Advanced 6-Layer PCB Solutions Using 370HR Material for High Performance

(Custom PCBs are tailored products; the images and specifications provided are for reference only.)

Introduction to ISOLA 370HR:

370HR laminates and prepregs, designed by Polyclad, utilize a patented high-performance FR-4 multifunctional epoxy resin system with a glass transition temperature (Tg) of 180°C, making it suitable for multilayer PCB applications where maximum thermal performance and reliability are essential. Manufactured with high-quality E-glass fabric, 370HR offers superior conductive anodic filament (CAF) resistance, low coefficient of thermal expansion (CTE), and excellent mechanical, chemical, and moisture resistance properties.

370HR is widely adopted in PCB designs and is recognized for its thermal reliability, ease of processing, and proven performance in sequential lamination.

Properties:

Glass Transition Temperature (Tg): 180°C
Decomposition Temperature (Td): 340°C (5% weight loss)
Time to Delaminate: T260 of 60 minutes, T288 of 30 minutes
Coefficient of Thermal Expansion (CTE):
Pre-Tg: Z-Axis: 45 ppm/°C, X/Y-Axis: 13/14 ppm/°C
Thermal Conductivity: 0.4 W/MK
Dielectric Constant (DK):3.92 at 5 GHz, 4.24 at 100 MHz, 4.17 at 1 GHz, 4.04 at 2 GHz
Loss Tangent (Df):0.025 at 5 GHz and 10 GHz, 0.015 at 100 MHz, 0.0161 at 1 GHz, 0.021 at 2 GHz
Dielectric Breakdown: > 50 kV
Comparative Tracking Index (CTI): 175V-249V
Moisture Absorption: 0.15%
Flammability Rating: UL94-V0

PCB Construction Details:

Specification	Details
Base Material	370HR
Layer Count	6 layers
Board Dimensions	40mm x 55mm (± 0.15mm)
Minimum Trace/Space	4/4 mils
Minimum Hole Size	0.2mm
Blind Vias & Buried Vias	GTL to INN 1, INN2-INN3
Finished Board Thickness	1.6mm
Finished Copper Weight	1 oz (1.4 mils) for inner and outer layers
Via Plating Thickness	20 µm
Surface Finish	ENIG (Electroless Nickel Immersion Gold)
Top Silkscreen	White
Bottom Silkscreen	White
Top Solder Mask	Green
Bottom Solder Mask	Green
Top Layer Traces	10 mils with 50-ohm impedance control
Electrical Testing	100% Electrical Testing conducted prior to shipment

6-Layer PCB Stackup (370HR):

Layer	Filename	Thickness (mil)
Signal	Top	1.4
Plane	GND	1.4
Signal	SIG1	1.4
Signal	SIG2	1.4
Plane	PWR	1.4
Signal	Bottom	1.4
Total		62.0 mil

PCB Statistics:

Components: 31
Total Pads: 46
Through Hole Pads: 29
Top SMT Pads: 17
Bottom SMT Pads: 0
Vias: 24
Nets: 5

Artwork and Standards Information

Type of Artwork Supplied: Gerber RS-274-X
Accepted Standard: IPC-Class-2
Availability: Worldwide

Attributes:

• High thermal reliability
• High-density interconnects

Typical Applications:

• Computing, Storage & Peripherals
• Consumer Electronics
• Networking & Communications
• Medical, Industrial, and Instrumentation
• Automotive and Transportation
• Aerospace and Defense