Introduction:

The development and widespread use of flexible PCBs can be attributed to their significant advantages. First, their adaptable structure, compact size, light weight, and high quality meet the requirements of modern electronic products. Additionally, flexible PCBs can be extended into three-dimensional spaces, enhancing both circuit and mechanical design freedom. These advantages reduce the overall workload and assembly errors while significantly improving the reliability and stability of the electronic equipment system.

Pretreatment:

During production, pretreatment is essential to minimize defects like open or short circuits and reduce issues like drilling, rolling, or cutting errors. Proper material selection is crucial for meeting customer requirements and producing the most effective flexible PCBs. This highlights the importance of effective pretreatment to ensure high yield and quality in the manufacturing process.

Manufacturing Process:

Double-Sided Flex-PCB:

Cutting → Drilling → PTH → Electroless Plating → Pretreatment → Dry Film Lamination → Positioning → Exposure → Developing → Pattern Plating → Remove Dry Film → Pretreatment → Dry Film Lamination → Positioning and Exposure → Developing → Etching → Remove Dry Film → Surface Finish → Coverlay Lamination → Lamination → Curing → Immersion Gold → Silkscreen → V-Cutting/Scoring → Electrical Testing → Punching → FQC → Packaging → Shipment

Single-Sided Flex-PCB:

Cutting → Drilling → Dry Film Lamination → Positioning and Exposure → Developing → Etching → Remove Dry Film → Surface Finish → Coverlay Lamination → Lamination → Curing → Surface Finish → Immersion Gold → Silkscreen → V-Cutting/Scoring → Electrical Testing → Punching → FQC → Packaging → Shipment

Size and Weight Reduction Benefits of Flexible Circuitry:

Flexible circuitry is the preferred solution for manufacturers requiring:

• Wiring solutions for spaces where rigid boards are unsuitable.
• Thin, lightweight products that remain durable.
• Miniaturized versions of existing technologies.
• Three-dimensional packaging designs.
• A minimal number of device interconnects.
• Resistance to shock and vibration.

These advantages make flexible circuitry ideal for mobile consumer electronics. Enthusiasts who dismantle smartphones or laptops will often find flexible PCBs inside modern devices.

For mobile devices, rigid circuitry would make the device excessively bulky, heavy, and fragile. An example of this was the Osborne I, the first fully powered mobile computer, which weighed 24.5 pounds. While size and weight reduction are crucial benefits, flexible circuits are also highly effective in high-temperature and high-density applications.

High-Temperature and High-Density Applications:

Flexible circuits are often made from polyimide or similar polymers, which dissipate heat more efficiently than most rigid circuit board materials. This makes flexible PCBs suitable for locations where heat could degrade rigid boards’ performance.

These circuits can withstand extreme temperatures ranging from -200°C to 400°C, making them ideal for applications such as borehole measurements in the oil and gas industry.

Due to these properties, and the need for compact devices in industrial settings, flexible circuits are the preferred choice in many sensor technologies.

High-temperature resistance often comes with excellent chemical resistance and protection against radiation and UV exposure. When combined with the ability to control impedance in high-density designs, flexible circuits offer substantial benefits to manufacturers.

Why Not Make All Circuit Boards Flexible?

Flexible circuit boards are certainly useful, but they are not going to replace rigid circuit boards for all applications. Cost efficiency is the main obstacle to implementing an exclusively flexible circuit board design in a consumer product. Rigid circuit boards are less expensive to manufacture and install in a typical automated high-volume fabricating facility.

Typically, the ideal solution for an innovative product is one that incorporates flexible circuitry when necessary, and employs solid, reliable rigid circuit boards where possible to keep manufacturing and assembly costs down.

Some manufacturers even use hybrid rigid-flex printed circuit boards expressly for this purpose. This is common in laptop computers and medical devices, where rigid circuit boards can be connected to one another using ribbon-like flexible circuits. These boards can be compounded and designed to meet various engineering needs by leveraging the respective strengths of each circuit board technology.

Wellcircuits


creates both flexible and printed circuit boards for product manufacturers. Enjoy a consultation with one of our sales representatives to determine whether your product prototype design is better served by flexible or rigid circuit board types.

If you have any questions about PCB and PCBA, please contact me at
info@wellcircuits.com.