Yield Improvement by Online Measurement and Analysis of Laser Energy Using Ophir’s Quasar

Yoram Shalev, Sales & Marketing Director, Ophir Optronics, LLC

This was demonstrated in a project undertaken recently, and is a typical example of what of multi-user systems see in the field.

A manufacturer of medical implants uses eight (8) pulsed lasers to perform cutouts on the medical implant. The accuracy and repeatability of the energy of each pulse is directly linked to the yield of the production facility.

The manufacturer has mapped the failure mode source to irregular pulse energy. His requirement is to measure the pulse energy in real time and to store the data for analysis. Another request was to make a quick and neat installation with no additional cables to be laid out in the production floor, due to clean room considerations.

The production floor is controlled from a central location through a server connected to the lasers.

Each laser fires its pulses through a beam splitter, which splits off a fraction of the pulse energy into a pyroelectric sensor, resulting in an "online" measurement system. The pyroelectric sensor is connected to an Ophir Quasar wireless interface which transmits the measurement data in real time to a server, storing the data into a SQL database. The server collects data from all eight lasers through eight Quasar interfaces, one for each laser.

The data collected includes the energy of the pulse, a timestamp, the laser ID, and a batch number.

The system is used in two different ways:

• Each pulse is examined by the software through a min / max filter. When an out of spec condition occurs, immediate action is taken to stop a faulty laser and to save the expensive raw material from being processed to an out of tolerance condition.
• The laser data is analyzed statistically on a periodic basis to detect a laser which is about to go out of tolerance and to allow the scheduling of preventive maintenance.

Quasar has enabled the system to be installed immediately, without the need to run any new cables in the existing production floor. The Quasar interfaces communicate directly to the existing server, through its Bluetooth interface.

The use of Quasar has allowed a quick increase in the facility yield by saving raw material from being processed by an out of tolerance laser and by allowing preventive maintenance to be scheduled at convenient times instead of corrective maintenance which disrupts production.