An ultrasonic transducer assembly with x-direction motion and method of x-direction motion thereof

Abstract

The application discloses a kind of ultrasonic transducer assembly with X direction movement and its X direction movement method, transducer assembly includes: fixed seat;Head transducer group, setting in fixed seat end;Piezoelectric stack, setting in the two sides of fixed seat, including multiple by epoxy resin bonding and alternating arrangement piezoelectric ceramic thin layer and electrode layer, multiple piezoelectric ceramic thin layer positive and negative pole series connection;The present application is designed in the two sides of fixed seat piezoelectric stack, make the grinding action of ultrasonic transducer assembly in X direction by piezoelectric stack, displacement precision is high, work stroke is short, response speed is fast, can shorten welding time and improve UPH;While in the movement process, can improve spherical and welding fish tail problem, improve welding strength, improve welding quality, reduce error frequency;And can be applied in material substrate thinner material, with X direction movement ultrasonic transducer can use lower welding power to complete ball mounting welding line, can reduce the risk of material surface fragmentation in welding process.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of semiconductor packaging, in particular to an ultrasonic transducer assembly with X-direction motion and an X-direction motion method thereof. BACKGROUND

[0002] The wire bonding machine includes a gold wire machine, an aluminum wire machine, etc., which is used to realize the surface welding of different media and is a physical change process.

[0003] When the gold ball wire bonding machine is working, a specific frequency and amplitude of mechanical vibration are needed to complete the wire bonding operation. After the transducer receives the electrical signal, it uses the piezoelectric effect or magnetostrictive effect principle to convert electrical energy into mechanical energy, generates high-frequency mechanical vibration, and transmits it to the wedge and other welding tools, so that the wedge produces high-frequency vibration.

[0004] During the welding process, the wedge and other welding tools produce high-frequency vibration to promote the welding wire to rub the welding surface. Under the combined action of pressure and vibration, the welding wire plastically deforms, removes the metal surface oxide layer and impurities in the contact area, ensures good contact at the welding site, and causes atomic diffusion to form a metal bonding layer, ensuring firm welding.

[0005] The ultrasonic transducer structure of the wire bonding machine on the market at present mainly consists of a piezoelectric ceramic stack, a transducer main body, a fixed seat, etc. Its structure determines that the working direction is mainly the front and back vibration in the Y direction, as shown in Figure 1 . SUMMARY

[0006] The present application provides an ultrasonic transducer assembly with X-direction motion and an X-direction motion method thereof to solve the above problems existing in the prior art.

[0007] Technical scheme: An ultrasonic transducer assembly with X-direction motion, comprising:

[0008] a fixed seat;

[0009] a head transducer group arranged at the end of the fixed seat;

[0010] a piezoelectric stack arranged on both sides of the fixed seat, comprising a plurality of piezoelectric ceramic thin layers and electrode layers which are alternately arranged and bonded by epoxy resin, and the positive and negative poles of the plurality of piezoelectric ceramic thin layers are connected in series;

[0011] The piezoelectric stack is designed on both sides of the fixed seat, so that the grinding action of the ultrasonic transducer assembly in the X direction is performed by the piezoelectric stack. The displacement precision is high, the working stroke is short, the response speed is fast, the welding time can be shortened, and the UPH can be improved.

[0012] At the same time, during the motion process, the problems of spherical and welding fish tail can be improved, the welding strength can be improved, the welding quality can be improved, and the error frequency can be reduced.

[0013] And can be applied to the material substrate is thinner material, with X direction movement of ultrasonic transducer can be used to complete the ball welding with lower welding power, can reduce the risk of material surface fragmentation in the welding process.

[0014] In further embodiments, the piezoelectric ceramic thin layer and the electrode layer alternately arranged both ends are provided with a zirconium oxide sheet;

[0015] The zirconium oxide sheet and the piezoelectric ceramic thin layer and the electrode layer alternately arranged both ends are bonded by epoxy resin;

[0016] The zirconium oxide sheet is arranged at the left and right ends of the outermost layer of the piezoelectric ceramic thin layer and the electrode layer alternately arranged;

[0017] The piezoelectric stack is integrated by laminating the piezoelectric ceramic thin layer and the electrode layer alternately arranged by epoxy resin bonding process, then the positive and negative electrodes of each piezoelectric ceramic thin layer are connected by soldering and solder bridge process according to the electric field polarity of the piezoelectric ceramic thin layer, forming the positive electrode of the piezoelectric stack and the negative electrode of the piezoelectric stack; Finally, the zirconium oxide sheet located at the left and right ends of the outermost layer is bonded by epoxy resin, forming an actuator with three-dimensional electrode structure. Under the premise of maintaining millisecond dynamic response, the small displacement of each layer of ceramic is superimposed by this series of stacked structure, so as to expand the single layer displacement to nearly 100 microns output. This structure realizes the balance of low driving voltage and high mechanical gain at the same time, and the application of epoxy bonding layer not only ensures the electrical insulation between layers, but also maintains the mechanical stability of the whole;

[0018] The piezoelectric stack will produce different degrees of length change according to the input of various electrical signals.

[0019] In further embodiments, the fixed seat is in the shape of an I-beam, and the piezoelectric stack is arranged in the notch on both sides of the I-beam-shaped fixed seat.

[0020] In further embodiments, a first deformation groove is formed on the vertical section of the I-beam-shaped fixed seat.

[0021] In further embodiments, the end of the fixed seat is provided with a pre-tightening screw abutting against the piezoelectric stack, and the piezoelectric stack is installed on both sides of the fixed seat.

[0022] The pre-tightening screw can adjust the pre-tightening degree of the piezoelectric stack on both sides, affecting the swing amplitude of the fixed seat during operation; the head transducer group is installed on the front of the fixed seat by installing a fixed screw, and finally assembled into an ultrasonic transducer assembly with X direction movement;

[0023] The action of the ultrasonic transducer assembly with X-direction movement in the X direction is performed by the piezoelectric stacks on both sides of the fixed seat, and by controlling the working time, power amplitude and working frequency of the piezoelectric stacks on both sides, the piezoelectric stacks are alternately stretched and contracted to realize the rapid and high-frequency reciprocating swing of the ultrasonic transducer assembly with X-direction movement in the X direction.

[0024] In further embodiments, the head transducer group comprises:

[0025] A transducer body is connected with the fixed seat, and a ceramic group placing groove is formed in the transducer body, and second deformation grooves are formed on both sides of the ceramic group placing groove;

[0026] A piezoelectric ceramic group is arranged in the ceramic group placing groove;

[0027] A split knife ceramic nozzle is installed on the front of the transducer body;

[0028] The transducer body is connected with the fixed seat through a mounting fixed screw;

[0029] The head transducer group functions to convert high-frequency electrical signals into high-frequency mechanical vibrations through the inverse piezoelectric effect in the gold wire welding process, and the ultrasonic welding is realized by transmitting the high-frequency mechanical vibrations to the gold wire through the transducer body and the split knife ceramic nozzle;

[0030] An X-direction movement method of an ultrasonic transducer assembly with X-direction movement comprises the following steps:

[0031] Step 1: when the voltage of the left piezoelectric stack is reduced, the left piezoelectric stack is shortened, the voltage of the right piezoelectric stack is increased, the right piezoelectric stack is elongated, the structure in the middle of the fixed seat is deformed to deflect to the left side, the head transducer group is deflected to the left side, and the movement is completed;

[0032] Step 2: when the voltage of the left piezoelectric stack is increased, the left piezoelectric stack is elongated, the voltage of the right piezoelectric stack is reduced, the right piezoelectric stack is shortened, the structure in the middle of the fixed seat is deformed to deflect to the right side, the head transducer group is deflected to the right side, and the movement is completed;

[0033] Steps 1 and 2 are repeatedly performed, and the X-direction left-right reciprocating movement of the ultrasonic transducer assembly is realized.

[0034] Beneficial effects: the application discloses an ultrasonic transducer assembly with X-direction movement, the piezoelectric stacks are designed on both sides of the fixed seat, the grinding action of the ultrasonic transducer assembly in the X direction is performed by the piezoelectric stacks, the displacement precision is high, the working stroke is short, the response speed is fast, the welding time can be shortened, and the UPH is improved;

[0035] Meanwhile, in the movement process, the problems of the spherical shape and the welded fish tail can be improved, the welding strength is improved, the welding quality is improved, and the error frequency is reduced.

[0036] And can be applied to the material substrate is thinner material, with X direction movement of ultrasonic transducer can be used to complete the ball welding with lower welding power, can reduce the risk of material surface fragmentation in the welding process. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 is the prior art schematic diagram.

[0038] Figure 2 is the structure schematic diagram of the present application.

[0039] Figure 3 is the piezoelectric stack structure schematic diagram of the present application.

[0040] Figure 4 is the right swing schematic diagram of the present application.

[0041] Figure 5 is the left swing schematic diagram of the present application.

[0042] The reference signs are:

[0043] 1, head transducer group; 2, fixed seat;

[0044] 3, piezoelectric stack; 301, piezoelectric ceramic thin layer; 302, electrode layer; 303, zirconium oxide sheet; 304, piezoelectric stack positive; 305, piezoelectric stack negative;

[0045] 4, pre-tightening screw; 5, first deformation groove; 6, second deformation groove. DETAILED DESCRIPTION

[0046] The present application relates to a kind of ultrasonic transducer assembly with X direction movement and its X direction movement method, since the ultrasonic transducer structure of welding machine in current market is mainly composed of piezoelectric ceramic stack, transducer main body, fixed seat and the like, its structure determines that its working direction is mainly Y direction front-back vibration (such as Figure 1 As shown), the following problems can appear:

[0047] 1, ultrasonic transducer mainly works in Y direction, and working mode is single, and solder ball shape is easy to be oval;

[0048] 2, the grinding action in X direction in welding process needs to be matched with X platform to carry out small and high frequency reciprocating motion, and the required time is long;

[0049] 3, X motor in matched platform needs to bear short-time large load, and motor heat quantity is larger, when X motor drives bonding head to execute grinding, it generates greater noise and vibration to equipment as a whole;

[0050] 4. In scenarios where the substrate material is relatively thin, welding of ordinary ultrasonic transducers requires high welding power, but this can easily cause the material surface to crack. Using low power can cause the solder balls to peel off, resulting in material damage.

[0051] This application designs piezoelectric stacks on both sides of the fixed base, and performs the grinding action of the ultrasonic transducer assembly in the X direction through the piezoelectric stacks. It has high displacement accuracy, short working stroke and fast response speed, which can shorten the welding time and improve UPH.

[0052] This execution method can improve the problems of spherical shape and welded fish tail, increase welding strength, improve welding quality, and reduce error frequency.

[0053] By using a series-layered structure (a piezoelectric ceramic thin layer and an electrode layer bonded together with epoxy resin and arranged in an alternating pattern, with the positive and negative electrodes of multiple piezoelectric ceramic thin layers connected in series), the minute displacements of each ceramic layer are superimposed, thereby extending the displacement of a single layer to an overall output of nearly 100 micrometers. This structure simultaneously achieves a balance between low driving voltage and high mechanical gain, and is applicable to materials with thin substrates. The ultrasonic transducer with X-axis motion can complete wire bonding with lower welding power, reducing the risk of material surface breakage during welding. The following detailed explanation is provided through specific implementation methods.

[0054] An ultrasonic transducer assembly with X-axis motion is shown in the attached figure. Figure 2 As shown, it includes:

[0055] The fixed base 2, the piezoelectric stacks 3 arranged on both sides of the fixed base 2, and the ring energy group connected to the fixed base 2;

[0056] The fixing base 2 is I-shaped, and the piezoelectric stack 3 is disposed in the notches on both sides of the I-shaped fixing base 2;

[0057] The head transducer assembly 1 includes:

[0058] The transducer body is connected to the fixed base 2. A ceramic assembly placement groove is opened on the transducer body. Second deformation grooves 6 are opened on both sides of the ceramic assembly placement groove. The second deformation grooves 6 are opened to facilitate the expansion and contraction deformation of the transducer body.

[0059] A piezoelectric ceramic assembly is disposed within the ceramic assembly placement slot;

[0060] A ceramic nozzle with a split blade is installed at the front of the transducer body;

[0061] The transducer body is connected to the mounting base 2 by mounting screws;

[0062] The function of the head transducer group 1 is to convert high-frequency electrical signals into high-frequency mechanical vibrations through the inverse piezoelectric effect during the gold wire bonding process, and transmit them to the gold wire through the transducer body and the cleaver ceramic nozzle to achieve ultrasonic welding.

[0063] As attached Figure 3 As shown, the piezoelectric stack 3 includes multiple piezoelectric ceramic thin layers 301 and electrode layers 302 bonded together with epoxy resin and arranged alternately, with the positive and negative electrodes of the multiple piezoelectric ceramic thin layers 301 connected in series.

[0064] By designing piezoelectric stacks 3 on both sides of the fixed base 2, the grinding action of the ultrasonic transducer assembly in the X direction is performed by the piezoelectric stacks 3, which has high displacement accuracy, short working stroke, and fast response speed, which can shorten the welding time and increase UPH.

[0065] At the same time, during the process, it can improve the spherical shape and welding fish tail problems, increase welding strength, improve welding quality, and reduce error frequency;

[0066] Furthermore, it can be applied to materials with thin substrates. Ultrasonic transducers with X-axis motion can complete wire bonding with lower welding power, which can reduce the risk of material surface cracking during the welding process.

[0067] Zirconia sheets 303 are provided at both ends of the multiple alternately arranged piezoelectric ceramic thin layers 301 and electrode layers 302;

[0068] The zirconium oxide sheet 303 is bonded to both ends of a plurality of alternately arranged piezoelectric ceramic thin layers 301 and electrode layers 302 by epoxy resin.

[0069] Zirconia sheet 303 is disposed at the left and right ends of the outermost layer of multiple alternating piezoelectric ceramic thin layers 301 and electrode layers 302.

[0070] The piezoelectric stack 3 is integrated by first laminating multiple piezoelectric ceramic thin layers 301 with alternating electrode layers 302 using an epoxy resin bonding process. Then, based on the electric field polarity of the piezoelectric ceramic thin layers 301, the positive and negative electrodes of each piezoelectric ceramic thin layer 301 are welded together using solder and solder bridging processes to form a piezoelectric stack positive electrode 304 and a piezoelectric stack negative electrode 305. Finally, the outermost zirconium oxide sheets 303 located at the left and right ends are bonded with epoxy resin to form an actuator with a three-dimensional electrode structure, such as... Figure 3 As shown. While maintaining millisecond-level dynamic response, this series-layered structure enables the small displacements of each ceramic layer to have a superposition effect, thereby extending the displacement of a single layer to an overall output of nearly 100 micrometers. This structure simultaneously achieves a balance between low driving voltage and high mechanical gain, and the application of epoxy bonding layer ensures both interlayer electrical insulation and overall mechanical stability.

[0071] The piezoelectric stack 3 will produce different degrees of length changes according to the input of various electrical signals;

[0072] The first deformation groove 5 is arranged on the vertical section of the fixed seat 2, which facilitates the left and right swing deformation of the fixed seat 2, thereby adapting to the swing.

[0073] The fixed seat 2 is provided with a pre-tightening screw 4 abutting against the piezoelectric stack 3, and the piezoelectric stack 3 is installed on both sides of the fixed seat 2.

[0074] The pre-tightening screw 4 can adjust the pre-tightening degree of the piezoelectric stack 3 on both sides, thereby affecting the swing amplitude of the fixed seat 2 during work.

[0075] The X-direction movement of the ultrasonic transducer assembly with X-direction movement is performed by the piezoelectric stack 3 on both sides of the fixed seat 2, and the working time, power amplitude and working frequency of the piezoelectric stack 3 on both sides are controlled to cooperate with each other to realize the rapid and high-frequency reciprocating swing of the ultrasonic transducer assembly with X-direction movement in the X-direction.

[0076] An X-direction movement method of an ultrasonic transducer assembly with X-direction movement, comprising:

[0077] Step 1: When the voltage of the left piezoelectric stack 3 decreases, the left piezoelectric stack 3 shortens, the voltage of the right piezoelectric stack 3 increases, and the right piezoelectric stack 3 elongates, so that the structure in the middle of the fixed seat 2 is deformed to the left side, and the head transducer group 1 is driven to the left side, and the movement is completed.

[0078] Step 2: When the voltage of the left piezoelectric stack 3 increases, the left piezoelectric stack 3 elongates, the voltage of the right piezoelectric stack 3 decreases, and the right piezoelectric stack 3 shortens, so that the structure in the middle of the fixed seat 2 is deformed to the right side, and the head transducer group 1 is driven to the right side, and the movement is completed.

[0079] Repeating steps 1 and 2 can realize the X-direction reciprocating movement of the ultrasonic transducer assembly.

[0080] Working principle: as shown in the accompanying Figure 5 When the voltage of the left piezoelectric stack 3 decreases, the left piezoelectric stack 3 shortens, the voltage of the right piezoelectric stack 3 increases, and the right piezoelectric stack 3 elongates, so that the structure in the middle of the fixed seat 2 is deformed to the left side, and the head transducer group 1 is driven to the left side, and the movement is completed.

[0081] As shown in the accompanying Figure 4As shown, when the voltage of the left piezoelectric stack 3 is raised, the left piezoelectric stack 3 is elongated, the voltage of the right piezoelectric stack 3 is lowered, the right piezoelectric stack 3 is shortened, the structure in the middle of the fixed seat 2 is deformed to deflect to the right side, the head transducer group 1 is driven to deflect to the right side, and the movement is completed.

[0082] The preferred specific embodiments of the present application are described in detail above in combination with the drawings, but the present application is not limited to the specific details in the above specific embodiments. Within the technical concept scope of the present application, the technical solutions of the present application can be variously transformed, and these equivalent transformations all belong to the protection scope of the present application.

Claims

1. An X-motion method for an ultrasonic transducer assembly with X-motion, characterized by, The application relates to an ultrasonic transducer assembly. Step 1: when the voltage of the left piezoelectric stack (3) is reduced, the left piezoelectric stack (3) is shortened, the voltage of the right piezoelectric stack (3) is increased, the right piezoelectric stack (3) is elongated, the structure in the middle of the fixed seat (2) is deformed to deflect to the left, the head transducer group (1) is driven to deflect to the left, and movement is completed; Step 2: when the voltage of the left piezoelectric stack (3) is increased, the left piezoelectric stack (3) is elongated, the voltage of the right piezoelectric stack (3) is reduced, the right piezoelectric stack (3) is shortened, the structure in the middle of the fixed seat (2) is deformed to deflect to the right, and the head transducer group (1) is driven to deflect to the right; Steps 1 and 2 are repeatedly executed, and X-direction left-right reciprocating movement of the ultrasonic transducer assembly can be realized. The application is based on the following device: a fixed seat (2); a head transducer group (1) arranged at the end of the fixed seat (2); a piezoelectric stack (3) arranged on both sides of the fixed seat (2) and comprising a plurality of piezoelectric ceramic thin layers (301) and electrode layers (302) which are alternately arranged and bonded by epoxy resin, and the positive and negative poles of the plurality of piezoelectric ceramic thin layers (301) are connected in series; a plurality of zirconia sheets (303) are arranged at both ends of the alternately arranged piezoelectric ceramic thin layers (301) and electrode layers (302); the zirconia sheets (303) and the alternately arranged piezoelectric ceramic thin layers (301) and electrode layers (302) are bonded by epoxy resin at both ends; the fixed seat (2) is in the shape of an I-beam, and the piezoelectric stack (3) is arranged in the notches on both sides of the I-beam-shaped fixed seat (2).

2. An X-motion method for an X-motion ultrasonic transducer assembly according to claim 1, characterized by: A first deformation groove (5) is formed in the vertical section of the I-beam-shaped fixed seat (2).

3. The method of claim 1, wherein: the X-direction motion of the ultrasonic transducer assembly is in an X-direction that is perpendicular to the Y-direction of the ultrasonic transducer assembly. A pre-tightening screw (4) abutting against the piezoelectric stack (3) is arranged at the end of the fixed seat (2) to mount the piezoelectric stack (3) on both sides of the fixed seat (2).

4. The method of claim 1, wherein the X-motion of the ultrasonic transducer assembly is in the X direction. The head transducer group (1) comprises: a transducer body connected with the fixed seat (2), a ceramic group placing groove is formed in the transducer body, and a second deformation groove (6) is formed at the two sides of the ceramic group placing groove; a piezoelectric ceramic group arranged in the ceramic group placing groove; a cleaver ceramic nozzle installed at the front of the transducer body.

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