When designers talk about Isola FR408HR, they’re referring to Isola’s specialized high-performance FR‑4 laminate, widely specified for high-frequency PCBs and high Tg PCB designs. To learn more about the foundational material category that FR408HR belongs to, check out our guide: What Is CCL? Copper Clad Laminate for PCB Manufacturing.
In real PCB production, specialized high-frequency materials carry higher costs and lower overall demand. That’s why relatively few manufacturers keep these materials in regular stock.
Isola FR408HR is a proprietary resin system built for multilayer printed wiring boards, with a glass transition temperature of 230°C measured by DMA (190°C by DSC)—a key distinction from standard FR-4 materials which typically have lower Tg values. It’s chosen where consistent thermal performance and long‑term reliability are non‑negotiable.
This laminate also supports laser fluorescence and UV blocking, which helps with compatibility across AOI systems, optical positioning tools, and photo‑imagable solder mask processes.
Key Performance Attributes
This material stands out for its thermal stability, making it suitable for high‑speed digital circuits and high‑density interconnect designs—critical for applications where signal integrity and heat management go hand in hand.
Unlike standard FR‑4, it holds performance under extreme thermal stress, which is why it’s preferred in designs that see repeated assembly and field exposure.
Recognitions & Material Specs
FR408HR carries industry validation that matters for production and compliance:
- UL File Number: E41625
- Fully RoHS compliant
On the performance side, it offers strong resistance to CAF, works with lead‑free assembly, and supports 0.8 mm pitch designs.
It also withstands six cycles at 260°C reflow (with a total time above 260°C of 60 minutes) and six cycles of 288°C solder float (with each cycle lasting over 30 seconds) without degradation, aligning with standard lead-free assembly requirements.
Practical Processing Advantages
Beyond raw performance, Isola FR408HR brings real benefits to manufacturing workflows.
Its UV‑blocking and AOI fluorescent properties simplify inspection and alignment steps—an often-overlooked benefit that speeds up production workflows. The material also supports via filling and can handle multiple lamination cycles, which adds flexibility for complex multilayer boards, unlike some standard FR-4 laminates that struggle with repeated processing.
Typical End-Use Applications
You’ll find FR408HR in sectors where reliability and signal integrity can’t be compromised:
- Aerospace and defense systems
- Computing, data storage and peripherals
- Networking and communications equipment
- Medical devices
- Industrial and instrumentation electronics
If you’re planning a PCB build using FR408HR PCB material, OPCBA can support your production needs.
Reach out to our team to obtain the full official datasheet and specifications for Isola FR408HR.
