JP6736829B2 - Transducer device and manufacturing method thereof - Google Patents

Description

The present invention relates to a transducer device and a method of manufacturing the same, and more particularly, to a MEMS (Micro Electro Mechanical System) device that performs conversion between a physical quantity and electricity, and also relates to a transducer device packaged on a chip scale and a method of manufacturing the same.

FIG. 9 shows the configuration of a silicon package microphone device which is an example of a conventional transducer device. In FIG. 9, 41 is a substrate made of silicon, 42 is a fixed electrode, 43 is a movable electrode, 44 is a conversion unit (transducer) having the fixed electrode 42 and the movable electrode 43, 45 is an amplification of a signal from the conversion unit 44, etc. , 46 is a bonding wire, 47 is an acoustic port (opening), 48 is a lid made of silicon, 49 is a back chamber, 50 is a through hole via (TSV), and 51 is an external terminal.

In such a microphone device, when the movable electrode 43 vibrates due to sound pressure from the acoustic port 47, the change in capacitance at this time is captured by the conversion unit 44, and the signal from this conversion unit 44 is amplified by the signal processing circuit 45. As a result, voice can be output as an electric signal (Patent Document 1).

By the way, the microphone device shown in FIG. 9 has a structure in which the conversion unit 44 formed by the MEMS element and the signal processing circuit 45 are connected and mounted by the bonding wire 46 on the substrate 41. It is also possible to mount 45 chips by flip chip connection. The flip chip connection is superior to the connection using the bonding wire 46 in that the height and the density can be reduced.

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The flip-chip connection is superior to the connection using the bonding wire, but when the conversion unit 44 is flip-chip connected on the substrate 41, a gap is generated between the conversion unit 44 and the substrate 41. However, there is a problem that sound leaks from this gap and the acoustic characteristics deteriorate.

An object of the present invention is to solve the above problems and provide a transducer device capable of preventing sound leakage.

In order to achieve the above object, the invention according to claim 1 of the present application comprises a first substrate having an opening for connecting the outside and the inside, and a second substrate having a cavity, wherein the opening and the cavity are combined. In a transducer device in which a conversion unit having a fixed electrode and a movable electrode is arranged between the first substrate and the second substrate, the first substrate and the second substrate are made of silicon. , A flip-chip connection part for mounting the conversion part on one of the first substrate or the second substrate to form an electrical connection, a support for the conversion part, and the conversion part. A region that communicates the opening and the cavity between the first substrate and the first substrate or between the support of the conversion unit and the second substrate on which the conversion unit is mounted via the flip-chip connection. characterized in that it comprises a sound leak preventing joint for closing the.

The invention according to the claims 2 provides a method of manufacturing a transducer apparatus having a converter unit having a fixed electrode and the movable electrode, the unit region to form a transducer apparatus of the first wafer, openings for connecting the external and internal Forming a cavity in the unit area of the second wafer, and mounting the conversion unit in the unit area of either one of the first wafer or the second wafer. Forming a flip chip connection portion for electrical connection , and at the same time forming a sound leakage preventing joint between the first wafer or the second wafer and the support of the conversion portion , The step of joining so as to close the gap between the support of the conversion part formed by connection and the first wafer or the second wafer; and the conversion part between the opening and the cavity. Bonding the first wafer and the second wafer so as to seal the same, and cutting the bonded first wafer and the second wafer into individual transducer devices. And are included.

Since the transducer device of the present invention includes the sound leakage preventing joint portion in the conversion portion mounted on the substrate by flip-chip connection, it is possible to prevent sound leakage generated from the gap between the conversion portion and the substrate, and improve acoustic characteristics. be able to.

Further, this sound leakage preventing joint can be formed very easily because it can be formed at the same time as the step of mounting the converter on the substrate by flip-chip connection.

It is explanatory drawing of a manufacturing process of the transducer apparatus of the 1st Example of this invention. It is an explanatory view of a manufacturing process of a transducer device of a 1st example of the present invention. It is an explanatory view of a manufacturing process of a transducer device of a 1st example of the present invention. It is an explanatory view of a manufacturing process of a transducer device of a 1st example of the present invention. It is a figure explaining the transducer apparatus of the 2nd Example of this invention. It is a figure explaining the transducer apparatus of the 3rd Example of this invention. It is a figure explaining the transducer apparatus of the 4th Example of this invention. It is a figure explaining the transducer apparatus of the 1st Example of this invention. It is a figure explaining the conventional transducer device.

The transducer device according to the present invention is provided with the sound leakage prevention joint portion in the conversion portion flip-chip connected to the wiring portion on the substrate. According to this structure, it is possible to provide the transducer device capable of preventing the sound leakage generated from the gap between the conversion unit and the substrate. Hereinafter, examples of the present invention will be described according to manufacturing steps.

A first embodiment of the present invention will be described. This embodiment is a top port type in which external terminals and acoustic ports (openings) are provided on different surfaces.

First, the first substrate 11 is prepared. Here, as the first substrate 11, a silicon substrate used for manufacturing a normal semiconductor device is used. The insulating film 12 is formed on the surface of the first substrate 11. Further, a conductive film is laminated on the insulating film 12 and is patterned by the usual photolithography method to form a wiring layer. Here, for example, a ring-shaped joining terminal is also formed so as to surround an acoustic port (opening) formed in a later step. After that, the protective film 13 is formed on the wiring layer, and a part thereof is removed to expose the electrode pads 14 to 16 and the ring-shaped bonding terminal 17. Then, the bonding terminal 18 is formed by depositing a metal bonding material on the electrode pad 16 (FIG. 1a).

Next, an acoustic port (opening) 19 is formed at a desired position by a dry etching method (FIG. 1b).

A conversion unit (transducer) 23 including a fixed electrode 20, a movable electrode 21, and a support 22 and a signal processing circuit 24 for performing signal processing such as amplification are prepared. A projecting electrode 25 is formed on an electrode (not shown) provided on the support 22 of the conversion unit 23, faces the ring-shaped joining element 17 formed on the first substrate 11 on the support 22, and is a movable electrode. A ring-shaped joining terminal 26 is also formed along the edge of 21. The joint terminal 26 is not electrically joined to the conversion unit 23. Further, the protruding electrode 27 is also formed on the electrode (not shown) provided in the signal processing circuit 24. The converter 23 and the signal processing circuit 24 are mounted on the first substrate 11 by flip-chip connection. This connection can be formed by applying, for example, ultrasonic vibration to the protruding electrode 25 formed on the support 22 and the electrode pad 14 provided on the first substrate 11. Simultaneously with this flip-chip connection, the ring-shaped joint terminal 26 and the ring-shaped joint terminal 17 provided on the first substrate 11 are connected. By connecting in this manner, a sound leakage preventing joint portion 28 that fills the gap between the support 22 and the first substrate 11 is formed (FIG. 1d). The above-mentioned connection by application of ultrasonic vibration may be connection by heat pressurization or connection by a conductive adhesive.

Next, the second substrate 31 to be the lid is prepared. Here, as the second substrate 31, a silicon substrate used for manufacturing a normal semiconductor device is used. A resist pattern is formed on the surface of the second substrate 31, and the second substrate 31 is etched to form deep through holes. After that, an oxide film is formed on the inner surface of the through hole. Next, a through hole via (TSV) 32 is formed by embedding a conductive material in the through hole. As the filling, there are a method of filling a metal material by a plating method and a method of filling a silicon material to which an impurity is added (FIG. 2a).

Next, the insulating film 33 is formed on the surface of the second substrate 31. After that, the insulating film 33 on the surface of the through hole via 32 is removed to form an opening, the through hole via 32 is exposed, and the external terminal 34 connected to this exposed portion is formed (FIG. 2b).

Next, the back surface of the second substrate 31 is etched to form the back chamber 35 (FIG. 2C).

After that, a metal bonding material is formed on the entire back surface of the second substrate 31. Next, the metal bonding material directly under the through hole via is partially etched to separate the through hole via terminal 36. The metal bonding material separated from the through-hole via terminal 36 by this separation functions as the shield film 37 (FIG. 2d).

After that, as shown in FIG. 3, the conversion unit 23 and the signal processing circuit 24 mounted on the upper surface of the first substrate 11 are covered with a back chamber 35, and the second substrate 31 is overlapped with a lid to form a first substrate. The bonding terminal 18 of the substrate 11 and the through-hole via terminal 36 of the second substrate 31 are bonded by the conductive adhesive 38 so as to be connected. FIG. 4 shows a state in which the first substrate 11 and the second substrate 31 are bonded.

The above manufacturing method of the transducer device is performed by bonding at the wafer level, and while aligning the wafer on which a plurality of first substrates 11 shown in FIG. 3 are formed with the wafer on which a plurality of second substrates 31 are formed, A large number of transducer devices can be obtained by sticking and joining and then dividing into individual pieces.

In the individual transducer device, the ring-shaped joining terminals 17 and 26 are arranged between the acoustic port (opening) 19 and the back chamber (corresponding to the cavity), so that sound leakage does not occur. ..

Next, a second embodiment of the present invention will be described. In the first embodiment described above, the case where the converter 23 and the signal processing circuit 24 are mounted on the first board 11 has been described, but even if the converter 23 and the signal processing circuit 24 are mounted on the second board 31, the converter 23 and the signal processing circuit 24 are mounted on the second board 31. good.

FIG. 5 is a diagram showing the configuration of the transducer device according to the second embodiment of the present invention. The converter 23 and the signal processing circuit 24 are mounted on the second substrate 31. That is, the first point is that the converter 23 and the signal processing circuit 24 are mounted by flip-chip connection on the upper side of the surface having the same height as the concave edge (base end) of the second substrate 31. This is different from the embodiment.

Further, in order to accommodate the conversion unit 23 and the signal processing circuit 24 in the first substrate 11, a recess (concave space) 39 shallower than the depth of the back chamber 35 of the second substrate 31 is formed, and the inner surface of this recess 39 is formed. The point that the shield film 37 is formed is also different from the first embodiment.

The transducer device can be manufactured by joining the first substrate 11 and the second substrate 31 having such a structure with the conductive adhesive 38 and separating them into individual pieces.

In the second embodiment, the external terminal 34 is provided on a surface different from the acoustic port 19, and the top port type is provided as in the first embodiment, but the conversion portion 23 is provided on the side opposite to the back chamber 35. Since the arrangement is made, the space on the side of the back chamber 35 from the conversion unit 23 is widened, and the substantial back chamber is widened, which is advantageous in that the acoustic characteristics can be improved.

Although the embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to the above embodiments. For example, in the first embodiment described above, the case where the through hole via 32 and the external terminal 34 are formed on the second substrate 31 has been described, but the through hole via 32 and the external terminal 34 are formed on the first substrate 11. It may be (Fig. 6). In this case, it is a bottom port type in which the external terminal 34 and the acoustic port 19 are provided on the same surface.

Further, in the second embodiment, the case where the through hole via 32 and the external terminal 34 are formed on the second substrate 31 has been described, but the through hole via 32 and the external terminal 34 are formed on the first substrate 11. Yes (Fig. 7). In this case, it is a bottom port type in which the external terminal 34 and the acoustic port 19 are provided on the same surface.

As described above, according to the present invention, the transducer device includes the sound leakage preventing joint 28 between the conversion unit 23 and the first substrate 11 or the second substrate 31, and thus the conversion unit. It is possible to prevent the sound leakage generated from the gap between 23 and the first substrate 11 or the second substrate 31, and to improve the acoustic characteristics.

Further, as described in the first embodiment, the joint terminal 26 formed on the support 22 of the conversion portion 23 is not electrically connected to the conversion portion 23. Here, FIG. 8 is a diagram for explaining the transducer device of the first embodiment, in which the electrode pads 14 to 16, the bonding terminals 17, the acoustic ports 19 and the wiring 29 formed on the first substrate 11 are arranged. It is schematically shown from the conversion unit 23 and the signal processing circuit side 24, and the joint terminal 17 is not electrically connected to the electrode pad or the like by wiring. Therefore, the sound leakage preventing joint portion 28 formed by connecting the joint terminal 17 and the joint terminal 26 does not electrically affect the electrode pad, the wiring, the converting portion, and the like, and acts only for preventing sound leakage. I understand.

Furthermore, the sound leakage preventing joint portion 28 can be simultaneously formed in the same step as the step of mounting the conversion portion 23 and the signal processing circuit 24 on the first substrate 11 or the second substrate 31 by flip chip connection. Therefore, it can be formed very easily.

The case where the sound leakage prevention joint is formed in a ring shape has been described as an example, but the present invention is not limited to this, and may be formed in, for example, an annular polygon.

11: 1st board|substrate, 12: insulating film, 13: protective film, 14-16: electrode pad, 17: ring-shaped joining terminal, 18: joining terminal, 19 acoustic port (opening), 20: fixed electrode, 21 : Movable electrode, 22: support, 23: conversion part, 24: signal processing circuit, 25: protruding electrode, 26: ring-shaped connecting terminal, 27: protruding electrode, 28: sound leakage preventing connecting part, 29: wiring , 31: second substrate, 32: through-hole via (TSV), 33: insulating film, 34: external terminal, 35: back chamber (cavity), 36: through-hole via terminal, 37: shield film, 38: conductive Adhesive, 39: concave part, 41: substrate, 42: fixed electrode, 43: movable electrode, 44: conversion part, 45: signal processing circuit, 46: bonding wire, 47: acoustic port (opening), 48: lid, 49 : Back chamber, 50: Through hole via (TSV), 51: External terminal

Claims (2)

A first substrate having an opening for connecting the outside and the inside and a second substrate having a cavity are provided, and a conversion unit having a fixed electrode and a movable electrode is arranged between the opening and the cavity, In a transducer device formed by joining the first substrate and the second substrate,
A flip-chip connection unit in which the first substrate and the second substrate are made of silicon, and the conversion unit is mounted on one of the first substrate and the second substrate to form an electrical connection. When, with the opening between the second substrate or between mounting support and the conversion unit of the conversion unit between the first substrate mounted with support and the conversion unit of the conversion unit the the transducer apparatus characterized by comprising a sound leak preventing joint closing the space for communicating the inter-cavity through the flip-chip bonding. The method of manufacturing a transducer apparatus having a converter unit having a fixed electrode and the movable electrode,
A step of forming an opening for connecting the outside and the inside in a unit area forming the transducer device of the first wafer;
Forming a cavity in the unit area of the second wafer;
In one of the unit areas either the first wafer or the second wafer, mounting the conversion unit, the formation Then simultaneously flip chip connection portion for electrically connecting the first wafer or the second forming a sound leakage prevention junction between the second wafer and the support of the conversion unit, the flip-chip the converting part formed by connected the support and the first wafer or the second A step of joining so as to close the gap between the wafer and the wafer,
Bonding the first wafer and the second wafer between the opening and the cavity so as to seal the conversion unit;
A step of cutting the bonded first wafer and second wafer and dividing the bonded first wafer and second wafer into individual transducer devices.

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