Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Election/Restrictions
Applicant’s election without traverse of Group I ( Claims 1-9) in the reply filed on December 31, 2025 is acknowledged.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1-3 are rejected under 35 U.S.C. 103 as being unpatentable over Chandrasekaran et al. (US20210204048A1) in view of Suzuki (US20070121972A1).
As to Claim 1, Chandrasekaran teaches a MEMS microphone ( acoustic transducers using MEMS technology, [0003] and abstract), comprising: a substrate ( substrate 212, Figure 2, [0033]) including an air chamber in a central portion ( first opening 213, [0033]); a back-plate (240, Figure 2) disposed above the substrate( 212) and including a plurality of penetration holes through which a sound wave passes( the back plate 240 is disposed in the cavity 242 between the first and second diaphragms 220 and 230. In some embodiments, one or more apertures 252 may be defined in the back plate 240, [0037]); and a vibration membrane ( first diaphragm 220) disposed between the back-plate ( 240) and the substrate( 212), having a base form convexly bent toward the back-plate ( as shown on Figure 2, the first diaphragm 220 is convexly bent towards the backplate 240), and configured to vibrate a sound pressure transferred through the plurality of penetration holes ( the transducer 200 generates electric signals responsive to acoustic signals or atmospheric pressure changes, [0032]). Chandrasekaran does not explicitly teach “ forming a compressive stress”. However, Suzuki in related field ((capacitive MEMS transducer) teaches a capacitor microphone, a diaphragm is positioned opposite to a fixed electrode for covering inner holes of a ring-shaped support, wherein when the diaphragm is deflected to approach the fixed electrode due to electrostatic attraction upon application of a bias voltage, internal stress that occurs on the diaphragm is canceled by compressive stress that is applied to the diaphragm in advance. [0022] teaches the diaphragm be formed by laminating a tensile stress film having tensile stress and a compressive stress film having compressive stress. It would have been obvious to one of ordinary skill in the art, before the effective filing date of the invention to modify the diaphragm with a compressive stress so that when the diaphragm is deflected to approach the fixed electrode due to the electrostatic attraction caused by applying a bias voltage between the fixed electrode and diaphragm, internal stress that occurs on the diaphragm is eliminated. See at least Suzuki on [0021].
As to Claim 2, Chandrasekaran in view of Suzuki teaches the limitations of Claim 1, and wherein: the back-plate (240, 1002 Figure 2, 10a)comprises a back-plate electrode layer( 1022, [0079) disposed on a surface facing the vibration membrane( electrodes over or below the backplate 240 or 1002, 1001, [0079] the vibration membrane( diaphragm 220 or 1050 is formed on conductive material, [0035] is configured to be conductive, and a sound pressure signal is converted into an electric signal ( electrical signal generated in response to acoustic signal. See at least abstract) according to a change in a capacitance (capacitive MEMS transducer, [0035]) between the back-plate electrode layer (backplate 1002 having top bottom electrode 1022, Figure 10a) and the vibration membrane (diaphragm 1002). Also, see Suzuki abstract and [0040], a capacitor microphone is realized by combining a plate having a fixed electrode and a plurality of through holes, a diaphragm having a movable electrode, which vibrates in response to sound waves, and a spacer for supporting the plate and the diaphragm to be insulated from each other, thus forming an air gap between the fixed electrode and the movable electrode, wherein the diaphragm includes a first thin film and a second thin film that is attached onto the surface of the first thin film and whose internal stress differs from internal stress of the first thin film, and wherein a multilayered structure whose periphery is completely fixed is formed using the first and second thin films.
As to Claim 3, Chandrasekaran in view of Suzuki teaches the limitations of Claim 1 and Chandrasekaran further teaches wherein the vibration membrane ( 220) comprises: a corrugation portion(222) disposed within a range of the air chamber (213); and a bent portion( center convex portion of diaphragm 220, Figure 2) located radially inside the corrugation portion ( 222), and located closer to the back-plate ( 240) in comparison with a part of the vibration membrane (Figure 2) radially outside the corrugation portion (222), [0041] teaches atmospheric air exerts a force on each of the first and second diaphragms 220 and 230 in a direction towards the backplate 240. Since the corrugations 222 and 232 protrude outwards from the diaphragms 220 and 230, the atmospheric pressure acting on the corrugations 222 and 232 causes the corrugations to flex axially inwards towards the back plate 240 and radially outwards. This causes a decrease in the tension of diaphragm and an increase in compliance which increases proportionally with a relative increase in atmospheric pressure.
Claims 4-9 are rejected under 35 U.S.C. 103 as being unpatentable over Chandrasekaran et al. (US20210204048A1) in view of Suzuki (US 20070121972) in further view of Stojanovic et.al. (US20210392438A1).
As to Claim 4, Chandrasekaran teaches the limitations of Claim 3, and regarding the following: wherein the corrugation portion has a circular or polygonal shape having a predetermined size centered at a center of the air chamber, Chandrasekaran teaches convex corrugation portions 222 but does not explicitly teach the corrugation has a circular or polygonal shape. However, corrugations on the vibrating diaphragm having predetermined shape or size is well-known in the art. However, Stojanovic in related field (MEMS acoustic transducer) teaches on [0060] [0060] The corrugations of the corrugated diaphragm 202 can have any of a variety of configurations. For instance, the corrugated diaphragm 202 can have one or more concentric corrugations, e.g., centered substantially around the center of the membrane. The corrugations can be circular, oval, hexagonal, octagonal, or other shapes. In some examples, the shape of the corrugations can correspond to the shape of the diaphragm; in some examples, the corrugations can have a shape that is different from the shape of the diaphragm. The corrugations can have smooth cross-sectional profiles (e.g., substantially sinusoidal profiles) or stepped profiles. In some examples, the profile of the corrugations can vary at different points on the diaphragm, e.g., the profile of the corrugations can vary between the edge of the diaphragm and the center of the diaphragm. It would have been obvious to one of ordinary skill in the art, before the effective filing date of the invention to modify the shape of the corrugations Chandrasekaran to desired shape or size such as circular or polygonal to achieve desired rigidity of the diaphragm.
As to Claim 5, Chandrasekaran in view of Suzuki in further view of Stojanovic teaches the limitations of Claim 3, and wherein a distance between the back-plate (240) and the bent portion (center convex portion of diaphragm 220, Figure 2) of the vibration membrane (diaphragm 220) is smallest at a center of the bent portion (Figure 2), and the farther from the center of the bent portion, (center convex portion of diaphragm 220, Figure 2) the larger the distance.
As to Claim 6, Chandrasekaran in view of Suzuki in further view of Stojanovic teaches the limitations of Claim 3, Chandrasekaran further teaches and wherein the vibration membrane (diaphragm 220, Figure 2) is configured to support the bent portion toward the back-plate (240) by the compressive residual stress of the vibration membrane (implicit to diaphragm 220 of the MEMS transducer to prevent the diaphragm 220 to deform, [0042]).
As to Claim 7, Chandrasekaran in view of Suzuki in further view of Stojanovic teaches the limitations of Claim 3, and wherein the bent portion (center convex portion of diaphragm 220, Figure 2) is bent toward the back-plate electrode layer (backplate 240 having electrodes on top and bottom) by applying a preset bending voltage between the back-plate( back plate 240) electrode layer and the vibration membrane(220) or as shown on Figure 10a, applying voltage 1040 between the back plate 1002 and vibration membrane 1050, Figure 10a.[0078]).
As to Claim 8, Chandrasekaran in view of Suzuki in further view of Stojanovic teaches the limitations of Claim 3, and regarding the following: wherein: a back-plate electrode pad is disposed in the back-plate electrode layer and a vibration membrane electrode pad is disposed in the vibration membrane,( [0164] and Figure 14B-15E teaches of Suzuki teaches the back plate 1010 is basically formed using a disk-like portion that is not fixed to an insulating film 1045 of a conductive film 1022. The diaphragm 1030 is formed using a first disk-like portion, which is not fixed to an insulating film 1043 of a first thin film 1032, and a second disk-like portion, which is not fixed to an insulating film 1045 of a second thin film 1014. Both of the first thin film 1032 and the conductive film 1022 both having the conduction property are composed of polycrystal silicon into which impurities are doped, whereby they form opposite electrodes of a parallel-plate capacitor.) in order to detect the capacitance between the back-plate electrode layer and the vibration membrane; and the bent portion is bent toward the back-plate by applying the preset bending voltage between the back-plate electrode pad and the vibration membrane electrode pad, Suzuki teaches upon application of a bias voltage between the back plate 2 and the diaphragm 3 by means of the bias voltage applying device 4, the diaphragm 3 is bent in a circular-arc shape in cross section as shown in FIG. 2 due to electrostatic attraction, wherein tensile stress caused by such a curvature of the diaphragm 3 is canceled by the inherently applied compressive stress, thus eliminating the internal stress applied to the diaphragm 3. This reduces the stiffness of the diaphragm 3 that is electrically attracted to the back plate 2. Since the diaphragm 3 is inherently applied with a relatively small value of compressive stress of about 0.4 MPa, the capacitor microphone A of the present embodiment needs a very low bias voltage (which is 5 V or less) to be applied thereto in order to realize electrostatic attraction of the diaphragm 3. [0143], Figure 2.
As to Claim 9, Chandrasekaran in view of Suzuki in further view of Stojanovic teaches the limitations of Claim 8, and regarding the following: wherein a first metal layer is disposed on the back-plate electrode pad as an electrode terminal, and a second metal layer is disposed on the vibration membrane electrode pad as an electrode terminal, Suzu ki teaches on [0164],the back plate 1010 is basically formed using a disk-like portion that is not fixed to an insulating film 1045 of a conductive film 1022. The diaphragm 1030 is formed using a first disk-like portion, which is not fixed to an insulating film 1043 of a first thin film 1032, and a second disk-like portion, which is not fixed to an insulating film 1045 of a second thin film 1014. Both of the first thin film 1032 and the conductive film 1022 both having the conduction property are composed of polycrystal silicon into which impurities are doped, whereby they form opposite electrodes of a parallel-plate capacitor. The second thin film 1014 is used to adjust internal stress of the diaphragm 1030 and is composed of an insulating material such as Si.sub.3N.sub.4. The second thin film 1014 is attached to the first thin film 1032 in proximity to the back plate 1010. Figures 14B-15E.
Conclusion
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/SUNITA JOSHI/Primary Examiner, Art Unit 2691