The A16 has a very strange packaging (vaguely described in this article). https://eetimes.itmedia.co.jp/ee/articles/2210/25/... It *seems* to be something like the above, with a glass slab, DRAM on one side, and TGVs connecting to the SoC on the other side. It's certainly very different from the standard PoP as used by iPhones (and other phones) since forever.
Everything about this packaging is mysterious, but one wonders if it was something of a trial run for future M-series designs that put the DRAM "behind" rather than "beside" the SoC. For that to work you need a large enough substrate to reach to Ultra (or the mythical Extreme) sizes, but if DNP can do this at ~5cm x 5cm maybe that's large enough. For your extra cost presumably you get improved electrical stiffness (ie lower capacitance, and so higher frequency signals and/or lower energy wasted in the DRAM<->SoC traffic).
The other thing you have to bear in mind with these sorts of designs is thermal expansion. You don't want the substrate to expand at a slightly different rate from the SoC and thus put mechanical strain on the connecting wires... And this becomes more and more of an issue as you grow larger. Presumably the glass has been matched to silicon's coefficient of thermal expansion, and this may be a lot easier to achieve (and thus worth it just for that functionality) than trying to match a resin substrate to Si thermal expansion? The other alternative of course is to use Si itself as the substrate, but that's another leap in expense, so if glass can replace many of those Si interposer use cases...
The article calls the A16 slab "glass epoxy" as opposed to just "glass" but who knows what that means?
In chemistry, the most frequently used definition of the term "organic substance" is a chemical substance composed of molecules that include covalent carbon-carbon bonds.
The reason is that this kind of chemical substances have been initially discovered by the study of substances extracted from the bodies of living beings, even if nowadays such substances are produced also or only by artificial chemical synthesis.
When the materials used in fabrication processes are described, the standard chemical terminology is used, unlike when advertising food or dietary supplements.
Fun fact, I went to Evergreen Park High School. In fact I still live 5 blocks away. Ted Kaczynski is still popular around here, more so than Jenny McCarthy.
Because epoxy is an organic compound. The word organic in this case means "carbon-based." Organic chemistry is a whole subfield of chemistry that deals with organic compounds.
I know that one of the reasons the current organic substrates are still seen as viable for the future is that optical fibers can be embedded into current manufacturing. Part of these technologies were for off package communication while others were to improve die-to-die connectivity when silicon photonics became viable for mainstream adoption. One barrier to entry is the various patents here embedding optical fibers is spread throughout the industry. I assumed that some of these were handled in the cross licensing agreement between Intel and IBM a few years ago. My hope was that we'd be seeing such products in the future.
With regards to glass substrates though, I would presume that this has a very similar thermal expansion rate to a silicon wafer itself. Normalizing expansion rates makes dealing with the mechanical stress of thermal cycles far, far easier. The embedded wiring might have the secondary effect of acting as a means to help transfer heat uniformly throughout the structure. My concern is that hot spots could lead to shattering the substrate if the internal stresses from thermal expansion are not handled well.
Well, let's say I'm not going to try dropping a CPU onto a concrete floor.
If you drop a device *containing* a CPU, the device's case will probably absorb enough shock that I'd guess you won't have sufficient shear forces, at the substrate, to kill it. Also, having a thermal solution clamped onto it should help couple the entire package to the board, which should also help.
We’ve updated our terms. By continuing to use the site and/or by logging into your account, you agree to the Site’s updated Terms of Use and Privacy Policy.
Facebook
Twitter
RSS
17 Comments
Back to Article
name99 - Thursday, March 23, 2023 - link
The A16 has a very strange packaging (vaguely described in this article).https://eetimes.itmedia.co.jp/ee/articles/2210/25/...
It *seems* to be something like the above, with a glass slab, DRAM on one side, and TGVs connecting to the SoC on the other side.
It's certainly very different from the standard PoP as used by iPhones (and other phones) since forever.
Everything about this packaging is mysterious, but one wonders if it was something of a trial run for future M-series designs that put the DRAM "behind" rather than "beside" the SoC. For that to work you need a large enough substrate to reach to Ultra (or the mythical Extreme) sizes, but if DNP can do this at ~5cm x 5cm maybe that's large enough.
For your extra cost presumably you get improved electrical stiffness (ie lower capacitance, and so higher frequency signals and/or lower energy wasted in the DRAM<->SoC traffic).
The other thing you have to bear in mind with these sorts of designs is thermal expansion. You don't want the substrate to expand at a slightly different rate from the SoC and thus put mechanical strain on the connecting wires... And this becomes more and more of an issue as you grow larger.
Presumably the glass has been matched to silicon's coefficient of thermal expansion, and this may be a lot easier to achieve (and thus worth it just for that functionality) than trying to match a resin substrate to Si thermal expansion? The other alternative of course is to use Si itself as the substrate, but that's another leap in expense, so if glass can replace many of those Si interposer use cases...
The article calls the A16 slab "glass epoxy" as opposed to just "glass" but who knows what that means?
Wereweeb - Thursday, March 23, 2023 - link
"Glass epoxy" is fibreglass, i.e. organic substrate. Nothing strange about it.Samus - Friday, March 24, 2023 - link
How is glass epoxy 'organic' when epoxy is a thermoplastic polymer, a synthetic material?AdrianBc - Friday, March 24, 2023 - link
In chemistry, the most frequently used definition of the term "organic substance" is a chemical substance composed of molecules that include covalent carbon-carbon bonds.The reason is that this kind of chemical substances have been initially discovered by the study of substances extracted from the bodies of living beings, even if nowadays such substances are produced also or only by artificial chemical synthesis.
When the materials used in fabrication processes are described, the standard chemical terminology is used, unlike when advertising food or dietary supplements.
Wereweeb - Friday, March 24, 2023 - link
Ah, yes, now I understand, the fault lays with the "organic food" yank nonsense.Personally I much prefer the inorganic kind of food, like clay cookies and limestone pastries.
LiKenun - Saturday, March 25, 2023 - link
An excellent source of minerals like calcium!mode_13h - Sunday, March 26, 2023 - link
At least they have a longer shelf-life!Wereweeb - Friday, March 24, 2023 - link
Organic = hydrocarbon-based. Petroleum and almost all of it's derivates are organic by definition.I can't fathom how you could possibly be confused about that, since we're talking about primary school level chemistry.
III-V - Friday, March 24, 2023 - link
Most primary schools don't cover chemistry at all, lolThreska - Saturday, March 25, 2023 - link
Is that were we all learned to be the unabomber?Samus - Monday, March 27, 2023 - link
Fun fact, I went to Evergreen Park High School. In fact I still live 5 blocks away. Ted Kaczynski is still popular around here, more so than Jenny McCarthy.BvOvO - Friday, March 24, 2023 - link
You are mixing biologic and organic. Organic essentialy is carbon chemistry. So synthetic fibers that have carbon-carbon bonds are organic.Astrogardener - Friday, March 24, 2023 - link
Because epoxy is an organic compound. The word organic in this case means "carbon-based." Organic chemistry is a whole subfield of chemistry that deals with organic compounds.Threska - Friday, March 24, 2023 - link
V'Ger: Carbon-based unit.Kevin G - Thursday, March 23, 2023 - link
I know that one of the reasons the current organic substrates are still seen as viable for the future is that optical fibers can be embedded into current manufacturing. Part of these technologies were for off package communication while others were to improve die-to-die connectivity when silicon photonics became viable for mainstream adoption. One barrier to entry is the various patents here embedding optical fibers is spread throughout the industry. I assumed that some of these were handled in the cross licensing agreement between Intel and IBM a few years ago. My hope was that we'd be seeing such products in the future.With regards to glass substrates though, I would presume that this has a very similar thermal expansion rate to a silicon wafer itself. Normalizing expansion rates makes dealing with the mechanical stress of thermal cycles far, far easier. The embedded wiring might have the secondary effect of acting as a means to help transfer heat uniformly throughout the structure. My concern is that hot spots could lead to shattering the substrate if the internal stresses from thermal expansion are not handled well.
GC2:CS - Friday, March 24, 2023 - link
Hmm. So if by accident i manage to drop a new CPU (or a device containing it) by accident, will it break like a smartphone ?mode_13h - Sunday, March 26, 2023 - link
Well, let's say I'm not going to try dropping a CPU onto a concrete floor.If you drop a device *containing* a CPU, the device's case will probably absorb enough shock that I'd guess you won't have sufficient shear forces, at the substrate, to kill it. Also, having a thermal solution clamped onto it should help couple the entire package to the board, which should also help.