Originally Published MPMN June 2005
The Cutting Edge of Laser Processing
Machines and technologies make an imprint on various substances
|Equipment for direct part marking is available on a rental basis from Laser Depot.|
The machines create markings on a variety of materials, including metals, such as stainless steel and gold, and plastics, ceramics, and coatings. And in a field where smaller is better, the sizes and thicknesses that can be achieved keep shrinking. Read on for an in-depth look at some recent happenings in the world of laser processing.
Laser Produces Fine Markings on Precious Metals and Plastics
A designer and manufacturer offers resistance welding and reflow soldering power supplies, heads, monitors, and accessories for both large-scale and fine-spot applications that require precision metal joining. Unitek Miyachi Corp. (Monrovia, CA) has introduced a diode-pumped solid-state laser marker that produces fine markings on precious metals and plastics. The Model LMV1000G is specifically designed for high-speed precision marking applications. Complementing the company’s existing marker products, the equipment offers a 532-nm wavelength laser output suitable for clear marking. The output reportedly also expands the types of materials that can be economically laser marked. For example, machine- and human-readable marks on gold-plated electronic components can be performed without removal of any of the gold. As a result, the corrosion resistance and electrical properties of the plating are maintained.
The laser marker uses Vanadate technology, Nd:YV04, an alternative to Nd:YAG. The lasing medium and the end-pumping technology offer many advantages, including high peak-power density, short Q-switch pulse durations, and good beam quality. Small spot sizes, fine line thicknesses, and small character or feature sizes are then possible to achieve. In addition, the device produces linewidths as small as 20 µm, character sizes down to 100 µm, and data matrix codes with 20-µm cell sizes, using standard-length lenses. This enables working distances to remain practical. Application development support is provided at no extra charge.
Company Rents Fiber Laser Marking Systems
Laser Depot, a div. of Precision Technology Group (Lake Mary, FL), offers an alternative to temporarily outsourced laser marking services that is suitable for direct part marking and part identification. The firm has introduced rental equipment that is reportedly easy to use and completely maintenance-free.
Incorporating fiber laser technology, the FiberTower Mini and handheld fiber laser marking system are offered at a monthly rental charge. The compact systems plug into a 100-V ac outlet for quick start-up, producing high-quality marks on production parts. They are suitable for marking metals, plastics, ceramics, and coatings. The company also offers rent-to-buy options.
Automated Laser Processing Is Provided for Shops of All Sizes
|Engraving and cutting systems from Universal Laser Systems render metal-marking compounds unnecessary.|
Laser processing can be automated in shops of all sizes with modular, sized-to-fit systems that enable hands-off conversion of raw materials into cut parts. Cincinnati Inc. (Cincinnati, OH) offers the Modular Material Handling Systems (MMHS) that optimize material flow and laser burn time. This enables long periods of unattended operation. The firm engineers, manufactures, and services the systems.
Individual shops can choose from four base systems and a variety of options to suit their needs. Systems can be configured for basic automated loading and unloading with a single laser, such as System 1. Full automation of high-volume production, employing material storage towers to serve multiple lasers that run complex mixes of parts and materials, can also be achieved. Customers can also customize automated sheet- and part-handling to their existing floor space and processing needs. Expansion and modification can be accommodated as laser activity grows and changes.
The basic MMHS-1 system consists of one or more stack carts, a sheet handler, gantry sheet transporter, unload cart or station, and Web-enabled PC control with user-friendly touch screen operation. The system removes the top sheet of raw material from a stack and transports it on the overhead gantry to the dual-pallet laser. Then, the sheet is placed on the open pallet while the previous job is being cut. When that job is finished, the pallets switch positions. At this point, the overhead gantry removes the finished nest of parts and strips them onto an unload station or parts cart. It subsequently returns to the sheet handler for the next sheet.
The sheet handler separates a single sheet from a stack of raw material using three different technologies: a mechanical peeler, fanning magnet, or air knife. This ensures that only a single sheet of material is processed. A sheet-thickness gauge verifies the correct material thickness before placing the sheet on the gantry. A vacuum lift system uses suction cups that are divided into five programmable zones to accommodate different sheet sizes.
Servodriven components are said to provide accurate and reliable performance, eliminating the need for limit switches, which can be failure prone. Remote operation and diagnostics are performed with the cell controller.
Metal-Marking Compounds Are Eliminated during the Engraving and Cutting Process
|LPKF’s ProtoLaser 100 structuring system for printed circuit board prototyping cuts and drills, and needs no chemicals.|
Universal Laser Systems Inc. (ULS; Scottsdale, AZ) offers air-cooled CO2 laser engraving and cutting systems, including a variety of computer-controlled machines. These are used for marking medical devices and making labels for medical equipment. Engraving fields can range from 16 ¥ 12 to 48 ¥ 24 in., power can range from
25 to 210 W to handle multiple laser processing applications.
ULS also provides high power density focusing optics, systems that mark metals such as stainless steel. Metal-marking compounds that are normally required when marking metals with a low-powered CO2 laser source are not needed.
The firm holds U.S. and international patents in laser technology, including one for a configuration approach that allows customers to select the platform, a laser cartridge or multiple cartridges, and accessories.
Laser Uses Milling, Drilling, and Contour Routing Techniques
An easy-to-use, self-contained laser structuring system for printed circuit board (PCB) prototyping combines a laser with the milling, drilling, and contour routing capabilities of the manufacturer’s advanced PCB plotter. The ProtoLaser 100 offered by LPKF Laser & Electronics (Wilsonville, OR) produces radio-frequency and microwave boards using a range of materials such as FR4 and PTFE-based substrates. The equipment also is used for structuring, cutting, and drilling.
The laser technology isolates the circuits from the copper layer and removes noncontacting copper between them. Therefore, boards can be structured at speeds to 1 sq in./min, with circuit paths as small as 2 mil. The 1-mil laser beam delivers sharp artwork definition, especially in corners. Since the plotter milling tools change automatically, the system runs unattended.
An optical fiducial recognition system in the laser and milling heads ensures that the laser-structured area of the PCB is precisely aligned with the mechanically milled area. The equipment requires no chemicals or external chilling systems. An integrated dust-extraction system removes all laser- and milling-generated debris, making it safe to operate in different work environments. The company’s CAM software automatically manages all tool parameters, and also the interaction between the laser and mechanical machining.