The standard copper thickness for a circuit board is 1 oz copper PCB. This type of PCB features enough copper for the fabrication of a rigid PCB board. However, the application requirements will determine the amount of copper used in a PCB.
1 Oz PCB – What is it?
1 Oz PCB is a circuit board featuring 1 ounce copper. The copper weight of 1 oz PCB is about 1.37 mils or 34.79 microns. This PCB is widely used in the PCB industry. Most PCBs feature 1 oz copper thickness. In 1 oz PCB, 1 ounce of copper is flattened and evenly spread across one sq.f area.
1 oz PCB ensures maximum electricity passes at a specific temperature. This PCB offers great benefits such as high decomposition temperature and controlled resistance. 1 oz copper PCB comprises some effective materials such as an alloy of tin. This helps to maintain the thickness of copper PCB. Also, 1 oz copper PCB features flame retardant materials.
Some of the basic materials used for 1 oz copper PCB are epoxy resins and poly tetra fluorocarbon. Most PCBs feature 1 oz copper on every thin layer. Most manufacturers will use 1 oz finished copper weight on copper layers if a fab print isn’t included. The value of 1 Oz copper thickness in mm is 0.089mm.
The Maximum Current Carrying Capacity and Best Trace Width of 1 Oz PCB
Maximum current carrying capacity
One of the great features of 1 oz PCB is its maximum current carrying capacity. So, how do you know the maximum value? To get the maximum carrying capacity for this PCB, you need to make some calculations.
Therefore, Maximum current = 1 max
1 max= X (K X T rise)
b and c are constants.
b is 0.725
c is 0.44
The best trace width ensures the best performance. The required current determines the trace width. The trace width helps to connect signals between PCB junctions. The best value for the trace width of 1 oz copper PCB is between 7 to 12 mils.
You consider some factors before you choose the appropriate trace width for this type of PCB. Ensure you put the factors below into consideration;
- Trace termination
- Cross-sectional area
- Current capacity
You can determine the trace width value for 1 Oz PCB by making some calculations.
W= A/T x 1.378 mils
T represents trace thickness
T = 1.37 mils
A= Cross-sectional area (mils 2)
Copper Distribution in 1 oz PCB
Manufacturers need to distribute copper evenly throughout their PCB design. The distribution of copper across each layer is very important. Etching and plating are organic processes. This is because the manufacturer submerges the copper-clad laminate in chemicals. There isn’t an exact control over where to remove the copper or where to plate it.
The manufacturer masks off the intended image during etching. This helps to [protect the image from the etchant. However, chemicals dissolve the copper at various rates based on the location of the features on the panel. Etching helps to remove unnecessary material from the board.
If the finished copper weight of the top copper layer is 1 0z, the bottom layer should be 1 oz. If the copper weight for the top and bottom is different, etching will require more time. The copper distribution in 1 oz PCB must be equal.
How to Verify the Functionality of 1 Oz PCB
After fabricating 1 oz PCB, manufacturers need to test its functionality. There are different methods of testing 1 oz PCB’s functionality. These tests include:
Flying probe test
There are two probes in this test method. These probes help to evaluate the errors of ending points of the PCB. Here, you don’t need fixtures. This test is more reliable and faster. It is very effective in checking the defects of 1 oz PCB.
Solder float test
This test verifies how the PCB materials resist thermal stress. One of the factors that affect the functionality of 1 oz PCB is thermal resistance.
Automated optical inspection (AOI)
This is another method that helps in testing 1 oz PCB performance. AOI compares the 3D photos of 1 Oz PCB with the functional PCB. If the images are similar, then the PCB is functional
Solder pot test
Thermal vias errors result in solder wicking. A solder pot test helps you to check the solder joints of thermal vias.
Advantages of 1 oz PCB
This type of copper PCB offers great advantages.
Current carrying capacity
This copper PCB can optimize current carrying capacity. 1 oz PCB features high copper conductivity that enhances signal transmission. 1 oz copper plated device helps to transmit heat generated to a heat sink.
High power density
1 oz copper boards can offer high power density in devices. They manage the power in a circuit board.
This board has a high resistance to thermal stains. This means that 1 oz PCB can remain thermally stable in different thermal stress. Therefore, it offers excellent dimensional stability.
1 oz PCB provides functionality when used in electronic devices. This PCB can function via a wider range of temperatures. 1 oz copper PCB is compatible with high-performance electric circuits.
High decomposition temperature
1 oz copper PCB offers a high decomposition temperature value. This value is above 270°C. Therefore, it provides exceptional thermal resistivity.
Frequently Asked Questions
Can I use 1 Oz copper thickness in multilayer fabrication?
Yes, you can use 1 Oz copper thickness in fabricating multilayer PCB. You can use it on the external and internal layers of multilayer boards. You can use 0.5 Oz copper in the external layer and 1 oz copper in the internal layer foils.
Can I customize 1 OZ PCB?
1 oz PCB can be customized. However, it is important you have an appropriate schematic presentation of the PCB design. This will help to boost the capability of your circuit board.
1 Oz PCB is an ideal circuit board for several applications. This circuit board features a lot of benefits. 1 oz copper PCB is the best copper thickness. This is because you can use 1 oz copper thickness on the outer and inner layers of standard projects.