Sapphire Cutting with picosecond lasers

Sapphire Cutting, Sapphire dicing, Sapphire drilling, Sapphire scribing

Sapphire cutting is currently one of the largest emerging markets in laser materials processing. Sapphire is one of the hardest existing transparent materials. Its mechanical and optical properties made it the ideal and precious choice for various components like cover glasses of watches, displays of mobile devices, protection windows for cameras, or LED carriers. Sapphire cutting with solid state lasers (e. g. lamp-pumped solid state lasers) is well known since many years and has become a state-of-the-art industrial process. 

Sapphire wafer and substrate applications include:

Microelectronic IC applications

SOS Silicon-on-Sapphire

Growth of superconducting compounds / Gallium Nitride

Infrared detectors

Hybrid microelectronics

Polishing carriers

Hostile environment

Optical transmission from ultraviolet to near infrared

High temperature

Radiation resistance

The sapphire parts are cut out from circular, rectangular or square wafers. Classical CNC machining is most commonly chosen as cutting process, despite its well-known disadvantages compared to laser cutting (lower speed, wear, larger kerf width, and material loss). If the shapes and radii are getting more complex, laser cutting is in any case the first choice. Lamp-pumped solid state lasers are widely used in the watch industry to cut and drill sapphire. However, those lasers reach their limits for consumer electronic applications (limited beam quality, spot size, and average power), and are rarely used. Ultra-short pulsed lasers, e.g. picosecond lasers, are more appropriate and are frequently used for sapphire cutting applications. 

This approach will be described in more detail in the following chapters.

Typically, the quality requirements of the cut sapphire parts are very high.

The key requirements are:

■ No micro-crack formation

■ No or minimum chipping

■ No or minimum cutting taper

■ No burr, splatters or droplets

■ Clean edge quality

■ Parts fall out of the base material

■ Minimum material loss

■ Part thickness up to 6 mm

■ High cutting speed

We offer our sapphire sheet laser cutting method for manufacturing screens and covers of various shapes and sizes, based on sapphire scribing technology.

This technology involves internally damaging the sapphire using ultrashort laser pulses to allow easy and precise breaking of material. It is suitable for sapphire sheets and wafers up to 330 μm thick and allows scribing speed of up to 300 mm/s.