Heavy Copper PCB Fabrication Service

Standard PCBs are fabricated using standard copper etching and plating processes. Heavy copper PCBs have a similar construction, but dielectric separation is generally greater with heavier copper. Dielectric separation is the nonconductive substrate between the copper layers.

How much current can a heavy copper PCB carry? The answer depends on the amount of heat a printed circuit board can withstand. In order to determine the maximum current, you must first estimate the heat rise that’s connected to the applied current.

Heavy copper PCBs are essential for applications where a high current flow is required in the circuit. Without heavy copper traces or lamination, a standard PCB cannot bear the flow of heavy current. Whenever current flows through a circuit, the electronic components use electrical energy. There are a large number of heat losses that are commonly known as I2R losses. Common PCBs cannot take away the heat from the board as heavy copper PCBs do, so the components and the board will become overheated, and due to the failure of components, they stop working on the board.

Thus, a standard PCB cannot deal with the flow of heavy current. The Power Dissipated can be given as I2R. According to the relation, the magnitude of current highly affects the generated heat. Heat increases drastically, and it is visible from the square foot power of the current. We cannot reduce current because of the load, but we still have another factor, which is resistance. Heavy copper thicknesses traces have a low value of resistance compared to thin traces. The most important feature of heavy copper PCBs is that they can easily flow heavy currents through them and help in taking the heat away from the board. There can be heat sinks, and the traces transfer heat to them.

Many PCB manufacturers use different techniques for manufacturing heavy copper PCBs.

• Embedded heavy copper method

In this method of fabrication heavy copper PCB by using a flat surface. Here the heavy copper is added to the prepreg resins. The thickness of the resin determines the thickness of the copper. The fabricator positions the laminate into a plating tank for electroplating.

• Blue bar method

The blue bar method is done by adding thick copper bars into circuit boards. This method saves a large amount of material and reduces the weight of the PCB. During the process of fabrication, the resin flows into space within the copper traces, this helps to achieve an even top surface. Generally, all the fabricators pay attention to the level of copper fill between inner layers when it comes to multilayer boards with heavy copper layers. Low levels of fill and low levels of resin can lead to resin hunger.

Standard PCBs can also be produced with copper etching and plating processes. These PCBs are plated to add copper thickness to planes, traces, PTHs, and pads. The amount of copper used to produce standard PCBs is generally 1oz. For the production of heavy copper PCB, the amount of copper used is greater than 3oz. For standard circuit boards, copper etching and plating techniques are usually used.

However, heavy copper PCBs are produced by differential etching and step platting. Standard PCBs perform lighter activities, while heavy copper boards perform multiple heavy duties. Standard PCBs conduct a low current, while heavy copper PCBs conduct a higher current. Thick copper PCBs are ideal for high-end applications due to their efficient thermal distribution over the board. Heavy copper PCBs have better mechanical strength than standard PCBs. Heavy copper circuit boards enhance the board’s capability in which they are used.

Some other features that make thick copper PCBs different from all other PCBs:

• Copper weights:
  This is the main distinguishing feature of heavy copper-printed circuit boards. Copper weights are generally a concern to the weight of the copper used in a square foot area. This weight is measured in ounces. It shows the actual thickness of the copper layer.
• Outer layers:
  These are referred to as the finished copper layers of the board. Electronic components are placed in the external layers. The external layers begin with copper foil, also coated with copper plating. This helps to increase the thickness of the board. The copper weight of the external layers is selected in the initial stages for standard designs. Heavy copper PCB manufacturers can easily change the weight and thickness of the copper that suits customers’ requirements.
• Inner layers:
  For any standard project or product, the thickness of the dielectric and the mass of the copper are defined at the initial stages of designing. While the copper weight and thickness in these layers can be adjusted based on customers’ needs and requirements.

Many factors determine what thickness of PCB copper you choose. It would help if you considered the operating temperature, how long it would be exposed to heat, and any chance for a circuit board failure to avoid damage.

Copper is the most popular metal for a PCB because it transmits signals effectively and doesn’t lose electricity in the process.