Component having a micromechanical microphone structure, and method for its production

US8637945B2 · kind B2 · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Frank Reichenbach · Wannweil, DE
• Thomas Buck · Tamm, DE
• Jochen Zoellin · Memmingen, DE
• Franz Laermer · Stuttgart, DE
• Ulrike Scholz · Ditzingen, DE
• Kathrin van Teeffelen · Stuttgart, DE
• Christina Leinenbach · Ensdorf, DE

Key dates

• Filing date: Apr 7, 2010
• Grant date: Jan 28, 2014
• Expiry date: Apr 7, 2030

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/31663
• WIPO field: Audio-visual technology
• WIPO sector: Electrical engineering

Abstract

A component having a robust, but acoustically sensitive microphone structure is provided and a simple and cost-effective method for its production. This microphone structure includes an acoustically active diaphragm, which functions as deflectable electrode of a microphone capacitor, a stationary, acoustically permeable counter element, which functions as counter electrode of the microphone capacitor, and an arrangement for detecting and analyzing the capacitance changes of the microphone capacitor. The diaphragm is realized in a diaphragm layer above the semiconductor substrate of the component and covers a sound opening in the substrate rear. The counter element is developed in a further layer above the diaphragm. This further layer generally extends across the entire component surface and compensates level differences, so that the entire component surface is largely planar according to this additional layer. This allows a foil to be applied on the layer configuration of the microphone structures exposed in the wafer composite, which makes it possible to dice up the components in a standard sawing process.