The Importance of 20 Oz Copper Thickness in Heavy Copper PCB

For heavy copper printed circuit boards, the thickness of the copper in it plays a very important role. Now, the price depends on the number of oz copper thickness. This is why the 20 oz copper thickness will be more expensive compared to the 16 oz.

Usually, copper is used in fume hoods, countertops, upright jointed roofs, decorative roofs, downpipes, and gutters. Furthermore, it features hammering plates that have been pre-perforated.

The measurement of copper is done by weight is in ounces. When you expose copper to weather, it creates a bronze color. This appearance and color is affected by many factors. Copper may be black, green, brown, or somewhere in between. Many people believe that this change in color means corrosion. This is a wrong belief, because this color change is simply due to a chemical reaction. This doesn’t affect the product’s service life, rather copper extends it.

Let’s quickly go further into what 20 oz extreme PCB is all about.

What is a 20 oz Extreme PCB?

20 oz PCBs can simply be described as thick printed circuit boards having 20 oz copper thickness. This means that this printed circuit board has a huge thermal energy as well as large values of current.

To know the thickness of 20 oz PCB, we must have an idea of what 1 oz PCB is, and then multiply it by 20. 1 oz pcbs have a thickness of 1.37 mils or 0.00137 inch. Therefore, a 20 Oz metal core PCB will have a thickness of 20 multiplied by 1.37 mils which becomes 27.4 mils or 0.0274 inch.

Applications of the 20 oz Extreme PCB

The use of heavy copper in boards helps in solving the needs of high current and high power. There is an increase in this demand in the automobile industry, military, power energy, solar energy, computer, as well as other industries.

The 20 oz PCB will surely replace the old metal strips and traditional cable wiring. The transmission structure will not only improve efficiency in production, but it will reduce the costs of system maintenance and wiring.

Methods for Making 20 Oz PCB

Compared to the other ways of producing ordinary boards, producing the 20 oz PCB comes with some difficulties. These include the drilling processing, laminated structure, printing of solder mask, and etching accuracy. Presently, three methods are involved in the production of heavy copper.


Due to the thick copper foil scarcity in the market, the factory’s copper foil thickness is just 5oz. Other orders of thick copper foils that exceed this thickness are usually processed utilizing the 5oz copper foils, then the next stage is electroplating thickening.

Considering the overall cost for processing (too long plating time, very high capacity of producing electroplating equipment) and difficulty (the uniformity of etching, which is as a result of electroplating uniformity.


This has to do with laminating one of the layers of your very heavy copper foil. Though this method offers a better uniformity in copper thickness compared to the method for electroplating thickening, this still involves multiple etchings.


This method involves etching both the back and front sides of your copper foil. Before you go ahead to laminate, one of the copper foil’s sides is utilized in etching a pattern (half-depth). Next, this etched pattern is then pressed onto the board, and then processed in line with the usual process after lamination. After etching the second side, the copper thickness remaining is also etched through, as well as the substrate, leaving the first pattern pressed into the substrate.

Design Process of the 20 oz PCB

Before you go into designing your 20 oz PCB, it is very important to look into some parameters such as the spacing, ideal dimension, and parts type. Having this parameters with you, you will be able to do the below.

Always take note of the levels of copper fill in its inner layers. This is just to prevent fill levels that are very low. If a low resin level happens, there will be voids between the board’s layers. This will cause delamination.

It is advisable to choose the types and numbers of prepregs using software that will assist you in achieving multilayer designs.

Also important is the galvanic coating. The fact that you are working with 20 oz PCB, you will have to make use of more galvanic copper compared to other copper thicknesses.

Furthermore, makes sure that the layers of the solder resist come thick. By this, you will be able to guard your mosaic edges adequately. For instance, the end circumferential thickness has to have a minimum value of 0.25mm more than the initial thickness.

What Material Characteristics are Necessary for the 20 Oz PCBs Inner Layer?

Below are some of the characteristics of the material necessary for your 20 oz extreme PCB.

  • You must use a glass transition temperature that is high; this helps it to withstand any large thermal change.
  • This material must have a standard tensile strength
  • Take note of the shear strength of your material. This is important because the strength comes into play to tolerate shear force.
  • The materials utilized for the coreof the inner layer should possess close or matching coefficients of thermal expansions.
  • Identify the Dk (dielectric constant) of any material you use for the core of the inner layer.
  • This material must have a high voltage for dielectric breakdown.

20 oz Extreme PCB Manufacturer

There’s one thing about 20 oz PCB. This clearly shows its heavy copper and it requires special technology to ensure that the best results are achieves. This is why you should work with the best PCB manufacturer, because despite the issues with the fabrication of this thick copper board, top 20 0z extreme PCB manufacturers will still offer top-quality and affordable 20 oz copper thickness for your printed circuit boards.

This is why you should work with RayMing PCB. They have been doing this for years, and therefore they have the necessary experience to design the best PCB for you with respect to your specifications.


With this article, you should be convinced about the reliability of 20 oz copper PCB. It is advisable to work with the best PCB manufacturers to get the best results. You can contact us if you need more ideas regarding this.

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