LASER APPLICATION
Welding
Laser welding offers a variety of benefits over other types of welding: deep penetration of precise narrow welds, small heat affected zone, low heat input, fast weld times, minimum part distortion, no secondary processing and high repeatability. Many metals can be welded including stainless steel, carbon steel, titanium, aluminum and dissimilar metals.
When defining a weld joint we refer to both the joint type and the weld type. There are two joint types: butt and lap. A butt joint is where two materials are to be welded at the seam that forms where the two materials are joined together. A lap joint is where two materials are to be joined by welding through one into the other. There are also two weld types: seam and spot. Seam welding is continuous while spot welding is intermittent. Glass sealing and glass-to-metal sealing is also accomplished with Nd:YAG lasers. Plastic welding with Nd:YAG lasers has been in development for some time and is now commercially viable with certain plastics.
Cutting
In laser cutting, focused laser light is used as the heat source to both melt and vaporize material in it's path. Many metals can be cut precisely with a laser by varying power, feed rate, spot size, and gas type and flow. Laser cutting is fast, flexible and cost effective.
Drilling
Laser drilling is the process of removing material to create through holes. Drilling can be done by percussion or trepanning. Percussion drilling focuses the beam to a spot equal to the diameter of the hole to be drilled. If a large hole is required, the laser is moved with respect to the work piece to form the desired diameter. This is called trepanning. Laser drilling is ideal for high production volumes. It is cost effective, and has no drill breakage or tool wear. Nd:YAG lasers have the ability drill unlimited hole sizes and shapes in a variety of materials including most metals, ceramics, and semiconductors.
Micro-machining
Laser micro-machining is used to produce very small parts or very small features in parts. It is similar to cutting and drilling, but on a very small scale. Features as small as a few microns can be produced using very high peak power short pulses, but low average power. The resolution of features produced is proportional to the wavelength used and the beam quality. Materials that can be micro-machined with Nd:YAG lasers include metals, ceramics, plastics, glass, laminates and composites.
Resistor trimming
Nd:YAG lasers are used for both thick film and thin film resistor trimming. Laser resistor trimming is fast, accurate and clean.
Soldering
The Nd:YAG laser is a very effective soldering tool in applications where the amount of heat introduced to the part during the process must be minimized, or where production throughput requirements dictate a very fast soldering process.
Marking
Lasers are becoming the method of choice for marking on many different surfaces including most metals and many plastics. This is because laser marking has clear advantages over other marking technologies. Printing systems require ink usage, and hazardous solvent handling and disposal. Tools wear in stamping systems. Laser marking systems, on the other hand, offer a clean, low maintenance, easily configured system for permanent marking of surfaces.
Scribing
Scribing is very similar to marking in that lines or characters are produced in the material. Scribing generally refers to a process where the finished line is the same as the kerf or beam width. Semiconductor materials and ceramics are commonly scribed materials.
Photovoltaic panel processing
Nd:YAG lasers are used for creating conductive traces in a metal layer on photovoltaic panels, and for scribing panels for breaking to specified sizes.
Heat treating
Lasers have the advantage of being able to heat treat precise areas of metals without involving the entire work- piece. Laser can provide precise heat input control to localized areas minimizing distortion, stress and cracking. Laser heat treating is time efficient, and provides access to hard to reach areas. The mass of the material being processed is generally sufficient for rapid heat removal or quenching. The enhanced mechanical and electrical properties resulting from laser heat treating will depend upon the composition of the metal or alloy.
Metal Deposition
Direct metal deposition laser systems are being used for rapid prototyping, repair of expensive components (like those used in aircraft engines) and manufacturing of fully dense parts for use as system components. Metal parts are built up by injecting metal powder into the focused spot of a high power CW laser beam. The mechanical properties of the finished parts are often superior to those of parts fabricated from traditional metal-working techniques. Metal deposition also allows for continuously fabricating parts from different alloys.
Paint stripping and Surface Removal
Certain paint stripping and surface removal applications are ideal for laser systems. Lasers offer a benefit over chemical stripping applications where waste disposal, or chemical interaction with the base material is an issue. Nd:YAG laser stripping can also be done with fiber optic beam delivery in applications where the area to be treated is inaccessible to human operators due to the hazardous nature of the environment or physical inaccessibility.
