2. PCB Basic Specification Table

Specification Item	Detailed Parameters
PCB Layer Count	12-layer Multilayer Board
Base Material	TG200 FR-4 + TU-872 SLK Low Loss Material
Finished Board Thickness	1.68mm
Outer Layer Copper Weight	1oz
Inner Layer Copper Weight	0.5oz
Surface Treatment	Immersion Gold
Solder Mask & Printing	Matte Green Solder Mask, White Silk Screen
Board Dimension	155mm × 79.5mm (1PCS, Including Process Edge)
Special Processes	Full Via Resin Plugging & Electroplating Filling, Multi-layer Precision Impedance Control
Impedance Control Parameters	TOP: 90ohm, 100ohm differential (4.9mil/5.5mil), 50ohm single-end (7mil); L3: 90ohm, 100ohm differential (4.5mil/4.7mil), 50ohm single-end (6mil); L5: 100ohm differential (5mil/6mil), 50ohm single-end (9mil); L10: 85ohm (8mil); L12: 100ohm differential (5mil/5mil), 50ohm single-end (7mil)

3. PCB Stackup Structure

This high-spec 12-layer multilayer PCB adopts a scientific and stable stackup structure adopting premium TU-872 SLK low-loss dielectric material with inherent TG200 high-Tg FR-4 properties. The layered configuration strictly follows industrial high-speed circuit design standards, realizing balanced electrical performance, structural stability and precise impedance control. The reasonable layer layout effectively isolates signal interference, guarantees consistent impedance characteristics of each transmission line, and adapts to high-speed and high-frequency working conditions. The detailed stackup structure is listed as follows:

This 12-layer PCB adopts a scientific hybrid dielectric stackup design combining TU-872 SLK low-loss dielectric material and TG200 high-Tg FR-4 dielectric material, achieving perfect balance between high-speed signal performance and overall structural stability. The overall layer configuration starts with a 1oz outer copper TOP layer with precise impedance control, paired with a TU-872 SLK low-loss dielectric layer. It is followed by a 0.5oz L2 inner copper layer and multiple groups of TG200 FR-4 dielectric layers matched with 0.5oz inner copper layers including L3, L4, L5, L6, L7, L8 and L9. Among them, the L3, L5 and L10 inner copper layers are designed with professional impedance control to meet high-speed transmission requirements. After the 0.5oz impedance-controlled L10 copper layer, the stackup adopts TU-872 SLK low-loss dielectric layers again, matching with the 0.5oz L11 inner copper layer and finally ending with a 1oz impedance-controlled L12 outer copper layer. This alternating stackup structure optimizes high-frequency signal transmission, effectively isolates signal crosstalk, ensures stable impedance performance of key signal layers, and greatly improves the structural flatness and thermal stability of the whole board.

4. TU-872 SLK Basic Material Introduction

TU-872 SLK is a high-performance TG200-grade modified epoxy FR-4 dielectric material reinforced with regular woven E-glass fabric, professionally designed for high-speed, low-loss and high-frequency multilayer PCB applications. Optimized with allyl network forming compounds, this upgraded FR-4 substrate effectively improves material toughness, dimensional stability and overall flatness compared with conventional FR-4 materials. The material supports eco-friendly lead-free reflow processes and is fully compatible with standard FR-4 production procedures, enabling mass industrial manufacturing with stable and consistent quality.

5. TU-872 SLK Electrical Performance

The material delivers outstanding low-loss electrical performance with a dielectric constant lower than 4.0 and an ultra-low dissipation factor below 0.010. Its Dk and Df parameters remain stable and flat across a wide frequency and temperature range, greatly reducing high-frequency signal attenuation and crosstalk to ensure excellent signal integrity for high-speed circuit designs.

6. TU-872 SLK Processing & Mechanical Advantages

TU-872 SLK features excellent process compatibility and mechanical performance. It is fully compatible with traditional modified FR-4 production workflows, requiring no special processing adjustment and supporting high-volume manufacturing. The material provides improved Z-axis thermal expansion performance, superior dimensional stability, uniform thickness and excellent flatness. It also supports multiple lamination cycles and guarantees precise layer alignment for high-layer-count multilayer PCBs.

7. TU-872 SLK Standard Product Specifications

TU-872 SLK supports abundant standardized and customizable specifications to fit diverse PCB design demands. Laminate thickness ranges from 0.05mm (0.002”) to 1.58mm (0.062”), available in sheet or panel forms. Copper foil cladding options cover 1/3oz to 5oz for double-sided and build-up structures. Multiple glass fabric styles including 106, 1080, 3313 and 2116 are optional, and prepreg materials are supplied in roll or panel formats for flexible production matching. The material possesses outstanding environmental adaptability and long-term operational reliability. It offers excellent moisture resistance and low water absorption, maintaining stable performance under high-temperature and high-humidity working conditions. With superior chemical resistance, thermal stability and strong CAF resistance, TU-872 SLK effectively prevents layer delamination, circuit failure and conductive anodic filament growth. It is fully lead-free reflow compatible and ensures reliable through-hole structure and soldering performance.

8. TU-872 SLK Reliability & Environmental Resistance

The material possesses outstanding environmental adaptability and long-term operational reliability. It offers excellent moisture resistance and low water absorption, maintaining stable performance under high-temperature and high-humidity working conditions. With superior chemical resistance, thermal stability and strong CAF resistance, TU-872 SLK effectively prevents layer delamination, circuit failure and conductive anodic filament growth. It is fully lead-free reflow compatible and ensures reliable through-hole structure and soldering performance. TU-872 SLK complies with a full set of international industrial standards and authoritative certifications. It meets IPC-4101E specifications including /29, /99, /101 and /126, and obtains IPC-4101E/126 QPL certification. It is UL certified (UL File Number: E189572), rated FR-4.0 grade with 94V-0 flammability resistance, and supports a maximum continuous operating temperature of 130°C, meeting global industrial safety and environmental requirements.

9. TU-872 SLK Industry Certification & Standards

TU-872 SLK complies with a full set of international industrial standards and authoritative certifications. It meets IPC-4101E specifications including /29, /99, /101 and /126, and obtains IPC-4101E/126 QPL certification. It is UL certified (UL File Number: E189572), rated FR-4.0 grade with 94V-0 flammability resistance, and supports a maximum continuous operating temperature of 130°C, meeting global industrial safety and environmental requirements. TU-872 SLK supports abundant standardized and customizable specifications to fit diverse PCB design demands. Laminate thickness ranges from 0.05mm (0.002”) to 1.58mm (0.062”), available in sheet or panel forms. Copper foil cladding options cover 1/3oz to 5oz for double-sided and build-up structures. Multiple glass fabric styles including 106, 1080, 3313 and 2116 are optional, and prepreg materials are supplied in roll or panel formats for flexible production matching.

 

10. TU-872 SLK Datasheet

Property	Typical Value	Conditioning	IPC-4101 /126 Spec
Thermal Properties
Tg (DMA)	> 170°C	E-2/105	—
Tg (DSC)	> 170°C	E-2/105	—
Tg (TMA)	> 170°C	E-2/105	—
Td (TGA)	> 340°C	E-2/105	—
CTE x-axis	N/A	E-2/105	N/A
CTE y-axis	N/A	E-2/105	N/A
CTE z-axis total expansion	<3.0%	E-2/105	<3.0%
Thermal Stress (Solder Float, 288°C)	> 10 sec, no delamination	A	> 10 sec
T260 (TMA)	> 30 min	E-2/105	> 30 min
T288 (TMA)	> 15 min	E-2/105	> 15 min
T300 (TMA)	> 2 min	E-2/105	> 2 min
Flammability	94V-0	E-24/125	94V-0
Electrical Properties
Permittivity @1GHz (SPC method/4291B)	< 5.2	E-2/105	< 5.2
Permittivity @5GHz (SPC method)	—	E-2/105	—
Permittivity @10GHz (SPC method)	—	E-2/105	—
Loss Tangent @1GHz (SPC method/4291B)	< 0.035	E-2/105	< 0.035
Loss Tangent @5GHz (SPC method)	—	E-2/105	—
Loss Tangent @10GHz (SPC method)	—	E-2/105	—
Volume Resistivity	> 10¹⁰ MΩ·cm	C-96/35/90	> 10⁶ MΩ·cm
Surface Resistivity	> 10⁸ MΩ	C-96/35/90	> 10⁴ MΩ
Electric Strength	> 40 KV/mm	A	> 30 KV/mm
Dielectric Breakdown	> 50 KV	A	N/A
Mechanical Properties
Young’s Modulus (Warp / Fill Direction)	N/A	A	N/A
Flexural Strength (Lengthwise)	> 60,000 psi	A	> 60,000 psi
Flexural Strength (Crosswise)	> 50,000 psi	A	> 50,000 psi
Peel Strength (1.0 oz. RTF Cu foil)	> 4 lb/in	A	> 4 lb/in
Water Absorption	0.13 %	E-1/105+D-24/23	< 0.5 %

 

11. TU-872 SLK Application Fields

Relying on its high-speed low-loss electrical properties, excellent thermal stability, high dimensional accuracy and lead-free process compatibility, TU-872 SLK is widely used in high-end industrial and commercial electronic equipment. It is highly suitable for radio frequency and high-frequency circuit devices, high-performance computing backplanes, communication line cards and data storage hardware. The material is also extensively applied in servers, telecommunication infrastructure, base station equipment and office router products. As a cost-effective high-performance modified FR-4 substrate, it is the preferred material for high-layer-count, high-reliability and low-loss multilayer PCB products in communication, computing and RF electronic industries.

 

12. Summary

This 12-layer 1.68mm high-precision PCB adopts premium TU-872 SLK TG200 modified FR-4 low-loss dielectric material, featuring stable high-speed electrical performance and excellent structural reliability. With differentiated inner and outer copper thickness design, immersion gold surface finishing and matte green solder mask treatment, the board delivers superior surface durability and circuit stability. Equipped with full via resin plugging and multi-layer customized precision impedance control technology, this multilayer PCB maintains ultra-stable signal integrity and low signal crosstalk in high-frequency and high-speed transmission scenarios. Supported by TU-872 SLK’s outstanding moisture resistance, CAF resistance, thermal stability and complete international certifications, the product fully meets the high-reliability manufacturing requirements of communication equipment, server computing systems and RF electronic devices, complying with European and American industrial quality standards.

 

Tags: 12-layer 1.68mm PCB,  TU-872 SLK PCB, High Speed PCB, Immersion Gold PCB, High TG200 PCB, Impedance Control PCB, Multilayer PCB, Resin Plug Via PCB, High Frequency PCB, Server Communication PCB, Computing Backplane PCB, RF Circuit PCB, Lead Free FR4 PCB, High Precision PCB