Recently I was called by a former co-worker who had moved
to another company. He asked if I could design and build a really
tiny charge amplifier, one which would fit into an eighth of a cubic inch.
The resulting printed wiring board is shown below, shown larger than real
life.
The customer needed an amplifier which would fit into
a cavity which was 0.25 x 0.25 x 2.0 inches, so the printed wiring board
was designed to be not very long, and very skinny. The upper board
is the amplifier back side, the middle board is the amplifier front side
minus the 2000 megohm and 10000 megohm resistors. The bottom board
is shown with the resistors attached. Voila! A tiny amplifier
to fit their requirement.