Your Reliable Flexible PCB Manufacturer Over 12 Years

There are four different types of flexible PCBs in the PCB industry. All four are used for different applications. The types are as follows.

Single Layer Flexible PCB

When the PCB contains only one conductive layer on the dielectric film of the flexible board, that is a single layer flexible PCB. We place the electric components on either side.

Double Layer Flexible PCB

There are conductive layers on both sides of this kind of PCB. We can place the electrical components on any side of the PCB.

Multilayer Flexible PCB

They’re more than three conductive layers for multilayer flexible PCB and also many applications for it.

Besides, rigid-flex PCB, HDI flexible circuit boards are worthwhile for different sectors.

Flexible HDI PCB

Flexible PCB has some unique features which make it stand out from others. These special features of this PCB make them extraordinary. The features are like:

Small

Flexible circuits are usually small in size which makes them compact. The product volume reduces as the circuit is small.

Thin

Flexible circuits are usually very thin. For the thickness, the PCBs are very soft. The three-dimensional assembly is also strengthened for this fact.

Thin Flexible Circuit Board

Lightweight

Flexible circuit boards are very light in weight. It helps to decrease the product weight which is great.

Short Lead Time

Lastly, the assembly time is very short. We can easily configure all the lines and get rid of the unnecessary cables.

Materials that are flexible and moveable are used to manufacture flexible PCBs. Its flexibility allows it to turn or move without causing irreversible harm to its components or connections.

Each component of the flexible PCB has to operate together to be effective.  You will need a variety of materials to put together a flexible board.

Cover Layer and Substrate

The conductor carrier and insulating medium determine the substrate and film’s functionality. Additionally, the substrate must be able to flex and curl.

Polyimide and Polyester sheets are often used in flexible circuits. These are just a few of the many varieties of polymer films you may get, but there are many more to choose from.  Because of the low cost and high substrate quality, it is the better choice.

PI polyimide is the most often used material by manufacturers. Thermostat resin of this type can resist extreme temperature. Thus, melting is not a concern.

After thermal polymerization, it retains its elasticity and flexibility. Besides that, it has excellent electrical properties as well.

Conductor Materials

You must choose conductor elements that will carry the electricity most effectively. Almost all flex circuits employ copper as the primary conductor.

In addition to being a highly excellent conductor, copper is also relatively easy to get. Copper is a bargain compared to the price of other conductor materials.

Electrical conductivity is not enough to dissipate heat effectively; it also has to be a good heat conductor. Flexible circuits may be made using materials that will reduce the amount of heat they generate.

Adhesives

Between the polyimide sheet and the copper on any flexible circuit boards are adhesives. Epoxy and acrylic are the two primary kinds of adhesives you have at your disposal.

A strong adhesive is needed to handle the high temperatures generated by the copper.

Insulators

Insulators prevent electric shocks from flowing through copper or other conductors and onto the user. The best insulator is polyimide film, which is made from polyimide polymers.

Flexible PCB Materials

A flexible PCB is a PCB with a wide range of functions. Here are a few examples:

• There are no restrictions on how it may be twisted, wrapped, or folded, so it can be organized in any way that best suits the needs of the particular space.
• It is simple to assemble and solder.
• It is small and light in weight,
• They can function in cold or high temperatures.
• They are a less expensive alternative to rigid PCBs.

Highly Functional Flexible Circuit Board

You can use flexible PCBs in a wide range of applications. The following are only a few examples:

Commercial Electronics

Computer technology accounts for a third of flexible printed circuit sales volume. This includes printers, intelligent devices, and much more. Flex PCBs are vital in keeping up with the market’s need for smaller, more sophisticated portable devices.

Automotive

Vehicles are the second-largest market for flex PCBs. Since the beginning of this decade, the ordinary automobile has seen a dramatic change in appearance and its technological capabilities.

To accommodate the increasing number of sensors and electronics in automobiles, flex PCBs provide both space allocations as well as thermal properties.

Aerospace

Due to its extraordinary capacity to withstand severe temperatures and vibration, flexible PCBs are ideal for space applications like satellites. As a result, they can take on a variety of forms that are ideal for spaceships and replace connections that are more susceptible to failure.

Health Care Equipment

Wearable medical gadgets have grown more important in recent decades as medical technology has advanced. Flexible boards are used in various products to provide excellent performance that can withstand daily usage. Because they may mimic the contour of the body, flexible PCBs improve the endurance of these devices.

Widely Used Flexible Printed Circuit Board

Flex PCBs provide these benefits, making them excellent for various sectors. This includes military, medical, transport, electronic goods, automotive, communications, aviation, and industrial.

Flexible PCBs can provide a variety of advantages, including:

Less Space

Compared to traditional circuit board assemblies, flexible PCBs take up around 10% of the area and weight, allowing for more flexibility in installation and packing. Due to the inherent flexibility, the bends may also be made more tightly.

Highest Reliability

There are fewer interconnects on flexible printed circuits, which means fewer solder joints and contact crimps. Flexible PCB boards are more reliable since they do not have as many possible causes of failure.

Enhanced Performance

Various connections and components may be attached to the flexible PCB, including ZIF connectors. They can also withstand high and low temperatures, radiation, and toxins with ease.

Reduced Prices

Flexible PCBs save money by reducing material and packaging needs, component replacement costs, and assembly faults that need repairs.

Flexible PCB Advantages

There are several kinds of flexible printed circuit boards available on the market. Each type has a particular layer responsible for carrying out its activity.

One layer is included on both the single-sided and double-sided flexible boards.

Flexible PCB Operating Principle

Multiple copper layers are sandwiched between dielectric layers on a multilayer flexible circuit board, which is generally joined via a plated through-hole connection. Depending on the application, multi-layer circuits may be manufactured with or without cover layers.

Single-layer flex PCB is used for light applications, whereas multilayer PCB is used for heavy applications that need greater power.

Multilayer Flexible Circuit Board

A single-layer flexible PCB consists of the following elements-

• Dielectric Materials
• Metallic coatings
• Conductors
• Epoxy resins
• Adhesives

Flexible PCB Structure

A well-manufactured flexible printed circuit promotes the device’s quality to a great extent. Its entire manufacturing is a lengthy work that is divided into various parts. You need to maintain supreme quality in each step of manufacturing for optimizing this circuit board.

Now, we are going to explain all the steps of a flexible PCB manufacturing process for your convenience.

PCB Layout Design

First, you need to draw a schematic of this PCB. It is the outline of your circuit board design. Then, design the PCB layout by using reliable design software. Nowadays, various design software is used in designing flexible circuit boards.

Flexible PCB Design

Then, you have to convert this design file into Gerber format. The Gerber file contains all the required information related to PCB manufacturing. Besides, it is important to conduct a design rule checking for finding faults in the design.

After completing the checking, send the file to the manufacturer to handle the further steps. KiCAD flexible PCBs are reliable in terms of design.

Printing

In this stage, the flexible circuit board laminate needs to wash. Then, it receives the photoresist that is composed of photoreactive chemicals. A UV-ray is dropped upon this board to perform the printing process.

After preparing, the circuit board should be washed with proper liquid.

Initial Etching

Etching means eliminating unwanted copper from the PCB laminate. Here, the flexible PCB board covered with photoresists goes through a copper solvent bath. Then, the unmasked coppers get washed.

Alignment of PCB Layer

After a successful primary etching, it is required to align the PCB layers. An automated optical inspection can be run for checking this layer alignment and other features of this PCB.

Laminating Of Layers

In this segment, you need to laminate PCB layers. The outer PCB layers should be connected to the substrate.

PCB Drilling

Now, it is time to drill holes on the stack PCB board. Here, maintaining the hole diameter and drilling speed concerning the shape of PCB components is essential. Usually, an X-ray is used in finding the proper placement of drilling.

Copper Coating

After drilling, a copper coating is applied to fill up the drilled holes. Besides, plating binds the layers together. Then, image the external PCB layers by applying photoresists once again.

Final Etching

Then, the board is placed in a toxic Ferric Chloride solution. It reduces unwanted coppers again. In this case, you must cover the necessary portions through a protective mask.

Watch this video to know more about etching:

Application Of Solder Mask

In this stage, cover the board with solder mask ink. Then, apply a solder mask on both sides of the flexible circuit board.

PCB Surface Finish

Surface finish is a reliable technique for improving solderability and protecting the PCB surface from corrosion. In this part, a suitable metal is coated on the copper layer according to the requirement of electronic devices.

Electrical Testing

In the end, an electrical test along with a functional test is conducted. It ensures an error-free flexible circuit board assembly. Then, the last thing is cutting the circuit board from the panel.

This is the basic manufacturing process of flexible PCB. You can find some variations concerning the consumer’s demand.

Flexible circuit board manufacturers utilize high-quality surface treatments to extend the service life of these critical components over time. In terms of surface finishing, ENIG is the most extensively employed procedure out of the many options.

Other surface finishes are used, such as immersion silver, immersion tin, hard gold, etc.

ENIG

A tiny coating of gold is electrolytically plated over nickel in electro gold flash plating.

This sort of plating is very tough and long-lasting. It has a prolonged shelf life, which may endure for many years. Despite this, its long shelf life and durability make it more costly.

Immersion Silver

Immersion silver has no adverse effect on copper. However, exposure to the elements will cause it to tarnish.

As a result, anti-tarnish packing is required.

It will remain solderable over 6-12 months if properly packaged. A day after unpacking, the PCB has to go through a process known as “solder reflow”.

Flexible Circuit Board With ENIG Plating

Well, there are some important facts to consider while building the flexible printed circuit board. The building concerns are something that we can not escape. The facts are as follows.

Ground Plane

If we make some ground planes on the circuit board, it will ultimately decrease the product weight. It also helps the board to have better flexibility.

We have to create some holes as we head to apply fileting on the board. It should be only applied where the pad area is increased to split up stress.

Routing

The routing process is simple. If we do the routing properly, then the circuit board stress decreases. The proper routing also enhances the folding and bending features.

Flexible PCB Building Concerns

Etching

We do etching for a PCB in order to make up for the isotropic losses. The thickness of the copper foil should behalf as the loss of the line width. several conductor types, etch marks, etc mainly causes the line width.

Conductor Size

As the conductive material on the PCB, we usually use thin copper. The light copper makes the circuit flexible and enables the circuit to be perfect for a wide range of applications.

From their names, flexible rigid PCBs vary. The main distinctions between rigid PCB vs flexible PCB are-

Flexibility

Flexible circuits can be shaped to match the eventual application by folding or creasing, allowing the designer to customize the circuitry. Wearable electronics benefit from flexible circuits. Rigid PCBs take up more space than flexible PCBs.

Reduced weight

Due to their low weight, flexible circuits are useful for unmanned vehicles.

Durability

Flexible PCBs absorb vibrations far better than rigid PCBs while being thicker and more robust. This improves product life, dependability, and functionality.

Resistant

Heat, chemicals, and radiation may damage or distort rigid PCBs, whereas flex PCBs are far more robust. This explains their widespread use in modern car electronics.

Rigid PCB

Yes, they are supportive of customization to a certain level. If you don’t get the desired output through standard PCB designs, you can customize the circuit board according to your requirement.

Usually, flexible printed circuits allow customization of the board thickness, design, layer count, copper thickness, etc.

Customized Flexible Circuit Board

Using a flex PCB is advantageous in several ways. However, there are also some drawbacks. Let us give them a little of the spotlight.

• A higher price for materials than rigid PCBs
• Assembly is a complex and time-consuming operation.
• Damaged by scratches and dents when not properly shielded
• Correct storage practices are needed
• Relatively hard to fix

Stable Flexible PCB Board

You must consider the following issues while designing a DIY flexible PCB.

• The Thickness
• Flexible PCB Connectors
• Bending Radius
• PCB Routing
• Bend Ratio
• Surface Mount Technology Access
• PCB Via Placement
• Aperture ratio

You can watch this video to know more about PCB designs:

A skilled expert is needed to produce high-quality flexible printed circuits that perform as intended. Before placing an order for a Flexible PCB from a manufacturer, you should consider the following:

Quality

Quality is essential, just like anything else. First and foremost, you should consider quality while purchasing flexible PCBs. Your flexible circuits should have superior quality products and services, a high-speed layout, and good conductivity.

Standards and Certifications

The best flexible board manufacturers meet UL, ISO, & IPC requirements. When looking for PCB manufacturers, ensure they are accredited and follow certain laws and regulations.

Cost

Before making purchases, you must establish a balance between quality and cost. Almost all PCBs have a cost that varies with quality and design. Conditions like solder masks and base material might vary. These will have a significant impact on the ultimate product pricing.

Test

Flexible boards must be tested to ensure their functioning and integrity.

Flexible PCB has brought out an amazing development in the electronic world. As modern electronic products tend to be smaller day by day, flexible printed circuits significantly improve the design quality.

Besides, their reliability and functional properties are beyond question. If you are looking for a flex PCB manufacturer, contact PCBMay immediately. We offer custom solutions of various flexible circuits that can meet your demands.

In this guide, we tried to explain all the concepts in a simple manner. If you have more queries, contact us any time. Get in touch with us for more updates about the PCB world.