Flexible Printed Circuit Boards (PCBs) have revolutionized the
electronics industry, providing essential solutions for compact and
lightweight designs. Let's delves into the construction,
specifications, and applications of a double-sided flexible PCB
made from polyimide, highlighting its advantages and potential
uses.
| Specification | Details |
| Base Material | Flexible polyimide |
| Layer Count | Double sided |
| Board Dimensions | 51mm x 35mm (+/- 0.15mm) |
| Minimum Trace/Space | 5/5 mils |
| Minimum Hole Size | 0.4mm |
| Blind Vias | No |
| Flex Thickness | 0.22mm |
| Flex + PI Stiffener Thickness | 0.3mm |
| Flex + FR4 Stiffener Thickness | 1.34mm |
| Finished Cu Weight | 2oz (2.8 mils outer layers) |
| Via Plating Thickness | 20 μm |
| Surface Finish | Electroless Nickel Immersion Gold (ENIG) |
| Top Silkscreen | White |
| Bottom Silkscreen | No |
| Top Solder Mask | Yellow coverlay |
| Bottom Solder Mask | No |
| Electrical Testing | 100% Electrical test prior to shipment |
Thickness and Layer Configuration
The flex thickness is 0.22mm, with different thicknesses depending
on the stiffener used:
- Flex + PI Stiffener: 0.3mm
- Flex + FR4 Stiffener: 1.34mm
PCB Stackup
The stackup of this 2-layer flexible PCB consists of:
- Copper Layer 1: 70 μm
- Adhesive Polyimide Core: 25 μm (1 mil)
- Copper Layer 2: 70 μm
This configuration combines flexibility with structural integrity,
making it suitable for various applications.
Features of Adhesive Polyimide
The adhesive polyimide used in this PCB boasts several advantageous
properties:
- Halogen-free and compliant with the EU RoHS directive, free of
hazardous materials like Pb, Hg, Cd, Cr6+, PBB, and PBDE.
- Flammability rated at UL94 V-0.
- Exceptional flexibility and thermal resistance.
- Dimensional stability with a moisture absorption rate of
1.37-1.46%.
- A dielectric constant ranging from 3.31 to 3.34 at 10 GHz,
crucial for high-frequency applications.
- Chemical resistance of 85% and a dissipation factor of
0.0188-0.0191 at 10 GHz.
Testing and Quality Standards
To ensure reliability, a 100% electrical test is performed before
shipment, adhering to IPC-Class-2 quality standards. This rigorous
testing process guarantees that every unit meets the necessary
performance criteria.
Typical Applications
Flexible PCBs are widely utilized in various industries, including:
- Computers
- Mobile Phones
- Digital Cameras
- VCRs
- Automobiles
- Office Automation Equipment
These applications benefit from the lightweight and customizable
nature of flexible PCBs, facilitating advanced designs that cater
to modern electronic demands.
Conclusion
This flexible PCB, constructed from high-quality polyimide
materials, exemplifies the advancements in PCB technology. Its
specifications, robust construction, and versatile applications
make it an indispensable component in today’s electronic devices,
reflecting the industry's shift towards more flexible and efficient
designs. With global availability, this PCB is poised to meet the
needs of innovators across various sectors.
