Timeline for How is wafer dicing economical (for small ICs)?
Current License: CC BY-SA 4.0
13 events
| when toggle format | what | by | license | comment | |
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| Jul 21, 2020 at 1:29 | comment | added | Zac Faragher | You can make a (admittedly not very good) saw blade out of paper! youtube.com/watch?v=rYfkhdKcEiE | |
| Jul 19, 2020 at 20:38 | vote | accept | valerio_new | ||
| Jul 19, 2020 at 17:28 | comment | added | GNA | Silicon is a very cheap material. It's one of the most common elements found on our planet. The price of a wafer is dominated by the complex process of growing a monocrystaline block of silicon and purifying the silicon. As far as I know, the saw dust is just thrown out as garbage (unless there are dangerous substances on the wafer) | |
| Jul 19, 2020 at 5:20 | comment | added | Peter Green | Given the purity requirements of semiconductor processing, i'd imagine if it is recycled it has to go into a fairly early stage of the processing chain. | |
| Jul 18, 2020 at 18:13 | comment | added | Sim Son | @valerio_new From what I know, bare wavers are much cheaper than one might guess. Those smaller once (15cm) cost around 10 dollars, at least that's what my professor told me once. | |
| Jul 18, 2020 at 17:51 | comment | added | Hearth | From the numbers given in the initial question I was wondering if they bothered trying to recycle the lost silicon. But with such minuscule kerf widths, I imagine it wouldn't even be worth the effort. They might collect the dust into the next boule's melt or something but it wouldn't be a major part of it. At least I think not. | |
| Jul 18, 2020 at 8:25 | comment | added | GNA | Yes. I remebember for one ASIC I did, that the design rules specified, that each ASIC must have a 25 um tick dicing area around it. Which makes a total of 50 um between two asics. However, I do not know what kind of a saw was used in that particular case. Probably around 30 um or so. Dicing saws are very precisely made. Also the height of the saw blade is very critical. The wafer is glued to a blue tape and then diced. The wafer saw has to cut through the entire wafer but must not cut through the foil on the back or everything would fall apart. | |
| Jul 18, 2020 at 8:12 | comment | added | SomeoneSomewhereSupportsMonica | I suspect that the kerf width/blade thickness is somewhat smaller than the 'street' that the blade cuts along - there is a section of dead space left on either side to account for tracking issues and possible damage. | |
| Jul 18, 2020 at 8:08 | comment | added | GNA | This is just something I quickly pulled out: disco.co.jp/eg/products/catalog/pdf/zh05.pdf Look at the last page. There is a parameter called kerf width. In this saw series it can go down to 17.5 um | |
| Jul 18, 2020 at 7:43 | comment | added | valerio_new | A comment above links a paper in which a 50um blade is presented as a big innovation from the 85um blade. There's no date on the paper, but it cites another paper from 2014, so it is at least from 2014. Do you have any source on the blade thickness you are citing? (BTW thanks for the answer) | |
| Jul 17, 2020 at 23:04 | comment | added | Dan | Woah, those things must have some pretty cool engineering inside of them. | |
| Jul 17, 2020 at 22:06 | history | edited | GNA | CC BY-SA 4.0 |
added 181 characters in body
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| Jul 17, 2020 at 22:00 | history | answered | GNA | CC BY-SA 4.0 |