MEMS stress concentrating structure for MEMS sensors

• US 8,733,176 B2
• Filed: 09/01/2010
• Issued: 05/27/2014
• Est. Priority Date: 09/02/2009
• Status: Active Grant

• Current Assignee: Kontel Data System Limited
• Original Assignee: Kontel Data System Limited
• Inventors: Li, Ping Wai
• Primary Examiner(s): Caputo, Lisa
• Assistant Examiner(s): JENKINS, JERMAINE L
• Application Number:
  US12/873,684
• Publication Number:
  US 20110048138A1
• Time in Patent Office: 1,364 Days
• Field of Search: None
• US Class Current: 73/721
• CPC Class Codes: B81B 2201/0257 Microphones or microspeakers
• CPC Class Codes: B81B 2201/0264 Pressure sensors
• CPC Class Codes: B81B 3/0086 Electrical characteristics, e.g. reducing driving voltage, improving resistance to peak voltage
• CPC Class Codes: G01L 9/0042 Constructional details associated with semiconductive diaphragm sensors, e.g. etching, or constructional details of non-semiconductive diaphragms details about the integration or bonding of piezoresistor in or on the diaphragm G01L9/0052 and G01L9/0057 respectively
• CPC Class Codes: G01L 9/0054 integral with a semiconducting diaphragm
• CPC Class Codes: H04R 17/00 Piezoelectric transducers; Electrostrictive transducers piezoelectric or electrostrictive elements in general H10N30/00; details of piezoelectric or electrostrictive motors, generators or positioners H10N30/00
• CPC Class Codes: H04R 2201/003 Mems transducers or their use of the electrostatic type H04R19/005
• CPC Class Codes: H04R 23/006 using solid state devices solid state devices per se H01L
• CPC Class Codes: H04R 31/00 Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor manufacture of microstructural arrangements of deformable or non-deformable structures in general B81C1/00182
• CPC Class Codes: Y10T 29/42 Piezoelectric device making
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

A stress concentrating apparatus and a method for a MicroElectroMechanical System (MEMS) sensors is provided. The apparatus includes a plate having an inner region and outer region, the inner region being separated from the outer region by slits defined in the plate. A stress concentrator bridge connects the inner region to the outer region, and to mechanically amplify stress applied on the inner region of the plate. At least one stress sensor is operatively connected to the stress concentrator bridge, whereby the at least one stress sensor converts the mechanically amplified stress applied on the inner region into an electrical signal.

Claims

1. A method for manufacturing a stress concentration apparatus for MicroElectroMechanical System (MEMS) sensors, the stress concentration apparatus including a plate having an inner region and outer region, the inner region being separated from the outer region by slits defined in the plate;

a stress concentrator bridge configured to connect the inner region to the outer region and configured to mechanically amplify stress applied on the inner region of the plate; and

at least one stress sensor operatively connected to the stress concentrator bridge, wherein the at least one stress sensor converts the mechanically amplified stress applied on the inner region into an electrical signal, and wherein the inner region is thinner than the outer region,

the method comprising;

thinning down an inner region of the plate so that the inner region is thinner than an outer region thereof;

etching slits into the silicon plate to separate the inner region from the outer region;

connecting the inner region to the outer region with at least one stress concentrator bridge; and

refilling the slits with a substance or compound to separate upper and lower regions of the plate into two air-tight regions for sensing pressure,

wherein the stress concentration apparatus is for a pressure sensor.

2. A stress concentrating apparatus for MicroElectroMechanical System (MEMS) sensors, the apparatus comprising:

a plate having an inner region and outer region, the inner region being separated from the outer region by slits defined in the plate;

a stress concentrator bridge configured to connect the inner region to the outer region and configured to mechanically amplify stress applied on the inner region of the plate; and

at least one stress sensor operatively connected to the stress concentrator bridge,

wherein the at least one stress sensor converts the mechanically amplified stress applied on the inner region into an electrical signal,

wherein the inner region is thinner than the outer region,

wherein the stress concentration bridge has a constriction on at least one of a top surface or a bottom surface thereof.