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Next Generation Resin for 5G

SF Resin

Applicable Business Areas

Next Generation Vehicles, High-speed Antenna

Target Applications

Aerospace, Automotive, 5G Communication, Millimeter Wave Communication, Base Stations

Stress free (SF) Resin is a newly developed material by Hitachi Chemical. It can maintain its low dielectric characteristics, flexibility, and adhesion from very high to very low temperatures, facilitating next generation “5G” millimeter wave communication technology.

Obstacles in the race to 5G

Next generation communication systems, “5G”, are expected to enable high-speed, large-capacity, data communication. In addition, millimeter wave communication is expected to allow for the safe operation of self-driving automobiles. To realize this potential, it is necessary to utilize higher frequency bandwidths.

Currently, studies are being conducted with high-speed antennas that can be used in next generation mobility and base stations. These studies are focused on resin materials with low dielectric properties which can suppress transmission loss that occurs in high frequency bandwidths.

Existing low dielectric epoxy resins and polyimide resins do not have sufficient flexibility in a wide temperature range from -40°C to 150°C. They are brittle under freezing conditions and can be broken easily.

SF Resin does not have this problem.

Innovative Solutions

Maintains Flexibility in Extreme Temperatures

Flexible devices used for next generation mobility require elasticity and durability across temperatures ranging from -40°C to 150°C.

Films made with existing epoxy or polyimide resins are easily broken when dipped in liquid nitrogen and then bent. But a film made with SF resin can be dipped in liquid nitrogen and then bent, without breaking or creasing.

SF Resin

Low Dielectric Properties Reduce Transmission Loss

Like losing water flowing through a leaky pipe, 5G communications require the best signal insulation to prevent loss and achieve their potential. SF Resin combines excellent physical properties with singular dielectric properties that enable high speed transmission of information with low loss.

The lower the Df value, the lower the transmission loss caused by the material. With a Df value of 0.002 (@10 GHz), SF Resin reduces transmission loss by 30% from the current industry standard within the millimeter wave range (76-79 GHz). This allows for higher wave intensity, resulting in stronger signals from the antenna and enabling advanced self-driving technology.

High Adhesion to Many Types of Materials

Hitachi Chemical’s SF Resin has strong adhesion to metals, glass, and polymers without using primer or special surface treatment.

Fig.1 Peel strength of copper foil and polyimide film
Fig.2 Shear strength to metal substrate

Minimal Cure Shrinkage Reduces Final Product Warpage

SF Resin is a flexible resin material with low modulus. When coated on a wafer and cured, observed shrinkage is smaller when compared with polyimide resins, and substrate warpage can be reduced.

SF Resin, PI Resin

Flexibility for Increased Mobility

The world is moving towards an era of flexible mobile electronics. Customers need a resin material which can protect their electronics without limiting their mobility. SF Resin is capable of 150% elongation, and has an elastic modulus under 0.5 GPa, showing excellent durability during bending.

Comparison with Other Resin Materials

Item

Property

Unit

SF Resin

Epoxy

PI

Silicone

Heat Resistance

Weight loss (300ºC)

%

<0.5

>5

1-2

0.5-1

Decomposition temp (5%)

ºC

400

300

350

350

Dielectric Properties

Dk @10 GHz

-

2.4

4.0

3.5

4.0

Df @10 GHz

-

0.002

0.01

0.006

0.0098

Adhesion

Cu Peel Strength

kN/m

1.6-2.0

1.9

1.6

<0.1

Low Shrinkage

Cure Shrinkage

%

<0.1

1.0

0.8

<0.1

Flexibility

E’

GPa

<0.5

2.4

4.5

0.01

Tg

ºC

43

150

260

<-50

Elongation

%

150

10

10

200