As artificial intelligence (AI) applications continue to advance, the semiconductor industry is seeing a clear shift toward larger device packages with increasingly higher ball counts. This trend places new demands on test hardware, particularly in the design and performance of spring probe housings. As these housings become more densely populated to accommodate high pin counts, mechanical robustness becomes a critical factor in ensuring reliable test performance. One of the most important mechanical challenges is housing bowing, which can compromise contact integrity, yield, and long-term reliability. This presentation will explore the mechanical considerations behind spring probe housing design and the growing importance of structural strength in high-density applications. We will share validated simulation methods for predicting and analyzing housing deflection under load conditions, providing engineers with practical approaches for ensuring accurate and reliable test results. Additionally, we will examine the role of spring probe pre-load, its impact on housing deflection, and how preload strategies can be optimized to balance mechanical stability with electrical performance requirements. Attendees will gain insight into proven modeling and verification techniques that help reduce the risks associated with mechanical deformation in advanced test hardware. By understanding these factors, test engineers and package designers can better anticipate challenges as device complexity continues to grow, ensuring both robust contactor performance and greater confidence in test outcomes.

ABSTRACT: A comprehensive program to chart the next generation high volume production test socket for NXP. That is for Automotive Network Processors, Secure Edge IOT and Microcontroller applications. metrechanical, there letic performance requiremento vation to cover all aspects chanical, thermal, electrical performance requirements. Analytical approach from modeling, simulation, and validation using Engineering Parameters to assess compliance to define standards. Confluence of different engineering disciplines to meet the needs of high speed 1/0 such as PCIE, Ethernet, MIPI, DDR with varying complexities and unique requirements. Vill present Modeled, Validated Mechanical, Thermal, Electrical parameters (Frequency, anc ime domain associated to test socket tor NXP device |/O Performance assessment includes actual device 1/O data-eye test results, and Post Signal Conditioning.

“Development of micro-bump and pad contactor technology for next-generation HBM semiconductor packaging” By Jaeseob Lee, Byungsung Lee, Wooseok Choi, and Tackyong Jang, Olum Material, Inc., Republic of Korea As the era of on-device artificial intelligence (AI) has come, the amount of data to be processed at high speed has increased, leading to an exponential increase in demand for HBM and low-power DRAM, such as LPDDR. HBM (High Bandwidth Memory), used in AI operations, high-performance computing, and graphics processing, narrows the physical distance between the GPU and memory and uses a three-dimensional high-speed memory interface using TSV (Through Silicon Via) and micro-bumps. As the number of memory chips stacked within HBM increases, the number of micro-bumps to be contacted increases exponentially (15,000 to 30,000 per individual HBM chip), therefore the pitch between micro-bumps is decreasing (50 to 70μm). Conventional test socket methods cannot support these fine-pitch and high-frequency evaluations. For this reason, HBMs are not fully inspected at the EDS level, and only abbreviated testing is performed using test pad contacts (size is bigger than 110-165μm and number is around 300-500 per chip). At the chip level, after sawing, a method for inspecting micro-bumps without damage has not been developed, and so they are shipped without any further inspection. This has led to HBM-related defects occurring at the PCB package level. Therefore, for current and next-generation HBMs, a new design testing socket is needed that enables 100% inspection without damage to the micro-bumps after final packaging and sawing, specifically for fine-pitch and high-frequency evaluation. Existing chip-level semiconductor test sockets utilize vertical pins and utilize spring or wire elasticity to contact the pad-terminals. This approach presents technical limitations, including limitations in fine-pitch tests, inability to measure high frequencies, increased micro-bump damage, short life-span, low reliability, and inability to operate at high temperatures. Therefore, the development of HBM test sockets using horizontal pins is necessary. Horizontal pins enable fine-pitch implementation using semiconductor processes, high-frequency evaluation via short transmission lines, micro-bump damage suppression via horizontal cantilever elasticity, and high-temperature/high-reliability evaluation via metal alloy bodies. We report the development of a horizontal cantilever pin using precision electro-forming technology, micro 3D insulation technology, and micro-bump contactor structure array technology. Furthermore, we demonstrate the results of a negligible SI loss at high bandwidth operation and high-temperature/high-reliability evaluation using special socket technology for the horizontal structure contactor. The semiconductor test socket market is currently growing exponentially. The test socket market is expected to account for approximately 1% of the DDR memory market and 2% of the HBM memory market. New market expansion and increased prices are expected due to the fine pitch. The test socket market size is expected to increase due to the expansion of applicable devices, and the demand for new test sockets is expected to be very high. We introduce test socket technology for HBM micro-bumps and propose the development of die carrier (D/C) sockets for HBM Direct Access (D/A) pads and probe card technology based on this technology. Additionally, we propose to expand development to include test sockets and probe cards for general semiconductor high-end products, and to include existing high-end products such as die test sockets for 2.5D and 3D packages such as LPDDR7 and GPUs.

When transitioning to high-volume automated semiconductor package testing, our team encountered a critical reliability issue: test sockets failing continuity after just 10-50 compressions due to foreign object debris contamination—far short of the vendor's 5,000-cycle guarantee. This caused frequent downtime, inventory depletion, and escalating costs for custom high pin-count sockets. A cross-functional investigation using SEM/EDS, profilometry, and contact resistance measurements revealed debris accumulation and pin array warpage exceeding specifications. We developed a comprehensive solution combining offline maintenance protocols, online cleaning integrated into automated test flows, and socket redesign. This resulted in a tenfold improvement in socket lifecycle—from as few as 10 to over 200 compressions on average—while maintaining throughput and test quality. This work demonstrates how integrating failure analysis, mechanical design, and data-driven maintenance can solve critical production challenges and establish engineering best practices for reliability improvement.

With the ever increasing bandwidth requirements for modern HPC devices, the high speed transmission lines running at 224G frequencies and higher needs to have accurate simulations that correlates well with measurements. In the past, physical properties like glass fibers, weave effects and copper roughness were not accounted in simulations. However, as the speed node progresses, the oversight of not include slightest deviations will cause mismatches at higher frequencies. One of the burning questions about highspeed transmission lines is how much impact surface roughness have on the overall performance of the links at higher speeds. In this paper, we will dissect materials analyze and measure the roughness of the laminates and summarize how much roughness impacts the overall signal integrity at higher frequencies

Modern SERDES interfaces, especially PAM4/6/8, demand coaxial socket designs with robust noise suppression. Traditional coax spring probe sockets rely on sliding contact between the probe barrel and socket bore to establish a return path to ground, shielding the signal and maintaining impedance. However, this grounding method is not consistently reliable. Oxidation and wear can prevent some spring probes from making sufficient contact, compromising signal integrity. This paper examines the impact of incomplete ground contact on high-speed interfaces and introduces a design approach that ensures consistent and complete grounding.

As speeds have increased in load board the integration of the socket into high speed RF and SERDES paths has become more important. Typical high speed testing is done though a loop-back path that goes from the DUT and "loops back" to the DUT, providing no way to measure this path without directly probing the tips of the socket. This is typically an extremely hard operation to accomplish with standard probes. In this presentation we will introduce the Pin-Field-Probe, a probe that allows us to probe a socket directly and see the path exactly as a DUT will see it, from tip of socket to tip of socket. We will also show what happens if it's not used and why it's so critical for accurate measurements. We will show real measurements of using standard wafer probes as well as other measuring the PCB directly and show the accuracy impact of measuring boards using those methods in comparison to an improved measurement probe. We will specifically be looking at the 224Gbps PAM4 signals as the signals we are trying to measure and compare all data against a fundamental bandwidth of 56 GHz.

Harmonic distortion is a challenging parameter to measure in a production test environment. It's critical to integrate this capability with DC parametric and other RF measurements, but with telecom applications demanding distortion levels lower than -80 dBc new hardware strategies are necessary. This webinar will compare hardware elements of a harmonic test setup, present measured results, and cover techniques to measure very low harmonic distortion <100dBc in the same system as DC parametric testing.

Yield issues have led to limited engineering silicon samples and prototype boards to support pre-production activities, resulting in huge engineering spending, delays in distributing samples to global engineering teams and customers, and impacting the time to market for product release. Inadequate infrastructure management capabilities and lack of deployment automation solutions also caused delays in engineering activities, as well as leading to divergence in technology standards and global deployment delays. Besides that, lack of integration with existing in-house engineering tools affects regression testing and validation speed, causing delays in design and engineering activities. All these limitations and problems caused excessive operation spending and impacting the time to market for product releases. oneLab is a web-based, cloud-centralized solution for lab management and operations. Featuring a full CI/CD pipeline, oneLab integrates various engineering tools for regression testing, enables global lab system search and sharing, offers API-as-a-service for VLAN switching, OS provisioning, and instant Virtual Machine creation, transforming the lab ecosystem into a cohesive Lab-as-a-Service capability. This simplifies lab operations, improves solution delivery time and increases user engagement with oneLab. oneLab modernizes and enhances design efficiency by providing a consolidated system management platform, allowing users to manage engineering and validation activities within a single web portal by leveraging IT infrastructure. oneLab has successfully demonstrated as a total solution for management & engineering users, supporting more than 50k systems in labs today.

As the solder composition changes from Sn-Ag-Cu to Sn-Ag-Cu+Ni-Bi, the life of the pogo pin is shortened during the test process. To improve this problem, we propose a new Pd Alloy material with low solder reactivity at the plunger-solder interface, and confirm that this material slows down the growth of IMC in Ni-Bi-added solder compared to the existing material. When manufacturing pogo pins using this new material, it was confirmed that the test life was improved compared to the existing Pd Alloy plunger material in the SAC+Ni-Bi composition solder.

Large High Pin Count AI Device Testing with Elastomer Socket

Abstract for Poster For AI connector and test socket, and high heat generating system, outstanding technology for test/connector spring probe pins enabling low resistance, high current carrying and high voltage in the limited pitch and space. In addition to the high performances, irregular high temperatures, vibrating condition and humidity, a specially designed spring probe pin is desperately needed in various industrial areas. In summary, the pin should be demonstrating performance at the small pitch and space to increase the density and height of board and decrease the size the equipment. The research and development efforts presented, the poster, - describe new technologies for high performance spring probe pins good for high frequency, high pin count, low resistance and current carrying for the pitches between 0.15mm and wider in the harsh operating conditions. - include with spring probe pins, in excellent and ideal design, made by stamping process and fully automated assembly process, improved electrical/mechanical performance. - also include pins by stamping, how to deal with big volume order with short lead time, how to match with automated socket assembly process, and how to maintain stable quality control. The poster will give details of research and development to evolve to the current state of knowledge and describe current product offering and their related performance characteristics.

“Semiconductor test socket” is a broad descriptor of a system that makes an electrical connection between a DUT (device under test) and a test board. In general, this system is made up of a mechanical fixture used to align and compress the DUT onto an electrical contact. While there are many different types of electrical contacts on the market, most of them will require a specified amount of mechanical force to make contact. The part of the assembly that applies this force is the socket lid. The lid assembly comes in a variety of shapes and styles depending on the number of contacts and the size of the device. In basic applications, a compression mechanism applies force to the DUT. The number of contacts drives the size and force required. For both low- and high-pin count assemblies, springs aid in keeping uniform force across the DUT image003.png image004.png . When ease of use is needed in higher-force applications, lid assemblies will include a leverage mechanism. The disadvantages of this system are in the precision machining needed to accurately apply the correct force and the inability of the force to be adjusted. A minor disadvantage is in the general wear on the socket mechanisms themselves, but almost all mentioned lid solutions share a similar component lifetime. We will show how the new socket lid using pneumatic technology can be scalable for use in low and high force applications, adjustable force for trouble shooting purpose, accurate, precise and repeatable values of force, reduced complexity of lid designs, especially in higher force applications and ability to control force in a plurality of areas across the DUT.

HPC Chip Complexity drives need for Integrated System-Level Test Solutions By Davette Berry, Senior Director of Business Development, Advantest Contributions from John Langmack, Product Manager, Advantest And Morten Jensen, Dir of Thermal Systems R&D, Advantest As the sophistication of semiconductor packaging continues to grow, so does the need for system-level test (SLT) in high volume production to ensure that high-performance processors, chiplets, and other advanced devices function as expected in real-world environments. Implementing SLT at production scale requires balancing cost, throughput, and test coverage with the complexities of reliably contacting these multidie packaged parts. We address the challenging integration of robotic automation, supplying kilowatts of power and heat dissipation, actuating sockets requiring hundreds of kilograms of compression force, propagating high-speed electrical signals with the software infrastructure to allow users to focus on optimal test of their parts. As scan test fabrics are incorporated into chip designs, high-speed serial ports, like PCIe, test coverage can be cost-effectively increased during SLT. Thermal management of power-hungry processors in aggressive workloads stresses both the DUT and the test infrastructure. Solutions today span from traditional air cooling to advanced liquid and refrigerant-based systems. SLT handlers must support repeated thermal cycling and actuation without compromising electro-mechanical stability or DUT safety. Machine learning and AI bring fresh opportunities to optimize test operations. Securely accessing actionable data in real-time must be designed into the SLT ecosystem both at the hardware and software driver levels. A multi-disciplinary, integrated solutions to these system-level challenges are presented.

The increasing complexity of testing equipment has made power supply monitoring and sequencing a significant design challenge. While software can be employed to address this issue, it often requires substantial development and testing efforts. To alleviate this burden an innovative solution designed for high channel power supply monitoring and sequencing with minimal software intervention. By providing a robust hardware foundation, the solution empowers hardware engineers to fully design and own their power supply tree without the need for extensive software development. This paper explores the benefits & limitations of the solution, highlighting its ability to simplify power supply management while maintaining excellent fidelity in delivering and sequencing power to testing equipment.

I. Overview and Implementation Burn-in test programs generally consist of sequential test steps running at varying power levels and temperature setpoints, each set by an operator to fit the specific needs and stress specifications desired for the device under test (DUT). In traditional applications, each test program will be made up of one or more deterministic test steps, running predetermined pattern sequences across each burn-in board (BIB). The step’s passing or failing is determined by the state of output lines at chosen cycles, with the significance of each steps’ results assigned ahead of running under a final disposition. With the External Program functionality proposed herein, users may instead opt to run custom programs and scripts in place of vectors to enable dynamic operation. External programs would be designed to fit the testing needs of each specific burn-in board, and as such, a scripting language like Python would be recommended for its rapid development timelines as well as the ease of both writing and reading new code. External programs would require either a tester library that would allow Python control of the system hardware, or otherwise a direct connection to controllable discrete hardware to interact with the BIB. With either method, Python would be able to send and receive commands to the device through communications protocols such as JTAG, SPI, and I2C. Each script could be adapted to be specific to the board under test, mapping data streams and communication packets to the board’s communication pins and integrating external libraries for more complex operations. As such, external programs would offer a great degree of freedom in their purpose and complexity to meet end-users’ needs. Program testing could also be integrated seamlessly with traditional vector-based testing, with individual test programs being comprised of any combination of these modes of operation. The two modes could also interact, with external programs dynamically conditioning hardware to function in a certain way for deterministic tests being executed later in the sequence. Figure 1 demonstrates the general flow of these two modes of operation, and where the two approaches diverge. Figure 1 – Simplified Test Program Flowchart External programs could be called with arguments specified by the user determining the desired operation. Upon calling their program, users may choose to recognize as many or few arguments in their script as they would like. For example, users may use arguments to specify which I/O grouping to target (for DUTs with multiple on-board chiplets or communication protocols) and the function to be called on that group’s corresponding pins. Scripts might also offer any number of additional command flags, allowing users to request debugging printouts at specific levels of verbosity, for instance, or specify logging details and formatting for results returned from the device or generated by the script. In certain cases, programs might use these flags to determine testing modes, testing multiple devices sequentially or in parallel to either expand on or streamline the results being reported. Along with user-specified arguments, software would need to pass a packet of information to the script, providing additional context about the run and program instance. Information on the current run and test step would be used to accurately log results, allowing users to correlate device feedback with the run’s activity feed. This information would also detail the number and positions of DUTs for each burn-in board under test. This would not only determine which positions are to be tested by the script and should have results returned, but would also enable more dynamic operations between DUT positions. The expected return value of the external program will be a similarly formatted packet, relaying the passing or failing status for each DUT being tested. The metric by which the script determines the passing of these devices is entirely at the discretion of its designer.   Figure 2 offers an example of how this exchange might be implemented. In this example, details regarding the current test conditions are compiled by the burn-in system’s software into a JSON packet, and are relayed to the external program to provide any necessary context. The external program, written in Python, takes this JSON packet in through its standard input data stream, determining which BIBs and DUTs should be tested. Additional user-defined parameters are passed in through the script’s arguments, which can be used to select different options within the script itself. The script proceeds with whatever testing has been defined for its implementation, and identifies which DUTs are passing or failing based on its own criteria. These results are then compiled back into a JSON packet and written into an output file for consideration in the final disposition. Figure 2 – Program Call Example Exchange   II. Potential Applications The proposed method of external program testing offers a promising new addition to burn-in solutions, and it is anticipated that these capabilities will only expand and evolve over time as more of the industry embraces this approach. With the flexibility afforded by external programs, burn-in systems would be able to provide many of the functional benefits of System Level Test (SLT), while still conducting these tests in the high-stress environment of burn-in. On top of utilizing test system hardware libraries, test programs can be written to adapt existing APIs directly. These could be functions already developed for other forms of logic testing, such as ATE, importing and harnessing their DLL files directly in the script. This would allow programs to take advantage of the device’s actual on-board functions, testing its functional behavior while the device undergoes stress testing. Engineers who might be less familiar with the specifics of the burn-in platform could easily interact with the device and implement new test routines, simply by using functions and libraries that are already familiar to them. If utilized in the test environment, this feature would enable the use of test routines that are not only dynamic, but reactive as well. Rather than simply assessing results and reporting back a disposition, an invoked program may instead consider those results and make an informed selection of follow-up sequences based on this feedback. In the typical development of a test program with vector testing, engineers will often troubleshoot a failing pattern over many iterations, repeatedly revisiting and regenerating the test pattern until the desired output is achieved. A reactive program could instead run a pattern and, in response to the failing sections, run different variations of the pattern to diagnose the issue further. This means that with appropriate understanding of the device’s behavior, external programs could first identify pattern failures, and then return feedback on why they may be failing and what could be improved going forward. This also offers more flexibility between the individual devices being tested. For instance, consider a board loaded with multiple different models of devices, each sharing the same footprint: an initial pattern could first prompt differences between the DUTs and, in response to their distinguishing outputs, choose proceeding patterns best suited to their individual characteristics. This would enable a single model of board to service an entire line of devices with the same program, requiring no manual distinction from the system’s operator. This flexibility would also afford greater freedom in how devices interact with each other, with the output of one device potentially informing the inputs of another, and with the board itself, potentially driving signals in hardware to optimize circuits for specific devices and conditions.   III. Interfacing & Debugging Not only would external programs offer a significant degree of flexibility to test programs in production and certification applications, but it could also vastly expand users’ troubleshooting capabilities. With scripts being able to implement many of the on-chip debugging capabilities available to the device, these can be leveraged in the pre-production stage to develop more optimized test programs. Furthermore, with the range of complexity offered to these custom scripts, users may choose to implement more interactive modes to manually call and evaluate their script’s functions as well. In an external program’s typical implementation, the user’s custom script would run commands based on the initial string of arguments provided and the internal feedback that may be received from test results and sequential operations. If the program were designed to adapt existing libraries with sufficient debugging capabilities, however, an active user could instead choose to input commands directly to the device and evaluate their results, rather than simply issue individual commands or pattern sequences at various test steps. Debugging functions could be called to make the device remotely accessible, allowing operators to interact with it over the local network, through remote access protocols such as SSH or Telnet. This would allow users to issue commands directly to their device through their native protocols, and in turn receive any feedback offered by their device’s on-chip diagnostic functions. If the script does not utilize existing device libraries, users may instead design their script to operate in a similarly interactive manner through a call-and-response mode, continuously querying the user to issue commands and directly displaying results and feedback. While the hands-on nature of these interactive testing modes would typically be undesirable for extended burn-in runs, the feedback generated in this phase can also inform the development of a finalized test program: if results from the device demonstrate that a certain function or command performs better under specific circumstances, an engineer may decide to call their program under those parameters, potentially ensuring better results and higher burn-in efficiency. If users plan to test certain aspects of the device with traditional vector patterns, they may first determine their ideal device mode and frequency settings with these interactive debugging methods, and then develop their final patterns according to this feedback. Alternatively, rather than interface with the device through the external program feature and its optional user APIs, users may instead opt to connect external hardware devices to interface with their boards. These may be devices that customers serve as a known benchmark to measure a device’s performance in the context of a burn-in test system, or an accessible debugging platform users can easily integrate with their burn-in boards. Connections can also be added to monitor any communications protocols peripheral to the device. Because external programs rely on actively manipulating I/O states to issue commands, these scripts may also interact directly with the board’s hardware, operating switches and multiplexors to adjust the behavior of the board’s subcircuits. A burn-in board could utilize a driver line a switch to reroute a set of JTAG pins to a different part of the device, for instance, altering where an external program utilizing those pins is targeting. An output signal could be redirected back to the device to provide a feedback loop, and reference clock sources could be toggled and adjusted on the fly. Features of this sort would be directly tied to the layout of the board, and as such can be tailored to help customers to match their specific needs.