Microphone package and mounting structure thereof

There are provided a microphone package and a mounting structure thereof, allowing for an increase in a back volume, the microphone package including: a package substrate; an acoustic element mounted on the package substrate and having a space formed in a lower portion thereof; and at least one electronic component mounted on the package substrate and having a space formed in a lower portion thereof, wherein the package substrate includes an acoustic volume connecting the space of the acoustic element and the space of the electronic component.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No. 10-2013-0141958 filed on Nov. 21, 2013, with the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

BACKGROUND

The present disclosure relates to a microphone package and a mounting structure thereof, and more particularly, to a microphone package allowing for ease in forming a back volume, and a mounting structure thereof.

Recently, as volumes of electronic products such as cellular phones, notebook computers, and the like have been reduced and performance requirements for the electronic product increased, the volume of components installed in electronic products has gradually been reduced, while performances thereof have been required to be improved.

In accordance with the trend, many products in the field of microphone products have been developed as main components. An example of the microphone product is a micro electro mechanical systems (MEMS) microphone mass-produced using semiconductor manufacturing technologies.

In a microphone according to the related art, a back volume is formed below or behind a MEMS sound device. The term “back volume” may refer to a space opposite to a surface on which soundwaves and MEMS sound components meet, and may also be referred to as a ‘ cavity back or back side cavity’. In general, it is known that when cavity volume of a back volume is increased, microphone sensitivity is further increased, and a better frequency response curve may be achieved.

However, in a microphone package according to the related art, back volume is formed as a very narrow space and it is difficult to increase volume of the back volume in a structure thereof.

RELATED ART DOCUMENT

SUMMARY

An aspect of the present disclosure may provide a microphone package and a mounting structure thereof, allowing for an increase in a back volume.

According to an aspect of the present disclosure, a microphone package may include a package substrate; an acoustic element mounted on the package substrate and having a space formed in a lower portion thereof; and at least one electronic component mounted on the package substrate and having a space formed in a lower portion thereof, wherein the package substrate includes an acoustic volume connecting the space of the acoustic element and the space of the electronic component.

The acoustic volume may be formed in a tunnel shape in the package substrate.

The acoustic volume may include a tunnel portion formed in the package substrate; and tunnel entrances extending from both ends of the tunnel portion and opened to the outside of the package substrate.

The acoustic element and the electronic component may be mounted on the package substrate to block the tunnel entrances, respectively.

The space formed in the acoustic element and the space formed in the electronic component, and the acoustic volume formed in the package substrate may be connected to form a back volume.

The acoustic volume may include a plurality of through holes penetrating through the package substrate.

The acoustic element and the electronic component may be mounted on the package substrate to block entrances of the through holes.

A ring-shaped partition part may be formed on a lower surface of the package substrate in such a manner that the through holes are disposed in an inner portion of the ring-shaped partition part.

The partition part may be adhered to a main substrate on which the package substrate is mounted, to separate an internal space and an external space.

The package substrate may include a tunnel portion formed in the package substrate in a tunnel form and connecting the through holes to each other.

At least one groove may be formed in a lower surface of the package substrate between the through holes.

The groove formed in the lower surface of the package substrate may partially include the through holes and connect the through holes to each other.

The microphone package may further include an auxiliary substrate adhered to the lower portion of the package substrate.

The auxiliary substrate may include a through portion formed therein and connected to the through holes formed in the package substrate.

The microphone package may further include a partition part interposed between the package substrate and the auxiliary substrate and formed in a ring shape to separate an internal space and an external space, wherein the through holes are connected to the internal space of the partition part.

According to another aspect of the present disclosure, a mounting structure of a microphone package may include a main structure; a package substrate including a plurality of through holes formed therein and mounted on the main substrate; an acoustic element mounted on the package substrate to block one of the through holes and having a space formed in a lower portion thereof; and at least one electronic component mounted on the package substrate to block another of the through holes and having a space formed in a lower portion thereof.

The mounting structure may further include a partition part interposed between the package substrate and the main substrate to surround the through holes.

The main substrate may include at least one groove formed in one surface thereof disposed in an internal space of the partition part.

According to another aspect of the present disclosure, a mounting structure of a microphone package may include a main substrate; an auxiliary substrate including a through portion formed therein and mounted on the main substrate; a package substrate including a plurality of through holes formed therein and mounted on the auxiliary substrate; an acoustic element mounted on the package substrate to block one of the through holes and having a space formed in a lower portion thereof; and at least one electronic component mounted on the package substrate to block another of the through holes and having a space formed in a lower portion thereof.

The mounting structure may further include a first partition part interposed between the package substrate and the auxiliary substrate to surround the through holes; and a second partition part interposed between the auxiliary substrate and the main substrate to surround a circumference of the through portion.

DETAILED DESCRIPTION

FIG. 1is a cross-sectional view of a microphone package100according to an exemplary embodiment of the present disclosure.

Referring toFIG. 1, the microphone package100according to the exemplary embodiment may include a package substrate110, an acoustic element120, an electronic component160, and a cover130. In addition, the microphone package100may further include other devices required for an operation of the acoustic element120.

The microphone package100configured as described above may be installed in a portable electronic component, may detect sound containing voice information, and may convert the detected sound into electrical signals.

Hereinafter, a main structure of the microphone package100will be described.

As the package substrate110, various types of substrate such as a ceramic substrate, a printed circuit board, a flexible substrate, and the like, well known in the art to which the present disclosure pertains, may be used. In addition, mounting electrodes13for mounting the acoustic element120or the electronic component160or wiring patterns for electrically connecting the mounting electrodes13to each other may be formed on at least one surface of the package substrate110.

The package substrate110according to the exemplary embodiment may be a multilayer substrate including a plurality of layers, and circuit patterns (not shown) for forming electrical connections may be formed between the layers. However, embodiments of the present disclosure are not limited thereto. That is, the package substrate110may be formed as a single substrate.

The package substrate110according to the exemplary embodiment may include conductive vias14electrically connecting the mounting electrodes13formed on opposite surfaces of the package substrate110and circuit patterns formed within the package substrate110.

External connection pads16may be formed on a lower surface of the package substrate110according to the exemplary embodiment. The external connection pads16may be used for electrical connection with a main substrate1or an auxiliary substrate and may be adhered to external terminals30.

In addition, at least one or more electronic components may be mounted or installed on the package substrate110. Here, the electronic components may include both a passive component and an active component.

The package substrate110according to the exemplary embodiment may include an acoustic volume50that forms a back volume of the acoustic element120. The acoustic volume50may be formed in various shapes as long as the acoustic volume50may form a back volume. In the exemplary embodiment, the acoustic volume50is formed in a tunnel shape.

In more detail, the acoustic volume50according to the exemplary embodiment may include a tunnel portion51formed in the package substrate110, and at least two tunnel entrances52extending from both ends of the tunnel portion51and opened to the outside of the package substrate110.

To this end, the package substrate110may be a multilayer substrate in which at least three layers110a,110b, and110care stacked. In detail, the package substrate110may include a first substrate layer110aon which the acoustic element120and the electronic component160to be described later are mounted, a second substrate layer110cforming a bottom surface of the package substrate110, and a third substrate layer110binterposed between the first substrate layer110aand the second substrate layer110c.

Accordingly, the tunnel entrances52may be formed in the first substrate layer110aand the tunnel portion51may be formed in the third substrate layer110b.

The package substrate110may be mounted on the main substrate1and may be electrically connected to the main substrate1through a plurality of the external terminals30. Here, the external terminals30may be solder balls, solder bumps, or the like but are not limited thereto.

The exemplary embodiment may be modified in various forms. For example, the lower surface of the package substrate110comes into surface contact with a surface of the main substrate1to be adhered thereto and then is electrically connected to the main substrate1via bonding wire.

The acoustic element120may be a general silicon condenser microphone device and may be manufactured by micro electro mechanical systems (MEMS).

The acoustic element120may convert sound into electrical signals using capacitance that varies according to movement of a vibration plate vibrating by sound. To this end, the acoustic element120may include a diaphragm and a back plate, and have a groove122formed in a lower surface of the acoustic element120, the groove122extending inwardly or upwardly of the acoustic element120.

Here, the groove122may be aback volume (also, referred to as “a back side cavity”) included in the acoustic element120.

In addition, the acoustic element120may be mounted to block a tunnel entrance52a(hereinafter, a first tunnel entrance52a) on one surface of the package substrate110. In this case, the first tunnel entrance52amay be adhered to the acoustic element120so as to contact the lower surface of the acoustic element120, that is, an entrance of the groove122.

Thus, when the acoustic element120is mounted on the package substrate110, the first tunnel entrance52ais blocked by the acoustic element120, thereby forming a space including the back volume of the acoustic element120.

The electronic component160may be a customized electronic component160such as an application-specific integrated circuit (ASIC). However, embodiments of the present disclosure are not limited thereto. That is, the electronic component160may include other general electronic components, and semiconductor devices.

In addition, the electronic component160may have a groove162formed in a lower surface of the electronic component160, the groove162extending inwardly or upwardly of the electronic component160. Here, the groove162may be a back volume (back side cavity) that is additionally formed in the electronic component160.

Conventionally, electronic components are mounted on a package substrate, but are not used to expand back volume and do not include back volume spaces. However, the electronic component160according to the exemplary embodiment includes a back volume space and expands the overall size of a back volume of the microphone package100due to the presence of the back volume space.

When a thickness (or a height) of the electronic component160is low, a depth of the groove162formed in the electronic component160is small, and thus, the volume of the groove162may be very small. Accordingly, the electronic component160according to the exemplary embodiment may be formed to have a mounting height corresponding to that of the acoustic element120. For example, the electronic component160may have the same mounting height as the acoustic element120or may be configured to have a maximum mounting height as high as possible in an internal space of the cover130.

In addition, the electronic component160may be mounted to block another tunnel entrance52b(hereinafter, a second entrance52b) on one surface of the package substrate110. In this case, the second entrance52bmay be adhered to the electronic component160so as to contact the lower surface of the electronic component160, that is, an entrance of the groove162.

Thus, when the electronic component160is mounted on the package substrate110, the second entrance52bis blocked by the electronic component160, thereby forming a space including the back volume of the electronic component160.

The acoustic element120and the electronic component160may be electrically connected via wiring patterns, bonding wire, or the like, of the package substrate110.

The cover130may be formed of a metallic material. However, the cover130is not necessarily formed of a metallic material, and the cover130may be formed of mixture including a metallic powder.

The cover130may be formed to cover the acoustic element120and the electronic component160. Through the cover130, the acoustic element120and the electronic component160may be protected from harmful electromagnetic waves.

At least one acoustic hole132may be formed in the cover130. The acoustic hole132may be used as a path for introducing or discharging sound.

The microphone package100according to the present disclosure configured as described above may be formed in such a manner that the groove162is formed in a lower portion of the electronic component160while the groove122is formed in a lower portion of the acoustic element120, thereby serving as a back volume.

In addition, the acoustic volume50is formed in a tunnel shape in the package substrate110and connects spaces122and162formed in the acoustic element120and the electronic component160to each other.

Accordingly, an overall size of the back volume may be increased while maintaining an overall volume of the microphone package100, thereby enhancing performance of the microphone package100.

The microphone package according to the present disclosure is not limited to the foregoing embodiment and may be modified in various manners.

FIG. 2is a schematic cross-sectional view of a microphone package200according to another embodiment of the present disclosure.FIG. 3is a cross-sectional view of the microphone package200taken long line P-P ofFIG. 2.

Referring toFIGS. 2 and 3, the microphone package200according to the exemplary embodiment is similar to the aforementioned embodiment except for the structure of the package substrate110. Accordingly, detailed descriptions of elements the same as those of previously detailed embodiments are omitted, and the structure of the package substrate110will be described in detail.

The microphone package200according to the exemplary embodiment is configured in such a manner that at least two through holes55are formed in the package substrate110. The through holes55may be formed by penetrating through the package substrate110in a vertical direction. However, embodiments of the present disclosure are not limited thereto. That is, the through holes55may be formed in a diagonal direction or in a direction that varies in the package substrate110.

The acoustic element120and the electronic component160are mounted on one surface of the package substrate110. In this case, the acoustic element120and the electronic component160are respectively mounted on entrances of the through holes55to block one ends of the through holes55.

A partition part70connecting the main substrate1and the package substrate110is formed on the other surface of the package substrate110. The partition part70may include all the other ends of the through holes55within an inner portion thereof. Thus, the through holes55may be blocked by the partition part70from the outside and are formed as an encapsulated space.

The partition part70may be formed as a barrier rib using conductive adhesives, resin adhesives, or the like. That is, the partition part70may be formed of various types of material as long as the partition part70is interposed between the package substrate110and the main substrate1to separate an internal space from an external space.

An internal space of the partition part70is used as a back volume (back side cavity).

That is, the back volume of the microphone package200according to the exemplary embodiment may include spaces122and162that are basically included in the acoustic element120and the electronic component160, spaces formed by the through holes55, and spaces formed by the partition part70between the package substrate110and the main substrate1.

Accordingly, the size of back volume may be further increased compared with a microphone package according to the related art.

In the exemplary embodiment, the internal space formed by the partition part70is formed in a circular form as shown inFIG. 3. However, embodiments of the present disclosure are not limited thereto. That is, as necessary, the internal space may be formed in various manners.

FIGS. 4 to 7are views illustrating a method of manufacturing the microphone package illustrated inFIG. 2.

With reference toFIGS. 4 to 7, the method of manufacturing the microphone package will now be described. First, as illustrated inFIG. 4, the acoustic element120and the electronic component160are mounted on the package substrate110in which the through holes55are formed, and the microphone package coupled to the cover130and the main substrate1are prepared.

Then, as illustrated inFIG. 5, conductive adhesives S1 and S2 such as solder paste are applied to one surface of the main substrate1. In this case, the conductive adhesives S1 and S2 may be applied to all of positions (indicated as S1) in which the external terminals30of the microphone package are mounted and positions (indicated as S2) in which the partition part70is formed.

That is, the partition part70according to the exemplary embodiment may be formed by the conductive adhesive for forming electrical connections and adherence between the microphone package200and the main substrate1.

Then, the microphone package200is accommodated on the main substrate1, and then the conductive adhesives are melted and hardened, such that a mounting process may be completed, as illustrated inFIG. 2.

Accordingly, the external terminals30of the microphone package200are electrically connected to the main substrate1, and the partition part70is formed between the main substrate1and the package substrate110of the microphone package200to complete an encapsulated back volume.

As illustrated inFIG. 5, the partition part70may be formed by applying the conductive adhesive S2 in a continuous ring shape along a shape of the partition part70illustrated inFIG. 3. However, embodiments of the present disclosure are not limited thereto.

For example, as illustrated inFIG. 6, the conductive adhesive S2 may be applied in a broken line shape along positions in which the partition part70is discontinuously formed. In this case, portions to which the conductive adhesive S2 is not applied are connected to each other during a melting and hardening process of the conductive adhesive S2, and thus, the partition part70may be finally formed in a continuous ring shape.

In the aforementioned manufacturing method, the partition part70may be formed using a conductive adhesive. However, the present disclosure is not limited thereto.

For example, in the aforementioned operation ofFIG. 5, the conductive adhesive S1 may be only applied to the positions in which the external terminals30are mounted, and a resin S3 is applied or adhesive tape S3 is adhered to the positions in which the partition part70is formed, whereby the partition part70may be formed. In addition, various applications may be used. For example, the partition part70may be formed using a pre-manufactured ring structure.

FIGS. 8 and 9are schematic cross-sectional views illustrating modified examples of the microphone package illustrated inFIG. 3.

Referring toFIG. 8, a microphone package300according to the exemplary embodiment is similar to the microphone package100illustrated inFIG. 1in that the tunnel portion51is formed in the package substrate110. In this case, a back volume may be further increased in an amount equal to a space of the tunnel portion51.

Referring toFIG. 9, in the package substrate110of a microphone package400according to the exemplary embodiment, a groove57may be formed between through holes52.

In the mounting structure of the microphone package400according to the exemplary embodiment, a groove2may be formed in the main substrate1, as well as a groove being formed in the microphone package400. Here, the groove2of the main substrate1is formed in an internal space partitioned by the partition parts70.

When the groove57is formed in the lower surface of the package substrate110or the groove2is formed in the main substrate1, a back volume may be further increased in an amount equal to spaces formed by the grooves57and2.

FIG. 9illustrates a case in which the microphone package400is configured in such a manner that the grooves formed in the package substrate110partially include the two through holes52and connect the through holes52to each other. However, the present disclosure is not limited thereto. That is, various applications may be used. For example, a plurality of grooves may be formed between the through holes52or different grooves are further formed in a single groove.

In addition, in the exemplary embodiment, the respective grooves are formed in the microphone package400and the main substrate1. However, the present disclosure is not limited thereto. That is, a groove may be formed only in any one of the microphone package400and the main substrate1.

FIG. 10is a schematic view of a microphone package500according to another embodiment of the present disclosure.

Referring toFIG. 10, a mounting structure of the microphone package500according to the exemplary embodiment includes an auxiliary substrate20.

The auxiliary substrate20may be interposed between the microphone package500and the main substrate1and may include an insulating layer21and external terminals30b.

The auxiliary substrate20is disposed below the package substrate110of the microphone package500and is coupled to the package substrate110.

As the auxiliary substrate20, various types of substrate such as a ceramic substrate, a printed circuit board, a flexible substrate, or the like, well known in the art to which the present disclosure pertains, may be used in a similar manner to the package substrate110.

Electrode pads24may be formed on opposite surfaces of the insulating layer21. The electrode pads24formed on an upper surface of the auxiliary substrate20are used for electrical connection with external terminals30aof the package substrate110. In addition, the electrode pads24formed on a lower surface of the auxiliary substrate20are used for coupling with the external terminals30bof the auxiliary substrate20.

Conductors25for electrical connection between the electrode pads24formed on the opposite surfaces may be formed in the insulating layer21.

The external terminals30bof the auxiliary substrate20may be formed on the lower surface of the insulating layer21and the electrode pads24may be electrically and physically connected to the main substrate1.

The auxiliary substrate20according to the exemplary embodiment may be a multilayer substrate including a plurality of layers, and circuit patterns (not shown) for electrical connections between the layers may be formed. However, the present disclosure may not be limited thereto. That is, the auxiliary substrate20may be formed as a single layer package substrate.

The auxiliary substrate20according to the exemplary embodiment may be formed by preparing a plurality of insulating layers in which vias are formed and then stacking the insulating layers to electrically connect the vias, or by stacking a plurality of insulating layers, forming through holes penetrating through all of the insulating layers, and then, forming vias in the through holes. Alternatively, the auxiliary substrate20may be formed in various manners by preparing one resin layer (e.g., epoxy, or the like) and forming a plurality of metallic posts (e.g., a Cu post) penetrating through the resin layer to be surrounded by the resin layer.

A through portion22having a through hole form is formed in the auxiliary substrate20according to the exemplary embodiment. The through portion22is used as a space for expanding the size of the back volume. Accordingly, the through portion22may be formed to have a size and a shape such that it is connected to all of entrances of the through holes55formed in the package substrate110.

In addition, in a similar manner to the aforementioned embodiment, the partition parts70are formed on the upper portion and lower portion of the auxiliary substrate20. A first partition part70ais interposed between the package substrate110and the auxiliary substrate20to surround the through holes55, thereby comparting a back volume space. A second partition part70bis interposed between the auxiliary substrate20and the main substrate1to surround the through portion22, thereby comparting a back volume space.

The mounting structure of the microphone package including the auxiliary substrate according to the exemplary embodiment may use a through hole space of the auxiliary substrate as well as through holes formed in the package substrate as a back volume, thereby ensuring a significantly increased back volume.

As set forth above, according to exemplary embodiments of the present disclosure, a microphone package is configured in such a manner that a groove is formed in a lower portion of an electronic component as well as formed in a lower portion of an acoustic element, thereby being used as a back volume.

In addition, an acoustic volume is formed in a package substrate in the form of a tunnel or through holes so as to connect spaces formed between the acoustic element and the electronic component.

Accordingly, the size of the back volume may be increased while maintaining an overall volume of the microphone package, thereby enhancing performance of the microphone package.