8 ms·

I know they're separate lines and capacity is sold well in advance and all that, but this chip shortage still baffles me. A startup can tape out a 5 nm chip, b

by ohazi 6y ago

I know they're separate lines and capacity is sold well in advance and all that, but this chip shortage still baffles me. A startup can tape out a 5 nm chip, but STMicroelectronics can't make any of their 40-130 nm microcontrollers for the next year? Also car companies are supposedly the culprit, even though their volume is only in the low tens of millions per year, and the dustup is apparently over only six months of capacity? What? I get that the auto industry is a nice reliable long-term source of revenue for chip companies, but fabs should barely be sneezing at that sort of volume.

bravo22 6y ago
A lot of chips are made on mature fab lines because they don't need the performance of 5nm lines or can't justify the mask costs. No one is investing in mature fab lines because they're not leading edge and they're being run to amortize the initial investmnet made into them years ago. Therefore not much additional capacity for mature lines. So yes you can see 5nm chips being taped out but the 40-130nm chips are squeezed for capacity. Also this chip is likely not running in the same crazy volumes that ST microcontrollers. It is easier for TSMC to squeeze in a few dozen to a hundred wafers for SiFive on their line.
- variaga 6y ago
  Your point is valid, but this is almost certainly a shuttle run, so it won't be even one full wafer.
  - bravo22 6y ago
    You're right. Definitely a "hot" wafer for the engineering samples.
- dragontamer 6y ago
  > A lot of chips are made on mature fab lines because they don't need the performance of 5nm lines or can't justify the mask costs. Alternatively: they're car-scale products dealing primarily with high electric currents (10s or 100s of milliamps) and/or higher voltages (5V instead of 1.3V). Smaller chips use (and therefore output) less current than larger scale chips. But if your goal is to output 10mA to better drive an IGBT or other transistor anyway, then you really prefer 40nm to 130nm ANYWAY, because those larger sizes are just a lot better at moving those large currents around. Bigger wires mean bigger currents.
  - bravo22 6y ago
    High voltage MOSFETs and IGBTs are built on a completely different process. Size is definitely not an issue with them. It is about exotic doping to create the desired characteristics. They're built using much larger feature sizes but on completely separate lines.
    - dragontamer 6y ago
      I'm not really in the industry. But I know that high-voltage MOSFETs / IGBTs need substantial amounts of current to turn on / off adequately. Under typical use, there's a dedicated chip called a "Gate Driver" that provides that current, between a microcontroller and the IGBT. Its not that the IGBT / MOSFETs are built on these microcontrollers. Its that the Gate-Driver can be integrated into a microcontroller (simplifying the circuit design and reducing the number of parts you need to buy). Under normal circumstances, a microcontroller can probably source/sink 1mA (too little to adequately turn on an IGBT). You amplify the 1mA with a gate-driver chip into 100mA, and then the amplified 100mA is used to turn on/off the IGBT. By integrating a gate-driver into the microcontroller, you save a part.
      - bravo22 6y ago
        Gate drivers are discrete parts and aren't integrated into microcontorllers because they require high voltages (12/24V vs 3.3V) amongst many other reasons. They also have to be located close to the IGBT and the designers would want it as a separate part because it gives them enormous flexibility. You aren't saving much by adding a gate driver to a micro and I can't think of any micro that has it integrated. There are simple things like motor drivers, etc. that may have a gate driver integrated but that's not a micro and those are also built on large nodes -- much larger than nodes used for microcontrollers. FWIW: I design advanced node (20-5nm) ASICs for a living, and have designed on older nodes before. I've also worked in power electronics.
Kliment 6y ago
This is an extremely low volume prototype run. You can get those scheduled on short notice. Fabs love them because they can do process optimization using them, without impacting production customers. They're ridiculously expensive per-die and you commit to accept a much higher failure rate than normal. ST can and is making microcontrollers. It's just that they've sold their production for a year ahead, before it's even been manufactured. Car companies fucked everyone over by flipping a large volume of orders back and forth causing bullwhip effect on the whole industry, and lots of knock-on effects in other industries who suddenly got told (occasionally too late) that they need to plan their inventory a year ahead because they can't get anything at short notice anymore. Car companies vehicle production volume is tens of millions, but each vehicle has thousands to tens of thousands of ICs. The six months you are mentioning are not the capacity period, they are the lead times involved. I don't want to repeat the whole story but I wrote a comment about this on another thread. See https://news.ycombinator.com/item?id=26659709 https://news.ycombinator.com/item?id=26659709
- ohazi 6y ago
  > Fabs love them because they can do process optimization using them, without impacting production customers. I didn't realize that, but it makes a lot of sense. I assumed that they acted more like the downstream manufacturers that I'm used to dealing with, that don't even want to talk to you unless they think you're going to place a huge order.
- jankeymeulen 6y ago
  Thousands to tens of thousands per car? I think you're off by an order of magnitude.
  - mschuster91 6y ago
    Almost everything in a car has a number of chips. Power regulations, communication buses... and in electric cars with thousands of batteries, at least one chip per battery for protection.
    - 6y ago
lizknope 6y ago
I'm in the semiconductor company. I don't really understand your question. Anyone can start a company and tape out a chip even in 5nm. My previous startup did something similar. We used an intermediate company between us and TSMC that specifically works with smaller companies. They (or TSMC) will bundle together 4 to 20 chips into a common mask as a "shuttle" run. Shuttle runs are really only used to get samples for the first version of your chip. You can't really go to production with them because the mask has chips from multiple different companies but this allows all of the companies to share the mask costs (I've heard up to $30 million for 5nm) What is ST Micro talking about? I assume they can produce chips but can't get the volume that they want. SiFive are probably producing about 2,000 of these chips for development and test boards. ST Micro would be buying in the hundreds of millions or tens of billions range.
- zibzab 6y ago
  Sounds like OSH Park for silicon... Anyway, I'm still not sure why SiFive is doing this. Seems like a waste of money even as a prototype
  - variaga 6y ago
    SiFive is in the business of selling IP cores and back-end implementation services. The gold standard for IP core validation is "silicon proven" i.e. that it's not just a nice theoretical design on paper, but someone has actually turned it into a physical chip and tested the real life performance. Lots of people will try to sell you their designs and services. Picking the wrong ones can waste millions of dollars and months/years of time. The money spent on this a prototype buys SiFive credibility for both aspects of their business (assuming the chip works) - "we were able to do this for ourselves, so you know we'll be able to do it for you". So it's not a waste, it's a marketing expense, and a necessary one.
  - lizknope 6y ago
    The article mentions that is is from the OpenFive division of SiFive. OpenFive used to be Open Silicon and their business model was working with other companies to take their Verilog RTL and do all of the physical design (synthesis to logic gates, place and route of the standard cells, timing analysis, test vector generation) and then work with the foundries to deliver all of the data for manufacturing. Since Open Silicon is now OpenFive and part of SiFive they literally have all this experience in house and don't need to depend on another company between them and TSMC. https://en.wikipedia.org/wiki/Open-Silicon https://en.wikipedia.org/wiki/Open-Silicon
PragmaticPulp 6y ago
> Also car companies are supposedly the culprit, even though their volume is only in the low tens of millions per year, and the dustup is apparently over only six months of capacity? What? I get that the auto industry is a nice reliable long-term source of revenue for chip companies, but fabs should barely be sneezing at that sort of volume. I agree. I think the blame on automakers has been blown out of proportion. It doesn't make any sense that automakers cancelled orders, then reinstated those orders again with some extra demand, and now the entire chip market is stalled. It's most likely due to the fact that consumer demand is up everywhere. The pandemic didn't hit the economy nearly as hard as expected, and we piled a lot of stimulus on top of that. Savings rate went up a bit, but much discretionary spending was diverted away from things like dining out and toward buying consumer goods. > STMicroelectronics can't make any of their 40-130 nm microcontrollers for the next year They're almost certainly making huge volumes of microcontrollers, but they're all spoken for with orders from the highest bidders. We won't have inventory sitting on shelves again until fab capacity isn't being 100% occupied by existing orders. Need some surplus before we can get parts at DigiKey.
monocasa 6y ago
ST fabs their own chips. If their fabs don't have the capacity, it's a huge slog to tape them out to a radically different process at another company.

by ohazi 6y ago

bravo22 6y ago

A lot of chips are made on mature fab lines because they don't need the performance of 5nm lines or can't justify the mask costs. No one is investing in mature fab lines because they're not leading edge and they're being run to amortize the initial investmnet made into them years ago. Therefore not much additional capacity for mature lines. So yes you can see 5nm chips being taped out but the 40-130nm chips are squeezed for capacity. Also this chip is likely not running in the same crazy volumes that ST microcontrollers. It is easier for TSMC to squeeze in a few dozen to a hundred wafers for SiFive on their line.

variaga 6y ago
Your point is valid, but this is almost certainly a shuttle run, so it won't be even one full wafer.
- bravo22 6y ago
  You're right. Definitely a "hot" wafer for the engineering samples.
dragontamer 6y ago
> A lot of chips are made on mature fab lines because they don't need the performance of 5nm lines or can't justify the mask costs. Alternatively: they're car-scale products dealing primarily with high electric currents (10s or 100s of milliamps) and/or higher voltages (5V instead of 1.3V). Smaller chips use (and therefore output) less current than larger scale chips. But if your goal is to output 10mA to better drive an IGBT or other transistor anyway, then you really prefer 40nm to 130nm ANYWAY, because those larger sizes are just a lot better at moving those large currents around. Bigger wires mean bigger currents.
- bravo22 6y ago
  High voltage MOSFETs and IGBTs are built on a completely different process. Size is definitely not an issue with them. It is about exotic doping to create the desired characteristics. They're built using much larger feature sizes but on completely separate lines.
  - dragontamer 6y ago
    I'm not really in the industry. But I know that high-voltage MOSFETs / IGBTs need substantial amounts of current to turn on / off adequately. Under typical use, there's a dedicated chip called a "Gate Driver" that provides that current, between a microcontroller and the IGBT. Its not that the IGBT / MOSFETs are built on these microcontrollers. Its that the Gate-Driver can be integrated into a microcontroller (simplifying the circuit design and reducing the number of parts you need to buy). Under normal circumstances, a microcontroller can probably source/sink 1mA (too little to adequately turn on an IGBT). You amplify the 1mA with a gate-driver chip into 100mA, and then the amplified 100mA is used to turn on/off the IGBT. By integrating a gate-driver into the microcontroller, you save a part.
    - bravo22 6y ago
      Gate drivers are discrete parts and aren't integrated into microcontorllers because they require high voltages (12/24V vs 3.3V) amongst many other reasons. They also have to be located close to the IGBT and the designers would want it as a separate part because it gives them enormous flexibility. You aren't saving much by adding a gate driver to a micro and I can't think of any micro that has it integrated. There are simple things like motor drivers, etc. that may have a gate driver integrated but that's not a micro and those are also built on large nodes -- much larger than nodes used for microcontrollers. FWIW: I design advanced node (20-5nm) ASICs for a living, and have designed on older nodes before. I've also worked in power electronics.

Kliment 6y ago

This is an extremely low volume prototype run. You can get those scheduled on short notice. Fabs love them because they can do process optimization using them, without impacting production customers. They're ridiculously expensive per-die and you commit to accept a much higher failure rate than normal. ST can and is making microcontrollers. It's just that they've sold their production for a year ahead, before it's even been manufactured. Car companies fucked everyone over by flipping a large volume of orders back and forth causing bullwhip effect on the whole industry, and lots of knock-on effects in other industries who suddenly got told (occasionally too late) that they need to plan their inventory a year ahead because they can't get anything at short notice anymore. Car companies vehicle production volume is tens of millions, but each vehicle has thousands to tens of thousands of ICs. The six months you are mentioning are not the capacity period, they are the lead times involved. I don't want to repeat the whole story but I wrote a comment about this on another thread. See https://news.ycombinator.com/item?id=26659709 https://news.ycombinator.com/item?id=26659709

ohazi 6y ago
> Fabs love them because they can do process optimization using them, without impacting production customers. I didn't realize that, but it makes a lot of sense. I assumed that they acted more like the downstream manufacturers that I'm used to dealing with, that don't even want to talk to you unless they think you're going to place a huge order.
jankeymeulen 6y ago
Thousands to tens of thousands per car? I think you're off by an order of magnitude.
- mschuster91 6y ago
  Almost everything in a car has a number of chips. Power regulations, communication buses... and in electric cars with thousands of batteries, at least one chip per battery for protection.
  - 6y ago

lizknope 6y ago

I'm in the semiconductor company. I don't really understand your question. Anyone can start a company and tape out a chip even in 5nm. My previous startup did something similar. We used an intermediate company between us and TSMC that specifically works with smaller companies. They (or TSMC) will bundle together 4 to 20 chips into a common mask as a "shuttle" run. Shuttle runs are really only used to get samples for the first version of your chip. You can't really go to production with them because the mask has chips from multiple different companies but this allows all of the companies to share the mask costs (I've heard up to $30 million for 5nm) What is ST Micro talking about? I assume they can produce chips but can't get the volume that they want. SiFive are probably producing about 2,000 of these chips for development and test boards. ST Micro would be buying in the hundreds of millions or tens of billions range.

zibzab 6y ago
Sounds like OSH Park for silicon... Anyway, I'm still not sure why SiFive is doing this. Seems like a waste of money even as a prototype
- variaga 6y ago
  SiFive is in the business of selling IP cores and back-end implementation services. The gold standard for IP core validation is "silicon proven" i.e. that it's not just a nice theoretical design on paper, but someone has actually turned it into a physical chip and tested the real life performance. Lots of people will try to sell you their designs and services. Picking the wrong ones can waste millions of dollars and months/years of time. The money spent on this a prototype buys SiFive credibility for both aspects of their business (assuming the chip works) - "we were able to do this for ourselves, so you know we'll be able to do it for you". So it's not a waste, it's a marketing expense, and a necessary one.
- lizknope 6y ago
  The article mentions that is is from the OpenFive division of SiFive. OpenFive used to be Open Silicon and their business model was working with other companies to take their Verilog RTL and do all of the physical design (synthesis to logic gates, place and route of the standard cells, timing analysis, test vector generation) and then work with the foundries to deliver all of the data for manufacturing. Since Open Silicon is now OpenFive and part of SiFive they literally have all this experience in house and don't need to depend on another company between them and TSMC. https://en.wikipedia.org/wiki/Open-Silicon https://en.wikipedia.org/wiki/Open-Silicon

PragmaticPulp 6y ago

> Also car companies are supposedly the culprit, even though their volume is only in the low tens of millions per year, and the dustup is apparently over only six months of capacity? What? I get that the auto industry is a nice reliable long-term source of revenue for chip companies, but fabs should barely be sneezing at that sort of volume. I agree. I think the blame on automakers has been blown out of proportion. It doesn't make any sense that automakers cancelled orders, then reinstated those orders again with some extra demand, and now the entire chip market is stalled. It's most likely due to the fact that consumer demand is up everywhere. The pandemic didn't hit the economy nearly as hard as expected, and we piled a lot of stimulus on top of that. Savings rate went up a bit, but much discretionary spending was diverted away from things like dining out and toward buying consumer goods. > STMicroelectronics can't make any of their 40-130 nm microcontrollers for the next year They're almost certainly making huge volumes of microcontrollers, but they're all spoken for with orders from the highest bidders. We won't have inventory sitting on shelves again until fab capacity isn't being 100% occupied by existing orders. Need some surplus before we can get parts at DigiKey.

monocasa 6y ago

ST fabs their own chips. If their fabs don't have the capacity, it's a huge slog to tape them out to a radically different process at another company.