1. Rt - 400C LT metallization
2. 800 - 1000C MT metallization
3. 1300 - 1600C HT metallization
4. 1900 - 2000C UHT metallization

Low softening point glass, Ge, filter glass, etc. are being metallized with LT while high temperature ceramics are being metallized with either LT, MT, HT or UHT.

For most of the oxide ceramics, we use LT, HT or UHT metallization while we use mostly MT for non-oxide ceramics. For most common ceramics such as alumina, sapphire, spinel, translucent ceramic, we use HT as a number choice. For black alumina of oxide less than 90% purity we use LT or MT rather than HT or UHT.

We use MT for non-oxide ceramics and zirconia regardless what stabilizer is being used.

Aluminum Nitride and Others

IJR developed special metallization material designed for non-oxide ceramics such as AlN, Si3N4, BN, SiC, B4C and few others under contracts from the US Army and Navy primarily for military applications in the areas of thermal management, high power electronics and microwave devices.

A grown oxide on fully sintered AlN has a low bonding strength of oxygen to the AlN and one of the common refractory metallization materials such as Mo/Mn has shown rather poor adhesion strength when it is applied on AlN. The poor Mo-Mn metallization in terms of the adhesion strength lead shorter life of hermeticity and therefore its reliability has been an issue, especially for high temperature electronics.

IJR system of the metallization for nitrides and carbides has been unique in terms of adhesion strength and long term hermeticity. It is designed based on a bonding mechanism of the unique metallization into the ceramic with neither molybdem oxide nor manganese oxide formation in the system. The mechanism in the IJR system doesn’t require any oxidation of the material as the Mo/Mn system does. The AlN will continuously maintain its imperviousness.

Unlikely BeO, it is not toxic and its chemical resistance is also high and is being used for both medical and non-medical fields. In various semiconductor applications, its thermal expansion is closely matched to many chip devices. Our current experience is with GaN, GaAs, SiC and of course with Si often times with one of the most powerful heat sink material carbon foam (Please see one article in Technology section, Thermal Management).

For microwave application, IJR brazes Alumina or AlN window to Cu flange for the hermetic applications regardless what the CTEs are among the parts. With purchased low-lossy AlN, IJR fabricates various dielectrics.

IJR’s thin film deposition on AlN is very popular due to the high adhesion strength of the film while many thick films such as Au, Pt, Ag/Pd, etc. originally designed for oxide ceramic show poor adhesion. IJR’s thick films are different from the common thick films designed for oxide ceramic. It is called MT metallization (Please see Metallization section of Technology section of IJR website). IJR’s thick film for nitride and carbide contains ingredients of a mixture of the various bonding agent and it is not alike with the common oxide ceramic or a mixture of glass filled thick films. Due to the uniqueness in the technology, its metallization or with a braze can go in temperature even higher than the normal thick film curing temperature with no degradation of the metallization.

Use of MT metallization:

Should you have other ceramics not listed above, please contact sales@ijresearch.com for our suggestions.

Please click for a PDF copy of the brochure, Metallization.