An ultrasonic transducer and method of manufacture

Abstract

The application discloses an ultrasonic transducer and a manufacturing method, and relates to the technical field of ultrasonic transducers, wherein the ultrasonic transducer comprises: a flexible plate used for being connected with a chip as a whole, a plurality of array element pads are arranged on the surface of the flexible plate; a plurality of transducer array elements, the transducer array elements are covered with conductive layers, and the transducer array elements are arranged in one-to-one correspondence with the array element pads; and a supporting element arranged between the transducer array elements and the array element pads, the supporting element is made of plastic material with conductive capacity, and the supporting element can be deformed in extension in response to pressure to couple the array element pads and the conductive layers of the transducer array elements; the ultrasonic transducer and the manufacturing method are characterized in that the supporting element is arranged between the transducer stack and the flexible plate, the transducer array elements and the array element pads can be in good contact through the deformation of the supporting element, and the spacing between the transducer stack and the flexible plate is increased, so that the selection of a falling point of a cutting knife is facilitated.

Description

Technical Field

[0001] This invention relates to the field of ultrasonic transducer technology, and more specifically, to an ultrasonic transducer. Furthermore, this invention also relates to a method for manufacturing the aforementioned ultrasonic transducer. Background Technology

[0002] Under normal conditions, large-plane flexible circuit boards have a certain degree of warping deformation, and this warping deformation has a certain degree of uncertainty. When they are bonded to chip components, the degree of warping and uncertainty of this warping shape will increase. Moreover, after bonding, the straightening difficulty of the flexible circuit board also increases. Therefore, the probability of the bonded flexible circuit board having a warping shape is relatively high.

[0003] When manufacturing ultrasonic transducers, after the transducer stack is bonded to the flexible circuit board with adhesive, the warping deformation of the flexible circuit board can cause some array elements of the transducer stack to fail to make normal contact and conduction with the pads of some array elements on the flexible circuit board, resulting in array element failure.

[0004] Furthermore, after the transducer stack and flexible circuit board are bonded together, the transducer stack needs to be cut to form several independent transducer elements. However, due to the warping deformation of the flexible circuit board, the bonding surface between the flexible circuit board and the transducer stack is not flat. This makes the selection of the cutting blade height problematic. If the cutting point is too high, there is a risk that some transducer stacks cannot be completely cut and separated, resulting in a short circuit. If the cutting point is too low, there is a risk that the flexible circuit board will be partially cut and damaged.

[0005] In summary, how to solve the problems of imperfect transducer stacking caused by the warping deformation of flexible circuit boards and the inability of transducer elements to conduct properly between element pads is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide an ultrasonic transducer in which a conductive support element is provided between the transducer stack and the flexible plate. Through the plastic extension deformation of the support element, the transducer array elements in the transducer stack and the array element pads on the flexible plate can make good contact. The spacing between the transducer stack and the flexible plate is increased, which facilitates the selection of the cutting point of the cutting blade and avoids short circuits caused by incomplete separation of the transducer array elements or damage to the flexible plate caused by cutting during the cutting process.

[0007] Another objective of this invention is to provide a manufacturing method for the aforementioned ultrasonic transducer, which, by planting a support element and applying positive pressure, enables the support element to undergo plastic deformation in response to the positive pressure, ensuring good contact between the transducer array elements and the array element pads, and creating a gap between the transducer stack and the flexible plate, thereby reducing the difficulty of cutting.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] An ultrasonic transducer, comprising:

[0010] A flexible board is used to connect with the chip as a whole, and the surface of the flexible board is provided with multiple array element pads;

[0011] Multiple transducer array elements, each transducer array element is covered with a conductive layer, and each transducer array element is configured in a one-to-one correspondence with the array element pads.

[0012] A support element is disposed between the transducer element and the element pad. The support element is made of a conductive plastic material and is capable of stretching and deforming in response to pressure to couple the element pad to the conductive layer of the transducer element.

[0013] Preferably, the supporting element is an ellipsoidal or spherical geometric shape, and the height of the supporting element is greater than the warpage of the flexible plate.

[0014] Preferably, the projected area of ​​the support element on the flexible plate is smaller than the projected area of ​​the array element pad on the flexible plate.

[0015] Preferably, the height of the support element ranges from [value missing]. , where d represents the diameter of the element pad and w represents the warpage of the flexible board.

[0016] Preferably, an adhesive is further filled between the flexible plate and the transducer array element, and the adhesive is distributed between the support elements for mechanically connecting the flexible plate and the transducer array element.

[0017] Preferably, the curing temperature of the adhesive is a first temperature, and the support element is able to stretch and deform in response to pressure at an environment below the first temperature.

[0018] Preferably, the multiple transducer array elements are distributed in a one-dimensional linear array, a ring array, a sector array, or a two-dimensional matrix.

[0019] A manufacturing method for manufacturing an ultrasonic transducer as described in any one of the above, comprising:

[0020] A conductive coating is applied to the outside of the acoustic components to form a transducer stack, and support elements are planted one by one at the array element pads of the flexible board.

[0021] The transducer stack is positioned on the side of the flexible plate where the support element is grown, and adhesive is filled into the gap between the transducer stack and the flexible plate.

[0022] Applying positive pressure causes the support element to deform in order to connect the array pads and the transducer stack respectively, and the adhesive flows as the support element deforms;

[0023] Curing the adhesive;

[0024] The transducer stack is cut to form multiple transducer array elements.

[0025] Preferably, before planting the support elements at the corresponding positions of the array pads on the flexible board, the method further includes:

[0026] On the other side of the flexible plate used to grow the support element, the flexible plate is soldered to a special chip or component using solder.

[0027] Preferably, the step of cutting the transducer stack to form a plurality of transducer array elements includes:

[0028] Control the bottom surface of the cutting blade to move along the Z-axis to the blade landing point A;

[0029] Control the cutting blade to advance along the X-axis or Y-axis to cut the transducer stack;

[0030] The height of the blade drop point A is within the height range of the support element, and the height of the blade drop point A is between the bottom surface height of the transducer stack and the top surface height of the flexible plate.

[0031] Preferably, the cutting parameters include at least one of the following:

[0032] The plane containing the highest point of the flexible plate is the base plane, and the height of the knife drop point A is higher than the height of the base plane of the flexible plate;

[0033] The distance between the cutting point A and the edge of the transducer stack is not less than a preset distance L1.

[0034] The ultrasonic transducer provided by this invention has at least the following advantages compared with the prior art:

[0035] 1. Support elements are set on the flexible plate, and the support elements are made of plastic material with conductive properties. When the transducer stack is bonded to the flexible plate, pressure is applied to cause the support elements at different positions to undergo different degrees of plastic deformation, thereby ensuring that the array element pads on the surface of the flexible plate with warping deformation can be effectively electrically connected to the transducer array elements.

[0036] 2. When cutting the transducer stack, the support elements on the flexible board increase the distance between the transducer stack and the surface of the flexible board. Therefore, there is a large height difference between the lowest point of the transducer stack and the highest point of the flexible board, which facilitates the selection of the cutting point height and reduces the processing difficulty. This ensures that the transducer stack can be cut to the appropriate depth without damaging the flexible board, regardless of whether the flexible board is in a warped state.

[0037] The manufacturing method provided by this invention is used to manufacture the above-mentioned ultrasonic transducer and has the same beneficial effects. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0039] Figure 1 This is a schematic diagram of a design scheme in the prior art;

[0040] Figure 2 This is an assembly diagram of the specific chip assembly, flexible board, and transducer stack provided by the present invention;

[0041] Figure 3 This is a top view of the specific ultrasonic transducer provided by the present invention;

[0042] Figure 4 This is a schematic diagram of the cutting tool's feed path during the specific transducer stack cutting provided by the present invention;

[0043] Figure 5 This is a schematic diagram of the assembly of the flexible plate and transducer stack when the specific support element provided by the present invention is not deformed under pressure;

[0044] Figure 6 This is a schematic diagram of the assembly of the flexible plate and transducer stack when the other supporting element provided by the present invention is not deformed under pressure;

[0045] Figure 7 This is a schematic diagram of the assembly of the flexible plate and transducer stack after the specific support element provided by the present invention is deformed under pressure.

[0046] Figure 8 This is a schematic diagram of the assembly of the flexible plate and transducer stack after the second type of support element provided by the present invention is deformed under pressure.

[0047] Figure 9This is a schematic diagram of the assembly of the flexible plate and transducer stack after the third type of support element provided by the present invention is deformed under pressure.

[0048] Figure 10 This is a schematic diagram of the assembly of the flexible plate and transducer stack after the fourth type of support element provided by the present invention is deformed under pressure.

[0049] Figures 1-10 middle:

[0050] 1. Transducer stack; 11. Transducer element; 2. Flexible board; 21. Input / output port pads; 22. Element pads; 3. Solder balls; 4. Chip assembly; 5. Supporting element; 6. Adhesive.

[0051] Figure 4 middle:

[0052] The trajectory of the hollow triangle is the feed trajectory of the cutting tool;

[0053] Point A is the point where the cutting blade lands.

[0054] Figures 5-10 middle:

[0055] M is the plane containing the lowest point of the transducer stack;

[0056] N is the plane where the highest point of the flexible plate is located. Detailed Implementation

[0057] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0058] The core of this invention is to provide an ultrasonic transducer, in which a conductive support element is provided between the transducer stack and the flexible plate. Through the plastic extension and deformation of the support element, the transducer array elements in the transducer stack and the array element pads on the flexible plate can make good contact. It also increases the spacing between the transducer stack and the flexible plate, which facilitates the selection of the cutting point and avoids short circuits caused by incomplete separation of the transducer array elements or damage to the flexible plate caused by cutting during the cutting process.

[0059] Another core aspect of this invention is to provide a manufacturing method for the aforementioned ultrasonic transducer. By planting a support element and applying positive pressure, the support element can undergo plastic deformation in response to the positive pressure, ensuring good contact between the transducer array elements and the array element pads, and creating a gap between the transducer stack and the flexible plate, thus reducing the difficulty of cutting.

[0060] Please refer to Figure 2 An ultrasonic transducer, comprising:

[0061] Flexible board 2 is used to connect with dedicated chips or components as a whole, and multiple array pads 22 are mounted on the surface of flexible board 2.

[0062] Multiple transducer array elements 11 are provided, each transducer array element 11 is covered with a conductive layer, and each transducer array element 11 is set in a one-to-one correspondence with the array element pad 22.

[0063] Support element 5 is disposed between transducer element 11 and element pad 22. Support element 5 is made of a plastic material with conductive properties. Support element 5 can stretch and deform in response to pressure to couple the element pad 22 and the conductive layer of transducer element 11.

[0064] Due to its inherent characteristics, the flexible board 2 has a warped surface, and this warping shape has a certain degree of uncertainty. Moreover, after the flexible board 2 is bonded to the chip component 4, the degree of warping increases. Furthermore, during the bonding process, the warping deformation of the flexible board 2 is uncertain and difficult to recover due to the influence of the process. Therefore, the final degree of warping of the flexible board 2 is difficult to detect or estimate in advance.

[0065] Moreover, the flexible board 2 is fixed by the chip assembly 4. Forcibly straightening the flexible board 2 can easily damage the chip assembly 4, resulting in an increase in the product defect rate.

[0066] The transducer stack 1 forming the transducer element 11 has high rigidity, so it can maintain a relatively flat surface. Even if the transducer stack 1 warps due to insufficient rigidity, the warping shape of the transducer stack is difficult to be completely consistent with the warping shape of the flexible plate 2. Therefore, when the transducer stack 1 is bonded to the flexible plate 2 which has a warped shape, there is a very likely area between them that is not bonded. That is, the conductive layer of the transducer element 11 formed by the transducer stack 1 and the corresponding element pad 22 cannot generate effective electrical conduction, which affects the use of the ultrasonic transducer.

[0067] Therefore, a support element 5 is provided between the transducer element 11 and the element pad 22. The support element 5 is made of a plastic material with conductive properties, such as gold or gold alloy. It can plastically deform in response to the normal pressure between the transducer element 11 and the flexible plate 2, thereby actively adapting to the warping deformation of the flexible plate 2 and / or the transducer stack 1, which may have different degrees of warping. Even when the distance between the flexible plate 2 and the transducer stack 1 is not fixed, the conductive layer of the transducer element 11 can still be effectively electrically connected to the element pad 22 at the corresponding position.

[0068] In some embodiments, the support element 5 is an ellipsoidal or spherical geometry, and the height of the support element 5 is greater than the warpage of the flexible plate 2.

[0069] When the flexible plate 2 has a warped shape, the height of the top of the support element 5 is ensured to be greater than the warp of the flexible plate 2. This ensures that when the cutting depth is close to the depth near the top of the support element 5, the flexible plate or transducer stack 1 will not be damaged. Alternatively, the height of the support element 5 can be set to be a multiple of the warp, for example, twice the height. In this case, the cutting position can be designed at (1 / 2H, 1H) of the support element, meaning the height of the support element 5 compensates for the warp. For example, the lower edge of the cutting blade only reaches half the height of the support element without contacting the flexible plate 2. Specifically, the warp can be a preset range value measured multiple times during production, or a determined value actually measured before cutting. In practical applications, the method for obtaining the warp can be selected and applied according to actual needs.

[0070] The warpage of flexible plate 2 is obtained by measuring the vertical height difference between the lowest point of flexible plate 2 and the base plane, using the plane containing the highest point of the surface of flexible plate 2 as the base plane. This height difference is the warpage of flexible plate 2. Figures 5-10 In the diagram, plane N is the base plane of flexible plate 2;

[0071] When planting the support element 5, the initial height of the support element 5 needs to be greater than the warpage of the flexible plate 2. That is, the upper surface of the support element 5 distributed at different positions on the flexible plate 2 is higher than the base surface of the flexible plate 2. Therefore, if... Figure 5 and Figure 6 As shown, during the bonding of the transducer stack 1, the conductive layer on the lower surface of the transducer stack 1 can abut against part of the upper surface of the support element 5, such as... Figures 7-10 As shown, when a positive pressure is applied to the transducer stack 1, the support element 5 that is already in contact can undergo plastic deformation, be compressed along its own height direction, and be extended along its own length or width direction, thereby increasing the contact area between the conductive layer on the lower surface of the transducer stack 1 and the upper end face of the support element 5 that was not originally contacted, until all support elements 5 are in contact with the conductive layer on the lower surface of the transducer stack 1. Generally speaking, ignoring the slight recovery of chip warpage after pressure, the pressure height will be greater than the warpage.

[0072] Since the height of the support element 5 is greater than the warpage of the flexible plate 2, that is, when the conductive layer on the lower surface of the transducer stack 1 abuts against the support element 5 at the lowest point of the surface of the flexible plate 2, the height of the lower surface of the transducer stack 1 is still higher than the base surface of the flexible plate 2. Therefore, when cutting the transducer stack 1, it is only necessary to make the cutting point within the height range between the base surface and the lower surface of the transducer stack 1 to complete the complete cutting of the transducer stack 1 without damaging the flexible plate 2.

[0073] Meanwhile, the support element 5 adopts an ellipsoidal or spherical geometry, and its upper and lower ends have a small contact area with the flexible plate 2 and the transducer stack 1. The spherical contact of the spherical part can disperse the stress over a larger area. When the support element 5 is compressed, the stress is evenly transmitted along the spherical surface with the spherical surface as the fulcrum, making it easier to generate adaptive deformation. The total amount of material that needs to flow to undergo plastic deformation is small. Moreover, after plastic deformation, the contact area between the support element 5 and the flexible plate 2 and the transducer stack 1 will inevitably increase. Therefore, the support element 5 adopts an ellipsoidal or spherical geometry, which can effectively control the increased contact area and avoid short circuits of multiple array element pads 22 caused by it exceeding the area of ​​the array element pads 22.

[0074] In some embodiments, the projected area of ​​the support element 5 on the flexible plate 2 is smaller than the projected area of ​​the array pad 22 on the flexible plate 2.

[0075] like Figures 5-10 As shown, when the support element 5 undergoes plastic deformation in response to the positive pressure from the transducer stack 1 and the flexible plate 2, its horizontal cross-sectional area increases. When the projected area of ​​the support element 5 on the flexible plate 2 is greater than the projected area of ​​the array pad 22 on the flexible plate 2, there is a possibility that adjacent support elements 5 will short-circuit after plastic deformation. To avoid short circuits, when planting the support element 5, this application sets the projected area of ​​the support element 5 on the flexible plate 2 to be smaller than the projected area of ​​the array pad 22 on the flexible plate 2. Preferably, the projected area of ​​the support element 5 on the flexible plate 2 is 0.7 to 0.9 times the projected area of ​​the array pad 22 on the flexible plate 2, thereby ensuring that the support element 5 does not undergo plastic deformation during the planting stage and is completely accommodated within the pad coupling range.

[0076] In some embodiments, the height H of the support element 5 is equal to (the ratio of the diameter of the ball pad of the support element 5 to the diameter d of the array pad 22) / (the flatness ratio f of the support element 5).

[0077] Where: ball pad diameter ratio Flatness of support element 5 in its uncompressed and stretched state The flatness ratio of support element 5 is the diameter (maximum diameter value in the horizontal plane) of support element 5 and the height (maximum value in the vertical axis) of support element 5. ,Right now .

[0078] In some embodiments, the height H of the support element 5 is equal to the warpage w of the flexible plate 2 multiplied by the warpage ratio n of the flexible plate 2, where the warpage ratio n of the flexible plate 2 is within a certain range. , , Right now Generally, the warpage can be in the range of 5~15μm.

[0079] The warpage factor of the flexible board 2 is to ensure that, taking the plane where the highest point of the flexible board 2 is located as the base plane, even if the support element 5 is placed on the array element pad 22 in the area with the greatest distance from the base plane (such as near the lowest point of the warped flexible board), the upper end of the support element 5 can still be higher than the base plane by a certain proportion. This ensures that even if the support element 5 is extended and deformed, the extended and deformed support element will still have a part higher than the base plane. The cut is made at the position higher than the base plane to ensure that the transducer stack 1 is cut through without cutting the flexible board 2.

[0080] In some embodiments, the height of the support element 5 is constrained by both the diameter of the array element pad 22 and the warpage of the flexible plate 2, and the specific value range is determined by both of these function ranges. The height range of the support element 5 is as follows: Further , where d represents the diameter of the element pad 22 and w represents the warpage of the flexible board 2.

[0081] In some embodiments, an adhesive 6 is also filled between the flexible plate 2 and the transducer array element 11. The adhesive 6 is composed of an insulating material and is distributed between the support elements 5 for mechanically connecting the flexible plate 2 and the transducer array element 11.

[0082] like Figure 2 As shown, adhesive 6 is filled between the flexible plate 2 and the transducer stack 1 to mechanically connect the flexible plate 2 and the transducer stack 1, so that the two obtain a stable relative positional relationship. Thus, when the transducer stack 1 is cut to obtain the transducer array element 11, the transducer stack 1 can be prevented from moving relative to the flexible plate 2, and the cut transducer array element 11 can be firmly fixed on the surface of the flexible plate 2.

[0083] In some embodiments, the curing temperature of the adhesive 6 is a first temperature, and the support element 5 can stretch and deform in response to pressure at an environment below the first temperature.

[0084] The curing temperature of adhesive 6 is higher than the operating temperature at which positive pressure is applied to transducer stack 1 and flexible plate 2. That is, when positive pressure is applied to transducer stack 1 and flexible plate 2 and support element 5 undergoes plastic deformation, adhesive 6 is in a liquid state and has a certain fluidity. It can automatically flow with the change of the distance between transducer stack 1 and flexible plate 2, filling the gap between transducer stack 1 and flexible plate 2. After the deformation of support element 5 is completed, the temperature is raised to the first temperature (e.g., 60°C). At this time, adhesive 6 is cured and its fluidity disappears, mechanically connecting flexible plate 2 and transducer stack 1.

[0085] This application effectively balances the stability of the electrical coupling and mechanical connection between the flexible plate 2 and the transducer array 11. Figure 1Existing technologies employ direct surface-to-surface connection between flexible plates and conductive layers. In contrast, this application utilizes multiple deformable support elements 5 (similar to deformable support rods). Under positive pressure, each support element deforms according to its contact state (e.g., elastic compression), resulting in more uniform force distribution and reduced localized stress concentration. These deformable support elements absorb energy through elastic / plastic deformation, buffering positive pressure fluctuations or impact loads (e.g., vibration, collisions), reducing instantaneous stress peaks, and protecting the connected transducer stack and flexible plate from damage. Furthermore, deformation releases internal stress, compensating for installation errors caused by uneven contact surfaces (e.g., flexible plates), resulting in greater adaptability to changing operating conditions. Additionally, the deformable support elements 5 introduce a degree of "flexibility" to the connection, facilitating changes in connection shape. Figure 5 Transform into Figure 7 , or connection form by Figure 6 Transform into Figure 8 In some cases, due to the flexible transition of the connection shape, the transducer stack can adapt to the connection and undergo a certain degree of deformation without damaging the transducer stack structure, such as... Figure 9 or Figure 10 As shown. On the other hand, this application sets the deformation of the support element 5 and the curing of the adhesive 6 to be asynchronous, so that the adhesive 6 maintains fluidity during the stage when the support element 5 is compressed and deformed, ensuring that the deformation of the support element 5 is less affected by the adhesive, and also ensuring that the adhesive can fill the gap between the support elements in a timely manner as the support element 5 deforms, ensuring that there is no short circuit connection between the support elements.

[0086] In some embodiments, the multiple transducer array elements 11 are distributed in a one-dimensional linear array, a ring array, a sector array, or a two-dimensional matrix to meet various applicable needs.

[0087] When planting the support element 5, it should be planted according to the arrangement of the transducer array element 11 to ensure that the support element 5 corresponds one-to-one with the transducer array element 11 and the array element pad 22 on the flexible board 2.

[0088] like Figure 3 As shown, the transducer array elements 11 are distributed in a two-dimensional matrix. Therefore, the support elements 5 should also be arranged in a two-dimensional matrix on the surface of the flexible plate 2 during installation. Correspondingly, when the transducer array elements 11 are distributed in a linear pattern, the array element pads 22 and the support elements 5 are also distributed in a linear pattern. Similarly, other distribution methods are similar and will not be listed one by one.

[0089] In addition to the ultrasonic transducers disclosed in the above embodiments, the present invention also provides a method for manufacturing the ultrasonic transducers described above, comprising:

[0090] A conductive coating is applied to the outside of the acoustic components to form a transducer stack 1, and support elements 5 are planted one by one at the positions of the array pads 22 of the flexible board 2.

[0091] The transducer stack 1 is placed on the side of the flexible plate 2 where the support element 5 is planted, and the gap between the transducer stack 1 and the flexible plate 2 is filled with adhesive 6.

[0092] Applying positive pressure causes the support element 5 to deform in order to connect the array pads 22 and the transducer stack 1 respectively, and the adhesive 6 flows along with the deformation of the support element 5.

[0093] Curing adhesive 6;

[0094] The transducer stack 1 is cut to form multiple transducer array elements 11.

[0095] By pre-planting support elements 5 on the surface of the flexible plate 2, when the transducer stack 1 is bonded, the support elements 5 act as conductive materials to conduct the conductive layer of the transducer stack 1 and the array element pads 22 on the flexible plate 2. Furthermore, by applying positive pressure between the transducer stack 1 and the flexible plate 2, the support elements 5 at different positions undergo different degrees of extension and deformation to adapt to the different spacing between the transducer stack 1 and the flexible plate 2, ensuring that the conductive layer and the array element pads 22 at different positions can be coupled by the support elements 5.

[0096] like Figure 4 As shown, by adding support element 5, after the conductive layer of transducer stack 1 is fully connected to the array element pad 22 of flexible plate 2, there is a large gap between transducer stack 1 and flexible plate 2, which is used for the height selection of the cutting blade drop point (the lowest point of the cutting part).

[0097] If so Figure 1 As shown, if no support element 5 is provided between the flexible plate 2 and the transducer stack 1, the upper surface of the flexible plate 2 and the lower surface of the transducer stack 1 will be directly attached. When either of them warps, the contact surface will be non-flat. When the cutting blade feeds along the horizontal path, the flexible plate 2 will inevitably be damaged by cutting or the transducer stack 1 will not be completely cut through, resulting in a short circuit of the transducer element 11.

[0098] Simultaneously, adhesive 6 is filled between the transducer stack 1 and the flexible plate 2. Adhesive 6 flows with the deformation of the support element 5, filling the gap between the transducer stack 1 and the flexible plate 2. After the support element 5 deforms, the adhesive 6 is cured, thus achieving a stable connection between the transducer stack 1 and the flexible plate 2. At this point, cutting the transducer stack 1 yields the transducer array element 11. Correspondingly, each transducer array element 11 is connected to a unique support element 5 and a unique array element pad 22, achieving connection with the corresponding connection port on the flexible plate 2.

[0099] It is worth noting that the adhesive 6 is preferably filled before the positive pressure is applied to the transducer stack 1 and the flexible plate 2, so as to avoid the presence of adhesive voids in some positions due to the deformation of the support element 5, which would cause insufficient insulation. This allows the adhesive 6 to flow with the deformation of the support element 5. Alternatively, the adhesive 6 can be filled after the positive pressure is applied, which can achieve the same effect. However, due to the influence of the flowability of the adhesive 6, the filling difficulty is increased and the filling effect may be affected.

[0100] In some embodiments, before planting the support element 5 at each of the array pads 22 of the flexible board 2, the method further includes:

[0101] On the other side of the flexible board 2, the supporting element 5 is planted, and the flexible board 2 is soldered to the special chip or component using solder.

[0102] Between the planting support elements 5, the flexible plate 2 is pre-bonded to the chip assembly 4 through solder balls 3, so that the flexible plate 2 and the chip assembly 4 have a stable positional relationship. At this time, the warping deformation of the flexible plate 2 caused by the process is not easy to recover, and the warping deformation is fixed by the chip assembly 4. At this time, the support elements 5 can be planted according to the distribution of the array pads 22 after the warping deformation of the flexible plate 2.

[0103] In some embodiments, cutting the transducer stack 1 to form a transducer array 11 includes:

[0104] Control the bottom surface of the cutting blade to move along the Z-axis to the blade landing point A;

[0105] Control the cutting blade to advance along the X-axis or Y-axis to cut the transducer stack 1;

[0106] The height of the cutting point A falls within the height range of the supporting element 5, and the height of the cutting point A is between the bottom surface height of the transducer stack 1 and the top surface height of the flexible plate 2. The height of the cutting point only needs to be higher than the highest point of the flexible plate to avoid damage to the flexible plate; and the cutting point needs to be lower than the lowest point of the transducer stack to ensure that the transducer stack can be completely cut and to avoid short circuits in the transducer array elements.

[0107] It should be noted that without the support element 5, the height difference between the bottom surface of the transducer stack 1 and the top surface of the flexible plate 2 is only a few nanometers. Furthermore, the gap between the bottom surface of the transducer stack 1 and the top surface of the flexible plate 2 is not a horizontal and flat surface. When the cutting blade feeds along a horizontal path, it is easy to cause incomplete cutting through parts of the transducer stack or damage to parts of the flexible plate. However, this application compensates for the warpage by adding the support element and ensures that even the minimum gap between the bottom surface of the transducer stack 1 and the top surface of the flexible plate 2 is greater than 5μm, which meets the accuracy achievable by common cutting blade equipment on the market and ensures that it can be executed.

[0108] like Figures 7-10 When a positive pressure is applied between the transducer stack 1 and the flexible plate 2, the transducer stack 1 is pressed down. During this process, the support element 5 is compressed and undergoes plastic deformation. The deformation of the support element 5 varies at different positions. Moreover, during the process, the transducer stack 1 can maintain the following properties: Figure 8 The original flatness shown also exists, as in the case of... Figure 9 and Figure 10 As shown in the warping deformation, when selecting the cutting point A, the plane M where the lowest point of the transducer stack 1 is located and the plane N where the highest point of the flexible board 2 is located should be determined first. Since there is a support element 5 between plane M and plane N, the height of plane M must be higher than the height of plane N. The cutting point A should be located between plane M and plane N. At this time, it can be ensured that the transducer stack 1 is completely cut through, and the flexible board 2 will not come into contact with the cutting blade and be damaged. Regardless of whether the cutting point and the entry point are directly above the pads of the input and output ports, the pads of the input and output ports and the circuit of the flexible board will not be cut and damaged.

[0109] It should be noted that the support element 5 and the array element pad 22 are both set for the transducer array element. The transducer array element 11 is a separate and independent part retained after the cutting blade divides the transducer stack 1. The corresponding support element 5 and array element pad 22 are not on the cutting blade's feed path. The cutting blade's feed path should be in the gap between the support elements 5. The height of the support element mentioned above and the height of the cutting blade's drop point A (the lowest cutting position of the cutting blade) are only a comparison of height values ​​to illustrate that the lowest cutting height of the cutting blade is within the height range of the support element 5. More preferably, the lowest cutting height of the cutting blade is about 1 / 2 the height of the support element 5 to better ensure that the lowest cutting position of the cutting blade is mainly in the gap between the support elements 5 and cannot reach the surface of the flexible board in the path of cutting the transducer stack.

[0110] In some embodiments, setting the cutting parameters includes at least one of the following:

[0111] The plane where the highest point of the flexible plate 2 is located is the base plane, and the height of the knife drop point A is higher than the height of the base plane of the flexible plate 2;

[0112] The distance between the cutting point A and the edge of the transducer stack 1 is not less than the preset distance L1.

[0113] like Figure 2 As shown, when selecting the blade drop point A, in addition to selecting the height of the blade drop point, the horizontal distance between the blade drop point and the transducer stack 1 is also selected. This ensures that the distance between the blade drop point A and the edge of the transducer stack 1 is not less than a preset distance L1, so that the cutting blade of the disc blade... Figure 4When the cutting blade falls along the path shown, it does not come into contact with the transducer stack 1. After the cutting blade falls to point A, it then performs horizontal feeding to complete the cutting of the transducer stack 1. During the cutting process, there is only horizontal relative movement between the cutting blade and the transducer stack 1, which avoids damage to the transducer array element 11 during the cutting process and ensures the cutting effect.

[0114] At the same time, when setting the preset distance L1, the distance between the input / output port pad 21 and the edge of the transducer stack 1 should be taken into account, so that the tool drop point A avoids the input / output port pad 21 and avoids damage to it.

[0115] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0116] The ultrasonic transducer and manufacturing method provided by this invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make several improvements and modifications to this invention without departing from the principles of this invention, and these improvements and modifications also fall within the protection scope of the claims of this invention.

Claims

1. An ultrasonic transducer, characterized in that, include: A flexible board is used to connect with the chip as a whole, and the surface of the flexible board is provided with multiple array element pads; Multiple transducer array elements, each transducer array element is covered with a conductive layer, and each transducer array element is configured in a one-to-one correspondence with the array element pads. A support element is disposed between the transducer element and the element pad. The support element is made of a conductive plastic material and is capable of stretching and deforming in response to pressure to couple the element pad to the conductive layer of the transducer element.

2. The ultrasonic transducer according to claim 1, characterized in that, The supporting element is an ellipsoidal or spherical geometric shape, and the height of the supporting element is greater than the warpage of the flexible plate.

3. The ultrasonic transducer according to claim 1, characterized in that, The projected area of ​​the support element on the flexible plate is smaller than the projected area of ​​the array element pad on the flexible plate.

4. The ultrasonic transducer according to claim 1, characterized in that, The height range of the support element is: , where d represents the diameter of the element pad and w represents the warpage of the flexible board.

5. The ultrasonic transducer according to claim 1, characterized in that, An adhesive is also filled between the flexible plate and the transducer array element. The adhesive is distributed between the support elements and is used to mechanically connect the flexible plate and the transducer array element.

6. The ultrasonic transducer according to claim 5, characterized in that, The curing temperature of the adhesive is a first temperature, and the support element can stretch and deform in response to pressure at an environment below the first temperature.

7. The ultrasonic transducer according to any one of claims 1-6, characterized in that, The multiple transducer array elements are distributed in a one-dimensional linear array, a ring array, a sector array, or a two-dimensional matrix.

8. A manufacturing method, characterized in that, For manufacturing the ultrasonic transducer according to any one of claims 1-7, comprising: A conductive coating is applied to the outside of the acoustic components to form a transducer stack, and support elements are planted one by one at the array element pads of the flexible board. The transducer stack is positioned on the side of the flexible plate where the support element is grown, and adhesive is filled into the gap between the transducer stack and the flexible plate. Applying positive pressure causes the support element to deform in order to connect the array pads and the transducer stack respectively, and the adhesive flows as the support element deforms; Curing the adhesive; The transducer stack is cut to form multiple transducer array elements.

9. The manufacturing method according to claim 8, characterized in that, Before planting the support elements at the corresponding positions of the array pads on the flexible board, the method further includes: On the other side of the flexible plate used to grow the support element, the flexible plate is soldered to a special chip or component using solder.

10. The manufacturing method according to claim 8, characterized in that, The process of cutting the transducer stack to form multiple transducer array elements includes: Control the bottom surface of the cutting blade to move along the Z-axis to the blade landing point A; Control the cutting blade to advance along the X-axis or Y-axis to cut the transducer stack; The height of the drop point A is within the height range of the support element, and the height of the drop point A is between the bottom surface height of the transducer stack and the top surface height of the flexible plate.

11. The manufacturing method according to claim 10, characterized in that, Setting cutting parameters includes at least one of the following: The plane containing the highest point of the flexible plate is the base plane, and the height of the knife drop point A is higher than the height of the base plane of the flexible plate; The distance between the cutting point A and the edge of the transducer stack is not less than a preset distance L1.

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