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!

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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.

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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

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What should be included in a PCB fabrication drawing?

By | Date posted: | Last updated: December 17, 2022
PCB Fabrication Drawing

A PCB fabrication drawing is an extremely important file that contains the manufacturing details of the circuit board. The more diligently the PCB fabrication drawing is created, the better the chances of the circuit board matching your exact requirements. A fabrication drawing lays down the specifics of the circuit board such as the board outline, layer stack-up, drill chart and more. A fabrication drawing along with an assembly drawing together, comes in extremely handy in assembling the circuit board.

How does a PCB Fabrication Drawing differ from Assembly Drawing?

As their names suggest, a fabrication drawing provides essential details that are required for the manufacturing of the board. An assembly drawing on the other hand lays down details about how every component will be attached to the board.

What should a PCB Fabrication Drawing Include?

Some of the aspects that a PCB Fabrication drawing must include:


It is important to mention the dimensions of the board as that will determine how much PCB material is required. Typically, the areas that need to be mentioned include:

  • Length of the board
  • Its width
  • Thickness
  • Outline
  • Tolerances

There also needs to be a Board Outline, which includes the cut-outs, holes, radii, specific distances from the origin, and more

Drill Chart

There needs to be a detailed drill chart that offers the following information:

  • Which layers need drilling
  • Drill Sizes
  • Tolerance, and more.

The drill chart has specific symbols to do with the hole size. It offers information on whether the holes are plated or not and more.

Layer Stack Up

The layer stack up has a lot of influence on some of the other aspects of the project. It is therefore imperative to convey information such as:

  • Material
  • Thickness
  • Copper Weight
  • Surface Finish
  • Tolerances
  • Controlled Impedance

Basis the Controlled Impedance requirement, the manufacturer can then look at aspects such as the dielectric constant, spacing, trace width and more.

Title Block

The Title block consists of information such as:

  • Customer Name
  • Part Numbers
  • Fabrication Number
  • Measurement Units, and more.

PCB Fabrication Notes

In addition, it will help to include PCB Fabrication Notes with the following information:

  • Requirements of Controlled Impedance
  • Manufacturing specifications
  • Raw material specifications
  • Plating details
  • Details of Solder Mask
  • Gold fingers, if present
  • Any specifications related to hole positions
  • Presence of via-in-pad, if any
  • Blind/Buried via, if any
  • Tolerances, both in terms of board tolerance & plating & etching tolerance

The PCB Fabrication drawing can be created in a wide variety of software, including but not limited to:

Eagle EDA
This is one of the commonly used software where the process is fairly simple. The basic steps involved here include generating the PCB Gerber File. Next you need to go to the Layout Editor. This will enable you to use the drill symbols on the board. With all the information about the number of layers & board material compiled, the files can be sent to the manufacturer.

The basic steps here include adding the Title Block. You need to add all the dimensions of the board in the outline. Next you can use the Graphics Tool to draw the stack up. Information such as board thickness, layer thickness, tolerances etc. can be mentioned. On the fabrication layer information such as number of layers, IPC class of the board, solder mask color, type of pads and more can be added.

Altium Designer
You need to use a blank drawing format and then add the details to it. Fab Notes & Drill charts can also be added. The files are automatically linked to the design database of the tool

To Sum up

The PCB fabrication drawings provide a lot of critical, additional information that is not available by way of Gerber Files. With all the above information mentioned, you can make sure that there are no communication gaps remaining & the board is manufactured to the exact details required. Needless to mention that other than providing detailed PCB fabrication drawings, the choice of experienced electronics contract manufacturer can go a long way in ensuring that you receive quality boards. An experienced manufacturer is equipped with industry best practices that ensure that you do not need to reinvent the wheel.

With advanced methods of PCB fabrication, we give you the finest PCB fabrication services. The PCB fab services from our experts will take it to the next level by accepting every type of latest technologies.

Request a quick PCB Fabrication quote!

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