MEMS microphone

Abstract

The MEMS microphone according to an embodiment of the present invention comprises: a first substrate; a second substrate stacked on the first substrate and having a cavity formed therein; an interposer disposed inside the cavity and coupled to the first substrate; a housing coupled to the first substrate to form an accommodation space therein; a MEMS structure disposed on top of the second substrate in the accommodation space; and a signal processing element spaced apart from the MEMS structure and disposed on top of the second substrate in the accommodation space, wherein at least one of the MEMS structure and the signal processing element may be coupled to the interposer.

Description

MEMS microphone

[0001] The present invention relates to a MEMS microphone, and more specifically, to a MEMS microphone utilizing an interposer.

[0002]

[0003] Generally, audio devices generate sound by vibrating a diaphragm using electrodes, and significant advancements are being made in the field of audio equipment alongside recent technological developments. The applications of these devices are becoming increasingly diverse, such as in portable terminals and hearing aids; furthermore, as the devices in which they are applied become slimmer, the size of the audio devices themselves is also becoming smaller.

[0004] In addition, microphones utilizing MEMS (Micro Electro Mechanical Systems), a semiconductor technology, have recently been developed and are in use. MEMS is a technology that enables the manufacturing of small mechanical components. These MEMS microphones can be classified into electrostatic and piezoelectric types, and include the general capacitor type.

[0005] Recently, mobile communication terminals such as mobile phones and smartphones, as well as electronic devices like tablet PCs and MP3 players, are becoming smaller. Consequently, the components of these electronic devices are also becoming more miniaturized. Therefore, Micro Electro Mechanical System (MEMS) technology is required to overcome the physical limitations of these components.

[0006]

[0007] The technical problem that the present invention aims to solve is to provide a MEMS microphone that can secure packaging reliability by mounting a MEMS structure and a signal processing element on an interposer.

[0008]

[0009] To solve the above technical problem, a MEMS microphone according to an embodiment of the present invention comprises: a first substrate; a second substrate laminated on the first substrate and having a cavity formed therein; an interposer disposed inside the cavity and coupled with the first substrate; a housing coupled to the second substrate and forming a receiving space inside; a MEMS structure disposed on the upper portion of the second substrate in the receiving space; and a signal processing element spaced apart from the MEMS structure and on the upper portion of the second substrate in the receiving space; wherein one or more of the MEMS structure and the signal processing element may be coupled on the interposer.

[0010] Additionally, the second substrate comprises a first region where the housing is disposed, a second region where the MEMS structure is disposed, and a third region where the signal processing element is disposed, and the cavity may be disposed in one or more of the second region and the third region.

[0011] In addition, the cavity may be placed in the second region, and the MEMS structure may be coupled to the interposer.

[0012] In addition, the cavity is disposed in the third region, and the signal processing element can be coupled on the interposer.

[0013] In addition, the cavity may be positioned through the second region and the third region, and the MEMS structure and the signal processing element may be positioned on the interposer.

[0014] Additionally, the interposer comprises a first interposer disposed in the second region of the cavity; and a second interposer disposed spaced apart from the first interposer and disposed in the first region of the cavity, wherein the MEMS structure may be disposed on the first interposer and the MEMS structure may be disposed on the second interposer.

[0015] Additionally, the first interposer may include a first embedded capacitor, and the second interposer may include a second embedded capacitor.

[0016] In addition, the first substrate may include a 2Metal COF substrate.

[0017] Additionally, the first substrate may include a plurality of first pads on an upper surface, and the interposer may include a second pad disposed on an upper surface for electrically connecting one or more of the MEMS structure and the signal processing element, and a third pad disposed on a lower surface that contacts the first pad.

[0018] Additionally, the interposer comprises a plurality of insulating layers, one or more vias and pads disposed between the insulating layers, and one or more of the insulating layers may include an embedded capacitor.

[0019]

[0020] The MEMS microphone according to an embodiment of the present invention has the following effects.

[0021] First, the area where the bonding sheet is placed between the first substrate and the second substrate can be expanded compared to the conventional method, which not only resolves the problem of delamination between the first and second substrates but also has the effect of increasing bonding reliability.

[0022] In addition, by combining the signal processing element and the capacitor in a flip-chip form with the interposer, the signal processing element and the capacitor are electrically connected to the first substrate through the interposer. This not only reduces damage to the signal processing element or the capacitor but also reduces the length of the wire used for wire bonding, thereby reducing wire costs and resulting in an overall reduction in manufacturing costs.

[0023] In addition, since the design of the first pad, first connection circuit, and first via of the first substrate can be simplified or omitted, the manufacturing process of the first substrate is simplified, and the thickness of the substrate unit can be reduced compared to the conventional method. As the internal back chamber volume increases, the signal-to-noise ratio (SNR) is improved, and the dynamic range is increased.

[0024] In addition, by placing an embedded capacitor inside the interposer, the capacitor effect can be enjoyed without having to separately mount or place a capacitor to reduce noise generated by the power supply, and if necessary, since the embedded capacitor is also divided when the interposer is divided, it is possible to place two or more capacitors through the interposer.

[0025] In addition, depending on how the interposer is positioned during the product design process, the back chamber volume of the MEMS microphone accommodation space can be increased or the front chamber volume can be increased, allowing for the manufacture of a desired MEMS microphone depending on the number of internal capacitors or circuit design, which has the effect of increasing the design freedom of the product.

[0026]

[0027] FIG. 1 is a side view illustrating the structure of a MEMS microphone according to a first embodiment of the present invention.

[0028] FIG. 2 is a top view illustrating the structure of a MEMS microphone according to a first embodiment of the present invention.

[0029] FIG. 3 is a diagram illustrating the substrate unit structure of a MEMS microphone according to a first embodiment of the present invention.

[0030] FIG. 4 is a side view illustrating the structure of a MEMS microphone according to a second embodiment of the present invention.

[0031] FIG. 5 is a top view illustrating the structure of a MEMS microphone according to a second embodiment of the present invention.

[0032] FIG. 6 is a diagram illustrating the substrate unit structure of a MEMS microphone according to a second embodiment of the present invention.

[0033] FIG. 7 is a side view illustrating the structure of a MEMS microphone according to a third embodiment of the present invention.

[0034] FIG. 8 is a top view illustrating the structure of a MEMS microphone according to a third embodiment of the present invention.

[0035] FIG. 9 is a side view illustrating the structure of a MEMS microphone according to a fourth embodiment of the present invention.

[0036] FIG. 10 is a side view illustrating the structure of a MEMS microphone according to a fifth embodiment of the present invention.

[0037]

[0038] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0039] However, the technical concept of the present invention is not limited to some of the described embodiments but can be implemented in various different forms, and within the scope of the technical concept of the present invention, one or more of the components among the embodiments may be selectively combined or substituted.

[0040] In addition, terms used in the embodiments of the present invention (including technical and scientific terms) may be interpreted in a sense that is generally understood by those skilled in the art to which the present invention belongs, unless explicitly and specifically defined otherwise. Terms that are commonly used, such as terms defined in advance, may be interpreted in consideration of their meaning in the context of the relevant technology.

[0041] Furthermore, the terms used in the embodiments of the present invention are for the purpose of describing the embodiments and are not intended to limit the present invention.

[0042] In this specification, the singular form may include the plural form unless specifically stated otherwise in the text, and when described as "at least one of A and B and C (or more than one)," it may include one or more of all combinations that can be formed from A, B, and C.

[0043] In addition, terms such as first, second, A, B, (a), (b), etc., may be used when describing the components of the embodiments of the present invention. These terms are used merely to distinguish the components from other components and are not intended to limit the essence, order, or sequence of the components.

[0044] And, where it is stated that a component is 'connected', 'combined', or 'connected' to another component, this may include not only cases where the component is directly 'connected', 'combined', or 'connected' to the other component, but also cases where it is 'connected', 'combined', or 'connected' due to another component located between the component and the other component.

[0045] Furthermore, when described as being formed or placed "above" or "below" each component, "above" or "below" includes not only cases where two components are in direct contact with each other, but also cases where one or more other components are formed or placed between the two components. Additionally, when expressed as "above" or "below," it may include the meaning of a downward direction as well as an upward direction relative to a single component.

[0046] 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 of the various embodiments, but with some components omitted and some components of a corresponding other embodiment included. Or, the opposite may be true. Features, structures, effects, etc. described in the embodiments are included in at least one embodiment and are not necessarily limited to only one embodiment. Furthermore, features, structures, effects, etc. exemplified in each embodiment may be combined or modified and implemented in other embodiments by a person with ordinary knowledge in the field to which the embodiments belong. Therefore, details regarding such combinations and modifications should be interpreted as being included within the scope of the embodiments.

[0047] FIG. 1 is a side view illustrating the structure of a MEMS microphone according to a first embodiment of the present invention, FIG. 2 is a top view illustrating the structure of a MEMS microphone according to a first embodiment of the present invention, and FIG. 3 is a drawing illustrating the substrate unit structure of a MEMS microphone according to a first embodiment of the present invention.

[0048]

[0049] Referring to FIGS. 1 to 3, a MEMS microphone according to a first embodiment of the present invention may include a first substrate (100), a second substrate (200), a MEMS structure (300), a housing (400), a signal processing element (500), a capacitor (600), a bonding sheet (700), and an interposer (800).

[0050] The first substrate (100) is a substrate that is placed at the bottom of a MEMS microphone and can form a circuit in the shape of a plate. The first substrate (100) is a flexible substrate and may be a Chip on Film (COF) substrate or a flexible printed circuit board (FPCB). For example, the first substrate (100) may be a Liquid Crystal Polymer (LCP) based FPCB, a Polyimide (PI) based FPCB, or a PI based COF, and the type of the first substrate (100) is not limited to the examples described above.

[0051] A COF (Chip on Film) substrate is a substrate formed by forming a circuit or mounting components such as chips on a base film. Because it has a film shape, it is a substrate that is thinner than other substrates. By using a COF substrate as the substrate for a MEMS microphone, the thickness can be reduced compared to using a conventional rigid substrate.

[0052] The first substrate (100) is a COF substrate and may include a 2-metal COF substrate. The 2-metal COF may be formed in a structure in which metal layers are laminated on the upper and lower surfaces of a base film so as to form circuits or mount devices on both sides of a base film.

[0053] The first substrate (100) may include via holes. In this case, the first substrate (100) can connect circuits or components formed on both sides through a metal layer (e.g., via) formed in the via holes. Here, the via holes may be micro via holes and may be configured with a size of 25 μm or less. Compared to a single-sided COF, the integration density can be increased, the degree of freedom during packaging is improved, and fine pitch is possible by placing circuits or components on both sides. When only a rigid substrate is used, it is difficult to apply fine pitch because the base thickness is thick during design, but when a COF substrate is used, it is significantly thinner than the substrate, making fine pitch application possible, and thus the size of the MEMS microphone package can be reduced by more than 50%.

[0054] A flexible printed circuit board (FPCB) is a flexible circuit board that is also flexible and thinner than a standard PCB board, so the thickness can be reduced by using a flexible printed circuit board as the substrate for a MEMS microphone. In addition, other types of flexible substrates may be included.

[0055] The first substrate (100) may include an acoustic hole (10). The cross-sectional area of ​​the acoustic hole (10) may be circular, but is not limited thereto. A MEMS structure (300) may be disposed on the upper portion of the acoustic hole (10) formed in the first substrate (100).

[0056] The first substrate (100) can be electrically connected to a signal processing element (500) and a capacitor (600). A metal layer may be formed on the first substrate (100) to be electrically connected to the signal processing element (500) and the capacitor (600). Here, the metal layer may include a plurality of pads and a plurality of vias. The pads may overlap and contact the vias perpendicularly, or may contact an external substrate or element. The vias may be formed in via holes penetrating a base film or an insulating layer. The arrangement of the plurality of pads, the plurality of connection circuits, and the plurality of vias may be changed according to the circuit design structure. Here, the pad formed on the first substrate (100) is defined as the first pad (110), and the via formed on the first substrate (100) is defined as the first via (120).

[0057] The second substrate (200) is laminated to be placed on top of the first substrate (100) and has a plate shape. The second substrate (200) may be a rigid substrate to complement the rigidity of the first substrate (100), and may include, for example, one or more of a metal plate, a stainless steel (SUS), and a reinforcing plate. Stainless steel (SUS) is a type of steel in which chromium is mixed with iron to enhance corrosion resistance, and refers to a high-strength substrate. In addition to the above configuration, various reinforcing plates made of metal material may be used for the second substrate (200). Because the second substrate (200) complements the rigidity of the first substrate (100), the flexible first substrate (100) can maintain its shape.

[0058] The second substrate (200) may include an acoustic hole. The cross-sectional area of ​​the acoustic hole may be circular, but is not limited thereto, and may have a size corresponding to the acoustic hole formed in the first substrate (100), but there is no limitation on the size. The acoustic hole formed in the second substrate (200) may communicate with the acoustic hole formed in the first substrate (100) to form a single acoustic hole (10), and a MEMS structure (300) may be disposed on the upper part of the acoustic hole (10).

[0059] The second substrate (200) may include one or more cavities (210). The second substrate (200) is placed on top of the first substrate (100), and the first substrate (100) may be exposed through the cavity (210) of the second substrate (200). One or more of a plurality of pads, a plurality of connection circuits, and a plurality of vias may be placed in the first substrate (100) in an area that overlaps vertically with the cavity (210) of the second substrate (200).

[0060] The second substrate (200) can be divided into a first area (200a) for housing placement based on the upper surface, a second area (200b) for MEMS structure (300) placement, and a third area (200c) for signal processing element (500) and capacitor (600) placement.

[0061] The first region (200a) is an area where the lower surface of the housing can be joined, and can be defined as the border area of ​​the second substrate (200). The second region (200b) and the third region (200c) may be disposed within the inner area of ​​the first region (200a). The housing (400) may be connected to the first region (200a) by the second substrate (200) undergoing a half-etching process, the lower surface of the housing (400) may be connected to the upper part of the first region (200a), and a bonding sheet (700) may be disposed at the lower part of the first region (200a). In this case, the border width of the first region (200a) may be designed to have a width that satisfies the adhesion reliability between the first substrate (100) and the second substrate (200) by the bonding sheet (700).

[0062] The second region (200b) is a region for placing a MEMS structure (300) and can be placed on one side inside the first region (200a) based on the upper surface of the second substrate (200). Acoustic holes may be formed in the second region (200b). Acoustic holes may be placed in the second region (200b) by a full etching process on the second substrate (200), and the thickness of the region where the acoustic holes are excluded may be maintained without a separate etching process.

[0063] The third region (200c) is a region for arranging a signal processing element (500) and a capacitor (600), and can be arranged adjacent to the second region (100b) on the other side inside the first region (200a) with respect to the upper surface of the second substrate (200). A cavity (210) can be arranged in the third region (200c) by a pool etching process, and an interposer (800), which will be described later, can be arranged in the cavity (210).

[0064] A bonding sheet (700) is a means for bonding a first substrate (100) and a second substrate (200). The bonding sheet (700) is positioned between the upper surface of the first substrate (100) and the lower surface of the second substrate (200) to bond the first substrate (100) and the second substrate (200). The bonding sheet (700) may have a shape and size corresponding to the shape and size of the second substrate (200). Accordingly, the bonding sheet (700) may be formed to have a cavity corresponding to the cavity (210) of the second substrate (200), and depending on the design, may be formed in a shape corresponding to the shape of the first region (200a) of the second substrate (200).

[0065] The interposer (800) may be placed in a cavity (210) formed in the second substrate (200). In the case of a MEMS microphone according to the first embodiment of the present invention, a cavity (210) may be formed in a third region (200c) of the second substrate (200), and the interposer (800) may have a shape corresponding to the cavity (210) of the second substrate (200) and be inserted into the cavity (210) to be electrically connected to the first substrate (100).

[0066] A signal processing element (500) and a capacitor (600) may be disposed on the upper surface of the interposer (800). The interposer (800) may be electrically connected to the signal processing element (500) and the capacitor (600). In this case, the interposer (800) may be electrically connected to the signal processing element (500) and the capacitor (600) by solder balls, but there are no restrictions on the connection method. The signal processing element (500) and the capacitor (600) may be combined or mounted in a flip-chip form on the upper surface of the interposer (800).

[0067] The interposer (800) may include a plurality of pads, a plurality of connection circuits, and a plurality of vias for connecting a signal processing element (500) and a capacitor (600) on the upper surface. Below, the plurality of pads for electrically connecting the signal processing element (500) and the capacitor (600) on the upper surface (800a) of the interposer (800) are defined as second pads (810), the plurality of connection circuits are defined as second connection circuits (820a) and a plurality of second vias (830a).

[0068] The interposer (800) may be placed on the upper surface of the first substrate (100). The interposer (800) may be electrically connected to the first substrate (100). The lower surface of the interposer (800) may be electrically connected to the upper surface of the first substrate (100). In this case, the interposer (800) may be electrically connected to the first substrate (100) by solder balls, but there are no restrictions on the connection method. The lower surface of the interposer (800) may be combined or mounted in a flip-chip form on the upper surface of the first substrate (100).

[0069] The interposer (800) may include a plurality of pads, a plurality of connection circuits, and a plurality of vias for electrically connecting to a first pad formed on the upper surface of a first substrate (100) on the lower surface. Below, a plurality of pads for electrically connecting to the upper surface of the first substrate (100) on the lower surface (800b) of the interposer (800) are defined as a third pad (810b), a plurality of connection circuits (820b) as a third connection circuit, and a plurality of vias as a third via (830b). Here, the third via (830b) and the second via (820b) may overlap each other to form a single via.

[0070] The interposer (800) may have at least one insulating layer disposed between its upper and lower surfaces, and a plurality of metal layers disposed on the upper or lower surface of the at least one insulating layer, for example, a via may be formed in the at least one insulating layer of the interposer (800) to electrically connect the second pad (810a) and the third pad (810b). That is, the interposer (800) may electrically connect the second pad (810a) and the third pad (810b) through a via formed in the at least one insulating layer, and if the second pad (810a) and the third pad (810b) are not disposed in a position where they overlap each other, the second connecting circuit (820a) and the second via (830a) may electrically connect the second pad (810a) and the third pad (810b) through the third connecting circuit (820b) and the third via (830b).

[0071] The interposer (800) may further include an embedded capacitor (not shown). The interposer (800) may include one or more cap insulating layers among the stacked insulating layers and a metal layer disposed on the upper or lower surface of the cap insulating layer as an embedded capacitor. For example, the interposer (800) may include first to third metal layers and first and second insulating layers disposed between each metal layer, in which case a structure in which the second metal layer and the third metal layer and the second insulating layer disposed between them are used as cap insulating layers may operate as an embedded capacitor. For another example, the interposer (800) may include first to fourth metal layers and first to third insulating layers disposed between each metal layer, in which case a structure in which the second metal layer and the third metal layer and the second insulating layer disposed between them are used as cap insulating layers may operate as an embedded capacitor.

[0072] An embedded capacitor may include an insulating material corresponding to a cap insulating layer and a metal layer disposed on the upper or lower surface of the cap insulating layer. The metal layer may be disposed on the upper and lower surfaces of the insulating material, respectively, to surround the insulating material. The metal layer may be formed from a metallic material such as Cu or Au and function as an electrode, and the insulating material may include an insulating material having a high dielectric constant. BaTiO3 may be used as the insulating material, but is not limited thereto, and various insulating materials having high dielectric constants may be used without limitation.

[0073] The embedded capacitor can perform the role of a capacitor. Specifically, the embedded capacitor can be used for RF noise filtering because the internal insulating material acts as an insulator and the metal layer is electrically connected to the second and third pads of the interposer (800) through vias, thereby electrically connecting the interposer (800) to the first substrate (100). Accordingly, there is an effect of improving SNR and PSRR performance without placing a separate capacitor.

[0074] The embedded capacitor can be electrically connected to the first pad of the first substrate (100) through a via to remove RF noise.

[0075] A housing (400) and a MEMS structure (300) may be disposed on the second substrate (200), and a signal processing element (500) and a capacitor (600) may be disposed on an interposer (800) disposed in a cavity (210) of the second substrate (200). The capacitor (600) may be optionally disposed on the interposer (800) as needed.

[0076] A housing (400) is a means for being placed on the upper surface of a second substrate (200) and forming a receiving space inside. The housing (400) may be formed in a cover shape with an open bottom surface, and the receiving space may be formed by the bottom surface of the housing (400) being joined to the upper surface of the second substrate (200). Specifically, the housing (400) and the second substrate (200) may be joined by the housing (400) being adhered to the bottom surface of the housing (400) in the first region (200a) of the second substrate (200). The bottom surface of the housing (400) and the first region (200a) of the second substrate (200) may be joined by solder bonding, but the joining method is not limited and various joining methods may be performed.

[0077] The housing (400) may be composed of nickel silver or stainless steel (SUS). Nickel silver is a material containing 15-30% zinc and 10-20% nickel in copper, and allows for solder jointing without plating in its raw material state. Applying plating to the seating area of ​​the housing (400) can improve the solder joint adhesion. Ni+Au plating can be applied. Both electroless and electrolytic plating processes can be applied. Although stainless steel (SUS) contains Ni, the solder joint adhesion may decrease if plating is not performed. Therefore, plating can be applied. Unlike nickel silver, the plating adhesion on the surface of stainless steel may decrease when electroless plating is applied, so plating can be performed using an electrolytic plating process.

[0078] The MEMS structure (300) may be placed within a receiving space formed by a housing (400). The MEMS structure (300) may be placed on top of a second substrate (200) within the receiving space. The MEMS structure (300) may include a body (310), a backplate (330), and a diaphragm (320). The MEMS structure (300) may be placed in a second region (200b) of the second substrate (200), and the lower part of the MEMS structure (300) may be placed at a position adjacent to an acoustic hole (10).

[0079] The body (310) is a means for surrounding the acoustic hole formed in the second substrate (200) and forming a partition. The body (310) can be electrically connected to the signal processing element (500) and the first substrate (100) through an interposer (800). Additionally, an acoustic hole (360) communicating with the acoustic hole can be formed in the body (310). The body (310) can be directly connected to the second substrate (200), but if necessary, the body (310) can be directly connected to the first substrate (100) through the cavity (210) of the second substrate (200), and there are no limitations on this.

[0080] An acoustic hole (360) may be formed in the body (310). When the body (310) is coupled to the second substrate (200), the acoustic hole (10) formed in the first substrate (100) and the second substrate (200) and the acoustic hole (360) of the body (310) may be arranged to communicate with each other, and thus, sound from the outside may be designed to flow in through the acoustic hole (360).

[0081] The backplate (330) and the diaphragm (320) can be placed in an acoustic hole (360) formed in the body (310). The diaphragm (320) can vibrate due to the sound pressure of the sound when sound is introduced from the outside through the acoustic hole (360), and the backplate (330) can sense the acoustic signal by measuring the capacitance according to the vibration of the diaphragm (320). Additionally, the backplate (330) and the diaphragm (320) can be placed on the upper side based on the extension direction of the body (310). Although the backplate (330) is shown as being located above the diaphragm in the drawing, the diaphragm (320) may be located above the backplate (330).

[0082] One or more body pads for electrical connection may be formed on the upper surface of the body (310), although not shown. The body pads may be electrically connected to the backplate (330) and the diaphragm (320), and may be electrically connected to the interposer (800) via wires, etc. As the shape and material of the body pads are known technologies for electrical connection, a description thereof is omitted.

[0083] A signal processing element (500) may be placed on an interposer (800). The signal processing element (500) may be placed on the interposer (800) spaced apart from the MEMS structure (300). The signal processing element (500) may be placed on the interposer (800) spaced apart from the MEMS structure (300) on the third region (200c) of the second substrate (200) inside the housing (400), and may receive a signal from the MEMS structure (300) through the interposer (800). Since signal transmission between the MEMS structure (300) and the signal processing element (500) takes place in the receiving space formed by the housing (400), external interference is reduced, and thereby noise can be reduced.

[0084] The signal processing element (500) is electrically connected to the MEMS structure (300) and can process electrical signals sensed from the MEMS structure (300). The signal processing element (500) can be electrically connected to the MEMS structure (300) through the interposer (800). As the MEMS structure (300) and the interposer (800) are electrically connected, the signal processing element (500) can be electrically connected to the MEMS structure (300). For example, the signal processing element (500) may be soldered to the second pad (810a) of the interposer (800), and the body pad of the MEMS structure (300) may be electrically connected to the second pad (810a) of the interposer (800) through a wire. At this time, the second pad (810a) to which the signal processing element (500) is connected and the second pad (810a) to which the body pad of the MEMS structure (300) is connected may be the same or different from each other, and if different, the second pads (810a) may be electrically connected by the second connection circuit (820a). The signal processing element (500) may have a signal pad disposed therein for transmitting a signal to the interposer (800) through a solder ball.

[0085] The signal processing element (500) can be electrically connected to the first substrate (100). The signal processing element (500) can be electrically connected to the first pad (110) of the first substrate (100) through the interposer (800). For example, the signal processing element (500) and the second pad (810a) of the interposer (800) are electrically connected through solder ball bonding, and the third pad (810b) of the interposer (800) and the first pad (110) of the first substrate (100) are electrically connected through solder ball bonding, so that the first pad (110) of the first substrate (100) and the signal pad of the signal processing element (500) can be electrically connected through the second pad (810a) and the third pad (810b) of the interposer (800). In this case, the second pad (810a) and the third pad (810b) may be electrically connected through one or more of the second connection circuit (820a), the second via (830a), the third connection circuit (820b), and the third via (830b). The signal processed by the signal processing element (500) may be transmitted to the outside that requires the signal through the first pad (110) of the first substrate (100).

[0086] The signal processing element (500) can amplify a signal sensed in the MEMS structure (300). Here, the signal processing element (500) may include an Application-Specific Integrated Circuit (ASIC), but is not limited thereto. The signal processing element (500) may be formed as a single module or may be formed in the form of a chip. The signal processing element may include an ASIC and an En-cap that coats the ASIC.

[0087] A capacitor (600) may be optionally placed on the upper part of the interposer (800) as needed. When the capacitor (600) is placed, the PSRR performance, which is the aforementioned RF-related noise, and the PSR performance, which is power-related noise, may be improved. That is, noise-related performance such as SNR, PSRR, and PSR can be improved through the capacitor (600). The capacitor (600) may be electrically connected to the signal processing element (500). As a result, the capacitor (600) can remove noise during the signal processing process in the signal processing element (500).

[0088] A capacitor (600) is positioned on the interposer (800) of the third region (200c) of the second substrate (200) and can be electrically connected to a signal processing element (500) and a first substrate (100). The capacitor (600) can be electrically connected to a second pad of the interposer (800) and electrically connected to a signal processing element (500) and a first substrate (100) through the interposer (800). In this case, the second pad (810a) of the interposer (800) connected to the capacitor (600) can be electrically connected to one or more of the second pad (810a) of the interposer (800) connected to the signal processing element (500) and the third pad (810b) of the interposer (800) connected to the first substrate (100) through one or more of the second connection circuit (820a), the second via (830a), the third connection circuit (820b), and the third via (830b). In the case of MEMS microphones, since miniaturization is essential, there is often a lack of space for placing the capacitor (600), so the capacitor (600) is not placed in the circuit design, which causes a problem where the performance of SNR, PSR, and PSRR is degraded by power noise or RF noise. The MEMS microphone according to the first embodiment of the present invention has the effect of enabling improvement in all performance of SNR, PSR, and PSRR by mounting the capacitor (600) in a flip-chip form through an interposer (800), thereby securing placement space for the capacitor (600) and enabling miniaturization.

[0089] The MEMS microphone according to the first embodiment of the present invention can expand the area where the bonding sheet (700) is placed between the first substrate (100) and the second substrate (200) compared to the conventional one, thereby not only solving the problem of peeling between the first substrate (100) and the second substrate (200) but also increasing the bonding reliability.

[0090] In addition, by combining the signal processing element (500) and the capacitor (600) in a flip-chip form with the interposer (800), they are electrically connected to the first substrate (100) through the interposer (800). Therefore, compared to the case where the signal processing element (500) and the capacitor (600) are directly combined with the first substrate (100) without the interposer (800), damage to the signal processing element (500) or the capacitor (600) can be reduced, and the length of the wire used for wire bonding can be reduced, thereby reducing wire costs and resulting in an overall reduction in manufacturing costs.

[0091] In addition, since the design of the first pad, first connection circuit, and first via of the first substrate (100) can be simplified or omitted, the manufacturing process of the first substrate (100) is simplified, and the thickness of the substrate unit can be reduced compared to the conventional method. As the internal back chamber volume increases, the signal-to-noise ratio (SNR) is improved, and the dynamic range is increased.

[0092] In addition, by placing an embedded capacitor inside the interposer (800), the capacitor effect can be enjoyed without having to separately mount or place a capacitor to reduce noise generated by the power supply.

[0093] The second to fifth embodiments of the present invention are described below. For each component, redundant descriptions are omitted if they are structurally identical, and only the differing components are described.

[0094] FIG. 4 is a side view illustrating the structure of a MEMS microphone according to a second embodiment of the present invention, FIG. 5 is a top view illustrating the structure of a MEMS microphone according to a second embodiment of the present invention, and FIG. 6 is a drawing illustrating the substrate unit structure of a MEMS microphone according to a second embodiment of the present invention.

[0095] A MEMS microphone according to a second embodiment may include a first substrate (100), a second substrate (200), a MEMS structure (300), a housing (400), a signal processing element (500), a capacitor (600), a bonding sheet (700), and an interposer (800).

[0096] The second substrate (200) may include a cavity (210). In this case, the cavity (210) may be positioned to penetrate a second region (200b) that overlaps at least partially in a vertical direction with the region where the MEMS structure (300) is placed, and a third region (200c) that overlaps at least partially in a vertical direction with the region where the signal processing element (500) is placed. That is, a cavity (210) may be formed in the region where the second region (200b) and the second region (200c) are integrated.

[0097] The bonding sheet (700) may have a shape and size corresponding to the shape and size of the second substrate (200). Accordingly, the bonding sheet (700) may be formed to have a cavity corresponding to the cavity (210) of the second substrate (200), and depending on the design, may be formed to have a shape corresponding to the shape of the first region (200a) of the second substrate (200). The bonding sheet (700) may be disposed on the upper surface of the first substrate (100) and the lower surface of the first region (200a) of the second substrate (200) in a shape corresponding to the shape of the first region (200a) of the second substrate (200) to bond the first substrate (100) and the second substrate (200).

[0098] The interposer (800) may be placed in the cavity (210) on the first substrate (100). In this case, the size of the interposer (800) may have a size corresponding to the size of the cavity (210), and may have a larger size than the size of the interposer (800) of the MEMS microphone according to the first embodiment of the present invention.

[0099] An interposer (800) may have a MEMS structure (300), a signal processing element (500), and a capacitor (600) disposed on its upper surface. The interposer (800) may be electrically connected to the MEMS structure (300), the signal processing element (500), and the capacitor (600). In this case, the interposer (800) may be electrically connected to the MEMS structure (300), the signal processing element (500), and the capacitor (600) by solder balls, but there are no restrictions on the connection method. The MEMS structure (300), the signal processing element (500), and the capacitor (600) may be combined or mounted in a flip-chip form on the upper surface of the interposer (800).

[0100] The interposer (800) can be positioned in the form of a single substrate or a separated substrate so that the MEMS structure (300), the signal processing element (500), and the capacitor (600) are positioned on top. Specifically, the interposer (800) can be positioned inside a cavity (210) that integrates the second region (200b) and the third region (200c) into a single substrate, or alternatively, the interposer (800) can be positioned in the second region (200b) and the third region (200c) of the second substrate (200) respectively with two substrates.

[0101] When the interposer (800) is arranged separately, the interposer (800) may include a first interposer arranged in a second region (200b) of the second substrate (200) and a second interposer arranged in a third region (200c) of the second substrate (200). The first interposer may be arranged so that a MEMS structure (300) is electrically connected to the upper part, and the second interposer may be arranged so that a signal processing element (500) and a capacitor (600) are electrically connected to the upper part. When the interposer (800) is divided into a first interposer and a second interposer, the embedded capacitor included in the interposer (800) may also include a first embedded capacitor included in the first interposer and a second embedded capacitor included in the second interposer. In this case, since two embedded capacitors are placed, it can effectively have the effect of having two capacitors installed.

[0102] The interposer (800) may have one or more second pads (810a), second connection circuits (820a), and second vias (830a) disposed on the upper surface (800a), and one or more third pads (810b), third connection circuits (820b), and third vias (830b) disposed on the lower surface (800b). As the configuration has been described in the first embodiment, a redundant description is omitted.

[0103] One or more of the second pad (810a), second connection circuit (820a), and second via (830a) disposed in the interposer (800) may be electrically connected to the MEMS structure (300), signal processing element (500), and capacitor (600). Since the connection structure of the signal processing element (500) and capacitor (600) is the same as that of the first embodiment, the connection configuration of the MEMS structure (300) will be described.

[0104] One or more of the second pad (810a), second connection circuit (820a), and second via (830a) disposed in the interposer (800) may be electrically connected to the MEMS structure (300). In this case, the MEMS structure (300) may be electrically connected to the signal processing element (500) and the first substrate (100) by being electrically connected to the interposer (800). Specifically, a body pad disposed in the body (310) of the MEMS structure (300) is disposed on the lower side of the body (310) and electrically connected by contacting the second pad (810a) of the interposer (800), so that the MEMS structure (300) may be electrically connected to the signal processing element (500) and the first substrate (100) through the interposer (800). Since the MEMS structure (300) is electrically connected to the signal processing element (500) in a flip-chip form through an interposer (800) rather than by wire bonding, wire costs are reduced, resulting in a reduction in manufacturing costs. In the drawing, the MEMS structure (300) is shown in the shape of an inverted MEMS structure of a MEMS microphone according to one embodiment, but it is not limited to this; as long as a body pad is placed on the lower surface of the body (310) of the MEMS structure (300) and can be electrically connected to the interposer (800), there is no limitation on the shape.

[0105] According to the second embodiment, the MEMS microphone has the effect of reducing manufacturing costs by simplifying the structure and eliminating the need for separate wire bonding, as the interposer (800) is placed in the second region (200b) and the third region (200c) of the second substrate (200), thereby mounting the MEMS structure (300), signal processing element (500), and capacitor (600) in a flip-chip form and electrically connecting them to the first substrate (100).

[0106] In addition, by placing the interposer (800) in the cavity (210) area of ​​the second substrate (200), the rigidity of the first substrate (100) is supplemented, and at the same time, the MEMS microphone can be miniaturized, and as the back chamber volume increases, the signal-to-noise ratio (SNR) is improved and the dynamic range is increased.

[0107] In addition, when the interposer (800) is divided into a first interposer and a second interposer, the embedded capacitor also includes the first embedded capacitor and the second embedded capacitor, so it can have the effect of mounting two capacitors.

[0108] FIG. 7 is a side view illustrating the structure of a MEMS microphone according to a third embodiment of the present invention, and FIG. 8 is a top view illustrating the structure of a MEMS microphone according to a third embodiment of the present invention.

[0109] A MEMS microphone according to the third embodiment may include a first substrate (100), a second substrate (200), a MEMS structure (300), a housing (400), a signal processing element (500), a capacitor (600), a bonding sheet (700), and an interposer (800).

[0110] The second substrate (200) may include one or more cavities. The cavities may include a first cavity (210) for placing an interposer and a second cavity (220) for exposing a first pad of the first substrate (100) to the outside.

[0111] Additionally, the second substrate (200) may include a first region (200a), a second region (200b), a third region (200c), and a fourth region (200d). As previously described, the first to third regions (200a, 200b, 200c) will be described only with respect to the fourth region (200d). The fourth region (200d) is a region disposed between the first region (200a) and the third region (200c), and is a region for exposing the first pad (110) of the first substrate (100) to which the signal processing element (500) and / or capacitor (600) is electrically connected. Specifically, the fourth region (200d) is a region that overlaps at least partially in a vertical direction with the first pad (110) connected to the signal processing element (500) and / or capacitor (600). That is, the second region (200b), the third region (200c), and the fourth region (200d) may be sequentially arranged from one side based on the area excluding the first region (200a) on the upper surface of the second substrate (200). Meanwhile, the arrangement method of the second region (200b), the third region (200c), and the fourth region (200d) of the second substrate (200) is not limited to the example described above, and it is sufficient if they are arranged within the first region (200a).

[0112] The first cavity (210) may be placed in the second region (200b). In this case, an interposer (800) may be placed in the first cavity (210), and a MEMS structure (300) may be placed on top of the interposer (800) placed in the second region (200b).

[0113] The second cavity (220) may be placed in the fourth region (200d), the first pad (110) placed on the first substrate (100) may be exposed to the outside through the second cavity (220), and the signal processing element (500) and capacitor (600) may be electrically connected to the first substrate (100) by being connected to the first pad (110) by wire bonding.

[0114] The interposer (800) may be placed in a second region (200b) of the second substrate (200). Specifically, the interposer (800) may be placed in a first cavity (210) formed in the second region (200b), and a MEMS structure (300) may be placed on top of the interposer (800).

[0115] The interposer (800) can be electrically connected to the MEMS structure (300). One or more of the second pad (810), second connection circuit, and second via disposed in the interposer (800) can be electrically connected to the MEMS structure (300). The body pad disposed on the lower surface of the body (310) of the MEMS structure (300) and the second pad (810) of the interposer (800) can come into contact, thereby electrically connecting the interposer (800) and the MEMS structure (300).

[0116] The MEMS structure (300) can be electrically connected to a signal processing element (500). Specifically, the MEMS structure (300) can be electrically connected to the signal processing element (500) through an interposer (800). A body pad formed on the lower surface of the body (310) of the MEMS structure (300) and a second pad of the interposer (800) can be electrically connected through solder ball bonding, and a second pad (810) of the interposer (800) connected to the MEMS structure (300) can be electrically connected to the signal processing element (500) through a second connection circuit. The interposer (800) and the signal processing element (500) can be connected through wire bonding, and the MEMS structure (300) can be electrically connected to the signal processing element (500) through the interposer (800). In the drawing, the MEMS structure (300) is in the shape of an inverted MEMS structure of a MEMS microphone according to one embodiment, but it is not limited thereto, and there is no limitation on the shape as long as a body pad is placed on the lower surface of the body (310) of the MEMS structure (300) and can be electrically connected to the interposer (800).

[0117] The MEMS microphone according to the third embodiment can minimize the length of the wire used for bonding in the process of connecting the interposer (800) to the MEMS structure (300) and connecting the interposer (800) and the signal processing element (500) by wire bonding, and thereby reduce the cost of raw materials by reducing the cost of the wire, which has the effect of reducing the cost of the product.

[0118] FIG. 9 is a side view illustrating the structure of a MEMS microphone according to a fourth embodiment of the present invention.

[0119] A MEMS microphone according to the fourth embodiment may include a first substrate (100), a second substrate (200), a MEMS structure (300), a housing (400), a signal processing element (500), a capacitor (600), a bonding sheet (700), and an interposer (800).

[0120] The second substrate (200) may include a first region (200a), a second region (200b), a third region (200c), and a fourth region (200d). As the first to third regions (200a, 200b, 200c) are described in one embodiment and the fourth region (200d) is described in a third embodiment, a redundant description is omitted.

[0121] The second substrate (200) may include a cavity (220). Since the cavity (220) has the same structure and effect as the second cavity of the MEMS microphone according to the third embodiment, a redundant description is omitted. That is, the second substrate (200) has only a cavity (220) for exposing the first pad of the first substrate (100), and a cavity for placing a separate interposer (800) is not formed.

[0122] The interposer (800) may be placed on the upper surface of the second substrate (200). The interposer (800) may be placed on the lower surface of the MEMS structure (300). That is, the interposer (800) may be placed between the second substrate (200) and the MEMS structure (300). A second pad formed on the upper surface of the interposer (800) may be connected to the body (310) of the MEMS structure (300). In this case, a body pad may be formed on the upper surface of the body (310) of the MEMS structure (300) and electrically connected to the signal processing element (500) through wire bonding.

[0123] The MEMS microphone according to the fourth embodiment has the effect of increasing the volume of the front chamber inside the MEMS structure (300) by means of an interposer (800). As the volume of the front chamber into which sound is introduced inside the MEMS structure (300) increases, the low-frequency response of the MEMS microphone is improved, as well as the sensitivity is increased and external noise or noise can be reduced.

[0124] FIG. 10 is a side view illustrating the structure of a MEMS microphone according to a fifth embodiment of the present invention.

[0125] A MEMS microphone according to the fifth embodiment may include a first substrate (100), a second substrate (200), a MEMS structure (300), a housing (400), a signal processing element (500), a capacitor (600), a bonding sheet (700), and an interposer (800).

[0126] In the MEMS microphone of the fifth embodiment, only the position of the interposer may be changed from that of the MEMS microphone of the fourth embodiment. The interposer (800) may be placed on the upper part of the body (310) of the MEMS structure (300). In this case, the third pad of the interposer (800) and the body pad formed on the upper part of the body (310) of the MEMS structure (300) may be electrically connected by contacting each other, and the second pad of the interposer (800) and the signal pad of the signal processing element (500) may be electrically connected through wire bonding.

[0127] According to the fifth embodiment, the MEMS microphone has the effect of reducing the cost of the product by reducing raw material costs, as the wire length can be designed shorter than in the conventional method because the position of the second pad to be wire-bonded with the signal processing element (500) can be arbitrarily designed as the interposer (800) is placed on the upper part of the MEMS structure (300).

[0128] Those skilled in the art related to the embodiments described above will understand that they may be implemented in modified forms without departing from the essential characteristics of the description. Therefore, the disclosed methods should be considered in an illustrative rather than a restrictive sense. The scope of the invention is defined by the claims, not by the foregoing description, and all variations within the scope of equivalence should be interpreted as being included in the invention.

Claims

First substrate; A second substrate laminated on the first substrate and having a cavity formed therein; An interposer disposed inside the cavity and coupled with the first substrate; A housing coupled to the second substrate and forming an internal receiving space; A MEMS structure disposed on the upper part of the second substrate in the above receiving space; and A signal processing element is included on the upper surface of the second substrate in the receiving space, spaced apart from the above MEMS structure; One or more of the above MEMS structure and the above signal processing element are coupled to the above MEMS microphone on the interposer. In Article 1, The second substrate above is, A first area where the above housing is placed, A second region where the above MEMS structure is disposed and It consists of a third region in which the above signal processing element is placed, and The above cavity is a MEMS microphone disposed in one or more of the second region and the third region. In Article 2, The above cavity is disposed in the above second region, and A MEMS microphone in which the above MEMS structure is coupled to the above interposer. In Article 2, The above cavity is disposed in the above third region, and A MEMS microphone in which the above signal processing element is coupled to the above interposer. In Article 2, The above cavity is positioned to penetrate the second region and the third region, and A MEMS microphone having the MEMS structure and the signal processing element disposed on the interposer. In Article 5, The above interposer is, A first interposer disposed in the second region of the cavity; and It includes a second interposer positioned spaced apart from the first interposer and positioned in the third region of the cavity, The MEMS structure is disposed on the first interposer, and A MEMS microphone in which the signal processing element is disposed on the second interposer. In Article 6, The above-mentioned first interposer includes a first embedded capacitor, and The above second interposer is a MEMS microphone including a second embedded capacitor. In Article 1, The first substrate is a MEMS microphone comprising a 2Metal COF substrate. In Article 1, The first substrate includes a plurality of first pads on its upper surface, and The above interposer comprises a second pad disposed on an upper surface for electrically connecting one or more of the MEMS structure and the signal processing element, and a third pad disposed on a lower surface that contacts the first pad, forming a MEMS microphone. In Article 1, The above interposer includes a plurality of insulating layers, one or more vias and pads disposed between the insulating layers, and One or more of the insulating layers above are MEMS microphones comprising embedded capacitors.

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