Saturn Electronics Provides Heavy Copper PCB Design and Fabrication Services for High-Power Applications

https://cdn.pcbdirectory.com/news/Untitled_design_12__639174482549826502.webp712370

Saturn Electronics, a PCB manufacturer that provides custom printed circuit board fabrication and engineering support for applications ranging from prototypes to complex high-performance electronic systems, provides technical resources covering heavy copper PCB design, materials, fabrication methods, stackup development, and manufacturing considerations for high-current and high-voltage applications.

Saturn Electronics has introduced a comprehensive Heavy Copper Resource Center focused on printed circuit boards that use more than 2 ounces of copper per layer. The resource is intended to support PCB designers and users with information on materials, fabrication methodologies, calculators, and design-for-manufacturing (DFM) considerations related to heavy copper technology.

Heavy copper PCBs are used where higher current-carrying capacity, thermal performance, and voltage handling are required. Saturn defines heavy copper PCBs as designs using 3 ounces of copper or more on inner and/or outer layers of printed circuit or power distribution boards. The company is UL-certified for up to 6-ounce copper on inner and outer layers and can manufacture double-sided and multilayer boards with copper weights up to 20 ounces.

Heavy Copper Design Considerations

The resource center outlines key reasons for using heavy copper, including higher voltage operation, impedance control, and reduced electrical resistance. It also identifies the primary design factors that influence heavy copper layouts:

• Trace length
• Trace width
• Copper thickness

Saturn notes that increasing copper thickness can improve current-carrying capability, increase routing density, reduce layer count requirements, and support thermal distribution and heat dissipation in power electronics.

Typical applications highlighted by the company include:

• High-power heat dissipation systems
• Planar transformers
• Power converters
• Electric vehicle and photovoltaic systems
• Battery management systems
• High-voltage electronics

Design-for-Manufacturing Rules

The company explains that while many standard PCB DFM practices remain applicable, heavy copper designs require additional attention to spacing and dielectric thickness. For spacing requirements, Saturn states that lateral etching effects require etch-factor or etch-compensation adjustments during fabrication. The company typically adds 0.001 inch to each side of a feature for every ounce of base copper. Dielectric thickness also becomes a critical consideration. To prevent resin starvation and voids between heavy copper layers, additional prepreg material may be required compared with conventional PCB constructions.

Copper Laminate Options

The resource center reviews several heavy copper laminate approaches available to designers. Industry-standard UL-certified copper-clad laminates are commonly available up to 6 ounces of copper. Saturn is certified for copper weights up to this level on both inner and outer layers. The company also discusses historical use of 10–12 ounce copper laminates and notes that it has produced custom fabricated materials supporting copper weights up to 20 ounces for specialized applications.

Fabrication Methodologies for Heavy Copper Boards

Saturn details three primary manufacturing approaches used in heavy copper PCB production:

Etch-Down

A traditional fabrication process in which copper is plated to the target weight and then etched to form the required circuit features. The method is generally associated with standard process flow and supports copper weights up to 20 ounces in non-UL configurations.

Plate-Up

A process that begins with a thinner copper base and builds up copper through repeated imaging and plating operations until the target thickness is achieved. Saturn notes that this method involves greater process complexity and longer lead times.

Hybrid Construction

A design approach that combines buried heavy copper structures on inner layers with standard copper weights on outer layers. This enables support for high-power requirements while maintaining compatibility with finer-pitch components.

The company also compares the three methods across factors such as cost, process complexity, material capability, supplier availability, DFM requirements, copper-weight variation, lead times, sidewall geometry, and SMT compatibility.

Layer Stackup and Thickness Management

The resource center includes guidance on stackup development for heavy copper PCBs. Saturn identifies four key factors that determine stackup requirements:

1. Layer count
2. Layer design
3. Copper weight
4. Minimum dielectric thickness between layers

To prevent resin starvation between heavy copper features, additional prepreg layers may be required. Stackup design therefore balances copper thickness, dielectric spacing, overall board thickness, and layer count.

For applications where overall board thickness is limited, Saturn describes the use of layer-fill ink technology. Instead of relying solely on prepreg to fill etched gaps, epoxy-based layer-fill materials can be applied to reduce the amount of prepreg required between layers while maintaining structural integrity. The company reports producing multilayer designs incorporating copper weights up to 20 ounces across 20 layers using these techniques.

Support for High-Voltage and Power Electronics Applications

Saturn states that heavy copper PCB technology is particularly relevant for power electronics requiring high current capacity and high-voltage operation. The resource center includes technical information related to power electronics applications, fabrication challenges, material selection, and design methodologies intended to support engineers working with advanced heavy copper PCB designs.

Click here to learn more about the heavy copper PCB design and fabrication.