SF305 PI Film FCCL: Halogen-free, Flame-resistant Flexible PCB Material for Foldable Phones & Automotive Electronics

What is SF305?

SF305 is a flexible copper-clad laminate (FCCL) developed by Shengyi Technology. It’s a specialized material used to create flexible printed circuit boards (FPCs)—the kind of circuits that can bend, fold, and twist without losing functionality. Think of it as the backbone for electronics that need to be lightweight, durable, and adaptable, like foldable smartphones, wearable fitness trackers, or even advanced automotive systems.

What Makes SF305 Stand Out?

SF305 isn’t just another flexible material—it’s designed to solve specific challenges in modern electronics. Here’s a closer look at what makes it unique:

1. High-Frequency Performance

• Low Dielectric Loss (Df): At 10GHz, SF305 has a dissipation factor of just 0.0019, meaning it minimizes signal loss even at high frequencies. This is crucial for applications like 5G devices, where signal integrity is paramount.
• Stable Dielectric Constant (Dk): With a Dk of 3.3 at 10GHz, SF305 ensures consistent performance across a wide range of frequencies, making it ideal for high-speed data transmission.

2. Exceptional Flexibility

• SF305 is built to handle dynamic bending, which means it can withstand repeated folding and flexing without cracking or losing performance. This makes it perfect for devices like foldable phones or wearable gadgets that are constantly on the move.
• Its peel strength (≥1N/mm) ensures that the copper layers stay firmly bonded to the flexible substrate, even under stress.

3. Built to Last

• Thermal and Environmental Resistance: SF305 has been rigorously tested to perform in harsh conditions. It can handle high temperatures (up to 125°C), high humidity (85°C/85% RH), and even rapid thermal shocks (-40°C to 125°C). This makes it a reliable choice for automotive and industrial applications.
• Chemical Resistance: With a chemical resistance of ≥80%, SF305 can withstand exposure to harsh substances, ensuring durability in challenging environments.

4. Safety and Environmental Compliance

• SF305 is halogen-free and meets UL94 V-0 flammability standards, meaning it’s both environmentally friendly and safe to use in high-risk applications.
• It complies with RoHS standards, making it a green choice for manufacturers focused on sustainability.

5. Cost-Effective and Easy to Use

• Unlike some high-performance materials that require specialized equipment, SF305 is compatible with traditional FR-4 processing technology. This reduces production costs and simplifies manufacturing.
• It offers a higher cost-performance ratio compared to similar imported products (like DuPont Pyralux AP), making it an attractive option for budget-conscious projects.

Technical Specifications in Plain Terms

Here’s a breakdown of what SF305 looks like in a typical 2-layer flexible PCB design:

Layer Structure:

1. Top Copper Layer: 35 μm thick (about the thickness of a human hair).
2. Adhesive Layer: 20 μm thick, bonding the copper to the core.
3. Core Material: SF305 Polyimide Film, 25 μm thick—this is the flexible “backbone” of the PCB.
4. Bottom Copper Layer: 35 μm thick.
5. Board Dimensions: 75 mm x 62 mm (±0.15 mm)—compact and lightweight.
6. Trace/Space: 14/16 mils (minimum)—this determines how fine the circuit patterns can be.
7. Hole Size: 0.5 mm (minimum)—for mounting components or creating connections.
8. Finished Thickness: 0.24 mm—thin enough to be flexible but sturdy enough to handle wear and tear.
9. Surface Finish: Electroless Nickel Immersion Gold (ENIG)—ensures good conductivity and protects against corrosion.
10. Solder Mask: Yellow on both sides—this protects the circuit and gives it a clean, professional look.

Where Can You Use SF305?

SF305 is incredibly versatile and can be used in a wide range of industries. Here are some examples:

1. Consumer Electronics

• Foldable Smartphones: SF305’s flexibility and durability make it ideal for foldable screens and compact internal circuits.
• Wearable Devices: Smartwatches, fitness trackers, and AR/VR headsets benefit from its lightweight and bendable design.
• Digital Cameras and VCRs: Its high-frequency performance ensures smooth data transmission for high-resolution imaging.

2. Automotive Electronics

• Advanced Driver-Assistance Systems (ADAS): SF305’s reliability in harsh environments makes it perfect for radar systems and sensors.
• In-Car Entertainment: Flexible circuits for touchscreens and infotainment systems.

3. Medical Devices

• Wearable Health Monitors: SF305’s flexibility and durability make it ideal for devices that need to conform to the body.
• Diagnostic Equipment: Its high-frequency performance ensures accurate data transmission in medical imaging and monitoring systems.

4. Industrial and Office Automation

• Printers and Scanners: SF305’s flexibility allows for compact, efficient designs in office equipment.
• Robotics and Automation: Its durability and chemical resistance make it suitable for industrial applications.

Why Should You Consider SF305?

SF305 isn’t just a material—it’s a solution. Whether you’re designing cutting-edge gadgets, robust automotive systems, or life-saving medical devices, SF305 offers the performance, flexibility, and reliability you need. It’s cost-effective, environmentally friendly, and backed by rigorous testing, making it a smart choice for engineers and designers who want to push the boundaries of what’s possible.

In a Nutshell

SF305 is a high-performance, flexible PCB material that combines low signal loss, exceptional durability, and cost-efficiency. It’s designed for applications that demand both flexibility and reliability, from foldable phones to automotive radar systems. If you’re looking for a material that can keep up with your innovative designs, SF305 is worth a closer look.