Intel is announcing a new process change that will happen, it says, in the next decade. If you purchase a CPU these days, you are most likely purchasing a chip that is on an organic substrate. In the future, Intel is planning to use a glass substrate that better matches silicon properties.
Next-Gen Intel Packaging with Glass Substrates Transition Outlined
This is Intel’s last slide of the disclosure, but it is perhaps the best summary, so we are re-ordering here. Glass will allow higher interconnect density, the ability to integrate optical interconnects, and more making it better. Intel did not really discuss what would not be as good with glass other than it had to invent a lot of technology to make it work.
Here are Intel’s packaging options today and into the future. Your average Core processor is probably in the first camp and we have discussed EMIB a lot. Foveros is really interesting. We first covered Foveros in 2018. On the pre-briefing call, Intel gave color to the slide adding that the high-volume manufacturing ramp would happen later in 2023. That gives some sense of where Intel is on delivering these to the mass market. Foveros Direct with direct copper-to-copper bonding is being touted as something coming “very soon.”
The Glass Core Substrate will do things like improve power delivery and get high-efficiency I/O on the package. Intel also is planning a glass-based coupling with integrated waveguides for the pluggable co-packaged optics that were shown at Intel Innovation 2022.
Intel showed a history of processor substrates. Organic and Organic with EMIB are going to continue for some time, but the high-end AI and data center CPUs seem to be the initial target for glass core.
The organic substrate one can think of as being very similar to standard PCB material. Glass in that context is more like fiberglass layers with a resin. We are simplifying this a lot to make it a bit more accessible.
Glass cores, by contrast, are a homogeneous material, unlike the fiberglass and resin materials used in organic substrates. It can be tuned to have thermal expansion similar to silicon which helps make larger form factor pacakages. Intel thinks it can get 10x or more through-hole density versus organic substrates. Intel also thinks it can get to lower loss and higher speed signaling like 448G.
Perhaps the fun one for folks on this slide is the TGV, or Through Glass Via. Many are familiar with Through Silicon Via or TSV, now that is being adapted to glass.
This is one of those really cool Intel disclosures, and that is probably why Intel has it going live before Innovation 2023. Intel has these research products where there are teams working on technology like this for years, and it will not make it to production for years to come. Here is the progress thus far over the last decade, with a dedicated pathfinding effort that has been running for the last three years.
The middle and right images above are from the actual chips that have been tested using this new technology.
Overall, this is one of those really cool technology disclosures that is not going to make it into 2024 chips, but hopefully, we get to see it on a longer time horizon.