The secret is that 180nm nodes are so legacy that they have a ton of spare cycles for educational and apparently now hobbyists. Lots of various businesses are offering services now that sell the ancient 180nm node.
Overall, the plan is much like OSHPark. You build a die that can be paired up with all of the other customers for a run. If say 300 wafers are made with 1000 different designs on it, everyone gets 300ish chips (before errors) and 1000 designers are happy.
*Made up numbers of course. I'm not in the business.
If say 300 wafers are made with 1000 different designs on it, everyone gets 300ish chips
That's not how it works. The same pattern, called a "reticule" [1] is duplicated 300 times over the wafer. One wafer gives you 300 copies of whatever set of dies fit into one reticule.
[1] it's to do with the size of the optical/UV lenses that are used in mask-making
That's true but they keep upping the capabilities of what the designer can do at 180nm. Based on the wait times for my jobs, there's not a lot of spare cycles, at least at the foundries I use.
Its more likely that 180nm fabs are idling so much that they've made the decision to close. There's only so low that the prices can go before these businesses don't think its worth staying in business anymore.
I've heard that over the long term, 28nm should theoretically be the "long term cost-efficient node". The 65nm and other nodes are all cheaper in practice because these factories are fully paid off by now.
It was something about 300mm wafers and overall tooling being shared with 28nm with the latest nodes + overall investments. While 200mm likely will be shutdown over the long term (but 200mm wafers will remain the cheapest solution in the short term).
So under these expectations, I'd say that 180nm, 65nm, and other old nodes will slowly shut down as everyone moves to the long-term most efficient node. Still, having the oldest nodes stay open for the educational / hobbyist / experimental R&D for some commerical companies makes sense. Especially since the wafers are smaller and thus overall runs can be smaller.
Comments
The secret is that 180nm nodes are so legacy that they have a ton of spare cycles for educational and apparently now hobbyists. Lots of various businesses are offering services now that sell the ancient 180nm node.
Overall, the plan is much like OSHPark. You build a die that can be paired up with all of the other customers for a run. If say 300 wafers are made with 1000 different designs on it, everyone gets 300ish chips (before errors) and 1000 designers are happy.
*Made up numbers of course. I'm not in the business.
That's not how it works. The same pattern, called a "reticule" [1] is duplicated 300 times over the wafer. One wafer gives you 300 copies of whatever set of dies fit into one reticule.
[1] it's to do with the size of the optical/UV lenses that are used in mask-making
That's true but they keep upping the capabilities of what the designer can do at 180nm. Based on the wait times for my jobs, there's not a lot of spare cycles, at least at the foundries I use.
180nm is declining as far as I'm aware.
Its more likely that 180nm fabs are idling so much that they've made the decision to close. There's only so low that the prices can go before these businesses don't think its worth staying in business anymore.
I've heard that over the long term, 28nm should theoretically be the "long term cost-efficient node". The 65nm and other nodes are all cheaper in practice because these factories are fully paid off by now.
It was something about 300mm wafers and overall tooling being shared with 28nm with the latest nodes + overall investments. While 200mm likely will be shutdown over the long term (but 200mm wafers will remain the cheapest solution in the short term).
So under these expectations, I'd say that 180nm, 65nm, and other old nodes will slowly shut down as everyone moves to the long-term most efficient node. Still, having the oldest nodes stay open for the educational / hobbyist / experimental R&D for some commerical companies makes sense. Especially since the wafers are smaller and thus overall runs can be smaller.