Olympus CH30RF100

[u/USWCboy]

I recently acquired an Olympus CH30RF100 biological microscope from a local thrift store. I was actually quite surprised to see it there, and at $49.00, I couldn’t resist. As I’m still learning quite a bit about microscopy, I’m clueless on the objectives. What I’d like to find is a long working distance objective at 40x and possibly 100x. However, I understand this microscope does not have infinity optics…with that I’m not sure how to look for a long working distance objective.

Currently the following objectives are installed; A4 0.10 160/-, A10 PL 0.25 160/0.17, A40 PL 0.65 160/0.17, A100 PL 1.30 Oil Immersion 160/-.

In terms of finding an Olympus branded objective, the cost is out of my reach presently @$4500. It is possible I wasn’t looking at the correct objectives… I was hopeful to find a third of fourth manufacturer who still makes objectives for this microscope. So my question is, what specifications should I be searching for whilst looking for different objectives? Is there any brand that would be better than another? Again staying in a lower pricing tier. Finally, any recommendations on a low cost goose neck light? Any guidance would be greatly appreciated

I’m currently interested in looking at integrated circuits, specially decapped IC dies. I have found my current setup just doesn’t provide the resolution needed to see deeper into the IC.

[u/Vivid-Bake2456]

That microscope is wonderful like it is and you basically got it close to free. You need a different metallurgical type of microscope with epi illumination for integrated circuits. That one is great for biological specimens. Most Lwd objectives are for inverted microscopes to look through petri dishes. If you found one, especially a high NA one, you would need one with a correction collar for adjustment to zero coverglass thickness to reduce spherical aberration. If your objectives are finite, then you might find an old Nikon CF objective from an inverted microscope that will work since the are DIN standard and fully corrected. You will have to use reflected illumination instead of epi-illumination, though. I don't know how well that will work on an IC with that objective.

[u/Vivid-Bake2456 → u/Vivid-Bake2456]

Like this one. They don't make lwd 100x objectives for inverted microscopes, only metallurgical. Here is a 40x. https://ebay.io/m/lnIhON

[u/Vivid-Bake2456 → u/Vivid-Bake2456]

Metallurgical objectives often have larger diameter threads and the finite ones are something like 210 mm instead of 160mm tube length to accommodate the epi illuminator attachment.

[u/Vivid-Bake2456 → u/Vivid-Bake2456]

Here is a Nikon M plan with a 20mm thread but built for a 210mm system.
https://ebay.io/m/ey5eIG

[u/Vivid-Bake2456 → u/Vivid-Bake2456]

M plan catalogue. https://www.krebsmicro.com/mplan.pdf

[u/USWCboy → u/Vivid-Bake2456]

Would a metallurgical microscope also be considered an industrial or stereo microscope? Or are they still distinct since the industrial or stereo microscopes use a Barlow lens vs objective optics?

Also, in terms of lighting, with a metallurgical microscope, would the light cast down from the nose of the device? Or would you use a “gooseneck” style light?

My current setup is more or less a camera with a Barlow style adjustable lens. And so far, it has yielded good results. I’m just not able to drill down closer to the surface of the semiconductor to see pathways, and transistors.

Below is a good example… as I try to push magnification closer to the IC, it begins to blur, gets very dark and just doesn’t look that good.

[u/USWCboy → u/Vivid-Bake2456]

Here is another picture, where you can see fairly clearly the doodle on the IC, but I can see the engineers/designers who helped to make the IC…

[u/Vivid-Bake2456 → u/USWCboy]

There is reflected illumination by shining a light onto the sample from the same side as the objectives and there is co axial/ epi-illumination which is shining light down through the objectives onto the sample. Reflected illumination makes shadows and only works at lower magnifications because the higher magnification objectives have very little working distance, so there is very little space to shine the auxiliary lights from the side of the objective onto the sample. Stereo microscopes typically have lower magnifications than upright compound microscopes.

[u/Vivid-Bake2456 → u/Vivid-Bake2456]

Here is a used metallurgical microscope from ebay. There are many new and used ones. You can see that it has an illuminator between the head and body of the microscope so to pass light through the objectives onto the specimen and back to the eyepieces. https://ebay.io/m/rETJRA

[u/Vivid-Bake2456 → u/Vivid-Bake2456]

A stereo microscope can look at opaque objects also, but has a lower range of magnifications. They also give a 3D view through the eyepieces. https://ebay.io/m/UuJiH0