Monday, July 13th 2026

JEDEC SPHBM4 Standard Enables HBM4-Class Bandwidth on Organic Substrates

JEDEC Solid State Technology Association, the global leader in standards development for the microelectronics industry, today announced the publication of JESD330-4: Standard Package High Bandwidth Memory (SPHBM4). SPHBM4 uses the same DRAM dies as HBM4, commonly used in artificial intelligence accelerators, with a new interface base die that enables mounting on standard organic substrates rather than silicon substrates. JESD330-4 is available for download from the JEDEC website.

JESD330-4 SPHBM is architected to operate at the same aggregate data throughput as HBM4 using fewer pins by operating at a higher frequency. Where the HBM4 interface has 2048 data signals, when published, SPHBM4 will define 512 data signals with 4:1 serialization to achieve the same bandwidth. This change allows the relaxed bump pitch required for connection to organic substrates.
Since SPHBM4 uses the same memory core layers as HBM4, total memory capacity per stack capability is identical. However, an added benefit of organic substrate routing is a longer supported channel length from the SoC to the memory, potentially increasing the total number of SPHBM stacks and therefore total memory capacity.

"JEDEC members are actively shaping the standards that will define next generation modules for use in AI data centers, driving the future of innovation in infrastructure and performance," said Mian Quddus, Chairman of the JEDEC Board of Directors.
Source: JEDEC
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3 Comments on JEDEC SPHBM4 Standard Enables HBM4-Class Bandwidth on Organic Substrates

#1
Aquinus
Resident Wat-man
I wonder what kind of side-effects of quadrupling the effective clock speed of the data lines is going to have. Higher frequency signals attenuate faster, so this is a really interesting statement:
Nomad76However, an added benefit of organic substrate routing is a longer supported channel length from the SoC to the memory
The substrate alone is allowing for this?
Posted on Reply
#2
shuffy_losys
AquinusThe substrate alone is allowing for this?
I haven't found anything pointing to organic substrates enabling longer traces, and most of the literature I've bothered to find seem to point that organic substrates are inferior in performance to silicon ones.

Google's no help either in trying to see if organic is better because they source this article and www.businesswire.com/news/home/20260713869107/en/New-JEDEC-SPHBM4-Standard-Enables-HBM4-Class-Bandwidth-on-Organic-Substrates
Posted on Reply
#3
Wirko
AquinusI wonder what kind of side-effects of quadrupling the effective clock speed of the data lines is going to have. Higher frequency signals attenuate faster, so this is a really interesting statement:

The substrate alone is allowing for this?
The explanation might be simply that organic substrates can be made in larger dimensions than silicon substrates.

There's also no mention of RDL (re-distribution layer). This might be necessary to make SPHBM work if they can't achieve high enough density with the substrate alone.
Posted on Reply
Nov 12th, 2026 04:40 CST change timezone

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