General Information

Ceramic Substrates are used in many electronic applications where a thin insulating layer of thermally stable material is required to conduct heat away from electronic components whilst electrically insulating them.

The ceramic substrate is produced in sheets sometimes in excess of 100m square. Most components when built are a fraction of this size, but the sheet allows large numbers of components to be cut or metallized in a single process. The benefits to ceramics users for different applications can be significant as the use of the material is extremely cost effective. Components that are under 2mm thick and where the design is suitable for laser machining, can be produced without laying down tools and to a rapid lead time. Small to medium batch runs are very cost effective and many companies outside the electronics industry now use the availability of these materials in mechanical or electrical applications.

The substrates can be machined in a variety of ways...

Laser Machining

A variety of lasers will cut through the thickness of the substrate, the accuracy depending on the laser and the thickness of the material but in general ±.50mm can be achieved on material up to 1mm thick. The laser can be set to cut curves, holes or straight lines and is best suited for complex shapes. Thickness of over 1mm can be cut but at slower speeds and with a poorer edge quality. This will worsen on the basis of the thicker the material used.

If the laser is used to cut straight lines then a cheaper process can be used where the laser does not completely cut the material but stitches a series of holes close together, allowing the substrate to be cracked along the laser line - this process leaves a rougher edge but also reduces costs. Hole drilling with a laser depends on the hole and it's position in relation to other features, tolerances of.001mm have been achieved on holes of .009mm diameter when cutting .200mm material.

Slicing and Dicing

Where very small regular shaped parts are required with a high edge definition, then using high speed, low vibration saws to cut through up to 3mm of material is the answer. Depending on the material and it's thickness, blades of less than .100mm can be used with the machine programmed to cut 150mm long pieces of material. The machines can be set manually to cut alongside a machined feature or automatically to create a grid of squares or other regular forms. Features can be machined into a substrate by cutting channels into the material but not completely through.

Water Jet Cutting

This process is similar to laser cutting and can cut complex shapes out of flat plates but is normally used on thicker pieces of softer ceramics. The cut must pass through the material and as the energy is dissipated, the cut widens and becomes irregular on the back face.

Substrates can also be machined over the surface to improve flatness and parallelism and in some instances polished, if this is achieved pre laser machining or slicing, it allows large numbers of small parts to be ground in a single operation. On materials such as Zirconia and Alumina, laser marking is also available where parts can be permanently marked for trace ability.