Thanks to the advantages (e.g. cost, space and weight savings) that flexible and Rigid-Flex PCBs offer, they are being used more and more frequently. The areas of application for flexible printed circuit boards (also known as FPC, Flexible Printed Circuit) are constantly expanding. They are used in important electronics sectors such as the automotive industry, consumer electronics, medical technology, telecommunications, wearables clothing and aerospace.
At Multi-CB, you can obtain flexible printed circuit boards both as prototypes and as series in the highest quality with 1-10 layers (also plated-through). Assembly options with or without adhesive (adhesiveless), polyimide or FR4 stiffeners, also with airgap design.
The standard surface used is chemical gold (ENIG), the contours are formed according to requirements, preferably using laser cutting, or also with mechanical milling.
You should discuss the selected materials and design for the construction and layout of flexible circuit boards with us in the planning phase; we can assist you to work out the optimum solution!
Please contact our CAM-Station-Team (tel. +49-8104-6280) for additional technical questions about flexible circuit boards. Please mind also our Design-Aid for flexible circuit boards.
Technical options for flexible circuit boards
| Options | Inclusive | Notes | |
|---|---|---|---|
| Execution | 1-10 layers plated through | - | Layer buildup |
| Track min. | 100µm | 100µm | |
| Restring min. | 100µm | 100µm | |
| Via min. Ø | 0.15mm | 0.2mm | |
| Surfaces | immersion gold (recommended), ENEPIG, chem. Silver | immersion gold | Interfaces |
| Materials | Polyimide, Polyimide High TG | Polyimide | Materials |
| Material thickness | from 25µm foil plus copper | 25µm, 50µm | |
| Copper thickness | from 18µm | 18µm, 35µm | |
| Stiffeners | 0.025mm - 3.2mm | 0.2mm, 0.3mm | |
| Max. Size | 250mm x 450mm | - | larger on request |
| Coverage | PI coverlay (e.g. multiple bending cycles) or flexible solder stop (e.g. stable bending) | PI coverlay 25µm | |
| Bar width min. | Coverlay: ≥ 350µm flexible solder stop: ≥ 100µm | - | Design-Aid |
| Impedance Control | yes (10% tolerance) | - | |
| Adhesive tape | 3M 9077 | - | Materials |
Material for flexible circuit boards
| 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° | RA | - | 3,6 | 21 | - | 1 x 10^5 | 1,1 |
| Polyimide | ||||||||
| DuPont Pyralux AP | 180° | RA | 220 | 3,4 | 25 | 256 | 1 x 10^10 | 1.8 |
| Panasonic RF775 | 130° | ED | 343 | 3,2 | - | 276 | 1 x 10^8 | 1,7 |
| Thinflex W-05050 | 105° | ED | 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° | - | - | - | - | - | - | - |
* RA = Rolled copper, suitable for dynamic, flexible applications; ED = Electrolytically deposited copper , only suited for stable and semi-dynamic applications (see Design-Aid Flex boards)
UL certification for flexible circuit boards
At Multi-CB, you also get one-sided and multilayer flexible printed circuit boards with UL certification.
Example - Stiffener
You can order your flexible circuit boards with a stiffener. The available thicknesses are: 0,075mm - 3,20mm.
Popular are the thicknesses 0,30mm and 0,20mm, e.g. for ZIF connectors.
Polyimid-Stiffener: 0,025mm - 0,225mm
FR4-Stiffener: 0,075mm - 3,20mm
In the Flex PCB calculator the final thickness (incl. stiffener) is given.