the plane of the outer casing 101 toward the device under test 1. This bent end can improve electrical contact with the terminal 2 on the device under test 1. Such a bent end can also position the electrical contact to the area near the bend, thereby leaving the bend, and each rod 105 is electrically insulated by the surrounding groove in which it is located.

In some cases, there is a pair of rods 105 associated with each force applying contact 102 that are placed on opposite sides of the force applying contact 102. The rod 105 has ends that are bent out of the plane of the outer casing 101 toward the device under test 1 as appropriate, which end spans the force-applying contact 102. The rod 105 then extends away from the force-applying contact 102 in the same direction along the outer casing 101, optionally in parallel grooves in the outer casing 101. These parallel grooves are optionally formed on separate positioning plates that are mounted to the outer casing 101. These ends can also point to a convergence point.

The respective terminals 2 on the device under test 1 are larger than the corresponding force-applying contacts 102 along a dimension perpendicular to the rod 105 and parallel to the outer casing 101. In general, when the device 1 is to be biased toward the outer casing 101, the corresponding terminal 2 on the device under test 1 simultaneously presses the force-applying contact 102 through the corresponding hole 103 in the outer casing 101 and contacts the corresponding sensing contact. The end of at least one of the conductive rods 105 of 104.

In some cases, the rod 105 is directly adjacent to the force-applying contact 102. It is advantageous that these rods can help hold the force-applying contact 102 in place during use and can help prevent oscillation.

In some cases, each rod 105 is an elongated column, optionally having a circular cross section. In other cases, each rod 105 can have a rectangular or square cross section. In some cases, each of the rods 105 may be formed separately from the outer casing 101 and then attached to the outer casing 101 or held in place by the alignment plates, which may be mounted to the outer casing. In other cases, each of the rods 105 may be integrally formed with the outer casing 101, such as by electroplating onto the surface of the outer casing 101 or into a groove on the outer casing 101.

Figure 13 is a side cross-sectional view of the design 130 showing the sample geometry of the sensing (voltage) contact 134 on its path from the terminal 2 on the device under test to the contact pad 4 on the load board 3, load The plate 3 has a plurality of small holes 142 of predetermined gaps.

The contact 134 extends laterally away from the terminal 2 along the surface of the outer casing 131, bent approximately 90 degrees (perpendicularly) through the aperture (portion 134b) in the outer casing 131, and the bend (portion 134c) is generally equal or preferably Slightly less than 90 degrees to be substantially parallel to the opposite face of the outer casing 131 after passing through the aperture 142. This bending, which is generally equal to or preferably less than 90 degrees, provides a certain biasing force to the load plate pad 4 to ensure a tight connection. When contacting the electrical contact pads 4 on the load board 3, a portion of the contacts 134 is disposed between the contact pads 4 and the outer casing 131 in the longitudinal direction. The aperture 142 is sized to be larger than the thickness of the contact portion therethrough. In a preferred embodiment, the aperture is rectangular or identical in shape to the contact therethrough, and the gap created between the contact portion 134b and the aperture wall should be sufficiently large to provide a rotational force (lever The force that can be applied from the pad 4 (or 2) to the contact 134c/d is transferred to the contact 134 on the pad 2 (or 4). Thus, the gap is wide enough to control the position of the contacts through the aperture, but still capable of transmitting such forces. Typically, a small hole having a width that is two or three times the thickness of the contact member may suffice.

Note that this cross-sectional view may be suitable for any of the sensing contacts previously shown to be planar (5th to 8th and 11th) or generally rod-shaped (Figs. 9 to 10). design. In those cases where the sensing contacts are self-supporting conductive substrates, such as wires or metal plates, the substrate can be bent in accordance with the geometry of Figure 13. In those cases where the sensing contacts are coated or plated onto an electrically insulating substrate, the insulating substrate can be bent in accordance with the geometry of Figure 13.

In the specific design 130 of Fig. 13, both ends of the contact member 134 are bent toward the terminal 2 on the device to be tested. There are many other alternatives to this geometry.

For example, Figure 14 shows a design 140 similar to design 130 in which contact 144 extends laterally away from terminal 2 along the surface of housing 141, bent 90 degrees (portion 134b) through aperture 142 in housing 141, and The bend (portion 134d) is approximately equal to or preferably slightly less than 90 degrees to be substantially parallel to the opposite side of the outer casing 141. This bending, which is generally equal to or preferably less than 90 degrees, provides a certain biasing force to the load plate pad 4 to ensure a tight connection. Unlike the design 130 of Figure 13, the design 140 of Figure 14 has opposite ends of the contact 144 extending in opposite directions, rather than both ends extending toward the terminal 2.

The design 140 of Figure 14 may be more advantageous than the design 130 of Figure 13. The advantages. For example, the contacts 144 themselves may be easier to manufacture and assemble. In some cases, such contacts 144 may be more easily bent than the corresponding contacts 134. In some cases, the geometry of Figure 14 can force the push pin into position (see the front turning force) to ensure the fit of the assembled part. In some cases, according to the geometry of Fig. 14, with respect to the holes in the outer casing 141, the torque generated by the terminals 2 or 4 can force the ends of the contacts 144 to contact the contact pads 4 on the load plate 3. Or 2 contacts, this would be desirable. This provides a bias to push the sensing contact towards the device under test and to make terminal 2 and sensing contact 144 easier to align.

The term "substantially parallel", as used previously, means that a 90 degree bend on contacts 134 and 144 that are directly adjacent to contact pads 4 may actually be less than 90 degrees. For example, the bend may be within the following ranges: 70-90 degrees, 75-90 degrees, 80-90 degrees, 85-90 degrees, 70-85 degrees, 75-90 degrees, 70-80 degrees, 75-85 Degree, 80-90 degrees, 70-75 degrees, 75-80 degrees, 80-85 degrees and/or 85-90 degrees. In some cases, the bend angle can be 80 degrees.

Note that any or all of the bends on the contacts 134 and 144 are optionally arcuate, rather than being acute as depicted in Figures 13 and 14. These arcs simplifies the manufacturing process of the contacts 134 and 144.

To this end, the sensing (voltage) contact has been generally shown as a rod or a set of prongs that extend upward toward the terminal 2 on the device under test 1. The end of the sensing contact optionally has a structure which in some cases may be illustrative of the scratching function previously described. Some examples are shown in Figures 15-20.

Figure 15 is a pair of force-applying (current) contacts 152 from the center outward A side view of the straddle sensing contact 154 of the tip 155 tilted at an angle. The tilt can be confined to the inside of the paper or alternatively extend or extend into the paper.

Figure 16 is a top plan view of a pair of sensing contacts 164, at their ends, the pair of sensing contacts 164 including laterally extending portions 166 that extend toward each other at a distal point. Sensing contacts 164, including their laterally extending portions 166, surround the central force-applying contacts 162.

Further, the laterally extending portion 166 protrudes beyond the paper surface toward the terminal 2 (not shown) on the device under test 1. In the diagram of Figure 16, terminal 2 will be between the paper and the viewer. The tip 167 of the laterally extending portion 166 will be closer to the viewer than the remainder of the contact 164. Note that the contacts 166, 167 extend generally perpendicularly away from the arms 165 such that they are parallel to one another and intersect the longitudinal axis 169 drawn through the contacts 162.

Figure 17 is a top plan view of a pair of sensing contacts 174, at their ends 175, the pair of sensing contacts 174 including laterally extending portions 176 that extend toward one another and are generally orthogonal to their arms 174. . Sensing contacts 174, including their laterally extending portions 176, do not surround the central force-applying contact 172, but intersect the longitudinal axis 169 of the passage 172. The central force-applying contact 172 can be imagined as being "outside" of the polygon formed by the pair of sensing contacts 174 and their laterally extending portions 176.

As with Figure 16, the laterally extending portion 176 extends beyond the paper surface, the terminal will be between the paper surface and the viewer, and the tip end 177 of the laterally extending portion 176 will be closer to the viewer than the remainder of the contact member 174.

21 is a top plan view of a pair of sensing contacts 214, at their ends 215, the pair of sensing contacts 214 include laterally extending portions 216 that extend toward one another. The sensing contacts 214, including their generally orthogonal laterally extending portions 216, surround the central force-applying contact 212, which passes through the gap between the contacts 214 and 215. The tip end 217 of the laterally extending portion 216 will be closer to the viewer than the remainder of the contact 214. Here, the laterally extending portions 216 are on opposite sides of the force-applying contact 212.

Figure 18 is a top plan view of a single sensing contact 184 that includes a laterally extending portion 186 that extends midway around the force-applying contact 182 at its end 185. As with Figures 16 and 17, the laterally extending portion 186 extends beyond the plane of the paper, the terminal will be between the paper and the viewer, and the tip 187 of the laterally extending portion 186 will be closer to the viewer than the remainder of the contact 184.

19 is a top plan view of a single sensing contact 194 that includes, at its end 195, a laterally extending portion 196 that does not extend midway around the force-applying contact 192. The laterally extending portion 196 is on the opposite side of the force-applying contact 192, as is the laterally extending portion 186 shown in FIG. As with Figures 16 through 18, the laterally extending portion 196 extends beyond the plane of the paper, the terminals will be between the paper and the viewer, and the tips 197 of the laterally extending portions 196 will be closer to the viewer than the remainder of the contacts 194.

Figure 20 is a side elevational view of a pair of sensing contacts 204 having tips 206 that are inclined toward one another and intersect each other above or beside the central force-applying contact 202. The tab or tip 206 can span the force-applying contact 202 after or before the force-applying contact 202. During contact with the terminal 2 on the device under test, the terminals push the tips 206 downwardly, urging them away from each other, causing a scrubbing action to penetrate the oxide layer on the terminals 2. The removal of oxides is an important achievement in this embodiment. The tilt can be confined to the inside of the paper or alternatively extend or extend into the paper. The cross arms may have a non-conductive coating on at least their back side to prevent shorting with the contact 202, or the contact 202 may just be formed so as not to contact the tip 206.

In general, the sensing contact can have a tip or tab that can extend out of the plane of the diaphragm toward the terminal on the device under test. When in contact with the terminal, the tab can be bent or telescoped independently of the motion or orientation of the sensing contact. This movement may be a bending motion, such as with a generally resilient material, and optionally a hinged structure at the proximal end of the tab that connects it to the remainder of the sensing contact. The tab optionally extends laterally across, across or around the force-applying contact. In some cases, there is a single sensing contact having a tip that extends laterally through the force-applied contact such that the force-applying contact is partially within the range of the sensing contact or partially within the sensing The range of contacts is "outside". In other cases, there are two sensing contacts that are generally parallel to each other, having tips that extend toward each other such that the force-applying contacts are partially within the range '' of the two sensing contacts' or portions The ground is "outside" the range of the two sensing contacts. Alternatively, the tips may extend laterally away from each other or may extend in any generally lateral direction except that the surface extends toward the terminal on the device under test. outer.

Although the force (current) contact is generally thicker than the sense (voltage) contact, and the previous description assumes this, it should be noted that the function of the two contacts is convertible and thus Thin contacts carry current and thicker contacts measure voltage. A preferred application for this would be to make the contacts in the housing trench thinner and to make the contacts above the housing thicker to handle more current.

In addition to ball grid arrays (BGAs) and other leadless packages with pads on the bottom side of the device, the structures of the present invention can also be applied to certain components in particular integrated circuits with leads or wires. It is called a lead contact package.

Figures 22-32 illustrate Kelvin contacts for a package with leads. In the sense that the components used in the BGA package or the package with pads on the bottom layer of the device are similar, they will have the same part number with an increase of 500. Thus, the contacts 2 in the BGA appear in the form of contacts 502 in a leaded package, and so on.

22, 22, 23 and 24 illustrate a lead device (DUT) 501 with a plurality of leads 502a, each having a contact 502. As in the case of the pad package, the force-applying contact 552 is typically in contact with the lead 502 at its central portion. Contact 552 is biased upwardly by element 519, which is similar to spacer 119 (Fig. 11), but is preferably cylindrical. (Note that the cylindrical shape can also be used in a pad or BGA configuration.) The second biasing block 519a is used to apply a downward force to the swing pin 600. The oscillating pin 600 is similar to the oscillating pin of the type shown in U.S. Patents 5,069,629 and 7,445,465, and such oscillating pins are incorporated herein by reference.

The contact extensions 544 are formed as shown in Fig. 22 such that they extend along a path to the load plate 503 where they make electrical contact. The extension provides an easier load board layout and helps to route the load board more easily. The sensing contact tip in Figure 22 has a double-pronged design. In this case, the tip end of the fork is flat in the horizontal direction, and there is no upward bending as in Fig. 6. This enables the terminal lead edge of the device under test to be scraped along the top surface of the fork and remove oxide.

The 25th, 26th, 27th, 28th, 29th, 30th, 31st and 32th drawings provide more detail on how the force-applying contact 552 and the sense contact 554 act on three different concepts. The force-applying contacts in Figures 27, 28 and 29 have a full width of the force-applying contact 600. The force-applying contacts of Figures 25, 26, 30, 31, and 32 have a reduced thickness tip 552 to prevent shorting to the sensing contact 554 and to provide a more blade-like edge (i.e., tip) It is narrower than the substrate to penetrate the oxide layer on the leads of the device under test. In Fig. 31, a flange 620 is shown which is the narrowed portion of the tip end 552. Figure 27 shows an alternative to Figure 26, in which the end of the sensing contact 554 is lifted out of the paper, similar to the concepts shown in Figures 20 and 21. First, the force-applying contact tip 552 preferably has a "tooth-like crown" with a ramp or recess 552a. The sensing contacts 554 of Figures 25, 26, 30 and 31 have fork ends terminated with two tines 554a and 554b, at their distal ends, having a plane away from the contact 554 at 20-30 degrees The angle (ie, 20, 21, ... or 30 degrees) is downward (the reverse of the pad package tines 554a) and the tines are tilted. Figure 32 shows an alternative to the twin-pronged tooth solution in which the force-applied contact tip 552 is offset to one side and the sensing contact 554 has only one tines. The gap between the force contact tip and the sense tines is centered on the centerline of the device lead to ensure adequate contact. The end of the contact 554 may be chamfered or rounded on its lower surface to provide a suitable clearance. The inner circumference 602 of the force-applying contact 600 is cut away (i.e., the front-to-back thickness is reduced) to ensure a gap with the sensing contact 554 as it moves.

In operation, contact 600 "swings" from the two positions shown in Figure 29 in response to contact with lead contact 502. Similarly, sensing contact 554 moves between the two positions shown. The movement of the various elements in Fig. 30 is the same as in Fig. 29, except that Fig. 30 shows the sensing contact with the downwardly inclined tines and the contact 600 with the reduced tip width. Note that the tines do not have to be tilted down to function.

Fig. 32 is a view showing a modification of the double-fork structure of Fig. 31. In this case, the sensing contact 554 has only a single tines 554a, which may or may not have a downwardly inclined portion (such as shown in FIG. 31). This allows the force-applying contact to have a large contact area as needed. In this design, the tip of the force-applied contact is offset and not concentrated on the width of the contact 600.

Figure 33 provides clarification in the following manner. In this embodiment, the sense contact 554 is not fork shaped. Furthermore, the sensing and force-applying contacts are preferably collinear, but preferably never in contact with each other. For the two contacts, they can be briefly contacted with each other upon insertion, and if so constructed, Figure 33 shows the lead contacts 502 in two positions. The final question is where to make the first contact. Sensing contact 554 first hits lead 502, and as 554 is stressed by its own resilience or alternatively against resilient element 519a, there will be a wiping action between the two contacts. As shown in the aforementioned contact, the sensing contact 554 is pressed downward until it is behind and adjacent to the oscillating force-applying contact 552. Obviously, they are always collinearly aligned. As the contact 552 oscillates in response to the elastomer 519, there is also a wiping action between the contacts 502 and 552.

The present disclosure also inherently includes a method of constructing a device in accordance with the present invention. In addition, there is a method of minimizing contact resistance when making temporary contact between the device under test and the test fixture having the test contact. Minimizing the resistance is the goal of the scraping action described above. The test fixture has force applying and sensing clamp contacts for receiving the test contacts and includes at least some or all of the following steps:

a. Alignably align the sensing and force contact

b. elastically positioning the sensing contact in a plane above the force-applying contact, but on the side of the force-applying contact,

c. making the test contact in physical contact with the sensing contact

d. deflecting the sensing contact by testing the contact, causing the sensing contact to scratch the test contact during deflection

Furthermore, the method may further comprise the following steps or components thereof: by configuring the force-applying contact to have a swing in response to the impact, such that the force-applying contact is deflectable when it hits the test contact.

Alternative embodiment

Further improvements to the embodiments described and illustrated above may further be used in several device packages, including flat or curved contact pads, in addition to being used with leaded devices. More specifically, this embodiment is applicable if the pads are out of plane due to intentional or erroneous, i.e., non-planar. In addition, this embodiment is also applicable if it is necessary to scrape the oxide more completely from the contact. Finally, this system has its preferred application if the force and sensing contacts do not short-circuit when the DUT is not present.

Figures 34 through 38 illustrate an alternate embodiment with a DUT with leads, although the same is true for the absence of leads and pads. The device under test (DUT) 1 has a plurality of leads 502 that are in contact by sensing contacts 654. As explained in the previous embodiment, the lead 502 has a flat portion at its end, an adjacent curved portion, an angled portion extending from the curved portion, and another flat portion that extends to the DUT. As will be explained in more detail below, the curved and angled portions provide the best position for the contacts.

The sensing contacts are preferably made of a spring conductive material and held in spaced relationship by the non-conductive blocks 660 and 662 from the contacts to other circuits to test the DUT. Contact 654 is also held in a spaced relationship by retainers 668, 670, 672.

To replace the force-applying contact 552, which provides a spring-type force-applying contact 652. Spring contacts 652 are shown in larger detail in Figures 39-42. Spring pin contacts as known in the art can be replaced by those shown in U.S. Patent No. 5,014,004, U.S. In general, the springs shown have an internal bias with a telescoping core as shown, or conversely include a biasing element in the core.

The force spring contact 652 has an upper pin that is in contact with the lead on the DUT Section 700, a lower contact 702 in contact with a load plate or the like to carry signals back to other test electronics, and a telescoping portion including a spring biasing member 706 and a change in distance between the upper and lower portions (not The central spring portion 704 is shown). Preferably, it engages the punctiform end of the force-applied contact with the lead 502 for, for example, a curved portion or an angled portion or a non-planar/non-orthogonal surface of both the curved portion and the angled portion. This has the advantage that the contact surfaces of more pins are bonded to the leads and the movement of either of them tends to scratch any oxide from the contacts. Similarly, the concept of engaging curved and angled portions can also be applied to other embodiments described above and similar advantages can be obtained. In the case of a vertically oriented spacer spring pin 700, the advantage of selecting this contact point is even greater.

The upper tip 710 of the upper portion 700 is shown in Figures 41 and 43. Tip 710 is preferably a conical or point having a generally flat top 712. The top portion may also be dome shaped or have a pointed or wedge shape or any other shape disclosed in the remainder of the text. In the preferred embodiment, the conical top portion has a plurality of facets/grooves or grooves 720 that extend from the tip end toward the lower end of the conical portion. Facet 720 provides access to debris that is normally oxidized material that is detached from the DUT leads. These facets increase the likelihood of directing the debris to a location that does not cause a short circuit or interfere with the quality of the test.

Sensing contact 654 has contact ends that can be in a variety of forms. It is possible to use fork-shaped tines 64a, 64b, 64c (Fig. 6 and Fig. 41). Optionally, it may utilize a flat forked tines 764 (Fig. 41), or a circular looped end 770 as shown in Fig. 42.

The looped end 770 includes an aperture 772 that is not in contact with the force-applying contact member and that is sized to receive at least a portion of the spring pin cone that will pass therethrough. However, when the DUT does not appear, in this embodiment, a portion of the force-applying member, that is, the bracket 780 between the upper portion and the spring portion in the preferred embodiment, will pass through the ring without feeling The contact 654 is electrically contacted. To further ensure that there will be no contact therebetween, the outer surface of the spring pin (with the exception of the contact point) may be coated with a non-conductive barrier or coating. Similarly, the inner surface of the ring end (or the sensing contact in the previous embodiment) may be coated with a non-conductive material to more ensure uncontact in the case of misalignment.

It can also be configured such that electrical contact occurs when the DUT is removed, so the force applied and sense contacts will be shorted, allowing the circuit to test continuity and determine if a DUT is present. This will be a clear indication of the error in the placement of the DUT of the DUT, test device or test device. External circuitry can detect these or other conditions and notify the operator or stop processing.

The description of the present invention and its applications are intended to be illustrative, and are not intended to limit the scope of the invention. Variations or modifications of the embodiments disclosed herein are possible, and those skilled in the art will understand the practical alternatives and equivalents of the various elements of the embodiments. These and other variations and modifications can be made to the embodiments disclosed herein without departing from the scope and spirit of the invention.

1‧‧‧Device under test / DUT

2‧‧‧Terminals/Leads/Solders/(Contact) Pads/Contacts

3, 503‧‧‧ load board

4‧‧‧(contact) pads

5‧‧‧Tester

6‧‧‧Load board substrate

9‧‧‧Electrical connection

10‧‧‧(insert) partition

20‧‧‧ (conductive) contacts

50, 60, 70, 90, 100, 110, 130, 140‧‧‧ design

51, 61, 71, 81, 91, 101, 111, 131, 141‧‧‧ shell

52, 112, 172, 182, 192‧‧‧ force contact

53, 73, 103‧ ‧ holes

54, 74, 84, 94, 104‧‧‧ Sensing (electricity Pressure) contact

54a‧‧‧Face arm/teeth

54b‧‧‧ bump

54c‧‧‧Contact points

62‧‧‧(force) contact

64‧‧‧Sensing (voltage) contacts/parts/contacts

64a‧‧‧Flat Part/Tine

64b‧‧‧Rising part/fork/spike

64c‧‧‧fork/tip/spigot

72, 92, 102, 152‧‧‧ force (current) contacts

75‧‧‧ (fixed) part

76‧‧‧Free part

77‧‧‧Hinged part

78‧‧‧fork part

79A‧‧‧ Conductive layer

79B‧‧‧Electrical insulation

80‧‧‧Model design

82‧‧‧Power (current) contacts/contacts

85‧‧‧Extensions

95, 105‧‧‧ pole

114, 154, 164, 204‧‧‧ Sensing contacts

119‧‧‧ pads

134‧‧‧Sensing (voltage) contacts/contacts Piece

Section 134b‧‧‧

134c‧‧‧Contacts/sections

134d‧‧‧Contacts

142, 772‧‧‧ hole

144, 184, 194, 214, 554, 654‧‧ (sensing) contacts

155, 177, 187, 197, 206, 217, 710 ‧ ‧ cutting-edge

162‧‧‧ (force) contact

165‧‧‧ Arm

166‧‧‧Horizontal extensions/contacts

167‧‧‧ Tips/contacts

169‧‧‧ vertical axis

174‧‧‧ (sensing) contact/arm

End of 175, 185, 195‧‧

176, 186, 196, 216‧‧ ‧ lateral extension

202‧‧‧ (central) force contact/contact

212‧‧‧ (Central) Force Contact

215‧‧‧End / Contact

501‧‧‧Leading device (DUT)

502‧‧‧Contacts/leads

502a‧‧‧Leader

519‧‧‧Pillars/Components/Elastomers

519a‧‧‧Second biasing block / elastic element

552‧‧‧(force) contact/tip/force contact tip

552a‧‧‧ dent

554a‧‧‧(pad package) tines

554b‧‧‧ tines

600‧‧‧Swing pin/(force) contact

602‧‧‧ inner week

620‧‧‧Flange

652‧‧‧ force contact/(force) spring contact

660, 662‧‧‧ non-conducting blocks

668, 670, 672‧‧‧ retainers

700‧‧‧Upper section/spring pin/upper part

702‧‧‧ Lower contact

704‧‧‧Central spring section

706‧‧‧Spring biasing parts

712‧‧‧ top

720‧‧・facet/groove

764‧‧‧forked tines

770‧‧‧circle

780‧‧‧ bracket

A, B‧‧‧ terminals

I‧‧‧current

V‧‧‧ voltage

Figure 1 is a side elevational view of a portion of test equipment for receiving a device under test (DUT) for standard electrical testing.

Figure 2 is a side view of the test equipment of Figure 1 electrically coupled to the DUT.

Figure 3 is a side elevational view of a portion of test equipment for receiving a device under test (DUT) for Kelvin testing.

Figure 4 is a side elevational view of the test equipment of Figure 3 electrically coupled to the DUT.

Figure 5 is a plan view of a first design of the force-applying and sensing contacts on the test equipment.

Figure 6 is a plan view of a second design of the force-applying contact and sensing contact on the test equipment.

Figure 7 is a plan view of a third design of the force-applying and sensing contacts on the test equipment.

Figure 8 is a plan view of a fourth design of the force-applying contact and sensing contact on the test equipment.

Figure 9 is a plan view of a fifth design of the force-applying contact and sensing contact on the test equipment.

Figure 10 is a plan view of a sixth design of the force-applying and sensing contacts on the test equipment.

Figure 11 is a plan view of a seventh design of the force applying contact and sensing contact on the test equipment.

Figure 12 is a side elevational view of two sets of terminals/contacts for the test equipment of Figures 3 and 4 electrically coupled to the DUT.

Figure 13 is a side cross-sectional view of the sample geometry of the sense (voltage) contact on its path from the terminal on the device under test to the contact pad on the load board.

Figure 14 is a side cross-sectional view of another sample geometry of the sensing (voltage) contact on its path from the terminal on the device under test to the contact pad on the load board.

Figure 15 is a side elevational view of a pair of sensing contacts having tips that are angled outwardly from a central force applying (current) contact.

Figure 16 is a top plan view of a pair of sensing contacts, at their ends, the pair of sensing contacts including laterally extending portions that extend toward each other.

Figure 17 is a top plan view of a pair of sensing contacts, at their ends, the pair of sensing contacts including laterally extending portions that extend toward each other.

Figure 18 is a top plan view of a single sensing contact, at the end of which the sensing contact includes a laterally extending portion that extends midway around the force applying contact.

Figure 19 is a top plan view of a single sensing contact, at the end of which the sensing contact includes a laterally extending portion that does not extend midway around the force applying contact.

Figure 20 is a side elevational view of a pair of sensing contacts having tips that are inclined toward one another and intersect each other above or beside the central force-applying contact.

Figure 21 is a top plan view of a pair of sensing contacts, at their ends, the pair of sensing contacts including laterally extending portions that extend upward beyond the plane of the paper.

Figure 22 is a perspective schematic view of an integrated circuit package with leads and its Kelvin contact system.

Figure 23 is an enlarged perspective view of the system of Figure 22 with a portion removed for clarity.

Fig. 24 is a view similar to Fig. 23, but viewed from the other side.

Figure 25 is a side elevational view of a system applied to a device with leads in a squeezed state.

Figure 26 is a view similar to Figure 25 except that the elastic portion is removed.

Fig. 27 is a view similar to Fig. 25 except that the extruded state and the sensing contact are designed to only collide with the front portion of the lead protruding from the device.

Figure 28 is a view similar to Figure 27, but viewed from the other side, and the solution has upwardly bent tines (instruments) to begin to contact the device more quickly, thereby providing greater Adaptability.

Fig. 29 is a schematic view showing both the unsqueezed state and the pressed state of the concept of connecting only the front portion of the device lead.

Fig. 30 is a schematic view similar to Fig. 29, showing the uncompressed state and the squeezed state of the double-pronged concept of sensing the tines across the force-applying contact.

Figure 31 is a perspective view showing the urging contact of the fork-shaped sensing lead across the reduced tip thickness.

Figure 32 is a perspective view similar to Figure 31 showing a single-sided sensing lead and a biasing contact with offset.

Figure 33 is a perspective view similar to Figure 29.

Figure 34 is a top perspective view similar to Figure 22 but for an alternate embodiment.

Figure 35 is a bottom perspective view similar to Figure 22 but for an alternate embodiment.

Figure 36 is a side plan view of the object of Figure 34.

Figure 37 is an exploded perspective view of Figure 34 with additional environment.

Figure 38 is a bottom perspective view of the object of Figure 37.

Figure 39 is an enlarged side plan view of an alternative embodiment.

Figure 40 is a top perspective view of an alternate embodiment.

Figure 41 is an enlarged perspective view of an alternative embodiment.

Figure 42 is an enlarged top perspective view of an alternate embodiment.

Figure 43 is an enlarged side plan view of an alternative embodiment.

1‧‧‧Device under test / DUT

2‧‧‧Terminals/Leads/Solders/(Contact) Pads/Contacts

3‧‧‧Load board

4‧‧‧(contact) pads

5‧‧‧Tester

6‧‧‧Load board substrate

10‧‧‧(insert) partition

20‧‧‧ (conductive) contacts

Claims (11)

  1. A device for forming a plurality of temporary mechanical and electrical connections between devices under test (DUTs) having a plurality of terminals, comprising: a plurality of electrically conductive force-applying contacts extending toward a device under test and being Deflecting, each of the plurality of force-applying contacts is laterally aligned to correspond to a terminal; the force-applying contacts are a plurality of vertically oriented spaced spring biased pins, each pin comprising a contact point aligning to engage the terminals on a portion of the terminal that is not orthogonal to the terminal; and a plurality of electrically conductive sensing contacts, each of the plurality of sensing contacts A sensing contact is laterally arranged to correspond to a force applying contact and a terminal, each of the plurality of sensing contacts extending toward the device under test (DUT) a force contact; wherein each of the plurality of sensing contacts comprises a freely moving portion that elastically extends toward the device to be tested; wherein the sensing contact is coupled to the corresponding force contact side Separating; and wherein the free portion includes An aperture at its end that is spaced sufficiently to permit passage of the force-applying contact.
  2. The device of claim 1, wherein the end includes a ring having a small aperture, and wherein the force-applying contact is aligned for receipt within the aperture.
  3. The device of claim 1, wherein the force applying contact is configured to engage the terminal at a curved portion of the terminal.
  4. The device of claim 1, wherein the force contact member group An angled portion of the terminal engages the terminal.
  5. The device of claim 3, wherein the spring contact comprises an upper portion having a conical tip.
  6. The device of claim 3, wherein the spring contact comprises an upper portion having a dome tip.
  7. The device of claim 1, wherein the force-applying contact comprises a substantially point-like upper tip, and wherein the tip includes at least one facet channel in the tip for debris removal.
  8. The device of claim 7, wherein the facet channel is a recess extending from the tip and away from the tip.
  9. The device of claim 1, wherein the sensing contact comprises a ring portion having a small hole at an end thereof, and wherein the force applying contact has a predetermined diameter, the predetermined diameter being customized It can be received in the aperture without electrical contact with the ring.
  10. The device of claim 1, wherein the sensing contact comprises a ring portion having a small hole at an end thereof, and wherein the force applying contact has a bracket separated from the tip, the bracket is compared The aperture in the sensing contact is wider, and wherein the force-applying contact is biased upward such that when the device under test is removed, the bracket is free to be removed when the device under test is removed The sensing contacts make electrical contact.
  11. The device of claim 9, wherein the ring portion includes an inner surface, and wherein the pin includes an outer surface, and wherein at least one of the inner or outer surfaces includes a non-conductive barrier to prevent A short circuit occurred between them.
TW100137922A 2011-10-19 2011-10-19 Improved electrically conductive kelvin contacts for microcircuit tester TWI503553B (en)

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KR101573450B1 (en) * 2014-07-17 2015-12-11 주식회사 아이에스시 Test socket
CN107102250A (en) * 2016-02-22 2017-08-29 杰冯科技有限公司 Kelvin contact part component and its installation method
CN106375925B (en) * 2016-09-12 2019-02-26 歌尔股份有限公司 Earphone testboard, earphone test device and earphone test method

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US20040209491A1 (en) * 1999-07-27 2004-10-21 Mitsubishi Denki Kabushiki Kaisha Test socket, method of manufacturing the test socket, test method using the test socket, and member to be tested
TW480692B (en) * 1999-10-12 2002-03-21 Advantest Corp Contact structure having silicon finger contactors and total stack-up structure using same
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US20090066922A1 (en) * 2006-05-18 2009-03-12 Nikon Corporation Exposure method and apparatus, maintenance method and device manufacturing method

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