alumina PCBs
Alumina PCBs are highly specialized circuit boards that enable high-performance applications with extreme power, frequency and environmental demands. They offer superior electrical insulation and thermal conductivity, high mechanical strength and good chemical resistance properties. They are used in aerospace and defense electronics, LED lighting, high-power motors and other demanding electronic applications.
alumina pcb have higher costs than standard FR-4 PCBs due to exotic material selection and processing. They can cost $50-$300 per square foot for a multilayer board in small volumes. This is mainly driven by the specialized materials and complex processes required for fabrication.
Ceramic substrates are made from aluminum oxide molecules arranged in a crystalline structure bound through strong ionic and covalent bonds with no polymeric components as found in FR-4 boards. They undergo a proprietary manufacturing process called tape casting, binder burnout and high temperature sintering to form the baseplate of a ceramic circuit board. Conductors are then deposited on the alumina substrate using screen printing or thick film technology. Alumina is available in single-layer and multilayer designs.
Can alumina PCBs be used in consumer electronics?
The metallized copper on the alumina surface directly bonds to it without any intermediate adhesive or glue layer, making the alumina-copper interface very robust. This design makes alumina boards very stable in harsh environments and resistant to high temperatures. Alumina’s high thermal conductivity of 18-36 W/mK allows effective heat dissipation and good electrical insulation. Alumina’s dielectric constant is between 9.0 and 10.1 across the functional frequency range from DC to microwave, which delivers good high-speed electrical performance.
This unique combination of electrical and thermal performance, along with the excellent gas tightness properties of alumina, makes these boards ideal for power electronics, hybrid microelectronics and electronics packaging. Alumina is also resistant to corrosion and chemical damage, and offers good thermal shock and vibration resistance.
Advanced alumina circuit boards are also used in medical and industrial devices. These include implantable medical devices, automotive control systems and lasers. These devices operate at very high temperatures and require a durable, reliable circuit board to protect the critical components from heat and other harmful effects. Properly fabricated alumina circuit boards can operate reliably for 50 years or more, with consistent, trouble-free function. This is due to tight dimensional and material control during production, minimizing flaws or latent shorts/opens that can cause early failures in operation.
Alumina circuit boards are also suited to high-speed electronic applications, due to their extremely low dielectric constant and very fast switching speeds. They can withstand very high frequencies up to 500 MHz, with good EMI suppression and low parasitic effects.
Alumina PCBs are fabricated by applying a conductive copper layer to a sintered alumina baseplate, in either single or multilayer configurations. The alumina-copper interface is robust, allowing very thin cores down to 6 mils thickness. Advanced alumina substrates allow for vertical integration of active and passive components, mezzanine modules, and high pin count chips. They can also be used to create microwave cavities, route high density traces between layers, and support a variety of other innovative features.