Why Do Flex PCBs Excel in Medical Device Applications?

By | Date posted: | Last updated: March 26, 2024
Flex PCBs for Medical Applications

In the world of gadgets, flexible printed circuit boards (Flexible PCBs) hold the utmost importance for electronic designs. Unlike regular ones, these special boards can bend and flex, making devices more creative. They’re like the puzzle pieces that connect all the electronic parts together. This article explores why flexible PCBs are so useful, looks at where they’re used in real life, and checks out what might happen with them in the future. To know more about it, continue reading.

Understanding Flexible PCBs

Flexible printed circuit boards can be considered the gymnasts of electronic components. Unlike their rigid counterparts, they possess a remarkable ability to bend and adapt to different shapes, enabling more versatile designs in electronic devices. These boards are made from electrically conductive materials, allowing seamless connections between various electronic components. The flexibility of these PCBs opens the door to a new era of design possibilities. In essence, flexible PCBs offer a dynamic and adaptable foundation for the intricate electronic systems that power our modern world.

Advantages of Flexible PCBs

Flexible printed circuit boards bring a myriad of advantages to the table, making them a preferred choice in modern electronics.

  • Flexibility and Adaptability: Like a contortionist, flexible PCBs can bend and flex, allowing them to fit into spaces where rigid boards wouldn’t stand a chance. This flexibility enables innovative and space-efficient designs.
  • Space-saving Marvels: Compact and lightweight, flexible PCBs contribute to the miniaturization and expand lifetime of electronic devices. They are the go-to solution for applications where space is a premium, allowing for more efficient use of every square inch.
  • Durability and Reliability: Designed to withstand the rigors of bending and flexing, these boards offer robust durability, ensuring reliable performance even in challenging conditions.
  • Seamless Connectivity: Electrically conductive materials in flexible PCBs enable smooth connectivity between electronic components, reducing the need for complex wiring.

Also Checkout: Flex Printed Circuit Board Cost

What Are Flexible PCBs Used For?

In the changing world of medical devices, the role of flexible rigid printed circuit boards is crucial. These small electronic powerhouses help make devices smaller, meeting the evolving needs of the industry.

  1. Medical Wearables: Flex PCBs find application in a variety of wearable health-tracking devices, such as blood glucose monitors, body temperature monitors, blood pressure monitors, heart monitors, etc.
  2. Implantable Medical Devices: These refer to devices designed to be inserted into the human body, benefiting from the flexibility of PCBs for integration. Flex PCBs are used in various implantable medical devices such as pacemakers, neurostimulators, implantable cardiac defibrillators, and cochlear implants.
  3. Hearing Aid Devices: Flex PCB designs enable the integration of microphone, digital signal processing (DSP), and battery components into a compact unit that fits discreetly behind the ear.
  4. Diagnostic and Medical Imaging Equipment: Flex PCBs are utilized in diagnostic and monitoring equipment such as ultrasound machines, MRI scanners, CT scanners, X-ray machines, and radiation treatment. The flexibility of Flex PCBs allows for compact and lightweight designs, which are crucial for portable and handheld diagnostic devices.
  5. Remote Patient Monitoring Devices: Flex PCBs play a crucial role in these systems by offering the requisite flexibility and resilience to endure frequent bending and flexing, all the while facilitating compactness and cost efficiency. Notable instances of remote patient monitoring devices leveraging flex PCBs comprise wireless blood glucose monitors and wearable ECG sensors.
  6. Endoscopic and Minimally Invasive Surgery Devices: Flex PCBs are essential components in endoscopic cameras, catheters, and other minimally invasive surgical instruments. Their flexibility enables the creation of small, lightweight, and highly maneuverable devices that can navigate through the body’s intricate pathways with ease.

Also Checkout: The difference between Rigid PCB and Flexible PCB

Overcoming Design Challenges

Flexible Printed Circuit Boards navigate and conquer unique design challenges, offering solutions that traditional rigid PCBs struggle to address.

  • Compact Design Challenge: One of the most significant challenges in compact design is the limited physical space. Flexible PCBs overcome this hurdle by bending and flexing, allowing them to fit seamlessly into tight spaces without compromising functionality.
  • Environmental Challenges: Traditional rigid PCBs may struggle in environments with vibration or constant movement. Flexible PCBs, however, excel in such conditions, providing reliability and durability in challenging environments.
  • Integration in Small Devices: As devices become smaller, integrating traditional rigid PCBs becomes challenging. Flexible PCBs eliminate this challenge by conforming to the shape and size requirements of the device, enabling compact designs without sacrificing performance.
  • Reducing Complex Wiring: In applications where, intricate wiring is a concern, Flexible PCBs offer a solution. Their design allows for seamless connectivity between components, reducing the need for complex wiring structures.
  • Conforming to Unique Shapes: When a design requires a non-traditional shape, rigid PCBs may not be feasible. Flexible PCBs, however, offer the freedom to bend and shape according to the unique requirements of the design.

Future Trends and Innovations

As technology advances, the trajectory of Flexible Printed Circuit Boards (Flexible PCBs) points towards exciting trends and innovations that will shape the future of electronic devices.

  • Miniaturization and Integration: Continued emphasis on miniaturization, driving the development of even smaller and more flexible PCBs. Integration of flexible components directly into device structures for enhanced compactness.
  • Advanced Materials: Ongoing research explores new materials with improved flexibility and conductivity. Innovations may lead to flexible PCBs with enhanced thermal management and electrical performance.
  • Internet of Things (IoT) Connectivity: Increasing Integration of Flexible PCBs in IoT devices. The flexibility of these boards aligns with the diverse form factors and space constraints prevalent in the expanding IoT landscape.
  • Biocompatible Applications: Exploration of biocompatible materials for flexible PCBs, making them suitable for medical implants and healthcare devices. This innovation could open new frontiers in wearable medical technology.
  • 3D Flexible PCBs: Evolution towards three-dimensional (3D) Flexible PCBs, allowing for more intricate and space-efficient designs. This trend holds promise for applications in robotics and complex electronic systems.
  • Stretchable Electronics: Research into stretchable electronics, where flexible PCBs can conform to dynamic shapes. This innovation holds potential in applications requiring flexibility in motion, such as in soft robotics.

Also Checkout: Select the best Flex PCB Manufacturer


In conclusion, flexible printed circuit boards emerged as the key to revolutionizing electronic design. Their adaptability addresses real-world challenges, making them indispensable in medical, automotive, and IoT applications. Future trends forecast even smaller, more versatile boards, promising a dynamic landscape in electronics. Moreover, flexible PCBs are not merely components but architects of a connected, flexible future. As we navigate this ongoing journey, the potential for innovation remains boundless, ensuring that flexible PCBs continue to play a transformative role in the ever-evolving realm of electronic devices.

At Technotronix, we have over 44 years of fabricating and assembling a wide variety of flexible circuit boards. With state-of-the-art equipment, we deliver the flex circuit boards that you can rely on. No matter how complex your requirement, you can count on us to deliver to your bespoke needs. Our stringent quality control processes ensure that the boards deliver to your benchmarks. To know more about our services, please reach out to sales@technotronix.us or request a quote for flex PCB fabrication.

Top Factors that affect the flex printed circuit board price!

By | Date posted: | Last updated: February 27, 2023
Flex PCB Price

It goes without saying that cost optimization is an important KRA when it comes to designing and manufacturing a PCB. It ensures that the overall project is price competitive and finds acceptability in the market place. What then are some of the cost drivers of flexible PCB board and how can they be controlled. Below is a detailed overview.

Major cost drivers of Flex PCB

The major drivers that impact the cost of Flex PCBs include:

  • Circuit Board Material
  • Number of Layers
  • Size & Shape of PCB
  • Spacing & Trace Width
  • Copper Foil thickness
  • Drill holes
  • Drill to copper distance
  • Type of Surface Finish
  • Type of Stiffeners used

Let us look at each of these Flex PCBs cost drivers in detail:

Circuit Board Materials

Typically, while rigid boards make use of FR-4 material that come at a lower cost, flex boards make use of Polyimide substrate that offer better thermal and electrical properties. In fact, when it comes to the choice of PCB material some of the factors that need to be taken into account include:

  • Using a material that offers thermal reliability if the board has to operate in a high temperature environment.
  • Ensuring that the material used can withstand physical stress.
  • Making sure that the material allows uninterrupted signal propagation.

However, a very important aspect is not to over specify the material requirements. That can significantly drive up your costs. For example, if the PCB does not have to operate in a high temperature environment, you can very well make use of polyester laminate as opposed to polyimide substrate. Similarly simple flex boards can make use of inexpensive materials that work well at lower temperatures.

Number of circuit board layers

As the number of layers in the circuit board increases, so does the cost. This is on account of a whole lot of processing issues such as aligning the layers, ensuring integrity of plated through-holes, issues related to lamination, and more. As a thumb rule, from 4 to 6 layers, there is an overall increase of as much as 30-40 percent.

Size & Shape

Typically, the larger the surface area, the higher the price. Also, PCBs in regular shapes tend to cost less than PCBs in unconventional shapes. With an unconventional shape the panel utilization reduces & the cost tends to go up.

As far as possible therefore, it is prudent to stick to conventional shapes such as square or rectangle.

Spacing & Trace Width

An appropriate PCB trace width ensures that the signals propagate & that there is no overheating. Where spacing is really tight, etching is far more difficult as well as cost intensive.

Copper Foil Thickness

The cost is directly proportional to the thickness of the copper foil. With thick layers the need for high prepregs during lamination, goes up. Whenever there is more than half an ounce of copper on the inner layers and more than 1 ounce on the outer layers, the overall cost tends to increase. Also, thicker copper layers increase the trace width. A word of caution here through – the thickness of copper layers shouldn’t be less than one-fourth of an ounce as that could lead to high processing costs.

Drill Holes

If the drill hole is very small in size, it increases the drilling duration & adds to the cost. It is therefore advisable to stick to standard drill hole sizes.

Drill to Copper Clearance

This refers to the distance of the edge of the drill hole to the nearest copper feature. The smaller this distance, the higher the cost. A typical drill to copper clearance is 8 mils.

Surface Finish

In choosing the right surface finish the product performance as well as the cost need to be kept in mind. There is a wide range of surface finishes that are available. From example ENIG is known for its reliability & the fact that it doesn’t tarnish. It also offers superior solderability but it comes as higher cost than several other finishes. Immersion tin, as a finish, for example is known for its optimum cost and performance though not so much for its durability.

Type of PCB Stiffeners

The importance of stiffeners cannot be overstated. They offer support o components and connectors besides ensuring heat dissipation. Typically, FR4 and polyimide are used. However, aluminum and stainless steel are also sometimes used although they add to the cost.

Also, it is important to remember that stiffeners can either be bonded with a thermally bonding adhesive or a pressure-sensitive adhesive. Thermal bonding adhesive are less expensive than their pressure sensitive counterparts.

Ways to Optimize Costs

While we have looked at the major cost drivers, some of the ways to optimize costs include:

  • Limit the number of layers.
  • Ensure that the panel utilization is efficient.
  • Make sure that the stiffener thickness is uniform.
  • Ensure that the number of vias are optimized.

To sum up

It is fairly important that areas for cost-optimization be identified in the design stage itself. Being sure of the choice of material, number of layers, choice of stiffeners, trace width and more, will go a long way in ensuring that the PCB manufacturing process is seamless and that costs are kept under check.

It is also extremely important to make the right choice of PCB contract manufacturer who is equipped with industry best practices to be able to offer optimized cost and a quick turnaround time.

Go with a Technotronix – a professional PCB manufacturer with more than 4 decades of experience and ISO 9001:2015, ISO 13485:2016 certified who is equipped with the necessary industry best practices. So, you do not need to undertake unnecessary trial and error beyond a point. Feel free to ask if you have any questions regarding flex circuit boards. Your satisfaction is our primary goal!

Standard 4-Layer PCB Stack-up: Design, Fabrication, and the cost of manufacturing!

By | Date posted: | Last updated: February 2, 2023
4-layer pcb stackup

With miniaturized electronic products becoming ubiquitous, the need for small circuit boards is on the rise. Multilayer circuit boards are therefore the order of the day. A 4-layer PCB stackup is becoming increasingly common. Let us look at the 4-Layered PCB in detail.

What is 4-layer PCB Stackup?

As its name suggests, a 4-layered PCB comes with 4 layers, these include a top layer, a bottom layer & 2 inner layers.

Of these 4 layers, 2 are signal layers, one VCC & the other GND.

Typically, the inner layers are used as power & GND, while the outer layers are used for routing of signals as well as for component placement. With the inner layers used as power and GND planes you can be sure that EMI emissions will be less, and the quality of signal will be robust.

4 Layer PCB Advantages

The 4-layered PCB offers several advantages, including but not limited to:

  • Improved routing of signals
  • Better EMI shielding
  • Improved thermal control
  • High assembly density
  • Lends itself to compact designs and to miniaturization

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Structure of standard 4-Layer PCB design stack up

There can be 3 ways in which these can be stacked up

Option 1

  • Top Layer – Signal Layer
  • Inner Layer 1- Power Layer
  • Inner Layer 2 – Ground Layer
  • Bottom Layer – Signal Layer

It is important to note that the less the distance between the power and the ground layer, the less will be the impedance.

Option 2

  • Top Layer – Power Layer
  • Inner Layer 1- Signal Layer
  • Inner Layer 2 – Signal Layer
  • Bottom Layer – Ground Layer

In this option, the power and the ground layer acts as a shield for the inner signal layers. However, on account of the distance between the power and ground layer, the plane impedance tends to increase.

Option 3

  • Top Layer – Signal Layer
  • Inner Layer 1- Ground Layer
  • Inner Layer 2 – Power Layer
  • Bottom Layer – Signal Layer

While this stack-up is like the first one, here the key signal layer is the top layer.

4-Layer PCB Stackup Thickness (Core and Prepreg Thickness)

4-Layer PCBs come with two types of Core & Prepreg thickness. The standard thickness is 1.6 mm (about 0.06 in) although 1.2 mm (about 0.05 in) is also commonly used.

We have already published article where you can check difference between PCB core and prepreg .

With a 1.6 mm (about 0.06 in) PCB, the core material is 1.2 mm (about 0.05 in) thick while the prepregs are 0.2 mm (about 0.01 in) each.

With 1.2 mm (about 0.05 in) thickness, there is a core material of 0.8mm (about 0.03 in), o.2 mm (about 0.01 in) of prepreg with coil and 0.2 mm (about 0.01 in) of prepreg with copper.

4 Layer PCB Manufacturing Process

Broadly the steps involved in manufacturing are as below:

  • #1. Clean up using the chemical method
  • #2. Lamination of the dry film
  • #3. Exposing and developing the image of the Inner Layers
  • #4. Copper Etching
  • #5. Strip Resist
  • #6. Layer up as well as bond with prepreg
  • #7. Layer up with Copper Foil
  • #8. Drilling
  • #9. Plating & deposition of copper
  • #10. Imaging of Outer Layer
  • #11. Copper Plating
  • #12. Tin Plating
  • #13. Etching
  • #14. Application of Solder Mask
  • #15. Applying the appropriate Surface Finish
  • #16. Application of Sun Screen
  • #17. Electrical Testing
  • #18. Profiling as well as V-Scoring

4 Layer PCB Cost

When it comes to the cost of a 4-layer PCB, there is not a standard cost as it depends on several factors. Some of these factors include:

  • The size of the board.
  • Material used. Here there can be variations from a standard FR-4 board to a high Tg material, which is more expensive.
  • Complexity involved in manufacturing. Typically, when the PCB has buried and blind holes, the complexity increases and so does the cost.
  • Thickness of copper.
  • Choice of Surface Finish. Typically, if finishes like Immersion Gold are chosen, the cost will increase.

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Sum up

It is important to make the right choice of PCB contract manufacturer who will be able to understand your bespoke requirements and fabricate your board according to your needs.

Technotronix is equipped with industry best practices. As a professional manufacturer with 40 years of experience who ensure that you do not have to reinvent the wheel. Technotronix provides PCB assembly and PCB fabrication service. Besides that, the cost and the turnaround time are also optimized so you will get a competitive advantage.

Top factors that can drive up PCB fabrication cost!

By | Date posted: | Last updated: January 16, 2023
PCB fabrication cost

When it comes to PCB fabrication, there are a wide variety of factors that affect its PCB fabrication cost. Right from the size of the PCB to its layer count, these factors have a strong bearing on the cost that you will incur in fabrication. A detailed understanding of these factors will help you fabricate a PCB that meets your requirements as well as your budgetary constraints.

Factors that impact PCB fabrication cost

1. Size of the PCB

Both the size as well as the shape of the PCB strongly influences its cost. Typically, the cost of the PCB increases with the increase in its surface area.

Commonly used dimensions include:

  • 18 X 24″ (457 x 610mm)
  • 18 X 21″ (457 x 533mm)
  • 21 X 24″ (533 x 610mm)

Additionally, the price is also affected by the space that is consumed by the components on the PCB.

2. Layer Count

As more layers are added to the PCB, its cost tends to go up. This stands to reason as additional layers means more material as also increased fabrication time. Additionally, it is important to remember that with a high number of layers the odds of developing defects also go up. The testing costs for high layer PCB therefore are also high. As a thumb rule, adding 4-6 layers increases the cost by around 30-40%.

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3. Complexity

The more complex your designs and configurations, the higher your cost. This is because complex boards come with additional processing steps, which involve the use of machines or manual labor.

4. Choice of Material

It is important that you choose PCB material that meets your requirements and fits your budget. This is because high-quality material for specialized board functions comes at an added cost. The choice of material, in turn, is influenced by several factors including but not limited to:

  • Thermal reliability
  • Heat Transfer
  • Signal Performance
  • Mechanical Properties, and more.

5. Trace and Space

Should you opt for tight traces, they come with challenges in etching and hence impact the price. On the other hand, enlarging the PCB trace width or adding solder mask to the traces also adds to the price of the PCB.

6. Hole Size

If the requirement is for small hole sizes, it stands to reason that it will require special tools or lasers for precision. In turn, this will impact the cost. Similarly, if the requirement is for a large number of holes, the cost tends to go up.

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7. Controlled Impedance

With controlled impedance, it is imperative that there be uniform trace width. In turn, there are several requirements, be it of a certain kind of material or specialized testing procedures, all of which impact the cost.

8. Tight Tolerances

Once again tight tolerances in the PCB design add to the complexity of the board and lead to testing and troubleshooting costs.

9. Copper Foil Weights

If thicker copper is to be used, there is a direct correlation with the cost. Additionally, there is also the requirement to use added pre-preg, all of which have cost implications.

10. Solder mask/ Silkscreen

The use of solder mask/silkscreen adds to the time taken in fabrication, not to mention the fact that it requires distinct processes that may require distinct tools.

11. Surface Finishes

The choice of surface finish has a strong implication on costs. There are standard finishes like OSP that are extremely cost-effective. However, finishes such as ENIG, for example, can significantly add to the cost.

12. Custom Specifications

Custom specifications can go a long way in increasing the cost of PCB. Some of the custom specifications include:

  • Contoured edges
  • Solder Mask Clearance
  • Side-plating, and more.

If there are details in your design that aren’t commonly assembled, it could lead to added time in production, not to mention the fact that it could need specialized tools. It is thus important to calculate the potential cost of your design in advance, for you to undertake a cost-benefit analysis.

To sum up

To keep costs at a reasonable level, it is important to look at several of the above-mentioned factors beforehand. This will ensure that you keep the costs in check.

Go with a Technotronix – a professional PCB fabricator with 4 decades of experience and ISO 9001:2015, ISO 13485:2016 certified who is equipped with the necessary industry best practices. So, you do not need to undertake unnecessary trial & error beyond a point. You can fill out the PCB fabrication quote form or mail us at sales@technotronix.us