The Electromagnetic Spectrum

Whenever a laser beam strikes any material, there are three possible outcomes. First, the material may be transparent to the beam, and some or all of the laser energy will simply pass through with little or no absorption.  Second, the material may be reflective to the laser beam, and little or no energy will pass through or be absorbed. Finally, the laser energy will be absorbed by the material.

In many cases, the outcome will be a combination of these three. The significant variable that determines which of the three outcomes will be dominant and observed with a given material is the wavelength of the laser beam.  In most cases, the desired outcome can be achieved by matching the material with the laser wavelength and beam parameters for proper interaction.  In the case of lamination or a material combination, it may be an absorption contrast that is needed between these materials.  For example,  the organic layer of a printed circuit board can be easily drilled with a CO2 laser.  However, a copper layer will not be touched, and acts as an etch stop to the CO2 wavelength.  The ability to process a wide range of materials with the most efficiency is dependent on having the availability of a variety of laser wavelengths.

At ALT, we have the advantage of multiple wavelength availability.  Each micromachining request is analyzed by our engineering staff to determine the laser process or processes that will provide the best combination of quality and speed.  We typically work directly with our customer's engineers to find the optimum solution to their needs.