Flex PCB Benefits

There are some pretty amazing benefits to using flexible PCBs. Some of the advantages of flexible PCBs include the following:

• Reduced Space and Weight: Most of the advantages associated with flexible PCBs come from their low volume and weight. In fact, using a flexible PCB instead of a rigid PCB can result in a space reduction of over 50 percent and a weight reduction of 95 percent, while simultaneously maintaining the function and reliability of the circuit.
• Durability: The flexibility, reduced weight and reduced number of interconnects in the PCB allows them to handle changing external forces and improve their resistance to shock and vibration.
• Signal Integrity: Flexible PCBs work in a wide range of environments, so signals will continue to perform smoothly despite exterior conditions. This improves the PCB’s signal reliability.

• Higher Density: The thin flex layers and smaller parts mean that flexible PCBs are capable of supporting higher circuit densities.
• Minimized Errors: Due to the elimination of mechanical connectors and reduced variations in assembly methods, flexible PCBs experience reduced wiring errors.
• Low Cost: Because of the fewer assembly steps involved in the creation of flexible PCBs, they tend to be relatively low-cost.
• Heat Dissipation: The thinner flex PCB materials allow for a greater surface-area-to-volume ratio, improving heat dissipation.

Materials for Flex Circuits

Flexible circuits come in single-sided, double-sided and multi-layered forms, each of which requires a variety of materials to function. The materials that MCL works with include branded materials from trusted suppliers. A few of the flex PCB materials you can choose from include these:

• Adhesives: The requirements of an application, as well as the dimensions of the conductor involved, tend to guide adhesive selection. Some of the most popular adhesives on the market include acrylics, epoxies, pressure-sensitive adhesives (PSAs) and adhesive-free base materials.
• Finishes: You can choose from a variety of final finishes to meet the requirements of your project. A few of the finishes you can choose from include ENIG, HASL, Pb-free HASL, immersion silver, and immersion tin, and even organic materials. Each option creates different results and is best suited to different applications, so be sure to consult with MCL on the best finish for your needs.
• Insulators: Insulators are a must, and you’ll need the right insulating material to support your flexible PCB application. The wrong insulator might result in PCB failure in the long term. PCB insulators combine coverlay materials and flexible substrates in a variety of form factors and thicknesses. Some of the most used insulators include flexible solder masks, photo imageable coverlays, polyester, polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyimides, screen-printed dielectric insulators and solder masks.

We recommend you contact us directly in order to determine the best material for your PCB needs. Below are a few more options for you to consider ahead of making that call.

Advanced Features

The flex circuit market has continued to expand. With that expansion, advances in the technology have grown as well, including the following:

• Graphic Overlays: Graphic overlays are acrylic or polyester covers for PCBs that provide a type of user interface with the circuit underneath. These overlays often include LEDs, LCDs and switches, which allow the user to interact with the PCB in the desired fashion.
• Hot Bar Solder: A hot bar solder connection is an alternative to a standard connection, eliminating the need for a connector between a hardboard and flex circuit. The result is a more efficient and durable connection that is less expensive.
• Laser Skived Slots and Holes: In the past, razors were used to cut flex circuits, and the success of this process was dependent upon the person cutting the lines. With modern lasers, however, lines can be cut with extreme precision and control, resulting in even finer circuit designs in flexible PCBs.
• Panelization: This process involves assembling PCBs in large panels of multiple units. It can expedite the flex circuit assembly process substantially, especially in “pick-and-place” assembly lines. Once the units are assembled, all you need to do is break the groups apart.
• Pressure-Sensitive Adhesives: Called PSAs for short, pressure-sensitive adhesives are used by removing a protective liner and pressing an object into the adhesive to secure it. This material is often used in PCB applications to secure a portion of a circuit in place without soldering.
• Shielding: Electromagnetic interference has historically been a problem, especially in applications where electronics are particularly sensitive to interference. Improved shielding technology has made this less of an issue in recent years, reducing noise and controlling signal line impedance.
• Stiffeners: FR4 and polyamide stiffeners are often added to flex circuits in areas where the circuit may need more support, such as connection areas. This improves the strength and longevity of the circuit.

Engineering Services

The advantages of working with MCL for PCBs extend far beyond the cutting edge specs, tolerances and advanced features of our boards. We are proud to provide several engineering services to help your business meet its quality and performance needs:

• Design for Manufacturability: Our design-for-manufacturability (DFM) capabilities mean we can engineer PCB solutions that optimize every manufacturing step from fabrication to assembly to testing and delivery. Taking advantage of these capabilities means you’ll get quality, reliable PCBs quickly and be able to ensure client satisfaction.
• Design Rule Check: Our design rule check (DRC) capabilities also mean we can double-check each chip layout to ensure it abides by the necessary parameters and design rules. Our strategic manufacturing partners will be better able to maximize the use of space, and you’ll receive high-quality boards that perform well in their intended applications.
• Controlled Impedance Modeling: When your business requires controlled impedance in its PCBs, we can perform controlled impedance modeling and then adjust the copper thickness and the physical relationships between the board components as needed. That way, we ensure high-quality boards that can run between 100 MHz and 3 GHz range.
• Panelization: PCB panelization, which arranges several individual PCBs is into a single unified panel, is often a critical engineering step because it increases accuracy during automated assembly and helps ensure quality boards. At MCL, we offer panelization for anything from traditional rectangular PCBs to polygons and other more intricate designs.
• DFX-to-Gerber Conversions: Some businesses have DFX files that computer-aided design (CAD) programs have generated for them. If your company has DFX files, you’ll likely need a way to convert them to more standard, flexible and efficient Gerber files. MCL can convert your files easily to provide you with faster delivery times and minimize production errors.

Flex PCB Applications

A flex PCB is essentially the same thing as a non-flex board except the flexible PCB uses a flexible base material to make its circuit connections. This is most helpful for products that will likely not be stationary devices. The durability and size of flexible PCBs, as well as the shrinking sizes of electronics, have resulted in their adoption by a growing number of industries. Just a few of these industries and applications include the following:

• Automobiles: With the automotive industry increasingly turning toward electronic components, circuits that can handle the vibrations and stresses of a vehicle’s interior are more important than ever. A flexible printed circuit board offers a valuable option for the industry, providing a durable yet cost-effective option.
• Consumer Electronics: Flexible PCBs are typically used in small electronic products like cell phones, tablets, cameras, video recorders and other similar smaller gadgets on the market today. These products may be transported or handled regularly, making the flexible PCB’s resistance to shock and vibration a useful feature.
• High-Speed Digital, RF and Microwave Applications: The reliability of flexible PCBs makes them ideal for handling high-frequency signals.
• Industrial: Industrial electronics often handle massive amounts of vibration and stress, so flexible PCBs with shock absorption and anti-vibration capabilities are a must.
• LED: LED lighting is massively popular today in both residential and commercial applications. This is primarily because of LED technology’s incredible power efficiency. Heat is often the only concern, which can be mitigated with a flexible printed circuit board and its effective heat transfer properties.
• Medical Systems: Small and dense electronic designs are becoming increasingly important in the medical industry, with handheld surgical technology and even electronic implants growing in popularity. Flexible PCBs can be applied in both cases, meeting the durability and size requirements of surgical technology and the necessary flexing ability for implants.
• Power Electronics: Another benefit of a flexible printed circuit board is that it can be coupled with highly flexible, thin layers of copper, which means the board can handle heavier power currents. This is especially important in devices that will require more power to operate at full capacity, like those found in the power electronics industry.

Flex printed circuit boards can address most of the issues facing today’s engineers. If you’re looking for an improved stretch, broader flexibility and simple use with leading packaging changes, it’s time to talk to us about flexible PCBs. Whether you need single-sided flex boards or multi-layer boards, we ensure your finished product will be of the highest quality.