The capacitive touch sense buttons in the Mighty Mouse's top shell are what enable the Mighty mouse to have the coveted right and left mouse buttons. The choice of capacitive touch sense enable the mouse to perfectly emulate a single button mouse because the user is not exposed to any seams in the case or multiple sources of "click" noises. The mighty mouse only has one "click" button in it, but, more on that later.

The capacitive touch sense buttons are formed by a serpentine pattern in the green flex circuit that is firmly attached to the under side of the Might Mouse's top shell. The "right" and "left" buttons each consist of two interlocking serpentine patterns. These patterns form the plates of the capacitive interface that sense the presence of your finger. One might think that this would be the full extent of the capacitive interface. However, as mentioned earlier the green flex cable has 5 conductors. The fifth conductor terminates to a copper plate located near the length wise middle of the mouse. I'm not sure what this copper place is for, my assumption is that it provides some type of reference input to the capacitive circuits.

The Mighty Mouse main PCB is a simple two sided copper board with a combination of through hole and surface mount components. The top side of the board has all though hole components whereas the bottom is surface mount only. This arrangement simplifies assembly of the board.

On the top of the PCB are three headers, three passive components, a switch, piezo electric buzzer, optical tracking chip, and a large plastic assembly that forums the top shell suspension and finger hold force sensing buttons.

The force sensing buttons are the most interesting part of the of the PCB. Calling these force sensing buttons may be a bit misleading. The buttons are formed out of thick metal separated by a non-conductive material. When one presses on the finger hold buttons on the side of the mouse that force is transfered to the outside metal plate. If enough force is used the pate is deflected enough to over come the separation provided by the non-conductive material and the button's circuit is closed. Could de-bouncing this puppies be the reason for the dual flip-flop chip on the other side of the board? Perhaps not, but, I'm not tracing out the PCB to find out.

One the bottom of the PCB are numerous surface mount components and a hole that allows the optical tracking chip to see through the board. Compared to the size of the surface mount capacitors and resistors there three large SSOP chips on the board. One of them is an ON Semiconductor HC74A (dual flip-flop) and a 14-pin chip I have not been able to identify labeled, FPSC02S 5098150-09.