I just finished dissecting an old Microsoft Wireless Optical Mouse. The mouse uses a CMOS image sensor with a 22 x 22 pixel sensor with a total resolution of 484 pixels. The CMOS Sensor IC (Integrated Circuit) is cased in a clear 32 pin tqfp package that allows you to see inside it. The mouse was a wireless model and had two RF coils on the circuit board.

I used Depth-of-Field stacking to enhance the clarity of the two images taken under a microscope. This involves taking about 15 pictures under the microscope at different levels of focus and then using a DOF stacking program to merge the focused part of each image into one ultra clear image. Helicon Focus or Adobe Photoshop are two good DOF Stacking programs. There is a GIF-A-Mation at the bottom of this post that shows the RF Coil image at different levels of focus.

Microsoft Optical Mouse CMOS Sensor

Wireless Mouse RF Coils

Depth of Field Stacking GIF Animation