CN110743768B

CN110743768B - Ultrasonic probe

Info

Publication number: CN110743768B
Application number: CN201910921889.XA
Authority: CN
Inventors: 蒋富升
Original assignee: Qisda Suzhou Co Ltd; Qisda Corp
Current assignee: Qisda Suzhou Co Ltd; Qisda Corp
Priority date: 2019-09-27
Filing date: 2019-09-27
Publication date: 2021-07-02
Anticipated expiration: 2039-09-27
Also published as: CN110743768A

Abstract

The invention provides an ultrasonic probe, which comprises a substrate of a micro-mechanical ultrasonic transducer and a grounding layer. The substrate of the micro-mechanical ultrasonic transducer is provided with an emitting surface, a sound wave generating array and a grounding wire, wherein the sound wave generating array and the grounding wire are formed on the emitting surface. The ground layer is formed on the edge of the emission surface. The grounding wire is connected with the sound wave generating array and the grounding layer. Thereby improving the effectiveness of the electrical connection.

Description

Ultrasonic probe

Technical Field

The present invention relates to an ultrasonic probe, and more particularly, to an ultrasonic probe having a ground layer.

Background

The ultrasonic probe in the prior art comprises a substrate, an acoustic wave generating array and at least one conducting wire. The sound wave generating array comprises a plurality of sound wave generating units, and each conducting wire is connected with the corresponding connecting sound wave generating array. In order to electrically connect the acoustic wave generating array and the circuit board, bonding wires are generally used to laterally cross the circuit board and the conductive wires to electrically connect the acoustic wave generating array and the circuit board. However, the wire bonding method requires special consideration for the operability of the bonding tool head (e.g., whether the operation space is sufficient), and the wire bonding usually has a length that constitutes a part of the impedance, and the wire bonding is prone to cause the electrical connection to fail, and has low reliability.

Therefore, it is desirable to provide an ultrasonic probe and a method for manufacturing the same that can improve the above-mentioned problems.

Disclosure of Invention

The present invention is directed to an ultrasonic probe capable of improving the effectiveness of electrical connection.

To achieve the above object, the present invention provides an ultrasonic probe, including: the micro-mechanical ultrasonic transducer substrate is provided with an emitting surface, a sound wave generating array and a grounding wire, wherein the sound wave generating array and the grounding wire are formed on the emitting surface; and a ground layer formed on the edge of the emission surface; the grounding wire is connected with the sound wave generating array and the grounding layer.

Preferably, the ground plane is in a closed ring shape.

Preferably, the ground layer includes a ground ring and two ground pads connected to each other, the two ground pads are disposed adjacent to opposite corners of the emission surface, and each of the ground pads has a width greater than that of the ground ring.

Preferably, the acoustic wave generating array includes a plurality of acoustic wave generating units, and the ground layer surrounds the acoustic wave generating units in a closed manner.

Preferably, the ultrasonic probe further comprises:

a conductive adhesive disposed on the emission surface and having a first concave portion;

the circuit board is provided with an opening, the circuit board is arranged on the conductive adhesive, and the opening corresponds to the first concave part to form a second concave part; and

an acoustic wave transmission medium formed in the first recess and the second recess;

the conductive adhesive is positioned between the grounding line of the substrate of the micro-mechanical ultrasonic transducer and the circuit board along the sound wave transmitting direction.

Preferably, the conductive adhesive is anisotropic conductive adhesive.

Preferably, the grounding layer comprises a plurality of grounding portions separated from each other, each grounding portion is adjacent to one side surface of the micro-mechanical ultrasonic transducer substrate, the micro-mechanical ultrasonic transducer substrate comprises a plurality of grounding wires, and each grounding wire is connected with the corresponding grounding portion; the ultrasonic probe further includes:

and the conductive connecting layer is formed on the side surface and is connected with the plurality of grounding parts.

Preferably, the substrate of the micromachined ultrasonic transducer further includes a signal line extending from the acoustic wave generating array to the edge of the emitting surface and spaced from the outer side of the substrate of the micromachined ultrasonic transducer by a distance greater than 10 μm.

Preferably, the acoustic wave generating array includes a resonant cavity, and the substrate of the micromachined ultrasonic transducer further includes:

a plurality of protruding walls protruding from the emission surface and disposed adjacent to the resonant cavity;

wherein, the extending direction of each protruding wall is not parallel to each side of the resonant cavity.

Preferably, the height of each protruding wall is greater than or equal to the depth of the resonant cavity.

Compared with the prior art, the micro-mechanical ultrasonic transducer substrate of the ultrasonic probe is provided with an emitting surface, a sound wave generating array and a grounding wire, wherein the sound wave generating array and the grounding wire are formed on the emitting surface; and a ground layer formed on the edge of the emission surface; the grounding wire is connected with the sound wave generating array and the grounding layer. Therefore, the invention can improve the effectiveness and reliability of the electrical connection and reduce the impedance.

Drawings

FIG. 1A is a schematic top view of an ultrasonic probe according to an embodiment of the invention.

FIG. 1B is a cross-sectional view of the ultrasonic probe of FIG. 1 taken along the direction 1B-1B'.

Fig. 2A is a top view of an ultrasonic probe according to another embodiment of the invention.

FIG. 2B is a cross-sectional view of the ultrasonic probe of FIG. 2A along the direction 2B-2B'.

FIG. 2C is a cross-sectional view of the ultrasonic probe of FIG. 2A along the direction 2C-2C'.

FIG. 3A is a schematic top view of an ultrasonic probe according to another embodiment of the invention.

FIG. 3B is a cross-sectional view of the ultrasonic probe of FIG. 3A along the direction 3B-3B'.

FIG. 4A is a schematic top view of a resonant cavity and a resonant membrane according to another embodiment of the invention.

FIG. 4B is a cross-sectional view of the resonant cavity and the resonant membrane of FIG. 4A along direction 4B-4B'.

Fig. 5a 1-5F illustrate a manufacturing process of the ultrasonic probe of fig. 1A.

Fig. 6a 1-6H illustrate a manufacturing process of the ultrasonic probe of fig. 2A.

Detailed Description

In order to further understand the objects, structures, features and functions of the present invention, the following embodiments are described in detail.

In order to better appreciate the above and other aspects of the present invention, reference will now be made in detail to the embodiments illustrated in the accompanying drawings.

Referring to fig. 1A and 1B, fig. 1A is a top view of an ultrasonic probe 100 according to an embodiment of the invention, and fig. 1B is a cross-sectional view of the ultrasonic probe 100 of fig. 1 along a direction 1B-1B'.

The Ultrasonic probe 100 includes a micro-Machined Ultrasonic Transducer (MUT) substrate 110 (the outer boundary of the micro-machined Ultrasonic Transducer substrate 110 of fig. 1A is drawn by a thick line), a ground layer 120, a conductive adhesive 130, a circuit board 140, an acoustic wave transmission medium 150, a cover plate 155, and a package 160. The substrate 110 of the micromachined ultrasonic transducer has an emitting surface 110u, an acoustic wave generating array 111, at least one ground line 110g and at least one signal line 110 s. The acoustic wave generating array 111, the ground line 110g, and the signal line 110s are formed on the emitting surface 110 u. The ground layer 120 is formed at the edge of the emission surface 110 u. The ground line 110g connects the acoustic wave generating array 111 and the ground layer 120. Thus, all the grounding lines 110g extend to the grounding layer 120 and are electrically connected to a grounding potential (not shown) of the circuit board 140 through the grounding layer 120. Thus, the ground wire 110g can be electrically connected to the circuit board 140 without bonding wires.

In addition, the "edge" is, for example, a region outside the acoustic wave generating array 111, and the range thereof may extend to the outer side 110e of the substrate 110 of the micromachined ultrasonic transducer, but the embodiment of the invention is not limited thereto.

As shown in fig. 1A and 1B, the acoustic wave generating array 111 includes at least one acoustic wave generating unit 1111. Each sound wave generating unit 1111 includes at least one resonant cavity 1111r and at least one resonant diaphragm 1112. Each of the resonator films 1112 is formed on the emission surface 110u and covers the corresponding resonator 1111 r. Each of the sound wave generating units 1111 further includes at least one signal connection 1111s and at least one ground connection 1111 g. Each of the resonance membranes 1112 is connected to the signal line 110s by a corresponding one of the signal connection lines 1111s, and each of the resonance membranes 1112 is connected to the ground line 110g by a corresponding one of the ground connection lines 1111 g. Each signal line 110s connects the corresponding sound wave generating unit 1111 to the edge of the emitting surface 110u, and each ground line 110g connects the corresponding sound wave generating unit 1111 to the ground layer 120. For the control of one sound wave generating unit 1111, a control signal C1 of the controller 10 can be transmitted to the signal line 110s through the circuit board 140, and then returned to the controller 10 through the ground line 110g and the circuit board 140 after passing through the signal connection line 1111s and the ground connection line 1111g connected to each resonator film 1112. The control signal C1 can control all the resonant membranes 1112 of each sound wave generating unit 1111 to oscillate up and down to emit ultrasonic waves. Furthermore, depending on the focusing characteristics of the sound wave, different sound wave generating units 1111 can be controlled by different control signals C1, such as control signals C1 with different delay times, so that all sound wave generating units 1111 are focused on the same region as a point.

In addition, the resonant cavity 1111r, the resonant diaphragm 1112, the signal connection 1111s, and the ground connection 1111g may be formed by a semiconductor process, such as photolithography, coating, and/or any other semiconductor technique that can form the acoustic wave generating array 111.

As shown in fig. 1A, the ground plane 120 has a closed ring shape. The ground layer 120 closely surrounds the entire acoustic wave generating unit 1111. The substrate 110 has an outer side surface 110 e. In the present embodiment, the ground layer 120 abuts the outer side surface 110e of the substrate 110. In another embodiment, the ground layer 120 may be adjacent to the outer side 110e of the substrate 110, but spaced apart from the outer side 110e by a distance. In other embodiments, a portion of the ground layer 120 may extend to the outer side 110e of the substrate 110, and another portion of the ground layer 120 may be adjacent to the outer side 110e of the substrate 110 but spaced apart from the outer side 110e by a distance.

As shown in fig. 1A, the ground layer 120 includes a ground ring 120g1 and two ground pads 120g2 connected together. Two ground pads 120g2 are disposed adjacent to a pair of corners of the emitting surface 110u, and the width W1 of each ground pad 120g2 is greater than the width W2 of the ground ring 120g 1. Since the ground pad 120g2 of the ground layer 120 provides a sufficient width, the overlapping area of the ground pad (not shown) of the circuit board 140 and the ground pad 120g2 of the ground layer 120 can be increased, thereby improving the quality of the electrical connection.

As shown in fig. 1B, the entire ground layer 120 is electrically connected to the ground potential of the circuit board 140 through the ground pad 120g2 (the ground pad 120g2 is shown in fig. 1A), the conductive adhesive 130 and the ground pad (not shown) of the circuit board 140. In the embodiment of the invention, the circuit board 140 and the ground layer 120 are electrically connected through the conductive adhesive 130, and compared with the conventional bonding wire, the conductive adhesive has higher reliability, shorter electrical transmission path and lower impedance.

As shown in fig. 1B, the conductive paste 130 is disposed on the emitting surface 110 u. For example, the conductive adhesive 130 is located between the ground line 110g of the micromachined ultrasonic transducer substrate 110 and the ground pad 140g of the circuit board 140, and between the signal line 110s of the micromachined ultrasonic transducer substrate 110 and the signal pad 140s of the circuit board 140 along the acoustic wave emitting direction E1. The conductive paste 130 allows electrical transmission in the Z-axis (e.g., the Z-axis is substantially parallel to the acoustic emission direction E1) but does not allow electrical transmission in the X-and Y-axes (e.g., substantially perpendicular to the Z-axis). Therefore, even if the conductive adhesive 130 is a continuous conductive adhesive, the two adjacent signal lines 110s are not electrically shorted by the conductive adhesive 130 and the two adjacent ground lines 110g are not electrically shorted by the conductive adhesive 130. In the present embodiment, the Conductive paste 130 is Anisotropic Conductive Film (ACF) or other Conductive material that allows Z-axis electrical transmission only. One of the illustrated X-axis and Y-axis is, for example, a long axis transmission direction of the ultrasonic probe 100, and the other of the X-axis and Y-axis is, for example, a short axis transmission direction of the ultrasonic probe 100.

As shown in fig. 1B, the conductive paste 130 has a first concave portion 130 r. The Circuit board 140 is, for example, a Flexible Printed Circuit (FPC), but the embodiment of the invention is not limited thereto. The circuit board 140 has an opening 140a, the circuit board 140 is disposed on the conductive adhesive 130, and the opening 140a forms a second recess 140r corresponding to the first recess 130 r. The acoustic wave transmission medium 150 is formed in the first recess 130r and the second recess 140r, and fills the first recess 130r and the second recess 140r, for example. The acoustic wave transmission medium 150 is, for example, silicone oil, glycerin, or other non-conductive and acoustic wave transmissive medium. The acoustic transmission medium 150 can help transmit the ultrasonic waves generated by the acoustic wave generating array 111. As shown in fig. 1A, the conductive adhesive 130 has a closed ring shape, such that the first concave portion 130r is not communicated with the outer side surface of the conductive adhesive 130, and the circuit board 140 has a closed ring shape, such that the second concave portion 140r is not communicated with the outer side surface of the circuit board 140. Thus, the acoustic wave transmission medium 150 located in the first recess 130r and the second recess 140r does not leak laterally from the conductive paste 130 and the circuit board 140.

In addition, the second recess 140r substantially overlaps, such as at least partially overlaps, the first recess 130 r. In one embodiment, the second recess 140r may be smaller than or substantially equal to the size (e.g., top area) of the first recess 130r, but the second recess 140r is also larger than the size (e.g., top area) of the first recess 130 r.

The cover plate 155 is disposed on the circuit board 140 and covers the opening 140a to cover the first recess 130r and the second recess 140r, so as to prevent the acoustic wave transmission medium 150 located in the first recess 130r and the second recess 140r from leaking out of the opening 140 a. In addition, although not shown, the ultrasonic probe 100 further includes an adhesive layer formed between the cover plate 155 and the circuit board 140 to fix the relative position of the cover plate 155 and the circuit board 140. In summary, the acoustic wave transmission medium 150 is enclosed in the first recess 130r and the second recess 140r by the conductive adhesive 130, the circuit board 140 and the cover 155. In addition, the cover plate 155 allows sound waves to pass out, having a sound wave transmission rate of, for example, 80%, 85%, 90%, or 95% or more. In one embodiment, the cover plate 155 may be a light transmissive or non-light transmissive cover plate. In terms of material, the material of the cover plate 155 includes resin, such as polyurethane.

As shown in fig. 1B, the package 160 encapsulates the substrate 110 of the micromachined ultrasonic transducer, the ground layer 120, the conductive adhesive 130, a portion of the circuit board 140, and the cover plate 150. The other portion of the circuit board 140 protrudes from the package 160 to be electrically connected to the controller 10. The material of the encapsulant 160 includes phenolic-based resin (Novolac-based resin), epoxy-based resin (epoxy-based resin), silicone-based resin (silicone-based resin), or other suitable coating agent. The package body 160 may also include a suitable filler, such as powdered silicon dioxide. In addition, the package body 160 may be formed by using several packaging techniques, such as compression molding (compression molding), liquid encapsulation (liquid encapsulation), injection molding (injection molding) or transfer molding (transfer molding).

Referring to fig. 2A to 2C, fig. 2A is a top view of an ultrasonic probe 200 according to another embodiment of the invention, fig. 2B is a cross-sectional view of the ultrasonic probe 200 of fig. 2A along a direction 2B-2B ', and fig. 2C is a cross-sectional view of the ultrasonic probe 200 of fig. 2A along a direction 2C-2C'.

The ultrasonic probe 200 includes a micromachined ultrasonic transducer substrate 210 (the outer boundary of the micromachined ultrasonic transducer substrate 210 of fig. 2A is drawn with a thick line), a ground layer 220, a conductive adhesive 230, a circuit board 140, an acoustic wave transmission medium 150, a cover plate 155, a package 160, and a conductive connection layer 270. The substrate 210 of the micromachined ultrasonic transducer has an emitting surface 110u, an acoustic wave generating array 111, at least one ground line 110g, at least one signal line 110s, and at least one retaining wall 212. The acoustic wave generating array 111, the grounding line 110g, the signal line 110s and the dam 212 are formed on the emitting surface 110 u. The ground layer 120 is formed on the edge of the emitting surface 110u, wherein the ground line 110g connects the acoustic wave generating array 111 and the ground layer 120.

In the embodiment, the ground layer 220 is adjacent to the outer side surface 210e of the substrate 210 of the micromachined ultrasonic transducer, but the embodiment of the invention is not limited thereto. The ground plane 220 includes a ground ring 221 and two ground pads 120g2 connected together. Two ground pads 120g2 are disposed adjacent to a pair of corners of the emitting surface 110 u. The width W1 of each ground pad 120g2 is greater than the width W2 of the ground ring 221. Since the ground pad 120g2 of the ground layer 120 provides a sufficient width, the overlapping area of the ground pad (not shown) of the circuit board 140 and the ground pad 120g2 of the ground layer 220 can be increased, thereby improving the quality of the electrical connection.

As shown in fig. 2A, the ground ring 221 of the ground layer 220 includes a plurality of ground portions 221g separated from each other, and each ground portion 221g is adjacent to the outer side surface 210e of the micromachined ultrasonic transducer substrate 110, for example, extends to the outer side surface 210 e. Each ground line 110g of the micromachined ultrasonic transducer substrate 110 is connected to a corresponding ground portion 221 g. The conductive connection layer 270 is formed on the outer side surface 210e of the substrate 110 of the micromachined ultrasonic transducer and connected to the plurality of grounding portions 221g, so that the plurality of grounding portions 221g separated from each other are electrically connected through the conductive connection layer 270.

As shown in fig. 2B, the entire ground layer 220 is electrically connected to the ground potential of the circuit board 140 through the ground pad 120g2, the conductive adhesive 230 and the ground pad (not shown) of the circuit board 140. As shown in fig. 2A, the conductive adhesive 230 includes a plurality of separated conductive adhesive pads 231. Each conductive rubber pad 231 covers the corresponding ground line 110g or the corresponding signal line 110 s. The conductive rubber pads 231 and the grounding portions 221g of the grounding layer 220 are spaced from each other to prevent the signal line 110s from being electrically shorted to the grounding portions 221g through the conductive rubber pads 231. In the present embodiment, the conductive paste 230 has non-directional electrical transmission, i.e., allows electrical transmission along the Z-axis, the X-axis and the Y-axis. Since the conductive pads 231 are separated from each other, even if the electrical transmission of the conductive adhesive 230 is non-directional, the adjacent two conductive pads 231 will not be electrically shorted. In one embodiment, the conductive paste 230 is silver paste, but may be other conductive materials. In addition, as shown in fig. 2A and 2B, the signal line 110s extends from the acoustic wave generating array 111 to the edge of the emitting surface 110u and is away from the outer side surface 210e of the substrate 110 of the micromachined ultrasonic transducer by a distance H1, and the distance H1 can prevent the conductive connecting layer 270 from contacting the signal line 110 s. In one embodiment, distance H1 is, for example, greater than 10 microns, such as between 150 microns and 250 microns. The above-mentioned value range is sufficient to prevent the conductive connection layer 270 from contacting the signal line 110 s.

As shown in fig. 2A to 2C, the plurality of conductive adhesive pads 231 of the conductive adhesive 230 are distributed on two opposite edges of the emitting surface 110u (not shown in fig. 2A) of the substrate 110 of the micromachined ultrasonic transducer, and the two blocking walls 212 are respectively located on the other two opposite edges of the emitting surface 110u, wherein the plurality of conductive adhesive pads 231 and the two blocking walls 212 surround the first concave portion 230r, and the first concave portion 230r exposes the acoustic wave generating array 111. The circuit board 140 has a second recess 140 r. The acoustic wave transmission medium 150 is located in the first recess 230r and the second recess 140 r. Due to the configuration of the retaining wall 212, the acoustic wave transmission medium 150 in the first recess 230r and the second recess 140r can be blocked from leaking. In addition, since the plurality of separated conductive rubber pads 231 are disposed adjacently (but not in contact), a certain leakage resistance is generated for the acoustic wave transmission medium 150 located in the first concave portion 230r and the second concave portion 140r, which can reduce the leakage amount or even eliminate the leakage. In addition, in an embodiment, the retaining wall 212 and the plate body of the micromachined ultrasonic transducer substrate 110 may be an integrated structure. In addition, the dam 212 is, for example, an insulating dam, so that the signal line 110s can be prevented from being electrically shorted with the ground layer 220 through the conductive adhesive 230 and the dam 212.

Referring to fig. 3A to 3B, fig. 3A is a top view of an ultrasonic probe 300 according to another embodiment of the invention, and fig. 3B is a cross-sectional view of the ultrasonic probe 300 of fig. 3A along a direction 3B-3B'.

The ultrasonic probe 300 includes a micromachined ultrasonic transducer substrate 210, a ground layer 220, a conductive adhesive 230, a circuit board 140, an acoustic wave transmission medium 150, a cover plate 155, a package 160, and a conductive connection layer 270. The substrate 210 of the micromachined ultrasonic transducer has an emitting surface 110u, an acoustic wave generating array 111, at least one ground line 110g, at least one signal line 110s, and at least one retaining wall 212. The acoustic wave generating array 111, the ground line 110g, the signal line 110s, and the dam 212 are formed on the emitting surface 110 u. The ground layer 120 is formed on the edge of the emitting surface 110u, wherein the ground line 110g connects the acoustic wave generating array 111 and the ground layer 120.

The ultrasonic probe 300 of the embodiment of the invention has the same or similar technical features as the ultrasonic probe 200, except that a gap H2 is formed between the grounding parts 221g and the outer side surface 210e of the micromachined ultrasonic transducer substrate 210, and the conductive connection layer 270 extends into the gap H2, i.e., extends above the emitting surface 110 u. In addition, the conductive connecting layer 270 connects the grounding portions 221g, so that the separated grounding portions 221g are electrically connected through the conductive connecting layer 270.

Referring to fig. 4A-4B, fig. 4A is a top view of a resonant cavity 1111r and a resonant membrane 1112 according to another embodiment of the invention, and fig. 4B is a cross-sectional view of the resonant cavity 1111r and the resonant membrane 1112 of fig. 4A along a direction 4B-4B'. The micromachined

ultrasonic transducer substrate

110 or 210 of any one of the ultrasonic probes 100-300 may further include a plurality of protruding walls 113. The protruding wall 113 protrudes from the emitting surface 110u and is disposed adjacent to the resonant cavity 1111 r. The plurality of protruding walls 113 surround the corresponding resonant cavity 1111r, wherein each protruding wall 113 extends in a direction not parallel to each side of the resonant cavity 1111 r. In addition, the included angle a1 between two adjacent protruding walls 113 is, for example, between 70 degrees and 100 degrees. In one embodiment, the height L1 of each protruding wall 113 is greater than or equal to the depth L2 of the resonant cavity 1111 r. The protruded wall 113 can increase the strength of the substrate of the micromachined ultrasonic transducer, and reduce the deformation of the resonant cavity 1111r and the resonant membrane 1112. Thus, when the ultrasonic probe is pressed against an object to be measured (e.g., a human body), the protruding wall 113 can reduce the deformation of the resonant cavity 1111r and the resonant membrane 1112 when pressed, thereby ensuring that the generated ultrasonic wave meets the expected characteristics. In addition, the protruding wall 113 and the plate of the substrate of the micromachined ultrasonic transducer are formed as an integral structure, but the embodiment of the invention is not limited thereto.

Referring to fig. 5a 1-5F, a process of manufacturing the ultrasonic probe 100 of fig. 1A is shown.

As shown in fig. 5a1 and fig. 5a2, a substrate 110 of a micromachined ultrasonic transducer is provided, wherein the substrate 110 of the micromachined ultrasonic transducer includes a transmitting surface 110u, an acoustic wave generating array 111, at least one ground line 110g and at least one signal line 110 s. The acoustic wave generating array 111 includes at least one acoustic wave generating unit 1111, wherein a ground line 110g and a signal line 110s extend from the corresponding acoustic wave generating unit 1111 to the edge of the emitting surface 110 u. In addition, the ground layer 120 is formed on the emitting surface 110u of the substrate 110 of the micromachined ultrasonic transducer, for example, on the edge of the emitting surface 110u, wherein the ground line 110g connects the acoustic wave generating array 111 and the ground layer 120.

As shown in fig. 5B1 and 5B2, the conductive paste 130 may be formed to cover at least a portion of the ground layer 120, a portion of the ground line 110g, and a portion of the signal line 110s by, for example, a coating technique. The conductive adhesive 130 has a first recess 130r, and the first recess 130r exposes the acoustic wave generating array 111, for example, exposes all of the acoustic wave generating units 1111.

As shown in fig. 5C, the circuit board 140 is disposed on the conductive adhesive 130, wherein the circuit board 140 has a second concave portion 140r, and the second concave portion 140r exposes the acoustic wave generating array 111 and the first concave portion 130 r. The second recess 140r substantially overlaps, such as at least partially overlaps, the first recess 130 r.

As shown in fig. 5D, the acoustic transmission medium 150 can be formed in the first recess 130r and the second recess 140r by, for example, an injection technique. The acoustic wave transmission medium 150 fills at least a part of the first recess 130r and the second recess 140 r.

As shown in fig. 5E, the cover plate 155 is disposed to cover the opening 140a of the second recess 140 r. Although not shown, an adhesive layer may be formed between the cover plate 155 and the circuit board 140 to fix the relative position between the acoustic cover plate 155 and the circuit board 140.

As shown in fig. 5F, the package 160 can be formed by compression molding, liquid encapsulation, injection molding or transfer molding, for example, to encapsulate the micro-mechanical ultrasonic transducer substrate 110, the ground layer 220, the conductive adhesive 130, a portion of the circuit board 140 and the cover plate 155, so as to form the ultrasonic probe 100. Another portion of the circuit board 140 protrudes from the package 160 to be electrically connected to the controller 10 (the controller 10 is shown in fig. 1B).

Referring to fig. 6a 1-6H, a process of manufacturing the ultrasonic probe 200 of fig. 2A is shown.

As shown in fig. 6a1 and fig. 6a2, a substrate 210 of a micromachined ultrasonic transducer is provided, wherein the substrate has a radiation surface 110u, an acoustic wave generating array 111, at least one ground line 110g, at least one signal line 110s, and at least one retaining wall 212. The acoustic wave generating array 111 includes at least one acoustic wave generating unit 1111, wherein a ground line 110g and a signal line 110s extend from the corresponding acoustic wave generating unit 1111 to the edge of the emitting surface 110 u. The retaining wall 212 protrudes from the emitting surface 110u and is, for example, an integrally formed structure with the plate body of the micromachined ultrasonic transducer substrate 210, but the embodiment of the invention is not limited thereto.

In addition, the ground layer 220 is formed on the emitting surface 110u of the substrate 210 of the micromachined ultrasonic transducer, for example, on the edge of the emitting surface 110u, wherein the ground line 110g connects the acoustic wave generating array 111 and the ground layer 220. The ground plane 220 includes a ground ring 221 and two ground pads 120g2 connected together. Two ground pads 120g2 are disposed adjacent to a pair of corners of the emitting surface 110 u.

As shown in fig. 6B, a conductive adhesive 230 may be formed by a coating technique to cover at least a portion of the ground layer 220, a portion of the ground line 110g, and a portion of the signal line 110 s. In this step, as shown, the conductive adhesive 230 includes two

adhesive strips

230A and 230B extending continuously, and the

adhesive strips

230A and 230B are respectively located at two opposite edges of the emitting surface 110 u. Each of the

adhesive tapes

230A and 230B covers the signal line 110s and the ground line 110g on the same side edge. The two retaining walls 212 are respectively located at the other two opposite edges of the emitting surface 110u, wherein the conductive adhesive 230 and the retaining walls 212 surround the first recess 230r, and the first recess 230r exposes the acoustic wave generating array 111. In the present embodiment, the electrical transmission of the conductive paste 230 is non-directional, i.e., allows electrical transmission along the Z-axis, the X-axis and the Y-axis.

As shown in fig. 6C, the conductive adhesive 230 may be cut into a plurality of separated conductive adhesive pads 231 and the ground ring 221 is cut into a plurality of separated ground portions 221g by using, for example, a cutting technique, wherein each ground line 110g is covered by the corresponding conductive adhesive pad 231 and each signal line 110s is covered by the corresponding conductive adhesive pad 231. Since the conductive pads 231 are separated from each other, even if the electrical transmission of the conductive adhesive 230 is non-directional, the adjacent two conductive pads 231 will not be electrically shorted. In addition, the cutting process is performed by using a cutter or a laser.

As shown in fig. 6D, the circuit board 140 is disposed on the plurality of conductive pads 231, wherein the circuit board 140 has a second concave portion 140r, and the second concave portion 140r exposes the acoustic wave generating array 111 and the first concave portion 130 r. The second recess 140r substantially overlaps, such as at least partially overlaps, the first recess 230 r.

As shown in fig. 6E, the acoustic transmission medium 150 can be formed in the first recess 230r and the second recess 140r by injection molding. The acoustic wave transmission medium 150 fills at least a part of the first concave portion 230r and the second concave portion 140 r.

As shown in fig. 6F, the cover plate 155 is disposed to cover the opening 140a of the second recess 140 r. Although not shown, an adhesive layer may be formed between the cover plate 155 and the circuit board 140 to fix the relative position between the acoustic cover plate 155 and the circuit board 140.

As shown in fig. 6G, the circuit board 140 is folded back to expose the outer surface 210e and the grounding portion 221G of the substrate 210 of the micromachined ultrasonic transducer.

As shown in fig. 6H, a conductive connection layer 270 may be formed on the outer side 210e by, for example, a coating technique. By the capillary phenomenon, the conductive connection layer 270 in a fluid state penetrates into a gap between the ground portion 221g and the circuit board 140, and connects all the ground portions 221g exposed from the outer side surface 210 e. The conductive connection layer 270 may then be heated to cure the conductive connection layer 270.

Then, the package 160 is formed to cover the micro-mechanical ultrasonic transducer substrate 210, the ground layer 220, the conductive adhesive 230, a portion of the circuit board 140, and the cover plate 155 of fig. 6H by compression molding, liquid encapsulation, injection molding, or transfer molding, for example, to form the ultrasonic probe 200. Another portion of the circuit board 140 protrudes from the package 160 to be electrically connected to the controller 10 (the controller 10 is shown in fig. 1B).

The manufacturing method of the ultrasonic probe 300 is similar to or the same as the ultrasonic probe 200, and is not described herein again.

The present invention has been described in relation to the above embodiments, which are only exemplary of the implementation of the present invention. It should be noted that the disclosed embodiments do not limit the scope of the invention. Rather, it is intended that all such modifications and variations be included within the spirit and scope of this invention.

Claims

1. An ultrasonic probe, comprising:

the micro-mechanical ultrasonic transducer substrate is provided with an emitting surface, a sound wave generating array and a grounding wire, wherein the sound wave generating array and the grounding wire are formed on the emitting surface; and

a ground layer formed on the edge of the emission surface;

the grounding wire is connected with the sound wave generating array and the grounding layer.

2. The ultrasonic probe of claim 1, wherein the ground plane is in the shape of a closed loop.

3. The ultrasonic probe of claim 1, wherein the grounding layer comprises a grounding ring and two grounding pads connected to each other, the two grounding pads being disposed adjacent to opposite corners of the emitting surface, each of the grounding pads having a width greater than a width of the grounding ring.

4. The ultrasonic probe of claim 1, wherein the acoustic wave generating array comprises a plurality of acoustic wave generating units, and the ground plane hermetically surrounds the plurality of acoustic wave generating units.

5. The ultrasonic probe of claim 1, further comprising:

6. The ultrasonic probe of claim 5, wherein the conductive adhesive is anisotropic conductive adhesive.

7. The ultrasonic probe of claim 1, wherein the grounding layer comprises a plurality of grounding portions separated from each other, each grounding portion being adjacent to a side surface of the micromachined ultrasonic transducer substrate, the micromachined ultrasonic transducer substrate comprising a plurality of grounding lines, each grounding line being connected to a corresponding grounding portion; the ultrasonic probe further includes:

8. The ultrasonic probe of claim 7, wherein the micromachined ultrasonic transducer substrate further comprises a signal line extending from the acoustic wave generating array in a direction toward the edge of the emitting surface and spaced from an outer side surface of the micromachined ultrasonic transducer substrate by a distance greater than 10 μm.

9. The ultrasonic probe of claim 1, wherein the acoustic wave generating array comprises a resonant cavity, the micromachined ultrasonic transducer substrate further comprising:

10. The ultrasonic probe of claim 9, wherein the height of each protruding wall is greater than or equal to the depth of the resonant cavity.