TW202404891A - Micro-electromechanical packaging structure - Google Patents

Abstract

A micro-electromechanical packaging structure including a substrate, a sensing module, a water-proof layer, and a cover is provided. The substrate has a first surface, a second surface, and an acoustic hole penetrating the first surface and the second surface. The acoustic hole has an upper opening and a lower opening, and an aperture of the lower opening is larger than an aperture of the upper opening. The sensing module is disposed on the first surface of the substrate and covers the upper opening. The water-proof layer is disposed on the second surface of the substrate and covers the lower opening. The water-proof layer has a plurality of fine holes. The fine holes are communicated with the acoustic hole. The cover is disposed on the first surface and covers the sensing module.

Description

Microelectromechanical packaging structure

The present invention relates to a microelectromechanical component, and in particular to a microelectromechanical packaging structure.

A microelectromechanical microphone includes a diaphragm and a back plate, which are made on a silicon chip to receive sound waves and convert them into electrical signals. Microelectromechanical microphones have been widely used in notebook computers, smart phones and various portable electronic products. In recent years, the dustproof and waterproof functions of portable electronic products have also begun to receive attention.

In order to prevent existing micro-electro-mechanical microphones from damaging the sound-receiving module caused by water droplets in the environment entering through the sound hole, multiple pores need to be formed on the substrate of the corresponding sound-receiving module. These pores can prevent water droplets from entering the micro-electro-mechanical microphone. , but because the aperture of the pores is too small, this increases the energy loss when the sound wave is transmitted to the sensing module, thereby affecting the sound collection performance of the microelectromechanical microphone.

The present invention provides a microelectromechanical packaging structure suitable for microelectromechanical microphones. Sound holes with different diameters are formed on the substrate. The side with a larger diameter can accommodate more pores, thereby reducing the time required for sound waves to be transmitted to a sensing module. The energy loss is to maintain the pickup performance of the microelectromechanical microphone.

The microelectromechanical packaging structure of the present invention includes a substrate, a sensing module, a waterproof layer and a cover. The substrate has a first surface, a second surface and a sound hole penetrating the first surface and the second surface. The sound hole has an upper opening and a lower opening, and the diameter of the lower opening is larger than the diameter of the upper opening. The sensing module is disposed on the first surface of the substrate and covers the opening. The waterproof layer is disposed on the second surface of the substrate and covers the lower opening. The waterproof layer has multiple pores. Multiple pores connect to the sound pore. The cover is disposed on the first surface and covers the sensing module.

In one embodiment of the present invention, the plurality of pores are distributed within the vertical projection area of the lower opening and beyond the vertical projection area of the upper opening.

In one embodiment of the present invention, the above-mentioned acoustic hole extends vertically from the first surface to the stepped side of the second surface.

In an embodiment of the present invention, the above-mentioned acoustic hole extends obliquely from the first surface to the inclined side of the second surface.

In an embodiment of the present invention, the upper opening of the sound hole extends perpendicularly from the first surface to a first thickness, and the sound hole obliquely extends from the first thickness to the second surface to form a second thickness. Open your mouth.

In an embodiment of the present invention, the above-mentioned sensing module has a chamber correspondingly connected to the sound hole, and an inner diameter of the chamber matches the diameter of the upper opening of the sound hole.

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

In one embodiment of the present invention, the diameter of each of the above-mentioned pores is between 20um and 50um, and a preferred embodiment is between 34um and 42um, and the number of the plurality of pores is more than 8. In a preferred embodiment, 31 to 48.

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

In an embodiment of the present invention, the above-mentioned sensing module further includes at least one electrode, and the electrode is arranged on a top surface of the cover.

In an embodiment of the present invention, an increasing layer is further included, which is arranged outside the waterproof layer and has an opening corresponding to a plurality of pores connected thereto.

Based on the above, the microelectromechanical packaging structure of the present invention is suitable for microelectromechanical microphones. Sound holes with different diameters are formed on the substrate. At the same time, a waterproof layer is configured on the substrate. The waterproof layer has multiple pores and is opposite to the sound hole. The environment The sound waves in the sound wave are sequentially transmitted from the pores through the sound holes to the sensing module. The side with the larger diameter of the sound hole corresponds to multiple pores to increase the number of pores in the waterproof layer within the range of the sound hole. The side with the smaller diameter of the sound hole One side of the substrate is correspondingly connected to the sensing module, so that the first surface of the substrate has enough space to carry the sensing module. The microelectromechanical microphone can reduce the energy loss when sound waves are transmitted to the sensing module by increasing the number of pores without increasing the overall volume, thereby maintaining the sound collection performance of the microelectromechanical microphone.

In addition, the multiple pores in the waterproof layer can effectively prevent water droplets from entering the sound hole and causing damage to the sensing module.

FIG. 1 is a schematic plan view of the microelectromechanical packaging structure according to the first embodiment of the present invention. FIG. 2 is a schematic plan view of an acoustic hole and a plurality of pores of the microelectromechanical packaging structure of FIG. 1 . FIG. 3 is a schematic plan view of the microelectromechanical packaging structure of FIG. 1 combined with an increased layer.

Referring to Figure 1, the microelectromechanical packaging structure of the present invention is suitable for microelectromechanical microphones and is packaged by a substrate, a sensing module, an application specific integrated circuit (ASIC) and a casing. The substrate is, for example, a circuit board and has metal circuits, and the sensing module and the application-specific integrated circuit are electrically coupled to the metal circuits of the substrate. In addition, the application-specific integrated circuit and the sensing module are coupled to each other through wire bonding.

Referring to FIG. 1 , the microelectromechanical packaging structure 100 of this 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 a sound hole 113 penetrating the first surface 111 and the second surface 112 . The sound hole 113 has an upper opening 1131 and a lower opening 1132, and the diameter D2 of the lower opening 1132 is larger than the diameter D1 of the upper opening 1131. The sound hole 113 is used to transmit the sound wave W in the environment.

Furthermore, the sound hole 113 has a stepped side surface 1133 extending vertically 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 the preferred embodiment is between 50um and 75um. The range is between 50um and 75um. The diameter D1 of the sound hole 113 extends vertically from the first surface 111 to between 25um and 37.5um, and the diameter D2 of the sound hole 113 extends vertically from 25um to 37.5um to the second surface 112 to form a stepped side surface 1133 .

The sensing module 120 is disposed on the first surface 111 of the substrate 110 and covers the upper opening 1131 of the sound hole 113 . The sensing module 120 is a microphone sensor and has a chamber 121 and a diaphragm 122 . The chamber 121 is correspondingly connected to the sound hole 113 , and the size and shape of an inner diameter of the chamber 121 match the diameter D1 of the upper opening 1131 of the sound hole 113 .

In addition, 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. The diaphragm 122 converts this vibration into an electronic signal, and then the electrons are The signals are sequentially transmitted to the application-specific integrated circuit and the speaker to output audio.

Referring to FIGS. 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 . A plurality of pores 131 communicate with the sound hole 113 and are distributed within the range of the lower opening 1132 . In detail, the plurality of pores 131 are distributed within the vertical projection area of the lower opening 1132 and beyond the vertical projection area of the upper opening 1131 , wherein the plurality of pores 131 are evenly distributed within 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 Figure 2, in this embodiment, the diameter of each pore 131 is between 20um and 50um, and in a preferred embodiment, between 34um and 42um, and the number of the plurality of pores 131 is between 31 and 48. In this embodiment, the aperture of the pores 131 needs to be less than or equal to 42um to meet the waterproof standard and will not cause excessive sound wave damping. However, the aperture of the pores 131 cannot be less than 34um. If the aperture of the pores 131 is less than 34um, it will increase the sound waves passing through. The energy loss occurs when the pores 131 are formed, which is not conducive to the acoustic wave sensing of the sensing module 120 . The number of the plurality of pores 131 is adjusted to 31 to 48 according to the size of the diameter D2 of the lower opening 1132, and is evenly 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 800 um, the number of pores 131 is 31. When the diameter D2 of the lower opening 1132 of the sound hole 113 is 1000 mm, the number of pores 131 for 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. The present invention does not limit the number of pores.

Referring to FIG. 1 , the sensing module 120 includes at least one electrode 123 . In this embodiment, the number of at least one electrode 123 is multiple, and the multiple electrodes 123 are arranged on an outer surface 132 of the waterproof layer 130 away from the substrate 110 .

In addition, the plurality of electrodes 123 are used to be coupled to the motherboard of a computer, a laptop or a smartphone, thereby supplying power to the sensing module 120 .

Referring to FIG. 3 , the microelectromechanical packaging structure 100A of this embodiment further includes an increased layer 150 a , which is arranged outside the waterproof layer 130 a and has an opening 151 a correspondingly connected to a plurality of pores 131 a . The increased layer 150a is used to support the waterproof layer 130a, thereby preventing the waterproof layer 130a from directly contacting the motherboard or other mechanical components, thereby causing damage to the multiple pores 131a of the waterproof layer 130a. In addition, the plurality of electrodes 123a of the sensing module 120a are arranged on the side of the increasing layer 150a away from the waterproof layer 130a.

Referring to Figure 4, the microelectromechanical packaging structure 100B of this embodiment is different from the microelectromechanical packaging structure 100 shown in Figure 1. The difference is that the sound hole 113b has an inclined side 1133b that extends obliquely from the first surface 111b to the second surface 112b. . Specifically, the width of the inclined side surface 1133b of the sound hole 113b gradually increases from the upper opening 1131b toward the lower opening 1132b, so that while the second surface of the substrate retains sufficient opening space, the first surface of the substrate also has sufficient opening space. of passenger space. When the sound wave W enters the sound hole 113b from the lower opening 1132b, it will pass through the upper opening 1131b along the inclined side 1133b with tapering width, and enter the cavity 121b of the sensing module 120b.

Referring to Figure 5, the microelectromechanical packaging structure 100C of this embodiment is different from the microelectromechanical packaging structure 100 shown in Figure 1. The difference is that the upper opening 1131c of the sound hole 113c extends perpendicularly from the first surface 111c by a first thickness T1, and The sound hole 113c extends diagonally from the first thickness T1 to a second thickness T2 to the second surface 112c to form a lower opening 1132c. In detail, the inner diameter of the cavity 121c matches the diameter D1 of the upper opening 1131c of the sound hole 113c, and the width of the sound hole 113c gradually increases from the first thickness T1 toward the direction of the lower opening 1132c, so that the second thickness of the sound hole 113c increases. While sufficient opening space is maintained on the surface, the first surface of the substrate also has sufficient loading space.

Referring to FIG. 6 , the microelectromechanical packaging structure 100D of this embodiment is different from the microelectromechanical packaging structure 100 shown in FIG. 1 . The difference is that the sensing module 120d includes at least one electrode 123d. The number of at least one electrode 123d is multiple, and the multiple electrodes 123d are arranged on a top surface of the cover 140d. In addition, the plurality of electrodes 123d are used to be coupled to the motherboard of a computer, a notebook computer or a smartphone, thereby supplying power to the sensing module 120d.

To sum up, the microelectromechanical packaging structure of the present invention is suitable for microelectromechanical microphones. Sound holes with different diameters are formed on the substrate. At the same time, a waterproof layer is configured on the substrate. The waterproof layer has multiple pores and is opposite to the sound hole. , the sound waves in the environment are sequentially transmitted from the pores through the sound holes to the sensing module. The side with the larger diameter of the sound hole corresponds to multiple pores to increase the number of pores in the waterproof layer within the sound hole range. The sound hole The side with the smaller diameter is connected to the sensing module, so that the first surface of the substrate has enough space to carry the sensing module. The microelectromechanical microphone can reduce the energy loss when sound waves are transmitted to the sensing module by increasing the number of pores without increasing the overall volume, thereby maintaining the sound collection performance of the microelectromechanical microphone.

In addition, the multiple pores in the waterproof layer can effectively prevent water droplets from entering the sound hole and causing damage to the sensing module.

100, 100A, 100B, 100C, 100D: Microelectromechanical packaging structure 110:Substrate 111, 111b: first surface 112, 112b: Second surface 113, 113b, 113c: Sound hole 1131, 1131c: upper opening 1132, 1132c: lower opening 1133, 1133b: side 120, 120a, 120b, 120d: sensing module 121, 121b: Chamber 122:Diaphragm 123, 123a, 123d: electrode 130, 130a: waterproof layer 131, 131a: fine pores 132:Outer surface 140, 140d: Cover 150a: Adding a new floor 151a: opening W: sound wave D1, D2: caliber T1: first thickness T2: second thickness

FIG. 1 is a schematic plan view of the microelectromechanical packaging structure according to the first embodiment of the present invention. FIG. 2 is a schematic plan view of an acoustic hole and a plurality of pores of the microelectromechanical packaging structure of FIG. 1 . FIG. 3 is a schematic plan view of the microelectromechanical packaging structure of FIG. 1 combined with an increased layer. FIG. 4 is a schematic plan view of the microelectromechanical packaging structure of the second embodiment of the present invention. FIG. 5 is a schematic plan view of a microelectromechanical packaging structure according to a third embodiment of the present invention. FIG. 6 is a schematic plan view of the microelectromechanical packaging structure of the fourth embodiment of the present invention.

100: Microelectromechanical packaging structure

110:Substrate

111: First surface

112: Second surface

113: Sound hole

1131: Upper opening

1132:Lower opening

1133:Side

120: Sensing module

121: Chamber

122:Diaphragm

123:Electrode

130:Waterproof layer

131: fine pores

132:Outer surface

140: Cover

W: sound wave

D1, D2: caliber

Claims (11)

A microelectromechanical packaging structure, including: A substrate has a first surface, a second surface and a sound hole penetrating the first surface and the second surface, wherein the sound hole has an upper opening and a lower opening, and the diameter of the lower opening is larger than the upper opening. The diameter of the opening; a sensing module, disposed on the first surface of the substrate and covering the upper opening; A waterproof layer is disposed on the second surface of the substrate and covers the lower opening, wherein the waterproof layer has a plurality of pores connected to the sound hole; and A cover is disposed on the first surface and covers the sensing module. The microelectromechanical packaging structure as claimed in claim 1, wherein the pores are distributed within the vertical projection area of the lower opening and beyond the vertical projection area of the upper opening. The microelectromechanical packaging structure as claimed in claim 1, wherein the acoustic hole has a stepped side extending vertically from the first surface to the second surface. The microelectromechanical packaging structure as claimed in claim 1, wherein the acoustic hole extends obliquely from the first surface to the inclined side of the second surface. The microelectromechanical packaging structure of claim 1, wherein the upper opening of the sound hole extends perpendicularly from the first surface to a first thickness, and the sound hole extends diagonally from the first thickness to a second thickness. second surface to form the lower opening. The microelectromechanical packaging structure of claim 1, wherein the sensing module has a cavity corresponding to the sound hole, and an inner diameter of the cavity matches the diameter of the upper opening of the sound hole. The microelectromechanical packaging structure as claimed in claim 1, wherein the distance between the upper opening and the lower opening is between 50um and 75um. The microelectromechanical packaging structure as claimed in claim 1, wherein the pore diameter of each of the pores is between 34um and 42um, and the number of the pores is between 31 and 48. The microelectromechanical packaging structure according to claim 1, wherein the sensing module further includes at least one electrode, the electrode is arranged on an outer surface of the waterproof layer away from the substrate. The microelectromechanical packaging structure according to claim 1, wherein the sensing module further includes at least one electrode, and the electrode is arranged on a top surface of the cover. The microelectromechanical packaging structure as described in claim 1 further includes an increasing layer, which is arranged outside the waterproof layer and has an opening corresponding to the pores.

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