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Heavy Copper PCB

Jarnistech > Heavy Copper PCB
Heavy Copper PCB

What Is the Heavy Copper PCB?

Heavy copper circuit board is one of the types of a printed circuit board, and its copper with a thickness of ≥3 OZ per square in its outer and inner layers, since its thicker plating, so we call it heavy copper PCB. In the manufacturing of a the PCBs made of heavy copper the copper thickness is increased through the plated holes and sidewalls.

For instance, if an PCB is made of 2OZ of copper per square, it’s a regular PCB. If it’s more than 3oz copper, it’s a Heavy copper PCB. The PCB with heavy copper is considered as a solid wiring choice. It is distinct from PCB made of extreme copper, which has 20 up to 200 oz for every sq. ft.

The additional copper thickness allows this board to carry higher current. The PCB made of heavy copper has strong mechanical power in the plated-through-holes and connectors. This kind of PCB may also referred to as PCB made of thick copper.

Send your PCB file today to get a quote from JarnisTech. We support a 20 OZ inner layer, 30 OZ outer layer for extreme copper PCB manufacture.

Heavy Copper PCB Manufactured

Etching or plating is often employed in the manufacture of extreme copper PCB. The main objective is to increase the thickness of copper on sidewalls as well as plated holes. But, a normal etching process can cause unevenly etched margins and edges. Thus, the additional thickness of copper requires special etching and plating processes when manufacturing heavy copper PCBs.

As part of the manufacturing process, heavy copper circuit boards are electroplated throughout the PCB manufacturing process. On the PCB, this will assist thicken the PTH barrier. This means that the number of layers is reduced and the distribution of impedance gets decreased by this technique. But, if PCBs are subjected to multiple cycles during the process of manufacturing The holes that are plated become damaged.

Are You Looking for an Heavy Copper PCB Quote?

We follow a well-organized procedure and the best software to provide you with a quote within 24 hours. Once you have PCB Gerber files along with any fabrication drawings or diagrams, then send them to us. Finally, our engineers will examine the information and send us an extensive document so that we can have a better review of your copper-heavy PCB project.

3OZ Copper Thickness PCB Board

Heavy Copper PCB Production

When compared to the production of normal boards, the process for thick copper foil circuit boards presents a number of challenges. The accuracy of etching, laminated structure, drill process and the soldering mask process all come with particular challenges.

At present, heavy copper PCBs are made using three primary methods:


Factory standing copper foil is generally only 5OZ thick because thick copper foil is hard to find in the market. In some cases, thick copper foil orders exceeding the thickness are processed using 5OZ copper foil and then thickened by electroplating. In consideration of the overall cost of processing (plating duration too long, the capability of electroplating equipment too high) and the difficulty (etching uniformity that is caused by the uniformity of electroplating). In general, the thickness of heavy copper used in electroplating is restricted to less than 3OZ. the actual thickness of copper is lower than 8OZ.


As this method requires multiple etchings to thicken a layer of ultra-heavy copper foil, it may yield better copper thickness uniformity than electroplating thickening. But the bottom etching of this line width leaves a large residue at the bottom, making the solder mask printing difficult. Wiring density very limited.

Heavy Copper Foil Lamination and Etching

This method is achieved by etching both the back and front side of the foil.  Prior to lamination, one side of the copper foil can be used to etch the pattern of half-depth, then the etched pattern is then pressed in the substrate, and then processed in the standard procedure following lamination. Once the second layer is etched, the remainder of the of the copper is then etched the substrate. Then, the portion of the substrate is etched, and then the first pattern is then pressed into the substrate.

The benefit is that the thickness of copper of the two etchings are diminished, which can be beneficial to the control of line width. Additionally, the copper thickness visible outside of the substrate is also decreased as well as the complexity of printing a solder mask additionally enhanced. The most difficult part is the alignment of two pattern etchings as well as in the computation of PP filling amount to press. Our company’s copper foil thick circuit boards with a thickness of 6OZ typically use this method.

Embedded Copper Method: This method creates PCBs made of heavy copper with flat surfaces. The heavy copper is placed inside the prepreg resin. The size of this resin determines how thick the copper is.

As an example, the manufacturer starts with the 6–mil laminate and a 1 0z copper clad. The copper clad is coated by a photoresist. Then, a 5-mil laser beam is utilized in cutting the circuit pattern from the side of the laminate. The laser needs to through the laminate to cut copper foil. If the machine is controlled, it will be able to keep any copper foil from getting damaged.

The fabricator places the laminate inside the tank for plating to be electroplated. The copper plating results in approximately 6 mils of plating thickness after the laser-cut groove is filled on the laminate.

Blue Bar Method: The blue bar method is the process of inserting thick copper wires into circuit boards. This method reduces the overall circuit board weight while saving material. In this process, the resin flows into the spaces between the copper traces, forming in an even top surface. This allows for an even top layer. Fabricators must be aware of the amount of copper fill between the two layers when they are making multilayer board that has heavy copper layers. Insufficient fill levels and the absence of resin may result in resin hunger.

Why Is It Difficult To Produce Heavy Copper PCB?

Thick Copper PCB

Copper Foil

Typically, heavy copper plates have higher voltage resistance requirements, which means that it is essential that the roughness (Rz) of the copper foil needs to be low and uniform since this is the determining factor in deciding if the thin core board (under 125μm) are suitable for high-quality copper circuit boards, or Can it achieve a lower finished thickness of the printed board.


Due to the thick copper foil, heavy copper foil printed circuit boards are prone to problems such as insufficient filling, excessive glue flow, uneven thickness, and voids. For pressing, choose PP (1080 or 106) that contains a large amount of glue, and choose the number of PP sheets according to the actual filling requirements to avoid an excessive amount of filling resulting in a pressing slide.


As a result of the high copper content of the heavy copper printed circuit board when drilling, especially when drilling multilayer heavy copper, the drill bit heats up rapidly when the drill is rotated, and it is easy to cut the drill edge if the copper wire undercutting occurs. Damage, resulting in the roughness of the hole wall and the nail head being too large, causing the via failure during welding.

Thus, choosing the appropriate drill bit and the right parameters is crucial to the process. Additionally, the minimum aperture during the design process should be higher than 0.4mm as much as possible. The thicker the copper, the greater it is the number of layers and the greater opening, the more suited to manufacturing and processing. Our company offers separate drilling specifications for copper foil circuit boards, which maintain the smoothness of the hole’s wall and provide a high-quality hole.


In the process of etching, the etching solution can be able to attack the sides of the line, which causes side corrosion, which makes the actual line width smaller than the design line width. The more copper is thick, the more time the etching process will be. Side corrosion will also be more severe. In order to offset the effects of side corrosion it is necessary that the PCB Production Draft will compensate for the line width. However, line width compensation reduces the line spacing, and also increases the time for etching, and due to various copper thicknesses, are required to design the line width and line spacing.

JarnisTech Provide High Quality Heavy Copper PCB

When it comes to PCB fabrication heavy copper PCB requires special technology , which makes the process difficult. It also has certain technical requirements, as such, heavy copper PCBs are more expensive to make as compared to other circuit boards. Even though the cost is not affordable, the service and quality will be the most effective.

As a leader in the PCB industry with more than 20 years of experience, JarnisTech has become a leading manufacturer of PCBs and turnkey PCB assembly in China. Not only are we highly skilled in fast-turn prototypes and PCB assemblies, but also in small and medium volume PCB fabrication, our primary focus is to ensure client satisfaction. we’ll do to create your board to the highest quality to meet your expectations and committed to observing the highest standards for PCB assembly and fabrication.

Capabilities Of Copper Heavy PCB Manufacturer

The heavy copper printed circuit boards have 3 ounces copper in their outer and inner layers. They are extremely sought-after because of their ability to manage heat. The high copper content assists in keeping the internal components cool, and boosts their performance. In order to ensure efficient thermal management and power distribution, JarnisTech provides performance-oriented, heavy copper PCBs.

Copper Thickness 4OZ PCB

Our capabilities in the following areas have helped us grow into one of the most reputable copper-rich printed circuit boards producers in China:

Base MaterialFR/4 all TGs, Aluminum, Ceramic, Rogers,Teflon, Polyamide, Copper etc.
Copper Thickness4 Oz – 10 Oz
Extreme Heavy Copper20 Oz – 200 Oz
SoldermaskYellow/Red Oil/Green/Blue/Black/White
Surface FinishingImmersion Gold(ENIG), OSP, and HASL
OutlinePunching, Routing, V-Cut
Maximum Number of Layers60
Finished Thickness0.020 ʺ – .275 ʺ
Minimum Soldermask Clearance5 MIL
Minimum Solder Dam Width5 MIL
ViasBlind and Buried Vias

Minimum Drill Bit Hole Size: .012ʺ

Minimum Holes Size: .008″ +.005″/-.008″

Maximum Hole Aspect Ratio = 12:1

Controlled Impedance+/- 5%
Minimum Silkscreen Line Width


How Selecting the Right Heavy Copper PCB Manufacturers?

If you’re looking for heavy copper PCB producers There are some things to consider:

● Price.
● On-time Delivery.
● Industry Know-how and Skills.
● Product Quality and Certifications.

Advantages of Heavy Copper PCB

● High thermal tolerability capacity.
● Outstanding current capacity for carrying capacity.
● Eliminates the complicated cabled bus setup.
● Combination of several copper weights on one PCB by condensing the circuit size.
● Usage can be improved by using high-temperature materials to ensure less chance of failure in the circuit.
● Due to the enhancement of the mechanical properties due to the improvement of mechanical properties, tropical materials are utilized to make PCB.
● Heavy copper deposition in particular areas may be connected via the Cold Plate Interfaces in order to serve as heat sinks.
● Product dimensions remain compact for multiple copper weights on similar circuit layers.
● Incorporated multiple copper weights are connected to the same circuitry.
● Transforms on-board high-power density.
● Heavy copper-plated vias go through the current that is elevated for the PCB.
● Assists heat transfer to the sink’s outer surface.
● Integrates high-current circuits to control circuits on a single PCB.
● Selective areas are plated with heavy copper , which serves as in the heat sinks built-in and cold sinks.

PCB Manufacturing Cost and Weight of Copper

If your PCB’s design calls for heavy copper, be aware that manufacturing costs and time will be affected. Naturally, the thicker copper is more costly than regular copper. Additionally, thicker copper demands greater time and resources for manufacturing and, as a result, increases the cost of manufacturing.

The Disadvantage of Heavy Copper PCB

● In the process of etching, increase in cost.
● Fabrication The cost of PCBs made of heavy copper is very high.
● Heavy Copper PCBs are heavier than other printed circuit boards, resulting in a higher cost of shipping.
● The process of etching needs an enormous quantity of copper that must be removed.
● It is difficult to create thinner lines and copper lines and thick copper.
● Heavy copper lines make the surface uneven.

What Is the Difference Between Ordinary PCB and Thick Copper PCB?

Standard PCBs can be made using copper and etching as well as plating. These PCBs are then plated to increase the thickness of copper on planes and traces, as well as PTHs and pads. The copper content utilized in the manufacture of regular PCBs is 1oz. In the manufacture of heavy copper PCBs, the quantity utilized of copper is higher than 3oz.

For standard circuit boards, it is common to use copper etching and plating techniques. However, the heavier copper PCBs are created by the process of differential etching and step plating. Standard PCBs are used for lighter tasks while the heavy copper boards are able to perform more demanding duties.

Compared to standard PCBs , heavy copper PCBs conduct higher current. PCBs made of thick copper are great for high-end applications because of their effective thermal distribution. They have greater mechanical durability than regular PCBs. The use of copper circuit boards with heavy copper increases the capabilities of the boards that they are used in.

Features of Thick Copper PCBs Different From Other PCBs

2 Layer Heavy Copper PCB

Copper Weight

It is the primary distinguishing factor of copper PCBs with heavy weight. A copper weight refers to the amount of copper used in a square foot area.In general, it indicates the thickness of the copper layer on the sheet. The weight is typically expressed in ounces(oz).

Outside Layers

These refer to the external copper layers of the board. electronic components are generally attached to the outer layers. Copper foil forms the outer layer, which is then coated with copper. This increases the thickness. Copper weight for layers outside is predetermined for typical designs. Heavy Copper PCB makers can adjust the thickness and weight of the copper to meet your requirements.

Inner Layers

They are the dielectric thickness as well as the copper mass of internal layers are set for the standard designs. However, the thickness and weight of copper within these layers are altered based on your requirements.

Thick Copper PCBs Applications

As a preeminent fabricator with a specialization in thick copper PCBs, we possess the competence to meet the dynamic needs of our diverse client base spanning sectors such as military, defense, power generation, nuclear, automotive, and beyond.  Our expertise in the production of heavy copper PCBs empowers us to serve a range of challenging applications.  here are heavy copper pcb application:

● Power amplifier modules
● DC-to-DC power converters
● Planar transformers
● Heat dissipation products
● Automotive junction boxes for power distribution
● High Power distribution board
● Weapons control systems
● Power sources in radar systems
● Power distribution panels
● Battery charging and monitoring system
● Central power system
● Power electronic devices

With a rich legacy of talent that is world-class and new technologies, we are able to transform even the most complicated designs into high-performance thick copper boards in a short time frames. Our offered printed circuit boards comply with all regulatory standards will bring you expected high-end performance. If you have any queries about our PCBs made of thick copper capabilities, talk to one of our experts at JarnisTech as soon as possible. Free PCB quotations are only send PCB Gerber files to [email protected].


The fabrication of heavy copper PCBs demands considered management as any erroneous handling can adversely impinge on performance. It’s crucial to partner with seasoned manufacturers to secure optimal results.

Recognized as a respectable PCB manufacturer, JarnisTech puts forth a vast assortment of PCB solutions customized to diverse applications. With over two decades of hands-on experience since our inception in 2000, JarnisTech has cultivated a reputation for delivering superior quality heavy copper PCBs.

For all your heavy copper PCB development needs, JarnisTech positions itself as your all-inclusive solution provider, offering proficiency and reliability to meet your stringent requirements.

Call us to get a free quote now