The successful development of Tokuyama’s Shapal Hi-M Soft machinable ALN/BN composite in North America has led to the choice of Precision Ceramics USA as the official distributor for their range of AlN powders.
The use of aluminium nitride in high-end electrical substrates is already well known and in terms of thermal conductance, there are few other technical ceramics to match it. AlN’s strengths, which include a good co-efficient of thermal expansion, good electrical insulation and thermal shock resistance and excellent thermal conductance in excess of 180w/m/k, are key to its success. Largely driven by these unique properties and the restricted use of Beryllium oxide (BeO), the demand for aluminium nitride outside the standard confines of substrates – flat plates simply laser machined – has seen a marked growth in recent years especially for trial components where small volumes required a transition material. For this purpose, Shapal Hi-M Soft, a machinable ceramic compound and a unique mixture of AlN and BN is the perfect candidate, enabling rapid production of small quantities of trial parts. With low tooling costs and a quick turnaround, this process has certainly provided a stepping stone towards the more extensive use of pure aluminium nitride. The thermal conductivity of aluminium nitride greatly outperforms that of aluminium oxide (alumina) by a factor of 7 to 1 and coupled with a coefficient of thermal expansion matched to silica, a whole new field of applications has been created in the semiconductor, aerospace, nuclear, plasma, research and electronics. Within these industries, the increase in techniques using aluminium nitride to create ceramic components now includes extrusion as well as die and iso-pressing, tape casting and hipping. Some work has also been carried out to injection moulding AlN but so far only small components have been produced. Aluminium nitride can be metalized with tungsten to allow nickel plating and the subsequent attachment of LED’s, electronic components or metalwork to create a complex assembly.
Tokuyama AlN Powder Range
The high purity powder range we now offer includes a ready to press powder, granulated and complete with binder, through to the highest purity electronic grade for the very best thermal management. Tokuyama’s powders are available in volume and are the mainstay of the world’s ALN production. With their low oxygen content, low metal impurity levels and excellent sinterability, they are suitable for both hot-pressing and pressure less sintering. The powders are available with and without binder and with and without sintering aids
Grades
Tokuyama Grade H (Number 1) Grade
This standard high purity powder has a specific surface area of m3/g and a pressed density of 1.68gm/cc when pressed at 19.6 mpa. Impurity levels O
0.83 wt% C
210 ppm Ca
230 ppm Si
43 ppm Fe
12 ppm The fine particle distribution, with a mean particle diameter of 1.13 microns, gives a consistent material, translucent when either hot pressed or pressure less sintered. This powder is the Building Block for the H-T granule but without the binder or sintering aids that the granule contains. The material is supplied in 10 kilo dry nitrogen packed containers
Tokuyama E Grade
This special electronic grade has reduced Ca, Si and Fe levels of 2-9 ppm, improving the thermal conductance of the finished material. Apart from the reduced impurities, the material is similar to the H Grade with no added binder or sintering aids. The material is supplied in 10kg dry nitrogen packed containers.
Tokuyama H-T granule
A granulated free flowing powder complete with sintering aid and organic binder. This ready to press powder is suitable for both press and iso-press compaction an for tape casting when solvent is added. The powder is available in standard 10kg dry nitrogen packed containers but smaller amounts are available on request. This high purity powder enables efficient manufacture of ALN components with a proven binder and sintering system.
