TU-865 8-Layer 4.5mm Heavy Copper PCB – High Current & Harsh Environment Applications

1. Introduction to TU-865 Heavy Copper PCB

TU-865 is a high-performance Tg200 material made of epoxy resin and E-glass fabric. It is a halogen-free material designed for harsh environments, high reliability applications, and superior electrical performance. TU-865 achieves UL94V-0 flammability rating by incorporating phosphorus and nitrogen compounds.

This 8-layer heavy copper PCB features 10 oz (350 μm) copper on every layer, designed for high current carrying capacity and excellent thermal management. The material is compatible with AOI processes and exhibits UV-block characteristics. TU-865P prepreg is designed for use with TU-865 laminate for multilayer board construction.

TU-865 laminates exhibit superior chemical resistance, dimensional stability, and moisture resistivity for lead-free soldering assembly and CAF resistance, making them ideal for boards that need to survive severe thermal cycling or excessive assembly work.

2. Key Features of TU-865

• Halogen, antimony, and red phosphorus free

• High Tg (DMA >170°C, DSC >340°C)

• Mid-loss performance category (Df 0.010-0.014 @ 1-10 GHz)

• Low CTE (Z-axis CTE <3.0%)

• Excellent moisture resistance (<0.13% water absorption)

• Lead-free processing compatible

• Anti-CAF capability

• Environmental friendly material

• T260 >30 min, T288 >15 min, T300 >2 min

• Flammability: UL 94V-0

• Maximum operating temperature: 130°C

3. Benefits of TU-865 Heavy Copper PCB

• High current carrying capacity with 10 oz copper on all layers

• Excellent thermal dissipation for power electronics

• Survives severe thermal cycling and excessive assembly work

• Superior chemical resistance and dimensional stability

• Ideal for automotive and harsh environment applications

• Halogen-free and environmentally friendly

• Compatible with lead-free soldering processes

4. TU-865 PCB Construction Details

5. PCB Stackup (8-Layer Heavy Copper Structure)

• L1 (GTL - Top Copper): 10 oz (0.35 mm)

• Prepreg: TU-865P – 0.20 mm

• L2 (Inner Copper): 10 oz (0.35 mm)

• Prepreg: TU-865P – 0.20 mm

• L3 (Inner Copper): 10 oz (0.35 mm)

• Core: TU-865 – thickness TBD

• L4 (Inner Copper): 10 oz (0.35 mm)

• Prepreg: TU-865P – 0.20 mm

• L5 (Inner Copper): 10 oz (0.35 mm)

• Prepreg: TU-865P – 0.20 mm

• L6 (Inner Copper): 10 oz (0.35 mm)

• Core: TU-865 – thickness TBD

• L7 (Inner Copper): 10 oz (0.35 mm)

• Prepreg: TU-865P – 0.20 mm

• L8 (GBL - Bottom Copper): 10 oz (0.35 mm)

• Total Pressed Thickness: ~4.5 mm (nominal)

Note: Core thicknesses adjusted to achieve 4.5mm total thickness.

6. PCB Special Features

• Blind Vias: Layer-to-layer interconnections without full stack penetration

• Buried Vias: Internal layer interconnections

• Half-holes (Castellation): Edge plating for module stacking

• Conductive Copper Paste Filling: All vias filled with conductive copper paste for thermal and electrical continuity

• Heavy Copper (10 oz): All 8 layers with 350 μm copper thickness

7. Primary Application Areas

• Automotive electronics (harsh environments)

• Servers and data centers

• Telecom and base station equipment

• High current power supplies

• Industrial power electronics

• Battery management systems (BMS)

• Motor drive controllers

• High reliability industrial controls

8. Quality Assurance

• Artwork supplied: Gerber RS-274-X

• Accepted standard: IPC-Class-2 (typical)

• UL File Number: E189572

• UL Designation: ANSI Grade FR-4.1

• IPC-4101E Type: /127, /128, /130

• IPC-4101E/130 QPL Certified

• Worldwide availability

9. TU-865 High Tg Laminate – Product Introduction

TU-865 Tg200 material is made of epoxy resin and E-glass fabric. It is a halogen-free material designed to have features for harsh environment, high reliability application and superior electrical performance at the same time. TU-865 achieves flammability class of UL94V-0 by incorporating phosphorus and nitrogen compounds. The material is compatible with the AOI process and exhibits UV-block characteristic.

TU-865P is prepreg designed for use with TU-865 laminate for making multilayer printed wire boards. TU-865 is also available for single/double sided application. This series of green materials eliminates the use of halogenated resins with excellent performance due to potential hazardous effects from environmental concerns.

These products are suitable for boards that need to survive severe thermal cycling, or to experience excessive assembly work. TU-865 laminates also exhibit superior chemical resistance, dimensional stability and moisture resistivity for lead-free soldering assembly and CAF resistance.

10. Features and Benefits

• Halogen, antimony, and red phosphorus free

• High Tg for thermal reliability

• Mid-loss performance for signal integrity

• Low CTE for dimensional stability

• Excellent moisture resistance

• Lead-free processing compatible

• Anti-CAF capability for long-term reliability

• Environmentally friendly

11. TU-865 Data Sheet

12. Typical Applications

• Automotive electronics (harsh environments)

• Servers and data centers

• Telecom and base station equipment

• High current power supplies

• Industrial power electronics

• Battery management systems (BMS)

• Motor drive controllers

• High reliability industrial controls

• Power distribution boards

• Electric vehicle (EV) power systems

13. Standard Availability – TU-865

• 1/3 oz to 12 oz copper foil

• Available in roll or panel form

• Glass styles: 106, 1080, 2113, 2116, 1506, 7628

• IPC-4101E Type: /127, /128, /130

• IPC-4101E/130 Validation Services QPL Certified

• UL Designation: ANSI Grade FR-4.1

• UL File Number: E189572