Candela used Owens Design Inc. to design and manufacture it optical surface analyzers.

Candela Instruments (Fremont, CA) supplies optical surface analyzers (OSAs) to the data storage industry. The company needed to quickly move its disk surface scanning technology into full production. The company had proven the technology with a manually loaded machine. But it now wanted to quickly expand the sensing capability within the thin film magnetic disk industry. This meant that a fully automated in-line process was needed.

Automation parameters, such as cassette feeding and integration to factory systems, needed to be addressed. Disks had to be loaded with precision, scanned on both sides, and handled at high speed. There were space-constraint issues, and costs had to be kept low.

Candela chose Owens Design Inc. (Fremont, CA), an equipment manufacturer with a reputation for fast product development lead times and close collaboration with its customers.

Once the specifications were finalized, Owens began developing the equipment. It designed a custom robotic manipulator to precisely load of the disk in the vacuum chuck—a mechanism that accepts and secures the disk for high-speed rotation. The robotic arm has a direct-drive rotational axis that enables high-speed disk flipping and allows for dual-sided measurement.

The first system was ready for high-volume production in 12 weeks. The machine, known as OSA 5120, performs optical analyses on thin film magnetic disks with speed and sensitivity. It can operate under full automation or stand alone.

To cover a comprehensive spectrum of metrology and defect applications, the analysis incorporates five measurement methods:

  • ellipsometry.
  • reflectometry.
  • scatterometry.
  • Kerr Effect microscopy.
  • optical profilometry.

At the heart of the system is a Q-polarized light source that combines P and S linear polarizations to optimize phase-shift detection. The light is focused on the disk. The light is absorbed, reflected and scattered by the surface. The presence of a film or magnetic defect will introduce a phase-shift in the reflected light.

“We chose Owens Design to help reduce product development times and introduce an outstanding product to our customers. They have provided a complete outsourcing solution and helped make our automated OSA product a tremendous success,” says Rusmin Kudinar, president of Candela Instruments.

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