TW201132135A - Smart microphone array - Google Patents

Abstract

This invention is an integrated complementary metal oxide semiconductor (CMOS) fabrication process, wafer level packaging process and micro-electromechanical capacitive micro-microphone array design method. The array contains a number of different structures of the microphone which includes at least one directional microphone and one omni-directional microphone. This invention integrates omni-directional microphones into directional microphone by CMOS-MEMS process manufacturing technology. The original microphone chip can be transformed into one complete directional microphone or omni-directional microphone array structure through post-process; and then to combine it with a microcontroller (MCU) by using flip-chip packaging technology, it will become a smart microphone array which receives sound from specific directions and contain the feature of high noisy removal. Especially suitable for hearing aids, high-efficiency radio microphone, voice identification, and sound source positioning.

Description

201132135 post-process; and then to combine it with a microcontroller (MCU) by using flip-chip packaging technology, it will become a smart microphone array which receives sound from specific directions and contain the feature of high noisy removal. Aids, high-efficiency radio microphone, voice identification, and sound source positioning. IV. Designated representative map: (1) The representative representative of the case is: (2). (2) Brief description of the symbol of the representative figure: 1. Micro-microphone array chip 4. Microcontroller chip. 〇·100. 2. Annular bump 3. Metal cover 5. If there is a chemical formula in this case, please reveal the most A chemical formula capable of displaying the characteristics of the invention: 6. Description of the Invention: [Technical Field] The present invention relates to a method for fabricating a smart microphone array, and more particularly to a microphone that is highly directional using a packaging technique _. This wisdom, microphone _ has high directivity and silk noise, especially suitable for hearing aids, high-frequency microphone, voice recognition, sound source positioning and so on. . [Prior technology] In the current communication n material (four), the mobile phone and the microphone • the leading market of 201132135 key, generally cause the inconvenience in the timing, in the noisy environment can not clearly listen to the sound of the rider And the sounds that I made (4) are the secrets of the environment, so that the money is not clear, if the money is ambiguous _ can greatly enhance the traditional hand-age krona and over-recording, which will prompt people to use the mobile phone. Convenient for many. Moreover, if the sound resolution of the microphone _ can be greatly increased, and the processing of the subsequent algorithm is left, a highly sensitive language can be achieved:

Identification, these Wei _ is how to make wisdom. The wind has a directional effect and increase the sensitivity of the microphone. The traditional directional microphone is mainly the omnidirectional microphone on __, which uses the encapsulation method to form the arbitrarily arbitrarily arbitrarily _ hiding to achieve the direction recording effect, and then the directionality of the circuit on the circuit is directional, the required area and Larger size. If a single n, for example, an area of 2·5 mm*2.5 mm, accommodates more than two omnidirectional microphones, the riding sound is like a plane-transmitting ball that is not well known, so many directional microphones are not. On the wafer, because the sound emitted by human month b is usually within GHz to 1GKHz, assuming that the wavelength is about 34m to 0. 〇34m at room temperature, if you want to have a good design, the distance d must be Farther, at least greater than sixteenth of the wavelength - as shown in Figure 1 (a), otherwise the vibration of the film is the same amplitude, both synchronous signals, not delayed signals, can not reach the phase waveform delay Function, so the distance between each other should be as large as possible. The higher the discriminability, the more the microphone spacing is too close, the same signal will be recognized for the sound, and the circuit cannot be used to distinguish the sound source. Therefore, it is indeed necessary to propose an innovation. The design and manufacturing method is to reduce the volume of the pointing microphone with the face 201132135. Ximuyue's reference to domestic and foreign references, using micro-microphones made by MEMS process, the use of body-shaped micro-addition or face-type micro-enhancement, these two plus I technology has become almost all the necessary technology. Utilizing the current CM〇s original process 剌 _ 智慧 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦 麦Micro-electroforming technology can be called into the resonant cavity and sound (four) structure to achieve the function of a directional microphone, Φ which is not possible with traditional MEMS microphones. SUMMARY OF THE INVENTION The object of the present invention is to produce a wealthy g-type micro-microphone wafer, which realizes a directional microphone chip in a 2.5 χ 25-sided wafer size by using a unique CMOS process, wherein a directional microphone The principle of chip design is to use two different microphones to be placed on the same-crystal # to get different sounds. The signal 'number' is the main sound source and the background noise, and the two sounds cannot affect the non-corresponding microphone. As shown in 1(b), some microphones collect the sonar from above, while others collect the sound from the side or the rear to achieve the function of delaying the phase waveform. The two sounds are separately collected and passed to the microcontroller. Perform subsequent processing. The signal extracted by the above directional microphone chip is sent to the microcontroller chip for subsequent processing, and the sound can be subsequently processed by the microcontroller, and the main function is the 纟'S strong aligning effect and the sigma recognition function. Many methods can meet our requirements, such as: Independent Component Analysis (ICA), Phase Delay Beam Concentration (Delay 201132135 and Sum Beamforming), adaptive filters, etc., to adapt, explain... Jianyou _ Green (4) It is expected that the adaptive filter will adjust the miscellaneous deletion so that the round = nO, so our output signal: 0utput = e = d(n)_vfn, the waiter out y a yu), as shown in Figure l ( c) No, adaptation _ wave riding is not fixed, 岐 with the wheel's reference ^ number, the coefficient of change is adjusted by the error term e, if the round signal 2 expected signal v number statistics When the characteristic is unstable, the scale is obtained by the adaptive (four) wave device.

The solution must be constantly updated to the staff, so that you can get a good solution. The features and advantages of this design of the present invention are as follows: (1) The use of the fresh complementary recording semiconductor to reduce the crystal chip technology can complete the microphone itself. If the substrate is flipped, the microcontroller can achieve a single package system (system in Packaging, SIP) requirements. (2) The smart microphone array has high directivity and noise removal, and the single small unit can be widely used in communication products. [Embodiment] The present invention is a smart micro-microphone array production method. As shown in FIG. 2, the smart micro-microphone array is mainly composed of a micro-microphone array chip 1, an annular bump 2, a metal cover 3, a microcontroller chip 4, and a printed circuit board 5. The micro-microphone array wafer 1 is composed of an omnidirectional microphone 6, as shown in Fig. 3, and a directional microphone 7, as shown in Fig. 4. The structure of the omnidirectional microphone 6 is as shown in FIG. 3 201132135, which comprises a vibrating film 9 having side holes 8 and a back plate 11 having a plurality of vent holes, and a vibration chamber 12 between the vibrating film 9 and the back plate u. . The directional microphone 7 has a structure as shown in Fig. 4, which includes a _9 and a back plate 11 having a plurality of vent holes, and a vibration chamber 12 between the vibrating film 9 and the back plate u. Micro-microphone array chip 1 design principle: the omnidirectional microphone 6 wants to receive sound, must act on the vibrating film 9, and the directional microphone 7 wants to receive sound, it must act on the vibration _ 9 'design omnidirectional microphone 6 In the radio direction*, the radio is received above, and the directional microphone 7 receives the radio signal from below, so the omnidirectional microphone 6 and the directional microphone 7 will have different audio signals. The manufacturing method can be completed by a CMOS post process or a MEMS process. The CMOS post-process is as follows: Step-: Design the layout of the micro-microphone array chip through a standard semiconductor process, as shown in Figure 5 (8), the layout of the micro-microphone array chip, taking 〇. 35 um as an example, omnidirectional The microphone 6 uses the Metal-1 layer as the vibration film φ 9, VIA-1 as the vibration chamber 12 'Metal-2, VIA-2, Metal-3, VIA-3, Metal-4 and the like as the back sheet 11. The directional microphone 7 uses the Metal-4 layer as the vibrating film 9, and the VIA-3 as the vibrating chamber 12, the metal~l' VIA-1' Metal-2, VIA-2, Metal-3 and the like as the back sheet 11. Step 2: After the surface of the die is spin-coated with a layer of photoresist 13, the exposure and development are defined to define the pattern 're-use of anisotropic remnant (such as: RIE) to oxidize; the δ 夕 14 button is finished, as shown in Figure 5 ( b) shown. 201132135 Step 3: Using the isotropic side solution (eg Silox Vap〇x m) side oxygen cut μ, make the vibration chamber 12, as shown in Figure 5 (c). Step 4: The front side of the crystal grain is adhered to her, and the back surface of the crystal grain is spin-coated with a photoresist 13 to perform a development process to define a pattern, and then an anisotropic engraving (eg, DRIE) is used. The substrate 15 is etched to a desired depth to complete the micro-microphone array wafer 1' as shown in Figure 5(d). The venting opening 10 of the backing plate 11 may be disposed not at the same position as the hole 8 in the vibrating film 9. Generally, the side hole 8 on the vibrating film 9 has a diameter smaller than that of the vent hole 10 but more than the vent hole 1G, for example, The number of vent holes (1) is about ten or less. The MEMS fabrication method is as follows: Step-: The recording material I5 is cleaned, and after exposure and development is performed on the positive-coating-layer photoresist 13', and a conductive film 16 is deposited thereon, as shown in Fig. 6 (8). In the second step, after the front side of the wire and the upper layer photoresist 13, exposure and development are performed to define a pattern, and the upper-layer insulating layer 17 is deposited, as shown in Fig. 6(b). Step 3: After the front side of the miscellaneous material is spin-coated with the layer photoresist 13, the pattern is formed by exposure and development, and the upper-layer conductive film 16 is deposited, as shown in Fig. 6(c). Step 4: The front side of the financial substrate is spin-coated with a layer of photoresist 13 and then exposed to the shadow definition pattern and an insulating layer is deposited on the front side of the stone substrate, as shown in Fig. 201132135 6(4). Step 5: spin-coating the front side of the ruthenium substrate to perform the exposure development definition, and deposit the upper-layer conductive film 16 on the front side of the substrate, as shown in Fig. 6(e). Step 6: depositing an insulating layer 17 on the front side of the crucible substrate,

As shown in Fig. 6(e), step 6 (g) shows the step 8: after the back surface of the stone substrate is spin-coated with a layer of photoresist 13, the non-isotropic carving is used. The depth and pattern are shown in the figure. Step 8: Apply the front and side of the wire to the layer-resistance, and define the pattern on the back of the material for exposure and development, and then use an isotropic (10) solution (eg: Η3ρ〇4). Part of the conductive film 16 is removed, and the non-isotropic is used to remove part of the insulating layer 17, and the action is repeated to the desired depth, as shown in Fig. 6(i). The directional residue (eg, taking (6) removes part of the conductive _ 16 to form the vibrating cavity 12, completes the micro-microphone array wafer 丨' as shown in FIG. 6(j). Although the microphone structure disclosed in the above process is only one In simplified illustration, the vibrating membrane 9 may be a mechanism composed of at least a layer of metal and having residual stress relief, and a micro-hole array is provided thereon as a residual hole 8, and the diameter of the micro-hole 201132135 should be less than the number Micron, and smaller than the vent hole of the back plate, and the back plate u can be composed of multiple layers of metal and dielectric layer It is stacked and has a number of vents 1 to control the microphone damping. The micro-microphone array chip 1 is packaged in at least two ways: mode - as shown in Figure 7, the 'first' signal processing circuit can be integrated into the microphone array chip 1, also It can be directly integrated into the other-microcontroller (9) 4, and the two wafers are assembled by the printed circuit board 5. The electric φ output on the microcontroller "4 and the printed circuit board 5 can be wired. Connecting, and printing the corresponding sound cavity of the w18 ' _ micro-micro-scale (9) ,, while covering the two wafers with the metal cover 3 and surrounding the bottom of the cover with the printed circuit board 5 using the adhesive 20 sealing joint. As shown in FIG. 8, in order to reduce the area of the package, the micro-microphone array wafer 1 can be flip-chip laminated onto the other-microcontroller chip 4, in a flip-chip manner, including the signal-connected independent bumps 19, and the vibration cavity. The outer periphery is formed into an annular protrusion 2, and the ring-shaped convex block 2 can be broken into a sound hole 18, and its structure is as shown in Fig. 9. The independent convex block 2 and the annular convex block 2 are preferably set up in the micro control. On wafer 4. By printed circuit board $ will The two stacked wafers are assembled, and the electrical input and output contacts on the microchip wafer 4 and the printed circuit board 5 can be connected by wire bonding, and the metal cover 3 covers the two wafers and the periphery of the cover and the printed circuit. The plate 5 is sealingly joined by an adhesive 2 (), and a sound hole 18 is provided on a side portion of the metal cover 3. Note that the shape and size and size of the annular projection 2 described above can be designed according to practical applications. The isometric view of the array wafer 1 after bonding through the flip chip package is as shown in Fig. 1. 201132135 — J, ?: Set::::: Her film 1 can be proud of 2. The 5th monument === tone, This know-how is different after the nose has passed, and it can be said that a good and clear voice can be applied to voice recognition and Bluetooth headsets. [Embodiment 1] The smart microphone array of 2χ2, as shown in Fig. u (a), may be composed of an omnidirectional microphone 6 and three directional microphones 7, and the arrangement may be omnidirectional to the upper left corner. The directional microphone 6 can be placed in the upper right corner, the lower right corner, and the lower left corner. Or as shown in Figure η (b), consisting of two omnidirectional microphones 6 and two directional microphones 7. The omnidirectional microphone 6 can be placed in the upper left corner and the lower left corner. The directivity can be set in the upper right corner and the lower right corner. Microphone 7. Or as shown in FIG. 11(c), it can be composed of two omnidirectional microphones 6 and two directional microphones 7. The arrangement can be called the upper right corner and the lower right corner is an omnidirectional microphone 6, upper left corner, lower left corner. The corner is a directional microphone 7. [Embodiment 2] The 3X3 smart plastic microphone array, as shown in Fig. 12(4), is characterized in that an omnidirectional microphone 6 and eight directional microphones 7 are composed of 'an omnidirectional microphone 6 disposed at the center of the array, A directional microphone 7 can be placed in eight directions around the center. Or as shown in Figure 12 (b), the feature 201132135 is composed of five omnidirectional microphone 6 arrays, the upper left corner, and the upper right "microphone 7, which can be placed in the lower left corner and the lower right corner of the erect erection =: The two sides of the array center are directly above, directly below, right side, and the work side has a forked directional microphone 7. Recruited as four omnidirectional microphones / Θ (e) 7F 'its special package too - and five points The sexual microphone 7 consists of 'the center of the mother's side of the dig #, the lower left corner, the upper right corner of the directional microphone 6, in the upper left corner, 7. The angle, the lower right corner, the center pendulum set the directional microphone [Embodiment 3] = = gram array] as shown in Figure 13, the characteristics of the cross ^ king of the microphone 6 'the rest are directional microphones 7. [Figure simple description] Figure 1 microcontroller adaptive data structure schematic diagram 2 Schematic diagram of smart microphone arrayFig.3 Schematic diagram of omnidirectional microphone structureFig.4 Schematic diagram of directional microphone structureFig.5 Schematic diagram of micro-microphone array flow diagram of purchase-嶋 process manufacturingFig.6 Schematic diagram of micro-microphone array process of MEMS processFig.7 Smart microphone array chip Material side --10 a schematic perspective view of the micro-array of microphones of the microphone array of FIG. 8 smart chip package of FIG. 9 201132135 embodiment two schematic block diagram of an annular projection

Fig. 11 Schematic diagram of 2x2 smart microphone array Fig. 12 Schematic diagram of 3 X 3 smart microphone array Fig. 13 Schematic diagram of cross smart microphone array [Description of main components] 1. Micro microphone array wafer 11. Back plate 2. Annular bump 12. Vibration chamber 3. Metal cover 13. Photoresist 4. Microcontroller wafer 14. Oxide oxide 5. Printed circuit board 15. Tantalum substrate 6. Omnidirectional microphone 16. Conductive film 7. Directional microphone 17. Insulation layer 8 Etched hole 18. Sound hole 9. Vibrating film 19 independent bump 10. Vent hole 20 adhesive

Claims (1)

201132135 VII. Patent application scope: !.-Micro-microphone array W, with at least - omnidirectional wheat structure and at least - directional microphone structure, can be completed by CM 〇s process or (Shi Qing process, omnidirectional The microphone structure has its vibration _ at the top, and the back plate is at the bottom of the 'sound direction. The sound can directly act on the vibrating film to generate a signal, while the directional microphone structure has its back plate at the top and the vibrating film under the 'sound direction. For the lower part, the sound is generated on the lower axis of the county, and the signal can be generated. Since the omnidirectional microphone and the directional microphone have different sound directions, the signals between the two will not interfere with each other. According to the patent application, The micro-microphone array chip, the combination of the microphone arrays can be an omnidirectional wheat button and a pointing microphone. 3. The micro-microphone array chip described in the scope of claim ii is manufactured through a CMOS process as follows: (4) One: Design the micro-microphone array layout through the standard CM〇S semiconductor process. Wang Xiangsheng's microphone uses the first layer of metal as the vibration thin film. a film, a second layer of dielectric material as a sacrificial layer or a thin layer, a second layer of metal to a top layer of metal or the like as a backing plate; and a directional microphone using the uppermost layer of metal as a vibrating film, and the next layer of dielectric material As a sacrificial layer or a vibrating cavity, a multi-layered layer between the metal layers of the metal thorns that are hidden is used as a backing plate; y. First, the front side of the crystal grains is spin-coated, and the photoresist is exposed, and the exposure is defined as a figure 201132135 Case 'Re-use anisotropic etching (such as: RIE) to etch the oxidized stone in the evening. · Step 2: Thorough isotropic (4) solution (such as: SibxVapoxIII) rotten oxidized stone, make a vibration cavity; Step 4: The front side of the die is adhered to the carrier, and the back side of the die is spin-coated with a photoresist. The pattern is defined by exposure development, and the germanium substrate is etched by anisotropic etching (eg, DRIE). The micro-microphone array wafer is completed to the desired depth. 4. The microphone array described in claim 1 is manufactured by the MEMS process as follows: Step 1: The ruthenium substrate is cleaned and applied to the ruthenium substrate. Apply a layer of photoresist to the front side After performing the exposure and development to define the pattern, a layer of conductive film is deposited on the surface; Step 2: spin the front surface of the germanium substrate with a layer of photoresist, perform exposure and development to define the pattern, and then deposit an insulating layer. Step 3 : Applying a layer of photoresist to the front side of the substrate, performing exposure and development to define a pattern, and then depositing a conductive film. Step 4: spin-coating the front surface of the substrate to a photoresist, and then performing exposure development to define After the pattern, and depositing an insulating layer on the front side of the germanium substrate; Step 5: spin coating the front side of the germanium substrate with a layer of photoresist, performing exposure development to define the pattern, and depositing a layer on the front side of the germanium substrate Conductive film; 201132135 Step 6: deposit the insulating layer on the front side of the germanium substrate; Step 7: spin the front side of the stone substrate to a layer of photoresist, define the exposure and development, and pattern and deposit on the front side of the germanium substrate. The upper conductive film is formed; Step 8: The back surface of the stone substrate is spin-coated with a layer of photoresist, and the pattern is defined by exposure and development, and then the anisotropic etching (eg, drie) is used to laminate the substrate. Inscribed to the desired depth and pattern. • (4) 9: Thorough isotropic (4), remove part of the conductive _ to form a resonant cavity, complete the micro-microphone array; Step 10: Join the upper-end guide post on the front of the microcontroller, And soldering the package guide post to the front side of the micro-microphone array; Step 11: Covering the micro-microphone array with a package cover having an opening, and the four sides of the package cover are joined above the micro-controller to complete the wisdom Type microphone array. 5. According to the micro-microphone array chip described in the third paragraph of the patent application, the amplification circuit can be further added to the _ CM0S process. 6. As claimed in the scope of the patent scope, the smart microphone _, the micro-microphone array is designed to use the microphone to obtain the sound signal, must be applied to the vibration diaphragm 'if the sound acts on the back panel, because the back The thickness of the plate is high, and the vibration is generated by the method, so the sound signal cannot be generated. The omnidirectional microphone is in the upper direction, and the line sound is generated by the feeder _ on the upper _, which generates a signal, 201132135 = directional microphone is in the direction of the sound Below, the t-view sound is introduced from below to act on the vibrating film below it to generate a signal; vice versa. 7. A smart microphone array, comprising: a micro-Mike shun film, having at least an omnidirectional mic structure and at least one 麦克风 microphone structure, the combination of which can be arbitrarily arranged for the omnidirectional microphone and the directional microphone, Through the CM0S process or process; than the audio signal into filtering noise and adding a microcontroller chip, the digital signal received by the micro-microphone array can be processed by internal algorithms and signals to achieve a strong signal ratio; A printed circuit board assembles the two wafers, and the electrical output contact point on the microchip wafer and the printed circuit board line can be connected by wire bonding, and a sound hole is arranged at the bottom of the printed circuit board to connect the microphone array chip. The corresponding sound chamber; the package cover, the micro-microphone array chip, the micro-controller chip, the periphery of the cover is covered with the enamel, and the JL is opened above the package cover - the small hole closes the sound A stream of people or a mixture of micro-microphones. According to the microphone array described in claim 7, the amplifying circuit can be further added by using the cm〇§ process. 9. A smart microphone array comprising: a micro-microphone array chip having at least one omnidirectional microphone structure and at least one directional microphone structure' combination of omnidirectional microphones and directional microphones arbitrarily arranged, CM 〇s process or micro-electromechanical (^乂 2011 2011 201132135 completed; - microcontroller chip, can convert the analog audio signal received by the micro-microphone array into a digital signal' and processed by detailed algorithm and _ _ over _ And the enhanced signal-to-noise ratio; at least one series of metal buttons, set on the surface of the micro-control (four) ^, can be connected with the analog signal soldering of the micro-microphone array chip in a flip chip manner; - a ring-shaped metal guide column, set in the micro Controlling (4) the surface of the wafer and combining it with the micro-microphone array wafer ring pad, the annular metal pillar is provided with a notch 'can be introduced into the background noise or derived; - the printed circuit board is to apply the above two laminated wafers Assembly, micro-control (4) The electrical input and output contacts on the wafer and the printed circuit board can be connected by wire bonding; a package cover, covering the micro-micro array The column wafer and the micro-controller chip are sealed and bonded to the printed circuit board by using an adhesive around the bottom of the cover, and a plurality of small holes are formed above and on the side of the package cover to facilitate sound inflow or airflow to release the micro-Mike Array 10. According to the smart microphone array described in claim 9, the amplifier circuit can be further added to the CMOS process.