MEMS microphone

Abstract

A MEMS microphone according to one embodiment of the present invention comprises: a first substrate; a second substrate stacked on the first substrate; a MEMS structure disposed on the second substrate; and a capacitor spaced apart from the MEMS structure and disposed on the second substrate, wherein the second substrate includes at least one hole, and the capacitor is electrically connected to the first substrate through a wire passing through the hole of the second substrate.

Description

MEMS Microphone

[0001] The present invention relates to a MEMS microphone, and more specifically, to a MEMS microphone using a COF.

[0002] Typically, audio devices use electrodes to vibrate a diaphragm to generate sound. Recent technological advancements have led to significant advancements in the audio device field. These devices are increasingly used in diverse applications, including portable terminals and hearing aids. As the devices they are used in become slimmer, the devices themselves are also becoming smaller.

[0003] Additionally, microphones utilizing MEMS (Micro Electro Mechanical Systems), a semiconductor technology, have recently been developed and used. MEMS is a technology that enables the manufacturing of tiny mechanical components on the surface of silicon wafers. These MEMS microphones can be categorized into electrostatic and piezoelectric types, including the common condenser type.

[0004] Recently, electronic devices such as mobile communication terminals, tablet PCs, and MP3 players are becoming increasingly miniaturized. Consequently, the components of these devices are also becoming smaller. Therefore, Micro Electro Mechanical System (MEMS) technology is needed to overcome the physical limitations of these components.

[0005] The technical problem to be solved by the present invention is to provide a MEMS microphone using COF.

[0006] In order to solve the above technical problem, a MEMS microphone according to one embodiment of the present invention includes a first substrate; a second substrate laminated on the first substrate; a MEMS structure disposed on the second substrate; and a capacitor disposed on the second substrate and spaced apart from the MEMS structure, wherein the second substrate includes one or more holes, and the capacitor is electrically connected to the first substrate through a wire passing through the hole of the second substrate.

[0007] Additionally, the hole of the second substrate may include a first hole through which a wire connecting the capacitor and the first substrate passes; and a second hole corresponding to the lower portion of the MEMS structure.

[0008] Additionally, the hole of the second substrate may be formed at a predetermined distance from the outer edge of the second substrate.

[0009] Additionally, a conductive adhesive layer may be included between the first substrate and the second substrate, and the conductive adhesive layer may include a hole overlapping with a hole of the second substrate.

[0010] Additionally, the area of ​​the hole of the conductive adhesive layer may be larger than the area of ​​the hole of the second substrate.

[0011] Additionally, the first substrate may include a connection pad positioned at a position corresponding to the bottom of the hole of the second substrate.

[0012] In addition, the device includes an ASIC module disposed on the second substrate and spaced apart from the MEMS structure, and the ASIC module can be electrically connected to the first substrate through a wire passing through a hole in the second substrate.

[0013] Additionally, the ASIC module can be electrically connected to the MEMS structure and the capacitor via wires, respectively.

[0014] Additionally, the first substrate may be a flexible substrate, and the second substrate may be a rigid substrate.

[0015] Additionally, the first substrate and the second substrate can be bonded by thermocompression.

[0016] In order to solve the above technical problem, a MEMS microphone according to a second embodiment of the present invention includes: a first substrate; a second substrate laminated on at least one area of ​​the first substrate; a MEMS structure and a signal processing element disposed on the second substrate; a first capacitor laminated on the first substrate on which the second substrate is not laminated; and a second capacitor laminated under the signal processing element.

[0017] Additionally, the first electrode of the second capacitor may be electrically connected to the first substrate, and the second electrode of the second capacitor may be electrically connected to the second substrate.

[0018] Additionally, the first electrode of the second capacitor may be disposed at the lower portion of the second capacitor and soldered to the first substrate.

[0019] In addition, the second capacitor may include a conductive adhesive layer electrically connecting the second capacitor and the second substrate on top of the second capacitor; and a non-conductive adhesive layer laminated between the conductive adhesive layer and the signal processing element.

[0020] Additionally, the second substrate may include an etching region in an area where the second capacitor is placed.

[0021] Additionally, the signal processing element can be connected to the MEMS structure and the first substrate by wires, respectively.

[0022] In order to solve the above technical problem, a MEMS microphone according to another embodiment of the second embodiment of the present invention includes: a first substrate; a second substrate laminated on at least one area of ​​the first substrate; a housing covering the second substrate; a MEMS structure disposed on the second substrate; a first capacitor disposed on the second substrate and spaced apart from the MEMS structure; and a second capacitor laminated below the first capacitor.

[0023] Additionally, the first electrode of the first capacitor may be positioned on the second capacitor, and the second electrode of the first capacitor may be positioned on the second substrate.

[0024] Additionally, the first electrode of the second capacitor may be electrically connected to the first electrode of the first capacitor, and the second electrode of the second capacitor may be electrically connected to the first substrate.

[0025] Additionally, the second substrate may include an etching region in an area where the second capacitor is placed.

[0026] In addition, the first capacitor may include a metal portion laminated on the lower portion thereof, and the first electrode of the first capacitor may be positioned on the second capacitor, and the second electrode of the first capacitor may be positioned on the metal portion.

[0027] Additionally, the first electrode of the first capacitor may be connected to the first substrate by a wire.

[0028] In addition, the second substrate includes a half-etched region in which the metal portion and the second capacitor are arranged, and the thickness of the half-etched region may be thinner than the thickness of other regions.

[0029] Additionally, the third capacitor may be stacked on the lower portion of the first capacitor, and the first electrode of the first capacitor may be positioned on the second capacitor, and the second electrode of the first capacitor may be positioned on the third capacitor.

[0030] Additionally, the second electrode of the first capacitor may be electrically connected to the first electrode of the third capacitor.

[0031] Additionally, the first electrode of the first capacitor may be connected to the first substrate by a wire.

[0032] In addition, the second substrate includes a half-etched region in which the second capacitor and the third capacitor are arranged, and the thickness of the half-etched region may be thinner than the thickness of other regions.

[0033] In order to solve the above technical problem, a MEMS microphone according to another embodiment of the second embodiment of the present invention includes: a first substrate; a second substrate laminated on at least one area of ​​the first substrate; a housing covering the second substrate; a MEMS structure disposed on the second substrate; a first capacitor disposed on the first substrate on which the second substrate is not laminated; a second capacitor laminated under a first electrode of the first capacitor; and a fourth capacitor laminated under a second electrode of the first capacitor.

[0034] Additionally, the first electrode of the second capacitor may be electrically connected to the first electrode of the first capacitor, the second electrode of the second capacitor may be electrically connected to the first substrate, the first electrode of the fourth capacitor may be electrically connected to the first substrate, and the second electrode of the fourth capacitor may be electrically connected to the second electrode of the first capacitor.

[0035] Additionally, the first electrode of the first capacitor may be connected to the first substrate by a wire.

[0036] In order to solve the above technical problem, a MEMS microphone according to a third embodiment of the present invention includes a first substrate; a second substrate laminated on at least one area of ​​the first substrate; a MEMS structure and a signal processing element disposed on the second substrate; and a capacitor element laminated on the first substrate on which the second substrate is not laminated, wherein the capacitor element includes a capacitor and an interposer laminated under the capacitor.

[0037] Additionally, the interposer includes an FR4 printed circuit board, and the capacitor can be surface-mounted on the printed circuit board.

[0038] Additionally, the interposer includes a metal plate, and the capacitor can be mounted on the metal plate.

[0039] In addition, the metal plate includes a first metal plate and a second metal plate, and the first metal plate and the second metal plate can form a bridge structure that is connected to both electrodes of the capacitor, respectively.

[0040] Additionally, the interposer may include any one of an FR4 printed circuit board, a metal plate, a lead frame, a ceramic printed circuit board, and a metal printed circuit board.

[0041] Additionally, the capacitor element can be soldered onto the first substrate.

[0042] In addition, the capacitor element may be placed apart from the signal processing element, but may be electrically connected to it.

[0043] Additionally, the signal processing element may include an ASIC module.

[0044] Additionally, the first substrate may be a flexible substrate, and the second substrate may be a rigid substrate.

[0045] Additionally, the first substrate and the second substrate can be bonded by thermocompression.

[0046] In order to solve the above technical problem, a MEMS microphone according to a fourth embodiment of the present invention includes a first substrate; a second substrate laminated on at least one area of ​​the first substrate; a conductive adhesive layer laminated between the first substrate and the second substrate; an upper adhesive layer laminated on the second substrate; and a MEMS structure and a signal processing element disposed on the upper adhesive layer, wherein the MEMS structure is directly bonded to the upper adhesive layer, and the upper adhesive layer includes a coverlay or a photo solder resist.

[0047] In order to solve the above technical problem, a MEMS microphone according to another embodiment of the fourth embodiment of the present invention includes a first substrate; a first photo solder resist layer laminated on at least one area of ​​the first substrate; a second photo solder resist layer laminated on at least one area of ​​the first substrate; and a MEMS structure and a signal processing element disposed on the first photo solder resist layer, wherein the first substrate is directly bonded to the first photo solder resist layer and the second photo solder resist layer.

[0048] In order to solve the above technical problem, a MEMS microphone according to another embodiment of the fourth embodiment of the present invention comprises: a first substrate; a second substrate laminated on at least one area of ​​the first substrate; a conductive adhesive layer laminated between the first substrate and the second substrate; a MEMS structure and a signal processing element disposed on the second substrate; and a cover covering the second substrate, wherein the second substrate comprises: a base facing the first substrate; and a side plate extending upward from an outer surface of the base, wherein the cover is joined to an end of the side plate of the second substrate.

[0049] Additionally, the first substrate and the cover may be composed of the same material.

[0050] Additionally, the second substrate and the cover can be solder-joined.

[0051] Additionally, the first substrate may include a 2METAL COF substrate.

[0052] Additionally, the first substrate may be a flexible substrate, and the second substrate may be a rigid substrate.

[0053] Additionally, the second substrate may include any one of silver, SUS, ceramic, and FR4.

[0054] Additionally, it may include a capacitor that is placed on the second substrate and spaced apart from the signal processing element.

[0055] Additionally, the signal processing element may include an ASIC module.

[0056] In order to solve the above technical problem, a MEMS microphone according to a fifth embodiment of the present invention includes a first substrate; a second substrate laminated on at least one area of ​​the first substrate; a shield can bonded on the second substrate; and a MEMS structure and a signal processing element arranged on the second substrate in an internal space of the shield can, wherein the shield can is made of the same material as the second substrate.

[0057] Additionally, the second substrate and the shield can may be made of SUS or nickel silver.

[0058] In addition, the second substrate includes a mounting portion in which the shield can is placed in an area that is in contact with the shield can, and the thickness of the mounting portion of the second substrate may be thinner than the thickness of another area of ​​the second substrate other than the mounting portion.

[0059] Additionally, the shield can may include a top plate; a side plate extending downward from an outer edge of the top plate; and a lid portion extending outward from an end of the side plate.

[0060] Additionally, the shield can may include a top plate; a side plate extending downward from an outer surface of the top plate; and a plurality of protrusions extending downward from ends of the side plates and spaced apart from each other.

[0061] Additionally, the second substrate may not be laminated in an area corresponding to the protrusion of the shield can.

[0062] Additionally, the second substrate may be etched in an area corresponding to the protrusion of the shield can so that the end of the protrusion of the shield can can be bonded to the first substrate.

[0063] Additionally, the side surface of the protrusion connecting the end of the side plate of the shield can and the end of the protrusion, and the end of the side plate of the shield can can be bonded to the second substrate.

[0064] Additionally, epoxy or silicone that fills the step in the area where the shield can and the first substrate, and the shield can and the second substrate are bonded, can be bonded together with the shield can.

[0065] In addition, the top plate of the shield can has a rectangular shape, the side plate of the shield can includes first to fourth side plates extending from the top plate, and the plurality of protrusions can extend downward from the ends of the side plates along the shape of an edge at which two adjacent side plates among the first to fourth side plates are connected.

[0066] In order to solve the above technical problem, a MEMS microphone according to a sixth embodiment of the present invention includes a first substrate; a second substrate laminated on at least one area of ​​the first substrate; a housing bonded to the second substrate; and a MEMS structure and a signal processing element disposed on the second substrate in an internal space of the housing, wherein the second substrate includes an etching area in which the MEMS structure or the signal processing element is disposed, and a thickness of the etching area of ​​the second substrate is thinner than a thickness of another area of ​​the second substrate other than the etching area.

[0067] Additionally, when bonding the MEMS structure to the second substrate, epoxy or silicon may be applied within the etching area.

[0068] Additionally, the etching area of ​​the second substrate can be etched on a surface facing the first substrate to form a cavity.

[0069] Additionally, wiring electrically connected to the first substrate can be arranged in the cavity.

[0070] Additionally, the housing may include a capacitor that is spaced apart from the signal processing element and placed in the etched area of ​​the second substrate.

[0071] Additionally, the signal processing element may include an ASIC module.

[0072] Additionally, the first substrate may be a flexible substrate, and the second substrate may be a rigid substrate.

[0073] Additionally, the first substrate and the second substrate can be bonded by thermocompression.

[0074] In order to solve the above technical problem, a MEMS microphone according to another embodiment of the sixth embodiment of the present invention includes a first substrate; a second substrate laminated on at least one area of ​​the first substrate; a housing bonded on the second substrate; and a MEMS structure and a signal processing element disposed on the second substrate in an internal space of the housing, wherein the second substrate is not laminated on an area where the MEMS structure or the signal processing element is disposed.

[0075] In addition, the second substrate is not laminated in the area where one of the MEMS structure or the signal processing element is disposed, and the area where the other is disposed includes an etching area, and the thickness of the etching area of ​​the second substrate may be thinner than the thickness of another area of ​​the second substrate other than the etching area.

[0076] According to embodiments of the present invention, the process can be simplified and time can be shortened. In addition, the metal plate hole etching area can be reduced, which reduces the process management point, increases the design freedom for hole shape and size reduction, increases the capacitor capacity, and increases the attachment area of ​​the conductive adhesive layer, thereby preventing delamination and enhancing reliability.

[0077] According to embodiments of the present invention, multiple capacitors can be mounted, enabling the mounting of capacitors for power supply noise removal and RF noise removal. Furthermore, capacitors for power supply noise removal for DVdd and power supply noise removal for AVdd can be mounted separately.

[0078] According to embodiments of the present invention, audible noise due to capacitor mounting can be eliminated. The process can be simplified by manufacturing the capacitor as a separate element capable of eliminating audible noise.

[0079] According to embodiments of the present invention, MEMS stress can be improved and solder detachment can be prevented by using a coverlay or PSR. Furthermore, the thickness of the substrate or cover can be reduced, thereby securing SNR performance and reducing manufacturing costs.

[0080] According to an embodiment of the present invention, the bonding reliability can be increased by bonding a shield can of the same material as the metal plate, or a lead type, non-lead type, or castle type.

[0081] According to an embodiment of the present invention, by applying half etching or full etching in various ways to a metal plate, it is possible to secure a cavity and perform flip-chip bonding, and by forming a cavity between a metal plate and a COF, it is possible to secure the wiring freedom of a 2-metal COF, and it is possible to expand the design reflection freedom such as minimizing line loss and parasitic impedance, and thereby improve SNR performance by minimizing noise level.

[0082] FIG. 1 illustrates a MEMS microphone according to one embodiment of the present invention.

[0083] FIGS. 2 to 13 are drawings for explaining a MEMS microphone according to the first embodiment of the present invention.

[0084] Fig. 14 illustrates a MEMS microphone according to a second embodiment of the present invention.

[0085] Figures 15 to 24 are drawings for explaining a MEMS microphone according to a second embodiment of the present invention.

[0086] Fig. 25 illustrates a MEMS microphone according to a third embodiment of the present invention.

[0087] Fig. 26 is a drawing for explaining a MEMS microphone according to a third embodiment of the present invention.

[0088] Fig. 27 illustrates a MEMS microphone according to a fourth embodiment of the present invention.

[0089] Figures 28 to 37 are drawings for explaining a MEMS microphone according to a fourth embodiment of the present invention.

[0090] Fig. 38 illustrates a MEMS microphone according to a fifth embodiment of the present invention.

[0091] Figures 39 to 46 are drawings for explaining a MEMS microphone according to the fifth embodiment of the present invention.

[0092] Fig. 47 illustrates a MEMS microphone according to a sixth embodiment of the present invention.

[0093] Figures 48 to 52 are drawings for explaining a MEMS microphone according to the sixth embodiment of the present invention.

[0094] FIG. 53 and FIG. 54 are drawings for explaining a MEMS microphone according to an embodiment other than that of FIG. 38 to FIG. 41.

[0095] FIGS. 55 to 59 are drawings for explaining a MEMS microphone according to an embodiment other than FIGS. 1 and 52.

[0096] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0097] However, the technical idea of ​​the present invention is not limited to some of the embodiments described, but can be implemented in various different forms, and within the scope of the technical idea of ​​the present invention, one or more of the components between the embodiments can be selectively combined or substituted for use.

[0098] In addition, terms (including technical and scientific terms) used in the embodiments of the present invention may be interpreted as having a meaning that can be generally understood by a person of ordinary skill in the technical field to which the present invention belongs, unless explicitly and specifically defined and described, and terms that are commonly used, such as terms defined in a dictionary, may be interpreted in consideration of the contextual meaning of the relevant technology.

[0099] Additionally, the terms used in the embodiments of the present invention are intended to describe the embodiments and are not intended to limit the present invention.

[0100] In this specification, the singular may also include the plural unless specifically stated otherwise in the phrase, and when it is described as “A and / or at least one (or more) of B, C”, it may include one or more of all combinations that can be combined with A, B, C.

[0101] Additionally, in describing components of embodiments of the present invention, terms such as first, second, A, B, (A), (B), etc. may be used. These terms are only intended to distinguish the components from other components, and are not intended to limit the nature, order, or sequence of the components.

[0102] And, when a component is described as being 'connected', 'coupled', or 'connected' to another component, it may include not only cases where the component is 'connected', 'coupled', or 'connected' directly to the other component, but also cases where the component is 'connected', 'coupled', or 'connected' by another component between the component and the other component.

[0103] Additionally, when described as being formed or arranged "above" or "below" each component, "above" or "below" includes not only cases where the two components are in direct contact with each other, but also cases where one or more other components are formed or arranged between the two components. Furthermore, when expressed as "above" or "below," the meaning may include not only the upward direction but also the downward direction based on one component.

[0104] Variations according to the present embodiment may include some components of each embodiment and some components of other embodiments. That is, a variation may include one embodiment among various embodiments, but may omit some components and include some components of the corresponding other embodiment. Or, the opposite may be true. The features, structures, effects, etc. described in the embodiments are included in at least one embodiment and are not necessarily limited to just one embodiment. Furthermore, the features, structures, effects, etc. exemplified in each embodiment may be combined or modified in other embodiments by a person having ordinary skill in the art to which the embodiments pertain. Therefore, the contents related to such combinations and modifications should be construed as being included within the scope of the embodiments.

[0105] FIG. 1 illustrates a MEMS microphone according to one embodiment of the present invention, and FIGS. 2 to 13 are drawings for explaining a MEMS microphone according to a first embodiment of the present invention.

[0106] A MEMS microphone (100) according to an embodiment of the present invention is composed of a first substrate (110), a second substrate (120), and a MEMS structure (130), and may include a signal processing element (140) and a housing (170).

[0107] The first substrate (110) is placed at the bottom of the MEMS microphone and has a plate shape. The first substrate (110) is a flexible substrate and may be a COF (CHIP ON FILM) substrate or a flexible printed circuit board (FPCB). A COF (CHIP ON FILM) substrate is a substrate formed by forming a circuit or mounting components such as chips on a base film, and has a film shape, so it is a substrate that is considerably thinner than other substrates. By using a COF substrate as the substrate of the MEMS microphone, the thickness can be considerably reduced. The first substrate (110) may be a 2METAL COF substrate as a COF substrate. A 2METAL COF is a substrate formed by forming a circuit or mounting components on both sides of a base film.

[0108] Here, the thickness of the first substrate (110) (e.g., 2METAL COF substrate) may be formed to a thickness of 50 UM or more. Alternatively, it may be formed to a thickness of 20 to 100 UM or 100 UM or more. However, it is not limited to the above thickness. By including a via hole in the base film, circuits or elements formed on both sides can be connected. Here, the via hole may be a micro via hole and may be configured to a size of 25 UM or less. Compared to single-sided COF, the degree of integration can be increased, the degree of freedom in packaging is improved, and FINE PITCH is possible by arranging circuits or elements on both sides. When only a rigid substrate is used, FINE PITCH application is not easy, but when a COF substrate is used, FINE PITCH application is possible, so the size of the MEMS microphone package can be reduced by 50% or more. A flexible printed circuit board (FPCB) is a flexible circuit board that is also flexible and, since the thickness of a general PCB is thin, the thickness of the MEMS microphone can be significantly reduced by using a flexible printed circuit board. In addition, other types of flexible substrates may be included. The first substrate (110) is electrically connected to a capacitor (150) through a wire (190).

[0109] The second substrate (120) is laminated on the first substrate (110) and has a plate shape. The second substrate (120) is a rigid substrate and may be a metal plate, SUS, or a reinforcing plate. SUS is a high-strength steel that mixes chromium with iron to enhance corrosion resistance. In addition, various reinforcing plates made of metal materials may be used. In addition, other types of rigid substrates that can be combined with the housing to maintain the shield may be included. The second substrate (120) is a substrate for supplementing the rigidity of the first substrate (110) and can maintain the shape of the flexible first substrate (110).

[0110] The second substrate (120) includes one or more holes (121). The second substrate (120) is positioned on top of the first substrate (110), and the hole (121) is formed in the second substrate (120) so that the first substrate (110) can be exposed to the upper portion of the second substrate (120) through the hole (121). The first substrate (110) can be electrically connected to a capacitor (150) positioned on top of the second substrate (120) through the hole (121) formed in the second substrate (120).

[0111] A housing (170) forming an internal space may be placed on the upper portion of the second substrate (120). As shown in FIG. 2, the housing (170) is placed on the upper portion of the MEMS microphone and may have a cover shape covering the second substrate (120). The housing (170) covers the second substrate (120) to form an internal space. The housing (170) may be a can type made of a metal material, and may be formed of various materials such as plastic. The housing (170) may be combined with the second substrate (120). At this time, the housing (170) and the second substrate (120) may be joined by welding. The area where the housing (170) and the second substrate (120) are joined may be joined by micro-welding. By joining the housing (170) and the second substrate (120) by micro-welding, the process of applying and hardening can solder or epoxy is unnecessary, and the can solder line or epoxy application area is also unnecessary, so the size can be reduced by the corresponding area.

[0112] A MEMS structure (130) and a capacitor (150) are arranged on the second substrate (120), and a signal processing element (140) may be arranged as shown in FIG. 2. The MEMS structure (130) may be arranged within an internal space formed by the second substrate (120) and the housing (170). The MEMS structure (130) includes a body, a back plate, and a diaphragm. A hole (122) may be formed in the first substrate (110) and the second substrate (120) at a position facing the lower portion of the MEMS structure (130). The cross-sectional area of ​​the hole (122) may be circular, but is not limited thereto. Here, the hole (122) may be an acoustic hole. The hole may be formed in an area of ​​the housing (170) facing the upper portion of the MEMS structure (130). The hole corresponds to the hole (122) of Fig. 2, except that the hole is formed in the housing (170) area.

[0113] When a hole (122) is formed in the first substrate (110) and the second substrate (120) or the housing (170), and the diaphragm vibrates due to sound pressure from the outside coming in through the hole (122), the capacitance at the back plate can be measured to sense the sound signal. In FIGS. 1 and 2, the back plate is illustrated as being positioned above the diaphragm, but it is to be understood that the diaphragm may also be positioned above the back plate.

[0114] A signal sensed in the MEMS structure (130) is transmitted to a signal processing element (140). The MEMS structure (130) and the signal processing element (140) can be electrically connected. At this time, the MEMS structure (130) and the signal processing element (140) are connected to a wire (193) through wire bonding, and the signal sensed in the MEMS structure (130) can be transmitted to the signal processing element (140) through the wire (193).

[0115] The signal processing element (140) can process an electrical signal sensed and transmitted from the MEMS structure (130). The signal processing element (140) can amplify the signal sensed by the MEMS structure (130). Here, the signal processing element (140) may include an application-specific integrated circuit (ASIC), but is not limited thereto. The signal processing element (140) may be formed as a single module and may be formed in a chip form. The signal processing element (140) may include an ASIC and an EN-CAP that applies the ASIC.

[0116] The signal processing element (140) may be disposed on the second substrate (120). At this time, the signal processing element (140) may be disposed on the second substrate (120) spaced apart from the MEMS structure (130). The signal processing element (140) may be disposed together with the MEMS structure (130) in the internal space formed by the second substrate (120) and the housing (170), and may receive a signal from the MEMS structure (130). Since the signal is transmitted between the MEMS structure (130) and the signal processing element (140) in the internal space covered by the housing (170), noise may be reduced. The signal processing element (140) may be electrically connected to the first substrate (110). A signal processed by the signal processing element (140) may be transmitted to the first substrate (110) and may be transmitted to the outside that requires the signal through the first substrate (110).

[0117] A capacitor (150) may be placed on the second substrate (120) together with a MEMS structure (130) and a signal processing element (140). When the capacitor (150) is mounted, the signal-to-noise ratio is improved, and PSRR and PSR noise are also improved. That is, through the capacitor (150), noise-related performance such as SNR, PSRR, and PSR can be improved. The capacitor (160) is electrically connected to the signal processing element (140) and can remove noise that may occur when the signal processing element (140) processes a signal.

[0118] PCBs other than the COF, which is the first substrate (110), have large VIA, LAND, PATTERN, CLEARANCE, WIRE-BONDING PAD SIZE, and CLEARANCE values, so there is no space to create an SMT SOLDER PAD that can mount a capacitance element. On the other hand, when using a COF substrate, it is possible to mount a capacitor (150) together with a MEMS structure (130) and a signal processing element (140).

[0119] The capacitor (150) may be placed on the second substrate (120), as shown in FIGS. 3 and 4, and may be electrically connected to the signal processing element (140) through wire bonding of a wire (192). In addition, the capacitor (150) may be electrically connected to the second substrate (120) through wire bonding of a wire (191) passing through a hole (121) formed in the second substrate (120). At this time, a wire pad (112) may be formed on the surface of the first substrate (110) that comes into contact with the second substrate (120), and may be connected to a wire (192) that is connected to the capacitor (150) through the wire pad (112).

[0120] The capacitor (150) and the first substrate (110) are connected through a wire (191), and the capacitor (150) can be grounded through the wire (191). Alternatively, it can exchange signals with other components, modules, or external devices connected to the first substrate (110).

[0121] As shown in FIGS. 3 and 4, the signal processing element (140) receives a signal from the MEMS structure (130) through a wire (193), and can be connected to the first substrate (110) through a wire (194) passing through a hole (121) formed in the second substrate (120). A wire pad (111) is formed on the surface of the first substrate (110) that is in contact with the second substrate (120), and can be connected to the wire (194) of the signal processing element (140) through the wire pad (111).

[0122] The signal processing element (140) and the first substrate (110) are connected to a wire (194) through wire bonding, and a signal processed in the signal processing element (140) can be transmitted to the first substrate (110) through the wire (194). In order to protect the wire bonding of the wires (381, 182) of the signal processing element (140), an EN-CAP can be applied and dried on the upper portion of the signal processing element (140) to form a protective portion. Through this, the signal processing element (140) can be prevented from being exposed to the outside.

[0123] A signal transmitted to the first substrate (110) can be transmitted to the outside through a terminal connected to the outside. At this time, the terminal connected to the outside must be exposed to the outside, not the internal space, and can be formed on the lower surface of the first substrate (110). The signal processing element (140) is connected to the first substrate (110), and the terminal connected to the outside can be formed on the lower surface of the first substrate (110), and a signal can be transmitted through a via hole connecting the upper and lower parts of the first substrate (110). When the first substrate (110) includes a plurality of layers, a via hole can be formed to penetrate each layer.

[0124] Alternatively, the signal processing element (140) may be embedded within the first substrate (110) or the second substrate (120). In addition, the signal processing element (140) may be placed on the first substrate (110), and at this time, the second substrate (120) may not be laminated at the position where the signal processing element (140) is placed, or a hole corresponding to the shape of the signal processing element (140) may be formed.

[0125] When the signal processing element (140) is embedded within the first substrate (110) and / or the second substrate (120), at least a portion of the signal processing element (140) may overlap with at least a portion of the MEMS structure (130) in the first direction, which is the upper and lower direction of the first substrate (110).

[0126] Alternatively, when the signal processing element (140) is embedded within the first substrate (110) and / or the second substrate (120), at least a portion of the signal processing element (140) may not overlap with at least a portion of the MEMS structure (130) in the first direction, which is the upper and lower direction of the first substrate (110).

[0127] It goes without saying that other elements or modules, such as capacitors (150), may be placed in the internal space where the first substrate (110) and / or the second substrate (120) and the housing (170) are formed, in addition to the MEMS structure (130) and the signal processing element (140). Other elements or modules may also be embedded within the first substrate (110) and / or the second substrate (120). When other elements, such as capacitors (150), are embedded together with the signal processing element (140), they may be embedded in a distributed manner so that their positions do not overlap or are not concentrated. Alternatively, other elements, such as capacitors (150), may be placed on the second substrate (120), and only the signal processing element (140) may be embedded.

[0128] The capacitor (150) may be embedded within the first substrate (110) and / or the second substrate (120). In addition, the capacitor (150) may be placed on the first substrate (110), and at this time, the second substrate (120) may not be laminated at the location where the capacitor (150) is placed, or a hole corresponding to the shape of the capacitor (150) may be formed.

[0129] When the capacitor (150) is embedded within the first substrate (110) and / or the second substrate (120), at least a portion of the capacitor (150) may overlap with at least a portion of the signal processing element (140) or at least a portion of the MEMS structure (130) in a first direction, which is the upper and lower direction of the first substrate (110). The capacitor (150) includes a plurality of capacitors, and at least a portion of at least one capacitor may overlap with at least a portion of the signal processing element (140) or at least a portion of the MEMS structure (130) in a first direction, which is the upper and lower direction of the first substrate (110). By arranging the signal processing element (140) and the capacitor (150) closely together, the capacitance increases, thereby improving noise-related performance, such as SNR, PSRR, and PSR.

[0130] Alternatively, when the capacitor (150) is embedded within the first substrate (110) and / or the second substrate (120), at least a portion of the capacitor (150) may not overlap with at least a portion of the signal processing element (140) or at least a portion of the MEMS structure (130) in the first direction, which is the upper and lower direction of the first substrate (110).

[0131] Unlike the hole (122) formed in the substrate area facing the lower portion of the MEMS structure (130), the hole may be formed in the housing (170) facing the upper portion of the MEMS structure (130). When the hole (122) is formed in the substrate area, there may be restrictions on the area of ​​the substrate in which the signal processing element (140) is embedded depending on the position of the hole. However, when the hole is formed in the housing (170), the hole is not formed in the substrate area, so there may be no restrictions due to the hole when embedding the signal processing element (140) inside the substrate. Therefore, more free design is possible.

[0132] The signal processing element (140) can be bonded to the first substrate (110) by forming a flip-chip BGA using the flip-chip (FLIP CHIP) method. In addition, the signal processing element (140) can be electrically connected to the wire pads of the first substrate (110) using the BGA method. The signal processing element (140) can be placed on a third substrate (not shown), which is a separate substrate of the signal processing element (140), using the flip-chip method to form a flip-chip BGA, and the flip-chip BGA itself can be placed on the first substrate (110) using ball grid array bonding. At this time, the signal of the MEMS structure (130) can be transmitted to the first substrate (110) through a wire connected to the first substrate (110) by wire bonding, and can be transmitted to the signal processing element (140) through the first substrate (110).

[0133] When a capacitor (150) is placed on a second substrate (120) and connected to a first substrate (110) by wire bonding through a hole (121) passing through the second substrate (120), the manufacturing process can be performed as shown in FIG. 5. In order to place the capacitor on the substrate, the capacitor (150) can be directly put into the packaging process upon receipt without any processing prior to the packaging process. After performing plasma and baking, a wire bonding process for the capacitor can be performed together with the die-attach and curing work and the wire bonding process. At this time, as shown in FIG. 6, epoxy can be applied to the required area at the same time, and after the capacitor and the ASIC module, which is a signal processing element (140), are bonded, the epoxy can be hardened, and a MEMS process consisting of applying silicon, bonding and curing a MEMS structure (130), and then a wire bonding process can be performed. After the wire bonding process, the process can be performed by applying and curing EN-CAPSULATION, dispensing solder, picking up and placing components, reflow, laser work, singulation, measuring, and reel packing.

[0134] As in the comparative example of the present invention of Fig. 7, when the capacitor is mounted on the substrate by the SMT process (A) rather than wire bonding, or when it is mounted by configuring it as a separate module (B, C), an additional process may be required in addition to the packaging process. In the case of mounting the capacitor (A), since EN-CAPSULATION application is required on the capacitor after SMT is completed, the capacitor SMT process cannot be performed in the shield can SMT process, and a separate SMT process (CAPACITOR SMT) for the capacitor is required before entering the packaging process.

[0135] In addition, in cases (B, C) where an interposer is applied to a capacitor and configured as a separate module, a separate process (INTERPOSER CAPACITOR) for applying an interposer to the capacitor is required.

[0136] When mounting a capacitor with SMT as shown in Fig. 7(A) to electrically connect the capacitor and the COF substrate corresponding to the first substrate, as shown in Fig. 8, the area of ​​the hole (21) etched in the metal plate corresponding to the second substrate must be formed up to the capacitor mounting section. An acoustic hole (22) for the MEMS structure must also be formed in the metal plate. Since the area of ​​the hole (21) etched corresponding to the capacitor is large, the design becomes limited.

[0137] In contrast, in the embodiment of the present invention, since the capacitor (150) is electrically connected to the first substrate (110) through wire bonding, only the area through which the wire can pass is etched on the second substrate (120). That is, as shown in FIG. 8, the area of ​​the hole (121) of the first substrate (110) can be formed small. Since the area to be etched is reduced, the process management point after etching is also reduced, and the degree of freedom in design that can reduce the shape and size of the hole depending on the application structure is increased.

[0138] As shown in Fig. 9(A), wires can be arranged only on one side of the second substrate to form a hole (123) in a straight line on one side, and as shown in Fig. 9(B), by connecting wires from the capacitor (151) toward the signal processing element, the hole (124) can be formed only in the necessary area without extending from one end to the other end. Since the area where the capacitor can be placed on the second substrate (120) is expanded, a capacitor (152) with a larger size or capacity can be applied, and thus the degree of freedom in selecting the capacitor can be increased.

[0139] For example, in the case of SMT mounting in Fig. 8, a total of eight wire bonding pads are required, including two capacitor SMT pads and six for ASIC wire bonding, which is a signal processing element. In contrast, in the case of the embodiment of the present invention in Fig. 8 and Fig. 9(A), a total of seven pads are required, and in the cases of Figs. 9(B) and 9(C), six pads are required. In addition, in the case of 9(C), a capacitor size (MM) of 1.0 X 0.5 X 0.5 may be possible, so a capacitor of a size larger than the capacitor size of 0.6 X 0.3 X 0.3 applicable in other cases can be applied.

[0140] A second substrate (120) may be laminated on a first substrate (110), and may be bonded by thermal compression. Alternatively, the bonding may be performed using a conductive double-sided tape, etc. In addition, as shown in FIG. 10, a conductive adhesive layer (180) may be formed between the bonding surfaces of the first substrate (110) and the second substrate (120). An adhesive may be applied to the conductive adhesive layer (180), or a conductive double-sided tape may be positioned. The first substrate (110) and the second substrate (120) may be bonded in various ways to perform bonding between substrates. The conductive adhesive layer (180) may include a hole (181) that overlaps with a hole (121) of the second substrate (120).

[0141] Here, the hole (121) of the second substrate (120) may be formed at a predetermined distance or more from the outer edge of the second substrate. When a hole is formed in the second substrate (120), as shown in FIG. 11, a hole (181) must also be formed in the conductive adhesive layer (180) in the corresponding area, thereby reducing the bonding area. In addition, if the bonding area is narrow depending on the shape of the hole, the bonding force may be weak, causing problems such as the substrate being peeled off. As described above, in the case of the embodiment of the present invention, since the area of ​​the hole (121) is reduced or the degree of freedom in design is increased, the bonding force can be increased by forming the hole in consideration of the bonding area, and thereby, the reliability of attachment can be increased. When the hole (121) is formed close to the outer edge of the second substrate (120), i.e., the conductive adhesive layer (180), a problem may occur because the adhesive area in the outer region is small. Therefore, when forming the hole (121), it may be formed at a predetermined distance or more from the outer edge of the second substrate.

[0142] Here, the area of ​​the hole (181) of the conductive adhesive layer (180) may be larger than the area of ​​the hole (121) of the second substrate (120). Since the resin of the adhesive of the conductive adhesive layer (180) may flow out during lamination, the area of ​​the hole (181) of the conductive adhesive layer (180) may be formed larger than the area of ​​the hole (121) of the second substrate (120). For example, the area of ​​the hole (181) of the conductive adhesive layer (180) may be formed to be 10 UM wider on one side than the area of ​​the hole (121) of the second substrate (120). Since the degree of freedom in hole design is high, the area of ​​the hole (181) of the conductive adhesive layer (180) may be formed larger than the area of ​​the hole (121) of the second substrate (120) even though the bonding area is reduced due to the increase in the area of ​​the hole (181).

[0143] As shown in Fig. 12, when a hole (21) is formed up to a section overlapping with a capacitor, both ends of the hole (21) become close to the outer edge of the conductive adhesive layer (180). For example, as shown in Fig. 12, when the package width (D0) is 2 MM, the width (D1) of the etching area of ​​the hole (21) is formed to be 1.53 MM, and the attachment width of the first substrate (110) and the second substrate (120) by the conductive adhesive layer (180) formed at both ends is 0.23 MM at one end (D3) and only 0.24 MM at the other end (D4), so that an extremely narrow section may occur, and there is a problem that peeling may occur after singulation.

[0144] In contrast, as shown in FIG. 13, when connecting capacitors by wire bonding, the area of ​​the hole (124) can be reduced compared to the hole (21) of FIG. 12, and the degree of freedom in design can also be increased, so that both ends of the hole (124) can be formed to be spaced apart from the outer edge of the conductive adhesive layer (180) by a certain distance or more. For example, as shown in FIG. 13, the width (D1') of the etching area of ​​the hole (124) can be formed to be narrow to 1.13 MM in a package width (D0) of 2 MM, and through this, the attachment width of the first substrate (110) and the second substrate (120) by the conductive adhesive layer (180) formed at both ends can be widened to 0.55 MM at one end (D3') and 0.32 MM at the other end (D4'), thereby increasing the bonding area, and through this, the attachment reliability can be improved.

[0145] In addition, by placing the capacitor (150) on top of the second substrate (120), which is a metal plate, the second substrate (120) can serve to prevent noise resulting from microphone operation from being transmitted to the capacitor (150). This can prevent PSR (Power Supply Rejection) performance from being degraded, thereby enabling improvement of PSR.

[0146] FIG. 14 illustrates a MEMS microphone according to a second embodiment of the present invention, and FIGS. 15 to 24 are drawings for explaining a MEMS microphone according to a second embodiment of the present invention.

[0147] A MEMS microphone (200) according to a second embodiment of the present invention is composed of a first substrate (110), a second substrate (120), a MEMS structure (130) and a signal processing element (140) disposed on the second substrate (120), and one or more capacitors (150, 160). In the detailed description of the first substrate (110), the second substrate (120), the MEMS structure (130) and the signal processing element (140) disposed on the second substrate (120), any description that overlaps with the detailed description of each component of FIGS. 1 to 13 will be omitted below.

[0148] A MEMS microphone according to an embodiment of the present invention may include a plurality of capacitors. The MEMS microphone may include capacitors to remove noise, and at this time, may include a capacitor for filtering power noise and a capacitor for filtering RF noise. For example, the capacitor for removing power noise may include a capacitor with a capacity of 0.1UF to 10UF, and thereby, SNR performance may be improved. The capacitor for filtering RF noise may include one or more capacitors depending on the interference frequency, and at this time, each capacitor may include a capacitor with a capacity of 10PF to 500PF. Through this, SNR or PSRR performance may be improved. As the MEMS microphone is miniaturized, there may be insufficient space to place the capacitors, and thus, the reference circuit may not be complied with and the capacitor may not be mounted, which may result in a decrease in SNR due to power noise and a decrease in SNR and PSRR performance due to RF noise. When placing a capacitor at a location away from the MEMS microphone, performance improvement is often minimal due to power noise and RF noise, and voltage drop or signal quality degradation may occur due to LINE LOSS.

[0149] A MEMS microphone according to an embodiment of the present invention can mount a capacitor by applying a stack structure in which a capacitor having a relatively large capacity is placed on a substrate and a capacitor having a relatively small capacity is stacked with other components.

[0150] The capacitor may include a first capacitor (150) and a second capacitor (161), and the first capacitor (150) may be disposed on a first substrate (110) on which a second substrate (120) is not laminated. At this time, the first capacitor (150) is disposed spaced apart from the MEMS structure (130) and the signal processing element (140), and may be electrically connected to the signal processing element (140) to transmit and receive signals. The second capacitor (161) may be laminated under the signal processing element (140). The capacity or size of the first capacitor (150) may be larger than the capacity or size of the second capacitor (161). The first capacitor (150) may be a capacitor that performs power noise filtering, and the second capacitor (161) may be a capacitor that performs RF noise filtering.

[0151] The first electrode of the second capacitor (161) stacked on the lower portion of the first substrate (110) may be electrically connected to the first substrate, and the second electrode of the second capacitor (161) may be electrically connected to the second substrate (120). Here, the first electrode of the second capacitor (161) may be an electrode connected to a signal or power source, and the second electrode of the second capacitor (161) may be an electrode connected to ground. The first electrode (162) of the second capacitor (161) may be disposed on the lower portion of the second capacitor and may be soldered to the first substrate (110). At this time, a solder resist layer (184) may be included.

[0152] The signal processing element (140) may be connected to the MEMS structure (130) and the first substrate (110) by wires, respectively. When a second capacitor (161) is stacked under the signal processing element (140), it may be difficult to electrically connect the signal processing element (140) to the first substrate (110) at the bottom, and the signal processing element (140) may be electrically connected to the first substrate (110) through wire bonding.

[0153] The second capacitor (161) may include a conductive adhesive layer (183) electrically connecting the second capacitor (161) and the second substrate (120) and a non-conductive adhesive layer (182) laminated between the conductive adhesive layer (183) and the signal processing element (140).

[0154] The second substrate (120) may include an etching area in the area where the second capacitor (161) is placed. Hole etching may be performed on the second substrate (120) to form a hole in which the second capacitor (161) can be mounted.

[0155] The first substrate (110) may include a 2METAL COF as a COF, and the second substrate (120) may be a metal plate. The MEMS microphone substrate composed of the 2METAL COF and the metal plate allows for a fine pitch design, thereby securing a space for mounting a plurality of capacitors. At this time, the first capacitor (150), which is an MLCC capacitor, and the second capacitor (161), which is an ultra-small capacitor, a silicon capacitor, may be mounted together. Here, the MLCC (MULTILAYER CERAMIC CAPACITORS) capacitor may perform power noise filtering, and the silicon capacitor may perform RF noise filtering. The ultra-small capacitor may be a silicon capacitor, and may include a first electrode, which is an upper (TOP) electrode, and a second electrode, which is a lower (BOTTOM) electrode, and each may be connected to a different node.

[0156] A space for mounting a second capacitor (161) can be secured by applying hole etching of a second substrate (120) (e.g., a metal plate) having a thickness of 50 to 100 UM or more than 100 UM. The thickness of the second substrate (120) is not limited to the above thickness. Metal plate hole etching can be performed on the lower portion of the ASIC module, which is a signal processing element (140), and an ultra-small capacitor, which is a second capacitor (161), can be mounted in the hole etching area.

[0157] The size of the ultra-small capacitor is 0.5 X 0.5 (MM), the thickness can be 0.1 MM, or 0.5 X 0.25, and if the capacitor size is different, the metal plate hole etching area can also be changed. The hole etching area is formed with an area of ​​0.65 X 0.65 MM, and the edge of the hole etching area and the second capacitor (161) can be spaced apart by 75 UM. The second substrate (120) is GND, and a distance can be maintained from the second substrate (120) for insulation.

[0158] The second capacitor (161), which is an ultra-small capacitor, can be mounted through a packaging process of ultra-small capacitor SMT mounting -> underfill application -> conductive adhesive attachment -> non-conductive epoxy application -> ASIC DIE mounting. By attaching the conductive adhesive, the ground layer (GND LAYER) of the second capacitor (161), which is an ultra-small capacitor, and the ground (GND) of the metal plate, which is the second substrate (120), can be made current-conductive. In addition, instead of attaching the conductive adhesive, conductive epoxy application and curing can be applied.

[0159] However, if the body of the ASIC DIE is GND, the process can be carried out by changing the non-conductive epoxy to a conductive epoxy after applying UNDER-FILL without attaching a conductive adhesive.

[0160] The second capacitor (161) may be stacked and placed under the first capacitor (150) rather than under the signal processing element (140). A hole-etching area may be formed by performing metal plate hole etching on the second substrate (120) under the first capacitor (150), and the second capacitor (161) and the first capacitor (150) may be stacked and placed.

[0161] A first electrode (153) of a first capacitor (150) may be positioned on the second capacitor (161), and a second electrode (154) of the first capacitor (150) may be positioned on the second substrate (120). The first electrode of the second capacitor (161) may be electrically connected to the first electrode (153) of the first capacitor (150), and the second electrode of the second capacitor may be electrically connected to the first substrate (110). The second substrate (120) may include an etching area in an area where the second capacitor (161) is disposed.

[0162] Here, the size of the second capacitor (161) stacked under the first capacitor (150) may be smaller than the size of the first capacitor (150), and hole etching may be performed in the area where the second capacitor (161) is stacked. That is, as shown in FIGS. 17 and 18, a part of the first capacitor (150) may be placed on the second substrate (120), and another part of the first capacitor (150) may be placed on the second capacitor (161) that is placed in the hole etching area of ​​the second substrate (120).

[0163] The ultra-small capacitor, which is the second capacitor (161), can be mounted through a packaging process of ultra-small capacitor SMT mounting _ under-fill application _ solder paste or conductive epoxy application _ reflow or curing. The subsequent process can be determined depending on the material applied during the solder paste or conductive epoxy application process. That is, reflow can be performed when applying solder paste, and curing can be performed when applying conductive epoxy.

[0164] In addition, it includes a metal portion (164) that is laminated on the lower part of the first capacitor (150), and the first electrode (153) of the first capacitor (150) may be positioned on the second capacitor (161), and the second electrode (154) of the first capacitor (150) may be positioned on the metal portion (164). Here, the first electrode (153) of the first capacitor (150) may be connected to the first substrate (110) by a wire.

[0165] The second substrate (120) includes a half-etched area where the metal portion (164) and the second capacitor (161) are placed, and the thickness of the half-etched area may be thinner than the thickness of other areas.

[0166] Unlike FIG. 17, where a portion of the first capacitor (150) is directly laminated on the second substrate (120), as shown in FIGS. 19 and 20, the first electrode of the two electrodes of the first capacitor (150) may be positioned on the upper portion of the second capacitor (161), and the second electrode may be positioned on the upper portion of the metal portion (164).

[0167] In order to mount the second capacitor (161), half etching is applied to etch only a predetermined thickness out of the total thickness without applying metal plate hole etching, and in order to balance the height of the second capacitor (161) placed at the bottom of the signal electrode, which is the first electrode of the first capacitor (150), and the height of the ground electrode, which is the second electrode, a METAL PIECE, which is a metal part (164), can be placed at the bottom of the GND electrode, which is the second electrode of the first capacitor (150). At this time, in order to secure the second capacitor (161) and the metal portion (164) to the half-etched area of ​​the metal plate, which is the second substrate (120), epoxy (non-conductive) is applied _ the second capacitor (161) and the metal portion (164) are secured _ curing is performed, _ MATERIAL is applied for securement of the first capacitor, which is a capacitor for removing power noise _ the first capacitor (150) is mounted _ the packaging process of reflow or curing can be performed depending on the type of MATERIAL being applied. The MATERIAL being applied can include solder paste, conductive epoxy, conductive adhesive, etc., and reflow can be performed when applying solder paste, and curing can be performed when applying conductive epoxy or conductive adhesive.

[0168] In addition, a third capacitor (165) stacked under the first capacitor (150) may be included. That is, the third capacitor (165) rather than the metal portion (164) may be stacked under the first capacitor (150). As shown in FIGS. 21 and 22, the first electrode (153) of the first capacitor (150) may be positioned on the second capacitor (161), and the second electrode (154) of the first capacitor (150) may be positioned on the third capacitor (165). The first electrode (153) of the first capacitor (150) may be connected to the first substrate (110) by a wire, and the second electrode (154) of the first capacitor (150) may be electrically connected to the first electrode (166) of the third capacitor (165).

[0169] The second substrate (120) includes a half-etched region in which the second capacitor (161) and the third capacitor (165) are arranged, and the thickness of the half-etched region may be thinner than the thickness of other regions.

[0170] In order to balance the first capacitor (150), a third capacitor (165), which is another capacitor other than the metal portion (164), may be applied. Here, the third capacitor (165) may be an ultra-small capacitor. The first electrode (153) of the third capacitor (165) may be connected to the second electrode (154) of the first capacitor (150), i.e., connected in series. By applying the third capacitor (165), it is possible to function as a SERIES CAPACITOR that is connected in series in an equivalent circuit. Through the series connection of the first capacitor (150) and the third capacitor (165), various capacitor capacities can be configured by combining the capacities of the two. The process of mounting the third capacitor (165) corresponds to the process of mounting the second capacitor (161).

[0171] It includes three capacitors, a first capacitor (150), a second capacitor (161), and a fourth capacitor (167), and can be placed on a first substrate (110) on which a second substrate (120) is not laminated. The first capacitor (150) is placed on the first substrate (110) on which the second substrate (120) is not laminated, the second capacitor (161) is laminated under the first electrode (153) of the first capacitor (150), and the fourth capacitor (167) can be laminated under the second electrode (154) of the first capacitor (150). The first electrode of the second capacitor (161) may be electrically connected to the first electrode (153) of the first capacitor (150), the second electrode of the second capacitor (161) may be electrically connected to the first substrate (110), the first electrode of the fourth capacitor (167) may be electrically connected to the first substrate (110), and the second electrode of the fourth capacitor (167) may be electrically connected to the second electrode (154) of the first capacitor (150). The first electrode (153) of the first capacitor (150) may be connected to the first substrate (110) by a wire.

[0172] Unlike in FIGS. 17 to 22, where at least a portion of the first capacitor (150) is disposed on the second substrate (120), as in FIG. 23, the first capacitor (150), the second capacitor (161), and the fourth capacitor (167) may all be disposed on the first substrate (110) on which the second substrate (120) is not laminated. A hole-etched area where the second substrate (120) is not laminated may be formed through metal plate hole-etching on the second substrate (120), and the first capacitor (150), the second capacitor (161), and the fourth capacitor (167) may be mounted on the hole-etched area. At this time, unlike the third capacitor (165) of FIG. 21, the first electrode of the fourth capacitor (167) may be electrically connected to the first substrate (110), and the second electrode of the fourth capacitor (167) may be electrically connected to the second electrode (154) of the first capacitor (150). Through this, the third capacitor (165) is not connected in series with the first capacitor (150), but is connected in parallel. Alternatively, it is obvious that the third capacitor (165) may be connected in series.

[0173] The first electrode of the fourth capacitor (167) may be electrically connected to the AVDD pad formed on the lower surface of the first substrate (110). The second electrode of the second capacitor (161) may be electrically connected to the DVDD pad formed on the lower surface of the first substrate (110).

[0174] Here, the first capacitor (150) can perform power noise removal for DVDD, and the fourth capacitor (167) can perform power noise removal for AVDD. That is, the capacitor for power noise removal in the PATH on the DVDD side, the capacitor for RF noise removal, and the capacitor for RF noise removal in the PATH on the AVDD side can each perform different roles.

[0175] In the case of including C1 as the first capacitor (150) and C2 as the second capacitor (161), a connection relationship can be configured as in Fig. 24(A), in the case of including C1 as the first capacitor (150), C2 as the second capacitor (161), and C3 as the third capacitor (165), a connection relationship can be configured as in Fig. 24(B), and in the case of including C1 as the first capacitor (150), C2 as the second capacitor (161), and C4 as the fourth capacitor (167), a connection relationship can be configured as in Fig. 24(C). At this time, C1 performs power noise removal, C2 performs RF noise removal, and C3 can be connected in series with C1 to implement various capacitor (VARIABLE CAPACITOR) capacities. C4 performs power noise removal, and C1 can be configured for DVDD and C4 for AVDD.

[0176] FIG. 25 illustrates a MEMS microphone according to a third embodiment of the present invention, and FIG. 26 is a drawing for explaining a MEMS microphone according to a third embodiment of the present invention.

[0177] A MEMS microphone according to an embodiment of the present invention includes a first substrate (110), a second substrate (120) laminated on at least one area of ​​the first substrate (110), a MEMS structure (130) and a signal processing element (140) disposed on the second substrate (120), and a capacitor element (155). The capacitor element (155) includes a capacitor (150) and an interposer (156) laminated under the capacitor (150). The capacitor element (155) may be laminated on the first substrate (110) on which the second substrate (120) is not laminated. Among the detailed descriptions of the first substrate (110), the second substrate (120), the MEMS structure (130) and the signal processing element (140) and the capacitor (150) placed on the second substrate (120), any descriptions that overlap with the detailed descriptions of each configuration of FIGS. 1 to 24 will be omitted below.

[0178] According to an embodiment of the present invention, a MEMS microphone can be equipped with a capacitor component inside the MEMS microphone by using a COF substrate and a metal plate, but side effects may occur therefrom. When AC BIAS is applied to a MEMS microphone equipped with a capacitor element inside, due to the characteristics of MLCC capacitors that simultaneously have ferroelectric / multilayer-piezo / dielectric characteristics, a deflection occurs according to the power (AC BIAS) application. That is, when AC BIAS is applied, a micro-vibration of several PM to several NM is generated due to expansion / contraction of the equipped capacitor, and this vibration is transmitted to the substrate, so that audible noise (AUDIBLE NOISE) due to the micro-vibration of the substrate may be generated. Due to this audible noise, a deterioration in PSR (Power Supply Rejection) performance may occur.

[0179] The capacitor element (155) according to an embodiment of the present invention can eliminate audible noise by including an interposer (156) under the capacitor (150). That is, rather than mounting the capacitor directly on the substrate, the capacitor is mounted on an interposer, which is a physical structure, and then mounted on the substrate, thereby absorbing interposer vibration and preventing audible noise.

[0180] An interposer (156) can be placed between a capacitor (150) and a first substrate (110), and the interposer capacitor applied inside the MEMS microphone must be miniaturized, and the capacitor element (155) including the interposer must also be miniaturized to a size of 0.6 MM X 0.3 MM X 0.35 MM or less, which is the size of the capacitor.

[0181] The capacitor size of the capacitor element (155) mounted inside the 3MM X 2MM X 0.825 MM PKG is 0.6MM X 0.3MM X 0.35TMM, and the interposer size may be 0.9MM X 0.4MM X 0.194MM or less.

[0182] The capacitor element (155) can be configured as a single element by mounting the capacitor (150) on top of the interposer (156). The interposer (156) can include any one of an FR4 printed circuit board, a metal plate, a lead frame, a ceramic printed circuit board (CERAMIC PCB), and a metal printed circuit board (METAL PCB).

[0183] Here, the interposer (156) includes an FR4 printed circuit board, and the capacitor (150) can be surface-mounted on the printed circuit board to form a single capacitor element.

[0184] In addition, the interposer (156) may include a metal plate, and a capacitor (150) may be mounted on the metal plate to form a single capacitor element. Here, the metal plate may include a first metal plate and a second metal plate, and the first metal plate and the second metal plate may form a bridge structure that is connected to both electrodes of the capacitor, respectively.

[0185] As shown in Fig. 26, an FR4 printed circuit board for a capacitor element is manufactured, a capacitor (150) is surface-mounted (SMT), singulation is performed, the unit condition is inspected, reel or tray packing is performed, and the capacitor can be surface-mounted on the board in the MEMS microphone packaging process.

[0186] When using a metal plate, a capacitor is mounted on a metal plate array. At this time, the metal plate includes a first metal plate and a second metal plate, and the first metal plate and the second metal plate form a bridge structure that is respectively connected to the two electrodes of the capacitor, so that they can be connected to different nodes. Thereafter, singulation is performed, the unit condition is inspected, reel or tray packing is performed, and the capacitor can be surface-mounted on a substrate in a MEMS microphone packaging process.

[0187] As described above, the capacitor element (155) formed as a single component can be soldered to the first substrate (110) on which the second substrate (120) is not laminated. At this time, a metal plate hole etching can be performed on the second substrate (120) to form a hole etching area, and the capacitor element (155) can be placed in the hole etching area.

[0188] The capacitor element (155) is arranged to be spaced apart from the signal processing element (140), but can be electrically connected thereto, and the signal processing element (140) can include an ASIC module. The first substrate (110) can be a flexible substrate, the second substrate (120) can be a rigid substrate, and the first substrate (110) and the second substrate (120) can be bonded by thermal compression.

[0189] FIG. 27 illustrates a MEMS microphone according to a fourth embodiment of the present invention, and FIGS. 28 to 37 are drawings for explaining a MEMS microphone according to a fourth embodiment of the present invention.

[0190] A MEMS microphone according to an embodiment of the present invention includes a first substrate (110), a MEMS structure (130), and a signal processing element (140). In the detailed description of the first substrate (110), the MEMS structure (130), the signal processing element (140), and the capacitor (150), any description that overlaps with the detailed description of each component of FIGS. 1 to 26 will be omitted below.

[0191] A MEMS microphone according to an embodiment of the present invention may include a first substrate (110) and a second substrate (120) laminated on at least one area of ​​the first substrate (110). The first substrate (110) may be a COF and may include a 2METAL COF, and the second substrate (120) may include a metal plate.

[0192] When using FR4 rigid substrates, the fine pitch rule cannot be applied, and there are limitations in reducing substrate thickness. In contrast, by utilizing 2METAL COF, the fine pitch rule can be applied, while improving warpage and utilizing the bonding structure of the metal plate, which can act as a grounding layer.

[0193] When bonding the first substrate (110) and the second substrate (120), a conductive adhesive layer (180) can be used, as shown in FIGS. 27 and 28. The conductive adhesive layer (180) can be placed between the first substrate (110) and the second substrate (120), and the first substrate (110) and the second substrate (120) can be bonded through thermocompression bonding. First, the first substrate (110) and the conductive adhesive layer (180) can be bonded through lamination, and the second substrate (120) can be bonded through lamination on top of them. Thereafter, the substrate can be formed through a hot press process. For example, the lamination can be performed at 110˚C for 20 seconds, and the hot press process can be performed at 160˚C, 60 MIN, and 20 KGF / CM.

[0194] The first substrate (110) and the second substrate (120) can also be directly bonded without a conductive adhesive layer (180). At this time, an SMT process or a bonding process can be applied.

[0195] In the SMT process, solder is applied to the 2METAL COF TOP LAYER COPPER area of ​​the first substrate (110). The solder application area can be changed depending on the conditions such as attachment reliability and metal plate rotation. After solder application, the metal plate of the second substrate (120) is placed, and reflow can be performed to bond the first substrate (110) and the second substrate (120). The metal plate can be delivered in a REEL & TAPE type or a TRAY type. The reflow process profile can be changed depending on the specifications of the applied solder, the thermal equilibrium conditions of the COF and the METAL PLATE, etc.

[0196] In the bonding process, conductive epoxy is applied to the 2METAL COF TOP LAYER COPPER area of ​​the first substrate (110) or a conductive die attach film is attached. The area of ​​epoxy application or die attach film attachment can be changed in consideration of flowability due to VISCOSITY of the epoxy. Thereafter, the metal plate of the second substrate (120) is placed, and curing is performed to bond the first substrate (110) and the second substrate (120). The metal plate can be delivered in a REEL & TAPE type or a TRAY type. The curing process can change the CURING conditions depending on the curing temperature and time conditions of the applied epoxy, die attach film, etc.

[0197] An upper adhesive layer can be laminated on the first substrate (110) and the second substrate (120). The upper adhesive layer is laminated on the second substrate (120), and the MEMS structure (130) and the signal processing element (140) can be placed on the upper adhesive layer.

[0198] When the MEMS structure (130) is mounted on a metal plate, which is a second substrate (120), the MEMS silicon may be over-hardened due to high thermal conductivity, which may generate MEMS STRESS. When MEMS stress occurs, the initial sensitivity may decrease, making calibration impossible, and the SNR may decrease due to an increase in noise floor. This can be improved by laminating an upper adhesive layer on top of the second substrate (120).

[0199] The upper adhesive layer may include a coverlay or a photo solder resist (PSR). As in FIG. 29, a PSR (126) may be laminated on top of the second substrate (120), or as in FIG. 30, a coverlay (186) may be laminated. The coverlay is a material made by applying a semi-cured adhesive to PI (POLYIMIDE), and the thermal conductivity of PI is higher than that of nickel silver or suspense, which are materials of the metal plate. The thermal conductivity of PI is 0.12 W / (M*K), and that of the nickel silver plate is 45 and that of the suspense plate is 16.2, which are 375 times higher than that of nickel silver and 135 times higher than that of suspense.

[0200] Even if a coverlay or PSR is laminated, the thickness of the entire substrate is less than 0.21 MM based on a metal plate thickness of 100 UM, so the thickness of the entire substrate can be formed thinner than when using a conventional FR4 rigid substrate.

[0201] The MEMS stress can be reduced by directly bonding the MEMS structure (130) to the upper adhesive layer (126, 186). In addition, when applying solder when bonding the first substrate (110) and the second substrate, a hermetic shielding may not be achieved due to insufficient solder caused by solder detachment during the reflow process, which may result in a degradation of SNR performance due to a leakage path. The coverlay and PSR serve as solder resists and can prevent solder detachment.

[0202] A substrate can be formed using a photo solder resist without laminating a metal plate, which is a second substrate (120). A first photo solder resist layer (126) and a second photo solder resist layer (126) can be included on the upper and lower portions of the first substrate (110), respectively. The second substrate (120) can be formed into a single substrate by directly contacting the first photo solder resist layer (126) and the second photo solder resist layer (126).

[0203] As shown in Fig. 31, PSR can be laminated on the upper and lower portions of the first substrate (110). Since the PSR is thinner than the metal plate, the thickness of the substrate can be reduced. Not only can the thickness be reduced compared to the existing FR4 RIGID PCB, but also when a metal plate is applied, thereby ensuring SNR performance and reducing the substrate manufacturing cost.

[0204] For example, the PSR thickness of the first photo solder resist layer (126) and the second photo solder resist layer (126) can be varied from 20 UM to 55 UM, respectively. Here, the thickness can be changed in units of 5 UM, thereby controlling the thickness of the entire substrate.

[0205] Through this, internal volume (back volume) expansion is possible. It can be confirmed that the internal volume applying the metal plate of Fig. 27 is V1 of Fig. 33, and the internal volume applying the PSR (126) of Fig. 32 is V2 of Fig. 34, increasing the internal volume.

[0206] The metal plate, which is the second substrate (120), can be used to function as a housing rather than a substrate. To this end, the second substrate (120) is formed to include a base facing the first substrate (110) and a side plate extending upward from the outer edge of the base, and can include a cover (127) covering the second substrate (120). The cover (171) can be in contact with an end of the side plate of the second substrate (127). The side plate can have a certain thickness, and the cover (171) can be in contact with the upper surface, which is the end of the upper end, and be joined thereto. The second substrate (127) and the cover (171) can be solder-joined. At this time, the first substrate (110) and the cover (171) can be composed of the same material, and the first substrate (110) and the cover (171) can include COF and 2METAL COF.

[0207] In forming the shape of the second substrate (120), a metal plate including a side plate may be manufactured and bonded to the first substrate (110), or a plate-shaped meta plate may be used as the base and side plate, and may be attached using eutectic bonding or a conductive adhesive. In this case, there is the advantage of singulation. Various metal plates such as nickel silver, SUS, lead frame, and FR4 may be used.

[0208] As shown in Fig. 34, the second substrate (120) is formed in a plate shape and is joined to form an internal space by covering the upper portion with a housing (170), whereas, as shown in Fig. 35, the second substrate (127) forms an internal space by forming a base and a side plate, and a cover (171) covers the second substrate (127) to form an internal space. As shown in Fig. 36, a MEMS structure (130), a signal processing element (140), etc. can be arranged in the internal space.

[0209] By changing the shape of the metal plate, which is the second substrate, 2METAL COF can be applied not only as the first substrate but also as a cover can. When 2METAL COF is applied as a cover can, the internal volume (back volume) can be expanded by reducing the thickness compared to the existing shield can. The internal volume when the metal plate of FIG. 34 is applied in a plate shape is V1 of FIG. 37, and when the shape of the metal plate is changed and 2METAL COF, which is the first substrate, is used as a cover, the internal volume of FIG. 35 is V3 of FIG. 34, confirming that the internal volume has increased. Through this, cost reduction can be expected by utilizing 2METAL COF compared to the cost of manufacturing a METAL COVER CAN. By using 2METAL COF as a cover, the cost of the shield can is reduced, and when manufactured with the same specifications as the first substrate, it can be manufactured with one type of COF, which makes material management easy and reduces costs.

[0210] The first substrate (110) may be a flexible substrate, the second substrate (120) may be a rigid substrate, the second substrate (120) may include any one of nickel silver, SUS, ceramic, and FR4, and may include a capacitor that is placed on the second substrate (120) and spaced apart from a signal processing element (140), and the signal processing element (140) may include an ASIC module.

[0211] FIG. 38 illustrates a MEMS microphone according to a fifth embodiment of the present invention, and FIGS. 39 to 46 are drawings for explaining a MEMS microphone according to a fifth embodiment of the present invention.

[0212] A MEMS microphone according to an embodiment of the present invention includes a first substrate (110), a second substrate (120) laminated on at least one area of ​​the first substrate (110), a housing (170), a MEMS structure (130) and a signal processing element (140) disposed on the second substrate (120). In the detailed description of the first substrate (110), the second substrate (120), the MEMS structure (130) and the signal processing element (140) disposed on the second substrate (120), and the capacitor (150), any description that overlaps with the detailed description of each component of FIGS. 1 to 26 will be omitted below.

[0213] The housing of the MEMS microphone according to an embodiment of the present invention may be formed as a shield can. The shield can may be composed of nickel-plated or SUS. Hereinafter, when describing the MEMS microphone with reference to FIGS. 27 to 37, the housing will be described as a shield can (170).

[0214] When applying a shield can to a MEMS microphone and using an FR4 RIGID PCB, solder is applied to the surface copper layer, the shield can is seated, and reflow is performed. At this time, a via hole is formed in the surface copper layer, which reduces the area for applying solder to seat the shield can, and problems such as solder voids occurring, rotation or tilting of the shield can after reflow, and reliability problems due to reduced bonding adhesion after bonding may occur.

[0215] The MEMS microphone according to an embodiment of the present invention improves the above problem by bonding a shield can to a metal plate, which is a second substrate (120), thereby improving performance (SNR) and SHIELD CAN bonding reliability.

[0216] The shield can (170) is bonded onto the second substrate (120). As shown in FIG. 38, the shield can (170) can be bonded to the outer surface of the second substrate (120). Here, the shield can (170) can be composed of the same material as the second substrate. The second substrate (120) and the shield can (170) can be bonded by being composed of SUS or nickel silver. The second substrate (120) and the shield can (170) can be bonded using solder (187).

[0217] Nickel silver is a material containing 15-30% zinc and 10-20% nickel in copper. It allows for solder joints without plating in its raw state. Applying plating to the shield can (170) mounting area can improve solder joint adhesion. Nickel and aluminum plating can be used. Both electroless and electrolytic plating processes are applicable.

[0218] Although SUS contains nickel (Ni), solder joint adhesion can deteriorate without plating. Therefore, plating can be applied. Unlike nickel, electroless plating can deteriorate the adhesion of the SUS surface, so electroplating is used instead.

[0219] When the second substrate (120) and the shield can (170) that are joined to each other are made of the same material, the thermal diffusivity of the two structures is the same, which can improve the bonding reliability. For example, when the second substrate (120) is a metal plate made of nickel silver and the shield can (170) is also made of nickel silver, soldering bonding is possible without gold plating because thermal equilibrium is achieved, and the bonding reliability can be improved.

[0220] In the case where the second substrate (120) is a SUS METAL PLATE, since soldering to the raw material SUS is not performed, plating can be applied to the section where the shield can (170) is installed, and plating can also be applied to the SHIELD CAN for thermal equilibrium.

[0221] When bonding the shield can (170), the shield can (170) can be bonded to the second substrate (120) in various ways, such as a LEAD type, a NON-LEAD type, or a CASTLE type.

[0222] The lead type is a form in which the shield can leg portion is formed on the outside of the shield can, and the bonding area between the substrate and the shield can leg portion is wide, which can increase bonding reliability.

[0223] The non-lead type has no shield can leg portions and instead extends straight down from the sidewall, reducing the shield can's external size by the amount of the shield can's leg portions. This allows for a smaller package size or a larger internal area for the same package size. For example, while the width of the lead section needs to be approximately 60 UM or more, the non-lead type can reduce the board size by the width of the lead if the internal area remains the same. In this case, the bonding area between the board and the shield can is reduced.

[0224] The wall type is based on the non-lead type structure, but the bridge section is formed in the shape of a wall. Various structural grafting is possible on a substrate structure such as a metal plate.

[0225] The second substrate (120) may include a mounting portion (128) in which the shield can (170) is placed in an area where it is joined to the shield can (170). As shown in FIGS. 39 and 40, the mounting portion (128) may be formed in an area where it is joined to the shield can (170). The mounting portion (128) may be formed to be thinner than the thickness of other areas other than the mounting portion. The mounting portion (128) may be formed by etching the second substrate (120). At this time, a metal plate half-etching may be performed on the second substrate (120), and the shield can (170) may be positioned on the mounting portion (128), and then soldered using solder (187), so that the area joined to the second substrate (120) is expanded, thereby improving the bonding strength and enabling hermetic shielding. Through this, joint reliability is improved, SNR performance is improved, and tolerance is improved.

[0226] The shield can (170) can be formed in various forms, such as a lead type, a non-lead type, and a wall type. The shield can (170) is composed of a top plate (172) and a side plate (173), and in the case of the lead type, it can include a lead portion, and in the case of the wall type, it can include a protrusion (174).

[0227] It includes a base plate-shaped top plate (172) and a side plate (173) extending downward from the outer edge of the top plate (172). In the case of a non-lead type, the side plate (173) has an end formed in the form of a surface that is bonded to the second substrate (120) rather than in the form of a lead or wall.

[0228] In the case of the lead type, the shield can (170) may include a lead portion that extends outward from the end of the side plate (173). The lead portion is formed to extend outwardly and perpendicular to the downward direction from the end of the side plate (173). It may extend outward at a predetermined angle that is not perpendicular to the downward direction, or may extend in a curved shape. The lead portion may be formed to extend inwardly rather than outwardly, and may have various shapes that increase the bonding area. The mounting portion (128) of the second substrate (120) may be formed to correspond to the shape of the lead portion. As shown in Fig. 41, the mounting portion (128) may be included in an area corresponding to the lead portion, and may be bonded through solder (187).

[0229] In the case of the wall type, the shield can (170) may include a plurality of protrusions (174) extending downward from the end of the side plate (173) and spaced apart from each other. The protrusions (174) may be formed spaced apart at a predetermined interval along the side plate (173), as shown in FIG. 42.

[0230] The second substrate (120) may not be laminated in the area corresponding to the protrusion (174) of the shield can (170). The second substrate (120) may be etched in the area corresponding to the protrusion (174) of the shield can (170) so that the end of the protrusion (174) of the shield can (170) may be bonded to the first substrate (110). That is, the end of the side plate (173) where the protrusion (174) of the shield can (170) is not formed may be bonded to the second substrate (120), and the protrusion (174) of the shield can (170) may be bonded to the first substrate (110).

[0231] The area of ​​the second substrate (120) that is connected to the end of the shield can (170) can also be formed to be thinner than other areas by half-etching.

[0232] The side surface of the protrusion (174) connecting the end of the side plate (173) of the shield can (170) and the end of the protrusion (174), and the end of the side plate of the shield can (170) can be bonded to the second substrate (120). When a conductive adhesive layer (180) is included between the first substrate (110) and the second substrate (120), the side surface of the protrusion (174) can be bonded to the second substrate (120) and the conductive adhesive layer (180). That is, compared to the non-lead type in which only the end of the side plate (173) is bonded, the bonding area increases, so that the bonding strength can be improved.

[0233] By applying full or half etching of the metal plate to the second substrate (120) and forming a shield can in the form of a wall type including a protrusion (174), more solid and deep mounting is possible. The bonding area where the protrusion (174) of the shield can (170) is formed is where the mounting surface of the shield can (170) and the first substrate (110), 2METAL COF TOP COPPER, are bonded, and the section where the protrusion (174) is not formed is where the side and surface layer area of ​​the metal plate are bonded. If the second substrate (120) is a nickel-plated metal plate, a separate plating process for bonding may not be required, and if it is a silver-plated metal plate, a plating process may be applied. In the case of nickel-plated metal, plating may also be applied to increase solder joint adhesion.

[0234] The shield can (170) and the first substrate (110), and the epoxy or silicone that fills the step difference in the area where the shield can (170) and the second substrate (120) are joined can be joined together with the shield can (170). As shown in FIG. 43, a step section may exist when the shield can (170) and the second substrate (120) having a shape like a castle wall are joined, and can be joined together with a material (188) for sealing the shield can. In addition, the area where the protrusion is formed is joined together with the TOP LAYER COPPER PAD of the first substrate (110) and the material for sealing the shield can, so that the bonding area is widened, thereby increasing the bonding reliability and the airtightness of the shield can.

[0235] A material (188) for sealing the shield can may include at least one of solder paste, silver epoxy, conductive epoxy, and silicone. The solder paste performs reflow as a post-process, and if the metal plate is nickel silver, it can be applied with or without plating, and if it is suspense, plating may be required. The silver epoxy performs oven curing as a post-process, and if the metal plate is nickel silver or suspense, it can be applied without plating in both cases. The conductive epoxy and silicone perform oven curing, and if the metal plate is nickel silver or suspense, it can be applied without plating in both cases.

[0236] When the protrusion is formed in the corner area of ​​the second substrate (120), the shield can can be more firmly contacted. The upper plate (172) of the shield can (170) has a rectangular shape, and the side plate (173) of the shield can (170) includes first to fourth side plates extending from the upper plate, and a plurality of protrusions (175) can be formed to extend downward from the ends of the side plates along the shape of the corners at which two adjacent side plates among the first to fourth side plates are connected. As shown in FIGS. 44 and 46, the protrusions can include four protrusions (175) formed in the corner area, and the four protrusions (175) can be formed to span two adjacent side plates in the corner area, respectively. Epoxy or silicone (188) that fills the step gap between the shield can (170) and the first substrate (110), and the area where the shield can (170) and the second substrate (120) are joined can be joined together with the shield can (170). As shown in Fig. 45, a material (188) for sealing the shield can can be joined together.

[0237] By performing full etching of a metal plate on the second substrate (120) to correspond to the shape of the protrusion (175), a dam to dam (DAM TO DAM) bridge structure is formed, and the protrusion (175) is placed between the DAM TO DAM, thereby improving the bonding reliability and airtightness, and preventing the shield can from rotating after reflow.

[0238] Full etching is applied to the second substrate (120) so that the protruding leg portion of the shield can (170) can be positioned between the dams, and a bridge structure can be applied between the dams. The bridge structure can be applied so that the second substrate (120) is not separated into two. In the full etching area where there is no bridge structure between the dams, the copper pad of the 2METAL COF, which is the first substrate (110), can be exposed.

[0239] The metal plate, which is the second substrate (120) to which the bridge + dam TO dam structure is applied, and the 2METAL COF, which is the first substrate (110), can be bonded with a conductive adhesive layer (180), and a material (188) for sealing the shield can can be bonded together. The material (188) for sealing the shield can can include at least one of solder paste, silver epoxy, conductive epoxy, and silicone.

[0240] After applying a material (188) for sealing the shield can and mounting (PICK & PLACE) the shield can so that the protrusion (175) of the shield can is inserted between the dams, a reflow or oven cure (REFLOW (SOLDER), OVEN CURE (EPOXY, SILICON, AG EPOXY, etc.) process can be performed depending on the joining material.

[0241] Fig. 47 illustrates a MEMS microphone according to the sixth embodiment of the present invention, and Figs. 48 to 52 are drawings for explaining a MEMS microphone according to the sixth embodiment of the present invention.

[0242] A MEMS microphone according to an embodiment of the present invention includes a first substrate (110), a second substrate (120) laminated on at least one area of ​​the first substrate (110), a housing (170), a MEMS structure (130) and a signal processing element (140) disposed on the second substrate (120). In the detailed description of the first substrate (110), the second substrate (120), the MEMS structure (130) and the signal processing element (140) disposed on the second substrate (120), any description that overlaps with the detailed description of each component of FIGS. 1 to 46 will be omitted below.

[0243] In the case of FR4 rigid board, the cost increase is inevitable for applying a cavity board. In addition, the area where the cavity can be applied is limited due to the design rule space such as line space, clearance, and via. In the case of flip-chip bonding, it must be applied to the surface of the FR4 rigid substrate top layer, which increases the thickness and inevitably reduces the internal volume. Although the thickness can be reduced through embedded MEMS and ASIC, the RDL (RE design layer) process of MEMS and ASIC is required, and the high-spec process for burring inside the PCB is required, so the cost increase is inevitable.

[0244] The MEMS microphone according to an embodiment of the present invention can implement various cavity structures through etching of the second substrate (120).

[0245] The second substrate (120) includes an etching area in which a MEMS structure (130) or a signal processing element (140) is arranged, and the thickness of the etching area is formed thinner than the thickness of other areas other than the etching area. The second substrate (120) may include a capacitor (150) that is arranged in the etching area of ​​the second substrate (120) and spaced apart from the signal processing element (140) in the internal space of the housing (170). The signal processing element (140) may include an ASIC module.

[0246] A cavity can be secured by applying half-etching, which etches a portion of the second substrate (120) in an area where a MEMS structure (130), a signal processing element (140), or a capacitor (150) is arranged. As shown in Fig. 47, the thickness of the half-etched area can be formed to be thinner than the thickness of other areas, W1, with W2, thereby forming a cavity. The thickness at which half-etching is performed can vary depending on the thickness of the metal plate, which is the second substrate (120).

[0247] For example, when applying half-etching to a metal plate with a thickness of 0.1 mm, the etching can be done to a thickness of 0.05 mm. If the metal plate is 0.2 mm thick, the etching can be arranged to a thickness of 0.1 mm when applying half-etching. Naturally, etching can be done to a thickness greater than half the thickness. This allows for improved internal volume within the same package size.

[0248] When bonding the MEMS structure (130) to the second substrate (120), epoxy or silicon may be applied within the etched area. The half-etched area may serve as a guideline for applying silicon (for MEMS die mounting) or epoxy (for SILICON die mounting), and may suppress the flow of silicon or epoxy before curing. Silicon may be applied to the etched area corresponding to the MEMS structure (130), and epoxy may be applied to the etched area corresponding to the signal processing element (140) or capacitor (150). The unetched area of ​​the second substrate (120) between the two areas may also serve as a dam (DAM) to prevent mixing of silicon and epoxy.

[0249] The second substrate (120) may not be laminated in the area where the MEMS structure (130) or the signal processing element (140) is arranged. A cavity can be secured by using hole etching that forms a hole as well as half etching. The second substrate (120) can be removed by hole etching the second substrate (120) in the area where the MEMS structure (130) or the signal processing element (140) is arranged. Hole etching forms a hole by removing the entire second substrate, and can be referred to as full etching.

[0250] Etching may be applied only to a portion of the area where the MEMS structure (130), signal processing element (140), and capacitor (150) are placed.

[0251] As shown in Fig. 48, full etching may be applied to the MEMS structure (130) region, and no etching may be applied to the signal processing element (140) or capacitor (150) region. As shown in Fig. 49, full etching may be applied to the MEMS structure (130) region, and half etching may be applied to the signal processing element (140) or capacitor (150) region. As shown in Fig. 50, full etching may be applied to all of the MEMS structure (130), signal processing element (140), and capacitor (150) regions.

[0252] A cavity can be secured by applying full etching and half etching in various ways. Through this, internal volume improvement is possible based on the same package size, and the full etching and half etching areas can serve as guidelines for applying silicon (for MEMS die mounting) and epoxy (for SILICON die mounting), and the flow of silicon or epoxy can be suppressed before curing. Silicon can be applied to the etching area corresponding to the MEMS structure (130), and epoxy can be applied to the etching area corresponding to the signal processing element (140) or capacitor (150). The unetched second substrate (120) area between the two areas can also serve as a dam (DAM) to prevent mixing of silicon and epoxy.

[0253] The etching area of ​​the second substrate (120) can form a cavity by etching the surface facing the first substrate (110). As shown in Fig. 51, when etching is applied to the second substrate (120), etching can be applied to the lower portion of the second substrate (120), i.e., the surface facing the first substrate (110), rather than the upper portion of the second substrate (120). An internal cavity space covered by the second substrate (120) can be formed. A wiring electrically connected to the first substrate (110) can be arranged in the cavity.

[0254] By applying half-etching to the lower surface, i.e., the 2METAL COF side of the first substrate (110), rather than the upper surface of the second substrate (120) on which the MEMS structure (130) and signal processing element (140) are arranged, it is possible to secure the wiring freedom of the 2METAL COF. As the wiring freedom of the 2METAL COF is secured, the design freedom can be expanded, such as minimizing LINE LOSS and parasitic IMPEDANCE, and from this, SNR performance can be improved by minimizing NOISE LEVEL.

[0255] In addition, it is possible to secure 2METAL COF wiring freedom while maintaining the existing package structure, and the ASIC and MLCC CAPACITOR layout can be changed and expanded in a narrow space according to the secured wiring freedom.

[0256] Flip-chip bonding of the MEMS structure (130) or signal processing element (140) can be applied simultaneously with full etching or half etching applied to the second substrate (120). As shown in Fig. 52, flip-chip bonding is possible by directly bonding the MEMS structure (130) or signal processing element (140) to the first substrate (110) using solder (189), and the MEMS structure (130) can be changed upside down for flip-chip bonding.

[0257] This allows for internal volume expansion, which can improve SNR. By performing flip-chip bonding, the wire bonding line is eliminated, and the ASIC and the 2METAL COF SIGNAL LINE are directly connected, reducing signal loss and improving impedance. In addition, the wire bonding process can be eliminated. In the case of FR4 RIGID PCB, embedded MEMS and ASIC are required to achieve the same effect, which inevitably increases the substrate cost. However, by simply expanding the etching area, the embedded MEMS and ASIC effect can be applied, reducing the substrate cost.

[0258] As shown in Fig. 38, in order to bond a housing (170) on a second substrate (120), or to form a mounting portion (128) as shown in Fig. 39, half-etching may be performed on the second substrate (120), and instead of bonding the housing (170), a cover can, which is a housing (170), may be mounted on a first substrate (110) instead of the second substrate (120) as shown in Figs. 53 and 54. At this time, the housing (170) may be SMT-mounted to the electrode pad (COPPER PAD) of the 2METAL COF, which is the first substrate (110). Since the housing (170) is located on the outer side of the second substrate (120), its position may be guided and fixed. After the housing (170) is mounted, it may be bonded using solder (201).

[0259] Compared to the case where the housing (170) is joined through half-etching to the second substrate (120), the overlapping length of the housing (170) and the second substrate (120) can be increased. For example, in the case of half-etching, it is 50 UM, whereas in the case according to the embodiments of FIGS. 53 and 54, it can be increased to 100 UM. Through this, the bonding area of ​​the solder (201) is increased, thereby improving the airtight shielding, and thus improving the SNR sensitivity change or performance degradation due to AIR LEAKAGE.

[0260] As shown in Fig. 56, flip-chip bonding can be applied to directly bond the signal processing element (140) to the first substrate (110). At this time, flip-chip bonding can be applied to the signal processing element (140). Flip-chip bonding can be applied to the signal processing element (140) while applying full etching or half etching to the metal plate, which is the second substrate (120). Volume expansion is possible through etching the metal plate, and SNR can be improved thereby.

[0261] When applying flip-chip bonding to the signal processing element (140), as shown in FIG. 55, the wire bonding wire (203) for connecting the signal processing element (140) and the first substrate (110) with a wire can be deleted, and the wire bonding pad area (202) of the first substrate (110) for wire bonding can also be deleted. By directly contacting the signal processing element (140) and the first substrate (110) through flip-chip bonding, signal loss can be reduced and impedance can be improved.

[0262] Additionally, the wire bonding pad area (202) is deleted, which allows the substrate size to be reduced, thereby reducing the size of the entire package.

[0263] In the case of FR4 RIGID PCB, an embedded signal processing element (ASIC) is required to achieve the same effect, which inevitably increases the substrate cost. However, by applying the embedded ASIC effect through etching of the second substrate (120) and flip-chip bonding of the signal processing element (140), the substrate cost can be drastically reduced.

[0264] The upper part of Fig. 57 illustrates a wire connection or circuit connection according to the embodiment of Fig. 55, and the lower part illustrates a wire connection or circuit connection according to the embodiment of Fig. 56. As in 211, the number of wire bonds can be reduced from 11 to 3. In the embodiment of Fig. 55, a total of 11 wires (205) connecting the MEMS structure (130) and the signal processing element (140), a wire (204) connecting the capacitor (150) and the signal processing element (140), and a wire (203) connecting the signal processing element (140) and the substrate (110) are required, but in the case of the embodiment of Fig. 56, only 3 wires (205) connecting the MEMS structure (130) and the signal processing element (140) are required by directly contacting the capacitor (150) and the signal processing element (140) to the first substrate (110) without wire bonding, thereby reducing the number of wire bonds. Here, the first substrate (110) may include a thin film FINE-PITCH FLEXIBLE substrate. The wires to be deleted may be connected through a circuit, such as 212 (the second substrate (120) and the first substrate (110)) and 213 (the LAYER TOP circuit of the first substrate (110)). In addition, through wire bonding deletion, the wire bonding pads of the first substrate (110) may be deleted, thereby reducing the size of the MEMS microphone substrate and the overall package.

[0265] In addition, since the degree of freedom of wiring is secured by applying direct bonding, the LAYER BOT circuit of the first substrate (110) can be simplified, as in 214 (LAYER BOT circuit of the first substrate (110)), and there is a process advantage in that there is no need to apply solder resist, etc. to the LAYER BOT.

[0266] As the wire bonding pad section is removed, a free space (220) is secured in the lower substrate area, which allows the substrate length to be reduced and the package size to be reduced. For example, the lower PCB length can be reduced by 0.13 mm, and the package size can be reduced from 3X2MM to 2.87X2MM.

[0267] In addition, as shown in FIGS. 58 and 59, the wire bonding direction of the MEMS structure (130) can be applied to the side rather than the direction of the signal processing element (140), thereby reducing the wire bonding length. The reduced wire bonding length can be implemented as a circuit within the substrate, as shown in the circuit of FIG. 59, thereby reducing the cost. In this case as well, as the wire bonding pad section is deleted, a free space (220) in the lower substrate area is secured, thereby reducing the substrate length and the package size. For example, the lower PCB length can be reduced by 0.13 MM, and the package size can be reduced from 3X2 MM to 2.87X2 MM.

[0268]

[0269] Those skilled in the art will appreciate that the present invention can be implemented in modified forms without departing from the essential characteristics of the above-described description. Therefore, the disclosed methods should be considered illustrative rather than restrictive. The scope of the present invention is set forth in the claims, not the foregoing description, and all differences within the scope equivalent thereto should be construed as being encompassed by the present invention.

Claims

1. First substrate; A second substrate laminated on the first substrate; A MEMS structure disposed on the second substrate; and A capacitor is disposed on the second substrate and spaced apart from the MEMS structure, The second substrate includes one or more holes, A MEMS microphone in which the capacitor is electrically connected to the first substrate through a wire passing through a hole in the second substrate.

2. In paragraph 1, The hole of the above second substrate is, A first hole through which a wire connecting the capacitor and the first substrate passes; and A MEMS microphone including a second hole corresponding to the lower portion of the above MEMS structure 3. In paragraph 1, A MEMS microphone in which the hole of the second substrate is formed at a predetermined distance from the outer surface of the second substrate.

4. In paragraph 1, A conductive adhesive layer is included between the first substrate and the second substrate, A MEMS microphone, wherein the conductive adhesive layer includes a hole overlapping the hole of the second substrate.

5. In paragraph 4, A MEMS microphone in which the area of ​​the hole of the conductive adhesive layer is larger than the area of ​​the hole of the second substrate.

6. In paragraph 1, A MEMS microphone in which the first substrate includes a connection pad positioned at a position corresponding to the lower portion of the hole of the second substrate.

7. In paragraph 1, An ASIC module is disposed on the second substrate and spaced apart from the MEMS structure, The above ASIC module is a MEMS microphone electrically connected to the first substrate through a wire passing through a hole in the second substrate.

8. In paragraph 7, The above ASIC module is a MEMS microphone electrically connected to the above MEMS structure and the above capacitor via wires, respectively.

9. In paragraph 1, A MEMS microphone wherein the first substrate is a flexible substrate and the second substrate is a rigid substrate.

10. In paragraph 1, A MEMS microphone in which the first substrate and the second substrate are joined by thermal compression.

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