The Power of 370HR Exploring High-Reliability PCBs for Critical Applications
1.Introduction to 370HR
Isola's 370HR is a high-performance 180°C glass transition temperature (Tg) FR-4 system for multilayer Printed Circuit Board (PCB) applications. It's manufactured with a unique high-performance multifunctional epoxy resin, reinforced with electrical grade (E-glass) glass fabric. The system is also laser fluorescing and UV blocking for maximum compatibility with Automated Optical Inspection (AOI) systems, optical positioning systems, and photoimageable solder mask imaging. 370HR has proven to be best in class for sequential lamination designs.
2.Key Features of 370HR PCBs
High Thermal Performance
Tg: 180°C (DSC)
Td: 340°C (TGA @ 5% wt loss)
Low X/Y-Axis CTE of 13/14ppm/°C for reliability
T260: 60 minutes
T288: 30 minutes
RoHS Compliant
UV Blocking and AOI Fluorescence
High throughput and accuracy during PCB fabrication and assembly
CAF Resistant
Superior Processing: Closest to conventional FR-4 processing
3.PCB Construction Details:
| Specification | Details |
|---|---|
| Base Material | 370HR |
| Layer Count | 6-layer |
| Board Dimensions | 102.87mm x 128.5 mm (4up), +/- 0.15mm |
| Minimum Trace/Space | 4/4 mils |
| Minimum Hole Size | 8 mils |
| Vias | 198 |
| Blind/Buried Vias, Slot Holes | No Blind or Buried Vias, No Slotted Holes |
| Finished Copper Weight | 1 oz signal and plane layers |
| Top/Bottom Silkscreen | White |
| Top/Bottom Solder Mask | Green |
| Board Thickness | 40.4 mils / 1.02mm +/- 0.05mm |
| Edge Routing | All Edges Tab-Routed, Non-Plated Holes for Breakouts |
| UL Mark | UL Mark on PCB Required |
| Electrical Test | Electrical Test Required |
| Silkscreen on Pads | Ensure No Silkscreen on Solder Pads |
| Panel Breakouts | Panel Breakouts Required |
| Surface Finish | ENIG, with 0.1um (0.004 mils) gold, for -40°C to +85°C |
4.Impedance Matching
Layer 1: 10mil single end, 50 ohm, reference layer 2
Layer 3: 6mil single end, 50 ohm, reference layer 2
Layer 4: 6mil single end, 50 ohm, reference layer 5
Layer 6: 10mil single end, 50 ohm, reference layer 5
Impedance matching tolerance: +/- 10%
5.PCB Stackup (6-Layer Rigid PCB)
Top Silk Layer
Top Mask Layer
Top Layer (PCB Layer 1) - 1.4mil (1oz)
IS370 HR - 6mil
Ground Plane (PCB Layer 2) - 1.4mil (1oz)
IS370 HR - 6mil
Mid Layer 1 (PCB Layer 3) - 1.4mil (1oz)
IS370 HR - 8mil
Mid Layer 2 (PCB Layer 4) - 1.4mil (1oz)
IS370HR - 6mil
Power Plane (PCB Layer 5) - 1.4mil (1oz)
IS370HR - 6mil
Bot Layer (PCB Layer 6) - 1.4mil (1oz)
Bot Mask Layer
Bot Silk Layer
6.PCB Statistics
Components: 120
Total Pads: 267
Thru Hole Pads: 37
Top SMT Pads: 218
Bottom SMT Pads: 12
Nets: 58
7.Accepted Standards
Artwork Format: Gerber RS-274-X
Quality Standard: IPC-Class-2 compliant
Availability: Worldwide production and shipping
8.Target Applications
Computing, Storage & Peripherals
Networking & Communications
Automotive & Transportation
Consumer Electronics
Aerospace & Defense
Medical, Industrial & Instrumentation