Two-dimensional area array ultrasonic transducer based on FCBGA

Abstract

The utility model provides a two-dimensional area array ultrasonic transducer based on FCBGA, comprising a device layer, the device layer comprises a plurality of piezoelectric units arranged in an array, and a positive electrode layer and a negative electrode layer plated on two sides of the piezoelectric units, the positive electrode layer or the negative electrode layer is provided with a conductive column; the circuit board is provided with a first surface, a second surface and a through hole penetrating through the first surface and the second surface; the first surface is provided with a welding spot, a first circuit and a first electrode, the first circuit is used for connecting the welding spot and the first electrode, the first electrode is arranged at the edge of the circuit board, the second surface is provided with a second circuit and a second electrode, the second circuit is used for connecting the second electrode and the through hole, and the second electrode is arranged at the edge of the circuit board; the first surface faces the device layer, and the welding spots and the through holes are combined to exactly correspond to all the conductive columns. According to the two-dimensional area array ultrasonic transducer based on the FCBGA, crosstalk between array elements (piezoelectric units) can be avoided.

Description

Technical Field

[0001] The utility model relates to the medical field, in particular to a two-dimensional array ultrasonic transducer based on FCBGA. Background Art

[0002] In the field of medical ultrasound, miniaturized two-dimensional ultrasound transducer arrays can be used for intracavitary (intravascular ultrasound (IVUS), intracardiac ultrasound (ICE)) 4D imaging; the technical difficulties in making two-dimensional ultrasound transducer arrays mainly include electrode leads, bonding technology, acoustic matching technology, material surface treatment process, etc.; among them, electrode leads are the bottleneck in the technology of making miniaturized two-dimensional ultrasound transducer arrays; the current technology is mainly based on bonding wires under a microscope, gold wire bonding (WireBonding), and using FPC to bond electrode wires by pressurized heating and curing, but this method is currently mainly used in One-dimensional ultrasonic transducer arrays are being manufactured; for miniaturized two-dimensional ultrasonic transducer arrays, the transducer center frequency is in the range of 6MHz-9MHz, and the array element spacing (~λ) is theoretically no more than 0.257mm, and in practical applications it generally does not exceed 0.384mm (~1.5λ); for linearly arranged phased arrays, the array element spacing (~0.5λ) is theoretically no more than 0.1285mm, and in practical applications it generally does not exceed 0.257mm (~λ); at this size, using current electrode bonding technology, the leads will become very complicated and produce significant parasitic reactance and crosstalk between array elements. Summary of the invention

[0003] In view of the deficiencies in the prior art, the utility model provides a two-dimensional area array ultrasonic transducer based on FCBGA to realize an ultrasonic transducer without parasitic reactance and array element crosstalk.

[0004] To this end, an embodiment provides a two-dimensional area array ultrasonic transducer based on FCBGA, including:

[0005] A device layer, the device layer comprising a plurality of piezoelectric units arranged in an array and a positive electrode layer and a negative electrode layer plated on both sides of the piezoelectric units, wherein a conductive column is provided on the positive electrode layer or the negative electrode layer;

[0006] A circuit board, the circuit board having a first surface, a second surface, and a through hole penetrating the first surface and the second surface; a solder joint, a first circuit, and a first electrode are arranged on the first surface, the first circuit is used to connect the solder joint and the first electrode, and the electrode is arranged at an edge of the circuit board; a second circuit and a second electrode are arranged on the second surface, the second circuit is used to connect the second electrode and the through hole, and the second electrode is arranged at an edge of the circuit board;

[0007] The first surface faces the device layer, and the solder joints and the through holes in combination just correspond to all the conductive pillars.

[0008] As a further optional solution of the FCBGA-based two-dimensional area array ultrasonic transducer, the through hole is filled with conductive glue.

[0009] As a further optional solution of the FCBGA-based two-dimensional area array ultrasonic transducer, a conductive ring is provided around the through hole on the second surface.

[0010] As a further optional solution of the FCBGA-based two-dimensional area array ultrasonic transducer, the through holes and the solder joints are arranged alternately in rows or columns.

[0011] As a further optional solution of the FCBGA-based two-dimensional array ultrasonic transducer, the gap between the device layer and the circuit board is filled with insulating glue.

[0012] As a further optional solution of the FCBGA-based two-dimensional area array ultrasonic transducer, the conductive pillar is made of metal material.

[0013] As a further optional solution of the FCBGA-based two-dimensional array ultrasonic transducer, the device layer further includes silicon-on-insulator, and the silicon-on-insulator is connected to the piezoelectric unit facing away from the conductive pillar.

[0014] As a further optional solution of the FCBGA-based two-dimensional array ultrasonic transducer, the silicon-on-insulator and the piezoelectric unit are fixed by a hot pressing process.

[0015] As a further optional solution of the FCBGA-based two-dimensional area array ultrasonic transducer, the solder joints and the conductive pillars can be soldered together by a reflow soldering method.

[0016] As a further optional solution of the FCBGA-based two-dimensional area array ultrasonic transducer, the conductive pillar is metal tin.

[0017] Implementing the embodiments of the present utility model will have the following beneficial effects:

[0018] According to the two-dimensional array ultrasonic transducer based on FCBGA in the above embodiment, the device layer is an ultrasonic module, and the existence of the circuit board is convenient for connecting electricity to energize the piezoelectric unit. After the piezoelectric unit is energized, it will vibrate, thereby driving the propagation medium to generate ultrasonic waves. Since the circuit board has a first surface and a second surface, the solder joints on the first surface correspond to half of the conductive columns, and the other half of the conductive columns are electrically connected to the second circuit on the second surface after passing through the through holes. The first electrode of the first surface is located at the edge of the first surface, and the electrode of the second surface is located at the edge of the second surface, so as to facilitate soldering and electricity connection. The two-dimensional array ultrasonic transducer based on FCBGA in the utility model cleverly divides the dense electrode connection points at the edges of both sides of the circuit board, and there are no leads, which greatly reduces the generation of parasitic reactance, thereby avoiding crosstalk with the array element (piezoelectric unit). BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] in: Figure 1 A schematic cross-sectional structure diagram of a two-dimensional area array ultrasonic transducer based on FCBGA provided according to an embodiment of the utility model is shown; Figure 2 A schematic diagram of a structure in which a conductive column on a device layer is a solder ball provided in an embodiment of the utility model is shown; Figure 3 A schematic diagram of a structure in which another conductive pillar on a device layer is a copper pillar provided in an embodiment of the utility model is shown; Figure 4 A schematic plan view of a device layer provided according to an embodiment of the utility model is shown; Figure 5 A schematic structural diagram of a first surface of a circuit board provided according to an embodiment of the utility model is shown; Figure 6 A schematic structural diagram of a second surface of a circuit board provided according to an embodiment of the utility model is shown; Figure 7 A physical diagram of a first surface of a circuit board provided according to an embodiment of the utility model is shown; Figure 8 A physical diagram of the second side of a circuit board provided according to an embodiment of the utility model is shown.

[0021] Explanation of the main component symbols: device layer-10; piezoelectric unit-110; conductive column-120; circuit board-20; first surface-210; second surface-220; through hole-230; solder joint-2110; first line-2120; first electrode-2130; second line-2210; second electrode-2220; conductive ring-2310; silicon on insulator-30. Implementation

[0022] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively with reference to the accompanying drawings. The accompanying drawings provide preferred embodiments of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0023] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the technical field of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0025] In the embodiment of the present utility model, a two-dimensional array ultrasonic transducer based on FCBGA is provided, please refer to Figure 1-Figure 8The FCBGA-based two-dimensional array ultrasonic transducer comprises: a device layer 10, wherein the device layer 10 comprises a plurality of piezoelectric units 110 arranged in an array and a positive electrode layer and a negative electrode layer plated on both sides of the piezoelectric unit 110, wherein the piezoelectric unit 120 is arranged on the positive electrode layer or the negative electrode layer; a circuit board 20, wherein the circuit board 20 has a first surface 210, a second surface 220, and a through hole 230 penetrating the first surface 210 and the second surface 220; a solder joint 2110, a first line 2120, and a first line 2130 are arranged on the first surface 210, wherein the first line 2120 is used to connect the solder joint 2110 and the first circuit 2130, and the first circuit 2130 is arranged at the edge of the circuit board 20; the second surface 220 is provided with a second circuit 2210 and a second electrode 2220, and the second circuit 2210 is used to connect the second electrode 2220 and the through hole 230, and the second electrode 2220 is arranged at the edge of the circuit board 20; the first surface 210 faces the device layer 10, and the solder joint 2110 and the through hole 230 are combined to correspond to all the piezoelectric units 120.

[0026] According to the two-dimensional array ultrasonic transducer based on FCBGA in the above embodiment, the device layer 10 is an ultrasonic module, and the circuit board 20 exists to facilitate the connection of electricity to energize the piezoelectric unit 110. After the piezoelectric unit 110 is energized, it will vibrate, thereby driving the propagation medium to generate ultrasonic waves. Since the circuit board 20 has a first surface 210 and a second surface 220, the solder joints 2110 on the first surface 210 correspond to half of the piezoelectric unit 120, and the other half of the piezoelectric unit 120 passes through the through hole 230 and is electrically connected to the second circuit on the second surface 220. The first circuit 2130 of the first surface 210 is located at the edge of the first surface 210, and the electrode of the second surface 220 is located at the edge of the second surface 220, so as to facilitate soldering and electricity connection. The two-dimensional array ultrasonic transducer based on FCBGA in the utility model cleverly divides the dense electrode connection points at the edges of both sides of the circuit board 20, and there are no leads, which greatly reduces the generation of parasitic reactance, thereby avoiding crosstalk with the array element (piezoelectric unit 110).

[0027] The FC-BGA packaging technology originated in the 1960s, when IBM developed the so-called C4 (Controlled Collapse Chip Connection) technology for the assembly of large computers. It was later further developed into a technology that can use the surface tension of molten bumps to support the weight of the chip and control the height of the bumps, and became the development direction of flip-chip technology.

[0028] It solves the electromagnetic compatibility (EMC) and electromagnetic interference (EMI) problems. Generally speaking, the signal transmission of the chip using WireBond packaging technology is carried out through a metal wire with a certain length. This method will produce the so-called impedance effect under high frequency conditions, forming an obstacle on the signal path. The current in the utility model is to change periodically at high frequency, so that the piezoelectric unit 110 vibrates periodically to generate ultrasonic waves.

[0029] Another obvious advantage of FCBGA is that the number of probe arrays can be expanded. It is not only suitable for the development of one-dimensional arrays, but also can be expanded to two-dimensional array transducers. The expanded transducers can be effectively interconnected and conducted. In addition, another obvious advantage of FCBGA is that the sensor can simulate the front-end circuit inside the sensor. That is to say, after the ASIC circuit is attached to the back of the sensor, the signal is directly transmitted to the circuit through the copper pillars and solder balls of FCBGA, which reduces the path loss and the loss caused by matching. FCBGA packaging facilitates integrated manufacturing. Semiconductor processes are usually matched between the leading process and the back-end process, because sensor chip production lines are all integrated manufacturing. This also avoids the impact of the intermediate single-step process on the production and sensor quality.

[0030] The electrode materials of the positive electrode layer and the negative electrode layer are generally copper or conductive materials such as gold / silver / nickel.

[0031] In some specific embodiments, the through hole 230 is filled with conductive glue.

[0032] The height of the piezoelectric unit 120 is sometimes not enough, so a conductive glue is needed. The conductive glue can ensure that the second circuit and the piezoelectric unit 120 are electrically connected.

[0033] In some specific embodiments, on the second surface 220 , a conductive ring 2310 is disposed around the through hole 230 .

[0034] The conductive ring 2310 is generally a copper ring or other metal ring, which is disposed at the opening of the through hole 230 on the second surface 220 to enhance the stability of the electrical connection.

[0035] In some specific embodiments, the through holes 230 and the solder joints 2110 are arranged alternately in rows or columns.

[0036] The through holes 230 and the solder joints 2110 are arranged at intervals, so that the connection between the first circuit 2130 and the second electrode 2220 can be evenly dispersed to the greatest extent. Some cardiovascular ultrasonic transducers are very miniaturized. The through holes 230 and the solder joints 2110 are arranged at intervals, and the first circuit 2120 and the second circuit 2210 on the circuit board 20 are dispersed, which facilitates etching the first circuit 2120 and the second circuit 2210 on the circuit board 20.

[0037] In some specific embodiments, the gap between the device layer 10 and the circuit board 20 is filled with insulating glue.

[0038] Since there are piezoelectric units 120 between the device layer 10 and the circuit board 20, there is a gap between the device layer 10 and the circuit board 20. Filling with insulating glue can prevent conduction between the piezoelectric units 110 and increase insulation between the piezoelectric units 110. The insulating glue can also act as an adhesive to firmly connect the device layer 10 and the circuit board 20.

[0039] In some specific embodiments, the piezoelectric unit 120 is made of metal material.

[0040] Metal materials are good conductive substances, which can be made conductive by liquid phase deposition.

[0041] In some specific embodiments, the piezoelectric unit 120 is metal tin.

[0042] Metal tin is a good conductive material, and the solder joint 2110 of tin is relatively low, so it can be easily connected with the solder joint 2110 during soldering.

[0043] In some specific embodiments, the device layer 10 further includes a silicon-on-insulator 30 , and the silicon-on-insulator 30 is connected to the piezoelectric unit 110 and faces away from the piezoelectric unit 120 .

[0044] Silicon on insulator (SOI) is a good insulating material, which can be used as a substrate for a conductive unit. In addition, the substrate material can also be a cavity-type silicon on insulator (CSOI) or a 1-3 type piezoelectric ceramic (single crystal) composite material.

[0045] In some specific embodiments, the SOI 30 and the piezoelectric unit 110 are fixed by a thermal pressing process.

[0046] The hot pressing process is joined together by the hot pressing process.

[0047] In some specific embodiments, the solder joint 2110 and the piezoelectric unit 120 can be soldered together by a reflow soldering method.

[0048] Reflow soldering is also called reflow soldering. It is a welding process that remelts the solder paste pre-allocated to the pad of the printed circuit board to achieve better mechanical and electrical connection between the solder end or pin of the surface mounted component and the pad of the printed circuit board after cooling. Reflow soldering has good stability, compatibility, reliability and anti-interference. When the reflow soldering technology is used for welding, the welding task is completed by local heating, so the components being welded are subjected to less thermal shock, and will not be damaged by overheating, and welding defects such as bridging are also avoided. In addition, the solder in the reflow soldering is disposable, the solder is very pure, and there are no impurities, which ensures the quality of the solder joint 2110. Now more and more electronic components have been converted from through-hole 230 to surface mount, and the reflow soldering process has replaced the wave soldering process to a considerable extent, which is an obvious trend in the welding industry.

[0049] Please refer to Figure 4-Figure 6 Assuming that the array transducer has 54 array elements, the array elements are arranged in an order of 6*9, the array elements are arranged, and the arranged array elements are implanted with tin balls or long copper pillars by means of long copper pillars or solder balls. Finally, the tin balls and copper pillars are integrated with the bottom circuit board 20 or the dedicated integrated circuit; this can reduce interference between circuits and can also make reliable connections; when making connections, the bottom circuit does not need long tin balls and copper pillars, and the circuit board 20 after welding is connected after wire bonding; the circuit and the sensor are connected to the connector as a complete device to transmit data and perform imaging.

[0050] The data interface of the connector is open to the sensor, and the signal processing and impedance matching circuits are placed at the sensor end; the signal processing circuit includes a linear amplification circuit, a time gain compensation circuit, a TGC / LNA and an analog front-end circuit, etc. The impedance matching circuit is placed at the Housing end; The sensor and the host communicate through a coaxial cable with an impedance of 50Ω, characteristic impedance, attenuation of about 3dB / m, and a capacitance of about 105pF / m. The cable is a 46AWG coaxial cable, and the connector at the Housing end is an SMA interface with an impedance of 50Ω. There is a T / R analog switch circuit between the matched signal circuit and the sensor. Each signal passes through the analog switch and the pulse transmitting circuit and is loaded to the sensor end. After the sensor is stimulated, the sensor transmits the signal, which is reflected and received by the pulse receiving circuit. A 46AWG coaxial cable is used to match the pulse transmitter and the sensor. After matching, the signals are simulated and denoised by a low-noise amplifier circuit, and then the time gain compensation is performed by the TGC circuit. After the gain compensation circuit is transmitted to the lower computer for transmission, the signal is converted into a digital signal by the ADC and transmitted to the FPGA for processing. Finally, it is encoded, modulated and demodulated and transmitted to the upper computer software for mapping. In this process, the signal needs to pass through the coaxial cable twice. If the characteristic impedance and transmission loss of the coaxial cable do not meet the requirements, the signal attenuation will be more obvious. In addition, in this transmission process, the signal also needs to pass through the analog switch and T / R Switch, this process will cause signal attenuation. Obviously, the impedance matching circuit can play the role of signal conditioning and impedance adaptation. After the signal is impedance matched, the impedance is about 50Ω. After the transmission, the impedance on the line basically needs to meet the requirements of 50Ω characteristic impedance. Only in this way can the transmission needs be better met. After the signal is transmitted, if there is no characteristic impedance matching, the signal reflection will be stronger. Such reflected signal will be superimposed on the transmission line, causing secondary oscillation, that is, ringing effect. The ringing effect will cause obvious echo tailing, which will affect the frequency domain signal bandwidth and time domain signal time delay. These will affect the quality of the final image, which is specifically manifested as noise on the image and artifacts in the target area of ​​the image. The main reasons for the artifacts are as follows.

[0051] Artifacts are caused by obvious tailing of the signal echo and poor signal quality.

[0052] The main reason for the generation of artifacts is that the echo impedance matching is not appropriate and there is an obvious impedance interface, so the signal will produce reflection superposition, followed by the ringing effect of the echo.

[0053] Finally, artifacts are also generated at interfaces where signal reflections are relatively strong. When the signal is transmitted from one interface to another, there is a significant difference in their impedances. These differences can cause strong reflections, which in turn can cause phantoms or brighter annular circles, which are the causes of artifacts.

[0054] In addition, artifacts are also produced when the signal moves. If the interface of signal detection moves, this will cause relatively strong motion artifacts. Specifically, there are some light and dark stripes on the motion artifact interface. These light and dark stripes will cause motion artifacts, and these artifacts will cause changes in the brightness of the image.

[0055] After FCBGA packaging, the signal needs to be transmitted to the host end. As mentioned above, a 46AWG coaxial cable is required for transmission. This coaxial cable can reduce signal reflection and increase signal transmission. The coaxial cable can also maximize the signal transmission to the analog front-end circuit.

[0056] During the transmission process of the coaxial cable, the signal will form a relatively obvious transmission loss, which is related to the length of the signal line. According to transmission theory, a 1 / 4 wavelength transmission cable is conducive to signal transmission, while the signal lines we usually use have a relatively obvious length mismatch, which will cause signal attenuation and reflection; the connector connected to the signal also has an obvious impedance effect. The connector generally needs to have a characteristic impedance of 50Ω, while the usual connectors are of two types: 75Ω and 50Ω. These two types of transmission cables will obviously cause signal reflection; in this way, during the transmission process, the signal will pass through the connector and the transmission end twice, which will cause obvious signal loss; the signal loss caused by the connector will be more obvious, and the connector also has an obvious impedance matching effect on the signal quality; commonly used connectors include BNC connectors, SMA connectors, and common aviation LEMO connectors, which can have a characteristic impedance of 50Ω or 150Ω.

[0057] Another obvious advantage of FCBGA packaging is that the electrode lead-out ends are relatively small, and the electrode lead-out ends have relatively obvious lead-out terminals. These lead-out terminals need to be arranged around the signal. These signal lead-out terminals can cause relatively obvious signal transmission and changes in the signal transmission characteristic impedance.

[0058] Such discontinuous signal transmission impedance will cause mismatch between signals and changes in characteristics brought about by signal transmission, and finally cause signal changes and distortion, resulting in image artifacts. These are all caused by impedance mismatch, and these mismatches also become the circuit of the entire signal transmission line. In this way, the signal will eventually drown out these noise signals, improving the transmission effectiveness and reliability of the signal; in this way, the signal will have less attenuation during the transmission process, and the signal transmission loss will also be relatively small; the signal reflection attenuation is also relatively small, so that the signal will have obvious impedance characteristics and transmission characteristics during the transmission process, and the attenuation characteristics of the signal during the transmission process are also relatively small, so the signal attenuation will be relatively small, the transmission characteristics will be more obvious, and the attenuation will be relatively small.

[0059] In addition, during the signal transmission process, the signal attenuation is very small, the impedance is relatively small, and the attenuation will also be relatively small. These can cause signal attenuation and impedance characteristics. These impedance characteristics can cause signal attenuation and signal mismatch and changes in signal size, which have obvious advantages and benefits for improving signal sensitivity, so that the signal quality will be improved; the signal transmission characteristics are also significantly improved; for the impact on signal transmission, there are two better advantages: 1. Signal transmission quality and signal transmission effectiveness; these will cause signal attenuation and signal quality changes; signals have obvious advantages for transmission. The main reasons are: signal transmission causes attenuation, and signal transmission also causes reflections. These will cause the signal transmission process to be not very stable, and the quality is not good for signal transmission. The size of the attenuation is related to the quality of the signal cable; there is an obvious reduction effect and signal attenuation effect; the impact on the signal size is also relatively large.

[0060] Finally, the signal transmission process has an obvious impact on the signal quality attenuation and the signal size, which will have a significant impact on the signal attenuation, so that the signal will cause a very obvious change in size; during the signal transmission process, the signal size will be significantly reduced and attenuated during the transmission process; in addition, the signal cable will have obvious changes in cable impedance; these cable impedances will also cause changes in the signal; as the signal attenuation increases, the cable attenuation will also increase; as the signal attenuation decreases, the cable impedance will also decrease, which are all reasons for the signal change; another obvious feature of the signal change is the reduction caused by signal attenuation; these signal reductions will cause changes in the signal, which will have a relatively large impact; ultimately causing changes in the cable; the impact of the signal on transmission will cause changes in the size of the signal. In addition, the FCBGA process can also affect changes in signal quality; general signal transmission circuits will be affected, The quality of signal transmission and the size change caused during the signal transmission process; in this way, the signal will have a more obvious change; FCBGA process, another important process is to conduct as much signal as possible from the CSOI chip to the bottom substrate circuit board 20, this circuit board 20 needs to transmit the signal from the sensor to the connector or to the host end, in the process of signal transmission, the path between the bottom circuit and the signal transmission is the bump solder ball or copper pillar on the CSOI chip; these solder balls or copper pillars can transmit the signal from the CSOI end to the bottom substrate board circuit, in the process of transmission, this way of transmitting signals is obviously offline, this way of transmitting signals, in the process of signal transmission, signal transmission is generally used for communication between sensors and hosts, in this process, signal transmission and transmission process, this process generally has signal reflection and attenuation from the copper pillar or solder ball.

[0061] During the signal transmission process, the signal is transmitted from the copper pillar or solder ball from the CSOI to the connecting cable, and there will be a certain attenuation. The magnitude of the attenuation depends on the attenuated signal. Finally, the signal transmission generally requires vacuum transmission between the cables.

[0062] Usually for signal transmission, due to the transmission between signals, the signal transmission cable and the signal are effectively transmitted, and the effective transmission between signals requires relatively good signal transmission; for signal transmission, the transmission between the transducer and the signal has an obvious signal transmission effect.

[0063] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0064] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent application. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A two-dimensional array ultrasonic transducer based on FCBGA, characterized in that: include: A device layer, the device layer comprising a plurality of piezoelectric units arranged in an array and a positive electrode layer and a negative electrode layer plated on both sides of the piezoelectric units, wherein a conductive column is provided on the positive electrode layer or the negative electrode layer; A circuit board, the circuit board having a first surface, a second surface, and a through hole penetrating the first surface and the second surface; a solder joint, a first circuit, and a first electrode are provided on the first surface, the first circuit is used to connect the solder joint and the first electrode, and the first electrode is arranged at an edge of the circuit board; a second circuit and a second electrode are provided on the second surface, the second circuit is used to connect the second electrode and the through hole, and the second electrode is arranged at an edge of the circuit board; The first surface faces the device layer, and the solder joints and the through holes in combination just correspond to all the conductive pillars.

2. The two-dimensional area array ultrasonic transducer based on FCBGA according to claim 1, characterized in that: The through hole is filled with conductive glue.

3. The two-dimensional array ultrasonic transducer based on FCBGA according to claim 1, characterized in that: On the second surface, a conductive ring is arranged around the through hole.

4. The two-dimensional area array ultrasonic transducer based on FCBGA according to claim 1, characterized in that: The through holes and the solder joints are arranged alternately in rows or columns.

5. The two-dimensional area array ultrasonic transducer based on FCBGA according to claim 1, characterized in that: The gap between the device layer and the circuit board is filled with insulating glue.

6. The two-dimensional array ultrasonic transducer based on FCBGA according to claim 1, characterized in that: The conductive pillar is made of metal material.

7. The two-dimensional area array ultrasonic transducer based on FCBGA as claimed in claim 6, characterized in that: The conductive pillar is made of metal tin.

8. The two-dimensional area array ultrasonic transducer based on FCBGA according to claim 1, characterized in that: The device layer further includes a silicon-on-insulator connected to the piezoelectric unit facing away from the conductive pillar.

9. The two-dimensional area array ultrasonic transducer based on FCBGA as claimed in claim 8, characterized in that: The silicon-on-insulator and the piezoelectric unit are fixed by a thermal pressing process.

10. The two-dimensional array ultrasonic transducer based on FCBGA according to claim 1, characterized in that: The solder joint and the conductive column can be soldered together by a reflow soldering method.

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