High CTI, High RTI Halogen-free multi-layer circuit board materials | R-3566D

High CTI, High RTI Halogen-free multi-layer circuit board materials R-3566D


  1. Supports high heat resistance and high withstand voltage required for xEV and Industrial devices
  2. Support in reduction of PCB board size due to reduced creepage distances by excellent tracking resistance (PLC=0)
  3. Halogen-free material reducing environmental impact

Circuit Board Materials

  • Part Number

Laminate R-3566D
Prepreg R-3551D

  • Application
  • Detailed use
On Board Charger, DC/DC Converter, Inverter, In-Wheel Motor
EV Charging Stand, HV Control Unit, PV Module


CTI≥600V*¹ PLC=0
*¹ Measurement by ASTM method
UL FR-15.1, RTI 150°C*²
*² 0.63mm or more
High voltage CAF resistance

Positioning of R-3566D

Positioning of R-3566D

Through-hole reliability

Through-hole reliability

Insulation reliability

Insulation reliability

General properties

Item Test method Condition Unit Halogen-free
Our conventional
Glass transition temp. (Tg) DSC A °C 175 148
TMA 170 145
Thermal decomposition temp. (Td) TGA A °C 355 350
T288 (with copper) IPC-TM-650 A min 10 3
CTE z-axis α1 IPC-TM-650 2.4.24 A ppm/°C 40 40
α2 180 180
RTI* UL Method C-48/23/50 °C 150 130
PLC* 0 1
Peel strength 1oz (35µm) IPC-TM-650 2.4.8 A kN/m 1.6 1.8
Flammability UL Method C-48/23/50 94V-0 94V-0

The sample thickness is 0.8mm.
* This sample thickness is 1.6mm.

Our Halogen-free materials are based on JPCA-ES-01-2003 standard and others.
Contain; Chlorine:≤0.09wt%(900ppm), Bromine:≤0.09wt%(900ppm),

The above data are typical values and not guaranteed values.

For your study ! For your study !

To extend the cruising range of a BEV or to improve the power output of an Industrial Device, SiC and GaN semiconducters are used for related electronic components like DC/DC converter or Inverter. Those devices are able to work at higher voltages and also higher temperatures. On the other hand, the reductions of size and weight are common topics on every automotive part.

The CTI (comparative tracking index) and the RTI (Reference Temperature Index) are important base material characteristics to support such market trends.

Relationship between creepage distance and CTI
CTI is used to assess the relative resistance of insulating materials to tracking. It is one of the factors that influences the layout of the creepage distance on a PCB (Fig.1).
Fig.1 Creepage distance
It is possible to reduce the creepage distance on a board, at the same voltage, if a material with a higher CTI is used. (Fig.2)
Fig.2 General relationship between Comparative Tracking Index (CTI) and creepage distance
Relationship between RTI* and MOT
In former Times FR-4 has been dedicated to a max. RTI (Reference Temperature Index) of a maximum of 130°C. Because of higher temperature requirements on PCB application and its components (like GaN and SiC), a new class of FR Material has been introduced. The FR 15 class.

Materials inside this class are showing a max. RTI of 150°C.
If the final equipment has to fulfil a MOT (Maximum Operation Temperature) of 150°C, you must use base materials with a minimum RTI of 150°C.

* RTI (Relative Thermal Index)
An indicator of the ability of a material to retain certain physical properties (physical, electrical, etc.) when exposed to high temperatures for extended periods of time.
The heat is on!

R-3566D, a high CTI and high RTI material, has an excellent tracking resistance and excellent heat resistance. This material is suitable for various applications that require high voltage and downsizing, such as automotive and industrial applications.

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