The manufacturing of a circuit board involves the use of several materials. Aluminum is a common material found in ceramic PCB. It is not only common, it is the most-effective material used in ceramic PCB. The two most common ceramic materials used for a ceramic PCB are aluminum oxide (Al2o3) and aluminum nitride (AIN).
Al2o3 features much higher thermal conductivity than AIN. However, a ceramic printed circuit board is a great option for several applications. Our focus here is on Al2o3 ceramic PCB. Therefore, this article will shed more light on the properties and importance of Al2o3 PCB.
What is Al2o3 PCB?
Al2o3 PCB or Alumina PCB is a circuit board that comprises Al2o3. It is a type of ceramic PCB features good properties which include low CTE and good thermal conductivity. Also, Alumina comprises many isomorphic crystals and higher purity. The most crucial property of this ceramic PCB is its thermal conductivity which is between 15W/mK to 50W/mK.
This ceramic PCB is ideal for use in a wide range of applications. Some of its application areas include LED boards and high frequency devices. Al2o3 PCB features ceramic material for multilayer packages. This PCB has undergone several layers of experiment. Also, it has developed over the years.
Al2o3 is an engineering material that provides great electrical and mechanical properties. Alumina is the most used ceramic material. Also, Alumina PCBs comprise a great amount of Al2o3. The high thermal stability of alumina boards helps to enhance the thermal efficiency and performance of the circuits used in automobiles.
Alumina PCBs can feature 95.5%, 75%, and 96% alumina substrates. Higher purity indicates denser appearance and smoother surface. These circuit boards offer excellent electrical insulation. Also, alumina as a ceramic material features high biocompatibility. The material properties of alumina PCB contribute to its performance.
Types of Alumina PCB
Al2o3 PCB comprises three types of alumina oxide. This includes 99.5% alumina substrate, 99.6% alumina substrate, and 96% alumina substrate.
99.5% Alumina ceramic substrate
This alumina PCB is widely used in smaller grain size applications. Also, the finish on the surface of this PCB is 99.5% and can achieve a 2u-in maximum finish. This is because it is a large grain size. Also, the materials have less thermal conductivity and flexural strength. One of the benefits of this substrate is that it is available in other thickness and larger sizes.
99.6% alumina PCB substrate
This substrate is widely known for its standardized thin-film substrates. Therefore, this contributes to its popularity in the PCB industry. 99.6% alumina substrate is ideal for use in evaporated and sputtered metals. Also, this substrate features a high purity level. There is a smaller grain that allows it to offer a smoother result without fewer surface defects.
Also, this substrate has below 1u-in 99.6 Alumina surface roughness. Therefore, this indicates low thermal conductivity, good dielectric properties, and great electrical insulation.
96% alumina PCB substrate
This alumina substrate is very common. Also, the majority of microelectronic applications require alumina PCBs. The standard format needed for this type of application is the thick film substrate. The 96% alumina PCB substrate is used for designing hybrid microelectronic circuits.
96% alumina substrate is effective for building hybrid devices. This is because of its high technical quality and availability. Also, it provides good thermal conductivity and low coefficient of thermal expansion.
Al2o3 PCB Manufacturing
Alumina is an important material used for fabricating printed circuit boards. Also, alumina PCB materials feature unambiguously diverse properties. This ceramic PCB is specially made of ceramic components. Also, the properties of alumina are different from other metals. Therefore, this establishes a major difference in the fabrication of Al2o3 PCB than the others.
Alumina PCB has some purposes it serves in the PCB industry. Where other PCBs aren’t applicable, Alumina is the perfect option to choose. The rigid and strong material used in Alumina PCBs offer significant support to electronic components.
Al2o3 is a perfect substitute to include for mounting on the PCB surface. The performance is great enough when compared to other materials. Also, there is higher temperature consistency compared to other materials. The only limitation of these materials is that it can be more expensive than other usual materials. However, this occurs when you use it for some high-grade devices.
Alumina PCB requires no dielectric layer between the core and the circuit. Also, PCBs that comprise alumina are usually thicker. Alumina PCB requires complicated procedures at high temperatures irrespective of the manufacturing process adopted.
The manufacturing process of a ceramic PCB involves several steps. The direct bonding copper is essential during manufacturing. Ceramic printed circuit boards offer strong thermal dielectric. This metal base PCB features the thick film printing and thick film process. The surface finish used for alumina ceramic PCB matters. Immersion gold is a good example of surface finish for aluminum oxide PCB.
Direct plated copper technologies are widely used in the manufacturing process. Also, direct plating copper impacts the performance of a board.
Properties of Al2o3 PCB
Alumina oxide is a common material used in fabricating ceramic PCBs and packages. Also, alumina boards offer great mechanical and electrical properties which make them highly preferred for fabricating circuit boards. The absolute material properties of this PCB includes:
Low thermal conductivity
The thermal conductivity of this PCB ranges from 15W/mK to 50W/mK. When the IC or LED produces high heat, the heat directly and quickly transfers to the alumina PCB. Therefore, there is no need for an insulating layer when using an alumina board.
High melting point
The melting point of a 96% alumina substrate is 1400oC. 99% alumina substrates have melting point of 1600oC.
Great hardness and electrical insulation
Alumina PCBs feature excellent electrical insulation. Due to this property, this circuit board is widely used in high-performance applications. The reflectivity test reference thickness helps in determining the thickness of this PCB.
Lower coefficient of thermal expansion
The coefficient of thermal expansion of this ceramic PCB matches components. Also, the CTE ranges from 6 ppm/oC to 8 ppm/oC. Therefore, the lower coefficient of thermal expansion results in less stress on solder joints.
Advantages of Alumina PCBs
Ceramic PCBs offer a lot of advantages. Below are the most upgrading benefits of Al2o3 PCBs:
- It comprises rigid and strong material that boosts durability
- Ensures ideal mechanical strength in the ceramic PCBs
- It restricts outgassing
- Features great compressive strength
- This ceramic PCB offers excellent gliding properties and low density
- Also, it provides enough light reflection as a result of its white material
- It features high operating temperature which ranges from 350iC to 1500iC
- The package size is small due to the possibilities and integration in multilayer applications
- Also, the hermetic packages allow 0% water absorption
- This ceramic PCB contributes to unmatched wears and corrosion resistance
- Also, it offers more excellent performance in high-frequency applications
- It is relatively low cost
Ceramic substrates are commercially available material. These substrates offer great electrical and thermal properties. The lower expansion coefficient and high temperature resistance are examples of these properties. Al203 PCB is ideal for different applications. We at RayMing provide quality Al2o3 PCB at competitive pricing.