This part was taken from a Motronic M1.7.3 engine control unit (ECU), which was commonly used on 1.6L & 1.8L 4-cylinder BMWs of the mid-E36 generation. While this chip was likely used on a number of ECUs, the specific one in this case had Bosch PN 0 261 203 661.

This chip is believed to be a Hitachi HM6264B 8KB SRAM. It provides XRAM to the 80C515 MCU used in the ECU.

Datasheet: http://esd.cs.ucr.edu/webres/hm6264b.pdf

Label (top):

B57826 (Bosch internal PN)
JAPAN 9607HCK

Decap Steps:
(Bic lighter + water quench) x 2 cycles
Selective crushing with pliers and bench vise

Capture Details:
Imaging device: Keyence VHX-2000
Magnification: 250X

Markings:
66460 (possibly, the die needs to be reimaged due to stitching errors)

The die seemed to have a polyimide (“Kapton”) coating over most of its surface. Attempts to peel it off were unsuccessful, so it was imaged with this intact.

Note: This is a ~4X downsampled version of the original image. A full resolution version (17MB) can be provided. On the to-do list…