Work press assembly for test handler

An exemplary work press assembly for a test handler includes a presser and a guide frame. The presser is configured to secure a device under test (DUT) and press the DUT into a socket for testing. The guide frame is configured to receive guide pins of the socket. The presser extends through an opening of the guide frame, and the guide frame is sandwiched between a first presser portion and a second presser portion. The presser is formed of a first material having a first coefficient of thermal expansion (CTE), and the guide frame is formed from a second material having a second CTE that is less than the first CTE. In some embodiments, a thermal insulation layer(s) separates the presser from the guide frame. In some embodiments, a spacing between sidewalls of the presser and sidewalls of the guide frame is configured to accommodate thermal expansion of the presser.

BACKGROUND

Testing is an important step in ensuring an integrated circuit's reliability, integrity, and performance. Thermal management during testing, such as thermal management of the integrated circuit and thermal management of testing systems performing the tests, has become a challenge. Although existing thermal management techniques have been generally adequate for their intended purposes, they have not been entirely satisfactory in all respects.

DETAILED DESCRIPTION

The present disclosure relates generally to testing of integrated circuit (IC) and/or semiconductor devices, and more particularly, to test handlers for IC testing systems.

The following disclosure provides many different embodiments, or examples, for implementing different features of the invention. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. For example, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact and may also include embodiments in which additional features may be formed between the first and second features, such that the first and second features may not be in direct contact. In addition, spatially relative terms, for example, “lower,” “upper.” “horizontal,” “vertical,” “above,” “over,” “below,” “beneath,” “up.” “down,” “top,” “bottom,” etc. as well as derivatives thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) are used for case of the present disclosure of one features relationship to another feature. The spatially relative terms are intended to cover different orientations of the device including the features. The present disclosure may also repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.

Further, when a number or a range of numbers is described with “about,” “approximate,” and the like, the term is intended to encompass numbers that are within a reasonable range considering variations that inherently arise during manufacturing as understood by one of ordinary skill in the art. For example, the number or range of numbers encompasses a reasonable range including the number described, such as within +/−10% of the number described, based on known manufacturing tolerances associated with manufacturing a feature having a characteristic associated with the number. For example, a material layer having a thickness of “about 5 nm” can encompass a dimension range from 4.5 nm to 5.5 nm where manufacturing tolerances associated with depositing the material layer are known to be +/−10% by one of ordinary skill in the art. Furthermore, given the variances inherent in any manufacturing process, when device features are described as having “substantial” properties and/or characteristics, such term is intended to capture properties and/or characteristics that are within tolerances of manufacturing processes. For example, “substantially vertical” or “substantially horizontal” features are intended to capture features that are approximately vertical and horizontal within given tolerances of the manufacturing processes used to fabricate such features—but not necessarily mathematically or perfectly vertical and horizontal.

Thermal management during IC testing, such as thermal management of an IC being tested and thermal management of a testing system performing the tests, has become a challenge. For example, thermal management of the IC has been observed to impact reliability of a test handler of a test system. As an example, a work press assembly of a test handler may be formed of a thermally conductive material to facilitate heat transfer between a thermal source and a device under test, which leads to thermal expansion of the work press assembly. The thermal expansion can cause alignment/guide means of the work press assembly (e.g., guide holes) to laterally shift relative to alignment/guide means of a test interface (e.g., guide pins). Alignment/guide means of the work press assembly may thus physically contact and/or rub against the alignment/guide means of the test interface, which causes abnormal wear of the work press assembly and degrades its reliability. Alignment/guide means of the work press assembly can also become stuck in alignment/guide means of the test interface because of the lateral shifting, which can destroy vacuum means securing the device under test to the work press assembly and cause the work press assembly to drop and damage the device under test.

The present disclosure addresses such challenges by providing an improved work press assembly for a test handler that can reduce thermal conductivity, and thus thermal expansion, of an outer, alignment/guide region thereof. The disclosed work press assembly separates an outer, alignment/guide region from a presser region of the work press assembly. A coefficient of thermal expansion and a thermal conductivity of a material of the alignment/guide region is less than a coefficient of thermal expansion and a thermal conductivity, respectively, of a material of the presser region, which reduces and/or prevents thermal expansion of the alignment/guide region while allowing the presser region to facilitate heat transfer between a thermal source and a device under test. Thermal insulation layers, such as fiberglass layers, can be formed between the alignment/guide region and the presser region to further reduce thermal conductivity and/or thermal expansion of the alignment/guide region. For example, the thermal insulation layers can significantly reduce and/or prevent heat transfer from the presser region to the alignment/guide region. Since the presser region is formed of a thermally conductive material to facilitate heat transfer and will thus experience thermal expansion, dimensions of the alignment/guide region and the presser region are configured to provide expansion buffer areas and/or minimize contact therebetween. For example, the dimensions are configured to provide spacings between the alignment/guide region and the presser region, where the spacings are configured to accommodate thermal expansion of the presser region. Reducing and/or preventing thermal expansion of the alignment/guide region of the work press assembly, along with accommodating for thermal expansion of the presser region, can reduce and/or prevent lateral shifting of alignment/guide means of the work press assembly relative to alignment/guide means of a test interface, thereby improving reliability of the work press assembly and/or quality of tested devices (i.e., reduce damage from dropping). Different embodiments may have different advantages, and no particular advantage is required of any embodiment.

FIG.1is a block diagram of an exemplary test system10for IC testing, in portion or entirety, according to various aspects of the present disclosure.FIG.2is a block diagram of a test handler, in portion or entirety, of test system10according to various aspects of the present disclosure.FIG.3is a cross-sectional view of the test handler, in portion or entirety, ofFIG.1andFIG.2according to various aspects of the present disclosure.FIG.4is a cross-sectional view of test system10, in portion or entirety, according to various aspects of the present disclosure.FIG.5is an exploded perspective view of a work press assembly, in portion or entirety, of the test handler ofFIGS.1-4according to various aspects of the present disclosure.FIG.6is a cross-sectional view of the work press assembly of the test handler ofFIG.5along line A-A when assembled, in portion or entirety, according to various aspects of the present disclosure.FIGS.1-6are discussed concurrently herein for case of description and understanding.FIGS.1-6have been simplified for the sake of clarity to better understand the inventive concepts of the present disclosure. Additional features can be added in test system10and/or components thereof (e.g., the test handler and/or the work press assembly thereof), and some of the features described below can be replaced, modified, or eliminated in other embodiments of test system10and/or components thereof.

Test system10includes a test handler15, a test interface20, and a tester25(also referred to as automatic/automated test equipment (ATE)). Test system10is configured to test a quality and/or a functionality of a device under test (DUT), such as a DUT30. For example, test handler15places DUTs in mechanical and/or electrical contact with tester25via test interface20, and tester25performs tests on the DUTs and evaluates performance and/or characteristics thereof. Based on the test results (e.g., pass or fail), the DUTs are classified and/or sorted by test handler15. Test system10can evaluate DUTs' electrical characteristics, reliability, behavior, other characteristics and/or behaviors, or combinations thereof in response to various input and/or conditions (e.g., particular temperatures). In some embodiments, test system10evaluates electrical characteristics and/or operation of DUTs at high temperatures. In some embodiments, test system10subjects DUTs to reliability tests, such as thermal cycling tests and/or thermal shock tests. In some embodiments, test system10performs final tests on DUTs.

DUT30can be a semiconductor and/or IC device, semiconductor and/or IC chip, semiconductor and/or IC package, or combinations thereof. In the depicted embodiment, DUT30is an IC package having vertically stacked chips, such as a three-dimensional IC (3DIC) package or a 2.5D IC package (e.g., an IC package that implements an interposer). For example, DUT30can be a chip-on-wafer-on-substrate (CoWoS) package, an integrated-fan-out (InFO) package, a system-on-IC (SoIC) package, a multi-dimensional package that implements local silicon interconnect (LSI) (e.g., a CoWoS-L package or an InFO-L package), other 3DIC and/or 2.5D IC package, or a hybrid package that implements a combination of multichip packaging technologies. Each chip of the IC package includes at least one functional IC, such as an IC that performs a logic function, a memory function, a digital function, an analog function, a mixed signal function, a radio frequency function, an input/output (I/O) function, a communications function, a power management function, other function, or combinations thereof. In some embodiments, a chip has multiple functions, such as a system-on-chip (SoC). In some embodiments, the SoC has an entire system, such as a computer system, thereon.

DUT30has a surface30A and a surface30B, which may be referred to as a top surface and a bottom surface, respectively. In some embodiments, DUT30has a width (e.g., an x-dimension) and/or a length (e.g., a y-dimension) that is greater than about 45 mm. In such embodiments, a surface area of surface30A and/or surface30B is greater than about 2025 mm2. DUT contacts35are disposed along surface30B and facilitate electrical interconnection of DUT30to test interface20/tester25. DUT contacts30are formed from an electrically conductive material. DUT contacts30can be arranged on surface30B to form a contact array/pattern, such as a ball grid array. In some embodiments, DUT contacts35are solder balls.

Test interface20provides a mechanical and electrical interface between tester25and DUT30, and test interface20routes signals between tester25and DUT30, such as test signals from tester25to DUT30and response signals from DUT30to tester25. Test interface20can include a load board40, such as a printed circuit board (PCB), and a socket42mounted on load board40. Load board40is electrically connected to tester25, and socket42is electrically connected to load board40. Load board40and/or socket42can be attached to and/or form a portion of test handler15and/or tester25. In some embodiments, load board40and/or socket42are attached to and/or form a portion of a test head. Configurations of test interface20, load board40, and socket42depend on a type and/or a configuration of DUTs being tested by test system10and/or a type of test(s) performed on DUTs by test system10.

Socket42includes a socket base44and a socket guide46. Socket base44includes a contactor48having socket contacts49, such as a probe card having probe pins, and a cavity50therein for receiving DUT30. Socket contacts49have load board-facing ends and DUT-facing ends. Load board-facing ends are physically and/or electrically connected to load board contacts50of load board40. DUT-facing ends are configured and arranged to physically and/or electrically connect to DUT contacts35when DUT30is inserted into cavity50and pressed into contactor48by test handler15as described below. Socket contacts49can be spring-loaded pins (e.g., pogo pins), various-shaped contacts disposed in elastomer, particle interconnects, other suitable types of contacts and/or interconnects, or combinations thereof. Socket contacts49and load board contacts (pads)50are formed from an electrically conductive material.

Socket guide46includes a guide plate52having guide pins54extending therefrom and an opening56therein that exposes contactor48of socket base44. Socket guide46and socket base44are configured to facilitate seamless inserting and removing of DUTs by test handler15, including proper positioning and alignment of DUT30within socket42(i.e., DUT contacts35are aligned with and adequately contact socket contacts49during testing). For example, dimensions of opening56, dimensions of cavity50, and dimensions of guide plate52and/or guide pins54are configured to receive, guide, and secure test handler15into a position in socket42that establishes contact and alignment of DUT contacts35and socket contacts49. In the depicted embodiment, dimensions of opening56are greater than dimensions of cavity50, such that a portion of test handler15(e.g., a work press assembly thereof) can move through socket guide46to insert DUT30into socket base44with minimal lateral shifting. In some embodiments, dimensions (e.g., widths) and locations of guide pins54are configured relative to test handler15(e.g., accounting for dimensions and locations of guide holes of test handler15) to minimize lateral shifting of test handler15as it presses DUT30into socket42.

Test handler15can include a loader60, a thermal conditioning area65, an in-shuttle area70(having in-shuttles72), a test area75, an out-shuttle area80(having out-shuttles82), a thermal conditioning area85, and an unloader90. Loader60can receive a carrier tray having DUTs for testing and transfer the DUTs from the carrier tray to a test tray, which is moved to thermal conditioning area65. In thermal conditioning area65, the DUTs can be thermally conditioned (e.g., heated and/or cooled) to desired temperatures for testing. For example, the test tray and/or the DUTs are placed on a hot plate and pre-heated to a desired temperature. The thermally conditioned DUTs are then moved to in-shuttle area70. In in-shuttle area70, each DUT can be placed in a respective in-shuttle72and moved to test area75for testing.

In test area75, work press assemblies100move and position DUTs30for testing. Each work press assembly100has a respective arm101that moves it within test area75and/or moves it in and out of socket42. For example, when test area75receives an in-shuttle (e.g., In Shuttle2) with a DUT for testing, an arm (e.g., arm101) can move its respective work press assembly (e.g., work press assembly100) to the in-shuttle and proximate to the DUT, such that the work press assembly can pick up and secure the DUT thereto. The arm can then move the respective work press assembly (which is holding the DUT) to and press the respective work press assembly into socket42of test interface20. The arm/work press assembly apply sufficient pressure to ensure that the DUT is placed in physical and electrical contact with socket42for testing. After tester25tests the DUT, the arm can move the respective work press assembly to an out-shuttle (e.g., Out Shuttle2), such that the work press assembly can release/place the tested DUT in the out shuttle, which then moves the tested DUT to out-shuttle area80.

In some embodiments, in out-shuttle area80, the tested DUTs are removed from out-shuttles82and placed into a test tray and/or a carrier tray. In some embodiments, the out-shuttles82transfer the tested DUTs to unloader90or thermal conditioning area85. Unloader90can sort, classify, and bin the tested DUTs based on the test results. For example, unloader90sorts the tested DUTs based on pass/fail criteria, such that the tested DUTs are sorted into passed devices/packages and failed devices/packages. In some embodiments, the tested DUTs are placed into carrier trays based on their classifications/binning. In some embodiments, a tray of the tested DUTs and/or the tested DUTs are moved to thermal conditioning area85before sorting by unloader90. In thermal conditioning area85, the tested DUTs can be thermally conditioned (e.g., heated and/or cooled) to desired temperatures. For example, after high temperature testing, the tested DUTs can be cooled to ambient temperature.

In-shuttles72can move between in-shuttle area70and test area75, and out-shuttles82can move between out-shuttle area80and test area75. For example, when a DUT is moved from the test tray to an in-shuttle, the in-shuttle transfers the DUT from the in-shuttle area70to test area75. When the DUT is removed from the in-shuttle by a work press assembly in test area75, the in-shuttle can return to in-shuttle area70to receive another DUT. The work press assembly transfers the tested DUT from the in-shuttle to test interface20/tester25. After testing is performed on the DUT, the work press assembly transfers the tested DUT from test interface20/tester25to an out-shuttle. When the work press assembly releases the tested DUT into and/or on the out-shuttle, the out-shuttle transfers the tested DUT from test area75to out-shuttle area80. When the DUT is removed from the out-shuttle (e.g., transferred from the out-shuttle to unloader90), the out-shuttle can return to test area75to receive another tested DUT.

Work press assembly100includes a thermal source102, a contact block104(also referred to as a contact blade and/or a contact head), a connector106, and a guide frame108.

Thermal source102can maintain thermal conditions of DUT30(e.g., maintain a desired temperature of DUT30) and/or adjust thermal conditions of DUT30(e.g., adjust a temperature of DUT30) during testing. For example, thermal source102transfers thermal energy to/from DUT30to heat and/or cool DUT30during testing. In some embodiments, thermal source102includes a ceramic thermal pad and/or other resistor-based thermal source, such as a thermal rod. In some embodiments, thermal source102includes a cooler for circulating a cooling medium (e.g., cooled air) and/or a heater for circulating a heating medium (e.g., heated air). In some embodiments, thermal source102functions as a heat sink to reduce a DUT's temperature. In some embodiments, thermal source102can include a Peltier device.

Contact block104has a body110having a DUT-facing portion110A, a connector-facing portion110B, and a middle portion110C between the DUT-facing portion110A and the connector-facing portion110B, and connector106has a body112. Contact block104and connector106(i.e., body110and body112, respectively, thereof) are formed from thermally conductive materials that facilitate a flow of thermal energy (e.g., heat) between thermal source102and DUT30, such that DUT30reaches and/or maintains desired temperature(s) during testing. Exemplary thermally conductive materials for contact block104and connector106include aluminum, copper, other suitable thermally conductive materials, alloys thereof, or combinations thereof. In some embodiments, contact block104and connector106are formed from the same material. For example, body110of contact block104and body112of connector106are formed of aluminum and/or copper. In some embodiments, contact block104and connector106are formed from different thermally conductive materials.

Contact block104is fastened to and/or fixedly attached to connector106. For example, contact block104has attachment holes114at a surface of connector-facing portion110B, connector106has attachment pins116extending from a contact block facing surface of connector106, attachment holes114are configured to receive attachment pins116, and attachment pins116are configured to insert into attachment holes114and secure connector106to contact block104. In some embodiments, attachment holes114and attachment pins116are guide/alignment holes and guide/alignment pins, respectively. In some embodiments, attachment holes114and attachment pins116are bolt holes and bolts, respectively. In some embodiments, attachment holes114and attachment pins116are tapped holes and screws, respectively. Other types of fastening configurations and/or arrangements are contemplated by the present disclosure for attachment holes114and attachment pins116.

Contact block104and connector106are configured to pick up and secure a DUT, such as DUT30, thereto, push the DUT into socket42, and apply sufficient pressure to DUT30to establish a connection between DUT30and test interface20/tester25(in particular, between DUT contacts35and socket contacts49). Contact block104and connector106can collectively be referred to as a pusher/plunger of work press assembly100.

Contact block104and connector106can be configured to pick up and secure DUT30by vacuum, thereby providing work press assembly100with a vacuum head/pusher. In the depicted embodiment, contact block104has channels120in body110, where each channel120is fluidly and/or communicatively connected to a respective nozzle122. Connector106has channels124in body112, where each channel124is fluidly and/or communicatively connected to a respective recess/groove126at a contact block facing surface of connector106and a recess/groove128at a thermal source facing surface of connector106. Channels120of contact block106are fluidly and/or communicatively connected to recess/grooves126and channels124of connector106. Channels120, nozzles122, channels124, recess/grooves126, recess/groove128, or combinations thereof can provide contact block104/connector106with a vacuum suction system for picking up and holding onto DUTs. For example, channels120, nozzles122, channels124, recess/grooves126, recess/groove128, or combinations thereof are connected to a vacuum generator/source/system (e.g., a vacuum pump) to create vacuum suction power in contact block104/connector106, such that DUT30can be vacuum suctioned/attached to nozzles (suction cups)122of contact block104. In such embodiments, channels120and channels124can be referred to as vacuum channels/lines. Gaskets130can be provided in recess/grooves126and recess/groove128, for example, to seal gaps/interfaces between connector106and contact block104/thermal source102, respectively. In some embodiments, gaskets130are O-rings.

Guide frame108forms an outer ring of work press assembly100and bounds the presser/plunger (i.e., contact block104/connector106) of work press assembly100. Guide frame108has an outer frame108A and an inner frame108B. An opening140in guide frame108is defined by inner frame108B, and the presser of work press assembly100, such as connector-facing portion110B of contact block104, extends through opening140. Outer frame108A has a thickness T1, and inner frame108B has a thickness T2. Thickness T2is less than thickness T1, and inner frame108B protrudes from outer frame108A, such that inner frame108B forms an inner, recessed ledge of guide frame108that contact block104and connector106secure therebetween when assembled. In the depicted embodiment, a top surface of inner frame108B is recessed from a top surface of outer frame108A, and a bottom surface of inner frame108B is recessed from a bottom surface of outer frame108A.

Guide frame108is configured to guide and secure work press assembly100into a position in socket42that establishes contact and alignment of DUT contacts35and socket contacts49. For example, outer frame108A has guide holes142therein for receiving guide pins54of socket guide46. Dimensions and locations of guide holes142are configured relative to socket guide46(e.g., accounting for dimensions and locations of guide pins54thereof) to align/guide and/or minimize lateral shifting of work press assembly100. For example, widths of guide holes142are about 0.7% to about 1.5% greater than (i.e., slightly greater than) widths of guide pins54. In some embodiments, a width W of guide holes142is about 3.5 mm to about 4.5 mm. In some embodiments, width W of guide holes142is about 4.02 mm+0.02 mm. In some embodiments, guide frame108rests upon socket guide46during testing. In some embodiments, socket42is configured to prevent over-pressing (i.e., too much pressure).

To reduce and/or prevent thermal conduction and thus thermal expansion of an outer region of work press assembly100(in particular, a region of work press assembly100that positions and aligns the presser of work press assembly100and thus DUT30relative to socket42) and shifting of guide holes142, guide frame108is formed from a material having a thermal conductivity and a coefficient of thermal expansion (CTE) that is less than a thermal conductivity and CTE, respectively, of a material forming the presser of work press assembly100(i.e., contact block104and/or connector106). For example, a CTE of a material forming guide frame108is less than a CTE of a material forming body110of contact block104, and in some embodiments, is also less than a CTE of a material forming body112of connector106. In some embodiments, guide frame108(i.e., outer frame108A/inner frame108B) is formed from a material having a CTE that is less than or equal to about 12×10−6/K, and the presser of work press assembly100(i.e., contact block104and/or connector106) is formed from a material having a CTE greater than 12×10−6/K. Materials having a CTE greater than 12×10−6/K may not meaningfully prevent and/or reduce thermal conduction and/or thermal expansion of guide frame108and thus may still provide a work press assembly that suffers from guide hole shifting as described herein. In some embodiments, guide frame108is formed of aluminum silicon carbide (AlSiC). In some embodiments, guide frame108is formed of steel. In some embodiments, guide frame108is formed of a ceramic material, such as silicon nitride (SiN), aluminum oxide (AlO), aluminum nitride (AlN), other suitable ceramic material, or combinations thereof.

Guide frame108can further include thermal insulation layer(s)150. Thermal insulation layers150are disposed on inner frame108B. In the depicted embodiment, thermal insulation layers150are disposed on the top surface and the bottom surface of inner frame108B, such that inner frame108B is sandwiched between thermal insulation layers150. In such embodiments, inner frame108B is separated from and does not physically touch contact block104and/or connector106. Thermal insulation layers150include a material having a thermal conductivity that is less than a thermal conductivity of the material of guide frame108, such that the material of thermal insulation layers150can prevent or significantly reduce a transfer of thermal energy (e.g., heat) between the presser of work press assembly100(i.e., contact block104/connector106) and guide frame108. In some embodiments, thermal insulation layers150are fiberglass layers. In some embodiments, a thermal conductivity of thermal insulation layers150is less than or equal to about 0.06 W/mK (Watts per meter-Kelvin), where thermal conductivity greater than 0.06 W/mK may not meaningfully prevent and/or reduce thermal energy transfer from the presser of work press assembly100to inner frame108B.

Thermal insulation layers150on the top surface of inner frame108B (e.g., connector-facing surface) have a thickness T3, and thermal insulation layers150on the bottom surface of inner frame108B (e.g., contact block-facing surface) have a thickness T4. Thickness T3and/or thickness T4is greater than or equal to about 0.8 mm, where thermal insulation layers150having thicknesses less than 0.8 mm may not meaningfully prevent and/or reduce thermal energy transfer from the presser of work press assembly100to inner frame108B. In the depicted embodiment, thickness T3and thickness T4are the same. In some embodiments, thickness T3and thickness T4are different. Thickness T2of inner frame108B, thickness T3of thermal insulation layers150, and thickness T4of thermal insulation layers150are configured to ensure that an inner, recessed ledge (a total inner frame) of guide frame108has a total thickness (e.g., a thickness T5) that is less than thickness T1of outer frame108A.

The present disclosure contemplates various configurations and arrangements of thermal insulation layers150on inner frame108B. In the depicted embodiment, inner frame108B forms a rectangular ring, and each side of the rectangular ring has a respective thermal insulation layer150formed thereon. In some embodiments, lengths and/or widths of the thermal insulation layers150are less than lengths and/or widths, respectively, of the respective sides of inner frame108B upon which they are disposed. In some embodiments, a thermal insulation layer150covers an entire top surface of inner frame108B or an entire top surface of one or more sides of inner frame108B (e.g., a width and a length of a thermal insulation layer is substantially the same as a width and a length of a top surface of a side of inner frame108B). In some embodiments, a thermal insulation layer150covers an entire bottom surface of inner frame108B or a bottom surface of one or more sides of inner frame108B. In some embodiments, a width of a thermal insulation layer is substantially the same as a width of a side of inner frame108B, but a length of the thermal insulation layer is less than a length of the side of inner frame108B. In such embodiments, the thermal insulation layer extends from outer frame108B to an edge of inner frame108B. In some embodiments, a thermal insulation layer is a single, continuous insulation ring (e.g., a rectangular-shaped thermal insulation layer) on inner frame108B, instead of being formed by discrete layers. In some embodiments, thermal insulation layers are arranged into any suitable pattern of thermal insulation pads on inner frame108B.

Contact block104, connector106, and guide frame108are configured to provide spacings (gaps) between guide frame108and contact block104/connector106when assembled, such as a spacing S1, a spacing S2, and a spacing S3. Spacing S1is between contact block104and guide frame108(in particular, between a sidewall of connector-facing portion110B of contact block104and a sidewall of inner frame108B of guide frame108). Spacing S2is between contact block104and guide frame108(in particular, between a sidewall of middle portion110B of contact block104and an inner sidewall of a DUT-facing portion of outer frame108A of guide frame108). Spacing S3is between connector106and guide frame108(in particular, between a sidewall of connector106and an inner sidewall of a connector-facing portion of outer frame108A of guide frame108). Spacings S1-S3allow for thermal expansion of the presser of work assembly100(i.e., contact block104/connector106) that may occur as thermal energy (e.g., heat) transfers through the presser to DUT30during testing, pre-testing, and post-testing. Spacings S1-S3thus act as expansion buffers of work press assembly100. In some embodiments, spacing S1is greater than or equal to about 0.5 mm. In some embodiments, spacing S2is greater than or equal to about 0.5 mm. In some embodiments, spacing S3is greater than or equal to about 0.5 mm. Spacings between guide frame108and the presser of work press assembly100that are less than 0.5 mm may not sufficiently accommodate thermal expansion of the presser of work press assembly100, which can increase physical contact of the presser of work press assembly100and guide frame108, such as direct contact of the presser of work press assembly100with inner frame108B and/or outer frame108A. Increased physical contact can increase transfer of thermal energy (e.g., heat) from the presser of work press assembly100to guide frame108, which can cause undesired thermal expansion of guide frame108and thus undesired shifting of guide pins142of guide frame108. Any configuration of spacings S1-S3is contemplated by the present disclosure, such as configurations where spacings S1-S3are the same or any combination of spacings S1-S3being the same and/or different.

In some embodiments, spacings S1-S3are achieved by configuring dimensions of contact block104, connector106, and guide frame108relative to one another. For example, dimensions of opening140(e.g., a width and a length) are greater than dimensions (e.g., a width and a length) of connector-facing portion110B of contact block104, such that connector-facing portion110B can extend through opening140of guide frame108without physically contacting guide frame108(in particular, sidewalls of inner frame108A and/or sidewalls of thermal insulation layers150). In another example, dimensions of connector106(e.g., a width and a length of a contact-block facing surface of connector106) and dimensions (e.g., a width and a length) of middle portion110C of contact block104are greater than dimensions of opening140(e.g., a width and a length) and less than inner dimensions of outer frame108A (e.g., a distance between inner sidewalls of outer frame108A), such that inner frame108A of guide frame108can be secured between connector106and contact block104without connector106and contact block104physically contacting outer frame108B (such as inner sidewalls thereof). In some embodiments, contact block104, connector106, and guide frame108are vertically, center aligned to provide uniform spacing around and/or between the presser of work press assembly100and guide frame108thereof. For example, spacing S1, spacing S2, and spacing S3are substantially the same on the right side and the left side of work press assembly100, such that spacings S1-S3are uniform around the presser of work press assembly100.

Guide frame108is separate from and not fixedly attached to contact block104and connector106to further reduce transfer of thermal energy to an outer region of work press assembly100. For example, guide frame108is a separate and independent component of work press assembly100, and guide frame108is not secured to contact block104and/or connector106by fasteners, such as pins, screws, bolts, nuts, etc. Instead, dimensions of contact block104, connector106, and guide frame108are configured relative to one another, such that an inner frame of guide frame108(here, formed by inner frame108B and thermal insulation layers150) is sandwiched between and secured by contact block104(in particular, middle portion110C thereof) and connector106in a manner that impedes movement of guide frame108relative to contact block104and connector106. For example, dimensions (e.g., a width and a length) of connector-facing portion110B of contact block104are less than dimensions (e.g., a width and a length) of middle portion110C of contact block104and dimensions of connector106(e.g., a width and a length of a contact block facing surface of connector106), such that a gap is formed between middle portion110C and connector106when contact block104is attached to connector106. The gap is configured to receive an inner frame/ledge of guide frame108. For example, the gap provides a distance between a connector-facing surface of middle portion110C and a contact block facing surface of connector106that is substantially the same as thickness T5(i.e., a total thickness of the inner, recessed frame/ledge of guide frame108). In some embodiments, a thickness T6of connector-facing portion110B provides the distance between the connector-facing surface of middle portion110C and the contact block facing surface of connector106. In such embodiments, thickness T6is substantially the same as thickness T5. Accordingly, when assembled, inner frame/ledge of guide frame108(here, inner frame108and thermal insulation layers150) is confined between middle portion110C of contact block104and connector106in a manner that secures guide frame108to contact block104/connector106and prevents movement of guide frame108relative to contact block104/connector106.

In some embodiments, control block104and/or connector106have thermal insulation layers, such as thermal insulation layers170disposed on the contact block facing surface of connector106. Thermal insulation layers170are similar to thermal insulation layers150. For example, thermal insulation layers170include a material having a thermal conductivity that is less than a thermal conductivity of the material of guide frame108. In some embodiments, thermal insulation layers170are fiberglass layers. In some embodiments, a thermal conductivity of thermal insulation layers170is less than or equal to about 0.06 W/mK. The present disclosure contemplates various configurations and arrangements of thermal insulation layers170on connector106and/or thermal insulation layers on contact block104.

FIG.7is a flow chart of a method200for assembling a work press assembly of a test handler, such as work press assembly100of test handler15described herein, according to various aspects of the present disclosure. At block205, method200includes receiving a first portion and a second portion of a presser of a work press assembly. The first portion is formed of a first material having a first thermal conductivity and a first coefficient of thermal expansion (CTE) and the second portion is formed of a second material having a second thermal conductivity and a second CTE. In some embodiments, the first material is the same as the second material. In some embodiments, the first portion of the presser is a contact block, such as contact block104, and the second portion of the presser can be a connector, such as connector106. In some embodiments, the first portion and the second portion of presser form a contact block. At block210, method200includes receiving a guide frame of the work press assembly. The guide frame is formed of a third material having a third thermal conductivity and a third CTE. The third thermal conductivity is less than the first thermal conductivity and the second thermal conductivity. The third CTE is less than the first CTE and the second CTE. The guide frame has an opening therein. In some embodiments, the guide frame is guide frame108.

At block215, method200includes positioning the guide frame between the first portion of the presser and the second portion of the presser. At block220, method200includes aligning the opening of the guide frame, the first portion of the presser, and the second portion of the presser. In some embodiments, the aligning includes aligning fastening means of the first portion of the presser and the second portion of the presser, such as attachment holes of the first portion of the presser with attachment pins of the second portion of the presser, or vice versa. In some embodiments, the aligning includes aligning the first portion of the presser with the opening in the guide frame, such that the first portion of the presser can be guided through the opening. In some embodiments, the aligning includes center aligning the opening of the guide frame and/or the guide frame, the first portion of the presser, and the second portion of the presser. In some embodiments, the aligning includes aligning the first portion of the presser with an inner frame of the guide frame to provide spacing between an outer frame of the guide frame and sidewalls of the first portion of the presser and/or spacing between sidewalls of the inner frame of the guide frame and sidewalls of the first portion of the presser when assembled. In some embodiments, the aligning includes aligning the second portion of the presser with an inner frame of the guide frame to provide spacing between an outer frame of the guide frame and sidewalls of the second portion of the presser when assembled. At block225, method200includes attaching the first portion of the presser and the second portion of the presser, where the guide frame is sandwiched between the first portion of the presser and the second portion of the presser and the first portion of the presser extends through the opening of the guide frame. In some embodiments, the attaching includes bringing the fastening means of the first portion of the presser and the second portion of the presser into contact, such as inserting attachment pins of the second portion of the presser into attachment holes of the first portion of the presser. In some embodiments, the attaching includes compressing the guide frame between the first portion of the presser and the second portion of the presser. For example, the first portion of the presser and the second portion of the presser are pushed onto opposite surfaces of the guide frame, such as an inner, recessed ledge of the guide frame. In some embodiments, the opposite surfaces of the guide frame can be provided by thermal insulation layers.FIG.7has been simplified for the sake of clarity to better understand the inventive concepts of the present disclosure. Additional steps can be provided before, during, and after method200, and some of the steps described can be moved, replaced, or eliminated for additional embodiments of method200.

An improved work press assembly for a test handler is disclosed herein that can reduce thermal conductivity, and thus thermal expansion, of an outer, guide pin receiving region thereof. An exemplary work press assembly for a test handler can include a presser and a guide frame. The presser is configured to pick up a device under test (DUT) and press the DUT into a socket for testing. The presser is formed of a first material having a first coefficient of thermal expansion (CTE). The guide frame is configured to receive guide pins of the socket. The presser extends through an opening of the guide frame, the guide frame is sandwiched between a first portion of the presser and a second portion of the presser, and the guide frame is formed from a second material having a second CTE that is less than the first CTE. In some embodiments, sidewalls of the presser do not physically contact the guide frame.

In some embodiments, the first material has a first thermal conductivity, the second material has a second thermal conductivity, and the first thermal conductivity is greater than the second thermal conductivity. In some embodiments, the guide frame includes a thermal insulation layer disposed between and separating the presser from the second material of the guide frame. In some embodiments, the work press further includes a thermal source connected to the presser, and the first material of the presser can transfer heat between the thermal source and the DUT (i.e., the first material is thermally conductive).

In some embodiments, a spacing is between sidewalls of the presser and sidewalls of the guide frame, and the spacing is configured to accommodate thermal expansion of the presser. In some embodiments, the first material is aluminum, copper, or a combination thereof. In some embodiments, the second material is aluminum silicon carbide, steel, ceramic, or combinations thereof. In some embodiments, the guide frame has an outer frame having a first thickness and an inner frame having a second thickness. The second thickness is less than the first thickness, and the inner frame is sandwiched between the first portion of the presser and the second portion of the presser. In some embodiments, the first portion of the presser has a first width, the second portion of the presser has a second width, and the opening of the guide frame has a third width. The first width and the second width are each greater than the third width and less than a distance between inner sidewalls of the outer frame.

An exemplary work press assembly for a test handler configured to transport a device under test (DUT) in a testing system can include a thermal source, a presser, and a guide frame. The thermal source is for managing a temperature of the DUT. The presser has a first press portion fixedly attached to a second press portion. The first press portion is configured to secure the DUT thereto, and the second press portion is connected to the thermal source. The guide frame has an outer frame, an inner frame, an opening formed by the inner frame, and guide holes formed in the outer frame. The first press portion extends through the opening, and the inner frame is secured between the first press portion and the second press portion. The first press portion is formed from a first material having a first thermal conductivity and a first coefficient of thermal expansion (CTE), the guide frame is formed from a second material having a second thermal conductivity and a second CTE, the second thermal conductivity is less than the first thermal conductivity, and the second CTE is less than the first CTE.

In some embodiments, the second press portion is formed from a third material having a third thermal conductivity and a third CTE, the second thermal conductivity is less than the third thermal conductivity, and the second CTE is less than the third CTE. In some embodiments, wherein the third material is the same as the first material.

In some embodiments, a first gap is between an inner frame sidewall and a first sidewall of the first press portion, a second gap is between a first outer frame sidewall and a second sidewall of the first press portion, and a third gap is between a second outer frame sidewall and a sidewall of the second press portion.

In some embodiments, the work press assembly further includes a first fiberglass layer and a second fiberglass layer. The inner frame is sandwiched between the first fiberglass layer and the second fiberglass layer, such that the first fiberglass layer separates the inner frame and the first press portion and the second fiberglass layer separates the inner frame and the second press portion. In some embodiments, the first press portion and the second press portion are configured to vacuum suction the DUT to the presser.

In some embodiments, the first press portion has a middle portion disposed between a top portion and a bottom portion. The top portion is disposed within the opening of the guide frame and connected to the second press portion. A gap is formed between the middle portion of the first press portion and the second press portion, and the inner frame partially fills the gap. In some embodiments, a width of the top portion is less than a width of the opening, a width of the middle portion is greater than the width of the opening, and a width of the second press portion is greater than the width of the opening. In some embodiments, the middle portion and the second press portion do not physically contact the outer frame of the guide frame.

An exemplary method for assembling a work press assembly of a test handler includes receiving a first portion and a second portion of a presser of the work press assembly. The first portion is formed of a first material having a first coefficient of thermal expansion (CTE) and the second portion is formed of a second material having a second CTE. The method further includes receiving a guide frame of the work press assembly. The guide frame has an opening therein, the guide frame is formed of a third material having a third CTE, and the third CTE is less than the first CTE and the second CTE. The method further includes positioning the guide frame between the first portion of the presser and the second portion of the presser. The method further includes aligning the opening of the guide frame, the first portion of the presser, and the second portion of the presser. The method further includes attaching the first portion of the presser and the second portion of the presser. The guide frame is sandwiched between the first portion of the presser and the second portion of the presser, and the first portion of the presser extends through the opening of the guide frame.

In some embodiments, the guide frame includes an inner frame and an outer frame, and the inner frame forms the opening. In such embodiments, the aligning can include aligning the first portion of the presser and the second portion of the presser with the inner frame of the guide frame, such that a first spacing is between the first portion of the presser and the outer frame of the guide frame, a second spacing is between the first portion of the presser and the inner frame of the guide frame, and a third spacing is between the second portion of the presser and the outer frame of the guide frame. In some embodiments, attaching the first portion of the presser and the second portion of the presser includes pushing the first portion of the presser and the second portion of the presser against opposite surfaces of the guide frame, wherein the opposite surfaces of the guide frame are formed by thermal insulation layers.

An exemplary method for fabricating a work press assembly of a test handler includes forming a first press portion and a second press portion of a presser of the work press assembly. The first press portion and the second press portion are formed of a first material having a first coefficient of thermal expansion (CTE). The method further includes forming a guide frame of the work press assembly. The guide frame can have an outer frame, an inner frame, an opening formed by the inner frame, and guide holes in the outer frame. The outer frame and the inner frame are formed of a second material having a second CTE, and the second CTE is less than the first CTE. The guide frame can further include one or more thermal insulation layers, such as fiberglass layers, disposed on the inner frame. The method further includes assembling the first press portion, the second press portion, and the guide frame, wherein the inner frame is sandwiched between the first press portion and the second press portion when assembled.