Flexible PCB + Metal Dom – SY03

Flexible Printed Circuit (FPC) Design Advantages

The ability to bend, fold, and configure a flexible circuit board into virtually any shape or thickness offers designers immense flexibility when creating electronic packages. Unlike traditional hardboard circuits, flexible circuits allow for much more compact and efficient use of space. This flexibility enables several key advantages:
Design Versatility

• FPCs can be designed to fit into tight or irregular spaces, making them ideal for compact electronic devices. This versatility helps in creating electronic packages that are smaller, lighter, and more functional.

Reduced Size and Weight

• The inherent flexibility of FPCs allows for significant reductions in the size and weight of electronic assemblies, which is crucial for modern, portable electronic devices.

Lower Assembly and Handling Costs

• With FPCs, the entire interconnect system can be built as a single integrated part, simplifying the assembly process. This integration reduces the need for multiple connectors and cables, thereby decreasing handling and assembly costs.

Enhanced Reliability

• FPCs are less prone to connection failures because they reduce the number of solder joints and connectors. The single-piece construction eliminates many potential points of failure, enhancing the overall reliability of the electronic assembly.

Improved Signal Integrity

• Flexible circuits often provide better signal integrity due to shorter interconnects and the ability to maintain consistent impedance. This can be critical in high-speed or sensitive electronic applications.

Simplified Supply Chain Management

• Shanyo’s capabilities in component assembly and testing further streamline the supply chain. With Shanyo handling these aspects, customers benefit from reduced complexity in managing multiple suppliers and logistics.

Increased Functionality

• The design flexibility of FPCs allows for more complex circuit layouts, which can support increased functionality in a given space. This leads to more advanced and feature-rich electronic products.

the use of flexible printed circuits can significantly enhance the design and manufacturing of electronic devices, making them more compact, reliable, and cost-effective. Shanyo’s expertise in this area ensures high-quality, customized solutions that meet the specific needs of various industries.

Flexible Printed Circuit Fabrication

Subtractive Processes

In subtractive processes, a solid layer of metal, typically copper, is applied to a dielectric substrate. The unwanted metal is then removed to create the desired circuit patterns. This is usually done through:

1. Screen Printing: A stencil or screen is used to apply an etch-resistant material in the desired pattern on the copper layer. The board is then exposed to an etchant that removes the unprotected copper, leaving behind the circuit pattern.

2. Photo Imaging: A photoresist material is applied to the copper layer, which is then exposed to UV light through a photomask. The exposed areas harden, and the unexposed areas are washed away. The board is then etched to remove the unprotected copper.

Advantages:
– Robustness: Subtractive processes are well-established and reliable.
– Cost-Effective: Economical for high-volume production.
– Flexibility: Allows for various configurations and complex designs.

Additive Processes

In additive processes, the circuit pattern is built up by adding conductive material only where it is needed. The dielectric substrate is initially bare, and conductive traces are added through:

1. Printing: Conductive inks or pastes are printed onto the substrate in the desired pattern.
2. Plating: Conductive materials are electroplated onto the substrate through a patterned mask.
3. Deposition: Methods like sputtering or vapor deposition are used to apply the conductive material.

Advantages:
– Material Efficiency: Less waste as only the required conductive material is deposited.
– Environmental Benefits: Reduced use of chemicals and etchants.

Disadvantages:
– Lower Current-Carrying Capability: Conductive layers are typically thinner than those produced by subtractive processes.
– Reduced Environmental Resistance: May not perform as well in harsh conditions.

Comparison

Subtractive Processes:
– Common: Widely used due to established methods and equipment.
– Versatile: Suitable for complex and high-density designs.
– Cost-Effective: Lower production costs, especially for large volumes.
– Robust: High reliability and durability.

Additive Processes:
– Emerging: Used in specific applications where material efficiency and environmental considerations are crucial.
– Limited: Generally not suitable for high-power or high-current applications.
– Specialized: Used for applications requiring minimal material usage and fine-line patterns.

While subtractive processes remain the industry standard due to their robustness, cost-effectiveness, and versatility, additive processes offer significant advantages in terms of material efficiency and environmental impact, making them suitable for specialized applications.

Flexible Printed Circuit Finishing and Assembly

Flexible Printed Circuit (FPC) finishing and assembly are crucial steps to ensure the functionality and reliability of the circuit. Here’s a detailed overview:

Surface Finishing
To prepare the FPC surface for bonding processes like SMT (Surface Mount Technology) assembly, wire bonding, or pressure connector insertion, surface finishing is essential. Common finishing materials include:

– Nickel or Gold: Often used for their excellent conductivity and resistance to oxidation.
– Tin: Provides good solderability.
– Silver: Offers excellent electrical conductivity.
– Solder: Ensures reliable electrical connections.
– Organic Coatings: Protect the copper until the bonding process, where the coating dissolves away.

Assembly Options
FPCs offer numerous assembly possibilities:

– Electronic Components and Connectors: FPCs can accommodate various components and connectors, making them versatile for different applications.
– Electrical or Mechanical Devices: These can be attached to FPCs to enhance functionality.
– Bonding to Curved Surfaces: FPCs can be easily bonded to curved or irregular surfaces.
– 3D Shapes: FPCs can be formed into any three-dimensional shape, increasing design flexibility.
– Dynamic Flexing: Properly constructed FPCs can handle dynamic flexing, ideal for applications involving moving or rotating parts.

Design Potential
The potential of FPCs is vast, limited only by the designer’s imagination. Their flexibility, durability, and versatility make them suitable for a wide range of applications in various industries, including electronics, automotive, medical devices, and more.

Contact an Expert
For detailed guidance and to explore the possibilities of FPCs, consulting with a design engineer can provide valuable insights and innovative solutions tailored to specific needs.

China Flexible Printed Circuit Board Basic Structure

Copper Film

The copper film is divided into electrolytic copper and rolled copper. The common thicknesses are 1oz 1/2oz and 1/3 oz.
Substrate Film: Common thicknesses are 1 mil and 1/2 mil.
Glues: Thickness depends on the customer’s requirement.

Cover Film

Cover Film: For surface insulation. Common thicknesses are 1mil and 1/2mil.
Glues: Thickness depends on the customer’s requirement.
Release Paper: To avoid foreign matter from adhesive before pressing; to facilitate the work.

PI Stiffener Film

PI Stiffener Film: Reinforces the mechanical strength of the FPC and facilitates the surface mounting process. Common thicknesses range from 3mil to 9mil.
Glues: Thickness depends on the customer’s requirement.
Glues (Adhesives): To avoid adhesive from sticking to foreign objects before pressing.
EMI: Electromagnetic shielding film protects the circuit board circuit from outside (a strong electromagnetic area or susceptible to interference area) interference.

Bottom line, if you have flex circuit design or flex printed circuit board needs, we can help. contact us