Aluminum Based PCB For Led
HOW ARE ALUMINUM PCBS MADE?
A thin layer of thermally conductive but electrically insulating dielectric is laminated between a metal base and a copper foil. The copper foil is etched into the desired circuit pattern and the metal base draws heat away from this circuit through the thin dielectric.
BENEFITS OF ALUMINUM PCBS
- Heat dissipation is dramatically superior to standard FR-4 constructions.
- The dielectrics used are typically 5 to 10 times as thermally conductive as conventional epoxy-glass and a tenth of the thickness
- Thermal transfer exponentially more efficient than a conventional rigid PCB.
- Lower copper weights than suggested by the IPC heat-rise charts can be used.
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 Xing Da, including:
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:
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.
In the most complex constructions a layer of aluminum can form a ‘Core’ of a multilayer thermal construction. The aluminum is pre-drilled and back-filled with dielectric prior to lamination. Thermal materials or sub-assemblies can be laminated to both sides of the aluminum using thermal bonding materials. Once laminated, the completed assembly is thru-drilled similar to a conventional multilayer PCB. The plated through holes pass through the clearances in the aluminum to maintain electrical insulation. Alternatively a Copper core can allow both direct electrical connections as well as with insulated through holes.
APPLICATIONS OF ALUMINUM PCBS
HYBRID ALUMINUM PCBS
MULTILAYER ALUMINUM PCBS
THROUGH-HOLE ALUMINUM PCBS