Tetrafunctional Epoxy Laminate and Prepreg

FR402 consists of a modified tetrafunctional epoxy resin system engineered for multilayer applications that require performance characteristics exceeding those of difunctional epoxies.

Thermal Performance

Tg: 140°C
Td: 320°C

Electrical Performance

Dk: 4.25
Df: 0.015

Industry Approvals

IPC-4101 /21
UL - File Number E41625

The formulation of FR402 is designed to enhance throughput and accuracy of laser based Automated Optical Inspection (AOI) equipment. FR402 offers superior resistance to chemical and thermal degradation.


Product Features

  • Industry Recognition
    • UL File Number: E41625
    • RoHS Compliant
  • Processing Advantages
    • FR-4 process compatible
    • UV blocking and AOI fluorescence

Production & Manufacturing

Currently manufactured in Asia

Product Availability

  • Standard Material Offering: Laminate
    • 2 to 125 mil (0.05 to 3.2 mm)
  • Copper Foil Type
    • HTE Grade 3
  • Copper Weight
    • ½, 1 and 2 oz (18, 35 and 70 µm) available
    • Thinner copper foil available
  • Standard Material Offering: Prepreg
    • Roll or panel form
    • Tooling of prepreg panels
  • Glass Fabric Availability
    • E-glass
    • Square weave glass
    • Mechanically spread glass
Property Typical Value Units Test Method
Metric (English) IPC-TM-650 (or as noted)
Glass Transition Temperature (Tg) by DSC 140 °C 2.4.25C
Decomposition Temperature (Td) by TGA @ 5% weight loss 315 °C
Time to Delaminate by TMA (Copper removed)
A. T260
B. T288
Z-Axis CTE
A. Pre-Tg
B. Post-Tg
C. 50 to 260°C, (Total Expansion)
X/Y-Axis CTE Pre-Tg 15 ppm/°C 2.4.24C
Thermal Conductivity .36 W/m·K ASTM E1952
Thermal Stress 10 sec @ 288ºC (550.4ºF)
A. Unetched
B. Etched
Pass Pass Visual
Dk, Permittivity
A. @ 100 MHz
B. @ 500 MHz
C. @ 1 GHz
Df, Loss Tangent
A. @ 100 MHz
B. @ 500 MHz
Dk, Permittivity @ 1 GHz 0.015
Volume Resistivity
A. C-96/35/90
B. After moisture resistance
C. At elevated temperature
4.0 x 108
7.0 x 107
Surface Resistivity
A. C-96/35/90
B. After moisture resistance
C. At elevated temperature
3.0 x 106
6.0 x 106
Dielectric Breakdown >50 kV 2.5.6B
Arc Resistance 120 Seconds 2.5.1B
Electric Strength (Laminate & laminated prepreg) 29 (1100) kV/mm (V/mil)
Comparative Tracking Index (CTI) 3 (175-249) Class (Volts) UL 746A
ASTM D3638
Peel Strength
A. Low profile copper foil and very low profile copper foil all copper foil >17 μm [0.669 mil]
B. Standard profile copper
    1. After thermal stress
    2. At 125ºC (257ºF)
    3. After process solutions

1.05 (8.0)

1.45 (9.0)
1.25 (8.0)
1.45 (9.0)
N/mm (lb/inch)
Flexural Strength
A. Length direction
B. Cross direction
634 (92.0)
430 (62.3)
MPa (kpsi) 2.4.4B
Tensile Strength
A. Length direction
B. Cross direction
414 (60.0)
298 (43.2)
MPa (kpsi) ASTM D3039
Young's Modulus
A. Length direction
B. Cross direction
ksi ASTM D790-15e2
Moisture Absorption 0.3 %
Flammability (Laminate & laminated prepreg) V-0 Rating UL 94
Relative Thermal Index (RTI) 130 °C UL 796
The data, while believed to be accurate and based on analytical methods considered to be reliable, is for information purposes only. Any sales of these products will be governed by the terms and conditions of the agreement under which they are sold.


Visit our site for more details.
A: Initial release - 4/17
B: Corrected units for Flexural and Tensile Strength - 8/18
C: Change MOT to RTI 5/19

Resource Title & Summary Date Updated
FR402 Processing Guide 06/23/2020
FR402 Prepreg Safety Data Sheet 07/21/2020
FR402 Laminate Safety Data Sheet 07/21/2020
FR402 Laminate RoHS Declaration 11/01/2022
FR402 Prepreg RoHS Declaration 11/01/2022


Laminate & Prepreg Manufacturing

This presentation describes the process of laminate and prepreg manufacturing.

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Laminates, Prepreg, & PCB Materials

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