Metal Core PCB Design Guidelines in Altium Designer

Most Printed Circuit Boards use a thick FR4 core layer to provide structural stability and interior copper layers for a multilayer PCB. If issues like thermal dissipation and even greater structural integrity are required in your particular application, you might consider designing with a metal core PCB. These Circuit Boards require some specific design guidelines regarding component selection, placement, and multilayer routing. With Altium Designer, you can satisfy important design requirements on metal core PCBs for any application.

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A unified PCB design package with multilayer PCB design and layout tools.

Most PCBs used in consumer electronics, and even in more demanding applications like automotive and aerospace, use standard PCBs built entirely around epoxy resin. Printed Circuits on epoxy resin contain an FR4 core plated with copper foil on each side. Multilayer stackups are built by etching the copper layer on the core, followed by placing a low thermal conductivity resin layer as a prepreg between the next layer in the stack. This stack is then bonded using heat and pressure. After successive steps, you have a multilayer PCB.

Metal core PCBs have a similar structure for layers that surround a metal core. The three common materials used in metal core PCBs are copper, iron, and aluminum. The external layers have similar properties as a typical FR4 PCB, while the metal core provides some specific advantages in different applications, such as different thermal conductivity values.

Advantages of Metal Core PCBs

Any board that will contain active components that dissipate a significant amount of power as heat can benefit when designed on a metal core PCB. On a normal PCB, the interior FR4 layers are relatively poor thermal conductors, and heat is normally dissipated from active components using vias and thermal lands. A metal core has higher thermal conductivity, allowing them to easily dissipate heat away from active components. This allows heat to be more uniformly distributed around the board, preventing hot spots that can form in PCBs on standard FR4.The laminates used in metal core PCBs use thermal conductivity to dissipate heat faster than FR4, which also helps keep active components cooler, leading to increased performance and lifetime. As one example application, lighting systems that use high power LEDs produce a significant amount of heat. Working with a metal core PCB provides some natural reflectivity for any light that travels towards the substrate, increasing the brightness from these devices. The metal core also allows heat to be quickly moved away from the LEDs, preventing them from burning out.

Metal Core PCB Applications for Military and Aerospace

Military and aerospace are two areas where Printed Circuit Boards must be able to withstand repeated thermal cycling, extremes of temperature and moisture, and frequent mechanical shocks. Metal core PCBs help satisfy these operational requirements as they provide greater structural integrity and thermal conductivity, allowing them to withstand greater shocks than a Printed Circuit Board on FR4. The higher thermal conductivity of these boards helps ensure that the temperature distribution in these boards is uniform during thermal cycling, which prevents hot spots from forming near active components.

• FR4 PCB and metal cores boards are not your only options for PCB substrate materials.Learn more about selecting alternative substrate materials, such as aluminum PCBs.
• Metal cores are just one option for aiding thermal management in your PCB. Other passive techniques are useful for keeping your boards cool.

  Learn more about working with thermal pads or thermal paste.

• If you’re building a brand new circuit board with a metal core PCB, you’ll eventually need to move your device off a breadboard and build a PCB prototype.Learn more about prototyping with metal core PCBs.

The layer stack manager in Altium Designer

Metal Core PCB Components

From an electronics design aspect, components for metal core PCBs, such as aluminum PCB boards, are not particularly different from those used on any other PCB. With a metal core PCB, you’ll need to use surface-mount components rather than through-hole components. Using through-hole circuit board components in plated vias will connect pins on the component to the inner metal core, creating a short circuit around the component.

Sourcing Circuit Board Components for Metal Core Manufacturing

Whether you are planning to manufacture a PCB on FR4, a rigid-flex PCB, or a high thermal conductivity metal core PCB, you’ll need tools in your design software for sourcing circuit board components. There is no reason you should have to manually browse distributor websites and manually copy information into a word processor to create your bill of materials. With Altium Designer, you’ll have the tools you need to source your components and generate fabrication files for your printed circuit board manufacturer.

• There are a number of steps involved in fabricating any circuit board. The right design choices can expedite the process and help you avoid unnecessary redesigns.

  Learn more about designing for PCB fabrication.

• Your manufacturer will need a complete documentation package that shows all fabrication aspects and components that appear on your metal core PCB.

  Learn more about generating a complete documentation package for your manufacturer.

• Sourcing components for any PCB can be difficult. Having access to the right supply chain management tools in your PCB design software can ease the process and reduce manufacturing lead times.Learn more about component sourcing with Chris Calvi.

Sourcing SMT components for a metal core PCB

Metal Core PCB Design in a Unified Environment

Designing a multilayer metal core PCB can be a difficult process if you don’t have access to the right design tools. You’ll need layout tools that allow you to accurately place components, route traces, define vias, crosscheck heat and thermal conductivity loads, and many other aspects that go into designing any PCB. When it comes to metal core PCBs, you’ll need a complete library of stackup materials and a layer stack manager that allows you to customize the structure of your board for your particular application.

Altium Designer: The Only Integrated PCB Design Environment

When you work with Altium Designer, you’ll have access to a full suite of PCB design tools that ease the design process for any Circuit Board. You’ll be able to customize your layer stack with a metal core and define the material properties of your substrate. Other design platforms separate important features into different programs, while Altium Designer gives you access to important layout and analysis tools in a single program.

• The rules-driven design engine in Altium Designer allows your design tools to be integrated into a single program. No other PCB design platform gives you this level of accessibility.

  Learn more about Altium Designer’s rules-driven design environment.

• Working with any metal core PCB requires access to a complete library of standard materials. Altium Designer includes an extensive stackup library for multilayer PCBs, including metal core PCBs.Learn more about Altium Designer’s stackup materials library.
• When it comes time to manufacture a metal core PCB prototype or move on to full-scale production, you’ll need supply chain visibility and documentation tools that make the transition easy.Learn more about the bill of materials tools in Altium Designer.

Other PCB design software companies leave you on your own to find the resources you need for success. Instead of leaving you to fend for yourself, Altium gives you access to the AltiumLive forum, design tutorials from industry experts, webinars and podcasts, and an extensive knowledge base. No other PCB design software company gives you this many resources for success.

Other PCB design platforms force you to navigate a basket of different programs with inconsistent interfaces, data formats, and workflows, leaving you prone to design errors and sapping your productivity. Instead of working with an outdated design process, it’s time to switch to the only design platform that unifies your critical design tools under one roof: it’s time to try Altium Designer.