Integrated circuit (IC) chip test socket assembly with spring probes that scrub the electrical contact pads of the IC package

Abstract

In one aspect, a socket assembly for testing integrated circuits (ICs) in an IC package is provided. The socket assembly includes a body having a first surface and a second surface opposite the first surface, the body defining a cavity extending between the first and second surfaces. The cavity is dimensioned to receive a spring probe therein, and the body further defines an opening in the first surface for the cavity that is offset relative to a centerline of the cavity.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to Chinese Patent Application No. 202211201313.4, filed on September 29, 2022, entitled "Integrated Circuit (IC) Chip Test Socket Assembly with Spring Probes for Scrubing Electrical Contact Pads of an IC Package," the entire contents of which are incorporated herein by reference. [Technical Field]

[0002] The field of the invention relates to test sockets for integrated circuit packages, and more particularly to test sockets that utilize spring probes that contact substantially planar pads on the integrated circuit package. [Background technology]

[0003] An integrated circuit (IC) is a set of electronic circuits fabricated on a flat substate, or chip, of semiconductor material such as silicon. The fabrication of ICs generally includes testing the ICs in a manner that simulates the end-user's application of those ICs. One method of testing ICs is to connect each IC via a test socket assembly to a printed circuit board (PCB) or load board that exercises the IC's various functions. A test socket assembly can be used to test many ICs.

[0004] Land grid array (LGA) and quad flat no-lead packages (QFN) are two common packages for semiconductor ICs. LGA and QFN packages use substantially flat conductive pads on the bottom of the package that are electrically connected to the IC within the package (e.g., using wire bonds or other types of contact methods, such as flip-chip bonding the IC to the IC package's substrate). Test sockets for LGA and QFN packages typically include spring probes that contact pads on the underside of the IC package when the IC package is held in place within the test socket. However, oxidation of the pads on the IC package can cause poor electrical connection between the pads on the IC package and the spring probes in the test socket, distorting the results of tests performed on the IC within the IC package. Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, improved test sockets are desirable for more reliably testing IC packages that utilize substantially flat conductive pads, such as LGA and QFN packages. [Means for solving the problem]

[0006] In one aspect, a socket assembly for testing integrated circuits (ICs) in an IC package is provided. The socket assembly includes a body having a first surface and a second surface opposite the first surface, the body defining a cavity extending between the first and second surfaces. The cavity is dimensioned to receive a spring probe therein, and the body further defines an opening in the first surface for the cavity that is offset relative to a centerline of the cavity.

[0007] In another aspect, a method of assembling a socket assembly for testing integrated circuits (ICs) in an IC package is provided. The method includes forming a body including a first surface and a second surface opposite the first surface. The body defines a cavity extending between the first and second surfaces. The cavity is dimensioned to receive a spring probe therein, and the body further defines an opening in the first surface for the cavity that is offset relative to a centerline of the cavity.

[0008] In another aspect, a socket assembly for testing integrated circuits (ICs) in an integrated circuit (IC) package is provided. The socket assembly includes a plurality of spring probes and a body. Each of the plurality of spring probes includes a tapered portion and a contact tip. The body includes a first surface and a second surface opposite the first surface. The body defines a plurality of cavities extending between the first surface and the second surface, each of the plurality of cavities being dimensioned to receive one of the plurality of spring probes therein. The body further defines an offset hole in the first surface for each of the plurality of cavities, and the tapered portion and the contact tip for each of the plurality of spring probes extend through the offset hole away from the first surface. [Brief explanation of the drawings]

[0009] These and other features, aspects, and advantages of the present invention will be better understood upon reading the following detailed description in conjunction with the accompanying drawings, in which like characters represent like parts throughout.

[0010] [Figure 1] 1 illustrates a perspective view of an IC test system in an exemplary embodiment. [Figure 2] 2 illustrates a perspective view of a socket assembly for the IC test system of FIG. 1 in an exemplary embodiment. [Figure 3A]2A shows a cross-sectional view of a region of the socket assembly of FIG. 2 taken along cut line 2-2 in an exemplary embodiment. [Figure 3B] 2A shows a cross-sectional view of a region of the socket assembly of FIG. 2 taken along cut line 2-2 in an exemplary embodiment. [Figure 4A] 2 along cut line 2-2 in an exemplary embodiment. [Figure 4B] 2 along cut line 2-2 in an exemplary embodiment. [Figure 5] 1 illustrates a block diagram of another IC test system in an exemplary embodiment. [Figure 6] 1 illustrates a block diagram of another IC test system in an exemplary embodiment. [Figure 7] 1 shows a flowchart of a method for assembling a socket assembly for testing ICs in IC packages in an exemplary embodiment.

[0011] Unless otherwise indicated, the drawings provided herein are meant to illustrate features of embodiments of the present invention. These features are believed to be applicable in a wide variety of systems incorporating one or more embodiments of the present invention. As such, the drawings are not meant to include all conventional features known by those skilled in the art to be required to practice the embodiments disclosed herein. DETAILED DESCRIPTION OF THE INVENTION

[0012] In the following specification and claims, reference will be made to a number of terms which shall be defined to have the following meanings.

[0013] The singular forms "a," "a," and "the" include plural references unless the context clearly dictates otherwise.

[0014] "Optional" or "optionally" means that the subsequently described event or circumstance can occur, but need not occur, and that the description includes instances in which the event occurs and instances in which it does not occur.

[0015] As used throughout the specification and claims of this application, approximation terms can be used to modify any quantitative expression and may vary within acceptable limits that do not result in a change in the basic function to which the term relates. Thus, values ​​modified by terms such as "about," "approximately," and "substantially" are not limited to the exact value specified. In at least some instances, approximation terms may correspond to the precision of an instrument for measuring the value. Herein, throughout the specification and claims, range limitations may be combined and / or interchanged, and such ranges identify and include all subranges contained therein, unless the context or language dictates otherwise.

[0016] In IC testing, a fundamental component of a test system that enables IC testing is the IC package test socket assembly, which can be reused multiple times to test large numbers of ICs. The test socket assembly electrically and mechanically connects the IC package to a printed circuit board (PCB) or load board. The degree to which a test socket assembly can be reused is quantified by how many "cycles" it can withstand without degradation of performance, such as signal performance. Each time an IC package is inserted or placed into a test socket assembly is called a cycle. Generally, over many cycles, the electrical and mechanical properties of the test socket assembly's contacts and structure begin to deteriorate.

[0017] As previously mentioned, test sockets for IC packages that utilize substantially flat conductive pads may be unable to provide sufficient reliable electrical contact between the spring probes in the test socket and the pads on the IC package due to pad oxidation, which can distort test results and cause the IC under test to fail the test process for reasons outside of the performance of the actual IC itself.

[0018]

[0003] In embodiments described herein, a test socket assembly is described that includes a spring probe having a contact tip that contacts a pad on an IC package. When the IC package is inserted into the test socket assembly, the spring probe is compressed by the pad on the IC package, and the contact tip of the spring probe moves substantially parallel to or substantially transverse to a major plane of the pad. The movement of the contact tip of the spring probe polishes a portion of the pad on the IC package, thereby removing oxidation from the pad and ensuring a reliable electrical connection between the contact tip of the spring probe and the pad.

[0019] While movement of the contact tip of the spring probe substantially parallel to the major plane of the pad can be generated in many different ways, one embodiment describes a test socket assembly body defining a cavity with an offset hole, within which the spring probe is disposed. The top plunger of the spring probe in the cavity extends through the offset hole and away from the major surface of the body. When an IC package is inserted into the test socket, a pad on the IC package engages the contact tip on the spring probe, compressing the spring probe and reducing its length. The top plunger tapers from a position adjacent to the contact tip of the top plunger to a shoulder of the shell of the spring probe that abuts the offset hole in the cavity. When the top plunger is compressed by a pad on the IC package, the offset hole and taper in the top plunger generate lateral movement of the contact tip relative to the pad, which moves the contact tip of the top plunger across a portion of the pad on the IC package. This movement removes oxidation from the pad and exposes the conductive features of the pad to the contact tip of the spring probe.

[0020] FIG. 1 shows a perspective view of an IC test system 100 in an exemplary embodiment. In this embodiment, the IC test system 100 includes a socket assembly 102, a semiconductor IC package 104, and a PCB 106. The IC package 104 is the device to be tested. The IC package 104 may include any type of package that utilizes substantially flat electrical contact pads (e.g., an LGA package, a QFN package, etc.) along a major surface (e.g., the underside of the IC package). The pads may be formed of a variety of conductive materials, including, but not limited to, tin, copper, and / or gold, and alloys of tin, copper, and / or gold.

[0021] In this embodiment, PCB 106 includes test circuitry (not shown) that operates to perform tests on an IC (not shown) in IC package 104 while IC package 104 is loaded into opening 108 of socket assembly 102. Socket assembly 102 provides electrical and mechanical connections between IC package 104 and PCB 106. In this embodiment, IC test system 100 further includes a plurality of spring probes 110.

[0022] During assembly of socket assembly 102, spring probes 110 are placed into cavities (not shown) in socket assembly 102 exposed by openings 108, and spring probes 110 are used to establish electrical connections between pads of IC package 104 and PCB 106. Specifically, spring probes 110 may be connected to one or more grounds of PCB 106, one or more power supplies of PCB 106, and various signals generated by test circuitry (not shown) of PCB 106.

[0023] In operation, socket assembly 102 is mounted on PCB 106. To test IC package 104, IC package 104 is placed in opening 108 of socket assembly 102, and test circuitry on PCB 106 is operated to perform tests on the IC in IC package 104 using power, ground, and signals transmitted between pads on PCB 106 and IC package 104 via spring probes 110.

[0024] In this embodiment, the spring probe 110 includes a top plunger 112, a shell 113, a spring (not shown) within the shell 113, and a bottom plunger 114. A contact tip 116 is located at the distal end of the top plunger 112. The spring probe 110 is mounted within a cavity (not shown) within the socket assembly 102, the cavity being exposed by an opening 108, and the contact tip 116 contacts a conductive pad (not shown) within the IC package 104 when the IC package 104 is inserted into the opening 108. The spring probe 110 has a length 118 that decreases as a force 120 is applied to the contact tip 116 by a pad on the IC package 104. When a force 120 is applied to the contact tip 116, the length 118 of the spring probe 110 decreases as the top plunger 112 and shell 113 slide over the bottom plunger 114.

[0025] In this embodiment, the top plunger 112 includes a tapered portion 122 having a variable width along a portion of the length 118 of the spring probe. In particular, the tapered portion 122 has a width that decreases from a first position 124 adjacent the contact tip 116 to a second position 126 adjacent a shoulder 128 of the shell 113. When a force 120 is applied to the contact tip 116 of the top plunger 112, the length 118 of the spring probe 110 decreases. The tapered portion 122 of the top plunger 112 interacts with features that form a cavity (not shown) in the socket assembly 102, causing the contact tip 116 to move or bend a predetermined distance 130. Moving the contact tip 116 through the predetermined distance 130 polishes the pad on the IC package 104, removing oxidation and ensuring a reliable electrical connection between the spring probe 110 and the pad, as described in more detail below. 1 shows a particular configuration of the top plunger 112, shell 113, bottom plunger 114, tapered portion 122, and contact tip 116 for spring probe 110, in other embodiments, spring probe 110 may have other configurations. For example, tapered plunger structures can include single-moving plunger probes and dual-moving plunger probes.

[0026] 2 shows a perspective view of an exemplary embodiment of a socket assembly 102 for the IC test system 100 of FIG. 1. The socket assembly 102 in this embodiment includes a socket frame 202 that contacts the top cartridge 204 along a top surface 206 of the top cartridge 204. The socket frame 202 and the top cartridge 204 can be referred to as a body in some embodiments. In other embodiments, the top cartridge 204 is individually referred to as a body.

[0027] FIG. 2 also shows the spring probes 110 arranged within the opening 108 and extending partially into the opening 108 from the top surface 206 of the top cartridge 204. The socket frame 202 and / or the top cartridge 204 may be formed from a metal, including aluminum, magnesium, titanium, zirconium, copper, iron, or alloys thereof. A portion of the socket frame 202 may include an electrically non-conductive insulator, such as aluminum oxide. The insulating layer may be coated with a polytetrafluoroethylene (PTFE) coating. For example, the top surface 208 around the perimeter 210 of the socket assembly 102 and the sides of the socket frame 202 may include the insulator. In some embodiments, the socket frame 202 and the top cartridge 204 may be a single piece. When the socket frame 202 and the top cartridge 204 are a single piece, the combination may be referred to as a socket body. FIG. 2 also illustrates a region 212 of the opening 108 that includes a cavity for the spring probes 110, which will be described in more detail below.

[0028] 3A and 3B show cross-sectional views of region 212 of socket assembly 102 along section line 2-2 of FIG. 2 in an exemplary embodiment. In the embodiment of FIG. 3A, top cartridge 204 includes a bottom surface 302 opposite top surface 206 of top cartridge 204. Bottom cartridge 304 includes a top surface 306 that contacts bottom surface 302 of top cartridge 204. Bottom cartridge 304 further includes a bottom surface 308 opposite top surface 306 of bottom cartridge 304. Bottom cartridge 304 may be formed from a metal including aluminum, magnesium, titanium, zirconium, copper, iron, or an alloy thereof.

[0029] In the embodiment of FIG. 3A , the spring probe 110 is disposed within a cavity 310 that penetrates the thickness 312 of the top cartridge 204. The thickness 312 of the top cartridge is defined as the distance between the top surface 206 and the bottom surface 302 of the top cartridge 204. In some embodiments, the cavity 310 includes an insulating layer along an inner wall 314 that electrically insulates the spring probe 110 from the top cartridge 204. In other embodiments, the cavity 310 and the spring probe 110 do not include insulation. For example, if the spring probe 110 is used to couple a ground on the PCB 106 to the IC package 104, the spring probe 110 may not include insulation and instead may electrically couple the top cartridge 204 to ground when the socket assembly 102 is coupled to the PCB 106 (see FIG. 1 ). In some embodiments, the spring probe 110 includes insulation rather than the cavity 310. For example, if the spring probe 110 is used to transmit signals between the IC package 104 and the PCB 106, the spring probe 110 may include an insulator (not shown) that electrically insulates the spring probe 110 from the top cartridge 204. In other embodiments, neither the spring probe 110 nor the cavity 310 includes insulation when the top cartridge 204 is formed of an insulating plastic material.

[0030] In the embodiment of FIG. 3A , the bottom cartridge 304 defines a probe holder 316 that is aligned with the cavity 310 in the top cartridge 204. The probe holder 316 prevents the spring probes 110 from passing completely through the cavity 310 and out the bottom of the socket assembly 102. In the embodiment of FIG. 3A , the probe holder 316 is partially open along the bottom surface 308 of the bottom cartridge 304, allowing a portion 318 of the spring probes 110 to extend from and contact the PCB 106 when the socket assembly 102 is mounted to the PCB 106. In some embodiments, the bottom cartridge 304 may be referred to as a body probe cap. In some embodiments, the probe holder 316 and / or the spring probes 110 may include an insulator to prevent the spring probes 110 from electrically shorting with the bottom cartridge 304. In other embodiments, neither the spring probes 110 nor the probe holder 316 include insulation when the bottom cartridge 304 is formed of an insulating plastic material. Collectively, the top cartridge 204 and the bottom cartridge 304 may be referred to as socket cartridges in some embodiments.

[0031] In this embodiment, the top cartridge 204 defines an opening 320 in its top surface, through which the contact tip 116 of the top plunger 112 protrudes to contact a pad on the IC package 104 when the IC package 104 is inserted into the opening 108 (see FIG. 1 ) of the socket assembly 102. The opening 320 in this embodiment is offset relative to a centerline 322 of the cavity 310. In some embodiments, the opening 320 may be formed using an offset hole formed or drilled in the top surface 206 that extends from the top surface 206 to the cavity 310. The portion of the feature that forms the opening in the top cartridge 204 abuts the shoulder 128 of the shell 113, preventing the spring probe 110 from passing completely through the opening 320 in the top cartridge 204.

[0032] When a pad on the IC package 104 applies a force 120 to the spring probe 110, the length 118 of the spring probe 110 decreases, causing the outer surface 324 of the tapered portion 122 to slide along the contact surface 326 of the opening 320. The interaction of the outer surface 324 of the tapered portion 122 with the contact surface 326 of the opening 320 displaces the contact tip 116 a predefined distance 130 away from the centerline 322 of the cavity 310, scrubbing oxidation off the pad of the IC package 104 where the contact tip 116 makes contact with the pad.

[0033] 3B shows the top cartridge 204 with the spring probe 110 removed from the cavity 310. In this view, the top cartridge 204 defines a centerline 328 relative to the opening 320 that has an offset 330 from the centerline 322 of the cavity 310. When the spring probe 110 is compressed by force 120 (see FIG. 3A), the tapered portion 122 interacts with the contact surface 326 of the top cartridge 204 based on the offset 330 in the opening 320 relative to the centerline 322 of the cavity 310, displacing the contact tip 116 of the spring probe 110 a predefined distance 130.

[0034] 4A and 4B show cross-sectional views of region 214 of socket assembly 102 along cut line 2-2 in FIG. 2 in an exemplary embodiment. In the embodiment depicted in FIG. 4A, the features within top cartridge 204 that define opening 320 include an electrically insulating layer 402, which electrically insulates top cartridge 204 from spring probe 110, where tapered portion 122 of top plunger 112 extends through opening 320 and shoulder 128 of shell 113 abuts the features within the top cartridge that define the opening. In the embodiment of FIG. 4A, an electrically non-conductive ring 404 circumscribes outer surface 406 of shell 113 and contacts inner wall 314 of cavity 310. Both non-conductive ring 404 and insulating layer 402 operate to electrically insulate spring probe 110 from top cartridge 204 and bottom cartridge 304. In the embodiment depicted in FIG. 4B, the top cartridge 204 and the bottom cartridge 304 may be formed from metal, and the inner surfaces of the cavity 310 of the top cartridge 204 and the probe holder 316 of the bottom cartridge 304 include an electrically insulating layer 408, which electrically insulates the spring probes 110 (not shown in this figure) from the top cartridge 204 and the bottom cartridge 304.

[0035] To assemble the socket assembly 102, the spring probes 110 are inserted into the cavities 310 of the top cartridge 204, the bottom cartridge 304 is attached to the top cartridge 204, and the socket frame 202 is placed over the top cartridge 204 such that the openings 108 in the socket frame 202 expose the openings 320 in the cavities 310 and the contact tips 116 of the spring probes 110. The socket assembly 102 may then be mounted to the PCB 106, with the portions 318 of the spring probes 110 protruding from the bottom surface 308 of the bottom cartridge 304 contacting the PCB 106. When placed within the opening 108, the IC package 104 is electrically connected to the PCB 106 via the spring probe 110, which moves or deflects a predefined distance 130 based on the offset 330 and the tapered portion 122 as the pad of the IC package 104 applies a force 120 to compress the spring probe 110 along its length 118.

[0036] 5 is a block diagram of another IC test system 500 in an exemplary embodiment. In this embodiment, the IC test system 500 is used to test one or more ICs 502 contained within an IC package 504. The IC package 504 may include, for example, any of the different types of packages described above. The ICs 502 are electrically connected to pads 506 of the IC package 504, which may be substantially planar.

[0037] In this embodiment, IC test system 500 includes a PCB 508 that includes test circuitry 510. Test circuitry 510 includes any component, system, or device that performs functional tests on an IC 502. IC test system 500 further includes a socket assembly 512 that includes a socket frame 514 and a socket cartridge 516. Socket frame 514 includes any component, system, or device that defines an opening 518 that receives an IC package 504 for testing. Socket cartridge 516 includes any component, system, or device that defines a cavity 520 having an offset opening 522 exposed by opening 518 in socket frame 514. Cavity 520 includes spring probes 524 that extend partially through offset opening 522. When IC package 504 is inserted into opening 518 in socket frame 514, spring probes 524 electrically connect IC 502 to test circuitry 510 via pads 506 and contact tips 526 of spring probes 524. The offset openings 522 interact with the spring probes 524 to partially scrub the pads 506 when the IC package 504 is inserted into the openings 518 of the socket frame 514. In this regard, the spring probes 524 and / or the offset openings 522 may include any feature or combination of features that displace the contact tips 526 substantially perpendicular to the direction of compression of the spring probes 524, thereby resulting in, for example, substantially lateral movement of the contact tips 526 along the planar surface of the pads 506. In some embodiments, the socket cartridge 516 includes:

[0038] 6 is a block diagram of another IC test system 600 in an exemplary embodiment. In this embodiment, the IC test system 600 is used to test one or more ICs 602 contained within an IC package 604. The IC package 604 may include, for example, any of the different types of packages described above. The ICs 602 are electrically connected to pads 606 of the IC package 604, which may be substantially planar.

[0039] In this embodiment, IC test system 600 includes a PCB 608 that includes test circuitry 610. Test circuitry 610 includes any component, system, or device that performs functional testing on an IC 602. IC test system 600 further includes a socket assembly 612 that includes a socket body 614, a spring probe 616, and a socket body probe cap 618. Socket body 614 includes any component, system, or device that defines an opening 620 that receives an IC package 604 for testing. Socket body 614 also includes any component, system, or device that defines a cavity 622 having an offset opening 624 exposed by opening 620 in socket body 614. Cavity 622 includes spring probe 616 that extends partially through offset opening 624. The spring probe 616 electrically connects the IC 602 to the test circuit 610 via the pad 606 and the contact tip 626 of the spring probe 616 when the IC package 604 is inserted into the opening 620 of the socket body 614. The offset opening 624 interacts with the spring probe 616 to partially scrub the pad 606 when the IC package 604 is inserted into the opening 620 of the socket body 614. In this regard, the spring probe 616 and / or the offset opening 624 may include any feature or combination of features that displaces the contact tip 626 substantially perpendicular to the direction of compression of the spring probe 616, thereby, for example, resulting in movement of the contact tip 626 substantially laterally along the planar surface of the pad 606. In this embodiment, the socket body probe cap 618 secures the spring probe 616 in place when the spring probe 616 is inserted into the cavity 622.

[0040] FIG. 7 shows a flowchart of a method 700 for assembling a socket assembly for testing ICs in IC packages in an exemplary embodiment. The method 700 begins by forming (702) a body including a first surface and a second surface opposite the first surface, the body defining a cavity extending between the first and second surfaces. The cavity is dimensioned to receive a spring probe, and the body further defines an opening for the cavity in the first surface that is offset relative to a centerline of the cavity. For example, with reference to FIG. 3A , the top cartridge 204 includes a cavity 310, and an opening 320 in the top surface 206 of the top cartridge 204 is offset relative to a centerline 322 of the cavity 310.

[0041] The method 700 continues by placing (704) a spring probe in the cavity, where the spring probe includes a tapered portion and a contact tip that extend away from the cavity and through an opening. For example, with reference to FIG. 3A , the spring probe 110 is placed in the cavity 310, with the tapered portion 122, probe retainer, and contact tip 116 of the spring probe 110 extending away from the cavity 310 and through the opening 320.

[0042] The method 700 continues by forming a body probe cap (706). The body probe cap includes a third surface and a fourth surface opposite the third surface. The third surface is configured to contact the second surface of the body, and the body probe cap includes a probe holder extending between the third and fourth surfaces. The probe holder is dimensioned to align with the cavity and expose a portion of the spring probe 110 at the fourth surface. For example, with reference to FIG. 3A , a bottom cartridge 304 is formed. The bottom cartridge includes a top surface 306 and a bottom surface 308, and a probe holder 316. The probe holder 316 is aligned with the cavity 310 and sized to expose a portion 318 of the spring probe 110 at the bottom surface 308.

[0043] The method 700 continues by mounting the body probe cap to the body (708). For example, with reference to FIG. 3A, the bottom cartridge 304 is mounted to the top cartridge 204, with the bottom cartridge 304 securing the spring probe 110 within the cavity 310 while exposing the portion 318 at the bottom surface 308.

[0044] In some embodiments, the method 700 forms the body by forming a through-hole for the opening in a first surface of the body that is offset relative to a centerline of the cavity. For example, with reference to FIG. 3B , the top cartridge 204 includes a cavity 310, and the opening 320 (in some embodiments, a through-hole) in the top surface 206 of the top cartridge 204 has an offset 330 relative to a centerline 322 of the cavity 310.

[0045] In some embodiments, the body defines a contact surface between the opening disposed in the cavity and the spring probe, and method 700 continues by forming an electrically insulating material on the contact surface of the opening that electrically insulates the spring probe from the body. For example, with reference to FIG. 4A , insulating layer 402 is formed on contact surface 326 of opening 320. In another example, with reference to FIG. 4B , insulating layer 408 is formed on the cavity 310 and the interior surface of probe holder 316.

[0046] In some embodiments, the method 700 forms the body by defining a contact surface between the opening and the tapered portion of the spring probe that laterally displaces the contact tip relative to the first and second surfaces when the spring probe is compressed in length. For example, with reference to FIG. 3A , the contact surface 326 within the opening 320 defined by the top cartridge 204 interacts with the tapered portion 122 of the spring probe 110, displacing the contact tip 116 laterally relative to the top surface 206 of the top cartridge 204 when the spring probe 110 is compressed in length 118. When the spring probe 110 is compressed in length 118, the contact tip 116 moves a predefined distance 130.

[0047] In some embodiments, method 700 forms the body by forming a socket frame defining an opening dimensioned to receive the IC package. In this embodiment, method 700 continues by forming a cartridge defining a cavity, and mounting the socket frame to the top cartridge by covering a portion of the top cartridge and exposing the cavity at the opening. For example, with reference to FIGS. 2 and 3A and 3B, socket frame 202 is formed (see FIG. 2), and top cartridge 204 defining cavity 310 is formed (see FIGS. 3A and 3B). Socket frame 202 is mounted to top cartridge 204 (see FIG. 2).

[0048] Examples of technical effects of the apparatus and methods described herein include one or more of: (a) ensuring a reliable electrical connection between the spring probes and the test pads by scrubbing the pads when the IC package is inserted into the test socket; and (b) preventing false test fails due to oxidation on the pads of the IC package.

[0049] Although specific features of various embodiments of the invention may be shown in some drawings and not in others, this is for convenience only, and in accordance with the principles of the invention, any feature of a drawing may be referenced and / or claimed in combination with any feature of any other drawing.

[0050] This written description uses examples to disclose embodiments, including the best mode, and also to enable any person skilled in the art to practice the embodiments, including making and using any devices or systems and practicing any integration methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have elements that do not differ from the literal language of the claims, or if they include equivalent elements that do not differ from the literal language of the claims.

Claims

1. 1. A socket assembly for testing an integrated circuit (IC) in an IC package, the socket assembly comprising:

1. A socket assembly comprising: a body having a first surface and a second surface opposite the first surface, the body defining a cavity extending between the first surface and the second surface, the cavity dimensioned to receive a spring probe therein, the body further defining an opening in the first surface for the cavity offset relative to a centerline of the cavity.

2. The socket assembly of claim 1 , wherein the opening is defined by a through hole in the first surface of the body that is offset relative to a centerline of the cavity.

3. the body defines a contact surface between the opening and a spring probe disposed within the cavity; 2. The socket assembly of claim 1, wherein said body includes an electrically insulating layer on said contact surface that electrically insulates said spring probe from said body.

4. a spring probe partially disposed within the cavity, the spring probe including a tapered portion and a contact tip extending away from the cavity through the opening; The socket assembly of claim 3 , further comprising an electrically non-conductive ring in contact with an inner wall of the cavity and circumscribing an outer surface of the spring probe.

5. 2. The socket assembly of claim 1, further comprising: a spring probe partially disposed within the cavity, the spring probe comprising a tapered portion and a contact tip extending through the opening away from the cavity.

6. 6. The socket assembly of claim 5, wherein the body defines a contact surface between the opening and the tapered portion of the spring probe, the contact surface configured to laterally displace the contact tip relative to the first surface when the spring probe is longitudinally compressed.

7. the body includes a socket frame and a top cartridge that define the cavity; the socket frame defines an opening sized to receive the IC package; The socket assembly of claim 1 , wherein the socket frame is configured to cover a portion of the top cartridge and expose the cavity at the opening.

8. a body probe cap having a third surface and a fourth surface opposite the third surface, the third surface configured to contact the second surface of the body; 2. The socket assembly of claim 1, wherein the body probe cap further comprises a probe holder extending between the third surface and the fourth surface, the probe holder being aligned with the cavity and dimensioned to expose a portion of the spring probe at the fourth surface.

9. 1. A method of assembling a socket assembly for testing an integrated circuit (IC) in an IC package, the method comprising:

1. A method comprising: forming a body having a first surface and a second surface opposite the first surface, the body defining a cavity extending between the first surface and the second surface, the cavity being dimensioned to receive a spring probe therein, the body further defining an opening in the first surface for the cavity offset relative to a centerline of the cavity.

10. The step of forming the body further comprises:

10. The method of claim 9, further comprising forming a through hole for the opening in the first surface of the body offset relative to the centerline of the cavity.

11. the body defining a contact surface between the opening and a spring probe disposed within the cavity; 10. The method of claim 9, further comprising forming an electrically insulating layer on the contact surface that electrically insulates the spring probe from the body.

12. The method further comprises:

10. The method of claim 9, further comprising: placing a spring probe partially disposed within the cavity, the spring probe having a tapered portion and a contact tip extending through the opening away from the cavity.

13. The step of forming the body further comprises:

13. The method of claim 12, further comprising: defining a contact surface between the opening and the tapered portion of the spring probe, the contact surface configured to displace the contact tip laterally relative to the first surface when the spring probe is compressed longitudinally.

14. The step of forming the body further comprises: forming a socket frame defining an opening dimensioned to receive the IC package; forming a top cartridge defining said cavity; and mounting the socket frame to the top cartridge by covering a portion of the top cartridge and exposing the cavity at the opening.

15. forming a body probe cap having a third surface and a fourth surface opposite the third surface; 10. The method of claim 9, wherein the third surface is configured to contact the second surface of the body, and the body probe cap further comprises a probe holder extending between the third surface and the fourth surface, the probe holder being aligned with the cavity and dimensioned to expose a portion of a spring probe at the fourth surface.

16. 1. A socket assembly for testing an integrated circuit (IC) in an IC package, the socket assembly comprising: a plurality of spring probes, each having a tapered portion and a contact tip; a body having a first surface and a second surface opposite the first surface, the body defining a plurality of cavities extending between the first surface and the second surface, each of the plurality of cavities dimensioned to receive one of the plurality of spring probes therein, the body further defining an offset hole in the first surface for each of the plurality of cavities, the tapered portion and the contact tip for each of the plurality of spring probes extending away from the first surface through the offset hole.

17. 17. The socket assembly of claim 16, wherein when the plurality of spring probes are compressed, contact between the tapered portion and the contact surface of the offset hole displaces the contact tip laterally relative to a major plane of the first surface.

18. 18. The socket assembly of claim 17, wherein said body includes an electrically insulating layer on said contact surface that electrically insulates said plurality of spring probes from said body.

19. the body includes a socket frame and a top cartridge defining the plurality of cavities; the socket frame defines an opening dimensioned to receive the IC package; 17. The socket assembly of claim 16, wherein the socket frame is configured to cover a portion of the top cartridge and expose the plurality of cavities at the opening.

20. a main probe cap having a third surface and a fourth surface opposite the third surface; 17. The socket assembly of claim 16, wherein the third surface is configured to contact the second surface of the body, and the body probe cap further comprises a plurality of probe holders extending between the third surface and the fourth surface, each of the plurality of probe holders being aligned with one of the plurality of cavities and dimensioned to expose a portion of one of the plurality of spring probes at the fourth surface.

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