| ▲ | kens 7 days ago |
| Author here for all your CT scanning questions :-) |
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| ▲ | johnklos 7 days ago | parent | next [-] |
| This isn't about CT scanning, but about the chip itself. Since the bond wires are just hanging out in air, does this mean that a chip like this could be ruined by dropping it which might cause the bond wires to move enough to short something? Thanks for all your hard work! |
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| ▲ | generuso 7 days ago | parent | next [-] | | If the chip is subjected to a few thousand g's of shock the wires can bend and short. This failure mode is quite low on the list among others, but it is something that people did investigate. For example: "Swing Touch Risk Assessment of Bonding Wires in High-Density Package Under Mechanical Shock Condition"
https://asmedigitalcollection.asme.org/electronicpackaging/a... | |
| ▲ | besserwisser 6 days ago | parent | prev | next [-] | | Yes, that can be a problem. Story from one of my professors who worked on instrumentation and telemetry for a defense lab. They built a data recorder for artillery shells. In the early "flight" tests, the recorders failed and nobody could figure out why. They worked before and after. Then someone realized the high acceleration bent some of the bond wires in the chips, causing them to touch and short. The fix was surprisingly simple: make sure all chips face top down. | |
| ▲ | userbinator 7 days ago | parent | prev [-] | | I'm not an expert in this area but I'd expect that the bond wires' mass is low enough relative to their stiffness that any shock sufficient to bend them would also shatter the ceramic package. |
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| ▲ | s1110 7 days ago | parent | prev | next [-] |
| Genuine question: the website doesn't work in Russia. Did you restrict the access or is it my ISP doing that? Someone tries to prevent me from studying of very niche info on ancient Intel CPUs. Thanks! P.S. Big fan of your work! |
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| ▲ | kkaske 7 days ago | parent | next [-] | | I did find that, while running a financial startup, I was able to significantly reduce attacks on the server by disabling access from Russia and China. Not saying that's happening here, just my experience. That was a while ago so I'm sure things have changed since then. | | |
| ▲ | red75prime 7 days ago | parent | next [-] | | That is it was more financially effective to block an entire country, than analyzing attack patterns and blocking by ASNs or IP-ranges. Correct? | | |
| ▲ | astrange 7 days ago | parent | next [-] | | Startups don't have enough free time to analyze individual ASNs, because they don't have enough people for that. That and financial businesses usually don't operate outside their host country anyway. Though you do want your customers to see their accounts when they're traveling. | |
| ▲ | pyuser583 7 days ago | parent | prev [-] | | Yes. Multiple countries. In all fairness, this isn’t a good use of that technique. But most websites are of no interest outside a handful of countries. |
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| ▲ | s1110 7 days ago | parent | prev [-] | | Thanks for your reply! I hope this is the real reason of blocking. If that's not the case, that's at least not effective. Less effective than idk placing a banner in the header or whatever. I mean I eventually read the article. Sorry for that. But we're at "Hacker News", sporting hackers ethics, aren't we? | | |
| ▲ | inferiorhuman 7 days ago | parent [-] | | Opposing the invasion of Ukraine and the biggest existential threat Europe's faced in a couple generations seems pretty ethical to me. | | |
| ▲ | pyuser583 7 days ago | parent | next [-] | | We should be jamming American media down Russias throats like we did during the Cold War. | | |
| ▲ | wood_spirit 7 days ago | parent [-] | | Radio Free Europe and Radio Liberty were one of the very first things that the Trump presidency stopped. |
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| ▲ | drysine 7 days ago | parent | prev | next [-] | | By preventing some computer history enthusiast in Russia from reading an article on a processor from 1985? Really? | | |
| ▲ | inferiorhuman 7 days ago | parent [-] | | [flagged] | | |
| ▲ | drysine 6 days ago | parent [-] | | >It's not the author's responsibility to shield the Russian population from the consequences of war. "It's not the author's responsibility to shield the Russian population from himself blocking access to Russians"? | | |
| ▲ | inferiorhuman 6 days ago | parent | next [-] | | A quick look at your comment history reveals a relatively new account primarily used for shouting down comments that aren't explicitly pro-Russia. With that in mind I'd say it's safe to assume two things: 1.) You're not commenting in good faith 2.) The author's presumed actions were quite effective in spite of your disbelief. | |
| ▲ | inferiorhuman 6 days ago | parent | prev [-] | | [flagged] |
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| ▲ | holoduke 7 days ago | parent | prev [-] | | [flagged] |
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| ▲ | tgv 7 days ago | parent | prev | next [-] | | It could be this: https://blog.cloudflare.com/russian-internet-users-are-unabl... | |
| ▲ | vodkadin 7 days ago | parent | prev | next [-] | | Some smaller sites ban ips from countries that continually try to hack into your server or just make a ton of requests, it happens to be that traffic is often from Russia and China. Could just be that. | | |
| ▲ | tjwebbnorfolk 7 days ago | parent [-] | | I block Russia, China, and Iran from my sites. They represent 0% of the revenue, and 99% of the login attempts. | | |
| ▲ | mavamaarten 6 days ago | parent [-] | | Yeah. In the same vein I also don't distribute my app in the Play Store in certain countries. I realize it completely sucks for them, but it's purely a business decision. Certain countries are just very vocal in terms of negative reviews, simply swap 5 star and 1 stars due to cultural differences, and also bring in almost zero revenue. The net result of distributing in these countries is literally negative: they hurt my ratings and reviews and don't make up for that in terms of money. |
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| ▲ | grishka 6 days ago | parent | prev | next [-] | | Probably your ISP, or more precisely, the ТСПУ box they were required to install. You can use this tool to test your connectivity to these hosting providers that the government dislikes: https://hyperion-cs.github.io/dpi-checkers/ru/tcp-16-20/ Ken himself did block access to his website from Russia for a while after 24/02/2022, but right now it loads for me after a CF captcha. | |
| ▲ | userbinator 7 days ago | parent | prev | next [-] | | One word: VPN | | | |
| ▲ | vardump 7 days ago | parent | prev | next [-] | | [flagged] | | |
| ▲ | userbinator 7 days ago | parent | next [-] | | I'm against war but it just says nothing more than stupid virtue-signaling when you do stuff like this. What's ironic is that the ones doing this crap are usually the first to cry about internet censorship. | | |
| ▲ | xpe 7 days ago | parent | next [-] | | > ... nothing more than stupid virtue-signaling ... The commenter don't know this with certainty. It is a rather uncharitable assumption. It is hard to know what is inside the head of another person. | |
| ▲ | tom_ 7 days ago | parent | prev | next [-] | | If the people providing the information want to block you from reading it, that does rather feel like their prerogative. | |
| ▲ | vardump 7 days ago | parent | prev | next [-] | | This has nothing to do with "virtue-signaling". Russia's actions have been extremely evil, so it's only natural it generates dislike, even hate. That's how we humans are. Same happened to the Germans during and after World War II. | | |
| ▲ | userbinator 7 days ago | parent [-] | | What the government and its leadership does is very different from civilians (which may not even have the power to change anything). |
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| ▲ | CogitoCogito 6 days ago | parent | prev | next [-] | | > What's ironic is that the ones doing this crap are usually the first to cry about internet censorship. I believe most people against internet censorship are against _government_ censorship. I fall into that camp. I don't support government censorship of the internet, but I have no problem if individual website operators decide they don't want to serve a certain country. | |
| ▲ | wat10000 7 days ago | parent | prev [-] | | Imagine thinking it’s bad to signal virtue. It’s not censorship when the author is the one limiting who can see it. And what’s your basis for saying these people are the first to cry about internet censorship? Have you actually seen the same people doing this or are you just imagining it to be true? | | |
| ▲ | encom 7 days ago | parent [-] | | Virtue signaling is not the same as being virtuous. It's an empty, zero effort, gesture that contributes nothing of real value or meaning. Like changing your profile picture or posting a trending hashtag. | | |
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| ▲ | orbital-decay 7 days ago | parent | prev | next [-] | | It's a kneejerk reaction and a dumb way to oppose anything. People couldn't care less about some site becoming unavailable. What really happens when the site goes down in a way like that is it removes its own presence from the minds. Doing that is basically blocking yourself, instead of blocking "them". One less voice to hear. | | |
| ▲ | inferiorhuman 7 days ago | parent [-] | | People couldn't care less about some site becoming unavailable.
If that were true, why complain about it on HN? | | |
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| ▲ | Mountain_Skies 7 days ago | parent | prev [-] | | Collective punishment is considered abhorrent in much of the world. It's acceptable in places that you'd probably not want to live or to change our societies into. | | |
| ▲ | vardump 7 days ago | parent [-] | | I don't think you can consider a website ban as collective punishment. |
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| ▲ | orbital-decay 7 days ago | parent | prev | next [-] | | It is your ISP. (don't ask me how I know but please research this before posting) | |
| ▲ | justsomehnguy 6 days ago | parent | prev [-] | | Because the author is the opportunistic racist: > kens on April 10, 2022 > Are you trying to access from Russia? Russia is currently blocked. https://news.ycombinator.com/item?id=30974444 > kens on Dec 3, 2022 > Unfortunately there are also many people in Ukraine who didn't personally do anything to deserve what's happening. Consider the country filter a small reminder of the ongoing war and a suggestion that you might find better opportunities outside Russia. https://news.ycombinator.com/item?id=33846782 Yet he doesn't consider to 'find better opportunities outside of the USA' despite the actions of the USA government in the last 30 years. |
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| ▲ | rylando 7 days ago | parent | prev | next [-] |
| What kVp/mAs do you use for this? How are you avoiding the artifacts seen from medical imaging? Curious, in school for CT in the medical field. |
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| ▲ | kens 7 days ago | parent [-] | | Lumafield does all the work; I just get the images :-)
The data says 130 kV, 123µA. The whole scan took 21 hours: 1200 projections of 60 seconds each. I assume that they avoid artifacts by using a whole lot more radiation than medical imaging would permit. | | |
| ▲ | rylando 6 days ago | parent [-] | | I’m assuming each image was taken with 123 microamperes? Or is that total dosage over the 21 hours? If it’s total that’s much less than medical dosage, but if it’s per image that’s a lot more! Thanks for the info, how interesting! (for those who don’t know, mAs = mA • seconds = milliampere seconds. It’s how Radiographers measure how much x-ray photos are being produced by the tungsten filament in an X-ray tube. kVp is kiloVoltage potential and it’s how we measure the speed and thus the penetration power of the X-rays. 130kvp is slightly more than the 120kvp used for an avg human chest radiograph) | | |
| ▲ | kens 5 days ago | parent | next [-] | | I asked Jon Bruner at Lumafield for details: The scan was performed on our Neptune Microfocus scanner, configured with a 130 kV source. Current varies on this source depending on scan settings; in this case 123 µA. Each voxel in this scan is 12.8 microns; for smaller parts that we're able to move even closer to the X-ray source we can achieve 3-6 micron voxels. Compared to medical CT scans, this is much higher resolution--medical CT scans have voxels on the order of 0.5 to 1 mm! This is possible because we're able to apply much higher X-ray doses in industrial scans. Medical CT scans are typically on the order of 120 kV, at higher current but for much less time--perhaps a few seconds compared with minutes to hours for an industrial CT scan. | |
| ▲ | fecal_henge 6 days ago | parent | prev [-] | | Any rational argument to use mAs instead of mC? |
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| ▲ | imoverclocked 7 days ago | parent | prev | next [-] |
| Does it look like the almost connected pins could have been purposely severed during production? ie: could they have been connected and then using a calculated pulse of power, disconnected? |
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| ▲ | kens 7 days ago | parent [-] | | If they installed wire bonds and removed them, there would be visible remnants on the die, which aren't there. |
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| ▲ | loa_in_ 7 days ago | parent | prev | next [-] |
| Is the CPU destroyed by the process or did you reassemble this particular specimen? |
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| ▲ | kens 7 days ago | parent | next [-] | | I took the metal lid off the chip to improve the scan quality. If I had left the chip intact, it would probably be fine. (I assume the X-ray levels are low enough to avoid damage, but I haven't confirmed that.) | | |
| ▲ | wkat4242 7 days ago | parent [-] | | Also 386s are very resistant to radiation, I believe they still use them on the ISS for that reason (a radiation-hardened version but still) |
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| ▲ | 7 days ago | parent | prev [-] | | [deleted] |
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| ▲ | bunabhucan 7 days ago | parent | prev | next [-] |
| What is the last node/cpu that had the smallest features visible at optical microscope scales? |
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| ▲ | rts_cts 7 days ago | parent [-] | | With a good scope we could inspect 0.35um chips just fine. I honestly didn't look at die photos much after that until we started getting SEM images of 32nm and smaller chips |
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| ▲ | 7 days ago | parent | prev | next [-] |
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| ▲ | TZubiri 7 days ago | parent | prev | next [-] |
| What CT scanner was used? The images are surprisingly detailed for something so small, while we are used to coarser scales of human anatomy. |
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| ▲ | kens 7 days ago | parent [-] | | It's a Lumafield scanner, but I don't know the specific model. |
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| ▲ | OptionOfT 7 days ago | parent | prev [-] |
| What is your CPU's yearly deductible? |
