CN117459863A

CN117459863A - Micro-electromechanical packaging structure

Info

Publication number: CN117459863A
Application number: CN202211246560.6A
Authority: CN
Inventors: 张咏翔; 吴嘉殷; 李岳刚
Original assignee: Merry Electronics Shenzhen Co ltd
Current assignee: Merry Electronics Shenzhen Co ltd
Priority date: 2022-07-26
Filing date: 2022-10-12
Publication date: 2024-01-26
Also published as: TW202404891A

Abstract

The invention provides a micro-electromechanical packaging structure which comprises a substrate, a sensing module, a waterproof layer and a cover body. The substrate is provided with a first surface, a second surface and an acoustic hole penetrating through the first surface and the second surface. The sound hole is provided with an upper opening and a lower opening, and the caliber of the lower opening is larger than that of the upper opening. The sensing module is configured on the first surface of the substrate and covers the upper opening. The waterproof layer is arranged on the second surface of the substrate and covers the lower opening. The waterproof layer has a plurality of pores. The plurality of fine holes communicate with the sound holes. The cover body is configured on the first surface and covers the sensing module.

Description

Micro-electromechanical packaging structure

Technical Field

The present disclosure relates to microelectromechanical devices, and particularly to a microelectromechanical package structure.

Background

The micro-electromechanical microphone comprises a vibrating diaphragm and a back electrode plate, which are manufactured on a silicon chip and are used for receiving sound waves and converting the sound waves into electric signals. Microelectromechanical microphones have been used in a wide variety of notebook computers, smart phones, and various portable electronic products. In recent years, dust-proof and waterproof functions of portable electronic products are also becoming important.

In the existing micro-electromechanical microphone, in order to avoid the damage of the sound receiving module caused by the entry of water drops in the environment from the sound holes, a plurality of fine holes are required to be formed on the substrate position corresponding to the sound receiving module, and the fine holes can avoid the entry of water drops into the micro-electromechanical microphone, but the energy loss is increased when the sound waves are transmitted to the sensing module due to the too small pore diameter of the fine holes, so that the sound receiving efficiency of the micro-electromechanical microphone is affected.

Disclosure of Invention

The invention provides a micro-electromechanical packaging structure which is suitable for micro-electromechanical microphones, wherein sound holes with different calibers are formed on a substrate, and a larger number of fine holes can be contained on one side with the larger calibers, so that energy loss when sound waves are transmitted to a sensing module is reduced, and the sound receiving efficiency of the micro-electromechanical microphones is maintained.

The invention relates to a micro-electromechanical packaging structure, which comprises a substrate, a sensing module, a waterproof layer and a cover body. The substrate is provided with a first surface, a second surface and an acoustic hole penetrating through the first surface and the second surface. The sound hole is provided with an upper opening and a lower opening, and the caliber of the lower opening is larger than that of the upper opening. The sensing module is configured on the first surface of the substrate and covers the upper opening. The waterproof layer is arranged on the second surface of the substrate and covers the lower opening. The waterproof layer has a plurality of pores. The plurality of fine holes communicate with the sound holes. The cover body is configured on the first surface and covers the sensing module.

In an embodiment of the invention, the plurality of pores are distributed in a region of the vertical projection of the lower opening and beyond a region of the vertical projection of the upper opening.

In an embodiment of the invention, the acoustic port has a stepped side surface extending perpendicularly from the first surface to the second surface.

In an embodiment of the invention, the sound hole has an inclined side surface extending obliquely from the first surface to the second surface.

In an embodiment of the invention, the upper opening of the sound hole extends vertically from the first surface by a first thickness, and the sound hole extends obliquely from the first thickness to the second surface by a second thickness, so as to form the lower opening.

In an embodiment of the invention, the sensing module has a chamber correspondingly connected to the sound hole, and an inner diameter of the chamber is matched with an aperture of an upper opening of the sound hole.

In an embodiment of the present invention, a distance between the upper opening and the lower opening is greater than 50um, and an alternative embodiment is between 50um and 75 um.

In an embodiment of the present invention, the pore diameter of each pore is between 20um and 50um, and an alternative embodiment is between 34um and 42um, and the number of the pores is more than 8, and an alternative embodiment is between 31 and 48.

In an embodiment of the invention, the sensing module further includes at least one electrode, and the electrode is disposed on an outer surface of the waterproof layer away from the substrate.

In an embodiment of the invention, the sensing module further includes at least one electrode, and the electrode is disposed on a top surface of the cover.

In an embodiment of the present invention, the waterproof layer further includes a height-increasing layer disposed outside the waterproof layer and having openings corresponding to the plurality of pores.

Based on the above, the micro-electromechanical packaging structure of the invention is suitable for micro-electromechanical microphones, sound holes with different calibers are formed on a substrate, meanwhile, a waterproof layer is arranged on the substrate, the waterproof layer is provided with a plurality of pores and is positioned in the sound holes, sound waves in the environment are sequentially transmitted from the pores to the sensing module through the sound holes, one side with large sound hole diameter corresponds to the pores, so that the number of pores of the waterproof layer in the sound hole range is increased, and one side with small sound hole diameter corresponds to the sensing module, so that the first surface of the substrate has enough space to carry the sensing module. The micro-electromechanical microphone can reduce the energy loss when the sound wave is transmitted to the sensing module through the increase of the number of the pores under the condition of not increasing the whole volume so as to maintain the sound receiving efficiency of the micro-electromechanical microphone.

In addition, the plurality of pores of the waterproof layer can effectively prevent water drops from entering the sound holes to cause the damage of the sensing module.

Drawings

Fig. 1 is a schematic plan view of a mems package structure according to a first embodiment of the present invention.

Fig. 2 is a schematic plan view of an acoustic hole and a plurality of fine holes of the mems package structure of fig. 1.

FIG. 3 is a schematic plan view of the MEMS package structure of FIG. 1 in combination with a raised layer.

Fig. 4 is a schematic plan view of a mems package structure according to a second embodiment of the present invention.

Fig. 5 is a schematic plan view of a microelectromechanical package structure according to a third embodiment of the invention.

Fig. 6 is a schematic plan view of a mems package structure according to a fourth embodiment of the present invention.

[ symbolic description ]

100. 100A, 100B, 100C, 100D: a microelectromechanical package structure;

110: a substrate;

111. 111b: a first surface;

112. 112b: a second surface;

113. 113b, 113c: an acoustic aperture;

1131. 1131c: an upper opening;

1132. 1132c: a lower opening;

1133. 1133b: a side surface;

120. 120a, 120b, 120d: a sensing module;

121. 121b: a chamber;

122: a vibrating diaphragm;

123. 123a, 123d: an electrode;

130. 130a: a waterproof layer;

131. 131a: fine pores;

132: an outer surface;

140. 140d: a cover body;

150a: an elevation layer;

151a: opening holes;

w: acoustic waves;

d1, D2: caliber;

t1: a first thickness;

t2: a second thickness.

Detailed Description

In order that the above objects, features and advantages of the invention will be readily understood, a more particular description of the invention will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the invention, whereby the invention is not limited to the specific embodiments disclosed below.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present invention, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

It will be understood that when an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like are used herein for illustrative purposes only and are not meant to be the only embodiment.

Fig. 1 is a schematic plan view of a mems package structure according to a first embodiment of the present invention. Fig. 2 is a schematic plan view of an acoustic hole and a plurality of fine holes of the mems package structure of fig. 1. FIG. 3 is a schematic plan view of the MEMS package structure of FIG. 1 in combination with a raised layer.

Referring to fig. 1, the mems package structure of the present invention is suitable for mems microphone, and is formed by packaging a substrate, a sensing module, an Application Specific Integrated Circuit (ASIC), and a housing. The substrate is, for example, a circuit board and has metal lines, and the sensing module and the asic are electrically coupled to the metal lines of the substrate. In addition, the application specific integrated circuit and the sensing module are mutually coupled through wire bonding.

Referring to fig. 1, the microelectromechanical packaging structure 100 of the present embodiment includes a substrate 110, a sensing module 120, a waterproof layer 130, and a cover 140.

The substrate 110 has a first surface 111, a second surface 112, and an acoustic hole 113 penetrating the first surface 111 and the second surface 112. The acoustic port 113 has an upper opening 1131 and a lower opening 1132, and the caliber D2 of the lower opening 1132 is larger than the caliber D1 of the upper opening 1131, wherein the acoustic port 113 is used for transmitting the acoustic wave W in the environment.

Further, the acoustic hole 113 has a stepped side 1133 extending perpendicularly from the first surface 111 to the second surface 112, and the distance between the upper opening 1131 and the lower opening 1132 is greater than 50um, and in an alternative embodiment, is between 50um and 75 um. Wherein, the caliber D1 of the sound hole 113 extends vertically from the first surface 111 to between 25um and 37.5um, and the caliber D2 of the sound hole 113 extends vertically from 25um to 37.5um to the second surface 112 to form the stepped side 1133.

The sensing module 120 is disposed on the first surface 111 of the substrate 110 and covers the upper opening 1131 of the acoustic hole 113. The sensing module 120 is a microphone sensor and has a chamber 121 and a diaphragm 122. The chamber 121 is correspondingly communicated with the acoustic hole 113, and the size and shape of the inner diameter of the chamber 121 are matched with the caliber D1 of the upper opening 1131 of the acoustic hole 113.

Additionally, when the sound wave W enters the chamber 121 through the sound hole 113, the sound wave W generates a pressure difference in the chamber 121 to cause the vibration of the diaphragm 122, and the diaphragm 122 converts the vibration into an electronic signal, and then sequentially transmits the electronic signal to the asic and the speaker to output the sound signal.

Referring to fig. 1 and 2, the waterproof layer 130 is disposed on the second surface 112 of the substrate 110 and covers the lower opening 1132 of the sound hole 113. The waterproof layer 130 has a plurality of pores 131. The plurality of fine holes 131 communicate with the acoustic holes 113 and are distributed in the range of the lower opening 1132. In detail, the plurality of fine holes 131 are distributed in the area of the lower opening 1132 perpendicularly projected and are beyond the area of the upper opening 1131 perpendicularly projected, wherein the plurality of fine holes 131 are uniformly distributed in the area of the lower opening 1132. The cover 140 is disposed on the first surface 111 and covers the sensing module 120.

Referring to fig. 2, in the present embodiment, the pore diameter of each pore 131 is between 20um and 50um, and in an alternative embodiment between 34um and 42um, and the number of the plurality of pores 131 is 31 to 48. In the embodiment, the pore diameter of the pores 131 is less than or equal to 42um to achieve the waterproof standard and not to cause excessive damping of sound waves, but the pore diameter of the pores 131 cannot be less than 34um, if the pore diameter of the pores 131 is less than 34um, the energy loss of sound waves passing through each pore 131 is increased, which is not beneficial to the sound wave sensing of the sensing module 120. The number of the plurality of pores 131 is adjusted to be 31 to 48 according to the size of the caliber D2 of the lower opening 1132, and is uniformly distributed in the area of the lower opening 1132.

For example, when the diameter D2 of the lower opening 1132 of the sound hole 113 is 800um, the number of the fine holes 131 is 31, and when the diameter D2 of the lower opening 1132 of the sound hole 113 is 1000mm, the number of the fine holes 131 is 48.

In other embodiments, the number of pores may be less than 31 or greater than 48, depending on the size of the sound hole, and the present invention is not limited to the number of pores.

Referring to fig. 1, the sensing module 120 includes at least one electrode 123. In the present embodiment, the number of the at least one electrode 123 is plural, and the plurality of electrodes 123 are disposed on the outer surface 132 of the waterproof layer 130 away from the substrate 110.

Additionally, the electrodes 123 are coupled to a motherboard of a computer, a notebook computer or a smart phone to supply power to the sensing module 120.

Referring to fig. 3, the microelectromechanical packaging structure 100A of the present embodiment further includes a raised layer 150A, which is disposed outside the waterproof layer 130A and has an opening 151a corresponding to the plurality of pores 131 a. The elevation layer 150a is used to support the waterproof layer 130a, thereby preventing the waterproof layer 130a from directly contacting the motherboard or other machine components, which would damage the plurality of pores 131a of the waterproof layer 130 a. In addition, the plurality of electrodes 123a of the sensing module 120a are disposed on a side of the elevation layer 150a away from the waterproof layer 130 a.

Referring to fig. 4, the micro-electromechanical packaging structure 100B of the present embodiment is different from the micro-electromechanical packaging structure 100 shown in fig. 1 in that the acoustic hole 113B has an inclined side 1133B extending obliquely from the first surface 111B to the second surface 112B. In detail, the width of the inclined side surface 1133b of the sound hole 113b extends gradually from the upper opening 1131b toward the lower opening 1132b, so that the second surface of the substrate has enough open space and the first surface of the substrate has enough carrying space. As the acoustic wave W enters the acoustic aperture 113b from the lower opening 1132b, it will pass through the upper opening 1131b along the tapered width inclined side 1133b and into the cavity 121b of the sensing module 120 b.

Referring to fig. 5, the micro-electromechanical packaging structure 100C of the present embodiment is different from the micro-electromechanical packaging structure 100 shown in fig. 1 in that the upper opening 1131C of the acoustic hole 113C extends perpendicularly from the first surface 111C by a first thickness T1, and the acoustic hole 113C extends obliquely from the first thickness T1 by a second thickness T2 to the second surface 112C, so as to form a lower opening 1132C. In detail, the inner diameter of the cavity 121c is matched with the caliber D1 of the upper opening 1131c of the sound hole 113c, and the width of the sound hole 113c extends gradually from the first thickness T1 toward the lower opening 1132c, so that the second surface of the substrate has enough open space and the first surface of the substrate has enough carrying space.

Referring to fig. 6, the micro-electromechanical packaging structure 100D of the present embodiment is different from the micro-electromechanical packaging structure 100 shown in fig. 1 in that the sensing module 120D includes at least one electrode 123D. The number of the at least one electrode 123d is plural, and the plurality of electrodes 123d are disposed on the top surface of the cover 140 d. Additionally, the electrodes 123d are coupled to a motherboard of a computer, a notebook computer or a smart phone to supply power to the sensing module 120d.

In summary, the microelectromechanical packaging structure of the present invention is suitable for microelectromechanical microphones, and acoustic holes with different diameters are formed on a substrate, and meanwhile, a waterproof layer is disposed on the substrate, the waterproof layer has a plurality of pores and is located in the acoustic holes, sound waves in the environment sequentially pass through the acoustic holes from the pores to the sensing module, a side with a larger acoustic hole diameter corresponds to the pores, so as to increase the number of pores of the waterproof layer in the acoustic hole range, and a side with a smaller acoustic hole diameter corresponds to the sensing module, so that the first surface of the substrate has enough space to carry the sensing module. The micro-electromechanical microphone can reduce the energy loss when the sound wave is transmitted to the sensing module through the increase of the number of the pores under the condition of not increasing the whole volume so as to maintain the sound receiving efficiency of the micro-electromechanical microphone.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims

1. A microelectromechanical package structure, comprising:

the substrate is provided with a first surface, a second surface and an acoustic hole penetrating through the first surface and the second surface, wherein the acoustic hole is provided with an upper opening and a lower opening, and the caliber of the lower opening is larger than that of the upper opening;

a sensing module configured on the first surface of the substrate and covering the upper opening;

a waterproof layer disposed on the second surface of the substrate and covering the lower opening, wherein the waterproof layer has a plurality of pores, and the pores are communicated with the sound holes; and

the cover body is configured on the first surface and covers the sensing module.

2. The microelectromechanical package of claim 1, wherein a plurality of the pores are distributed within and beyond the area of the vertical projection of the lower opening.

3. The microelectromechanical package structure of claim 1, wherein the acoustic aperture has a stepped side extending perpendicularly from the first surface to the second surface.

4. The microelectromechanical package structure of claim 1, wherein the acoustic aperture has an angled side extending diagonally from the first surface to the second surface.

5. The microelectromechanical package of claim 1, wherein the upper opening of the acoustic aperture extends vertically from a first surface by a first thickness, and the acoustic aperture extends obliquely from the first thickness by a second thickness to the second surface to form the lower opening.

6. The microelectromechanical package structure of claim 1, wherein the sensing module has a cavity corresponding to the acoustic port, and an inner diameter of the cavity matches a caliber of the upper opening of the acoustic port.

7. The microelectromechanical package of claim 1, wherein the upper opening and the lower opening are spaced apart by a distance of between 50um and 75 um.

8. The microelectromechanical package of claim 1, wherein the pore size of each pore is between 34um and 42um, and the number of pores is between 31 and 48.

9. The microelectromechanical package structure of claim 1, wherein the sensing module further comprises at least one electrode disposed on an outer surface of the waterproof layer remote from the substrate.

10. The microelectromechanical package structure of claim 1, wherein the sensing module further comprises at least one electrode disposed on a top surface of the lid.

11. The microelectromechanical package of claim 1, further comprising a raised layer disposed outside the waterproof layer and having openings corresponding to the plurality of pores.