KB-3200G is Kingboard's halogen-free low-loss laminate, officially classified as "Halogen-Free / High Tg / Low Loss". With verified Dk 4.1 and Df 0.0075 at 1 GHz, Tg 178 °C (DSC) / 193 °C (DMA), Td 387 °C, and Z-CTE 1.8 %, it targets the infrastructure backbone of modern data centers and telecom networks: server motherboards, network switch boards, base station equipment, backplanes, and high-complexity multilayer PCBs. KB-3200G delivers roughly 40 % lower dielectric loss than standard FR-4 (Df ≈ 0.012) while maintaining halogen-free compliance, excellent thermal endurance, and anti-CAF reliability — all backed by Kingboard's unmatched production scale as the world's largest CCL manufacturer.
KB-3200G sits between Kingboard's standard halogen-free materials (HF-140 / HF-170, Df ≈ 0.011) and the true ultra-low-loss class (Megtron 6 / 7, Df < 0.005). This makes it the cost-optimized choice for 10 G–25 G NRZ and moderate 56 G PAM4 digital interfaces — the signaling rates that dominate today's server, switch, and telecom infrastructure. For designs that need better signal integrity than standard FR-4 but do not require a Megtron-class investment, KB-3200G provides the optimal balance of performance, cost, and supply-chain security.
In This Guide
- Where KB-3200G Sits in the Low-Loss Material Landscape
- KB-3200G Verified Technical Specifications
- Server, Switch, Backplane, and HPC Applications
- KB-3200G vs KB-6167GLD vs KB-6167GMD: Choosing the Right Low-Loss Grade
- Hybrid Stackup Architecture for Multi-Speed Designs
- PCB Fabrication Requirements for Low-Loss Performance
- Kingboard's Next-Generation Low-Loss Material Roadmap
- How to Order KB-3200G PCBs from APTPCB
Where KB-3200G Sits in the Low-Loss Material Landscape
KB-3200G occupies the low-loss tier within Kingboard's halogen-free product family — a meaningful step up from standard and mid-loss FR-4, but distinct from the ultra-low-loss materials used for the fastest SerDes interfaces:
| Material | Manufacturer | Df @1 GHz | Dk @1 GHz | Loss Tier | Target Application |
|---|---|---|---|---|---|
| KB-6167GMD | Kingboard | 0.008 ✓ | 4.1 ✓ | Mid-Loss | General digital ≤ 10 G |
| KB-3200G | Kingboard | 0.0075 ✓ | 4.1 ✓ | Low-Loss | Server / backplane / HPC |
| KB-6167GLD | Kingboard | 0.006 ✓ | 3.9 ✓ | Low-Loss | 25 G NRZ / 56 G PAM4 |
| Megtron 4 (R-5775K) | Panasonic | ~0.005 | ~3.8 | Low-Loss | 25 G–56 G SerDes |
| Megtron 6 (R-5775N) | Panasonic | ~0.003 | ~3.4 | Ultra-Low-Loss | 112 G PAM4 |
The performance gap between KB-3200G (Df 0.0075) and true ultra-low-loss materials like Megtron 6 (Df ≈ 0.003) is roughly 2.5×. This means KB-3200G is not a direct Megtron 6 alternative — it serves a different application tier. Within the halogen-free low-loss category, however, KB-3200G offers the unique advantage of Kingboard's manufacturing scale, ensuring capacity assurance and competitive pricing for high-volume server and telecom programs.
KB-3200G Verified Technical Specifications
All values below are verified from the official Kingboard PDF datasheet (KB-3200G / PP-KB3200G). IPC-4101E/130. Classification: Halogen-Free / High Tg / Low Loss. Specimen thickness: 1.0 mm (#2116 × 10). UL file: E123995.
Thermal Properties
| Property | Verified Value ✓ | Test Method |
|---|---|---|
| Glass Transition (Tg, DSC) | 178 °C ✓ | IPC-TM-650 2.4.25 |
| Glass Transition (Tg, DMA) | 193 °C ✓ | IPC-TM-650 2.4.24.4 |
| Decomposition Temperature (Td, TGA 5 %) | 387 °C ✓ | IPC-TM-650 2.4.24.6 |
| T-260 (time to delamination) | > 60 min ✓ | IPC-TM-650 2.4.24.1 |
| T-288 (time to delamination) | > 60 min ✓ | IPC-TM-650 2.4.24.1 |
| Thermal Stress (float 288 °C) | ≥ 240 sec ✓ | IPC-TM-650 2.4.13.1 |
| Z-axis CTE (50–260 °C) | 1.8 % ✓ | IPC-TM-650 2.4.24 |
| Z-axis CTE α1 (below Tg) | 45 ppm/°C ✓ | IPC-TM-650 2.4.24 |
| Z-axis CTE α2 (above Tg) | 200 ppm/°C ✓ | IPC-TM-650 2.4.24 |
| X/Y CTE (40–125 °C) | 12 / 15 ppm/°C ✓ | IPC-TM-650 2.4.24 |
| Flammability | V-0 ✓ | UL 94 |
| Halogen-Free | Yes ✓ | IEC 61249-2-21 |
Electrical Properties
| Property | Verified Value ✓ | Test Method |
|---|---|---|
| Dk @1 GHz | 4.1 ✓ | IEC 61189-2-721 (RC 50 %) |
| Dk @10 GHz | 4.0 ✓ | IEC 61189-2-721 (RC 50 %) |
| Df @1 GHz | 0.0075 ✓ | IEC 61189-2-721 (RC 50 %) |
| Df @10 GHz | 0.0085 ✓ | IEC 61189-2-721 (RC 50 %) |
| CTI | ≥ 175 V ✓ | IEC 60112 |
| Dielectric Breakdown | ≥ 45 kV ✓ | IPC-TM-650 2.5.6 |
| Arc Resistance | 122 sec ✓ | IPC-TM-650 2.5.1 |
| Anti-CAF | Yes ✓ | — |
Mechanical Properties
| Property | Verified Value ✓ | Test Method |
|---|---|---|
| Peel Strength (float 288 °C) | 1.30 N/mm ✓ | IPC-TM-650 2.4.8 |
| Flexural Strength (MD) | 580 N/mm² ✓ | IPC-TM-650 2.4.4 |
| Flexural Strength (XD) | 490 N/mm² ✓ | IPC-TM-650 2.4.4 |
| Water Absorption | 0.11 % ✓ | IPC-TM-650 2.6.2.1 |
Key dielectric context: KB-3200G's Dk 4.1 and Df 0.0075 at 1 GHz represent roughly 40 % lower dielectric loss than standard halogen-free FR-4 (Dk ≈ 4.6, Df ≈ 0.012). These values place it firmly in the low-loss tier, not the ultra-low-loss tier. For applications requiring Df < 0.005 — such as 112 G PAM4 or PCIe Gen 6 — specify KB-6167GLD (Df 0.006) or external ultra-low-loss materials instead.
Server, Switch, Backplane, and HPC Applications
The official Kingboard datasheet lists KB-3200G's target applications explicitly: server, switch, base station, backplane, high-performance computing, network and telecom, and high-complexity multi-layers.
Server Motherboards
Modern server platforms running 10 G–25 G NRZ interfaces (PCIe Gen 4, DDR5, 25 GbE) benefit directly from KB-3200G's reduced dielectric loss. The ≈ 40 % Df improvement over standard FR-4 translates to roughly 1.5–2 dB less insertion loss on a typical 8-inch server trace at 12.5 GHz Nyquist — meaningful margin improvement without the cost of ultra-low-loss substrates. Tg 178 °C (DSC) / 193 °C (DMA) and T-288 > 60 min provide the thermal reliability multi-year server operation demands.
Network Switch Boards
Data center top-of-rack and spine switches with 25 G NRZ or early 56 G PAM4 SerDes represent KB-3200G's sweet spot. The 1.8 % Z-CTE ensures via reliability in 16–24-layer boards, and halogen-free compliance meets the environmental requirements increasingly mandated by hyperscale operators.
Telecom Base Station and Backplane
Base station equipment and telecom backplanes require decades of service life under temperature cycling. KB-3200G's combination of Td 387 °C, T-260 / T-288 > 60 min, and anti-CAF capability delivers the long-term reliability these telecom applications demand, with low-loss performance supporting the rising data rates of 5G fronthaul and backhaul interfaces.
High-Performance Computing (HPC)
HPC systems with dense processor interconnects benefit from KB-3200G's low-loss properties and excellent Z-CTE for high-layer-count builds. The halogen-free formulation meets institutional procurement requirements at major research facilities and government installations.
KB-3200G vs KB-6167GLD vs KB-6167GMD: Choosing the Right Low-Loss Grade
| Property | KB-6167GMD ✓ | KB-3200G ✓ | KB-6167GLD ✓ |
|---|---|---|---|
| Classification | Mid-Loss | Low-Loss | Low-Loss |
| Tg (DSC / DMA) | 178 / 190 °C | 178 / 193 °C | — / 220 °C (DMA) |
| Td | 387 °C | 387 °C | 409 °C |
| Z-CTE (50–260 °C) | 2.1 % | 1.8 % | 1.8 % |
| Dk @1 GHz | 4.1 | 4.1 | 3.9 |
| Dk @10 GHz | 4.0 | 4.0 | 3.8 |
| Df @1 GHz | 0.008 | 0.0075 | 0.006 |
| Df @10 GHz | 0.009 | 0.0085 | 0.007 |
| Anti-CAF | Yes | Yes | Yes |
| Halogen-Free | Yes | Yes | Yes |
| Relative Cost | 1.2× | 1.5× | 1.8× |
| Best For | General digital ≤ 10 G | Server / backplane 10–25 G | 25 G NRZ / 56 G PAM4 |
Choose KB-3200G when: You need halogen-free low-loss for server, switch, or backplane applications at 10 G–25 G NRZ, and the extra cost of KB-6167GLD is not justified by channel budget requirements.
Choose KB-6167GLD when: Your design runs 25 G NRZ or 56 G PAM4 with tight channel budgets, or requires the additional thermal margin of Tg 220 °C (DMA) and Td 409 °C.
Choose KB-6167GMD when: Standard digital speeds (≤ 10 G) and cost optimization are the primary drivers. The small Df gap from KB-3200G (0.008 vs 0.0075) is insignificant at lower frequencies.
Hybrid Stackup Architecture for Multi-Speed Designs
Modern switch and server boards combine multiple signal-speed classes. A tiered-material approach optimizes cost per layer:
| Layer Type | Material | Rationale |
|---|---|---|
| High-speed signal pairs (25 G+) | KB-6167GLD or KB-3200G prepreg | Lowest Df for critical lanes |
| Moderate-speed signals (≤ 10 G) | KB-6167GMD | Mid-loss sufficient, lower cost |
| Control / management signals | HF-170 or KB-6167F cores | Standard performance adequate |
| Power / Ground planes | KB-6167F cores | Thermal reliability, lowest cost |
A 20-layer switch board might use KB-3200G on four high-speed dielectric layers, KB-6167GMD on four moderate-speed layers, and KB-6167F for the remaining ground/power layers — saving 25–35 % versus full KB-3200G construction while maintaining performance where it matters.
Our stackup design service handles multi-material impedance modeling with per-layer Dk assignments. The Dk difference between KB-3200G (Dk 4.0 at 10 GHz) and KB-6167F (Dk ≈ 4.6) layers requires careful impedance calculation — the same trace width produces roughly 8 % different impedance on different dielectric layers.
PCB Fabrication Requirements for Low-Loss Performance
KB-3200G achieves its full performance advantage only when fabrication practices match the material capability:
Copper foil: HVLP (Rz ≤ 3 µm) is recommended to realize the dielectric loss improvement. At 10+ GHz, standard HTE copper adds conductor loss that can negate the Df improvement over standard FR-4. Specify copper grade explicitly in fabrication drawings.
Backdrilling: For through-hole via stubs on layers carrying high-speed signals, backdrill to minimize stub resonance. Target < 10 mil stub length for 25 G NRZ applications. Our fabrication process achieves consistent backdrill depth control within ± 2 mils.
Glass weave mitigation: For differential pairs at 10+ Gbps on KB-3200G, consider spread-glass (NE-glass) or rotated routing angles (7–15° from weave axis) to mitigate the fiber weave effect. This adds roughly 10 % to prepreg cost but improves differential skew performance.
Press profile control: Low-loss resin systems require precise cure conditions. Temperature ramp control (± 2 °C) and adequate cure at peak temperature ensure complete cross-linking for stable dielectric performance. Our dedicated press profiles for KB-3200G are developed and maintained through qualification testing.
Insertion loss testing: S-parameter measurement on dedicated test coupons verifies that the fabricated board achieves the expected low-loss performance. Our quality system includes VNA-based insertion loss testing with SPC tracking for KB-3200G production.
Kingboard's Next-Generation Low-Loss Material Roadmap
Kingboard's product roadmap extends beyond KB-3200G into the next generation of low-loss and ultra-low-loss materials. Publicly announced products include KB-5200G, KB-6200G, KB-7200G, and KB-8200G, targeting progressively lower Df values to address the industry's migration toward 56 G, 112 G, and 224 G PAM4 interfaces.
KB-6200G has already received REACH and UL certification, signaling near-term commercial availability. These next-generation products are expected to extend Kingboard's reach into the ultra-low-loss space currently dominated by Panasonic Megtron 6/7 and similar materials — a tier that KB-3200G does not yet address.
APTPCB qualifies new Kingboard materials as they become commercially available. For designs targeting future production with next-generation interfaces, contact our engineering team for the latest material qualification status and design support for early adoption programs.
How to Order KB-3200G PCBs from APTPCB
Submit your design with signal-speed requirements and interface specifications. We verify KB-3200G suitability, model hybrid stackup options with per-layer material optimization, and provide comprehensive DFM and signal integrity feedback. For complete one-stop fabrication and assembly, we quote the full project including KB-3200G material, recommended copper foils, backdrilling, and insertion loss testing — all in a single integrated quote.
For high-volume server and telecom production, Kingboard's manufacturing scale ensures consistent material supply. APTPCB maintains KB-3200G qualification and can pre-stock based on your production forecast for the shortest lead times.