The ‘forced ascent’ of a traditional component
By 2026, the number of single node xPUs in AI computing clusters is rapidly evolving from 72 to 144 or even 512. When stamping shrapnel reaches its physical limit in high density scenarios at 56GHz+, a precision component with decades of history – the Pogo Pin – is pushed to the center of the AI interconnect stage. The new generation of AI server architectures such as NVIDIA GB200 and Rubin Ultra are forcing a switch in connection solutions, shifting from traditional stamping springs to Micro Pogo Pin micro spring pins. Single cabinet tens of thousands of pin level connections have become standard.
This technological revolution is packaged by industry narratives as a ‘victory of precision manufacturing’. But stripping away the marketing rhetoric, the rise of the spring top needle is not due to its own excellence, but rather the “remaining options” after traditional solutions have failed. Its innovation is almost entirely driven by the transmission of external pressure, rather than endogenous breakthroughs in the connector industry. Understanding this passive nature is a prerequisite for examining this technological revolution.
1、 Technological Breakthrough: The Physical Cost Behind Beautiful Numbers
1.1 “Perfect answer sheet” on the parameter table
From publicly available data, Micro Pogo Pin has indeed delivered an impressive performance report. The Micro Pogo high-speed socket developed by Toplink adopts PAM4 modulation method, with a fundamental frequency of up to 56GHz, achieving 224Gbps high-speed signal transmission, and the characteristic impedance is strictly controlled within 85 ± 5% Ohm. In the frequency range of 0-56GHz, the insertion loss is controlled within -0.5dB, the return loss is better than -15dB, and the near end crosstalk is lower than -35dB.
In terms of mechanical dimension, the working height of the product is 1.85mm, the total compression stroke is 0.6mm, the contact force is stable at 25gf in the working state, the needle spacing is set to 1.0mm, and the outer diameters of the signal needle and grounding needle are both less than 0.5mm. These parameters constitute an alternative reason for traditional stamping springs on paper – the residual pile effect of the cantilever beam structure can cause unacceptable high-frequency resonance in the frequency band above 56GHz, and the thermal warping deformation of high-power chips often requires a compensation stroke of ≥ 0.5mm. When the stamping spring is thinned to a working height of 2.1mm, the effective stroke is only 0.3mm left.
1.2 ‘Structural fragility’ obscured by numbers
However, what the parameter table won’t tell you is that the reliability issue of the spring ejector pin has never been truly resolved. The spring top pin itself is a multi component structure, formed by preloading three basic components: spring, needle tube, and needle shaft. It has multiple contact points and is prone to unstable contact and low impedance consistency. The probe often gets crooked during testing, requiring personnel to readjust, wasting a lot of time and labor costs. The problem of card PIN is inevitable due to the combination of multiple structures. As the pitch spacing decreases and the needle diameter becomes smaller, the risk of needle breakage gradually increases. The probe has a service life of less than 30000 times and is prone to wear and tear. After a certain service life, it is easy to cause poor contact and false measurement.
These are not “minor issues” that can be ignored, but structural fragility. In the scenario of tens of thousands of pins per cabinet in AI servers, any single pin failure may lead to a decrease in the interconnection performance of the entire cabinet. When the industry invests heavily in optimizing the signal integrity of spring top pins at 224Gbps, a fundamental question is: to what extent can it withstand continuous thermal cycling and mechanical vibrations in data center environments?
1.3 The “thermodynamic gamble” carried by high current
The rising power consumption of AI chips requires connectors to simultaneously carry larger currents. But in the spring pin, the current carrying capacity is limited by the cross-sectional area of the spring – the smaller the cross-section, the lower the current carrying capacity, and miniaturization precisely requires a smaller cross-section. When a large current flows through the spring, it generates heat, causing high temperature and softening, resulting in an increase in contact resistance, forming a positive feedback loop of “temperature rise → resistance rise → hotter”. In this game, the fault-tolerant space is extremely limited. The thermal cycling test shows that after 1000 cycles from -40 ° C to 125 ° C, the insertion and extraction force attenuation of the spring pin needs to be controlled within ≤ 15%. However, in the actual working conditions of the AI server, the frequency and amplitude of thermal cycling far exceed this test condition.
2、 Manufacturing dilemma: When ‘zero burrs’ become the ceiling
2.1 Illusion of “Single Point Optimization”
The industry tends to view the technological advancements of spring top pins as isolated events and overlook their position in the entire interconnected system. In fact, the spring pin is just one link in the signal chain from the chip to the system, and its performance limit is jointly constrained by upstream and downstream devices. When the Nyquist frequency of 448Gbps PAM4 reaches 112GHz, the insertion loss of traditional ultra-low loss PCBs reaches about 1.9dB/inchand the maximum transmission distance is only about 4 inches. In the face of this physical constraint, the optimization space for the signal integrity of the spring pin itself is extremely limited.
This means that even if the spring top pin reaches its limit in its own dimension, if the channel design at the system level fails to synchronize breakthroughs, the overall interconnection performance will still be constrained by the weakest link. Placing hope on the miniaturization and high-speed development of spring top pins, while neglecting the synchronous breakthroughs in PCB board, packaging architecture, and system level signal integrity design, is a dangerous simplification.
The realistic dilemma of 2.2 micron scale manufacturing
The manufacturing of spring top pins is facing systematic challenges such as “difficult welding of high reactive materials, difficult control of microstructures, difficult compatibility of multiple material combinations, difficult suppression of thermal effects, and difficult guarantee of consistency”. The manufacturing of complex spring needles requires high-precision machining equipment and processes, such as laser cutting and precision grinding, which place extremely high demands on equipment and technology. The high reflectivity of copper alloys requires higher welding energy input, but miniaturized structures are extremely sensitive to thermal effects, and optimizing a single process is difficult to fundamentally solve the problem.
What is even more alarming is that the needles and needle tubes of pogo pins are traditionally produced by microfabrication processes, requiring multiple time-consuming processing steps, high production costs, and problems such as accumulated damage, inter process transport positioning, deformation defects, surface smoothness, and dimensional accuracy, which may become obstacles to systematic mass production.
2.3 Structural Contradiction between Yield and Cost
The gross profit margin of the global Pogo Pin industry is generally between 25% and 40%, with a standard universal single needle unit price of approximately 0.02 to 0.30 US dollars. However, the Micro Pogo Pin required for AI servers has much higher precision, material, and process requirements than general products, and the gap between its manufacturing cost and selling price is widening. When customers demand “zero burr” delivery and slow wire precision of ± 2 microns, yield loss and cost increase will ultimately be transmitted to the deployment cost of the entire AI infrastructure.
The unit price of European and American orders is about 40% higher than that of domestic chains. Whether this price difference is sustainable depends on whether AI computing power investment can maintain the current growth rate in the long run. Once the computing power investment cycle rebounds, the connector industry may face severe utilization tests for the production capacity and process capabilities invested to meet extreme standards.
3、 The undercurrent of alternative solutions: Is the spring top needle the endpoint or the transition?
3.1 “Dimensionality Reduction Strike” of Liquid Metal Interconnection
While the spring ejector pin accelerates iteration, a more disruptive technological route is taking shape. The liquid metal interconnect technology based on gallium alloy has demonstrated ultra-low contact resistance at the laboratory level. Gallium indium eutectic alloy is used for through-hole metallization in glass packaging, which can achieve fine pitch and thermo mechanical reliability interconnection in 2.5D heterogeneous integration. Liquid metal electrodes combine metal conductivity with fluid deformability, providing unique advantages for flexible electronic, sensing, and biological interfaces. However, their oxidation mediated interface behavior may also increase contact resistance and interface instability.
This means that the “golden age” of spring top pins in the field of AI interconnection may be shorter than industry expectations. As liquid metal interconnects move from the laboratory to mass production, spring top pins are no longer facing the question of “how to do it better”, but rather the question of “whether it is still necessary”.
3.2 CPO and NPO: Eliminating “Contact” at the Architecture Level
At a longer scale, CPO (co encapsulated optics) and NPO (near encapsulated optics) technologies are attempting to eliminate the dependence on physical spring contacts at the architectural level. The Open CPX MSA has officially released the “Specification for Co encapsulated and Near encapsulated Connectors and Optical Modules”, which supports up to 7.2Tbps connections per slot and defines standardized pluggable CPO/NPO module shapes based on 200Gbps signaling per channel. The detachable glass waveguide connector launched by Gexin and Corning uses ion exchange technology to prepare low loss glass waveguides. The silicon optical passive coupling loss is less than 1.5dB/face, forming a thin and pluggable physical contact solution.
The new product release of Huafeng Technology in the field of AI computing power also confirms this trend. Its near package optical solution significantly shortens the signal transmission distance by integrating the optical engine package near the ASIC chip, reduces transmission loss by 20dB, optimizes power efficiency by 30% to 50%, and solves the dead cycle of “higher speed, more uncontrollable power consumption”.
The maturity of these technologies will gradually erode the necessity of spring top pins in high-density interconnect scenarios. Spring top pins are currently widely adopted, partly because more radical technological solutions are not yet mature – this is a ‘transitional dividend’ rather than a final victory.
4、 Deep questioning of engineering culture
4.1 The Difference between Passive Adaptation and Active Innovation
A core criticism of the technological revolution of spring top pins is that their innovation is almost entirely driven by the transmission of external pressure. The manufacturing of high-speed connectors is being driven by the demand for AI computing power, which is transmitted from the system application end to the component end. The repeated mention of “Micro Pogo Pin replacing stamped shrapnel” in industry narratives can easily create a single point breakthrough illusion of technological progress. But the bottleneck of AI interconnection has never been a problem of a single component – improving connectivity requires full chain collaboration from chip packaging, PCB boards, connectors, cables to system architecture.
This passive adaptation mode carries structural risks. When the industry invests heavily in optimizing the performance of spring top pins at 224Gbps, if the technological path in the 448Gbps era undergoes a fundamental shift – such as CPO or liquid metal interconnects maturing prematurely – these investments may face large-scale sinking. Although China’s connector industry has maintained its position as the world’s largest manufacturing country since 2016, the key basic material for manufacturing highly reliable connectors – copper contact parts – has long relied on imports, and the industry chain has problems of being “large but not strong”, “comprehensive but not refined”, and “tough but brittle”. If the bottleneck of the core material of the spring ejector pin cannot be overcome, the results of technological iteration may only revolve around the peripheral process.
4.2 Lack of Standard Discourse Power
A fact deliberately downplayed by industry narratives is that the technical standard setting power of spring top pins is not in the hands of manufacturing companies. Domestic connector manufacturers are striving to catch up in standard setting – the PCIe 5.0 electrical connector group standard, led by Xingwanlian Electronics, was officially released in August 2026, filling the gap in standard supply in this niche field in China. Huafeng Technology, as the core initiator of the OPEN NPO Alliance, has jointly developed NPO Socket connectors with Huawei.
But these efforts are still in the stage of ‘following international standards and aligning international indicators’. Domestic manufacturers need to “reference and align the product technical specifications of international manufacturers and establish a connector reliability testing program standard that is in line with domestic and international standards”, which means that in terms of defining the interconnection architecture, domestic spring pin manufacturers are still the recipients of the rules rather than the makers. When there is a fundamental shift in the technological path, the switching cost for followers is much higher than that for definers.
4.3 Who is paying for ‘zero burrs’?
The proposal of the “zero burr” delivery standard is essentially to compensate for the insufficient margin in the design end by extreme pressing at the manufacturing end. When connector manufacturing is required to achieve micrometer level precision and ceiling level burr control, yield loss and cost increase will ultimately be transmitted to the deployment cost of the entire AI infrastructure. As CPO and liquid metal interconnect technologies gradually mature, the production capacity and process capabilities invested to meet the extreme standards of spring top pins will face a severe test of whether they can be migrated to the new architecture.
Conclusion: Find the initiative in the “remaining options”
The rise of spring top pins in the wave of AI computing power is a typical case of “forced innovation”. It is not the result of proactive technological breakthroughs in the connector industry, but rather a product of AI computing power demand reshaping upstream supply chains in extreme ways. The performance data of Micro Pogo Pin at 224Gbps indeed proves the potential of precision engineering, but the beautiful numbers on the parameter table cannot conceal the structural contradictions in reliability, manufacturing, and cost.
Recognizing the current technological value of the spring top pin does not mean accepting the narrative that the spring top pin is the ultimate solution for AI interconnection. What is truly worth questioning is whether the spring pin industry has the ability to shift from “passive adaptation” to “active definition” as technologies such as liquid metal interconnects and CPO/NPO gradually mature? In the next stage of continuous increase in computing power demand, can it transform from “remaining options” to “selected solutions”
Post time: Sep-22-2026