On October 28, 2026, the Taiwanese business magazine Business Today (今周刊) reported that NVIDIA is considering PTFE (polytetrafluoroethylene) as the insulating material for the NVLink switch boards that connect GPUs at high speed. PTFE is a resin also used in non-stick coatings, and it is drawing attention as a material that can reduce signal transmission loss. An anonymous printed circuit board maker interviewed by the magazine named two candidates: switch boards for the future Rubin Ultra, and a next-generation midplane that connects boards in an orthogonal arrangement. However, both are the manufacturer's own analysis, and NVIDIA has not confirmed the final board specifications or the adoption of PTFE. Multilayer boards using PTFE already exist, so the key question is whether a board configuration for AI systems can deliver both low loss and stable mass-production quality.
Why change the insulating material for NVLink boards?
In AI systems, multiple GPUs exchange large volumes of data, so the interconnect bandwidth between GPUs is critical. NVIDIA's Vera Rubin platform, announced in January 2026, is said to offer NVLink 6 bandwidth of 3.6 TB/s per GPU and 260 TB/s across the entire Vera Rubin NVL72 rack. The former is a per-GPU figure and the latter a rack-level figure, so they measure different things. These are also published Rubin specifications and do not indicate which board materials will be used in Rubin Ultra.
According to Business Today, PTFE is being considered for the NVLink switch board that NVIDIA showed at the October OCP event. NVIDIA's event listing says OCP Global Summit 2026 ran from October 12 to 15. The candidate configurations mentioned in the report appear aimed at reducing signal attenuation when high-speed signals travel over long traces.
Signals on a board are carried by copper traces, but transmission loss is not determined by copper's properties alone. Copper-clad laminate, one of the base board materials, consists of copper foil bonded to an insulating material, and the electromagnetic field that accompanies a signal also extends into the insulation around the traces. The energy lost inside the insulating material is called dielectric loss. PTFE is attracting attention because it can keep this dielectric loss low.
However, choosing a low-dielectric-loss material does not guarantee lower loss along the entire transmission path. In a technical explanation of millimeter-wave transmission lines, board material maker Rogers divides signal loss into radiation loss, conductor loss, and dielectric loss. A low-dielectric-loss material helps limit attenuation, but rough copper surfaces increase conductor loss. This is a general technical explanation about millimeter-wave circuits, not a measured result of how much loss reduction PTFE would deliver on an NVLink board. Judging materials requires comparisons under matched conditions, such as frequency and trace structure.
Bonding and plating: the challenges of making PTFE multilayer boards
Circuit boards using PTFE are not a new idea. Rogers' processing guidelines for its RO3000/RO3200 series describe PTFE composites with added fillers and materials reinforced with woven glass, and also lay out how to fabricate double-sided and multilayer circuits. At the same time, they note that these materials are softer than typical rigid board materials and easily damaged during handling.
To make a multilayer board, several layers with formed traces must be stacked and bonded together. One material used for this is prepreg, a semi-cured bonding material impregnated with resin. Bonding films are also used for layer-to-layer attachment, and Rogers has commercialized CuClad 6700, a bonding film based on a CTFE thermoplastic copolymer, for multilayer circuits built on PTFE substrates. Its processing guidelines also list a variety of thermosetting and thermoplastic bonding materials.
Another key step is forming and plating the holes that electrically connect the layers. In a multilayer board, after holes are drilled, a conductive base layer is formed on the inner walls and then plated to secure electrical connections between layers. The RO3000/RO3200 guidelines call for activating the hole walls before forming that base layer. If this treatment is inadequate, metal adheres poorly, which can lead to plating defects. Sodium treatment and plasma treatment are introduced as specific methods.
The drilling step also requires suitable processing conditions. When evaluating drill life, the guidelines recommend taking into account the bonding material, the thickness of the inner-layer copper, and the overall board thickness, and checking cross-sections of the drilled holes. In other words, it is not enough for interlayer bonding and hole-wall plating each to work on its own; the entire manufacturing process, including the stacked materials and board thickness, must be designed appropriately.
PTFE's low-loss properties alone cannot settle the adoption question
Judging whether to adopt PTFE requires evaluating the material's electrical properties, multilayer bonding technology, hole-drilling and plating quality, and mass-production yield separately. The fact that manufacturing technology for PTFE multilayer boards already exists does not prove it can handle large-scale production for AI systems. Based on the Business Today report and Rogers' technical documents, the table below sorts out, at each stage from material to finished board, what can be confirmed and what remains unconfirmed for NVIDIA's use.
| Stage to verify | What existing documents confirm | What remains unconfirmed for NVIDIA |
|---|---|---|
| Material electrical properties | Rogers' explanation of millimeter-wave circuits describes dielectric loss as well as conductor loss from copper surface roughness | Loss of a finished transmission path using the candidate material, measured under the same conditions |
| Interlayer bonding | A bonding film for multilayer circuits on PTFE substrates has been commercialized | The bonding material and bonding conditions for the candidate board configuration |
| Hole drilling and plating | The RO3000/RO3200 processing guidelines describe methods for hole-wall activation and pre-plating treatment | Drilling and plating quality in the candidate configuration |
| Mass production of finished boards | Business Today reports an anonymous manufacturer's estimate of overall yield | The final product configuration, inspection conditions, and mass-production pass rate |
This table is not a direct comparison of performance figures across different products; it separates technically confirmed items from unconfirmed ones. Even if PTFE's low dielectric loss is a reason to choose it, on an actual board the stackup and hole quality affect both transmission characteristics and manufacturing quality, so evaluation of the finished product is essential. Rogers' technical documents support the idea that processing methods for PTFE multilayer boards are established, but they are not evidence that NVIDIA has adopted the company's products.
The "yield below 5%" figure is not a measured NVIDIA value
Business Today reported, citing an anonymous copper-clad laminate maker, that the industry currently estimates PTFE's overall yield at less than 5%. Overall yield refers to the proportion of products that end up as good units after passing through multiple manufacturing steps. However, the report does not disclose the product configuration, the factory, the quantities evaluated, or the inspection conditions behind the estimate. The figure therefore cannot be applied to all PTFE boards, nor treated as a measured value published by NVIDIA.
The development efforts of material makers should likewise be considered separately from whether NVIDIA has decided to adopt PTFE. According to Business Today, Taiwan's Elite Material (台光電) is building prototypes that combine its own prepreg with PTFE material from Taiwan Union Technology's affiliate (台虹). Meanwhile, Taiwan Union Technology (台燿) plans to continue its existing copper-clad laminate products while also working on PTFE products. The magazine also mentions investments by China's Shengyi Technology (生益科技) and Victory Giant Technology (勝宏科技), but these are development and investment trends drawn from interviews, not indications of specific order volumes or final customers.
The key point going forward is which board configuration NVIDIA ultimately adopts. Once the configuration is fixed, transmission loss measured under the same conditions and a mass-production pass rate with stated inspection conditions would make it possible to judge whether PTFE's low-loss characteristics can be put to use in an actual high-speed interconnect system. Full-scale adoption will depend not only on the material's advantages but on whether the required quality and volume can be secured reliably.