MEMS microphone with spring suspended backplate

A MEMS microphone comprising:

• a base;
• a backplate having a plurality of apertures;
• a backplate spring suspending the backplate from the base, the backplate spring being a single solid member and substantially serpentine-shaped;
• and
• a diaphragm forming a variable capacitor with the backplate, wherein the diaphragm has a diaphragm spring with a diaphragm spring constant, the backplate spring having a backplate spring constant, the backplate spring constant being at least ten times larger than the diaphragm spring constant.

A method of reducing stress on a MEMS microphone backplate, the method comprising:

• providing a base;
• supporting a diaphragm on the base;
• forming a variable capacitor by spacing a backplate from the diaphragm, the backplate being connected to the base with a plurality of springs configured to reduce stress on the backplate, the spring being a single solid member and substantially serpentine-shaped;
• and
• applying an incident audio signal of a spoken human voice against the backplate and diaphragm while the base remains substantially immovable, the backplate remaining substantially immovable upon receipt of the audio signal.

A MEMS microphone comprising:

• a base;
• a backplate having a plurality of trenches and a central portion with through-holes, the backplate trenches substantially circumscribing the through-holes, the backplate comprised of a static backplate, the trenches creating an active sensing area of the backplate, the active sensing area located radially inward from the trenches and being effectively isolated;
• and
• wherein when the microphone is stationary, the backplate spring has a spring constant that is high enough to cause the backplate to remain substantially stationary upon receipt of audio signals having amplitudes on the order of magnitude of the human speaking voice.