Abstract: Described is a semiconductor substrate stack, including: a plurality of semiconductor substrates arranged in a stack in which the semiconductor substrates include opposing facing surfaces, wherein the facing surfaces of adjacent semiconductor substrates are separated by a gap, each semiconductor substrate having an edge surface at an exposed edge of the stack. A spacer is attached to one of the facing surfaces of each of the at least one of the semiconductor substrates and extends between adjacent semiconductor substrates to define the gap and mask a central portion of each respective semiconductor substrate.

Abstract: Described is a semiconductor substrate stack, comprising: a plurality of semiconductor substrates arranged in a stack in which the semiconductor substrates include opposing facing surfaces, wherein the facing surfaces of adjacent semiconductor substrates are separated by a gap, each semiconductor substrate having an edge surface at an exposed edge of the stack. A spacer is attached to one of the facing surfaces of each of the at least one of the semiconductor substrates and extends between adjacent semiconductor substrates to define the gap and mask a central portion of each respective semiconductor substrate.

Abstract: A high performance exhaust muffler which improves engine power and economy as well as providing a smoother engine performance. The muffler comprises an exhaust gas expansion section and a tubular baffle section closed or partially blocked at one end, its open end being attached within a smaller end of the exhaust gas expansion section to allow gas to pass directly into the exhaust gas expansion section and some to pass into the baffle section causing a weak back pressure to pulse back along the baffle tube.