Important attributes of an X ray inspection system - Page 1
Forum section: electronics / general

author: IconicPCB
author_rank: Super Contributor
timestamp: December 12, 2022, 07:43:24 am
content: I am considering getting an Xray inspection unit.I am worried the unit performance might be a bit mediocre as it employs a source with a 100um target ( source of X ray radiation) at 60KV.Any opinions and comments?

author: hanakp
author_rank: Regular Contributor
timestamp: December 28, 2022, 01:24:51 pm
content: I'm personally using Phoenix X-Ray Micromex 180 DXR-HD in my workplace, so I can speak from experience.-If the machine's maximum acceleration voltage is 60 kV, don't even bother with it, the X-rays won't be able to penetrate modern 8+ layer PCBs. Well, they will, but SNR will be low and you will get very grainy image. And you won't be able to see anything under bigger components like electrolytics or inductors.-Tube current (and power in W) is another important parameter that affects image quality. Basically, it defines how many X-ray photons get generated per second. For general work, I'm using 80 kV/80 uA (6.4 W) to get best results. In multilayer PCBs, I have to go to 120 kV/80 uA or even 120 kV/120 uA (14.4 W).-But there is caveat: the machine spatial resolution depends on how tiny spot you create on x-ray tube target. Basically, it's the same mechanism as in pinhole camera - the sharper the hole, the sharper the resulting image. But in the real world, the higher the electron beam power, the larger the spot becomes and resolution suffers. I have a set of images that showcase it. If "your" machine has 0.1 mm spot, it's not actually bad, but I'll bet my pants it's so small only on the lowest tube power range.-All this stuff also strongly depends on the construction of the tube (transmission vs. reflection target) and the x-ray detector (scintillator vs. direct conversion).So my advice is: take the most massive samples of what you want to x-ray, personally go to the distributor's showroom and see the results for yourself. That way, you will also see how (im)practical the machine is to operate, how quickly the CNC table(s) move, how long it takes to acquire the final image etc. Trust me, these machines are expensive and the trip will be well worth it.

author: IconicPCB
author_rank: Super Contributor
timestamp: December 28, 2022, 10:43:59 pm
content: Hello Hanakp ,Thanks for taking the time to respond.I saw this product on ebay and here is the product description heading:X-Ray Inspection machine with image PC 100um focus spot Toshiba tube AJ-1600AJ-1600 is the product model number.This is the link to ebay pagehttps://www.ebay.com/itm/134069448695?_trkparms=amclksrc%3DITM%26aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20180816085401%26meid%3Def11cee7de984d38b15e89edf74702a1%26pid%3D100970%26rk%3D3%26rkt%3D3%26sd%3D285038147300%26itm%3D134069448695%26pmt%3D0%26noa%3D1%26pg%3D2380057&_trksid=p2380057.c100970.m5481&_trkparms=pageci%3A2d3120c4-86ff-11ed-a5f1-9e747ca8c75f%7Cparentrq%3A5adb62161850a826daad6ba9fff3fd93%7Ciid%3A1It seems to be a very rudimentary box , the question is just how utilitarian is it?Please comment.I have no links to the advertiser or equipment manufacturer.

author: hanakp
author_rank: Regular Contributor
timestamp: December 30, 2022, 12:26:53 am
content: Let me start with this: in all western countries, you can't legally buy and run an x-ray machine just because you like it. It has to be certified by local nuclear safety agency and at the very least, you need to notify the agency that you got one. If you're living in Australia, it's ARPANSA:https://www.arpansa.gov.au/So as the very first step, you need to contact them and ask them if that particular model is cleared for use in your country. And if so, what are the conditions for its use. For example, "my" x-ray machine has to be checked for radiation leakage every year. That has to be done by a qualified serviceman and with a calibrated dosimeter. And of course, "my" machine can be operated only by people who were provably instructed about dangers of x-ray exposure and all the safety mechanisms the machines has to prevent it.As for "your" machine, it seems dodgy to say the least. It probably works, but... are you sure you want to risk your health and life with it? This is 6 Watt, continuous hard x-ray source, not a toy. They say it's shielded inside (which is good) but I don't understand why they offer the remote trigger? It's almost like they don't they don't trust the shielding is good enough... Well, just ask ARPANSA, I'm sure they also run a database of dangerous machines.Apart from that, they provide no sample x-ray photos, which is also highly suspect. From practical standpoint, the machine has no CNC manipulator to move the scanned object. That's fine if you scan one known area on many identical components, but not if you're trying to find where the problem actually is.

author: KE5FX
author_rank: Super Contributor
timestamp: December 30, 2022, 01:28:26 am
content: Quote from: hanakp on December 28, 2022, 01:24:51 pmThat has more to do with the image sensor than with the voltage. 35 kV yields excellent results with a Faxitron, as any number of shots posted in the X-ray threads on here will attest.8 layers is indeed about the limit, though, at 35 kV. 60 kV would have no problem going through any PCB you are likely to encounter...ifthe sensor can hold up its end of the bargain.Of course any higher-end machine will be optimized for real-time viewing, which could be the biggest factor of all with your equipment, and not an issue with this one. To look at an 8-layer board at 35 kV with the Faxitron, the exposure time needs to be more like 10-15 seconds.Quote from: hanakp on December 30, 2022, 12:26:53 amYou also can't legally drive over 35 MPH (56 kPH) on the road going past my house, but that doesn't seem to stop anyone.That said, the combination of "60 kVp," "China" and "eBay" would make me take radiation survey practices very seriously even if they weren't legal requirements. $8200 US isn't a bad price for what you're getting, but leave a few hundred dollars in the budget for a Geiger counter.QuoteThey provide several sample photos but you have to hunt for them. Results seem fine for everyday inspection and reverse-engineering work. A manipulator arm would be great, of course, but very unrealistic to expect at this price point.