Aluminium Nitride (AlN) vs Shapal (Machinable AlN)

Published on Apr 6, 2021 | Last updated May 31, 2022

The increasing use of Aluminium Nitride (AlN) in power electronics, dissipating heat and providing electrical insulation has been an ongoing trend. The performance of Aluminium Nitride far outstrips Alumina in some critical areas. But the added cost of manufacturing AlN is a limiting factor.

The changeover from Alumina to AlN takes you from a material that is plentiful and one of the cheapest technical ceramics available, to a relative newcomer, requiring specialist furnacing in a nitrogen atmosphere and limited specialist manufacturers. While the move from one material to the other is a major step change with significant benefits, it can carry significant cost increases and longer lead times.

The move to AlN can be mitigated by using an intermediate step, a machinable Aluminium Nitride. This can help considerably when developing a structural piece of material that cannot be produced from available ceramic substrates, but requires a larger piece of material that would otherwise have to be made from compacted powder and sintered.

Machinable AlN is a hot pressed material, produced in billet form, easily machinable and readily available. This allows a way of quickly prototyping small quantities of components without waiting months for minimum order quantities of parts.

Machinable AlN, with the trademark of Shapal Hi-M Soft, is the market leader, with a 30 year pedigree. This tends to be the go to material when you have reached the extremes of temperature, thermal shock, electrical insulation, while having the ability to be machined without diamond tools.

Pure Aluminium Nitride is mechanically stronger, harder, and has higher thermal conductivity. The downside often being the lead time and the cost of diamond grinding, which can be considerable.

The transition from Alumina to a higher performing thermal material such as AlN can require tooling and long lead times. Shapal Hi-M Soft can provide the bridge, where small quantities of prototypes can be rapidly produced, trialed, and evaluated, modified in the design phase if required, and then retested, without having to place significant orders, pay for tooling, and wait for months.

The ability to rapidly make machinable Aluminium Nitride components shortens time to market and allows a fully functioning product to be tested. Many products have been developed this way and a considerable number have stayed with Shapal Hi-M Soft and not made the transition to AlN.

Aluminium Nitride Properties

This following property tables show the key benefits of Aluminium Nitride (AlN) vs Machinable Aluminium Nitride (Shapal Hi-M Soft).

General Properties

Unit
Density
g/cm3
Aluminium Nitride
Density
3.31
Shapal
Density
2.88

Electrical Properties

Unit
Volume Resistivity @ 25℃
Ωcm
Volume Resistivity @ 500℃
Ωcm
Dielectric Strength
kV/mm
Aluminium Nitride
Volume Resistivity @ 25℃
1.0 x 1013
Volume Resistivity @ 500℃
3.2 x 107
Dielectric Strength
15
Shapal
Volume Resistivity @ 25℃
1.0 x 1015
Volume Resistivity @ 500℃
3.2 x 1010
Dielectric Strength
65

Thermal Properties

Unit
CTE @ 300℃
/℃
CTE @ 400℃
/℃
CTE @ 500℃
/℃
CTE @ 600℃
/℃
CTE @ 800℃
/℃
CTE @ 1000℃
/℃
Thermal Conductivity
W/mK
Max Use Temp in Air
Max Use Temp in Non-Oxidizing Atmosphere
Aluminium Nitride
CTE @ 300℃
4.6 x 106
CTE @ 400℃
CTE @ 500℃
5.2 x 106
CTE @ 600℃
CTE @ 800℃
CTE @ 1000℃
5.6 x 106
Thermal Conductivity
180
Max Use Temp in Air
1000
Max Use Temp in Non-Oxidizing Atmosphere
1900
Shapal
CTE @ 300℃
CTE @ 400℃
4.8 x 10-6
CTE @ 500℃
CTE @ 600℃
4.9 x 10-6
CTE @ 800℃
5.0 x 10-6
CTE @ 1000℃
Thermal Conductivity
92
Max Use Temp in Air
1000
Max Use Temp in Non-Oxidizing Atmosphere
1900

* Coefficient of Thermal Expansion (CTE) describes how the size of an object changes with a change in temperature.

Mechanical Properties

Unit
Bending Strength @ 25℃
MPa
Compressive Strength @ 25℃
kg/mm2
Vickers Hardness (Hv) @ 25℃, 300g
kg/mm2
Aluminium Nitride
Bending Strength @ 25℃
335
Compressive Strength @ 25℃
2100
Vickers Hardness (Hv) @ 25℃, 300g
1100
Shapal
Bending Strength @ 25℃
300
Compressive Strength @ 25℃
100
Vickers Hardness (Hv) @ 25℃, 300g
380

Interested in finding out more and if any of our materials are the right fit for your application? Please don’t hesitate to get in touch.

Related topics:

Aluminum Nitride Material Brand PCAN1000

Aluminium Nitride

CeramAlum™

Aluminium Nitride (AlN) is an excellent material to use if high thermal conductivity and electrical insulation properties are required -- an ideal material for use in thermal management and electrical applications.

Shapal Material Brand

Shapal Hi M Soft™

Machinable AlN

Shapal Hi-M Soft is a hybrid type of machinable Aluminium Nitride (AlN) ceramic that offers high mechanical strength and thermal conductivity.

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