Modular low-level contact resistance testing device for processor socket

Abstract

A modular low level contact resistance test device for a processor socket. A low level contact resistance (LLCR) test device includes a test board, an interface board, and a terminal board. The test board comprises a processor socket. The interface board is connected to both the test board and the terminal board. The terminal block is connected to the contact resistance tester. An LLCR system including an LLCR test device and a contact resistance tester may be portable. The test board can adapt to thermal management solutions of different sizes and types. Different test board designs can accommodate different socket processor configurations, and different test boards can be easily housed by the LLCR test device due to their modular design.

Description

Background Art

[0001] Low-level contact resistance (LLCR) metrology is an important capability for qualifying processor socket designs and analyzing processor stack loading mechanisms. LLCR metrology refers to the measurement of the resistance at the contact interface between two materials at low current and low voltage levels. The current and voltage levels used for LLCR measurements are low enough so as not to damage thin films (such as oxide layers) that may be present at the contact interface. Brief Description of the Drawings

[0002] Figure 1A-1B Are a top view and a cross-sectional view, respectively, of an example processor stack to a socket.

[0003] Figure 2 Is a perspective view of an example LLCR test apparatus.

[0004] Figure 3 Is an example LLCR test method.

[0005] Figure 4 Is a block diagram of an example computing system that can perform LLCR measurements.

[0006] Figure 5 Is a block diagram of an example processor unit that executes computer-executable instructions as part of implementing the techniques described herein. Detailed Description

[0007] LLCR metrology is an important capability during socket design because it allows for the measurement of the resistance at the points where the processor contacts the socket. Minimizing the processor-to-socket contact resistance is desirable because when current passes through an individual processor-socket connection, it can cause voltage drops and heat generation. In high-power processors where individual processor pins or pads can draw large amounts of current, an undesirably high level of contact resistance can cause large enough voltage drops and / or heat generation to cause the processor not to perform as expected.

[0008] Existing LLCR measurement devices can have various limitations. First, they can be large and bulky, which can make them inconvenient to use due to their lack of portability. For an organization that has multiple socket designs under development at any given time, this can result in long turn-around LLCR measurement times because the socket design to be tested must be taken to where the LLCR measurement device is located, rather than the other way around. Second, wire connection issues to the socket for measurement can cause incorrect measurements. In some existing LLCR measurement devices, wire connection issues can falsely indicate what percentage of the socket processor contacts are electrically open, which can be on the order of hundreds of connections in a high-end server processor with thousands of pins. Third, existing LLCR devices may not be physically able to accommodate a socket filled with a large thermal management solution. To test a socket filled with a processor attached to a large thermal management solution, physical changes to the thermal management solution may be required. In some cases, this can involve cutting off one or more parts of the thermal management solution.

[0009] Figure 1A-1B Are a top view and a cross-sectional view, respectively, of an example processor stack attached to a socket. Figure 1B Is taken along line A-A’ Figure 1A Cross-sectional view of the processor stack 100. The processor stack 100 includes integrated circuit components 104 and a main heat sink 108 attached to the integrated circuit components 104 via a thermal interface material (TIM) layer 112. A heat pipe 114 attached to the main heat sink 108 at one end and to a secondary heat sink 118 at a second end provides transfer of heat from the main heat sink 108 to the secondary heat sink 118. The main heat sink 108 and the secondary heat sink 118 include a plurality of fins. The processor stack 100 is attached to a socket 116, which in turn is attached to a printed circuit board 120. The printed circuit board can be part of a device for LLCR measurement.

[0010] Due to the shape of the heat pipe 114 and the position, size, and orientation of the secondary heat sink 118 relative to the main heat sink 108, Figure 1A-1B The thermal management solution illustrated in can be considered to have an “outrigger” configuration. In addition to the heat exchanger attached to the integrated circuit component, in cases where there is more physical volume available in the computing system for additional heat exchangers (e.g., heat sinks), a thermal management solution of the type shown in Figure 1A-1B Can be utilized. In some embodiments, a thermal management solution that includes a main heat sink, a heat pipe, and a secondary heat sink and has the Figure 1A-1B “Outrigger” configuration illustrated in can be An extended volume air cooling (EVAC) thermal management solution.

[0011] The printed circuit board 120 includes alignment holes 124 that receive alignment pins of the LLCR test device. The alignment pins are used to position the printed circuit board 120 during LLCR testing. As can be seen, the two alignment holes 124 overlap with the secondary heat sink 118. Thus, attempting to place the printed circuit board 120 in an LLCR test device having alignment pins corresponding to the alignment holes 124 will be unsuccessful because the secondary heat sink 118 will interfere with the alignment pins extending fully through the alignment holes 124. A solution to this problem can include cutting the heat pipe 114 at a point between the primary heat sink 108 and the secondary heat sink 118 or cutting off the end of the secondary heat sink 118 to allow the LLCR tester alignment pins to extend fully through the alignment holes 124. Such a change to the thermal management solution to accommodate the LLCR tester limitation may be undesirable because a processor stack with a pure thermal management solution may be desired for additional testing of the processor stack and for preventing reuse of the thermal management solution.

[0012] This document describes techniques related to the LLCR testing of a processor inserted into a socket. The disclosed LLCR testing apparatus includes a test board that includes an attached socket to which a processor can be attached, and for which it is desired to determine the processor-socket contact resistance of the attached socket. The LLCR testing apparatus further includes a patchboard connected to a contact resistance tester and an interface board connected to both the test board and the patchboard. The LLCR testing apparatus is modular in that the test board, interface board, and patchboard are releasably connectable. This allows for simple and rapid reconfiguration of the testing apparatus to test different socket-processor configurations. The patchboard can include a flexible printed circuit board and thus allows for flexibility in how the interface board and test board are oriented relative to the contact resistance tester during LLCR testing. For example, if the test surface of the contact resistance tester lies in the x-y plane, the interface board and test board can lie in the y-z plane, or be oriented in any non-parallel manner relative to the test surface. The testing apparatus can be smaller than existing LLCR testers and can be used with a small form factor contact resistance tester, which in some cases can roughly be the size of a laptop computer. For example, while some existing LLCR testers are approximately five feet tall and have a length and width of approximately two feet, in some embodiments, the LLCR testing apparatus disclosed herein can be approximately two feet in length, approximately 1.3 feet in width, and approximately 0.3 feet in height. Thus, the overall LLCR testing system including the testing apparatus disclosed herein is portable. The LLCR testing apparatus disclosed herein can also allow for testing of processors with large attached thermal management solutions. Thus, the LLCR testing techniques described herein can at least have the advantages of being modular, portable, and allowing for large thermal management solutions. Additionally, since the test, interface, and patch interface boards are directly connected, the LLCR testing apparatus can have the additional advantage of being less susceptible to wire connection problems that can result in false open circuit reports.

[0013] In the following description, specific details are set forth, but embodiments of the techniques described herein can also be practiced without these specific details. Well-known circuits, structures, and techniques are not shown in detail to avoid obscuring the understanding of this description. Phrases such as "embodiment", "various embodiments", "some embodiments", and the like can include features, structures, or characteristics, but not every embodiment necessarily includes the specific features, structures, or characteristics.

[0014] Some embodiments may have some, all of the features described for other embodiments, or may not have the features described for other embodiments. "First", "Second", "Third", and the like describe common objects and indicate different instances of the same object being referred to. Such adjectives do not imply that the objects so described must be in a given sequence in time or space, in rank, or in any other way. "Connected" may indicate that elements are in direct physical or electrical contact with each other, and "coupled" may indicate that elements cooperate or interact with each other, but they may or may not be in direct physical or electrical contact. Additionally, terms such as "comprising", "including", "having", and the like as used with respect to embodiments of the present disclosure are synonymous.

[0015] In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding thereof. However, it will be apparent that novel embodiments may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate the description thereof. The intention is to cover all modifications, equivalents, and alternatives falling within the scope of the claims.

[0016] As used herein, the phrase "located on" in the context of a first layer or component located on a second layer or component means that the first layer or component is directly physically attached to the second part or component (with no layer or component between the first and second layers or components) or is physically attached to the second layer or component using one or more intervening layers or components.

[0017] As used herein, the term "integrated circuit component" refers to an integrated circuit product, either packaged or unpackaged. A packaged integrated circuit component includes one or more integrated circuit dies mounted on a package substrate, where the integrated circuit die and the package substrate are encapsulated in a housing material such as metal, plastic, glass, or ceramic. The integrated circuit die may include one or more transistors, support circuitry for routing electrical signals to the transistors, passive components (e.g., signal traces, resistors, capacitors, or inductors), and / or any other integrated circuit components. In one example of an integrated circuit component, the packaged integrated circuit component contains one or more processor units mounted on a substrate, where the outer surface of the substrate includes a pin grid array (PGA). In one example of an unpackaged integrated circuit component, a single monolithic integrated circuit die includes solder bumps attached to contacts on the die. The solder bumps allow the die to be directly attached to a printed circuit board. The integrated circuit component may include one or more of any of the computing system components described or referenced herein or any other computing system components, such as processor units (e.g., system on a chip (SoC), processor core, graphics processing unit (GPU), accelerator, chipset processor), I / O controllers, memory, or network interface controllers.

[0018] As used herein, the terms "operate", "execute", or "run" are used interchangeably when they relate to software or firmware associated with a system, device, platform, or resource and can refer to software or firmware stored on one or more computer-readable storage media accessible by the system, device, platform, or resource, even if the software or firmware instructions are not actively executed by the system, device, platform, or resource.

[0019] As used herein, the term "coupling component" refers to a structure that conductively and / or mechanically couples two components, such as two printed circuit boards, a socket and a printed circuit board, or an integrated circuit component and a socket. The term coupling component can refer to a pad (also referred to as a contact pad or bonding pad), a pin (such as a pogo pin), a hole (e.g., that can receive a pin), or other suitable structures such as solder balls.

[0020] As used herein, the phrase "conductively coupled" refers to layers or components that are coupled to facilitate the flow of current between them. For example, a coupling component located on a first surface of a printed circuit board can be conductively coupled to a coupling component located on a second surface of the printed circuit board through conductive traces and vias, where the vias act as interconnections between conductive traces on different metal layers of the printed circuit board.

[0021] Reference is now made to the drawings, which are not necessarily to scale, where like or identical numerals may be used to specify like or corresponding parts in different figures. The use of like or identical numerals in different figures does not imply that all figures including those like or identical numerals constitute a single or identical embodiment. Identical numerals with different letter suffixes can represent different instances of like components. The drawings generally illustrate, by way of example and not limitation, various embodiments discussed in this document.

[0022] Figure 2 is a perspective view of an exemplary LLCR test apparatus. The test apparatus 200 includes a test board 204, an interface board 208, and a wiring board 212. The test apparatus 200 is connected to a contact resistance tester 216. When connected, the test apparatus 200 and the contact resistance tester 216 can measure the resistance of contacts between integrated circuit components attached to a socket on the test board 204. The LLCR test apparatus 200 is modular because the test board 204, the interface board 208, the wiring board 212, and the contact resistance tester 216 are all releasably connectable.

[0023] The test board 204 includes a printed circuit board 206 and a socket 209. The loading of the test board 204 lies in attaching the processor stack 210 to the socket 209. The processor stack 210 includes integrated circuit components (not shown) attached to a thermal management solution 214 through a layer of thermal interface material (not shown). The integrated circuit components are connected to the socket 209. The socket 209 can be any type of socket to which the integrated circuit components can be attached, such as a PGA (Pin Grid Array), LGA (Land Grid Array), or BGA (Ball Grid Array) socket. Thus, the integrated circuit component-socket contact to be tested by the contact resistance tester 216 can include the contact between the coupling components (e.g., pins, socket balls) on the surface of the integrated circuit components and the coupling components (e.g., pads, holes) on the surface of the socket. For example, the integrated circuit component-socket contact to be tested by the contact resistance tester 216 can include the contact between the integrated circuit component pins and the socket holes (e.g., in the case of a PGA socket), the integrated circuit component pads and the socket pins (e.g., in the case of an LGA socket), or the integrated circuit component solder balls and the socket pads (e.g., in the case of a BGA socket). The test board 204 further includes a stiffener board (not shown) positioned on the bottom surface 224 of the test board 204 to add structural support to the test board 204 near the socket 209. In other test board embodiments, no stiffener board is used.

[0024] The printed circuit board 206 and any other printed circuit board described or referenced herein include a plurality of metal (or interconnect) layers separated from each other by layers of dielectric material (e.g., FR-4 or other glass fiber-reinforced epoxy laminates) and interconnected by conductive vias. Each metal layer includes conductive traces. Any one or more of the metal layers can be formed in a desired circuit pattern to route electrical signals between components attached or connected to the printed circuit board.

[0025] The thermal management solution 214 is similar to Figure 1A-1B the outrigger bracket thermal management solution illustrated in Figure 2 and includes a main heat sink 218, a secondary heat sink 220, and heat pipes 217 attached to the integrated circuit components via a layer of thermal interface material. Individual heat pipes 217 are attached to one of the secondary heat sinks 220 and the main heat sink 218 and transfer heat from the main heat sink 218 to one of the secondary heat sinks 220. In other embodiments, the thermal management solution attached to the integrated circuit components to be tested can include Figure 2 any suitable variation of the thermal management solution illustrated in Figure 2The solid main heat sink 218 and the second heat sink 220 illustrated in the figure. In other embodiments, the thermal management solution may include a cold plate or a vapor chamber, a thermal management solution in which the cold plate or the vapor chamber is part of a closed-loop liquid cooling system (which may further include a heat exchanger, a pump, and one or more pipes connecting the heat exchanger to the cold plate or the vapor chamber), or an immersion-based liquid cooling thermal management solution, in which the thermal management solution attached to the processing unit is at least partially submerged in a dielectric liquid during the contact resistance test. Thermal management solutions of different sizes can also be accommodated, such as solutions having a height with multiple rackmount units (e.g., 1U, 2U) or thermal management solutions having a longer length, such as Figure 1A-1B the thermal management solution illustrated in the figure. Thermal management solutions of different sizes can be accommodated by a single test board design or different test board designs, which are individually customized to the size of a particular thermal management solution.

[0026] The printed circuit board 206 includes a first plurality of coupling components (not shown) on the top surface 222 of the printed circuit board 206 and a second plurality of coupling components (not shown) on the bottom surface 224 of the printed circuit board 206. The first plurality of coupling components are connected to the socket 209. Conductive traces and vias in the printed circuit board 206 conductively couple the first set of coupling components on the top surface 222 to the second set of coupling components on the bottom surface 224 of the printed circuit board 206.

[0027] The interface board 208 includes a printed circuit board 244, which includes a first plurality of coupling components 228, a second plurality of coupling components, and a cutout 230. The interface board 208 translates the footprint of the coupling components 236 on the top surface 246 of the wiring board 212 into the footprint of the coupling components on the bottom surface 224 of the test board 204. The first plurality of coupling components 228 are located on the top surface 242 of the printed circuit board 244 and enable the interface board 208 to connect to the test board 204, and the second plurality of coupling components are located on the bottom surface 232 of the printed circuit board 244 and enable the interface board 208 to connect to the wiring board 212. The first plurality of coupling components 228 are grouped into eight connector blocks, each of which includes a plurality of coupling components. The eight connector blocks are connected to corresponding connector blocks (each of which includes a plurality of coupling components) on the bottom surface 224 of the test board 204. In other interface board embodiments, the first plurality of coupling components 228 on the printed circuit board 244 may take a configuration that does not include coupling components grouped into connector blocks. The cutout 230 is used to accommodate a reinforcement plate located on the bottom surface 224 of the test board 204. In an LLCR test device embodiment where the test board does not have a reinforcement plate, the interface board may not include a cutout. The second plurality of coupling components are located in a region of the bottom surface 232 of the interface board 208 opposite the reinforcement plate 234. In some LLCR test device embodiments, the interface board does not include a reinforcement plate in the region of the interface board where the plurality of coupling components that connect to the contact resistance tester are located. The first plurality of coupling components 228 are conductively coupled to the second plurality of coupling components through conductive traces and vias in the printed circuit board 244. In some embodiments, the printed circuit board 244 is approximately 62 mils thick and has ten metal layers. In other embodiments, the printed circuit board 244 may have a different thickness and / or include a different number of metal layers.

[0028] The contact resistance tester 216 can be any tester capable of performing LLCR measurements, such as a four-wire Kelvin measurement tool. In some embodiments, the contact resistance tester 216 can be a commercially available contact resistance tester. The contact resistance tester 216 includes a plurality of coupling components 250, to which the second plurality of coupling components 238 of the wiring board 212 are connected during contact resistance testing. The plurality of coupling components 250 are located on a test surface 252, which is located within a recess 254 of the contact resistance tester 216. The contact resistance tester 216 can be portable because it is small and light enough to be carried by a person and can be easily connected to a nearby computing system such as a laptop computer in a wired or wireless manner.

[0029] The LLCR test apparatus disclosed herein contemplates measuring the contact resistance of sockets having areas, lengths, and / or widths that can exceed the area, length, and / or width of the test surface of a contact resistance tester. In other words, the LLCR test apparatus converts the coverage area of a coupling component on the test surface of a contact resistance tester to the coverage area of the coupling component on a test board connected to the socket. For example, a socket having a length and width greater than the width of the test surface of some existing commercial contact resistance testers (which can be approximately 110 millimeters for some contact resistance testers) can be accommodated by the LLCR test apparatus disclosed herein. As socket sizes continue to grow, new test boards (and possibly also new interface boards) can be designed to work with existing contact resistance testers.

[0030] The wiring board 212 includes a printed circuit board 248 that includes a first plurality of coupling components 236 and a second plurality of coupling components 238. The first plurality of coupling components 236 are located on the top surface 246 of the printed circuit board 248 and enable the wiring board 212 to be connected to the interface board 208, and the second plurality of coupling components 238 are located on the bottom surface 240 of the printed circuit board 248 and enable the wiring board 212 to be connected to a plurality of coupling components 250 on the test surface 252 of the contact resistance tester 216. The first and second pluralities of coupling components 236 and 238 are illustrated as pins, but can be other coupling components in other embodiments. The first plurality of coupling components 236 are conductively coupled to the second plurality of coupling components 238 through conductive traces and vias in the printed circuit board 248. In some embodiments, the printed circuit board 248 is approximately 20 mils thick and includes four or more metal layers. In other embodiments, the printed circuit board 248 can have a different thickness and / or include a different number of metal layers.

[0031] The wiring board 212 acts as a bridge that allows the interface board 208 to be conductively coupled to the contact resistance tester 216. That is, the width and length of the wiring board 212 are less than the width and length of the recess such that the wiring board 212 fits within the recess. The wiring board further has a height greater than the depth of the recess. This allows the wiring board to effectively provide the transformation of the coupling components 250 of the contact resistance tester 216 to a point above the top surface of the contact resistance tester 216 in the z direction.

[0032] In such as in Figure 2In some embodiments, such as the embodiments illustrated in the figures, the wiring board 212 is rigid. In other embodiments, the wiring board includes a flexible printed circuit board and is at least partially flexible. A wiring board that includes a flexible printed circuit board can enable a degree of freedom of movement of the interface board and the test board relative to the contact resistance tester. This can allow for convenient positioning of the interface and test boards during testing, as compared to embodiments of an LLCR test apparatus where the interface and test boards are fixed relative to the contact resistance tester due to the LLCR test apparatus including a rigid wiring board.

[0033] In other embodiments, the wiring board includes a flexible printed circuit board that extends a certain distance, such as six inches, one foot, two feet, or other suitable distance, which can allow for even greater flexibility in positioning the LLCR test apparatus. For example, in such an embodiment, when manipulating the interface and test boards during testing (such as when replacing the test board with different socket-processor configurations), the contact resistance tester can remain in a stationary position. A wiring board with a flexible printed circuit board that extends a certain distance can also enable testing of processor stacks with thermal management solutions that cannot be tested using existing LLCR testers. For example, contact resistance measurements of a socket-processor stack configuration with a bath-based liquid cooling thermal management solution can be performed by at least partially submerging the thermal management solution in a dielectric liquid, where the flexible printed circuit board extends from the interface board to the contact resistance tester positioned away from the container containing the dielectric liquid.

[0034] Embodiments of the portable LLCR test apparatus disclosed herein can allow for flexible LLCR testing in organizations where multiple socket designs may be developed simultaneously, by allowing for the use of multiple LLCR test systems to be deployed at the test laboratories of the organization across customer sites for testing and debugging, rather than requiring that socket prototypes or sockets that have failed in the field be brought to the location of the existing LLCR tester. Portability can be important for LLCR testing of LGA sockets because LGA LLCR measurements can be sensitive to handling vibrations. Handling of a loaded LGA socket, which can involve transporting the loaded LGA socket from the socket development laboratory to the LLCR test laboratory, can cause sufficient wear of the oxide layer at the contacts of the socket integrated circuit components, resulting in an LLCR measurement change of more than an order of magnitude in the LGA LLCR measurement relative to a loaded LGA socket that has not been subjected to handling vibrations. Thus, by being able to bring the LLCR test solution to the test laboratory rather than bringing the prototype socket integrated circuit component configuration to the LLCR tester, the portable LLCR test technology disclosed herein can reduce handling-induced LLCR measurement errors.

[0035] In addition to being portable, the embodiments of the LLCR test apparatus disclosed herein can accommodate measurements of processor stack-socket configurations with thermal management solutions that are larger than those that can be accommodated by existing LLCR testers. That is, thermal management solutions that require physical changes (e.g., as described above, by cutting off the ends of heat pipes or secondary heat sinks) to be tested by some existing LLCR testers may not need to be changed to be tested by an LLCR test system that includes any of the LLCR test apparatuses disclosed herein.

[0036] The modularity of the LLCR test apparatuses disclosed herein can accommodate easy swapping of the socket-processor stack configurations under test. To swap the socket-processor stack configurations under test, a first test board including a first socket-processor stack is disconnected from the interface board of the test apparatus 200 and a second board including a second socket-processor stack is connected to the interface board. The modularity of the LLCR test apparatus technology described herein can accommodate new test boards that house new socket designs, processor stack configurations, and / or thermal management solutions for use with existing interface boards and wiring boards. Thus, organizations are not limited to a single test board design that may limit their ability to handle multiple thermal management solutions.

[0037] Figure 2 An example type of LLCR test apparatus configuration is illustrated where the test board is connected to the interface board at a location on the interface board that is physically offset from the location where the interface board is connected to the wiring board. This physical offset is at least driven by the presence of the cutout 230 in the stiffener plate on the back side that houses the test board 204. In test apparatus embodiments where the test board does not include a stiffener plate, a cutout in the interface board may not be required and the test board can be connected to the interface board at a location on the interface board that is closer to where the interface board is connected to the wiring board. This can result in a compact interface board design. Since the interface board may need to route a large number of signals from the test board to the wiring board, routing constraints may limit how much these areas can overlap.

[0038] The component boards (test board, interface board, wiring board) of the LLCR test device can be connected by any coupling component that allows the boards to be removably connected. For example, a pair of boards can be connected by pins on the first board contacting pads or inserted into holes on the second board. For example, pins 236 and 238 can be spring pins that connect the wiring board 212 to the interface board 208 and the contact resistance tester 216, respectively. In some embodiments, the spring pins are surface-mounted to conductive contacts at the surface of the printed circuit board. In some LLCR test device embodiments, spring pins are used for all board-to-board and board-to-tester connections (e.g., test board-interface board, interface board-wiring board, wiring board-tester connections). These spring pin connections can be made by aligning the spring pins on one board with the corresponding pads on another board and preloading the pins for stable resistance measurement. Removing the load allows the boards to be disconnected.

[0039] The LLCR test device disclosed herein may not suffer from the previously mentioned wire connection problems that existing LLCR testers may suffer from. Since the component boards of the LLCR test device disclosed herein are directly connected and the LLCR test device is directly connected to the test surface of the contact resistance tester, there are no wires that can cause wire connection problems (such as those caused by, for example, poor connections and / or parasitic wire resistance). Therefore, the LLCR test device technology disclosed herein can provide more accurate LLCR measurements by reporting fewer false open circuits.

[0040] Figure 3 is an example LLCR test method. Method 300 can be performed by, for example, an integrated circuit component manufacturer. At 304, a first resistance of a contact between first processing units attached to a first socket is measured by a contact resistance tester, the first socket being located on a first printed circuit board connected to a second printed circuit board, the second printed circuit board being connected to a third printed circuit board, the third printed circuit board being connected to the test surface of the contact resistance tester. At 308, after measuring the first resistance, the first printed circuit board is disconnected from the second printed circuit board. At 312, a fourth printed circuit board is attached to the second printed circuit board, the fourth printed circuit board including second processing units attached to a second socket. At 316, a contact resistance of a contact between the second processing units and the second socket is measured by the contact resistance tester. In other embodiments, method 300 can include one or more additional actions.

[0041] The LLCR test techniques described herein can be used to measure contact resistance in socket-processor stack configurations implemented in any of a variety of computing systems, including mobile computing systems (e.g., smartphones, tablet computers, laptop computers), non-mobile computing systems (e.g., desktop computers, servers, workstations, rack-level computing solutions (e.g., blade, tray, or pedestal computing systems)), and embedded computing systems (e.g., computing systems that are part of a vehicle, smart home appliances, consumer electronics or equipment, manufacturing equipment). As used herein, the term "computing system" includes computing devices and includes systems that comprise multiple discrete physical components.

[0042] Figure 4 is a block diagram of an example computing system that can perform LLCR measurements. Generally, Figure 4 the components shown in can communicate with the other components shown, although not all connections are shown for ease of illustration. Computing system 400 is a multi-processor system that includes a first processor unit 402 and a second processor unit 404 that includes point-to-point (P-P) interconnects. The point-to-point (P-P) interface 406 of processor unit 402 is coupled to the point-to-point interface 407 of processor unit 404 via a point-to-point interconnect 405. It will be understood that Figure 4 any or all of the point-to-point interconnects illustrated in can alternatively be implemented as multi-drop buses, and Figure 4 any or all of the buses illustrated in can be replaced by point-to-point interconnects.

[0043] Processor units 402 and 404 include multiple processor cores. Processor unit 402 includes processor core 408, and processor unit 404 includes processor core 410. Processor cores 408 and 410 can execute computer-executable instructions in a manner similar to or otherwise as discussed below in connection with Figure 5 or other ways.

[0044] The processor units 402 and 404 further include cache memories 412 and 414, respectively. The cache memories 412 and 414 can store data (e.g., instructions) used by one or more components of the processor units 402 and 404, such as the processor cores 408 and 410. The cache memories 412 and 414 can be part of the memory hierarchy for the computing system 400. For example, the cache memory 412 can locally store data that is also stored in the memory 416 to allow the processor unit 402 to access the data more quickly. In some embodiments, the cache memories 412 and 414 can include multiple cache levels, such as level 1 (L1), level 2 (L2), level 3 (L3), level 4 (L4), and / or other caches or cache levels. In some embodiments, one or more levels of the cache memory (e.g., L2, L3, L4) can be shared among multiple cores in a processor unit or among multiple processor units in an integrated circuit component. In some embodiments, the last level of the cache memory on an integrated circuit component can be referred to as the last level cache (LLC). One or more of the higher-level cache levels (smaller and faster caches) in the memory hierarchy can be located on the same integrated circuit die as the processor core, and one or more of the lower cache levels (larger and slower caches) can be located on an integrated circuit die that is physically separate from the processor core integrated circuit die.

[0045] Although the computing system 400 is shown as having two processor units, the computing system 400 can include any number of processor units. Additionally, a processor unit can include any number of processor cores. A processor unit can take various forms, such as a central processing unit (CPU), a graphics processing unit (GPU), a general-purpose GPU (GPGPU), an accelerated processing unit (APU), a field-programmable gate array (FPGA), a neural network processing unit (NPU), a data processor unit (DPU), an accelerator (e.g., a graphics accelerator, a digital signal processor (DSP), a compression accelerator, an artificial intelligence (AI) accelerator), a controller, or other types of processing units. Accordingly, a processor unit can be referred to as an XPU (or xPU). Additionally, a processor unit can include one or more of these various types of processing units. In some embodiments, the computing system includes one processor unit having multiple cores, and in other embodiments, the computing system includes a single processor unit having a single core. As used herein, the terms “processor unit” and “processing unit” can refer to any processor, processor core, component, module, engine, circuitry, or any other processing element described or referenced herein.

[0046] The processor units 402 and 404 further include memory controller logic (MC) 420 and 422. As Figure 4 shown, MCs 420 and 422 control memories 416 and 418 coupled to the processor units 402 and 404, respectively. Memories 416 and 418 can include various types of volatile memories (e.g., dynamic random access memory (DRAM), static random access memory (SRAM)) and / or non-volatile memories (e.g., flash memory, chalcogenide-based phase change non-volatile memory), and include one or more layers of the memory hierarchy of the computing system. Although MCs 420 and 422 are illustrated as integrated into the processor units 402 and 404, in alternative embodiments, the MCs can be external to the processor units.

[0047] The processor units 402 and 404 are coupled to an input / output (I / O) subsystem 430 via point-to-point interconnects 432 and 434. Point-to-point interconnect 432 connects the point-to-point interface 436 of the processor unit 402 to the point-to-point interface 438 of the I / O subsystem 430, and point-to-point interconnect 434 connects the point-to-point interface 440 of the processor unit 404 to the point-to-point interface 442 of the I / O subsystem 430. The input / output subsystem 430 further includes an interface 450 that couples the I / O subsystem 430 to a graphics engine 452. The I / O subsystem 430 and the graphics engine 452 are coupled via a bus 454.

[0048] The input / output subsystem 430 is further coupled to a first bus 460 via an interface 462. The first bus 460 can be a Peripheral Component Interconnect Express (PCIe) bus or any other type of bus. Various I / O devices 464 can be coupled to the first bus 460. A bus bridge 470 can couple the first bus 460 to a second bus 480. In some embodiments, the second bus 480 can be a Low Pin Count (LPC) bus. Various devices can be coupled to the second bus 480, including, for example, a keyboard / mouse 482, an audio I / O device 488, and a storage device 490, such as a hard disk drive, a solid state drive, or another storage device for storing computer-executable instructions (code) 492 or data. The code 492 can include computer-executable instructions for performing the methods described herein. Additional components that can be coupled to the second bus 480 include the communication device(s) 484, which can provide communication between the computing system 400 and one or more wired or wireless networks 486 (e.g., Wi-Fi, cellular, or satellite networks) via one or more wired or wireless communication links (e.g., wires, cables, Ethernet connections, radio frequency (RF) channels, infrared channels, Wi-Fi channels) using one or more communication standards (e.g., the IEEE 402.11 standard and its supplements).

[0049] In embodiments where the communication device 484 supports wireless communication, the communication device 484 can include wireless communication components coupled to one or more antennas to support communication between the computing system 400 and external devices. The wireless communication components can support various wireless communication protocols and technologies, such as Near Field Communication (NFC), IEEE 1002.11 (Wi-Fi) variants, WiMax, Bluetooth, Zigbee, 4G Long Term Evolution (LTE), Code Division Multiple Access (CDMA), Universal Mobile Telecommunications System (UMTS), and Global System for Mobile Communications (GSM), as well as 5G broadband cellular technologies. Additionally, a wireless modem can support communication with one or more cellular networks for data and voice communication within a single cellular network, between cellular networks, or between the computing system and the Public Switched Telephone Network (PSTN).

[0050] System 400 may include removable memory, such as flash memory cards (e.g., SD (Secure Digital) cards), memory sticks, subscriber identity module (SIM) cards. The memory in System 400 (including caches 412 and 414, memories 416 and 418, and storage device 490) may store data and / or computer-executable instructions for executing operating system 494 and application programs 496. Example data includes web pages, text messages, images, sound files, video data, and LLCR measurement data that will be sent by System 400 to one or more network servers or other devices and / or received from one or more network servers or other devices via one or more wired or wireless networks 486, or that are for use by System 400. System 400 may also access external memory or storage devices (not shown), such as external hard disk drives or cloud-based storage devices.

[0051] Operating system 494 may control Figure 4 the allocation and use of the illustrated components and support one or more application programs 496. Application programs 496 may include general computing system applications (e.g., email applications, calendars, contact managers, web browsers, messaging applications) and other computing applications such as LLCR measurement applications.

[0052] Computing system 400 may support various additional input devices such as touchscreens, microphones, cameras, trackballs, touchpads, light sensors, and one or more output devices such as one or more displays. Other possible input and output devices include piezoelectric and other haptic I / O devices. Any input or output device may be internal to, external to, or removably attachable to System 400. External input and output devices may communicate with System 400 via wired or wireless connections. Computing system 400 may further support an LLCR test surface, such as test surface 252( Figure 2 ). The computing system may cause electrical signals to be driven at coupling components located on the test surface and measure electrical signals at coupling components located on the test surface.

[0053] System 400 may further include at least one input / output port that includes physical connectors (e.g., USB, IEEE 1394 (FireWire), Ethernet, RS-232) and power (e.g., battery). Computing system 400 may further include one or more antennas coupled to one or more receivers, transmitters, and / or transceivers to enable functions related to wireless communication.

[0054] It will be understood that Figure 4Only one example computing system architecture is illustrated. Computing systems based on alternative architectures can be used to implement the techniques described herein. For example, instead of processors 402 and 404 and graphics engine 452 being on separate integrated circuits, the computing system can include a system-on-chip (SoC) integrated circuit that combines multiple processors, graphics engines, and additional components. Additionally, the computing system can connect its constituent components via a bus or point-to-point configuration different from the Figure 4 bus or point-to-point configuration shown. Additionally, Figure 4 the components illustrated in are not required or inclusive, as in alternative embodiments, the illustrated components can be removed and other components can be added.

[0055] Figure 5 is a block diagram of an example processor unit 500 that executes computer-executable instructions as part of implementing the techniques described herein. The processor unit 500 can be a single-threaded core or a multi-threaded core as it can include more than one hardware thread context (or “logical processor”) per processor unit.

[0056] Figure 5 Also illustrated is a memory 510 coupled to the processor unit 500. The memory 510 can be any memory described herein or any other memory known to those skilled in the art. The memory 510 can store computer-executable instructions 515 (code) executable by the processor unit 500.

[0057] The processor unit includes front-end logic 520 that receives instructions from the memory 510. The instructions can be processed by one or more decoders 530. The decoder 530 can generate micro-operations as its output, such as fixed-width micro-operations of a predefined format, or generate other instructions, micro-instructions, or control signals that reflect the original code instructions. The front-end logic 520 further includes register renaming logic 535 and scheduling logic 540, which typically allocate resources and queue operations corresponding to the translated instructions for execution.

[0058] The processor unit 500 further includes execution logic 550, which includes one or more execution units (EUs) 565-1 through 565-N. Some processor unit embodiments may include multiple execution units dedicated to a particular function or set of functions. Other embodiments may include only one execution unit or one execution unit that can perform a particular function. The execution logic 550 performs operations specified by code instructions. After completion of the execution of the operations specified by the code instructions, the backend logic 570 retires the instructions using retirement logic 575. In some embodiments, the processor unit 500 allows out-of-order execution but requires in-order retirement of instructions. The retirement logic 575 may take various forms known to those skilled in the art (e.g., a reorder buffer or the like).

[0059] The processor unit 500 is transformed during the execution of instructions, at least with respect to the output generated by the decoder 530, the hardware registers and tables used by the register renaming logic 535, and any registers (not shown) modified by the execution logic 550.

[0060] Any disclosed method (or a part thereof) may be implemented as computer-executable instructions or a computer program product. Such instructions may cause a computing system or one or more processor units capable of executing computer-executable instructions to perform any disclosed method. As used herein, the term "computer" refers to any computing system, device, or machine described or referred to herein and any other computing system, device, or machine capable of executing instructions. Thus, the term "computer-executable instructions" refers to instructions that can be executed by any computing system, device, or machine described or referred to herein and any other computing system, device, or machine capable of executing instructions.

[0061] Any data created and / or used during the implementation of the disclosed technology, as well as computer-executable instructions or computer program products, can be stored on one or more tangible or non-transitory computer-readable storage media, such as volatile memory (e.g., DRAM, SRAM), non-volatile memory (e.g., flash memory, chalcogenide-based phase change non-volatile memory), optical media discs (e.g., DVD, CD), and magnetic storage devices (e.g., tape storage devices, hard disk drives). The computer-readable storage media can be included in computer-readable storage devices, such as solid-state drives, USB flash drives, and memory modules. Alternatively, any method (or a part thereof) disclosed herein can be performed by hardware components including non-programmable circuitry. In some embodiments, any method herein can be performed by a combination of non-programmable hardware components and one or more processing units that execute computer-executable instructions stored on a computer-readable storage media.

[0062] The computer-executable instructions can be, for example, part of an operating system of a computing system, an application stored locally on the computing system, or a remote application accessible to the computing system (e.g., via a web browser). Any method described herein can be performed by computer-executable instructions executed by a single computing system or one or more networked computing systems operating in a network environment. The computer-executable instructions and updates to the computer-executable instructions can be downloaded to the computing system from a remote server.

[0063] Furthermore, it will be understood that the implementation of the disclosed technology is not limited to any particular computer language or program. For example, the disclosed technology can be implemented by software written in C++, C#, Java, Perl, Python, JavaScript, Adobe Flash, C#, assembly language, or any other programming language. Similarly, the disclosed technology is not limited to any particular computer system or hardware type.

[0064] In addition, any software-based embodiment (including, for example, computer-executable instructions for causing a computer to perform any of the disclosed methods) can be uploaded, downloaded, or remotely accessed via suitable communication means. Such suitable communication means include, for example, the Internet, the World Wide Web, an intranet, a cable (including a fiber optic cable), magnetic communication, electromagnetic communication (including RF, microwave, ultrasonic, and infrared communication), electronic communication, or other such communication means.

[0065] As used in the present application and claims, a list of items joined by the term "and / or" may mean any combination of the listed items. For example, the phrase "A, B, and / or C" may mean A; B; C; A and B; A and C; B and C; or A, B, and C. As used in the present application and claims, a list of items joined by the term "at least one of..." may mean any combination of the listed terms. For example, the phrase "at least one of A, B, or C" may mean A; B; C; A and B; A and C; B and C; or A, B, and C. In addition, as used in the present application and claims, a list of items joined by the term "one or more of..." may mean any combination of the listed terms. For example, the phrase "one or more of A, B, and C" may mean A; B; C; A and B; A and C; B and C; or A, B, and C.

[0066] The disclosed methods, apparatuses, and systems should not be construed as limiting in any way. Instead, the present disclosure is directed to all novel and non-obvious features and aspects of the various disclosed embodiments, both individually and in various combinations and sub-combinations with each other. The disclosed methods, apparatuses, and systems are not limited to any particular aspect or feature or combination thereof, nor do the disclosed embodiments require the presence of any one or more specific advantages or problems to be solved.

[0067] For the purpose of better understanding, the operating theories, scientific principles or other theoretical descriptions presented herein with reference to the devices or methods of the present disclosure have been provided, and are not intended to be limiting in scope. The devices and methods in the appended claims are not limited to those devices and methods that operate in the manner described by such operating theories.

[0068] Although the operations of some disclosed methods are described in a particular sequential order for ease of presentation, it will be understood that this description includes rearrangement unless the specific language set forth herein requires a particular order. For example, the operations described in sequence may be rearranged or performed simultaneously in some cases. In addition, for simplicity, the accompanying drawings may not illustrate the various ways in which the disclosed methods may be used in conjunction with other methods.

[0069] As used in this application and the claims, a list of items joined by the term "and / or" can mean any combination of the listed items. For example, the phrase "A, B, and / or C" can mean A; B; C; A and B; A and C; B and C; or A, B, and C. As used in this application and the claims, a list of items joined by the term "at least one of..." can mean any combination of the listed terms. For example, the phrase "at least one of A, B, or C" can mean A; B; C; A and B; A and C; B and C; or A, B, and C. Further, as used in this application and the claims, a list of items joined by the term "one or more of..." can mean any combination of the listed terms. For example, the phrase "one or more of A, B, and C" can mean A; B; C; A and B; A and C; B and C; or A, B, and C.

[0070] As used in this application and the claims, the phrase "each of..." or "respective of..." followed by a list of items described or stated as having a property, characteristic, etc. means that all of the items in the list have the stated or described property, characteristic, etc. For example, the phrase "each of A, B, or C includes a side wall" or "respective of A, B, or C includes a side wall" means that A includes a side wall, B includes a side wall, and C includes a side wall.

[0071] The disclosed methods, apparatuses, and systems should not be construed in any way as limiting. Instead, the present disclosure is directed to all novel and non-obvious features and aspects of the various disclosed embodiments, alone and in various combinations and sub-combinations with each other. The disclosed methods, apparatuses, and systems are not limited to any particular aspect or feature or combination thereof, and the disclosed embodiments do not require the presence of any one or more particular advantages or problem solutions.

[0072] For purposes of better understanding, an operational theory, scientific principle, or other theory description of the disclosed apparatus or method has been provided herein, and is not intended to be limiting in terms of scope. The apparatuses and methods in the appended claims are not limited to those that operate in the manner described by such operational theory.

[0073] Although, for convenience of presentation, the operations of some of the disclosed methods are described in a particular order of sequence, it will be understood that such description includes rearrangements, unless the particular language set forth herein requires a particular sequence. For example, the operations described in sequence may in some cases be rearranged or performed concurrently. In addition, for simplicity, the drawings may not show the various ways in which the disclosed methods can be used in conjunction with other methods.

[0074] The following examples relate to additional embodiments of the technology disclosed herein.

[0075] Example 1 is a device that includes: a first printed circuit board including a socket attached to a first surface of the first printed circuit board, a first plurality of coupling components located on the first surface of the first printed circuit board, a second plurality of coupling components located on a second surface of the first printed circuit board, the socket being attached to the first printed circuit board via the first plurality of coupling components, and the first plurality of coupling components being conductively coupled to the second plurality of coupling components through the first printed circuit board; a second printed circuit board including a third plurality of coupling components located on a first surface of the second printed circuit board and a fourth plurality of coupling components located on a second surface of the second printed circuit board, the third plurality of coupling components being conductively coupled to the fourth plurality of coupling components through the second printed circuit board; and a third printed circuit board including a fifth plurality of coupling components located on a first surface of the third printed circuit board and a sixth plurality of coupling components located on a second surface of the third printed circuit board, the fifth plurality of coupling components being conductively coupled to the sixth plurality of coupling components through the third printed circuit board, and the third printed circuit board being connectable to a contact resistance tester via the sixth plurality of coupling components.

[0076] Example 2 includes the device of Example 1, wherein the second printed circuit board is connectable to the first printed circuit board through the connection of the second plurality of coupling components to the third plurality of coupling components.

[0077] Example 3 includes the device of Example 1, wherein the second printed circuit board is connectable to the third printed circuit board through the connection of the fourth plurality of coupling components to the fifth plurality of coupling components.

[0078] Example 4 includes the device of any one of Examples 1-3, wherein the sixth plurality of coupling components includes a plurality of spring pins.

[0079] Example 5 includes the device of any one of Examples 1-4, further including a processing unit attached to the socket.

[0080] Example 6 includes the device of Example 5, further including a radiator attached to the processing unit.

[0081] Example 7 includes the device of Example 6, wherein the radiator is a first radiator, and the device further includes: a second radiator; a first heat transfer device attached to the second radiator at a first end of the first heat transfer device and attached to the first radiator at a second end of the first heat transfer device; a third radiator; and a second heat transfer device attached to the third radiator at a first end of the second heat transfer device and attached to the third radiator at a second end of the second heat transfer device.

[0082] Example 8 includes the device of Example 7, wherein the first heat transfer device includes a heat pipe or a thermosyphon.

[0083] Example 9 includes the apparatus of Example 5, further comprising: a steam chamber attached to the processing unit; a radiator attached to the steam chamber; and a heat exchanger attached to the steam chamber through one or more pipes.

[0084] Example 10 includes the apparatus of any one of Examples 1-9, further comprising a contact resistance tester.

[0085] Example 11 includes the apparatus of any one of Examples 1-10, wherein the apparatus is portable.

[0086] Example 12 includes the apparatus of any one of Examples 1-11, wherein the third printed circuit board includes a flexible printed circuit board.

[0087] Example 13 includes the apparatus of Example 12, wherein the flexible printed circuit board enables the first printed circuit board and the second printed circuit board to be oriented non-parallel to the test surface of the contact resistance tester.

[0088] Example 14 includes the apparatus of Example 10, wherein the contact resistance tester includes a test surface having a first area, and a second plurality of coupling components define a second area, and the second area is larger than the first area.

[0089] Example 15 includes the apparatus of Example 10, wherein the contact resistance tester includes a test surface having a first length and a first width, and the area defined by the second plurality of coupling components has a second length and a second width, and the second length is greater than the first length or the second width is greater than the first width.

[0090] Example 16 includes the apparatus of Example 10, further comprising a contact resistance tester, the contact resistance tester includes a test surface located in a recess of the contact resistance tester, the recess has a depth, and the third printed circuit board has a height greater than the depth of the recess.

[0091] Example 17 includes an apparatus that includes: a contact resistance tester; a first printed circuit board including a socket attached to a first surface of the first printed circuit board, a first plurality of coupling components located on the first surface of the first printed circuit board, and a second plurality of coupling components located on a second surface of the first printed circuit board, the socket being attached to the first printed circuit board via the first plurality of coupling components, and the first plurality of coupling components being conductively coupled to the second plurality of coupling components through the first printed circuit board; a second printed circuit board including a third plurality of coupling components located on a first surface of the second printed circuit board and a fourth plurality of coupling components located on a second surface of the second printed circuit board, the third plurality of coupling components being conductively coupled to the fourth plurality of coupling components through the second printed circuit board; and a third printed circuit board including a fifth plurality of coupling components located on a first surface of the third printed circuit board and a sixth plurality of coupling components located on a second surface of the third printed circuit board, the fifth plurality of coupling components being conductively coupled to the sixth plurality of coupling components through the third printed circuit board, and the third printed circuit board being connected to the contact resistance tester through the sixth plurality of coupling components.

[0092] Example 18 includes the apparatus of Example 17, wherein the second printed circuit board is connectable to the first printed circuit board through a connection of the second plurality of coupling components to the third plurality of coupling components.

[0093] Example 19 includes the apparatus of Example 17, wherein the second printed circuit board is connectable to the third printed circuit board through a connection of the fourth plurality of coupling components to the fifth plurality of coupling components.

[0094] Example 20 includes the apparatus of any one of Examples 17 - 19, wherein the sixth plurality of coupling components includes a plurality of spring pins.

[0095] Example 21 includes the apparatus of any one of Examples 17 - 20, further including a processing unit attached to the socket.

[0096] Example 22 includes the apparatus of Example 21, further including a heat sink attached to the processing unit.

[0097] Example 23 includes the apparatus of Example 22, wherein the heat sink is a first heat sink, and the apparatus further includes: a second heat sink; a first heat transfer device attached to the second heat sink at a first end of the first heat transfer device and attached to the first heat sink at a second end of the first heat transfer device; a third heat sink; and a second heat transfer device attached to the third heat sink at a first end of the second heat transfer device and attached to the third heat sink at a second end of the second heat transfer device.

[0098] Example 24 includes the apparatus of Example 23, wherein the first heat transfer device includes a heat pipe or a thermosyphon.

[0099] Example 25 includes the apparatus of Example 21, further comprising: a steam chamber attached to the processing unit; a radiator attached to the steam chamber; and a heat exchanger attached to the steam chamber through one or more pipes.

[0100] Example 26 includes the apparatus of any one of Examples 17 - 25, wherein the apparatus is portable.

[0101] Example 27 includes the apparatus of any one of Examples 17 - 26, wherein the third printed circuit board includes a flexible printed circuit board.

[0102] Example 28 includes the apparatus of Example 27, wherein the flexible printed circuit board enables the first printed circuit board and the second printed circuit board to be oriented non - parallel to the test surface of the contact resistance tester.

[0103] Example 29 includes the apparatus of Example 17, wherein the contact resistance tester includes a test surface occupying a first area, and a second plurality of coupling components occupy a second area, and the second area is larger than the first area.

[0104] Example 30 includes the apparatus of Example 17, wherein the contact resistance tester includes a test surface having a first length and a first width, and the area defined by the second plurality of coupling components has a second length and a second width, and the second length is greater than the first length or the second width is greater than the first width.

[0105] Example 31 includes the apparatus of Example 17, further comprising a contact resistance tester, the contact resistance tester including a test surface located in a recess of the contact resistance tester, the recess having a depth, and the third printed circuit board having a height greater than the depth of the recess.

[0106] Example 32 includes a method, the method comprising: measuring a first resistance of contact between a first processing unit attached to a first socket, a first socket located on a first printed circuit board connected to a second printed circuit board, a second printed circuit board connected to a third printed circuit board, and the third printed circuit board connected to a test surface of a contact resistance tester, by the contact resistance tester; after measuring the first resistance, disconnecting the first printed circuit board from the second printed circuit board; attaching a fourth printed circuit board to the second printed circuit board, the fourth printed circuit board including a second processing unit attached to a second socket; and measuring a contact resistance of contact between the second processing unit and the second socket by the contact resistance tester.

[0107] Example 33 includes the method of Example 32, wherein the first printed circuit board is connected to the second printed circuit board via a first plurality of coupling components on the surface of the first printed circuit board that are connected to a second plurality of coupling components on the first surface of the second printed circuit board, and the second printed circuit board is connected to the third printed circuit board via a third plurality of coupling components on the second surface of the second printed circuit board that are connected to a fourth plurality of coupling components on the third surface of the third printed circuit board, and the third printed circuit board is connected to the test surface of the contact resistance tester via a fifth plurality of coupling components that are connected to a sixth plurality of coupling components on the test surface.

[0108] Example 34 includes the method of Example 32, wherein a heat sink is attached to the first processing unit, and the heat sink is at least partially submerged in a dielectric liquid during measurement of the first resistance.

[0109] Example 35 includes an apparatus comprising: a contact resistance tester including a test surface; and a connection member for conductively coupling a socket to a plurality of coupling components on the test surface, a processing unit attached to the socket, and a first area defined by where the socket is connected to the connection member is greater than a second area defined by where the plurality of coupling components on the test surface are connected to the connection member.

[0110] Example 36 includes the apparatus of Example 35, further comprising a heat sink attached to the processing unit.

[0111] Example 37 includes the apparatus of Example 36, wherein the heat sink is a first heat sink, and the apparatus further comprises: a second heat sink; a first heat transfer device attached to the second heat sink at a first end of the first heat transfer device and attached to the first heat sink at a second end of the first heat transfer device; a third heat sink; and a second heat transfer device attached to the third heat sink at a first end of the second heat transfer device and attached to the third heat sink at a second end of the second heat transfer device.

[0112] Example 38 includes the apparatus of Example 35, further comprising: a vapor chamber attached to the processing unit; a heat sink attached to the vapor chamber; and a heat exchanger attached to the vapor chamber through one or more pipes.

[0113] Example 39 includes the apparatus of any one of Examples 35 - 38, wherein the apparatus is portable.

[0114] An apparatus, comprising: a first printed circuit board including a socket attached to a first surface of the first printed circuit board, a first plurality of coupling components located on the first surface of the first printed circuit board, a second plurality of coupling components located on a second surface of the first printed circuit board, the socket being attached to the first printed circuit board via the first plurality of coupling components, and the first plurality of coupling components being conductively coupled to the second plurality of coupling components through the first printed circuit board; a second printed circuit board including a third plurality of coupling components located on a first surface of the second printed circuit board and a fourth plurality of coupling components located on a second surface of the second printed circuit board, the third plurality of coupling components being conductively coupled to the fourth plurality of coupling components through the second printed circuit board; and a third printed circuit board including a fifth plurality of coupling components located on a first surface of the third printed circuit board and a sixth plurality of coupling components located on a second surface of the third printed circuit board, the fifth plurality of coupling components being conductively coupled to the sixth plurality of coupling components through the third printed circuit board, and the third printed circuit board being connectable to a contact resistance tester via the sixth plurality of coupling components. Wherein, the second printed circuit board is connectable to the first printed circuit board through the connection of the second plurality of coupling components to the third plurality of coupling components, and the second printed circuit board is connectable to the third printed circuit board through the connection of the fourth plurality of coupling components to the fifth plurality of coupling components. Wherein, the sixth plurality of coupling components includes a plurality of spring pins. Further comprising a processing unit attached to the socket. Further comprising a heat sink attached to the processing unit. Further comprising a contact resistance tester. Wherein, the third printed circuit board includes a flexible printed circuit board, and the flexible printed circuit board enables the first printed circuit board and the second printed circuit board to be oriented in a non-parallel manner relative to a test surface of the contact resistance tester. Wherein, the contact resistance tester includes a test surface having a first area, the second plurality of coupling components defining a second area, and the second area being larger than the first area. Further comprising a contact resistance tester, the contact resistance tester including a test surface located in a recess of the contact resistance tester, the recess having a depth, and the third printed circuit board having a height greater than the depth of the recess.

[0115] An apparatus, comprising: a contact resistance tester; a first printed circuit board including a socket attached to a first surface of the first printed circuit board, a first plurality of coupling components located on the first surface of the first printed circuit board, and a second plurality of coupling components located on a second surface of the first printed circuit board, the socket being attached to the first printed circuit board via the first plurality of coupling components, and the first plurality of coupling components being conductively coupled to the second plurality of coupling components through the first printed circuit board; a second printed circuit board including a third plurality of coupling components located on a first surface of the second printed circuit board and a fourth plurality of coupling components located on a second surface of the second printed circuit board, the third plurality of coupling components being conductively coupled to the fourth plurality of coupling components through the second printed circuit board; and a third printed circuit board including a fifth plurality of coupling components located on a first surface of the third printed circuit board and a sixth plurality of coupling components located on a second surface of the third printed circuit board, the fifth plurality of coupling components being conductively coupled to the sixth plurality of coupling components through the third printed circuit board, the third printed circuit board being connected to the contact resistance tester through the sixth plurality of coupling components. Wherein, the second printed circuit board can be connected to the first printed circuit board through the connection of the second plurality of coupling components to the third plurality of coupling components, and the second printed circuit board can be connected to the third printed circuit board through the connection of the fourth plurality of coupling components to the fifth plurality of coupling components. Further comprising a processing unit attached to the socket. Further comprising: a first heat sink attached to the processing unit; a second heat sink; a first heat transfer device attached to the second heat sink at a first end of the first heat transfer device and attached to the first heat sink at a second end of the first heat transfer device; a third heat sink; and a second heat transfer device attached to the third heat sink at a first end of the second heat transfer device and attached to the third heat sink at a second end of the second heat transfer device. Further comprising: a vapor chamber attached to the processing unit; a heat sink attached to the vapor chamber; and a heat exchanger attached to the vapor chamber through one or more pipes. Wherein, the third printed circuit board includes a flexible printed circuit board, and the flexible printed circuit board enables the first printed circuit board and the second printed circuit board to be oriented in a non-parallel manner with respect to a test surface of the contact resistance tester. Wherein, the contact resistance tester includes a test surface having a first length and a first width, a region defined by the second plurality of coupling components has a second length and a second width, and the second length is greater than the first length or the second width is greater than the first width. Further comprising a contact resistance tester, the contact resistance tester including a test surface located in a recess of the contact resistance tester, the recess having a depth, and the third printed circuit board having a height greater than the depth of the recess.

[0116] A method includes: measuring, by a contact resistance tester, a first resistance of contact between a first processing unit attached to a first socket, the first socket on a first printed circuit board connected to a second printed circuit board, the second printed circuit board connected to a third printed circuit board, and the third printed circuit board connected to a test surface of the contact resistance tester; after measuring the first resistance, disconnecting the first printed circuit board from the second printed circuit board; attaching a fourth printed circuit board to the second printed circuit board, the fourth printed circuit board including a second processing unit attached to a second socket; and measuring, by the contact resistance tester, a contact resistance of contact between the second processing unit and the second socket. Wherein, the first printed circuit board is connected to the second printed circuit board via a first plurality of coupling components on a surface of the first printed circuit board connected to a second plurality of coupling components on a first surface of the second printed circuit board, the second printed circuit board is connected to the third printed circuit board via a third plurality of coupling components on a second surface of the second printed circuit board connected to a fourth plurality of coupling components on a third surface of the third printed circuit board, and the third printed circuit board is connected to the test surface of the contact resistance tester via a fifth plurality of coupling components connected to a sixth plurality on the test surface. Wherein, a heat sink is attached to the first processing unit, and the heat sink is at least partially submerged in a dielectric liquid during the measurement of the first resistance.

Claims

1. A device comprising: a first printed circuit board, comprising a socket attached to a first surface of the first printed circuit board, a first plurality of coupling components located on the first surface of the first printed circuit board, a second plurality of coupling components located on a second surface of the first printed circuit board, the socket attached to the first printed circuit board via the first plurality of coupling components, the first plurality of coupling components conductively coupled to the second plurality of coupling components through the first printed circuit board; a second printed circuit board including a third plurality of coupling components on a first surface of the second printed circuit board and a fourth plurality of coupling components on a second surface of the second printed circuit board, the third plurality of coupling components being conductively coupled to the fourth plurality of coupling components through the second printed circuit board; and The third printed circuit board includes a fifth plurality of coupling components located on a first surface of the third printed circuit board and a sixth plurality of coupling components located on a second surface of the third printed circuit board, the fifth plurality of coupling components are conductively coupled to the sixth plurality of coupling components through the third printed circuit board, and the third printed circuit board can be connected to a contact resistance tester through the sixth plurality of coupling components.

2. The device according to claim 1, wherein: The second printed circuit board is connectable to the first printed circuit board via connection of the second plurality of coupling components to the third plurality of coupling components.

3. The device according to claim 1, wherein: The second printed circuit board is connectable to the third printed circuit board via connection of the fourth plurality of coupling components to the fifth plurality of coupling components.

4. The device according to any one of claims 1 to 3, wherein: The sixth plurality of coupling components includes a plurality of spring pins.

5. The device according to any one of claims 1-3, further comprising a processing unit attached to the socket.

6. The apparatus of claim 5, further comprising a heat sink attached to the processing unit.

7. The device according to any one of claims 1 to 3, wherein: The third printed circuit board includes a flexible printed circuit board.

8. The device according to claim 7, wherein: The flexible printed circuit board enables the first printed circuit board and the second printed circuit board to be oriented in a non-parallel manner relative to a test surface of the contact resistance tester.

9. The device according to any one of claims 1 to 3, further comprising a contact resistance tester.

10. The device according to claim 9, wherein: The contact resistance tester includes a test surface having a first area, and a second plurality of coupling components defines a second area, the second area being larger than the first area.

11. The apparatus of claim 9, further comprising a contact resistance tester, the contact resistance tester comprising a test surface located in a recess of the contact resistance tester, the recess having a depth, the third printed circuit board having a height greater than the depth of the recess.

12. An apparatus comprising: Contact resistance tester; a first printed circuit board, comprising a socket attached to a first surface of the first printed circuit board, a first plurality of coupling components located on the first surface of the first printed circuit board, and a second plurality of coupling components located on a second surface of the first printed circuit board, the socket being attached to the first printed circuit board via the first plurality of coupling components, and the first plurality of coupling components being conductively coupled to the second plurality of coupling components through the first printed circuit board; a second printed circuit board including a third plurality of coupling components on a first surface of the second printed circuit board and a fourth plurality of coupling components on a second surface of the second printed circuit board, the third plurality of coupling components being conductively coupled to the fourth plurality of coupling components through the second printed circuit board; and The third printed circuit board includes a fifth plurality of coupling components located on a first surface of the third printed circuit board and a sixth plurality of coupling components located on a second surface of the third printed circuit board, the fifth plurality of coupling components are conductively coupled to the sixth plurality of coupling components through the third printed circuit board, and the third printed circuit board is connected to the contact resistance tester through the sixth plurality of coupling components.

13. The device according to claim 12, wherein: The second printed circuit board is connectable to the first printed circuit board by connecting the second plurality of coupling components to the third plurality of coupling components, and the second printed circuit board is connectable to the third printed circuit board by connecting the fourth plurality of coupling components to the fifth plurality of coupling components.

14. The device according to any one of claims 12-13, further comprising a processing unit attached to the socket.

15. The apparatus of claim 14, further comprising a heat sink attached to the processing unit.

16. The device according to claim 15, wherein: The heat sink is a first heat sink, and the device further comprises: Second radiator; a first heat transfer device attached to the second heat sink at a first end of the first heat transfer device and to the first heat sink at a second end of the first heat transfer device; A third radiator; and A second heat transfer device is attached to the third heat sink at a first end of the second heat transfer device and attached to the third heat sink at a second end of the second heat transfer device.

17. The device according to any one of claims 12-13, wherein: The third printed circuit board includes a flexible printed circuit board, wherein the flexible printed circuit board enables the first printed circuit board and the second printed circuit board to be oriented in a non-parallel manner relative to a test surface of the contact resistance tester.

18. The device according to claim 17, wherein: The contact resistance tester includes a test surface occupying a first area, and the second plurality of coupling components occupy a second area, and the second area is larger than the first area.

19. The device according to claim 17, wherein: The contact resistance tester includes a test surface having a first length and a first width, an area defined by the second plurality of coupling components has a second length and a second width, and the second length is greater than the first length or the second width is greater than the first width.

20. The apparatus of claim 17, further comprising a contact resistance tester, the contact resistance tester comprising a test surface located in a recess of the contact resistance tester, the recess having a depth, the third printed circuit board having a height greater than the depth of the recess.

21. A method comprising: measuring, by a contact resistance tester, a first resistance of contact between a first processing unit attached to a first socket, a first socket located on a first printed circuit board connected to a second printed circuit board, a second printed circuit board connected to a third printed circuit board, and a third printed circuit board connected to a test surface of the contact resistance tester; After measuring the first resistance, disconnecting the first printed circuit board from the second printed circuit board; attaching a fourth printed circuit board to the second printed circuit board, the fourth printed circuit board including a second processing unit attached to the second socket; and The contact resistance of the contact between the second processing unit and the second socket is measured by a contact resistance tester.

22. The method according to claim 21, wherein: The first printed circuit board is connected to the second printed circuit board via a first plurality of coupling components located on a surface of the first printed circuit board connected to a second plurality of coupling components located on a first surface of the second printed circuit board, the second printed circuit board is connected to the third printed circuit board via a third plurality of coupling components located on a second surface of the second printed circuit board connected to a fourth plurality of coupling components located on a third surface of the third printed circuit board, and the third printed circuit board is connected to a test surface of the contact resistance tester via a fifth plurality of coupling components connected to a sixth plurality located on the test surface.

23. The method according to claim 21, wherein: The heat sink is attached to the first processing unit, and the heat sink is at least partially submerged in the dielectric liquid during measuring the first resistance.

24. An apparatus comprising: A contact resistance tester, including a test surface; as well as A connecting member for conductively coupling the socket to a plurality of coupling components on a test surface, a processing unit attached to the socket, a first area defined by where the socket is connected to the connecting member being larger than a second area defined by where the plurality of coupling components on the test surface are connected to the connecting member.

25. The apparatus according to claim 24, further comprising: a first heat sink attached to the processing unit; Second radiator; a first heat transfer device attached to the second heat sink at a first end of the first heat transfer device and to the first heat sink at a second end of the first heat transfer device; Third radiator; and A second heat transfer device is attached to the third heat sink at a first end of the second heat transfer device and attached to the third heat sink at a second end of the second heat transfer device.

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