One-stop Service Flexible PCB: The Ultimate Guide


Oakley Mae

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Hiring the services of a one-stop service flexible PCB provider brings you a step closer to actualizing your project.

Producing flexible PCBs entails designing, manufacturing, assembling, and testing. 

How much time would you waste to go with different service providers for each production step?

Additionally, you’ll find it easier to bargain for better deals if you leave the whole production to one company. 

But is doing so beneficial in the long run?

Well, read on to find out.  

Table of Contents

Why Customers Choose One-stop Flexible PCB Service

A saleswoman talking to a customer

(A saleswoman talking to a customer)

A flexible PCB is a printed circuit board made from flexible materials that allow it to bend and twist to fit into tight spaces.

Additionally, the flexibility will enable it to conform to various shapes without losing its mechanical and electrical properties.

On the other hand, a one-stop service provider offers flexible PCB services straight from design, manufacturing, and assembly.  

Design Services

One-stop flexible PCB service providers design circuit boards to meet an application’s needs.

Additionally, they ensure that it meets the industry standards and regulations regarding circuit boards.

Their work includes layout design, selecting materials, and optimizing the board for a particular use. 

Manufacturing Services

After the design, using several techniques, the next step is manufacturing the PCB according to your needs.

Some include laser cutting and roll-to-roll manufacturing.

Furthermore, it’s at this stage that they select the best substrate materials for your board. 

Assembly Services

Once the one-stop service manufacturer completes manufacturing the bare PCB, the next step is mounting components.

They attach resistors, capacitors, and integrated circuits (ICs) onto the board. 

Remember, the components they use at this stage rely on the type of manufacturing process.

For instance, Surface Mount Technology (SMT) components have different attachments from those of through-hole technology. 

Therefore, customers generally prefer a one-stop service for flexible PCBs to guarantee that they are getting a high-quality product.

Moreover, a single manufacturer will optimize production to save resources and reduce errors.

Surprisingly, relying on several manufacturers will lead to delays in production which may lead to poor-quality circuit boards.

Flexible Circuit SMT Production Process

SMT assembly line for flex PCBs

(SMT assembly line for flex PCBs)

Unlike rigid circuit boards, you can only install surface mount components onto a flexible circuit board.

The first step in the production process is the fabrication of the flex circuit boards. 

You will begin with cutting lamination, generating circuits on an FCCL, adding a surface finish, and doing an automatic optical inspection (AOI).

Afterward, cut the coverlay, add lamination, print the silkscreen, and do a test to ascertain your board’s functionality. 

The second step involves baking flex PCBs you have kept in storage for too long.

Remember, this step is unnecessary for new PCBs as the substrates are still moisture free.

And common substrates like polyester and polyimide absorb moisture if left for long durations. 

Thirdly, add jigs to facilitate easier and more accurate mounting of the surface mount components.

Flexible PCBs roll easily; hence, installing components without relying on jigs will be hard.  

Fourth, place the SMT flex board in a solder printing machine that relies on the program that you feed in.

In this step, the machine spreads glue on the board before mounting the components. 

Fifth, depending on the application, you can opt to thermally laminate your circuit board with nickel sheets and black films. 

Flex PCB Testing, Inspection, and Sub-Board

Flying probe test in a PCB factory

(Flying probe test in a PCB factory)

After production, testing is the next stage in making a functional flex PCB.

Moreover, you can’t do an AOI test on a flexible circuit board as it has less than ideal dimensional stability.

Here are the various tests you must do on your flex circuit board. 

  • Tension test: A tension test is important since the flex PCBs twist, bend, and move in many directions during installation and use. Consequently, it is subject to stress and tension, which may damage its mechanical and electrical integrity. We use an electrical tension tester to know its elastic limits during testing. 
  • Bending test: A bending test determines whether a flex PCB assembly has sufficient bending radius to match its application requirements. 
  • Button strike life testing: If your flex PCB assembly has buttons, use a button strike life tester to know the strikes it can withstand. 
  • Salt spray test: Conduct a salt spray test using your PCB assembly module in high-salinity areas such as seashores. 
  • Bridge testing: Bridge testing helps determine a board’s conductance, capacitance, and resistance. 
  • Environmental protection test: It is a general test on circuit boards that you plan to use in areas with a wide temperature range. Consequently, you’ll know how much temperature your board can withstand before critical components fail. 
  • Hand sweat test: You’ll inevitably touch your flex PCB at one point during the manufacturing process. The hand sweat test confirms that the circuit board is still operational after contact with human hands. 

Flexible Circuit Board Assembly Production Equipment

A PCB infrared soldering oven

(A PCB infrared soldering oven)

Generally, flex circuit board assembly types of equipment are surface mount technology tools.

For instance, the SMT pick and place machines that manufacturers employ for high precision, high-speed placement of components. 

Other pieces of equipment include SMT stencil printers and reflow ovens for soldering components onto a flex PCB.

Additionally, you’ll need curing machines that work well with coating machines and inspection systems. 


What are the flex PCB anti-static requirements?

Anti-static requirements are steps flexible PCB manufacturers undertake to prevent static electricity from destroying critical electronic components.

Generally, static electricity results when you rub two surfaces against each other, leading to a charge build-up.

To prevent such from happening, manufacturers undertake the following anti-static requirements.

First, use anti-static tools and grounded workstations to ensure that all static charges discharge to the ground.

Second, wear anti-static clothing to prevent unintentional charge build-up.

Third, package your flexible PCBs using anti-static packaging.

Fourth, ground the welding tools sufficiently and test them for any charges before commencing the welding process. 

What are the flexible PCB soldering requirements?

Soldering surface mount components can be tricky, especially if you’re new to the game.

For instance, you must ensure the solder joints are smooth, and the components lie flat on the board’s surface. 

Moreover, the solder should be less than two-thirds of the solder end’s height.

Also, ensure that single-sided boards have solder climbing pins with a height greater than 1mm. 

Conversely, double-sided circuit boards should have solder climbing pins of height 0.5mm or greater.

Another requirement is that the solder joint should be conical in shape and spread over the whole pad area.  

How do you transport flex PCBs?

Flexible printed circuit boards are delicate, and you must transport them in a way that limits the damage.

Consequently, use the following packages during transportation.

First, use an anti-static container with anti-static pearl cotton isolating material. 

Second, space your PCBs so they are no less than 10mm from adjacent boards and the box.

Third, keep a placement height of no less than 50mm between the top surface of the flex PCB and the lid. 


In conclusion, fabricating a flexible board is way more complex than developing a rigid board.

The main contributing factor factors are the high-quality materials and complex fabrication equipment.

Surprisingly, any mistake in something as simple as the bend radius could result in problems. 

Therefore, approaching a one-stop service provider can present a long-lasting solution.

In most cases, these provider helps customers save resources and time.