Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
  • H04R19/00—Electrostatic transducers
  • H04R19/005—Electrostatic transducers using semiconductor materials
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B81—MICROSTRUCTURAL TECHNOLOGY
  • B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
  • B81B7/00—Microstructural systems; Auxiliary parts of microstructural devices or systems
  • B81B7/0032—Packages or encapsulation
  • B81B7/0077—Other packages not provided for in groups B81B7/0035 - B81B7/0074
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
  • H04R19/00—Electrostatic transducers
  • H04R19/01—Electrostatic transducers characterised by the use of electrets
  • H04R19/016—Electrostatic transducers characterised by the use of electrets for microphones
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
  • H04R31/00—Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B81—MICROSTRUCTURAL TECHNOLOGY
  • B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
  • B81B2201/00—Specific applications of microelectromechanical systems
  • B81B2201/02—Sensors
  • B81B2201/0257—Microphones or microspeakers
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
  • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
  • H01L2224/42—Wire connectors; Manufacturing methods related thereto
  • H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
  • H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
  • H01L2224/4805—Shape
  • H01L2224/4809—Loop shape
  • H01L2224/48091—Arched
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
  • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
  • H01L2224/42—Wire connectors; Manufacturing methods related thereto
  • H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
  • H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
  • H01L2224/481—Disposition
  • H01L2224/48151—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
  • H01L2224/48221—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
  • H01L2224/48225—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being non-metallic, e.g. insulating substrate with or without metallisation
  • H01L2224/48227—Connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being non-metallic, e.g. insulating substrate with or without metallisation connecting the wire to a bond pad of the item
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L23/00—Details of semiconductor or other solid state devices
  • H01L23/552—Protection against radiation, e.g. light or electromagnetic waves
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
  • H01L2924/01—Chemical elements
  • H01L2924/01004—Beryllium [Be]
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
  • H01L2924/01—Chemical elements
  • H01L2924/01078—Platinum [Pt]
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
  • H01L2924/10—Details of semiconductor or other solid state devices to be connected
  • H01L2924/146—Mixed devices
  • H01L2924/1461—MEMS
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
  • H01L2924/15—Details of package parts other than the semiconductor or other solid state devices to be connected
  • H01L2924/161—Cap
  • H01L2924/1615—Shape
  • H01L2924/16152—Cap comprising a cavity for hosting the device, e.g. U-shaped cap
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
  • H01L2924/15—Details of package parts other than the semiconductor or other solid state devices to be connected
  • H01L2924/161—Cap
  • H01L2924/163—Connection portion, e.g. seal
  • H01L2924/16315—Shape
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
  • H01L2924/19—Details of hybrid assemblies other than the semiconductor or other solid state devices to be connected
  • H01L2924/1901—Structure
  • H01L2924/1904—Component type
  • H01L2924/19041—Component type being a capacitor
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
  • H01L2924/30—Technical effects
  • H01L2924/301—Electrical effects
  • H01L2924/3025—Electromagnetic shielding
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
  • H04R2499/00—Aspects covered by H04R or H04S not otherwise provided for in their subgroups
  • H04R2499/10—General applications
  • H04R2499/11—Transducers incorporated or for use in hand-held devices, e.g. mobile phones, PDA's, camera's

Definitions

• the present invention relates to a shield case that covers a MEMS chip using a micromachining technology that utilizes semiconductor technology.
• the present invention also relates to a MEMS microphone, and more particularly to a MEMS microphone including a shield case.
• shield cases have been used to protect electronic components such as chips mounted on a substrate from external electromagnetic noise or dust.
• FIG. 6 shows an external perspective view of a conventional MEMS microphone.
• Figure 7 (a) is a side view of a conventional MEMS microphone.
• Figure 7 (b) is a plan view of a conventional MEMS microphone.
• Fig. 7 (c) is a vertical cross-sectional view of the conventional MEMS microphone (cross-sectional view taken along the line AA in Fig. 6).
• a conventional MEMS microphone 300 shown in FIGS. 6 and 7 includes a substrate 301, a MEMS chip 200, and a shield case 303.
• the MEMS chip 200 is a chip that converts sound signals into electrical signals.
• Such a MEMS microphone 300 is used by being mounted on a main substrate of a mobile phone or the like, for example.
• the microphone sound hole of the mobile phone casing and the sound hole 303c on the top plate 303a of the shield case are arranged and mounted.
• the sound holes are arranged at approximately the same position, if there is a gap between the housing and the shield case 303, the sound signal will leak from the gap and the pre-designed acoustic characteristics will change. May end up.
• a device has been devised to eliminate the gap by closely attaching a gasket made of a material such as rubber or silicon between the top plate 303a of the shield case and the casing of the mobile phone.
• Patent Document 1 Japanese Patent Application Laid-Open No. 2005-354377
• a chucking area S for picking and placing the MEMS microphone 300 on the top board 303a.
• This chucking area S has a certain area while avoiding the sound hole 303c on the top plate 303a of the shield case that prevents the failure of the MEMS chip 200 as shown in FIG. 7 (b).
• the MEMS microphone 300 be disposed near the center of gravity of the shield case in the chucking area S, that is, near the center of the top plate 303a.
• the MEMS microphone 300 has been required to be further reduced in size and thickness, and accordingly, the shield case 303 has been reduced in size and thickness. Along with this, the area of the top plate 303a of the shield case has also been reduced, making it difficult to secure the area where the gasket is in close contact while securing the arrangement and area of the chucking area S on the top plate. I came.
• the chucking area S should have at least a vertical X horizontal 1.2 mm] XI .2 [mm] area in terms of the weight of the shield case and the performance of the chuck device. Further, as shown in FIG. 7 (b), the chucking area S must be located as close as possible to the center position of the top plate 303a of the shield case. [0013] Further, in order to ensure airtightness by sandwiching the gasket, it is necessary to secure at least l [mm] or more for each distance LI′L2 from the sound hole 303c to the end of the top plate 303a. It is desirable to secure this distance as long as possible from the viewpoint of airtightness.
• the shield case 303 is also being uniformly thinned to the extent that the strength as a structure can be secured.
• the top plate 303a And the wall thickness S of the side plate 303b are 0.1 l [mm].
• the shield case that has been thinned in this way is lighter and has a shape that makes it difficult for solder to attach due to the reduced size of the end of the force side plate, which can increase the height and width of the inner frame. In other words, the adhesive strength with the substrate will be weak if it is fixed by simply soldering the end.
• the conventional shield case having a uniform and thin shape is provided with a bent portion 303d at the end of the side plate 303b, thereby providing a space in which an appropriate amount of solder is accumulated. ing.
• a solder fillet 303e is formed in the space formed by the bent portion 303d to obtain a bonding strength.
• the shield case 303 that is uniformly thinned as described above must be sized to fit within the substrate 301 including the bent portion 303d, and the top plate is provided by the amount of the bent portion 303d. The size of 303a was reduced.
• the conventional shield case is usually formed by drawing, and has a shape (a shape with rounded corners) having a bent portion 303f force formed by the end portion of the top plate 303 and the side plate 303b.
• the shape of the flat part of the top plate could not be secured to the maximum.
• the present invention has been made in view of the above-described problems, and does not change the position / size 'range of the chucking area on the top plate of the shield case, that is, the area / arrangement of the chucking area.
• the object is to provide a shield case and a MEMS microphone having the shield case that can ensure a minimum distance on the top plate that is in close contact with the gasket.
• the shield case of the present invention is a shield case that shields the MEMS chip mounted on the substrate from the outside, and includes a top plate and a plurality of side plates, and the thickness f of the plurality of side plates f It is thicker than the thickness of the board.
• the bent portion formed by the end portion of the top plate and the side plate has a corner.
• the shield case of the present invention can be formed so as to have corners by, for example, punching in a press die.
• the bent portion formed by the end portion of the top plate and the side plate can have an R of 0.05 or less, thereby sufficiently expanding the area of the flat portion of the top plate. The ability to improve close contact life is also possible.
• end portions of the plurality of side plates have an R-shaped portion toward the inside of the shield case.
• solder enters the space portion of the R-shaped portion and a solder fillet is formed, so that the force S can be firmly fixed to a substrate or the like with an appropriate amount of solder. . It is desirable that the R-shaped portion be 0.1 or less. The space formed by the R-shaped portion can hold sufficient solder.
• the MEMS microphone of the present invention is a shield case that shields the MEMS chip from an external force with a substrate, a MEMS chip mounted on the substrate, and a top plate and a plurality of side plates.
• the area of the top plate of the shield case can be increased compared to a conventional shield case having a uniform thickness. Therefore, secure a long distance to keep the gasket in close contact with the top plate without changing the position and size of the chucking area from the conventional one.
• the MEMS microphone of the present invention has a bent portion force and a corner formed by an end portion of the top plate of the shield case and the side plate.
• the force S is used to increase the area of the flat portion of the top plate of the shield case that covers the MEMS chip.
• the end portions of the plurality of side plates have an R-shaped portion toward the inner side of the shield case.
• solder enters the space portion of the R-shaped portion to form a solder fillet, so that the substrate and the shield case are firmly fixed with an appropriate amount of solder.
• the area of the top plate of the shield case can be increased, so that the gasket without changing the position, size, range, etc. of the chucking area from the conventional one is brought into close contact with the top plate. An area can be secured.
• FIG. 1 is an external perspective view of MEMS microphone 100 according to the first embodiment.
• FIG.4 External perspective view of mobile phone 150 equipped with MEMS microphone 100
• FIG. 7 (a) Side view of a conventional MEMS microphone, (b) Plan view of a conventional MEMS microphone, (c) Longitudinal section of a conventional MEMS microphone (cross section of A-A spring in Fig. 6) Explanation of symbols
• FIG. 1 is an external perspective view of the MEMS microphone 100 according to the first embodiment.
• FIG. 2 shows a longitudinal sectional view of MEMS microphone 100 (a sectional view taken along line BB in FIG. 1).
• the MEMS microphone 100 has a substrate 101, a MEMS chip 102, and a shield case 103, and the thickness of the side plates 103b constituting the shield case 103 is as follows. It is characterized by being thicker than the thickness of the top plate 103a.
• the substrate 101 is a printed board on which the MEMS chip 102 is mounted.
• the dimensions of the mounting surface of the substrate 101 are, for example, vertical X horizontal 3 [mm] X 4 [mm].
• the MEMS chip 102 converts a sound signal captured by the diaphragm electrode 43 into an electrical signal.
• the MEMS chip 102 has a vibrating membrane electrode 43 and an electret film 44 on a silicon substrate 41 with a first insulating layer 42 interposed therebetween.
• a fixed electrode 46 having a sound hole 47 is formed through an insulating layer 45.
• a back air chamber 55 is formed on the back surface of the vibrating membrane electrode 43 by etching the silicon substrate 41.
• MEMS Micro Electro Mechanical System
• MEMS Micro Electro Mechanical System
• the vibrating membrane electrode 43 is made of conductive polysilicon
• the electret film 44 is made of a silicon nitride film or a silicon oxide film
• the fixed electrode 46 is made of conductive polysilicon or silicon oxide.
• a film or a silicon nitride film is laminated.
• an amplifier circuit 48 that amplifies the electric signal of the MEMS chip 102 is electrically connected by a wire 49.
• the MEMS chip 102 and the amplifier circuit 48 are covered with a shield case 103.
• FIG. 3 (a) is a side view of the MEMS microphone 100.
• FIG. FIG. 3B is a plan view of the MEMS microphone 100.
• Fig. 3 (c) is a cross-sectional view taken along the line CC in Fig. 3 (b).
• Fig. 3 (d) is a cross-sectional view taken along the line DD in Fig. 3 (b). Note that the MEMS chip 102 is not shown in each drawing of FIG.
• the shield case 103 includes a top plate 103a having a substantially rectangular shape with rounded corners.
• the material of the shield case is, for example, a metal material having an electrical shield such as white (alloy made of copper, lead, nickel), Kovar, 42 alloy.
• the shield case may be subjected to a surface treatment such as Ni plating in order to obtain bonding with the substrate by soldering or the like.
• the thickness of the top plate 103a is 0.1 [mm]
• the thickness of each of the side plates 103b is 0.25 [mm]. That is, the shield case 103 has an uneven thickness structure in which the side plate 103b is thicker than the top plate 103a. Further, the end portion 103f of the top plate 103a is formed in a shape having a corner.
• the shield case 103 can be formed, for example, in a shape having corners by punching in a press die.
• R was 0.05 or less.
• R was 0.2 or less. This corner shape is good if it has a small R (small roundness) compared to the corner shape of the bent part formed by conventional drawing.
• the bent portion formed by the end portion of the top plate and the side plate as in the conventional shield case has a relatively large shape with a corner, that is, R is small. Since it has a shape with a bent portion, the flat part of the top plate expands by the thickness of the side plate. Furthermore, the area of the top plate increases as the thickness of the side plate increases. Therefore In the design of the top plate of the shield case, it is possible to secure an area where the gasket is in close contact and a chucking area.
• the top plate 103a of the shield case of the first embodiment has a sound hole 103c having a diameter of 0.6 [mm].
• a chucking area S is secured at a position that does not overlap with the sound hole 103c.
• the chucking area S is vertical X horizontal 1.2 [mm] X 1 .2 [mm], and the center of the chucking area S is arranged near the center position of the top plate 103a of the shield case.
• the shield case is made by unevenly machining a single plate and performing shape processing in the press die, and by punching out in the press die, the side plate is thicker than the top plate. It is formed so that R becomes smaller with increasing thickness.
• the side plate 103b of the shield case is formed at the end of each side of the rectangular top plate 103a.
• the shield case 103 includes a top plate 103a and four side plates 103b, and has a substantially rectangular lid shape.
• the end portion of the side plate 103b is processed to have an R-shaped portion 103d toward the inside of the shield case 103.
• solder enters the space of the R shape 103d to form the solder fillet 103e. It can be firmly fixed with an appropriate amount of solder. Conventionally, it was about 0.15, and the space of R shape 103d was not enough to hold enough solder, whereas this R shape part was 0.1 or less, so R shape 103d Space can hold enough solder.
• the force described as the shape of the shield case being a rectangular lid shape is not limited to this, and may be deformed along with the shape of the substrate. .
• the top plate of the shield case 103 should be circular.
• the top plate of the shield case 103 is also polygonal. You can do it.
• FIG. 4 is an external perspective view of a mobile phone 150 on which the MEMS microphone 100 is mounted.
• FIG. 5 is a cross-sectional view of the main part in the vicinity of the microphone portion of mobile phone 150 (a cross-sectional view taken along the line EE in FIG. 4).
• a sound hole 152 for a microphone is formed in a case 151 of the mobile phone 150 shown in FIG. 4 at a position near the user's mouth when in use.
• a gasket 154 is sandwiched between the top plate 103 a of the shield case of the MEMS microphone 100 and the inner surface of the housing 151.
• this shield case 103 is also characterized in that the thickness S of the side plate 103b and the thickness of the top plate 103a are thicker.
• the sound hole 152 of the casing 151 and the sound hole 103c of the shield case have substantially the same shape, and are formed so that the sound holes overlap after assembly.
• the gasket 154 has a hole 154a having substantially the same shape as the sound hole 103c.
• an acoustic resistance material 154b is formed at the end of the hole 154a on the housing side. This acoustic resistance material 154b reduces the propagation speed of the sound signal, and here, functions to adjust the acoustic characteristics of the MEMS microphone 100.
• the thickness of the gasket 154 is a little thicker than the gap between the top plate 103a and the inner surface of the casing 151, and is sandwiched between the sound hole 103c of the shield case and the end of the top plate 103a. ing.
• the distance L1'L2 from the sound hole 103c of the shield case to each end of the top plate 103a is designed to have an interval of l [mm] or more. Airtightness after sandwiching the gasket 154 is ensured.
• the sound signal entering from the sound hole 152 of the casing does not leak into the gap between the top plate 103a and the inner surface of the casing 151, and the acoustic characteristics of the MEMS microphone 100 are not impaired.
• the sound that has entered from the sound hole 152 of the casing passes through the acoustic resistance material 154b and propagates to the diaphragm electrode 43 of the MEMS chip.
• the capacitance of the flat plate capacitor composed of the diaphragm electrode 43 and the fixed electrode 46 changes, and is taken as the voltage change between the diaphragm electrode 43 and the fixed electrode 46. It is ejected.
• the MEMS microphone 100 can solve the problem of sound leakage due to the gasket because the area of the top plate is enlarged by making the shield case 103 have an uneven thickness structure. Accordingly, since the miniaturized MEMS microphone 100 can be mounted on a mobile phone, the overall shape of the mobile phone 150 contributes to a smaller and thinner shape.
• the shield case 103 has a side wall thickness that is thicker than the top plate, the position of the center of gravity is more stable than that of a shield case having a uniform thickness. Accordingly, in the assembly process, when the chucking area S of the shield case 103 is attracted by the chuck device and the MEMS microphone 100 is transported, the force S can be stably transported. That is, the process of carrying the MEMS microphone 100 to the mounting position of the main board 155 of the mobile phone 150 can be stably and reliably performed.
• the area of the top plate of the shield case can be expanded, a region for closely adhering the gasket to the top plate without changing the position / size 'range of the chucking area from the conventional one is provided. It is useful as a shield case that can be secured and as a MEMS microphone.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Acoustics & Sound (AREA)
• Signal Processing (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Manufacturing & Machinery (AREA)
• Computer Hardware Design (AREA)
• Details Of Audible-Bandwidth Transducers (AREA)
• Micromachines (AREA)

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Related Child Applications (1)

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• 2006
  • 2006-09-15 JP JP2006250915A patent/JP4387392B2/ja not_active Expired - Fee Related
• 2007
  • 2007-09-13 WO PCT/JP2007/067846 patent/WO2008032785A1/ja not_active Ceased
  • 2007-09-13 CN CNA2007800041936A patent/CN101379869A/zh active Pending
  • 2007-09-13 US US12/160,663 patent/US7904123B2/en active Active
• 2011
  • 2011-01-26 US US13/014,340 patent/US20110116661A1/en not_active Abandoned

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