One Stop Micro

If you are new to Laser Micromachining, how would you know what your project might end up costing? Lets say you approach AcmeLaser Inc (of course, a fictitious company), would they quote on your project? And how much? Well, it all depends on what kind of a laser micromachining project you have.

There are the ordinary, run-of-the-mill laser micromachining projects. And then there the intermediate-difficulty ones, where fixturing, setup and micromachining might be complicated, but not too exotic- something similar has been done before by the AcmeLaser. Slight variations in operational or processing parameters will not kill the results.

And then there are the special ones, where every little detail has be taken care of. I am not talking about finicky or temperamental jobs. These are jobs that require an expert in the field to set up, and a good team to run it.

If your project meets 8 of the 10 criterion mentioned below, then your project might probably fit into the exotic or specialized category. Some of the characteristics of these difficult projects are:

1. Technologically Challenging: One or more of the following may apply. A few examples are given.

• May require the use of more than one type of laser. For example: A 2-step process.
• A laser with very specialized beam characteristics. For example: Perfectly circular and homogeneous energy beam.
• A laser with near-constant power per pulse, even after several hours of continuous operation.
• A motion system that is precise and accurate to a very high degree. For example: If you want +-0.5 microns over 200 mm of travel, you have to pay for it.
• Beam delivery components that are complicated to design or integrate. For example: You want the beam waist to be the same size over 2mm (nearly parallel).
• Requirement of very high energy density on work surface, but limited by wavelength (generally, lower the wavelength, the lower the average as well as peak power and higher the cost, maintenance, beam delivery etc). For example: extra pure glass, or diamond.
• Unusual fixturing or parts handling requirements. For example: Direct-load from cassettes, with double side registration and machining.
• Unusually contoured parts. For example: Some medical devices fall into this category. Need to map a 2.5-D surface and then machine.
• You want a machine 10 widgets a second- Super-fast leads to super-cost for setup, ROI after millions are made.
• You can’t afford even one single mistake on any part. Technology has to be developed to make the process perfect.
• Extremely tight tolerances. For example: specifying a 200 micro hole to be +-1 micron on a 200 micron thick steel shim.

1. Requires Precise Inputs. For example: Liquid coolant or gas flow on machined parts to be very precise? 10 micron Polymer sheets to be within 0.25 thickness, else holes go out of spec.
2. Environment-Sensitive. For example: Even a 1 degree Centigrade change in room temperature throws off your beam or motion system, in turn affecting placement accuracy.
3. A different generation of metrology equipment might be required. For example: Exit and entrance quality specified on holes that are on a ledge, requiring Extra Long Working Distance microscope lenses. Or, you need to look for debris spread-area using dark-field lighting. Maybe an SEM is required to visualize the finished piece.
4. Monitoring of inputs and results, extensive record keeping, statistical analysis. This puts a heavy burden on the provider. It may be very important to you as a customer, but not for the provider unless they are paid to do this QC, process management and book-keeping.
5. Involvement of mature process managers with strong fundamentals in technical skill sets. AcmeLaser needs a manager with a lot of experience. This person is usually very busy with other things in the company, so unless you are willing to pay a lot, you can’t have a lot of the expert’s time.
6. Reliable and mature technicians and operators. AcmeLaser has to allocate the best of its staff to your project because it is too difficult and sensitive.
7. Excellent overall management of project. AcmeLaser doesn’t want its managers to micromanage- just get it running and move on to the next customer.
8. Willingness, appetite and ability to bear risk involved in spending resources on an untested process. You mean setting up this job is going to cost 10% of AcmeLaser’s annual budget?

The truth of the matter is that no service provider has every type of laser or motion system in-house. What for one is a specialized job might not be the same for another. When you send out a RFQ to several vendors and most of them respond, then you can be sure it is basically a simple project or it is a large enough project for providers to spend their resources to recoup their costs.

Executing Micromachining projects that are not run-of-the-mill type is difficult. Many companies turn down some of these projects, the rationale being that it is technically unfeasible or too expensive. Being unprofitable and few and far in between, they rightfully choose not to make it part of their core activities.

The knowledge base needed to execute many of these projects exists in disparate fields in the public domain, which has to be collated and used in an intelligent manner. If only the volumes justified the investment, more companies would be willing to give it a try.

Some Specialized Micromachining Projects

• True 3-D, true monolithic microparts without micro-joining
• Ultra small holes (micron and sub-micron) at high speeds.
• Motion calibration for precision Micromachining over large areas, done to traceable standards. Price becomes exponentially higher as you approach a +-1 micron error.