High-Quality Flex PCB Fabrication, Applications, Types, and Benefits

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Oakley Mae

There is a slight difference between a flex PCB and a high-quality flex PCB.

Generally, a high-quality flex PCB is just a flex circuit board with high-quality materials and features that produce high-quality performance.

Additionally, they have excellent electrical performance, high reliability, and support high-density applications.

Surprisingly, everything in these circuit boards is “high.” 

Read more on high-quality flex PCB fabrication, applications, types, and benefits. Let’s get started. 

Table of Contents

Understanding High-quality Flex PCB

PCB technology

(PCB technology)

High-quality flexible PCBs are just flexible boards with high-quality materials and features that offer high-quality performance.

Everything in these circuit boards is high, including durability and environmental stress resistance. 

The good thing is that you can bend them to greater limits without damage.

Surprisingly, the board is lightweight, boasts vibration resistance, and is more cost-effective. 

Types of High-quality Flex PCB

Someone holding a plastic flex PCB

(Someone holding a plastic flex PCB)

There are several types of high-quality flex PCBs: adhesive-based, single-layer, rigid-flex, double-layer, multilayer, and copper foil.

Check out each type below: 

Single-Layer Circuits

This circuit board has one copper layer between polyimide dielectric.

Also, holes in the base film allow component leads to pass through to connect layers.

Surprisingly, the circuits have coverlay to protect the copper surface from destruction. 

Multilayer Flex Circuits

Multilayer circuit boards combine several circuit board layers intending to address impedance requirements.

Surprisingly, these boards also remove crosstalk and unavoidable crossovers, thus finding key applications in high-speed applications. 

A common advantage of multilayer circuits is the high flexibility that supports high-density components without a single wiring.

The boards have an efficient airflow prolonging the overall life cycle.

Further, they consume limited spaces by using a thin, flexible dielectric and eliminating the need for wiring. 

Another advantage is the high flexibility experience in high-quality flex PCB surpassing traditional boards.

We saw these boards gain many military applications but have since been adopted for commercial uses. 

Double-Sided Circuits

From their name, these circuits have two copper layers.

Additionally, the circuit board has extra elements like pins, connectors, and stiffeners.

Therefore, common applications of these circuits include: 

  • Digital cameras and LCD modules
  • High-density surface mount applications
  • Shielding applications

Rigid-Flex Circuits

Lastly, we have rigid-flex PCBs that borrow from features of rigid and flex circuits.

Surprisingly, they’re mainly designed with multiple flex layers linked to a single rigid layer.

However, these boards are difficult to connect since everything must happen in 3D space.

Fortunately, it yields boards with higher efficiency. 

Adhesive-Based Circuits

Flexible circuit boards have adhesives that bond the substrate layer and copper traces.

Most high-quality flex circuit boards are 0.0001-0.10 inches thick. Surprisingly, the adhesive thickness is, in most cases, equal to the copper thickness. 

Copper Foil Flex PCBs

High-quality circuits use rolled copper foil with excellent tensile strength, enough half-softening temperature, and a suitable flex fatigue property.

Manufacturers prefer copper due to its high conductivity and low surface oxygen content that limits oxidation. 

Surprisingly, you can choose between electrodeposited and wrought copper foil materials.

Although rolled copper foil has been used for a long time, the thinner electroplated option is slowly gaining ground and catching up. 

Benefits of High-quality Flex PCB

A PCB in a telephone

(A PCB in a telephone)

We expect high-quality flex PCBs to live up to their name’s hype and offer customers high-level functionality. Let’s consider its benefits below. 

Cost-effectiveness

One thing about high-quality flex PCBs is their cost-effectiveness, with the actual PCB cost depending on several factors.

First, it depends on the total conductive layers, with multiple-layer circuits costing almost double than single-layer options. 

The cost will also depend on extra processing steps and the high material costs.

Therefore, you must optimize the PCB layers with a high layer count translating into higher costs.

Regarding material selection, we prefer thermal adhesives as opposed to pressure-sensitive adhesives.

The former is flexible epoxy and acrylic resins, thus giving a more permanent and cost-effective bond. 

Weight Savings

One of the main benefits of flex circuits is that they eliminate wire connections and the need to wrap circuits.

Therefore, you’ll witness reduced assembly rejects and in-service failures.

Generally, the circuit boards have reliable connections that offer more durability. 

Surprisingly, these boards are very thin and about 20% lighter than rigid boards, thus supporting the development of lightweight electronics.

And this is why we have them in high use in wearables like smartwatches. 

Vibration Resistance and Environmental Impact

Vibration problems are common in rigid boards that don’t absorb any stress when under an impact.

However, high-quality circuit boards are meant to change shape and form, and even with the greatest stress and vibrations, they’re unlikely to experience damage.

Therefore, they find common applications in control panels and automotive dashboard systems. 

They are also common in industrial applications since they’re robust, small, and can comfortably handle chemicals and UV exposure.

Finally, since they dissipate heat effectively and are designed to withstand high temperatures, we use them in industrial sensor technologies. 

Applications of High-quality Flexible PCB

Photograph of hard drive PCB

(Photograph of hard drive PCB)

As highlighted, flex circuit boards have narrow line widths and higher heat dissipation.

Also, they function better over a wider temperature range.

Surprisingly, the polyimide materials in the board provide top-notch RF absorption and EMI shielding.

All these properties make the circuit board perfect for use in the following applications: 

Flexible Silicon Technology

Recently, we have seen an increase in silicon materials and chips, focusing on nanoscale structures, printed thin films, and flexible silicon fabric.

Surprisingly, the contribution made by this technology has only given rise to high-performance electronics and systems. 

Medical Equipment

Flex circuits have form-adaptive properties that help them fit tighter spaces that rigid boards can’t.

Therefore, manufacturers use such advantages, for example, to create devices that can get into the human body and scan critical organs. 

Automobiles

Flex circuit boards have made tremendous progress in the automobile industry, especially in eliminating assembly errors.

Also, they play a critical role in meeting the ever-rising weight, cost, and reliability demands.

And even in the future, we expect them to help improve driver comfort and safety. 

Printers

Look at your printer, and you’ll see a polyimide-based flex circuit tape printhead.

This makes the board very effective. 

Additional high-quality flex board applications include: 

  • Disk drives
  • Computers
  • LEL constructions

Materials Used To Fabricate High-Quality PCBs

High-quality PCBs use quality materials to improve the performance and durability of the designs.

Check out these materials below: 

  • A substrate overlay might include polyester, polyimide, PTFE, or aramid. 
  • Copper is the main conductive material.
  • Epoxy or acrylic adhesives
  • Insulators, which include polyimide film, prepreg, or FR-4.
  • A solder mask layer
  • A surface finish that includes immersion tin, gold, or immersion silver. 

FAQ

What are desirable PCB qualities?

A good quality circuit board should have the following: 

  • High-quality base materials
  • A tolerant copper clad based on international standards
  • Impeccably clean without dust or dirt
  • Well-defined via tracks, drill hole tolerance
  • Industry-standard solder-resistant material
  • The right hole wall thickness
  • It should be without track cuts

How do you guarantee high-quality PCB design?

Developing a high-quality circuit board is difficult without the right skill set and equipment.

However, everything becomes possible if you do the following: 

  • Maintain proper signal and power integrity
  • Select the proper parts and equipment
  • Follow design rules strictly
  • Choose the right board materials
  • Approaching the best manufacturers

Conclusion

This article has almost touched on everything relating to high-quality flex boards.

Most importantly, it would help if you understood that these boards use high-quality materials and features to produce high-quality performance and durability.

In short, everything about these circuit boards smells of “high” quality and performance. 

Moreover, you can employ these boards in printers, automobiles, medical equipment, and flexible silicone technology if you’re an engineer.

Generally, they guarantee high flexibility, weight savings, cost-effectiveness, and vibration resistance.