3 ms·

The biggest skeleton in the room was barely mentioned once. Chip shortage, or, better say, capacity shortage for affordable nodes been there for 5-7 years, and

The biggest skeleton in the room was barely mentioned once. Chip shortage, or, better say, capacity shortage for affordable nodes been there for 5-7 years, and nobody really gave it much notice. Lead times for average 180nm project were 12 months+ for last 5 years. There is still a stratospheric gap in between "common man fab service," and the realm of multi-million dollar semi companies, who can afford service on relatively new, (and not decades old) equipment. All significant chips which went into shortage were using that "common man fab process" on eighties, and nineties era equipment.

bsder 5y ago
> All significant chips which went into shortage were using that "common man fab process" on eighties, and nineties era equipment. I don't think I agree with that. A LOT of small microcontrollers went into allocation and they were on 120nm, 90nm, and 65nm processes. However, I do agree that there really was a shortage even before Covid and nobody cared. Effectively--nobody builds a line for an older node, ever. And there has been a lot of consolidation and sales of facilities such that very few people have been building fabs below 90nm. The number of fabs built in the 2010's that aren't TSMC, Intel, or Samsung is pretty minimal.
- raverbashing 5y ago
  Now that the nm race is getting to a halt, I think that maybe there's a point of picking an older node and focusing on that for volume parts 65nm? 90nm? 180nm? I'd argue that the processes can be improved and cost can probably come down compared to the older machines. I'm old enough to remember when 180nm chips were the fastest ones.
  - nwiswell 5y ago
    > 65nm? 90nm? 180nm? I'd argue that the processes can be improved and cost can probably come down compared to the older machines. This is really dubious for two reasons. First, you can do a die shrink and fit many, many more equivalent chips onto a single wafer at a modern node. This is somewhat mitigated by the high cost of mask sets at modern nodes -- but there's just no way it would ever make economic sense to build capacity at 180nm. Second, the equipment for old nodes is not made anymore. It's cheap, but that's only because there's ample supply on the secondary market. If fabs began to get restarted in earnest at old nodes, that supply would quickly evaporate. Then you would have to buy modern (expensive!) equipment -- at which point why not take advantage of its full potential? Wafer throughput is the same regardless of whether you're making 100 chips per wafer at 180nm or 10,000 at 22nm.
    - baybal2 5y ago
      Do you know how much modern masksets cost? More than a MILLION DOLLARS for a set, and completely ridiculous sums for anything <28nm. So, if your market is <1M dies a year, you have to price your chip >$1 just to break even. And in the car chip market, even 1M dies is a giant amount. Car market was all about decades old chips, made to stringent automotive specs, manufactured in tiny batches, and sold on long term contracts at sub-10 cent per packaged, tested, and binned die (and low bin chips were usually simply thrown away.)
      - nwiswell 5y ago
        > So, if your market is <1M dies a year, you have to price your chip >$1 just to break even. And in the car chip market, even 1M dies is a giant amount. No, this is not the case. If you have a small run, the foundry will "consolidate" your chip with other customers to make a single mask. This makes sense all around, since the foundry would rather not have to deal with a mask set that has only a few wafer starts anyway.
        baybal2 5y ago
        You don't make commercial chips on a shuttle run. If you sit on the same mask as somebody else, you forsake all the flexibility, and you are limited to fabs with own mask shops — just taking your masks, and moving to another fab with them is near impossible. Asking the fab to make just any process tweaks is similarly impossible.
        deleted 5y ago
        [deleted]
        nwiswell 5y ago
        I've never heard of a customer getting process tweaks for a one million die run, but then again I've got no experience with legacy fabs. Certainly the 14nm fab that Intel promised lately[1] for automotive demand would not entertain that sort of thing. [1] https://www.electronicdesign.com/markets/automotive/article/21174750/electronic-design-intel-to-commit-foundry-capacity-for-chipstarved-auto-industry https://www.electronicdesign.com/markets/automotive/article/...
  - namibj 5y ago
    Especially considering that nowadays 180nm is accessible (if necessary, via double-patterning/immersion 405nm to please the DLP's aluminium mirrors) from maskless steppers, which can improve turn-around times by eliminating shared-mask aggregation delays and allows for cheap experimentation (no more minimum order quantity). This is even more significant when one remembers that maskless steppers already have to do stitching for everything significantly more complex than an opamp, and the per-area price scales up to full monolithic wafers without the tiling constrainst Cerebras has to adhere to.
- fmajid 5y ago
  > Effectively--nobody builds a line for an older node, ever. UMC, Taiwan's No. 2 fab, offered to build a new 64nm line in an existing fab in exchange for a $1B firm order commitment. Nobody bit, they preferred instead to lean on the Biden administration to pressure the Taiwanese government to allow them to skip the line. A new fab on old process nodes is not viable if it has to compete against fully amortized hand-me-down fabs that used to be cutting-edge 10-20 years ago.

bsder 5y ago

> All significant chips which went into shortage were using that "common man fab process" on eighties, and nineties era equipment. I don't think I agree with that. A LOT of small microcontrollers went into allocation and they were on 120nm, 90nm, and 65nm processes. However, I do agree that there really was a shortage even before Covid and nobody cared. Effectively--nobody builds a line for an older node, ever. And there has been a lot of consolidation and sales of facilities such that very few people have been building fabs below 90nm. The number of fabs built in the 2010's that aren't TSMC, Intel, or Samsung is pretty minimal.

raverbashing 5y ago
Now that the nm race is getting to a halt, I think that maybe there's a point of picking an older node and focusing on that for volume parts 65nm? 90nm? 180nm? I'd argue that the processes can be improved and cost can probably come down compared to the older machines. I'm old enough to remember when 180nm chips were the fastest ones.
- nwiswell 5y ago
  > 65nm? 90nm? 180nm? I'd argue that the processes can be improved and cost can probably come down compared to the older machines. This is really dubious for two reasons. First, you can do a die shrink and fit many, many more equivalent chips onto a single wafer at a modern node. This is somewhat mitigated by the high cost of mask sets at modern nodes -- but there's just no way it would ever make economic sense to build capacity at 180nm. Second, the equipment for old nodes is not made anymore. It's cheap, but that's only because there's ample supply on the secondary market. If fabs began to get restarted in earnest at old nodes, that supply would quickly evaporate. Then you would have to buy modern (expensive!) equipment -- at which point why not take advantage of its full potential? Wafer throughput is the same regardless of whether you're making 100 chips per wafer at 180nm or 10,000 at 22nm.
  - baybal2 5y ago
    Do you know how much modern masksets cost? More than a MILLION DOLLARS for a set, and completely ridiculous sums for anything <28nm. So, if your market is <1M dies a year, you have to price your chip >$1 just to break even. And in the car chip market, even 1M dies is a giant amount. Car market was all about decades old chips, made to stringent automotive specs, manufactured in tiny batches, and sold on long term contracts at sub-10 cent per packaged, tested, and binned die (and low bin chips were usually simply thrown away.)
    - nwiswell 5y ago
      > So, if your market is <1M dies a year, you have to price your chip >$1 just to break even. And in the car chip market, even 1M dies is a giant amount. No, this is not the case. If you have a small run, the foundry will "consolidate" your chip with other customers to make a single mask. This makes sense all around, since the foundry would rather not have to deal with a mask set that has only a few wafer starts anyway.
      - baybal2 5y ago
        You don't make commercial chips on a shuttle run. If you sit on the same mask as somebody else, you forsake all the flexibility, and you are limited to fabs with own mask shops — just taking your masks, and moving to another fab with them is near impossible. Asking the fab to make just any process tweaks is similarly impossible.
        deleted 5y ago
        [deleted]
        nwiswell 5y ago
        I've never heard of a customer getting process tweaks for a one million die run, but then again I've got no experience with legacy fabs. Certainly the 14nm fab that Intel promised lately[1] for automotive demand would not entertain that sort of thing. [1] https://www.electronicdesign.com/markets/automotive/article/21174750/electronic-design-intel-to-commit-foundry-capacity-for-chipstarved-auto-industry https://www.electronicdesign.com/markets/automotive/article/...
- namibj 5y ago
  Especially considering that nowadays 180nm is accessible (if necessary, via double-patterning/immersion 405nm to please the DLP's aluminium mirrors) from maskless steppers, which can improve turn-around times by eliminating shared-mask aggregation delays and allows for cheap experimentation (no more minimum order quantity). This is even more significant when one remembers that maskless steppers already have to do stitching for everything significantly more complex than an opamp, and the per-area price scales up to full monolithic wafers without the tiling constrainst Cerebras has to adhere to.
fmajid 5y ago
> Effectively--nobody builds a line for an older node, ever. UMC, Taiwan's No. 2 fab, offered to build a new 64nm line in an existing fab in exchange for a $1B firm order commitment. Nobody bit, they preferred instead to lean on the Biden administration to pressure the Taiwanese government to allow them to skip the line. A new fab on old process nodes is not viable if it has to compete against fully amortized hand-me-down fabs that used to be cutting-edge 10-20 years ago.