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Navigating the Key Differences Between 1 oz vs 2 oz Copper in PCB Design

Tue March 12, 2024

1 oz vs 2 oz Copper PCB

Selecting the optimal copper weight is a crucial decision in PCB design. Copper weight, typically measured in ounces per square foot (oz), directly impacts performance, current capacity, and thermal properties. Here, we will main compare 1 oz vs 2 oz copper PCBs, exploring the implications of each.

What is a 1 oz Copper PCB?

A 1 oz PCB features 1 ounce copper with a thickness of 1.37 mils or 34.79 microns. This is a standard copper weight for rigid PCBs, ensuring efficient conduction while maintaining resistance. 1 oz copper PCBs utilize tin alloys to maintain the desired 1 oz thickness. They also employ flame retardant materials for safety and reliability.

1 oz copper PCBs typically use epoxy resins and PTFE. The 1 oz copper layer is present on each thin PCB layer. If specs do not indicate otherwise, PCB manufacturers will default to 1 oz finished copper weight.

What is a 2 oz Copper PCB?

A 2 oz copper PCB has a thickness of 2.8 mils or 70 microns. It serves as the standard copper weight for internal and external PCB layers with a 3 oz finished weight. 2 oz copper enables improved layer arrangements, especially for outer PCB layers.

In PCBs, 2 oz copper offers many benefits, including enhanced reliability, stability, and compatibility with etched PCBs. For standard internal layers, 2 oz PCBs adhere to 70μm thickness. This is commonly used as the starting point for 3 oz finished boards.

While more common in rigid PCBs, 2 oz copper is gaining traction in flexible PCBs, despite the prevalence of lighter 0.5 oz and 1 oz weights. However, heavier copper weights like 2 oz must be evaluated against flexibility needs.

Comparing 1oz Copper Thickness PCBs vs 2oz Copper Thickness PCBs

1.Copper Weight and Thickness Range

The copper weight of a PCB is measured in ounces per square foot. A 1oz copper thickness PCB has a copper weight of 1.4 mil/35 μm, while a 2oz copper thickness PCB has a copper weight of 2.8 mil/70 μm. Both types of PCBs offer standard thickness of 0.062 inches, and custom thickness options are also available.

2.Current Capacity and Heat Dissipation

One of the key differences between 1oz and 2oz copper thickness PCBs is their current-carrying capacity and heat dissipation capabilities. A 2oz copper thickness PCB has a higher current-carrying capacity and improved heat dissipation compared to a 1oz copper thickness PCB. This makes 2oz copper thickness PCBs suitable for applications that require higher power and better thermal management.

3.Voltage Drop and Thermal Conductivity

In terms of voltage drop and thermal conductivity, 2oz copper thickness PCBs outperform 1oz copper thickness PCBs. A 2oz copper thickness PCB exhibits lower voltage drop and higher thermal conductivity, which is beneficial for applications where voltage stability and efficient heat transfer are crucial.

4.Cost and Applications

While 2oz copper thickness PCBs offer superior electrical and thermal performance, they come at a higher cost compared to 1oz copper thickness PCBs. Therefore, the choice between the two depends on the specific requirements of the application. 1oz copper thickness PCBs are suitable for low-power applications, while 2oz copper thickness PCBs are ideal for high-power applications that demand robust electrical and thermal characteristics.

5.Considerations for Choosing Copper Thickness

When selecting the optimal copper thickness for a PCB, it is essential to consider the current capacity requirements, thermal management needs, voltage drop tolerance, space constraints, manufacturing capabilities, and cost implications. Evaluating these factors will help in determining whether a 1oz or 2oz copper thickness PCB is best suited for the intended application.

There are two key considerations for optimal PCB copper thickness:

  • Current capacity for acceptable heat rise
  • Mechanical strength based on thickness, holes, and vias

Some key points include:

  • Evaluate circuit current needs. Higher current requires 2 oz.
  • Consider thermal management. 2 oz better dissipates heat.
  • Assess voltage drop tolerance. 2 oz has lower drop.
  • Check space constraints. 2 oz needs more space.
  • Discuss manufacturing capabilities and costs.
  • Weigh cost against specific benefits of thickness.
  • Match to demands of application. 2 oz suits high power.

Get Quality 1 oz or 2 oz PCBs

At VictoryPCB, we deliver high-quality, tailored PCBs to meet unique client needs. With extensive experience and advanced manufacturing, we guide you in choosing between 1 oz vs 2 oz copper PCBs. Contact us at sales@victorypcb.com to partner with a PCB manufacturer who understands copper weights and provides tailored, high-quality PCBs. Let us help bring your designs to life.