FAQ

These are a family of controlled expansion, lightweight alloys composed of silicon-aluminum that have been specially developed to expansion match a range of low expansion metals and ceramics to satisfy a range of high-tech applications.

Our main business in this area is the supply of machined (and electroplated) components. We will also supply packages that include feedthrough but this is carried out in conjunction with qualified partner companies.

CE alloys possess a unique combination of physical properties – low density (less than aluminium), high thermal conductivity and high specific stiffness, together with selectable expansion coefficients in the range 5 to 17 ppm/°C. At the same time, they lend themselves to standard methods of manufacture, including machining and plating.

Compare CE alloys to other types of materials

CE alloys are true metal alloys of silicon and aluminium, whereas Al-SiC (Aluminium-Silicon Carbide) is a metal matrix composite of hard silicon carbide particles in a matrix of aluminium. Al-SiC is very difficult to machine and plate, in contrast to CE alloys which are much more amenable to these and other manufacturing operations.

The cost of CE alloy products is dependent on the size and shape of items. In general, it is similar to Kovar* and cheaper than copper-tungsten (Cu-W) and copper-molybdenum (Cu-Mo).

^{*Kovar is a trademark of CRS Holding.}

No, CE alloys are environmentally friendly materials, being composed of the two most common elements present in the ground – aluminium and silicon. This distinguishes them from other materials that are used in similar high-tech applications, such as beryllium (Be), beryllia (BeO) and nickel (Ni).

CE alloy parts are normally hermetic down to thicknesses of 1 mm.

CE alloy parts can typically be supplied up to 50 cm (20 inches) in length and breadth, but larger sizes are available on request. Contact us with your requirements.

All CE alloys can be readily CNC machined at Sandvik using proprietary technology developed by Sandvik.

Read more about machining

The absolute tolerances which we can supply to will be dependent on the size of the part and the machining method used. For CNC machining, tolerances better than ± 0.05 mm are possible. With EDM, these are typically ± 0.02 mm. Flatness to within 1 in 1000 is usual. Surface finishes after milling are normally to Ra < 1μ, but with lapping this can be improved to Ra < 0.4μ.

Read more about machining

All CE alloys can be plated with a wide range of metals, including nickel, copper, silver and gold using industry-standard processes developed for aluminium, and taking due care to follow procedures specified by Sandvik. Several plating companies are qualified to plate CE alloys.

Read more about plating and surface treatment

Housings and packages in Osprey® CE17, CE13 and CE11 alloys can be readily laser-welded with CE alloy lids. For information on welding Osprey® CE7 and CE9, contact us for details.

Read more about welding and lidding

A variety of different types of feedthroughs can be inserted into CE alloy parts as per aluminium packages.

Read more about soldering, brazing and feedthroughs

It is possible to produce threaded holes down to 1.8 mm diameter (UNC 256), by thread milling or tapping. Contact us for further details.

Read more about machining

Prototype components machined and plated to customer geometries and specifications typically take 3–5 weeks to deliver. However, if the parts need feedthroughs inserted, longer timescales should be allowed for. Contact us with your requirements.

Well-developed applications of CE alloys include:

• Hermetic packages
• Microwave and RF housing, carries and heat sinks
• Optical and opto-elecronic housings
• Carrier plates for laminate PCBs
• Guide bars for PCBs
• Carriers for gas sensors
• Heat sinks and heat spreaders
• Semiconductor processing equipment components
• Soldering assembly fixtures (e.g. for BGA soldering of modules)
• Structural parts in pick and place equipment (e.g. wire-bonders)

View more application examples