Cost of Microfocus X-ray Inspection System?

It is a $50.000 electron microscope - which sells in the hundreds per year - with a special detector, which sells in the tens per year.

Some of the extra $100,000 is just the cost of keeping that bit of the factory running spread over those tens of untis per year. At lot more of it is the cost of designing and debugging the add-on gear and getting it work with the electron microscope, which has to be recovered from each machine sold - after a few years, marketing will want to change the paint job and the model number, and engineering will have to redesign the electronics to add some irrelevant bell or whistle so that marketing can describe the new product as a developemnt of the old, so the design and evelopment expenditure isn't going to be spread over more than about a hundred machines.

-- Bill Sloman, Nijmegen (earlier employed by Cambridge Instruments on electron microscopes)

Your replay is regarded very useful. Many Thanks to you, Bill.

Why do you say it is an electron microscope?

The one I have seen for inspecting BGAs etc. seem to have a sealed x-ray tube which eliminates much of the complexity of an electron microscope i.e. vacuum pumps etc.

Here is an example:

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Microfocus - it implies focussing high voltage electrons into a very small spot, which is exactly what an electron microscope is about. I'm assuming that the X-ray inspection involved detecting element specific X-ray fluorescence created by the impact of relatively fast electrons - regular SEMs go up to about 30kV. If you want more than 100kV you need a much better vacuum around the electron gun which pushes the price of system up into another league.

--=20 Bill Sloman, Nijmegen (but in Paris for the next couple of days)

A lot of nonsense is being bandied about here. Why not just go to a real suppliers web page and find out all about it?

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And what makes you think that this is the microfocus that the OP was interested in?

I'm not saying that you are wrong, but I would like to know why you think you are right.

--=20 Bill Sloman, Nijmegen

The one I bought cost $150K used. Feinfocus is a brand name. But in the manual they talk about microfocus. The maximum useful magnification I could get was about 600X. I used it for analysis of electronic modules and components before they were depackaged for failure analysis.

The high voltage was variable from 40KV to 120KV or so. The maximum current was about 40 microamps. Why, because you didn't want to melt the target due to the small spot size. I think it was in 3 to 10 micron range so that good resolution could be obtained.

I haven't worked with it for over 5 years now, so my memory of the specs. maybe a little rusty.

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It could well be what the OP was after. Three to five microns might be good enough for looking at leads and bonding pads on packaged devices. If you want to look at the devices themselves, you need to go a lot finer, which is what you can do with electron microscopes set up to detect X-ray fluoresence - the spatial resolution is that of the electron beam, which can can be focussed into a spot of the order 10nm in diameter with a 30kV electron microscope, under favourable conditions.

Leaving the spot parked on one poit on the specimen can be destructive, but scanning the beam usually prevents permanent damage.

--=20 Bill Sloman, Nijmegen

Yes, I've used scanning electron microscopes for years doing imaging and EDS and the like. However, they don't work well when the device hasn't been depackaged yet.

The point of the radiography is to learn the structure of unknown devices/modules without destructively depackaging them. I've even made

3D radiographs to show how the wiring progresses through the packaging. Much useful information is acquired before the package is processed in any way, including electrically.

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Some useful information can be acquired about a part before you take off the packaging, but a great many problems are too localised to be visible until you have taken off the package and looked with a properly equipped electron microscope.

Modern system comes with ion-machining facilities to let you dig down through the layers of wiring and insulation above the silicon.

The voltage contrast system I worked on at Cambridge Instruments did a pretty fair job of imaging the waveforms on the top layer of wiring through the passivation, but it never did make it to production.

--=20 Bill Sloman, Nijmegen

Your right Al, A typical Microfocus x-ray tube could run in the tens of thousands of dollars depending on the focal spot size. Then add in all the mechanical, digital detector/PMT and Zoom, it goes to $150k. A comparison to Chip inspection is a fair comparision. Its not really a electron microscope. But a fine focus xray source.

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The distinction has to depend on peak currents - but the actual ize of the X-ray source is strictly limited by the electron current that you focus onto it, by exactly the same physics as limits the focal spot size in an electron microscope.

--=20 Bill Sloman, Nijmegen