LONDON – Reverse engineering and analysis consultancy Chipworks Inc. has torn down a few Samsung GT-E2550 GSM cell phones bought in the United States but intended for different geographic markets in Asia and Europe while on the hunt for phase-change memory ICs.
According to a technology blog by Rajest Krishnamurthy from Chipworks (Ottawa, Ontario) 512-Mbit phase-change memory (PCM) implanted in an approximately 65-nm manufacturing process was found in a multi-chip package in some of the phones.
The Samsung-produced PCM deployed in a Samsung GSM phone is the only known commercial deployment of a memory technology that had shown promise as a potential replacement for flash non-volatile memory technology. The continued scaling of flash memory and lack of uptake has cast doubt on the viability of PCM.
"The main PCB from a few of the GT-E2550 phones had a NOR flash multichip package (MCP) chip, with package marking K5N1229ACD. However, to our surprise, the PCB from some of the phones with specific branding name and with specific marks on the product label, used a PCM MCP memory chip with package marking K571229ACM, whereas others used a K5N122ACD NOR flash part," according to the Chipworks posting.
This confirms similar work by UBM Techinsights reported in December 2010 (see Phase-change memory found in handset
Numonyx, subsequently acquired by Micron Technologies Inc., released a 90-nm 128-Mbit phase-change memory in 2008, which it formalized as the Omneo range of serial and parallel access memories in April 2010. But the company has not said anything about design wins or volume production. Numonyx was also said to be developing a 1-Gbit phase-change memory in a 45-nm process, but there has been no news of sampling or volume production for a device that was expected to appear in 2010.
The posting includes package shots, x-ray photographs of the multi-chip packages and die shots of the equivalent phase-change memory (identified on the die as KPS1215EZA) and NOR flash (identified on the die as K8S1215EZC).
Chipworks states it is preparing structural analysis reports on both the 65-nm PCM and the 56-nm NOR flash integrated circuits.
Related links and articles:
Chipworks technology blog
China develops phase-change RAM
Academics scale PCM with carbon nanotubes
Samsung CEO: Headwinds hinder PRAM
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