A planar scanning ultrasonic phased array

Abstract

The application discloses a plane scanning ultrasonic phased array and relates to the technical field of ultrasonic phased array nondestructive testing. The application utilizes two linear array probes with perpendicular or large included angle array directions to perform cross scanning detection, forms multiple focus lines parallel to the probe plane and perpendicular to the array direction through focusing and deflection, wherein the transmitting probe generates a transmitting focus line, the receiving probe adjusts the focusing rule to generate a receiving focus line, the intersection of the transmitting focus line and the receiving focus line is the detection focus point, the intersection of the transmitting focus line group and the receiving focus line group forms a focus point array, thereby realizing full-area scanning of the detection plane. In the plane scanning process, only two linear array probes are needed to realize plane scanning, so that the cost is greatly reduced. Through active focusing at the transmitting end, post-focusing at the receiving end and cross scanning in the mode of non-point-by-point focusing, the detection plane can be quickly covered, so that the detection efficiency is improved while the cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of ultrasonic phased array nondestructive testing technology, and particularly to a surface scanning ultrasonic phased array. Background Technology

[0002] Ultrasonic phased array nondestructive testing technology is widely used in the industrial field, especially in scenarios requiring high-resolution imaging, such as weld inspection, forging inspection, bolt and shaft part inspection, composite material inspection, plate and bar inspection and other raw material inspection, as well as finished product defect inspection such as water-cooled plate and chip inspection.

[0003] Conventional ultrasonic phased arrays require area array probes for area scanning. An M*N array requires M*N channels in the host computer to operate, which makes it expensive. However, using row and column addressing (RCA) technology can reduce the number of channels in the host computer to M+N, thus significantly reducing the cost of the host computer. However, because RCA probes require separate row and column control, their manufacturing cost is still much higher than that of conventional probes.

[0004] In chip packaging inspection, target material inspection, and brazing of water-cooled plates for new energy batteries, high-resolution surface scan images are required. Existing technology uses a high-frequency conventional ultrasonic point-focusing probe to obtain surface scan images by using a small focal point for rapid, small-pitch grating scanning. Although the single-line scanning speed is fast, the overall inspection efficiency is still low due to the small spacing between adjacent lines and the large number of round trips. Summary of the Invention

[0005] This invention provides a surface scanning ultrasonic phased array, which can solve the problems existing in the prior art.

[0006] This invention provides a planar scanning ultrasonic phased array, comprising:

[0007] Two linear arrays, each of which consists of multiple single-chip arrays arranged in an array, and the array directions of the two linear arrays are not parallel;

[0008] One linear array serves as the transmitter, and the other linear array serves as the receiver.

[0009] The two linear arrays are combined to form an ultrasonic scanning probe pair for surface scanning. The deflection angle and focal depth of the synthesized sound beam of the entire array are controlled by the delay of each single crystal in the preset transmitter. The ultrasonic beam emitted by the transmitter based on the emission delay time is focused at the focal depth in the deflection plane to form a focal area. In the direction perpendicular to the deflection plane, the beam emitted by each single crystal diffuses along the length of the single crystal, so that the focal area extends into a focal line.

[0010] Wherein, the deflection plane is the plane formed by the direction of the linear array and the direction of beam propagation;

[0011] Each single crystal in the receiving end receives the echo beam reflected by the ultrasonic beam. By adjusting the receiving delay time of each single crystal, the focusing position of the receiving beam is adjusted so that each focus is distributed along a preset receiving line to form a receiving focal line group, which is used to scan the dot matrix at the intersection of the transmitting focal line and the receiving focal line of the detection surface.

[0012] By changing the focusing law at the transmitting end, multiple different transmitting focal lines are formed in the detection area. The receiving end forms multiple receiving focal lines using the same or different focusing laws, which are used to scan the detection area.

[0013] Preferably, the two linear arrays are perpendicular or at an angle between 45° and 135°.

[0014] Preferably, the position of the probe pair composed of the two linear arrays can be moved to scan different areas.

[0015] Preferably, the two linear arrays are set to a fixed tilt angle to increase the scanning range.

[0016] Preferably, the detection host control adjusts the time delay parameter in the focusing law of the receiving end to control the focal line to focus at different depth positions, so as to scan different depths inside the object and realize three-dimensional scanning.

[0017] Preferably, the angle between the array directions of the two linear arrays in the plane is adjusted to adjust the resolution of the arrays in different directions.

[0018] Preferably, the transmitter is excited in a non-focused state, and the receiver is focused only on the transmitter for area or volume scanning.

[0019] Preferably, the transmitter and receiver are arranged in the same housing, or in two housings with fixed relative positions.

[0020] This invention provides a planar scanning ultrasonic phased array, which has the following advantages compared with the prior art:

[0021] This invention utilizes two linear array probes with non-parallel array directions and non-parallel single-chip length directions to perform cross-scan detection with one transmitter and one receiver. Multiple focal lines parallel to the probe plane and perpendicular to the array direction are formed through focusing and deflection. The transmitting probe actively generates the focal lines, while the receiving probe adjusts its focusing rule to generate the receiving focal lines. The intersection of the transmitting and receiving focal lines is the detection focus. The intersection of the transmitting and receiving focal line groups forms a focal array, thereby achieving full-area scanning of the detection surface. During this surface scanning process, only two linear array probes are needed to achieve surface scanning, significantly reducing costs. Furthermore, by adjusting the focusing rule at the receiving end, point-by-point detection of one line can be completed with a single transmission, allowing for rapid coverage of the detection surface, thus improving detection efficiency while reducing costs. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the surface scanning principle of a non-parallel arranged linear array probe of a surface scanning ultrasonic phased array, provided in an embodiment of the present invention.

[0023] Figure 2 This is a schematic diagram of a planar scanning ultrasonic phased array provided in an embodiment of the present invention, in which the probe tilts to form a planar angle to reduce the phased array deflection angle and increase the coverage area for scanning.

[0024] Figure 3 A schematic diagram of mounting the transmitting and receiving probes on a flat wedge with sound insulation design in a planar scanning ultrasonic phased array according to an embodiment of the present invention;

[0025] Figure 4 This is a schematic diagram of a planar scanning ultrasonic phased array transmitter and receiver probe installed on a wedge block with sound insulation design in the middle for detection, as provided in an embodiment of the present invention.

[0026] Figure 5 This is a schematic diagram of a surface scanning ultrasonic phased array provided in an embodiment of the present invention, in which two probes are arranged on the same side of the area to be detected, allowing the wedge to rotate relative to each other at an angle on the detection surface;

[0027] Figure 6 This is a schematic diagram of two probes of a surface scanning ultrasonic phased array arranged on both sides of the area to be detected, as provided in an embodiment of the present invention.

[0028] Figure 7 This is a schematic diagram illustrating the resolution in two directions of an orthogonal array of a surface-scanning ultrasonic phased array, provided as an embodiment of the present invention.

[0029] Figure 8 A schematic diagram of the resolution in two directions when the included angle of the planar scanning ultrasonic phased array is 120 degrees, provided for an embodiment of the present invention;

[0030] Figure 9This is a schematic diagram illustrating an adjustment focusing rule for a planar scanning ultrasonic phased array provided in an embodiment of the present invention, forming focusing at different depths.

[0031] Figure 10 This is a schematic diagram of the probe arrangement and focusing top of a planar scanning ultrasonic phased array provided in an embodiment of the present invention;

[0032] Figure 11 This is a schematic diagram of the sampling point distribution during circumferential detection of a surface-scanning ultrasonic phased array, provided in an embodiment of the present invention.

[0033] Among them: 11, transmitting chip group, 12, transmitting sound ray group, 13, transmitting focal line group, 14, receiving chip group, 15, receiving sound ray group, 16, receiving focal line group, 17, area scanning area. Detailed Implementation

[0034] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0035] See Figure 1 This invention provides a planar scanning ultrasonic phased array, illustrating a transmitting wafer group 11, a transmitting acoustic ray group 12, a transmitting focal line group 13, a receiving wafer group 14, a receiving acoustic ray group 15, a receiving focal line group 16, and a planar scanning area 17. The transmitting and receiving wafer groups are arranged coplanarly and orthogonally. The transmitting wafer group forms a series of focal lines through deflection and focusing, while the receiving wafer group forms a focal line group perpendicular to the transmitting focal line group by receiving and focusing the received reflected echoes. The point where these two sets of focal lines intersect is the detection point within the area. Figure 1 A total of 4*6 points were detected in the area shown.

[0036] The principle is as follows: Linear array probes, through focusing and deflection or focusing and electronic scanning, can form a series of focal lines that are focused along the main axis and naturally diffused along the secondary axis. These focal lines are parallel to the probe plane and perpendicular to the array direction. When using two probes for one-to-one transmission and one-to-reception detection, the transmitting probe can actively generate focal lines. After receiving the signal, the receiving probe can adjust the focusing rule of the received signal by the detection host, and generate the receiving focal lines after post-processing. When the array directions of the transmitting and receiving probes are not parallel, a series of focal points are formed at the convergence of the two sets of focal lines. At this time, the detection of a series of points on this transmitting focal line is completed with only one transmission. Then, the focusing rule is changed to form another transmitting focal line, and the receiving probe also performs reception and focusing. This process is repeated to form a surface scan of a certain area using a pair of linear array probes. By adjusting the focusing rule and moving the focal line depth, a three-dimensional scan of a certain volume can be completed. Compared with traditional area array detection technology, this technology greatly reduces the number of host channels required for the same aperture. At the same time, compared with row-column addressing (RCA) technology, it significantly reduces the cost of probes. Due to the separation of transmission and reception, the probe arrangement is more flexible and can adapt to more detection needs.

[0037] When a linear array probe deflects and focuses, a "focal point" is formed on the plane of probe deflection. However, due to the natural diffusion of the linear array probe along the length of the wafer (called the secondary axis), the "focal point" in three-dimensional space is actually a line segment parallel to the probe plane. The length of this line segment is the diffusion length of the passive axis of the phased array probe at that position. When two linear array probes are not arranged parallel to each other and focus on the same position in space, the two focal lines intersect to form a spatial focal point. In this way, a pair of low-cost phased array linear probes can achieve a certain range of area scanning effect.

[0038] The focusing principle in ultrasonic phased array systems involves adjusting the time delay of ultrasonic waves emitted or received by each array element to focus the sound waves at a specific location. This principle is based on the principle of wave interference: when ultrasonic waves emitted by multiple array elements (wave sources) meet at a point in space, if the waves are in phase, the sound pressure is enhanced by superposition (constructive interference); otherwise, it is weakened (destructive interference). By accurately calculating the distance from each array element to the target focal point and setting the corresponding time delay, the sound waves from all array elements can arrive at the target point synchronously, forming the maximum sound pressure.

[0039] The delay rule is a time delay sequence that controls the transmission or reception of ultrasonic waves by each array element, used to achieve beam deflection (electronic scanning) and focusing. It is the specific means of implementing the focusing rule and determines the direction of sound wave propagation and the focusing position. The delay rule is a time delay sequence that controls the transmission or reception of ultrasonic waves by each array element, used to achieve beam deflection (electronic scanning) and focusing. It adjusts the phase of the transmitted or received sound waves by setting different time delays for each array element, so that the sound beam forms constructive interference in a specific direction.

[0040] like Figure 1 As shown, two linear array probes are arranged non-parallel (they can be orthogonal or at other angles). One probe acts as the transmitting probe, forming a focal line on the detection surface through deflection and focusing by a certain time delay combination. The other probe acts as the receiving probe, transmitting the signals received by each chip to the host. By changing the delay rule, a series of receiving focuses are formed, creating a row of intersections with the focal line of the transmitting probe, thus completing the detection of the transmitting focal line. Then, the transmitting probe changes the delay rule to form another transmitting focal line on the detection surface. After receiving the signal, the receiving probe focuses the signal using the same or different focusing rules as the previous steps, forming another row of focal points. This process is repeated to complete the area scanning of a local region.

[0041] After completing the surface scan, if volume detection is required, the focus is moved to another plane by adjusting the focusing rule and the above process is continued, finally completing the 3D scan within the specified volume range.

[0042] In the above description, after the first line of focus detection is completed, the transmitting probe and / or receiving probe can be moved to form another line of focus without changing the focusing law by changing the physical position.

[0043] The two methods above can also be combined to change the focusing rule and adjust the probe position to form the desired focal combination.

[0044] like Figure 2 An improved method is demonstrated, which arranges two linear array probes opposite each other at a certain plane tilt angle, which can reduce the beam deflection angle, optimize the focusing effect, and increase the scanning range. Figure 2 The array includes an emitting chip group 21, an emitting acoustic ray group 22, an emitting focal line group 23, a receiving chip group 24, a receiving acoustic ray group 25, a receiving focal line group 26, and a surface scanning area 27.

[0045] like Figure 3 One method of use is demonstrated, in which the transmitting and receiving probes are mounted on a flat wedge with a sound-insulating design in the middle for testing, including a transmitting array 31, a receiving array 32, a flat wedge 33, and a sound-insulating layer 34; or a roof corner is added to the wedge so that the two probes are aligned. Figure 2 A similar surface tilt angle is used to achieve optimized detection results.

[0046] like Figure 4 A method of use is demonstrated, in which the transmitting and receiving probes are mounted on a wedge with a sound-insulating design in the middle for testing. This wedge includes a transmitting array 41, a receiving array 42, a flat wedge 43 with coplanar transmitting and receiving sides, and a sound-insulating layer 44; or an angle is added to the wedge to make the two probes face each other. Figure 2Similar tilt angles are used to achieve optimized detection results.

[0047] like Figure 5 and Figure 6 This demonstrates a method of use in which the transmitting and receiving probes are mounted on two wedges for testing, and the two probes can be placed on the same side of the area to be tested (e.g., ...). Figure 5 As shown, this includes a transmitting probe 51, a transmitting probe wedge 52, a receiving probe 53, a receiving probe wedge 54, and a weld 55, which can also be placed on both sides of the area to be inspected (e.g., Figure 6 As shown, it includes a transmitting probe 61, a transmitting probe wedge 62, a receiving probe 63, a receiving probe wedge 64, and a weld 65; if placed on the same side, the two wedges can be rotated relative to each other at an angle on the detection surface to obtain optimized detection results.

[0048] like Figure 7 and Figure 8 An improved method is demonstrated where, in situations where surface inspection requires increased resolution in one direction but less so in another (e.g., for shaft or bolt parts where the presence and depth of surface cracks are of greater concern than length measurement), the probe array's directional angle is not limited to orthogonal arrangement. For example, when the angle is 90 degrees, the resolution of both diagonals is 1.41d (where d is the distance between adjacent scan points on a focal line). Figure 7 As shown, the focal length distance is labeled 71, and the distance between the two oblique focal points, which is 1.4 times the focal length distance, is labeled 72; when the included angle is 120 degrees, the resolution of the minor axis increases to 1.15d, and the resolution of the major axis decreases to 2d, as shown. Figure 8 As shown, the focal length distance is marked as 81, the shorter distance between the two oblique focal points is marked as 1.15 times the focal length distance as 82, and the shorter distance between the two oblique focal points is marked as 2 times the focal length distance as 83. Therefore, when inspecting shafts or bolts, aligning the short shaft with the radial direction of the cylinder can achieve better inspection results.

[0049] Example 1:

[0050] Based on the above principles, this invention designs a water immersion detection system for chip packaging; the specific workflow is as follows:

[0051] When inspecting small-sized products such as chips, specifically when the product size is smaller than the overlapping area of ​​the sound fields of the dual probes, the inspection process can be completed without moving the probes. The loading and unloading system places the product to be inspected in the designated position. The probes, either fixed in this position or moved from elsewhere to the inspection area, receive the start inspection signal, and the transmitting probe emits the first focal line. The receiving probe receives the signal, and the inspection host focuses and collects the signals at each focal point along the focal line. Then, the transmitting probe emits the second focal line, and the receiving probe collects the signals at each focal point along the focal line, repeating this process until the entire product inspection is completed. If it is a single-piece loading, the unloading system determines whether to send the product to the next process or to the non-conforming temporary storage area based on the inspection results. If it is a batch loading on a pallet, the probes move to the next product and repeat the above inspection process. After the entire pallet inspection is completed, the loading and unloading system removes the pallet from the inspection area, and the mechanical mechanism picks out the non-conforming products and places them in the temporary storage area based on the inspection results, while the other products proceed to the next process.

[0052] Example 2:

[0053] Based on the above principles, this invention designs a water immersion testing system for target material testing or brazing testing of water-cooled plates in new energy batteries; the specific workflow is as follows:

[0054] When the product to be tested is large and the sound field cannot be completely covered at the same location, testing needs to be performed while the product is in motion. Specifically, after the product is in place, the probe moves to the starting point of the test. The transmitting probe emits a focal line, and the receiving probe receives the signal. The host computer completes the scanning of each point on the focal line by receiving and focusing. At the same time, the probe moves a short distance towards the transmitting probe array and continues the above transmission and reception process until the transmitting focal line moves out of the test area. If the product is wide and a single test cannot cover the entire width, the probe can be moved a short distance (not greater than the length of the transmitting focal line) in a direction parallel to the transmitting focal line to perform a grating scan and continue the above process until the test is completed.

[0055] Example 3:

[0056] Based on the above principles, this invention designs a system for detecting circumferential defects in cylindrical parts such as bolts or shafts; the specific workflow is as follows:

[0057] Two linear array probes, such as Figure 9As shown, the transmitting probe, positioned at the end of a bolt or shaft-like part, emits a focal line focused at a certain depth, passing through the outer circular surface of the cylinder. The receiving probe receives and focuses the signal, forming a series of receiving focal lines, thus completing the detection at each point where the transmitting focal lines intersect. The transmitting array is labeled 91, the transmitting sound lines focused at different depths are labeled 92, the transmitting focal lines at different depths are labeled 93, the receiving array is labeled 94, the receiving sound lines focused at different depths (each transmitting sound line corresponds to a set of receiving sound lines labeled 95), the receiving focal lines focused at different depths (each transmitting focal line corresponds to a set of receiving focal lines labeled 96), the shaft or bolt-like part is labeled 97, and the center process hole of the detection surface is labeled 98. Then... Figure 10 As shown, adjust the focusing depth of the transmitting and receiving focal lines to complete the detection at the next depth. Adjust the focusing depth sequentially until the detection is completed within the entire depth range, then return to the shallowest focusing depth and repeat the cycle. The transmitting array is labeled 101, the receiving array is labeled 102, the single transmitting ray is labeled 103, the group of receiving rays is labeled 104, the shaft or bolt parts are labeled 105, and the process hole at the center of the detection surface is labeled 106.

[0058] While the above-mentioned rapid detection is performed in a loop, the probe is rotated about the axis of the cylinder, forming a circumferential detection of the outer surface within a certain range. The trajectory distribution of the detection points on each plane is as follows: Figure 11 As shown, the emission focal line at a certain focusing depth is labeled 111, the receiving focal line at the same focusing depth is labeled 112, and the scanning point array at that focusing depth is labeled 113. This detection method is particularly suitable for detecting hollow shafts or bolts with a central hole.

[0059] The two linear array probes of this invention, used for surface scanning, can further reduce probe costs while expanding the freedom in probe arrangement and parameter selection. In the field of chip packaging inspection, the inspection of target materials and the brazing of water-cooled plates for new energy batteries require high-resolution surface scan images. Existing technologies use high-frequency point-focusing probes to obtain surface scan images by using small focal points for rapid, small-pitch grating scanning. Although the single-line scanning speed is fast, the overall detection efficiency is still low due to the small spacing between adjacent lines and the large number of round trips. The surface scanning system designed based on the principle of this invention can significantly improve the detection efficiency.

[0060] In the field of inspection of cylindrical parts such as bolts and shafts, area array probes are expensive and the excitation aperture is limited by the total number of channels of the inspection host, making it impossible to use area array probes with larger apertures for point focusing inspection. Conventional linear array probes are greatly affected by thread interference due to their large focal length, resulting in poor detection of micro-cracks. However, the area scanning system designed in this invention can effectively reduce costs, improve inspection results, and increase the detection rate of micro-defects.

[0061] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A planar scanning ultrasonic phased array, characterized in that, include: Two linear arrays, each of which consists of multiple single-chip arrays arranged in an array, and the array directions of the two linear arrays are not parallel; One linear array serves as the transmitter, and the other linear array serves as the receiver. The two linear arrays are combined to form an ultrasonic scanning probe pair for surface scanning. The deflection angle and focal depth of the synthesized sound beam of the entire array are controlled by the delay of each single crystal in the preset transmitter. The ultrasonic beam emitted by the transmitter based on the emission delay time is focused at the focal depth in the deflection plane to form a focal area. In the direction perpendicular to the deflection plane, the beam emitted by each single crystal diffuses along the length of the single crystal, so that the focal area extends into a focal line. Wherein, the deflection plane is the plane formed by the direction of the linear array and the direction of beam propagation; Each single crystal in the receiving end receives the echo beam reflected by the ultrasonic beam. By adjusting the receiving delay time of each single crystal, the focusing position of the receiving beam is adjusted so that each focus is distributed along a preset receiving line to form a receiving focal line group, which is used to scan the dot matrix at the intersection of the transmitting focal line and the receiving focal line of the detection surface. By changing the focusing law at the transmitting end, multiple different transmitting focal lines can be formed in the detection area. The receiving end uses the same or different focusing laws to form multiple receiving focal lines for scanning the detection surface.

2. The planar scanning ultrasonic phased array according to claim 1, characterized in that, The angle between the two linear arrays is between 45° and 135°.

3. The planar scanning ultrasonic phased array according to claim 1, characterized in that, The probe pair, composed of two linear arrays, can be moved to scan different areas.

4. The planar scanning ultrasonic phased array according to claim 1, characterized in that, The two linear arrays are set to a fixed plane tilt angle to increase the scanning range.

5. A planar scanning ultrasonic phased array according to claim 1, characterized in that, The detection host control adjusts the time delay parameter in the focusing law of the receiver to control the focal line to focus at different depth positions, which is used to scan different depths inside the object and realize three-dimensional scanning.

6. The planar scanning ultrasonic phased array according to claim 1, characterized in that, The angle between the array directions of the two linear arrays in the plane is adjusted to adjust the resolution of the arrays in different directions.

7. The planar scanning ultrasonic phased array according to claim 1, characterized in that, The transmitter is excited in a non-focused state, and the receiver is focused on receiving the signal for area or volume scanning.

8. The planar scanning ultrasonic phased array according to claim 1, characterized in that, The transmitter and receiver are arranged in the same housing, or in two housings with fixed relative positions.

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