How to apply thick copper circuit board trace resistance

The thickness of the PCB board has a huge influence on the designer during the design process of the PCB board. Consistency has an intrinsic gravity. If you ignore it, the PCB board may not work or may cause damage or sparks, which may also cause harm to components connected to the board. Since there are three types of PCB boards on the market: single-sided, double-sided, and multi-layer, the thickness of different PCB boards is also different.

PCB Trace Resistance Calculator – How to Calculate Trace Resistance?

Printed circuit boards all have a common basic operating formula. If any part of this formula is wrong, not even any trace resistors. A common mistake people make when testing PCB trace resistance is that they don’t know how to calculate it.

Printed Circuit Board Visualization
Before we can reveal and analyze this formula, we need to know what a conventional circuit board looks like, or at least on the surface. Most common circuit boards have a thin layer of copper. 009 mm and . 38 mm thickness. The most common PCB traces are 1 oz in weight or 0.03 mm in height.

PCB Trace Resistance Equation
Now that we know what a standard board looks like, we can give the formulas and put them together. The calculation method for any conductor is:

R = P x area. Each variable is assigned as follows:

R – Resistor.
P – resistivity of any given material.

Let’s use this formula to determine the resistance of pure copper, heated to 25°C.

The resistivity of pure copper at this particular temperature is 1.724. Knowing this, we need to multiply it by the area, which ranges from 6-10 ohms per centimeter.

Here’s another example: suppose we have a . 375mm area. If we multiply this by the resistivity we will get a resistance of 100 ohms which will yield 20 ohms per centimeter. This is a small value, but it may cause some variance, since the formula is not perfect. This is one thing that can affect the accuracy of PCB trace measurements.

Applying the PCB Trace Resistance Equation

Another example is resistor-based current sensing circuits in power systems. If the sense resistor is 1 ohm, and the same .025mm trace is used, the system will measure resistance at 1100 ohms instead of the preferred 1000 ohms. This is a big difference, and it can lead to a weaker currency than expected, or even weaker than necessary.

There are indeed methods of dealing with trace widths that do not involve complex calculations. These solutions save a lot of time and you should consider them before performing more complex calculations. Instead of calculating PCB trace width, you can consider these options to determine trace width.

The first method can be by visually observing the width, then increasing or decreasing the width to see what kind of circuit is properly connected to it. It does several things. First, it increases the copper area, giving you more room to experiment with different ohm levels. Second, it reduces the resistance on the copper plate. It also allows for more testing to determine the appropriate trace width.