ITEQ IT-998: The Ultimate Super Ultra-Low Loss PCB Material for 800G Ethernet Design

Welcome to the bleeding edge of high-speed hardware architecture. As data centers, artificial intelligence (AI) clusters, and telecommunication infrastructures push the boundaries of bandwidth, the transition from 400G to 800G Ethernet has fundamentally rewritten the rules of printed circuit board (PCB) design. To meet these extreme signal integrity demands, ITEQ IT-998 has emerged as a premier super ultra-low loss PCB material.

For PCB engineers, hardware architects, and signal integrity specialists, selecting the right laminate is no longer just a matter of checking a datasheet; it is the most critical architectural decision in the entire system design. When dealing with 112G and 224G PAM4 signaling, the margin for error effectively drops to zero. Standard FR-4 materials, and even early-generation high-speed laminates, simply cannot handle the insertion loss, impedance variations, and thermal stress of modern 1RU switch chassis or AI server mainboards.

In this comprehensive engineering guide, we will break down the material science, fabrication realities, and signal integrity benefits of the ITEQ IT-998 laminate. By understanding its core properties, competitive advantages, and stackup design guidelines, you will be fully equipped to deploy this next-generation material in your 800G Ethernet infrastructure and beyond.

The Signal Integrity Bottleneck in 800G Ethernet

To understand why ITEQ IT-998 is necessary, we must first examine the physics of 800G Ethernet. Unlike legacy networking standards that relied on Non-Return-to-Zero (NRZ) encoding, 800G Ethernet relies heavily on 112 Gbps or 224 Gbps per-lane speeds using Pulse Amplitude Modulation 4-Level (PAM4) encoding.

PAM4 transmits two bits of data per clock cycle by utilizing four distinct voltage levels. While this doubles the data throughput without doubling the bandwidth, it severely shrinks the signal-to-noise ratio (SNR) margin. The fundamental Nyquist frequency for a 112G PAM4 signal sits at 28 GHz. At these extreme high frequencies, PCB traces no longer act like simple electrical connections; they behave as complex microwave transmission lines.

Overcoming the 16dB Insertion Loss Budget

In a typical 1RU 256-lane switch system, trace lengths from the switch ASIC to the front-panel module cages can range from 1.7 inches to nearly 10 inches. According to IEEE 802.3ck draft specifications, the channel budget for a practical fixed “pizza box” switch system demands a ball-to-ball Very Short Reach (VSR) insertion loss target of approximately 16dB.

If your PCB material introduces 1.5 dB of loss per inch at 28 GHz, a 10-inch trace will consume 15 dB of your budget just in raw dielectric and copper loss, leaving absolutely no margin for vias, connectors, and receiver equalization. ITEQ IT-998 solves this by driving the insertion loss down to unprecedented levels—less than 1 dB per inch at 28 GHz—making routing across large backplanes and switch motherboards mathematically possible.

The Impact of the Skin Effect and Copper Roughness

At 28 GHz, the current no longer flows through the entire cross-section of the copper trace. Due to the skin effect, the signal propagates almost entirely along the very outer skin of the copper. If the copper foil has a rough profile to aid in laminate adhesion, the high-frequency signal is forced to travel up and down the microscopic “teeth” of the copper, increasing the effective distance and drastically increasing insertion loss. ITEQ IT-998 is formulated to bond flawlessly with Hyper Very Low Profile (H-VLP) or rolled copper foils, ensuring the copper surface remains virtually perfectly smooth to minimize skin effect losses.

Core Characteristics of ITEQ IT-998 PCB Material

ITEQ IT-998 (often referred to in datasheets as IT-998G) is a next-generation, halogen-free, super ultra-low loss resin system. It is specifically engineered to replace pure PTFE (Teflon) materials in high-layer-count digital applications. While PTFE offers excellent electrical properties, it is notoriously difficult to process, prone to dimensional instability, and challenging to laminate in 30+ layer structures. ITEQ IT-998 provides PTFE-like electrical performance while maintaining the mechanical processability of an advanced epoxy/polyphenylene ether (PPE) resin blend.

Dielectric Constant (Dk) Stability

The Dielectric Constant (Dk) determines the propagation speed of the signal through the PCB. A lower Dk allows signals to travel faster. More importantly for 800G Ethernet, the Dk must remain perfectly flat across a vast frequency spectrum. ITEQ IT-998 boasts a remarkable Dk of roughly 3.0 at 28 GHz. Because the Dk remains stable from 1 GHz all the way up to millimeter-wave frequencies, designers can avoid phase dispersion, a phenomenon where different frequency harmonics of a digital pulse travel at different speeds, resulting in severe jitter and closed eye diagrams.

Dissipation Factor (Df) and Raw Insertion Loss

The Dissipation Factor (Df), or loss tangent, measures how much electromagnetic energy is absorbed by the dielectric material and converted into heat. ITEQ IT-998 achieves a Df of 0.001 at 28 GHz. To put this into perspective, standard FR-4 has a Df of around 0.020. This exceptionally low Df translates to measured insertion losses of approximately 0.73 dB/inch at 28 GHz (when paired with 6-mil traces and rolled copper in a grounded coplanar stripline configuration).

ITEQ IT-998 Material Specifications Summary

Below is a technical breakdown of the typical material specifications you can expect when utilizing this laminate in your high-speed designs.

Parameter	Test Condition / Frequency	Typical Value	Unit	Significance for PCB Engineers
Dielectric Constant (Dk)	28 GHz	3.0	–	Ensures high signal velocity and minimizes phase dispersion across wide bandwidths.
Dissipation Factor (Df)	28 GHz	0.001	–	Prevents signal energy from being absorbed by the substrate, preserving signal amplitude.
Insertion Loss (IL)	28 GHz (Simulated/Tested)	~0.73	dB/inch	Critical metric for meeting IEEE 802.3ck 16dB ball-to-ball VSR channel budgets.
Glass Transition (Tg)	DMA	>200	°C	High thermal robustness for lead-free assembly and multiple lamination cycles.
Decomposition Temp (Td)	TGA (5% weight loss)	>400	°C	Indicates excellent survivability during high-temperature reflow and rework.
Z-Axis CTE	50°C to 260°C	Very Low	ppm/°C	Reduces stress on plated through-holes (PTH), preventing via barrel cracking.
CAF Resistance	Standard Pitch	Pass	–	Prevents conductive anodic filaments, vital for dense 0.8mm or 1.0mm BGA breakouts.

ITEQ IT-998 vs. Alternative High-Speed Laminates

When designing a 32-layer 800G switch motherboard or a high-end AI GPU tray, procurement and design teams often evaluate ITEQ IT-998 alongside other premium materials. The high-speed materials market is fiercely competitive, with major players like Panasonic, TUC, and Rogers all offering ultra-low loss solutions.

ITEQ IT-998 vs. Panasonic Megtron 8

Panasonic’s Megtron series is legendary in the signal integrity community. Megtron 8 is designed for the exact same 800G and AI server markets as IT-998. Both utilize advanced hydrocarbon or PPE resin systems mixed with specialized low-Dk glass weaves. In terms of raw electrical performance, both materials hover around the 0.001 to 0.0015 Df mark at 28 GHz. The choice between IT-998 and Megtron 8 often comes down to supply chain availability, regional fabrication partnerships, and specific OEM vendor approvals. ITEQ frequently offers aggressive lead times and excellent technical field support for complex stackup validation.

ITEQ IT-998 vs. Rogers RO1200

Rogers RO1200 is a well-known benchmark for ultra-low loss performance, offering a Dk of 3.05 and a Df of 0.0017 at 10 GHz, translating to around 0.74 dB/inch insertion loss at 28 GHz. While RO1200 is exceptional, ITEQ IT-998 achieves comparable, and in some test vehicles, slightly superior insertion loss numbers (0.73 dB/inch at 28 GHz). Furthermore, ITEQ’s resin formulation is highly optimized for traditional multilayer PCB pressing, making it highly attractive for 40-layer backplanes where pure microwave materials might struggle with registration and dimensional stability.

High-Speed PCB Material Comparison for 800G Ethernet

Manufacturer	Material Name	Dk (@ 28 GHz)	Df (@ 28 GHz)	Target Application	Manufacturability (Layer Count)
ITEQ	IT-998 / IT-998G	3.0	0.001	800G Switches, AI Servers	Excellent (30+ Layers)
ITEQ	IT-988G SE	3.24	0.0014	400G/800G Systems	Excellent (30+ Layers)
Rogers	RO1200	~3.05	~0.0017*	High-Speed Digital, RF	Very Good
TUC	TU-883	~3.1	~0.0015*	Server Mainboards, Telecom	Excellent
Panasonic	Megtron 8	~3.0	~0.001	AI Clusters, 800G Optical	Excellent (30+ Layers)

(Note: Some competitor values are extrapolated from 10 GHz datasheet baseline measurements).

PCB Fabrication Realities for ITEQ IT-998

Specifying a super ultra-low loss material on a schematic is easy; successfully manufacturing a 32-layer board with it is an entirely different discipline. ITEQ IT-998 is designed with the PCB fabricator in mind, but it still requires a highly capable manufacturing partner.

High Layer Count Lamination and Registration

800G Ethernet switch motherboards and AI computing trays routinely exceed 24 to 32 layers. The board thickness can easily surpass 3.0mm, reaching up to 5.0mm for heavy backplanes. Achieving proper layer-to-layer registration requires precise scaling factors. ITEQ IT-998’s resin system exhibits predictable dimensional movement during the high-pressure lamination cycle. Fabricators must carefully manage the heating ramp rates to ensure the resin flows adequately to fill the microscopic gaps between the heavy copper planes before it cures.

Laser Drilling and Desmear Optimization

To support 112G PAM4 signals, High-Density Interconnect (HDI) structures are mandatory. You cannot route an 800G layout using simple through-hole vias due to the massive parasitic capacitance and signal reflection they cause. Designers rely heavily on blind and buried vias, often utilizing 2nd, 3rd, or even any-layer HDI configurations.

When laser drilling microvias into ITEQ IT-998, the ablation rate differs from standard FR-4 because of the specialized low-loss resin and glass formulation. Fabricators must tune their CO2 and UV laser parameters to ensure a clean via target hit without damaging the inner copper pad. Following drilling, the desmear process—which uses plasma or aggressive chemical permanganate to clean resin residue from the inner copper interconnects—must be meticulously controlled. Over-desmearing can attack the low-loss resin excessively, creating wedge voids, while under-desmearing will lead to via failure during thermal cycling.

Via-in-Pad Plated Over (VIPPO) Reliability

High pin-count ASICs and 800G optical module cages (like QSFP-DD or OSFP) require Via-in-Pad Plated Over (VIPPO) technology. Vias are drilled directly into the BGA pads, filled with epoxy, and plated flat with copper. Because IT-998 has a highly optimized Z-axis Coefficient of Thermal Expansion (CTE), it exerts minimal stress on the copper plating during the lead-free reflow process (which hits 260°C). This prevents the dreaded “pad cratering” or via barrel fatigue that plagues lower-tier materials.

Thermal Management and Reliability in AI Environments

Signal integrity is only half the battle; thermal integrity is the other. The latest generative AI server racks and 800G telecom switches generate staggering amounts of heat. An ASIC processing terabits of data per second acts like a miniature heater, conducting thermal energy directly into the PCB substrate.

ITEQ IT-998 features a high Glass Transition Temperature (Tg) exceeding 200°C (measured via DMA) and a Decomposition Temperature (Td) greater than 400°C. This ensures that the material does not soften, delaminate, or break down chemically when operating continuously in a 100°C+ ambient enclosure. Furthermore, it easily passes stringent thermal stress tests, including T288 and T300 metrics, proving it can survive the multiple high-temperature excursions required for assembling complex, double-sided server boards with thousands of surface-mount components.

Defeating Conductive Anodic Filaments (CAF)

As via pitches shrink to 0.8mm or even 0.6mm to accommodate modern silicon, the distance between adjacent drilled holes becomes microscopic. Under the influence of high voltage bias and high humidity, copper ions can migrate along the fiberglass-to-resin interface, creating a microscopic short circuit known as a Conductive Anodic Filament (CAF). ITEQ IT-998 utilizes advanced silane coupling agents that tightly bind the low-loss resin to the glass weave, effectively blocking the moisture pathways that enable CAF growth. This guarantees long-term field reliability for mission-critical data center infrastructure.

Stackup Design Strategies Using ITEQ IT-998

When you sit down with your EDA tool (like Altium, Cadence Allegro, or Mentor Xpedition) to build a stackup with ITEQ IT-998, specific strategies must be employed to extract the maximum performance from the material.

Mitigating the Fiber Weave Effect

At 28 GHz, the physical dimensions of the fiberglass weave inside the PCB substrate become a critical factor. Standard fiberglass weaves have gaps between the yarn bundles. If one trace of a high-speed differential pair routes over a dense glass bundle (higher Dk) and the other trace routes over a resin-rich gap (lower Dk), the two signals will travel at different speeds. This introduces glass weave skew, converting common-mode noise into differential noise, destroying the eye diagram.

To combat this, you should specify “spread glass” styles (such as 1067, 1078, or 1086 spread weaves) when defining your IT-998 prepregs and cores. Spread glass mechanically flattens the fiberglass bundles, creating a much more homogenous Dk environment. Additionally, routing your highest-speed 112G lanes at a slight angle (e.g., 10 to 15 degrees) relative to the PCB weave axis ensures that both traces experience the same average Dk over their length.

Managing Copper Roughness and Impedance Tolerances

Because 800G designs rely on ultra-smooth H-VLP or rolled copper, the physical adhesion between the copper and the IT-998 resin is naturally lower than with highly roughened standard copper. Designers must ensure that their trace widths and anti-pad clearances are optimized to prevent trace lifting during rework.

Furthermore, strict impedance control is mandatory. While legacy designs allowed for ±10% impedance tolerances, 800G networks demand ±5% or tighter. You must work closely with your fabrication partner to calculate the exact trace geometries based on the specific resin-content percentage of the IT-998 prepreg layers being pressed. For comprehensive guidelines on material sourcing, stackup consulting, and ensuring your fabricator can handle these tight tolerances, it is highly recommended to engage with experts early in the design phase. You can find more information and precise material handling guidelines by consulting your chosen fab or exploring specific laminate databases when sourcing ITEQ PCB for your next critical project.

Applications Beyond 800G Ethernet

While ITEQ IT-998 was practically tailor-made for the 800G optical networking market, its extreme specifications make it an ideal candidate for several other high-technology sectors.

AI and HPC Computing Trays: The transition to systems like the NVIDIA GB200 NVL72 demands massive bandwidth between the GPUs, CPUs, and NVSwitches. These compute trays utilize complex HDI architectures (e.g., 5-N-5 or 6-N-6 structures) exceeding 22 layers. The ultra-low insertion loss of IT-998 keeps these short-reach copper interconnects viable without resorting to expensive optical flyover cables for every single node.

6G Antenna Arrays and Radar: As cellular technology moves beyond 5G into the millimeter-wave spectrum of 6G, antenna-in-package (AiP) and massive MIMO array PCBs require stable dielectric performance. IT-998’s flat Dk response ensures predictable phase shifting and antenna beam steering capabilities.

Automated Test Equipment (ATE): Semiconductor probe cards and test boards must route pristine, high-frequency test signals from the tester to the silicon die. Any loss or distortion introduced by the test board can cause false failures. IT-998 provides the transparent signal path necessary for verifying next-generation silicon.

Essential Databases and Resources for PCB Engineers

When architecting a high-speed system, you shouldn’t rely on datasheets alone. Validating material performance requires access to broader industry research and simulation models. Here are some highly useful resources for engineers working with ultra-low loss materials:

IEEE 802.3ck Task Force Archives: The public archives of the IEEE contain hundreds of presentations detailing actual trace length simulations, C2M channel budgets, and real-world insertion loss measurements of materials like IT-998 and RO1200.

IPC Standards Database: Familiarize yourself with IPC-4101 (Specification for Base Materials for Rigid and Multilayer Printed Boards). Understanding the specific slash sheets that govern super ultra-low loss materials will help you write better fabrication notes.

Signal Integrity Journal: An excellent online publication featuring peer-reviewed articles on mitigating fiber weave effect, managing via stubs with back-drilling, and selecting the right copper foil profiles.

OEM Simulation Models: Always request the broadband Dk/Df tables and specific S-parameter models directly from the laminate manufacturer to input into your 3D electromagnetic solvers (like Ansys HFSS or Altair).

Frequently Asked Questions (FAQs) About ITEQ IT-998

1. What is the insertion loss of ITEQ IT-998 at 28 GHz?

Based on industry test vehicles and simulated performance using 6-mil traces and rolled copper in a grounded coplanar stripline, ITEQ IT-998 demonstrates an exceptionally low insertion loss of approximately 0.73 dB/inch at 28 GHz. This makes it highly suitable for the stringent 16dB budgets of 800G Ethernet applications.

2. Is ITEQ IT-998 compatible with standard lead-free PCB assembly?

Yes. IT-998 is designed to survive the rigors of modern RoHS-compliant, lead-free assembly. With a Glass Transition Temperature (Tg) exceeding 200°C and a Decomposition Temperature (Td) above 400°C, it easily withstands reflow oven temperatures peaking at 260°C without delamination or outgassing.

3. How does IT-998 compare to Panasonic Megtron 8?

Both materials belong to the elite “super ultra-low loss” category engineered for 800G networks and AI servers. They offer comparable Dk (around 3.0) and Df (around 0.001) values. The decision between the two usually depends on supply chain logistics, specific fabricator familiarity, and precise OEM qualifications. IT-998 is highly regarded for its stable processability in high-layer-count configurations.

4. What type of copper foil should be used with IT-998?

To fully realize the ultra-low loss benefits of the IT-998 resin system, it must be paired with Hyper Very Low Profile (H-VLP) copper or rolled annealed copper. Using standard profile copper will negate the material’s benefits, as the skin effect will force the high-frequency signal to travel across the rough microscopic teeth, drastically increasing signal loss.

5. What layer counts can be reliably manufactured with ITEQ IT-998?

Thanks to its highly optimized epoxy/PPE resin blend, IT-998 is highly processable compared to pure PTFE microwave laminates. Competent, high-end PCB fabricators routinely use it to press advanced telecom switch motherboards and AI backplanes ranging from 24 to over 40 layers, incorporating complex sequential lamination and HDI microvia structures.