Identifying HDD IC markings - ST313021A case study

Research and Development. This is the place to report experimental stuff related to data recovery.
fzabkar
Contributor
Contributor
Posts: 550
Joined: Tue Apr 16, 2013 9:28 am
Location: Australia

Identifying HDD IC markings - ST313021A case study

Postby fzabkar » Sat Apr 27, 2013 1:17 am

Identifying HDD IC markings - ST313021A case study

This case study is intended to assist the reader in identifying HDD IC part markings. Our example will be a Seagate ST313021A HDD.

Seagate Barracuda 7200.10 ST3320620A hires PCB photos:
viewtopic.php?f=112&t=110

The attachments show the MCU, motor controller, and read channel ICs:

ST313021A_MCU.JPG
ST313021A_MCU.JPG (34.02 KiB) Viewed 1823 times
ST313021A_motor_control.jpg
ST313021A_motor_control.jpg (24.57 KiB) Viewed 1823 times
ST313021A_read_channel.JPG


The IC manufacturers are identified by their logos - STMicroelectronics and Infineon Technologies. Infineon was created when Siemens spun off its semiconductor division into a new company, hence the Siemens copyright notice.

The next most obvious markings are the countries of manufacture (Taiwan, France, Malaysia). Often one will find that US HDD manufacturers will source their ICs from US or European chip makers whereas the Japanese usually source from other Japanese companies, often their own.

ICs will generally have date codes and/or batch codes. Most often these will be in YWW or YYWW (Year / Week) format. The photos show that the ICs were manufactured during weeks 05 and 07 of 2000.

The Infineon MCU has a Siemens/Infineon part number of MAB-M3005-8D. The "MAB" prefix is and was used by Siemens/Infineon and Philips/NXP for their range of microcontrollers.

For example, a search for "MAB* microcontroller Siemens" at http://www.datasheetarchive.com will produce numerous hits such as "MAB8049" which is an old 8-bit microcontroller.

All three ICs appear to have Seagate internal part numbers:

    23400278-002
    SG70021-501
    SG70014-502
These numbers suggest that these ICs may have been especially produced for Seagate. The similar "SG" numbers on parts from different IC manufacturers would tend to confirm that these are not STMicroelectronics or Infineon part codes.

"ATLANTIS" appears to be the code name for the MCU, probably Seagate's.

The other markings could be batch codes or serial numbers.

The following examples (from Google Images) show that the "EC" marking code is ordered alphanumerically by date:

Code: Select all

marking   YYWW

EC006089  9947
EC020127  0007
EC032111  0019

This would suggest that the marking may be a serial number.

The markings on the motor controller also appear to be ordered by date in some way. However the variation seems to be too small for a serial number. Instead I suspect that the first 5 characters may reflect a batch code. I believe the same would apply for the read channel IC.

    1A81S 9929
    1A82U 9949
    1A8CN 0007
    NA8HZ 0019

fzabkar
Contributor
Contributor
Posts: 550
Joined: Tue Apr 16, 2013 9:28 am
Location: Australia

Re: Identifying HDD IC markings - ST313021A case study

Postby fzabkar » Sat Apr 27, 2013 1:40 am

Oops, too late to edit.

The part number of the Infineon MCU is SAB-M3005-8D, not MAB-M3005-8D.

That said the "SAB" prefix is also commonly used for microcontrollers.


Return to “R&D - Experiments”

Who is online

Users browsing this forum: No registered users and 1 guest