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10X Faster Sapphire, SiC, GaN Abrading
Long Abrasive Disc Abrade Life
Vitrified Diamond Abrasive Agglomerates

Use of fixed-abrasive island discs allows sapphire to be polished 10X faster than conventional liquid abrasive slurry polishing. 


Keltech has the only system in the world that does high-speed abrasive polishing of sapphire.

6” Island Disc Samples
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Vitrified Diamond Abrasive Island Discs Allow High Sapphire Abrading Speeds

Vitrified diamond agglomerate abrasive island discs are used at very high abrading speeds to provide extraordinary high cut rates of sapphire, SiC and GaN wafers.

These discs have a wide range of  sizes and offer many different diamond abrasive particle sizes.

Sapphire is used for cell phone camera lenses, smart watch crystals, LED and semiconductor wafers. Other very hard semiconductor wafers include silicon carbide and gallium nitride. 


Millions of wafers are polished every month. Also, hard steel or ceramic industrial seals can be flat-lapped with the discs.. 

Verified Sapphire High Cut Rates And Long Island-Disc Abrade Life

Abrade tests on 2” sapphire wafers using a 6” island disc operating at 1,000 RPM resulted in an average 0.0026 inch/minute wafer cut rate for 47 sequential abrade tests runs.

The total abrade time was 60 minutes with only an 0.040” wear down of the 0.061” tall islands. There was a total of 0.160 “ removed from the sapphire wafer during these tests. Also, the cut rate of the wafers increased as the islands were worn down.

This sequence of abrade tests confirmed both the high sapphire cut rates and the island disc long abrade life. More abrade test info is described in “TECHNOLOGY” and “DATA”.

Abrasive Islands Prevent Workpiece Hydroplaning

Hydroplaning of water-spray cooled wafers at high speeds is avoided with the use of fixed-abrasive islands that are bonded to flexible polymer discs. 


Hydroplaning prevents abrading as it causes separation of the wafer surface and the abrasive particles.


Conventional liquid abrasive slurries cannot operate at high speeds without causing  hydroplaning.


Vitrified Diamond Abrasive Particle Agglomerates


During vitrification, diamond abrasive particles and glass powder are melted together in a furnace.  

The vitrified material is fractured into agglomerates that are molded into islands attached in annular bands on flexible polymer discs.  

All of the self-sharpening diamonds in the agglomerates are strongly supported by the rigid glass during abrading. 

Vitrified agglomerates provide both sapphire high cut rates and very long island-disc abrade lives, as verified with hundreds of abrade tests.


Porous Bead Filler Between Islands Cools Wafers


Use of a porous bead filler between islands provides a thin film of water that coats the wafer abraded surface and cools it during abrading action. Heating of the wafers is caused by abrading friction.

However, the thin water film allows the islands to prevent hydroplaning of the wafer when water spray coolant is applied to the disc islands rotating at high abrading speeds.

This island porous bead filler results in both high cut rates and cool wafers. Also, the island bead filler is a very distinctive feature of these island discs.


100% Utilized Diamond Fixed-Abrasive Particles

Expensive diamond abrasive particles encapsulated in the vitrified diamond abrasive agglomerates are rigidly held by solid glass.

They are slowly worn down by wafer abrading action until new diamond particles are exposed.

Each individual diamond particle is fully utilized.


Wide Range Of Island Disc Sizes

Vitrified diamond agglomerate islands can be supplied as 6”, 12”, 18” up to sizes of 60”, or more.


Island Discs Used Together WITH Abrasive Slurry Wafer Polishing

The island discs can be used together with the liquid abrasive slurry polishing system. Here, the island discs can be used to initially flatten the sliced wafers and rough polish them. Then, conventional abrasive slurry can be used to finish-polish the wafers.

Keltech Provides Abrasive Island Discs, NOT Lapping Machines

Multiple machine builders will provide the abrasive lapping machines that utilize the Keltech vitrified diamond agglomerate island discs. Keltech will supply the many island discs used annually by each lapping machine.

Samples of 6” Vitrified Diamond Agglomerate Island Discs


Keltech will supply you with a sample 6” vitrified diamond agglomerate island disc.

It can be used to abrade your 2” sapphire, SiC or GaN wafer at high abrading speeds using a simple wafer polishing set-up on one of your standard shop milling machines.

The mill 6” island disc abrade set-up is described in detail in the website TECHNOLOGY section.

Abrading of your wafers with the sample disc will allow you to explore ways to utilize the discs for the benefit of your customers.

For a sample 6” island disc just contact:


New Opportunities For Everyone

Keltech’s new form of high-speed vitrified diamond abrasive agglomerate island media provides lots of opportunities for you and your customers.

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