Flexible PCBs (Printed Circuit Boards) use kinds of materials for their substrates, conductive layers, adhesive, and coverlay. Here are the common materials used, along with some brands and product number:
1. Flexible PCB Substrate Materials(PI, PET)
- Polyimide (PI): The most common substrate material for flexible PCBs due to its excellent heat resistance and mechanical strength.
- Brands & Models:
- DuPont: Kapton® (e.g., Kapton® HN, Kapton® FN)
- Fujifilm: Fujiflex™ PI
- Isola: IS5200 PI
- Brands & Models:
- Polyester (PET): A more affordable option, commonly used for lower to mid-tier applications, but with lower heat resistance compared to PI.
- Brands & Models:
- Toray: Trevira® PET
- Teijin: Teijin PET
- Brands & Models:
- Polyvinyl Chloride (PVC): Typically used in lower-end flexible PCBs where high temperature resistance is not critical.
2. Flexible PCB Conductive Materials
- Copper Foil: Commonly used for conductive layers, providing the electrical circuit for flexible PCBs.
- Brands & Models:
- Mitsui Mining & Smelting: Mitsui Copper Foil
- JX Nippon Mining & Metals: Nippon Copper Foil
- Sumitomo Electric: Sumitomo Copper Foil
- Brands & Models:
- Silver (Ag) and Gold (Au): Used in high-frequency or high-performance applications for their superior electrical properties and low contact resistance.
- Brands & Models:
- Herotek: Ag for high-frequency applications
- AT&S: Gold-plated copper foil for fine-pitch and high-frequency
- Brands & Models:
3. Flexible PCB Adhesive Materials
- Epoxy Resin: Commonly used for bonding copper foil to the substrate, offering high strength and good electrical performance.
- Brands & Models:
- Huntsman: Araldite® (e.g., Araldite® 2020, Araldite® 2030)
- 3M: 3M™ Scotch-Weld™ Epoxy Adhesive DP190
- Brands & Models:
- Polyurethane (PU): Offers flexibility and is used in some high-temperature environments.
- Brands & Models:
- Henkel: Loctite® 4090
- Brands & Models:
- Acrylics: Used for applications requiring transparency or specific environmental resistance.
- Brands & Models:
- Dymax: Dymax 1000
- Brands & Models:
4. Flexible PCB Coverlay
- Polyurethane Film: Commonly used as a protective layer to enhance wear resistance, oxidation resistance, and insulation.
- Brands & Models:
- DuPont: Kapton® (for high-temperature applications)
- 3M: 3M™ Polyester Film
- Brands & Models:
The choice of materials depends on the required PCB performance, environmental conditions, and cost considerations. For example, Kapton® PI substrates are commonly used in high-temperature, harsh environments, while PET substrates are more cost-effective for low-end applications.
Don’t hesitate to contact us if you have any questions about the flexible circuit. The following shows the performance parameter and datasheets of some material for flex PCB. Click the material name you can see the pdf datasheet.
| Material for flexible PCBs | Recommended max. operating temperature | Copper type | Tg | Ԑr, Dk- Permittivity | CTE-z (T<Tg) | Electric Strength | Surface resistivity | Peel strength |
|---|---|---|---|---|---|---|---|---|
| °C | * | °C | @1MHz | ppm/°C | KV/mm | MΩ | N/mm | |
| Polyimide + Adhesive | ||||||||
| Shengyi SF305 | 105° | Rolled Copper | – | 3,6 | 21 | – | 1 x 10^5 | 1,1 |
| Polyimide | ||||||||
| DuPont Pyralux AP | 180° | Rolled Copper | 220 | 3,4 | 25 | 256 | 1 x 10^10 | 1.8 |
| Panasonic RF775 | 130° | Electrolytically Deposited Coppe | 343 | 3,2 | – | 276 | 1 x 10^8 | 1,7 |
| Thinflex W-05050 | 105° | Electrolytically Deposited Coppe | 350 | 3,3 | 24 | 216 | 1 x 10^5 | 0.6 |
| PI Coverlay | ||||||||
| Shengyi SF305 | 105° | – | – | – | – | – | 3 x 10^6 | – |
| DuPont Pyralux FR | 180° | – | – | 3.5 | – | 138 | 1 x 10^7 | – |
| Adhesive tape | ||||||||
| 3M 9077 | 150° | – | – | – | – | – | – | – |
