What are heavy copper PCBs?

Printed circuit forums bring modern via etched copper tracks. The modern wearing potential of a copper hint may be advanced through growing its width, however this isn't constantly practical. Another manner to boom the modern wearing potential with out converting the width of the copper strains is to apply heavy or thick copper. This incorporates greater modern and complements performance with higher warmth management.

There aren't anyt any exact regulations that explain the quantity of copper for use while fabricating heavy copper forums. However, the PCB enterprise considers three or greater oz. of copper on any circuit board layer as heavy copper pcb board.

Design issues for thick-copper forums

Copper thickness and width

PCB designers gauge the quantity of modern required and primarily based totally in this they layout their heavy copper forums. This includes choosing the proper copper thickness, width, and the most temperature upward push the circuit board can withstand. The quantity of warmth a heavy copper board generates is proportional to the quantity of modern it incorporates.

How to pick the proper copper thickness

As said earlier, the copper thickness is decided through the modern passing via the conductor. The thickness of the board may be decided through a hint width calculator. It can calculate the 3 parameters that encompass hint width, modern potential, and temperature upward push. If any  parameters are known, the device calculates the third.

Current wearing potential

As modern passes via a copper hint its resistance inadvertently heats it up. The nearby warmth transition generates a strength that dissipates into the ecosystem through conduction and convection. The clothier ought to calculate the most modern the hint can bring earlier than it reaches the desirable temperature upward push of approximately 30°C. A thumb rule withinside the enterprise is that the internal layers can preserve simplest 50% of the modern-wearing potential of the uncovered strains.

Substrate cloth

Substrate of a PCB is every other thing a clothier ought to don't forget whilst designing heavy copper forums. Substrate substances variety from everyday FR-four cloth with operational temperatures of 130°C to superior substances with very excessive glass transition temperatures (Tg). The Tg of the copper and substrate cloth could be very important when you consider that a excessive modern might also additionally reason cracks and layer separation.

Coefficient of thermal growth (CTE)

Coefficient of thermal growth (CTE) is the charge of growth of a PCB cloth because it heats up. It is expressed in elements in keeping with million (ppm) improved for each diploma Celsius that it's far heated to. CTE among copper and the substrate cloth is likewise crucial as thermal strain produced through excessive currents via strains might also additionally bring about the formation of cracks, sooner or later inflicting board failure.

Circuit board floor thickness may be accelerated via electroplating. It reduces the resistance of copper strains via the development of warmth conduction. Electroplating is likewise utilized by fabricators for PTHs to decrease their thermal resistance. Resistance discount facilitates to burn up warmth efficaciously via the modes of warmth switch including conduction, convection, and radiation.