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IC and Hybrid Processing Equipment
News Release from: Oxford Lasers | Subject: Deep UV laser scribing system
Edited by the Electronicstalk Editorial
Team on 02 December 2002
Deep UV laser scribing system boosts LED
yields
Oxford Lasers' new deep UV laser system for scribing and dicing of sapphire wafers offers significant improvements in quality, precision and cost effectiveness over conventional methods.
Oxford Lasers' new deep UV laser system for scribing and dicing of sapphire wafers offers significant improvements in quality, precision and cost effectiveness over conventional methods For the new generation of blue semiconductor LEDs based on gallium nitride (GaN), sapphire is the substrate material preferred by most manufacturers
This article was originally published on Electronicstalk on 23 May 2002 at 8.00am (UK)
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Subcontract micromachining aids MEMS designers
Micromachining systems from Oxford Lasers can cut, drill and etch precise microfeatures quickly and cleanly into a wide range of materials used in MEMS and MEOMS applications.
Micromachining systems use solid-state lasers
Oxford Lasers has developed a new range of diode-pumped solid-state laser micromachining systems.
However, due to the hexagonal crystalline symmetry, the dicing of the sapphire wafer into individual chips is an extremely unpredictable process.
The most common method of 'scribe and cleave' using a diamond tipped scribing tool to make a shallow indentation in the surface of the sapphire leads to poor yields of usable devices as the subsequent cleave often fails to follow the scribed path.
An alternative method using a mechanical diamond saw makes deeper cuts, but the available kerf width is unacceptably large and the cost of replacing the short-lived saw blades is very high.
To overcome these problems, Oxford Lasers has developed the new UltraScribe deep UV laser scribing system.
The system can be incorporated into a manufacturing process and offers a fast and precise way of scribing 100 to 500um-thick sapphire wafers.
For groove depths of 120um, a kerf width of 20um is obtained at a cutting speed of 0.5mm/s.
Higher speeds of 5mm/s can be obtained for groove depths of 30um with even smaller kerf widths significantly less than 20um.
The small spot of highly focused energy from a deep UV laser can produce grooves with a V-shaped profile, ideal for subsequent breaking steps.
The strong material interaction at 255nm introduces very little heat into the material, thus giving much less thermal damage compared with 355nm based laser systems.
The deep UV radiation cuts sapphire with very little residue and surface debris.
To achieve the best possible accuracy of edge finish, great care has been taken in the design of the four-axis workstation to isolate the stage carrying the workpiece from vibration and to use only ultra-high precision mechanical x-y stages with 200mm travel, controlled to 0.1um resolution.
With kerf widths below 20um, the Oxford Lasers UltraScribe allows wafer design with a high density of chips and greatly improved yields.
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