Aluminum Nitride (AlN) is the best available thermally conductive material (170 W/mK) that is also a strong electric insulator. It is therefore used in a variety of applications where heat needs to be transferred away from a component. Furthermore, it has a low coefficient of thermal expansions resulting in a CTE match with other materials like silicon and other ceramics. These characteristics make AlN a perfect material for packages and sub-mounts of power components like power LEDs, high powers IC, high voltage inductors,… More and more it is also used as substrates for ceramic printed circuit boards in high power modules, f.e. GBT, electronics drivetrains, power management modules, specialty lighting, onboard chargers, … or in environments where a very low operating temperature is needed like quantum computing, superconductors, cryogenically freezers,….
Our metalized Aluminum Nitride substrates come with a 1oz electroplated copper layer on one or both sides so you can prototype your own Alumina ceramic PCB using a photo-etching process or by milling a profile in the copper layer(s). These metalization AlN substrates are perfect for universities, high schools, research institutes, start-ups and R&D departments that want to test their application on a ceramic core circuit at a reduced cost.
In case you need high quantities, a different dimension, thickness, copper thickness or would like to have a full ceramic PCB manufactured, please contact us here.
- Great thermal conductivity (170 W/mK)
- Low Coefficient of Thermal expansion (3-4 ppm/C)
- high or very low operating temperature.
- Small dielectric loss
- high wear & chemical resistance
- high heat resistance
- high mechanical strength
- 0% water absorption
- high power LED lighting
- High-reliability applications
- Power electronics
- Photovoltaic Technology
- Quantum computing
- Space and aerospace
- Applications for hazardous environments
Alumina Nitride material properties :
|Electrical||Dielectric Constant (1MHz)||-||8～10|
|Dielectric strength||MV/m or KV/mm||>17|
|Mechanical||Density after sintering (Bulk density)||g/cm3||3.26|
|Flexural Strength (3 point)||Mpa||～380|
|Elasticity (Young's Modulus)||GPa||302|
|Thermal||Coefficient of Thermal Expansion (CTE)||ppm/°C||2～3|
|Coefficient of Thermal Expansion (CTE) RT~500 °C||ppm/°C||2.5～3.5|
|Thermal Conductivity (25°C)||W/m‧K||170|
|* Reflectivity test reference thickness of 0.5mm|
If your are not sure what conductor and surface finish you should use, you can always use this handy tool: What stackup to use for your signal layers for ceramic pcb.
Frequently asked questions about our metallized Aluminum Nitride substrates:
How to etch a copper metalized substrate?
Answer: You can use a typical PCB etchant like Ferric Chloride or Ammonium Persulphate. Homemade etchants based on hydrochloric acids and hydrogen peroxide usually do not generate satisfying results. Note that doing this etching process alone will mostly not be sufficient as a thin layer will remain. Read the next question how to solve this.
Remark! Please take safety precautions and follow all the guidelines from the etchant manufacturers. Etching can be dangerous!
After etching my circuit, a thin conductive layer remains?
Answer: This is the interface layer that ensures proper adhesion of copper to the ceramic. It is usually between 0.1-0.5um thick and its exact composition is proprietary information and cannot be shared. Contact us for guidance how to remove it.
Can I route a circuit using a CNC mill?
Answer: We honestly never tried this and advise to use a fiber laser that is capable of copper ablation. We assume it is possible but you will risk losing a lot of drills and/or breaking/cracking the substrate.
However, if you were successful and want to show the rest of the engineering community how to do it. Contact us and we will pay you the boards back in exchange for a (video) tutorial.
There is discoloration and/or stains on the copper and/or some light color on one of the sides?
Answer: this is oxidation and/or leftovers from handling during the metallization process and we try to avoid them as much as possible. Note that we advise you to clean copper layer(s) before any processing which should eliminate the stains.
How do I drill holes in the substrate?
Answer: you can drill holes mechanically using a diamond drill on a CNC or a Dremel (at least 20K RPM needed - Remember to use coolant!) but it is slow and you risk cracking the substrate. Our advice is to use a powerful laser or make it easy on yourself and let us do it for you. We have the experience in house.
I have a double-sided metalized substrate, how do I make interconnects between the layers.
Answer: there are a number of ways. You can make a hole and connect top and bottom filling it with solder or by placing a wire in it and solder it from top to bottom. Another method is to use copper rivets but control your force when applying them.
Can I use a regular solder mask on the substrates?
Answer: Most solder masks, both as an ink or as tape will adhere very good to the substrate.
What is the maximum operating temperature?
Answer: We advise staying below 200C-250C continuous operating temperature. Taking the boards through reflow is no problem but you need to consider it is hard to get the pads to follow the recommended solder profile. Expect that you will need to try several times.
I want to make an Antenna for usage above 300 C?
Answer: We do not advise the usage of these substrates for such high-temperature conditions. Better is to make a thick film printed antenna on a blank substrate. The easiest way is to order this from us online in prototype (C-Proto Alumina or C-Proto AlN) or production (Easy-online Alumina or Easy-Online AlN) volumes. Or see how we can help by contacting us.
What is the resistivity of the copper?
Answer: The copper layers are electroplated which has a resistivity of roughly 1mohm/Sq.
OCTO is the online order portal from CERcuits, ceramic PCB & substrates. Learn more or contact us in case you have a high volume program or need different/more stringent specifications.