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Rogers DiClad 870 Microwave PCB Materials

 

 

Introduction

 Welcome back to our channel. In today’s video, we’ll be discussing a type of high frequency laminate that features a lower dielectric constant --- Rogers DiClad 870 microwave PCB materials.

 

DiClad 870 is a type of Rogers laminate that is made with woven fiberglass reinforced, PTFE-based composites. This unique composition allows for a stable, lower dielectric constant by using fewer plies of woven fiberglass and a higher ratio of PTFE content. As a result, DiClad 870 material can support wider line widths for lower insertion loss.

 

To learn more about DiClad 870 laminate, let’s see the data sheet.

 

DiClad 870 Typical Properties

DiClad 870 is a high frequency PCB material that offers excellent electrical properties. It has a dielectric constant of 2.33 at both 1 MHz and 10 GHz, with a low dissipation factor of 0.0009 at 1 MHz and 0.0013 at 10 GHz.

 

It also has a thermal coefficient of dielectric constant of -161 ppm/°C from -10°C to +140°C.

 

DiClad 870 laminate has a high volume resistivity of 1.5 x 10^9 MΩ-cm and a surface resistivity of 3.4 x 10^7 MΩ.

 

Additionally, it shows an arc resistance of greater than 180 seconds, tested according to ASTM D-495 using the D48/50 method. This is an impressive result.

 

Rogers DiClad 870 high frequency circuit materials shows a dielectric breakdown voltage of greater than 45 kV, tested according to ASTM D-149 using the D48/50 method. This is another impressive result as well.

 

When it comes to mechanical properties, DiClad 870 has a high peel strength of 14 lbs. per inch after thermal stress.

 

It also has impressive tensile modulus, tensile strength, compressive modulus, and flexural modulus at 23°C.

 

DiClad 870 also has great thermal properties. It has a low coefficient of thermal expansion of 17 ppm/°C (X axis), 29 ppm/°C (Y axis), and 217 ppm/°C (Z axis) from 0°C to 100°C.

 

However, the thermal conductivity is only 0.257 W/mK at 100°C.

 

It meets the requirements of UL94-V0 flammability rating, which makes it a safe material to use.

 

A final aspect we'll examine is the physical properties.

 

DiClad 870 shows a density of 2.26 g/cm3 at 23°C, tested according to ASTM D-792 Method A. This is a relatively high density, which suggests that DiClad 870 is a dense and sturdy material.

 

Water absorption rate of 0.02% is low, indicating that DiClad 870 is a material that does not absorb water easily.

 

Then, last one is outgassing characteristics.

 

Outgassing refers to the release of volatile materials from a material during use.

 

The data shows that DiClad 870 has minimal outgassing, with a total mass loss of 0.02%, collected volatile condensable material of 0.00%, and water vapor regain of 0.01% at 125°C and ≤ 10^-6 torr and there was no visible condensate.

 

Property

DiClad 870

Condition

Test Method

Electrical Properties

Dielectric Constant @ 10 GHz

2.33

C23/50

IPC TM-650 2.5.5.5

Dielectric Constant @ 1 MHz

2.33

C23/50

IPC TM-650 2.5.5.3

Dissipation Factor @ 10 GHz

0.0013

C23/50

IPC TM-650 2.5.5.5

Dissipation Factor @ 1 MHz

0.0009

C23/50

IPC TM-650 2.5.5.3

Thermal Coefficient of Er (ppm/°C)

-161

-10°C to +140°C

IPC TM-650 2.5.5.5
Adapted

Volume Resistivity (MΩ-cm)

1.5 x 10 9

C96/35/90

IPC TM-650 2.5.17.1

Surface Resistivity (MΩ)

3.4 x 10 7

C96/35/90

IPC TM-650 2.5.17.1

Arc Resistance

>180

D48/50

ASTM D-495

Dielectric Breakdown (kV)

>45

D48/50

ASTM D-149

Mechanical Properties

Peel Strength (lbs.per inch)

14

After Thermal Stress

IPC TM-650 2.4.8

Tensile Modulus (kpsi)

485(MD), 346(CD)

A, 23°C

ASTM D-638

Tensile Strength (kpsi)

14.9(MD), 11.2 (CD)

A, 23°C

ASTM D-882

Compressive Modulus (kpsi)

327

A, 23°C

ASTM D-695

Flexural Modulus (kpsi)

437

A, 23°C

ASTM D-790

Thermal Properties

Coefficient of Thermal Expansion (ppm/°C) X Axis Y Axis Z Axis

17 29 ?217

0°C to 100°C

IPC TM-650 2.4.24 Mettler 3000 Thermomechanical Analyzer

Thermal Conductivity (W/mK)

0.257

100°C

ASTM E-1225

Flammability UL

Meets requirements of UL94-V0

C48/23/50, E24/125

UL 94 Vertical Burn IPC TM-650 2.3.10

Physical Properties

Density (g/cm3)

2.26

A, 23°C

ASTM D-792 Method A

Water Absorption (%)

0.02

E1/105 + D24/23

MIL-S-13949H 3.7.7
IPC TM-650 2.6.2.2

Outgassing Total Mass Loss (%) Collected Volatile Condensable Material (%)Water Vapor Regain (%) Visible Condensate (±)

0.02 0.00 0.01 NO

125°C, ≤ 10-6 torr

NASA SP-R-0022A Maximum 1.00% Maximum 0.10%

 

A Piece of DiClad 870 Laminate

The screen displays a DiClad 870 microwave laminate.

 

DiClad 870 laminate is also commonly used in applications such as radar feed networks, commercial phased array networks, low loss base station antennas, and RF components like filters and couplers.

 

 

Conclusion

Rogers DiClad 870 materials are compatible with conventional electroless copper and direct deposit metallization processes, allowing for the use of standard equipment and chemical processes in the plating, imaging, and etching of circuit patterns on the material.

 

That's all for today's episode. Thank you for reading and we'll see you next time.