Stefan Motyka is a Senior Product Manager at Leica Microsystems in Wetzlar. In an interview with technology journalist Heinz-Joachim Imlau, he explains further details about the microscope that, in his words, make the DM8000/DM12000 a "race car" among inspection microscopes.
Mr. Motyka, why is the DM8000/12000 microscope so fast?
The speed is simply due to the fact that both the DM8000 and the DM12000 microscopes - the latter only has a larger table - offer a four times bigger overview of the sample compared to conventional microscopes. The integrated macro mode is responsible for this capability. When using the usual objective lenses with a significantly higher magnification factor, the user often can't see the forest for the trees. With the DM8000/12000, he immediately sees in macro mode the "clearing" which makes all the difference, changes the lens, and is immediately " in the middle ". This mode dramatically increases sample throughput.
Concerning users: It is an open secret that in production plants for electronic components, people are often the weakest link in the quality chain. Especially when working in three shifts and making the highest demands on component quality around the clock. How does Leica Microsystems meet this challenge?
We at Leica Microsystems understand well the problem. It is caused, on the one hand, by a lack of highly qualified personnel and, on the other hand, by time and cost pressure. We have designed our DM8000/12000 microscope in such a way so that operating errors or notorious "tinkering" are ruled out. Depending on the user's qualifications, critical configurations of the microscope are either excluded or enabled by programmable "user levels". In addition, there is the mechanical and electrical stability which does not get reduced even after continuous use, as well as the well thought out ergonomics.
Microscopic component inspection is still a subjective field of activity, despite all the progress made for example in Artificial Intelligence (AI). How do you make sure that even an inexperienced user makes no or very few misinterpretations of the results?
The most important factor in the assessment of components is unambiguity. The typical user in this area compares printed microscope images - the reference images - with what he sees in the eyepiece. With a conventional microscope using halogen illumination, the color temperature changes after just a few hundred hours. For example, the user sees reddish shimmering solder joints in the eyepiece which, according to the reference images, should actually be white. To prevent this from happening, the halogen lamps have to be replaced regularly.
And Leica Microsystems uses Light-Emitting Diodes (LEDs) instead?
Correct, namely calibrated LEDs with a standardized color temperature of 3800 K and a service life of more than 25,000 hours. If the reference images were also taken with this color temperature, the results can be easily interpreted, subjective errors are minimized, and throughput increased.
For a light microscope, the DM8000/12000 offers astonishingly sharp, detailed images which are normally only seen with electron microscopes. Has Leica Microsystems outwitted physical laws?
You could say so. It is well known that not all light is the same: the shorter the wavelength, the more details can be imaged. We have simply integrated a short wavelength light source into the DM8000/12000 system that generates invisible light, namely in the UV (ultraviolet) range. For safety, no UV light can be seen through the eyepieces, but an image is visible only on the monitor. Simply put, a special digital camera records the reflection of the UV light from the sample and converts it into visible monitor images.
Even 3D images could be generated in this way?
True 3D of course not, as we only have one light ray path available. Plastic images would be the better expression. For this we use OVU, the "oblique UV", an oblique illumination with UV light. Thanks to the higher depth of field of the UV range, very meaningful images are produced - which in turn increases clarity and unambiguity and then throughput too.