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Thick Copper PCB

  • Thick Copper (Heavy Copper) up to 16oz
  • No minimum order requirement, High TG PCB prototyping order start from 1 pcs
  • 7/24 Live sales &tech support
  • 24 hours thick copper PCB prototype expedite services

What is the Width and Wire spaceing request for thick Copper PCB ?

Venture can produce the thick copper PCBs more than 16 oz. However, when the copper thickness more than 3 oz,we should should be paid to the width and wire spacing of the inner layer (line width/space), inner layer   outer layer

3oz: 8/10mil 8/12mil                           4oz: 8/12mil 9/13mil
5oz: 10/12mil 10/14mil                     6oz: 12/14mil 12/16mil
7oz : 14/16mil 14/18mil                    8oz :14/18mil 16/18mil
(1oz=35um or1.35 mil )

the Width and Wire spaceing request for thick Copper PCB
The more we should know about thick Copper PCB

The more we should know about thick Copper PCB ?

Industry Quality Standerds:
●ISO9001 Standerd        ●ISO14000 Standerd        ●UL Standerd

The shelt life of thick copper PCB: it can estimated at up 0.5 to 1 year with an thick copper PCB average thckiness rangeing from 0.12um to 0.4um

Elements affecting the shelf life of thick copper PCBs
●Airborne pollutants
●Types of Solder
●Method of welding

How to choose the best Thick copper PCB supplier In China ?

We should check as following

●Online Quote                                        ●Availability of design
●With Final Inspection report            ●Meet thick copper PCB standerd
●Short delivery time                             ●One by one solution for customer’s request

Venture can help you create heavy copper PCBs according to your needs.we have a strict quality management system that can ensure the high performance of your PCBs.All of the product with ISO, UL, and RoHS certified.

How to choose the best Thick copper PCB supplier In China

Your Best Thick (Heavy) Copper PCB Manufacturer in China

A Thick copper PCB( also named heavy copper PCB, thick copper printed circuit board) usually refers to a PCB with finished copper thickness≥ 3 oz per square foot in the inner and/or outer layers. So for example: when you have a PCB with 2oz copper per square foot thickness we will treat it as standard copper thickness, but if your PCB is 4oz per square foot copper thickness we will we will call it is a thick copper PCB(heavy copper PCB).

Thick Copper PCB 5

Thick Copper PCB For Automotive

When electrical engineer design the thick copper PCB, what they most concern is the width and thickness of the heavy copper since this will determine how big current-carrying capacity the PCB can be. So besides the high current-carrying capacity, what else benefits does thick copper PCB have:

  • Thick copper PCBs can eliminate the wired bus configurations
  • Thick copper PCBs allow selective areas plated with Heavy copper, this can be used as a heat sink
  • Thick copper PCBs are able to resist higher temperatures for longer times and provide stronger connection points


Thick Copper PCB 7 2 Layers, 6 Oz thick (heavy) copper PCB for automotive

Thick Copper PCB (Heavy Copper PCB) Capabilities:


Thick Copper PCB Feature


Layers Counts1-32 layers
MaterialsFR-4 (All Tg Ranges), Teflon, Ceramic, Metal Core
Finished Thickness.020″ – .275″
Solder mask colorGreen, Blue, Red, Black, Clear & White Solder Masks & Legend Inks
Minimum solder mask Clearance6 mil
Minimum solder Dam Width5.5 mil
Maximum Copper weights (finished)16oz
Minimum drilling bit hole size .012″
Maximum Hole Aspect Ratio30:1
Controlled impedance± 10%
Surface finishes availableHASL( Hot Air Solder Leveling), Immersion gold( ENIG), Immersion silver


If you’re not sure whether your products require thick copper PCB (heavy copper PCB) or how thickness the copper it goes, or how a thick copper printed circuit board can do to protect your sensitive circuits, we’re more than happy to share everything we know from our 10 years experiences. we are trusted by thousands of electronic engineers all around the world through our100% quality guaranteed policy. With our 2 hours rapid response services from our 24/7 sales and tech support team and excellent after-sales service, we will be your best thick copper( heavy copper)PCB supplier in China. At Venture we can answer any thick copper PCB questions that you may have, pls feel free to contact us anytime.

Your Leading Thick Copper PCB Supplier in China

Venture has more than 10 years experiences producing thick copper PCBs, from single side PCB to multilayer PCBs, our thick copper( heavy copper) PCB have been widely used in, automotive, computer, industrial controls and military applications, such as

  • High power rectifiers
  • Power converters
  • UPS systems
  • Protection relays
  • Welding equipment
  • Radar systems

Thick Copper PCB 6

Thick Copper PCB: 4 Layers, ENIG, 8Oz Thick Copper for Industrial Application

High current applications can bring challenges to PCB manufacturers because the loads they need to manage concerns safety, the solder mask process must be strictly controlled since the heavy copper thickness is much thicker than the substrate,it can cause issues during solder mask process, meanwhile pattern etching process, lamination and drilling process are all needed to be strictly controlled during thick copper PCB manufacturing. Venture’s10 years thick copper PCB experiences can make sure the whole processes are been handled correctly.

Thick Copper PCB: The Ultimate Guide

Thick Copper PCB

Do you want to venture or buy thick copper PCBs?

Today’s guide highlights critical aspects you need to know about thick copper printed circuit boards.

It covers basic to advanced concepts, from definition, applications, design process, fabrication, standards and many more.

By the end of it all, you should be to choose a suitable thick copper PCB for your applications.

Let’s get started…

What is Thick Copper PCB?

First, let me put this straight:

Thick copper PCB is also known as heavy copper PCB.

Now, back to our subject…

A thick copper PCB refers to printed circuit board with 3 ounces copper thickness per square foot in its outer and/or inner layers.

This is what I am talking about:

Thick copper PCB

Thick copper PCB

Also, this term is additionally applied to circuits with copper thickness with more than 4 oz/ft2.

Of course, it is the same scenario when it comes to printed circuit boards with 20 oz/ ft2 to 200 oz/ ft2 of copper on the external and internal layers.

Of course, during the manufacturing process, it is important to combine copper material with an appropriate substrate.

This way, you will get a dependable platform for wiring.

Obviously, your manufacturer will choose an appropriate etching and plating techniques.

And of course, the aim here is to introduce copper thickness through sidewalls and plated holes.

Why Use Thick Copper PCB

Unlike other types of printed circuit boards, thick copper PCB has unique features. It is for this reason that it is common in some specialized applications.

You will learn more about applications of thick copper PCB later in this guide.

For now, let’s quickly go through some of the main reasons why you should use thick copper PCB:

Thick copper PCB

Thick copper PCB

1.Heavy copper PCB conduct higher current

Heavy copper PCBs are used in the electrical industry to help in conducting high currents.

They are used to link different boards together to ensure currents cannot be cut premature.

It has the best current carrying ability and capacity.

2.Better thermal distribution

Its copper-plated vias offer experts with high thermal resistance to work with.

Reliable performance and ideal thermal management is the actual driver behind high demand levels for copper PCBs.

Besides, you can count on thick copper PCB even in harsh environment. Take for instance, when there is high temperature fluctuations.

For example, at high ambient temperature, the mechanical resistance of contract points and PTH is increase as well.

3.Ease to implement in complex switches even within a small space

Thick copper PCB have eliminated the bulky and complex wires or metal bars. This produces an electrical unit that is simple and lightweight.

4.Good mechanical strength

Ideally, thick copper printed circuit boards have good mechanical strength. This makes the whole electrical system robust and durable.

5.Best for large components with high power loss since they help dissipate heat

Overheating of electrical system is dangerous. In fact, your systems can fail any time.

This where thick copper PCB plays an integral role.

With thick copper PCB, you will easily avoid possible overheating. Thus, you can easily maintain the overall temperature to desired levels.

Basically, thick copper printed circuit board will effectively dissipate excess heat. Thereby, ensuring your circuits perform optimally.

6.Can support exotic material without possible component failure

At times, the design of your electronic component may require the use of exotic material.

Therefore, to enhance and protect such materials you need a thick copper PCB.

7.On-board heat sinks for better performance

Do you know thick copper printed circuit board provides an onboard heat sink?

You can easily achieve effective and reliable heat sinks on mosaic surfaces.

This is an important aspect in electrical and electronic components.

Remember, heat is transferred between layers through collections of vias.

The good thing about this method is that it reduces assembly time and cost.

Clearly, you can see there are many reasons why you should use thick copper printed circuit boards.

But, even before you opt for thick copper circuit boards, understand the requirements of your applications.

Heavy Copper PCB Design Process

With the need for better thermal management systems, thick copper PCB create a lasting wiring solutions.

They conduct electricity optimally and dissipate excess heat that can damage the system.

As a result, you don’t have to worry about possible thermal stress.

Besides, the heavy copper PCB are made on small footprints, with different copper weights.

Heavy copper PCB

Heavy copper PCB

To effectively achieve everything highlighted above, your main focus should be on the design.

Therefore, you must consider the manufacturing and quality verification process.

Remember, the capacities of processes define the design rule check parameters.

This in turn defines:

  • Minimum allowed dimensions
  • Spacing
  • Type of components, etc.

Table 1: This shows the design rule check dimensions for PCB manufacturers, TS PCB.


ParameterCopper foil baseline thickness
105 µm140 µm175 µm210 µm
Min spacing [mils]13152027
Min. path width [mils]12141825
Loss [mils / mm]ca. 3 / 0.08ca. 5 / 0.13ca. 6 / 0.15ca. 7 / 0.18

DRC parameters vs. copper foil thickness

Now, let’s look at some unique design scenarios:

1)When you decide to design multiplayer printed circuit boards with a thick conductor layer, you need to pay more  attention to its copper fill levels between inner layers.

If the fill levels are too low at low resin levels, ‘resin hunger’ effects arise and voids show up between printed circuit board layers.

This leads to delamination.

2)Delamination, however, can be prevented when copper fill levels are at least 75% for 105 μm or thicker inner layers.

While, the distribution of copper needs to be an intact as it can be.

It is advised to choose the types and number of prepregs with software that aids in having multilayer build-up designs aided.

3)Also, it is important to know that the galvanic coating of printed circuit boards that mark conductor layers in excess of 105μm thick necessitate 40 μm to 50 μm deposition.

This is mostly more galvanic copper compared to printed circuit boards that have thinner layers of copper.

These thinner types mostly feature 25 μm per galvanic copper layers. These layers enhance the mechanical strength of metalized holes or PTH.

However, it can also lessen all finished diameters of specific vias by over 0.1 mm.

As a general supposition for thin copper printed circuit boards.

Remember, it is a mean metallization thickness within the metalized hole walls.

This is added to the diameter values of holes designed to determine drill bit diameter values.

4)Applying thick copper layers results in an increase in PCB thickness. Remember, solder resist layers should be thick to protect mosaic edges effectively.

Therefore, the completed circumferential thickness is at least 0.25 mm high than its original thickness.

Once you know all these rules, you can go ahead and start your PCB design and layout process.

Well, this is a detailed process.

The best part?

I already have a comprehensive guide on this – Look at this: PCB Designs & Layout Guide.

PCB design and layout

PCB design and layout

How to Fabricate Thick Copper PCB

Mostly, you can use either etching or plating methods to fabricate thick copper PCB.

Here, the main goal is to include copper thickness to via plated holes and sidewalls.

Remember, plated holes can weaken when the PCB is subjected to many cycles during the production process.

Ideally, when you add heavy copper, the holes will strengthen.

This makes the PCBs a perfect choice for high power and current applications, more so in electrical circuits.

Thick copper printed circuit board

Thick copper printed circuit board

Generally, when it comes to thick copper PCBs with over 105 μm, you may experience certain challenges during the fabrication process.

It is common with solder masks.

Because of the limitation due to thickness of ink on substrate. The electrostatic spraying or spraying method cannot be utilized.

Currently, the two major methods in the industry can use just traditional screen prints.

One is to have multiple solder masks printed.

The other is to ensure substrate is made initially, and then filled with solder masks.

Then, used as normal printed circuit board normal solder resists.

Nonetheless, printing screens will lead to issues with quality like broken soldering bridges, solder welding holes, and air bubbles in lines.

Below is the fabrication process or method

The method of having thick mosaic etching includes an effect known as ‘undercutting’. This is where the circuit path width is lessened.

The effect is shown in below figures. These represent a cross-section of laminates before (Fig. 6) and after etching in fig. 7.

The components that are marked ‘resist’ in these figures are protective layers which are photopolymer in single sided printed circuit boards or tin.

These are mostly fitted at the end of galvanic coating methods, on double and multilayer printed circuit boards.

Undercutting always lessens the cross-section of printed circuit board paths from a square to a trapezoid-like type.

Thick Copper PCB Assembly Process

Well, the process of thick copper PCB assembly is simple and straight forward.

Here is how to go about it:

  • The process begins with a solid sheet of copper. So, the copper foil.
  • Then it is pre-laminated onto a fiberglass sheet to ensure it has a thickness that is uniform.
  • The PCB is then drilled.
  • Copper plating method starts. This is done to plate the inside of drilled holes. At times, drilling is handled before etching and other times after.
  • It depends more on the number of layers and the lamination sequence you seek to achieve. At times, plating is done or handled before etching.
  • However, if plating is done before etching, then a lot of copper that was just plated on can be detached again.
  • Plating is completed selectively. This means it bonds only to specific traces or areas of printed circuit board.
  • Also, this is done by applying masks to have plating material resist. This can be done with either nickel, copper, gold, or other metals.

Heavy copper PCBs might have many thick copper layers plated up.

Thick copper PCB

Thick copper PCB

There are some of these boards that are made out of 100% solid metal inner core. This can be copper too.

Standard PCB vs. Thick Copper PCB – An Ultimate Comparison

Standard printed circuit boards, whether they are multilayered or double-sided, can be manufactured with copper etching and plating process combinations.

Circuit layers mostly begin as thin copper foil sheets. They are etched to get rid of unwanted copper.

Thick copper printed circuit board

Standard PCB

They are also plated to include copper thickness to traces, planes, pads, and plated through homes.

All circuit layers are laminated to have a total package with the use of epoxy-based substrate like FR4 or polyimide.

Heavy copper circuits are made in the exact the same.

However, they are made with etching and plating methods. These methods include high speed or step plating and differential etching.

Historically, this copper type features were made entirely through etching thick copper-clad.

This was mostly laminated board material which caused rough trace sidewalls and intolerable undercutting.

With advancement in the technology of plating, heavy copper now features are made with plating and etching combined.

This leads to even sidewalls and insignificant undercuts.

Having heavy copper plating done helps board fabricators to have high copper thickness amounts in plated holes as well as via sidewalls.

In general, high powered circuits and control circuits were made on different boards.

Using heavy copper plating has made it possible to include high-current circuits to have simple board structures comprehended.

Thick copper printed circuit board

Thick copper printed circuit board

Heavy copper features are ideal in its way. This is because it can be linked seamlessly to a standard circuit board.

These standard and heavy PCBs can be easily placed without limitations offered by the designer.

Main Heavy Copper PCB Specification to Consider

PCB layers

PCB layers

  • Width of Thick Copper PCB
  • Copper Thickness on PCB – 1 ounce minimum depending on thickness layers.
  • Current Carrying Capacity of Thick Copper PCB – The current carrying capacity of thick copper PCB always differs.
  • Depending on what your needs are the currents and thickness copper level cannot be the same. So, always make sure you have that known.
  • Copper Thickness Tolerance – Not all methods of making or manufacturing thick copper PCB requires specific methods.
  • The best manufacturers will make sure that is done to prevent issues with your printed circuit board in the end.
  • Heavy copper PCB quality standards – Always choose the right companies that follow the right manufacturing standards.
  • When quality standards are followed, you benefit highly from the PCB you get.
  • Thick Copper PCB Layers – Heavy copper printed circuit boards can be made with copper weights anywhere from 4oz/ft 2 to 20oz/ft 2
  • Heavy copper PCB material – copper foil or other metals depending on what it is needed for.
  • Minimum tracing – Most of the commercial thick copper printed board circuits are made for low-voltage or low-power usage.
  • They are used with copper traces or planes made up of copper weights ranging from 1/2oz/ft 2 to 3oz/ft 2.  So, mostly, the minimum stands at 1/2oz/ft 2.
  • Heavy copper PCB surface finish – Finishes for internet and external heavy copper PCBs surface always differ.
  • So, it always boils down to what you need the board for and what must be done on the board.

Applications of Thick Copper PCB

Heavy copper is not an innovation that is new.

It has been used for so many years in making weapon control systems in the military and defense applications.

Most mainstream electronics manufacturers require different ways to have heat transferred away from devices.

Computer motherboard

Computer motherboard

This is what makes the use of heavy copper PCBs higher.

There are so many ways thick copper PCBs can be applied or used. However, make sure nothing is taken for granted.

Just find a way to ensure nothing is taken for granted. Below are some of the ways they are applied or used:

  • Military Applications like storage pumping plants.
  • Automotive Industry like rail traction systems and safety and signal systems.
  • Planar transformer – One use of thick copper PCBs with thick mosaic layers are tiny planar transformers.
  • They have become very famous in pulse converters. Unlike normal transformers, its windings are made over PCB plans as paths in coil shapes.
  • These windings are arranged around cuts, into parts of ferrite core enter, and bound with spring clamps or adhesives.
  • This solution helps manufacturing of very small transformers with low winding leak inductance.

a)Solar Panels like solar power converters.

b)Amplification systems

c)High Current Circuits

d)High Heat Dissipation

e)Power Control Systems like power line monitors.

f)Power Distribution like torque controls.

g)Electric Power Systems like protection and overhead relays.

h)Cooling High Power Systems like HVAC systems. Also, planar arrangements of windings also favor transformer


It also reduces its Kelvin effect which lessens the power effectiveness of transformers.

i)Telecommunications Industry like UPS systems.

Detailed explanations below to know:

Printed circuit boards with thick mosaic layers, its look is shown below. It can be single, double, or multilayer.

These PCBs in the beginning were used and is still in use in military and aerospace industries. In these industries, they serve mainly in the supply of power, distribution, and management systems.

Heavy copper PCB with thick layer

Heavy copper PCB with thick layer

PCBs with thick layers of copper foil

PCBs with thick layers of copper foil

Currently, thick mosaic layered printed circuit boards have found its use in most industrial sectors such as:

  • Solar energy
  • Welding equipment
  • Solar energy panels
  • Different power adapters/supply units
  • High powered converters
  • Power engineering systems
  • Automotive and railway industries.

Thick copper foil printed circuit boards boast of many advantages. For instance, copper is an amazing thermal and electrical conductor.

Due to that it enhances the transfer of heat along and across the printed circuit board.

This lessens damaging stress as a result of uneven heating of printed circuit boards.

The level of stress might lead in micro-fracturing of mosaics. This may lead to irregular or lasting open circuits.

It ultimately leads to the failure of the device that has been affected.

Mosaic heat transfer and dissipation

Mosaic heat transfer and dissipation

Now, before wrapping up this discussion, here are a few things that you need to know:

1)How thick is the copper thickness on a printed circuit board in ounces?

This is the resulting thickness level when 1 ounce of copper is completely pressed and spread consistently over one square foot area.

2)How is thickness multiplied?

You just need to have the thickness multiplied by 1 ounce.

3)Does the thickness of copper affect its cost?

Yes, indeed.

The thicker the copper used for the circuit board, the costlier it becomes. Thicker copper weight takes a lot of time and is quite tricky too.

All of these add to the cost. However, you can find some manufacturers ready to be reasonable.

4)Do manufacturers of thick copper PCBs require specifications and why?

Definitely, they do.

If you do not send them specifications after them asking, most manufacturers assume.


They assume that you want a standard type of heavy copper PCB. So they have that made for you.

5)Does more current require thicker copper?


Thicker copper is needed if you want a PCB with higher current as well as traces width.


Not all the time that you will find the best manufacturers of heavy copper PCBs.

Remember, it is important that you know what you are getting. Never make payment for a service that you never benefit from.

And, as you can see from this guide, it outline everything you need to know about thick copper PCB.

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