APPLICATIONS OF ALUMINUM PCBS:
Although Power Converters and LEDs are the largest users of these
products, Automotive and RF companies are also looking to take
advantage of the benefits of these constructions. While a single
layer construction is the simplest, other configuration options are
available at Amitron, including:
1. FLEXIBLE ALUMINUM PCBS
One of the newest developments in IMS materials is flexible
dielectrics. These materials feature a polyimide resin system with
ceramic fillers which provides excellent electrical insulation,
flexibility and of course thermal conductivity. When applied to a
flexible aluminum material like 5754 or similar, the product can be
formed to achieve a variety of shapes and angles which can
eliminate costly fixtures, cables and connectors. Although these
materials are flexible, they are intended to be bent into place and
remain in place. They are not suited for applications that are
intended to be flexed regularly.
2. HYBRID ALUMINUM PCBS
In a ‘Hybrid’ IMS construction a “Sub-assembly” of a non-thermal
material is processed independently and then bonded to the aluminum
base with thermal materials. The most common construction is a
2-Layer or 4-Layer Sub-assembly made from conventional FR-4.
Bonding this layer to an aluminum base with thermal dielectrics can
help dissipate heat, improve rigidity and act as a shield. Other
benefits include:
Less costly than a construction of all thermally conductive
materials
Provides superior thermal performance over a standard FR-4 product
Can eliminate costly heat sinks and associated assembly steps
Can be used in RF applications where a surface layer of PTFE is
desired for its’ loss characteristics.
Use of component windows in the aluminum to accommodate
through-hole components. This allows connectors and cables to pass
connections through the substrate while the solder fillet creates a
seal without the need for special gaskets or other costly adapters.
3. MULTILAYER ALUMINUM PCBS
Common in the high performance power supply market, multilayer IMS
PCBs are made from multiple layers of thermally conductive
dielectrics. These constructions have one or more layers of
circuitry buried in the dielectric with blind vias acting as either
thermal vias or signal vias. While more expensive and less
efficient at transferring heat as a single layer designs, they
provide a simple and effective solution for heat dissipation in
more complex designs.
