general rule, UV photons are absorbed within fractions of microns of the material surface whereas IR photons have a penetration depth on the order of 10’s of microns or more per pulse. All other things being equal, this means that UV photons are capable of higher precision and controlled ablation, but are slower than IR lasers. Figure 2 shows a representative plot of Etch rate (microns per pulse) vs. Fluence (J/cm2
). Fluences
below the ablation threshold show no material removal at all. Above the ablation threshold there is material removal, the rate of which increases until some point at which the curve plateaus. per pulse material removal rates. Going higher on the curve gives no payback in removal rate, so it is generally not a good idea to do so unless other factors are involved. Note also that other factors, such as taper and HAZ (Heat Affected Zone) may also be affected by the energy density on target. It should also length lasers because of non-linear effects, which in principle make an otherwise ‘transparent’ material, opaque.
some companies provide both services and systems. Contract manufacturers are an ideal resource for small runs and prototypes and can, in some cases, be more cost effective even in high volume manufacturing than large companies because of lower overhead. There is no need for a large capital expense, no equipment to maintain, and no need to hire specialized laser operators and engineers. Typically there is some recurring set up cost incurred whenever a particular job is run and there may be NRE (non-recurring engineering) if special tooling is needed. Piece pricing is dictated by the laser, complexity, number of parts per run, handling and shipping requirements. Hourly rates vary from about $100 per hour for marking jobs to $500 per hour for high power femtosecond lasers or other more ‘exotic’ laser choices.
In-house systems minimize or eliminate shipping and handling issues, can be more cost effective long term, and allow onsite QC and retention of process control. This is accompanied by a large capital expense and the need to make sure that appropriate facilities and personnel are available so that the laser system works in the best manner possible. Typical system costs are shown in Table 1 and include the laser, beam delivery components, motion control elements, vision, facilities, safety/ interlocks, shipping, training and documentation. A small IR marker with simple galvo and enclosure can sell for as little as $20,000 while a USP laser machining system, or a deposition system, can go for over $1,000,000.
Laser Marker Laser Micromachining (IR)
Laser Micromachining (UV/USP) Laser Additive Manufacturing Laser Welder
*** REMEMBER, YOU GET WHAT YOU PAY FOR! Table 1. Typical Laser System Costs
Figure 2. Etch Rate vs Fluence
Because of the wide range of available candidate lasers with differing pulse lengths, wavelengths and power outputs, almost any material can be a candidate for laser materials processing as long as the thickness and absorption are within the boundary conditions set previously. In addition, these laser tools are used in a variety of markets including medical devices (usually disposable), microelectronics, aerospace/defense, semiconductors and alternative energy.
There are many laser contract manufacturers possessing the equipment and expertise to do precision laser manufacturing, just as there are a number of systems integrators that will build a laser system for in-house production environments –
In summary, lasers provide valuable and unique opportunities for high precision materials processing. Lasers however are just ‘fancy light bulbs’ and they need the addition of a variety of other hardware and the underlying expertise in order to make them suitable for manufacturing environments. Systems integrators can provide in-house laser solutions while contract manufacturers provide a valuable resource for prototyping, R&D and even high volume production. As parts continue to get smaller, lasers will continue to play an ever increasing role in the manufacturing of next generation products and devices.
Ronald D. Schaeffer, Ph.D. is CEO and co-founder of PhotoMachining, Inc.
$20,000 - $70,000 $200,000 - $400,000 $400,000 - $600,000 $400,000 - $1,000,000 $70,000 - $200,000
www.lia.org
1.800.34.LASER
15
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32