Design Of Horn Research Articles

Fabrication of through alumina vias (TAV) by ultrasonic micromachining for advanced packaging applications

This article presents the fabrication of a high aspect ratio through alumina-vias (TAV) by combining ultrasonic micromachining (USM), electroless plating, and copper electrodeposition. Various horn designs, i.e., tapered, stepped, exponential, and hybrid horns, were analyzed to achieve a uniform longitudinal vibration in a 6 × 6 multi-tip tool assembly. The modal analysis determined the horn length, and harmonic analysis provided the stress distribution and vibrational amplitude. The tapered horn design was selected for its superior vibration amplification and reduced stresses. Finite element modeling predicted the geometric profiles of the microvias at various USM parameters. Experimental validation showed less than 5 % error in the depths of the microvias. Using the optimized USM parameters, a 6 × 6 array of blind and through-holes was created in a 3 mm thick alumina substrate with an average feed rate of 180 μm/min. The average tool wear was observed to be 0.5 mm when drilling through 3 mm thick alumina. Electroless deposition created a ∼100 nm seed layer on the alumina substrate and achieved good adhesion with via sidewalls. The through-holes were partially filled with a 60 μm thick copper layer by electrodeposition to create through-alumina vias (TAV) that can be used as 3D interconnects in the packaging of high-power electronics.

Longitudinal-Torsional Frequency Coupling Design of Novel Ultrasonic Horns for Giant Magnetostrictive Transducers.

The use of advanced brittle composites in engineering systems has necessitated robotic rotary ultrasonic machining to attain high precision with minimal machining defects such as delamination, burrs, and cracks. Longitudinal-torsional coupled (LTC) vibrations are created by introducing helical slots to a horn's profile to enhance the quality of ultrasonic machining. In this investigative research, modified ultrasonic horns were designed for a giant magnetostrictive transducer by generating helical slots in catenoidal and cubic polynomial profiles to attain a high amplitude ratio (TA/LA) and low stress concentrations. Novel ultrasonic horns with a giant magnetostrictive transducer were modelled to compute impedances and harmonic excitation responses. A structural dynamic analysis was conducted to investigate the effect of the location, width, depth and angle of helical slots on the Eigenfrequencies, torsional vibration amplitude, longitudinal vibration amplitude, stresses and amplitude ratio in novel LTC ultrasonic horns for different materials using the finite element method (FEM) based on the block Lanczos and full-solution methods. The newly designed horns achieved a higher amplitude ratio and lower stresses in comparison to the Bezier and industrial stepped LTC horns with the same length, end diameters and operating conditions. The novel cubic polynomial LTC ultrasonic horn was found superior to its catenoidal counterpart as a result of an 8.45% higher amplitude ratio. However, the catenoidal LTC ultrasonic horn exhibited 1.87% lower stress levels. The position of the helical slots was found to have the most significant influence on the vibration characteristics of LTC ultrasonic horns followed by the width, depth and angle. This high amplitude ratio will contribute to the improved vibration characteristics that will help realize good surface morphology when machining advanced materials.

Directivity of horns mounted in finite enclosures: A multimodal formulation.

The beamwidth is a primary directivity metric for the design of a constant directivity horn. To date, investigations on this property have predominantly been restricted to the half-space radiation or idealized geometries. This paper examines the beamwidth behavior of an axisymmetric horn mounted in a finite cylindrical enclosure by proposing an elegant multimodal solution to the far-field directivity pattern. The variation of beamwidth is examined for the frequency, dimensions of the enclosure, and shape of the horn. At low frequencies, a fitted model is proposed to precisely depict the intrinsic beam narrowing governed by the enclosure diffraction. The asymptotic behavior of the beamwidth is explored as the flange width increases. In the high-frequency range, the horn profile is a determinant of the directivity characteristics. We report the possibility of extending the bandwidth of a constant directivity horn by leveraging the enclosure diffraction effects. The proposed analytical method is highly accurate and much faster than the finite element method for wideband analysis. It allows for an arbitrary velocity distribution at the mouth of the horn and incorporates idealized flange configurations such as an infinite baffle, a zero-thickness closed baffle, and an infinitely long enclosure as limit cases.

Multimodal-based shape optimization of a rectangular horn mounted in an enclosure for optimum impedance matching

This study presents a multimodal-based method to optimize the boundary shape of a rectangular horn for optimum impedance matching, assuming that the horn is mounted in an enclosure to adapt to practical applications. An infinite rectangular waveguide with a perfectly matched layer is introduced to solve the multimodal radiation impedances of the horn. The throat impedance of the horn is then calculated using the mode matching method. The optimum impedance matching properties over a wide frequency range are obtained by performing gradient-based shape optimization. The results show that the choice of target frequency band can significantly affect the optimization results. The numerical model is verified by the finite element method. The impedance matching performance of an optimal horn design is also experimentally validated.

Design and Analysis of Acoustic Horn for Assistance in Die-Sinking EDM

Many industrial applications and production technologies are based on the application of ultrasound. In many cases, the phenomenon of ultrasound is also applied in the technological processing of the machining of materials. The main element of equipment that uses the effect of ultrasound for machining is the ultrasonic horn. It is also called a sonotrode. The performance of ultrasonic machining technologies depends on the properly designed sonotrode shape. The dependence of fundamental modal properties (natural frequencies, mode shapes) of various sonotrode shapes for various geometrical parameters is analyzed. Modal analysis of the models is determined by the numerical simulation using the finite element method (FEM) design procedure. In ultrasonic machining, the ultrasonic horn plays a vital part in the high-energy machining process. Electric discharge machining (EDM) is used to achieve high processing quality but the machining efficiency is low. The new (EDM+USM) is used for high machining efficiency. The acoustic analysis of the ultrasonically vibrating tool is done with the assistance of the finite element method (FEM) so that it can be used for EDM applications. Key Words: Modal analysis, Ultrasonic horn, Numerical analysis, efficiency of machining, acoustic analysis.

Design of Pyramidal Horn with Arbitrary E/H Plane Half-Power Beamwidth

Design of Pyramidal Horn with Arbitrary E/H Plane Half-Power Beamwidth

An E‐plane horn antenna fed with E‐plane Tee junction conceptualized by SIW technology

AbstractA novel E‐plane horn antenna fed with E‐plane Tee junction, conceptualized using the substrateintegrated waveguide (SIW) technology is introduced and investigated. Conventional SIW‐inspired horn designs are mostly limited to H‐plane sectoral horns, portraying confined radiation along the H‐plane while unconfined, fan‐beam‐shaped radiation along the principal E‐plane. Such radiation characteristics restrict its usage to designs requiring an electric field parallel to the structure and ultimately narrow confined radiation along the principal E‐plane of the embodiment. The proposed design provides a glue‐less solution to designing an E‐plane horn fed by an E‐plane Tee junction, both conceptualized by the SIW technology, having relative ease of fabrication on dual copper clad Printed Circuit Boards. Such a design operates from 17.15 to 18.8 GHz (~9.2% operating bandwidth) with a realized gain greater than 10.5 dBi, making it suitable for applications requiring light‐weighted high‐gain E‐plane sectoral horn antennas.

Vibration Analysis and Shape Design of Half-wave Horn for Improving Welding Strength and Amplitude Uniformity in Ultrasonic Metal Welding

Vibration Analysis and Shape Design of Half-wave Horn for Improving Welding Strength and Amplitude Uniformity in Ultrasonic Metal Welding

Understanding the ultrasound field of high viscosity mixtures: Experimental and numerical investigation of a lab scale batch reactor

In this work, mixtures of increasing viscosity (from 0.9 to ≈720 mPas) are sonicated directly using an ultrasonic horn at 30 kHz to investigate the effect of viscosity on the ultrasound field both from an experimental and numerical point of view. The viscosity of the mixtures is modified by preparing water-polyethylene glycol solutions. The impact of the higher viscosity on the acoustic pressure distribution is studied qualitatively and semi-quantitatively using sonochemiluminescence. The velocity of light scattering particles added in the mixtures is also explored to quantify acoustic streaming effects using Particle Image Velocimetry (PIV). A numerical model is developed that is able to predict cavitationally active zones accounting for both thermoviscous and cavitation based attenuation. The results show that two cavitation zones exist: one directly under the horn tip and one around the part of the horn body that is immersed in the liquid. The erosion patterns on aluminum foil confirm the existence of both zones. The intensity of the cavitationally active zones decreases considerably with increasing viscosity of the solutions. A similar reduction trend is observed for the velocity of the particles contained in the jet directly under the tip of the horn. Less erratic flow patterns relate to the high viscosity mixtures tested. Finally, two numerical models were made combining different boundary conditions related to the ultrasonic horn. Only the model that includes the radial horn movements is able to qualitatively predict well the location of the cavitation zones and the decrease of the zones intensity, for the highest viscosities studied. The current findings should be taken into consideration in the design and modelling phase of horn based sonochemical reactors.

Efficient multimodal-based shape optimization of acoustic horns with application to subwavelength perfect transmission

This paper presents an efficient multimodal-based shape optimization method for maximizing sound radiation from open-ended acoustic horns. The proposed method tightly integrates the improved multimodal admittance method with interpolation-based geometry parameterization to allow flexible design degrees of freedom, with computational cost for gradient evaluation nearly independent of the number of design variables. We demonstrate that our method outperforms an existing discrete-model-based approach in solving typical narrowband and wideband horn design problems, offering increased efficiency and flexibility. For the first time, we achieve novel resonator-like waveguide designs with subwavelength perfect transmission well below the cut-off frequency of classical horns by performing shape optimization. The optimal waveguides exhibit single to multiple transmission peaks or bandpass characteristics. We validate the designs numerically and experimentally and demonstrate that the perfect transmission is related to the excitation of the acoustic resonant mode. Our method has potential applications in the design of compact high-output subwoofers, anechoic duct terminations, and acoustic filters.

Review on design of hybrid longitudinal-torsional ultrasonic vibration horn for rotary ultrasonic machining (RUM) processes

Longitudinal-torsional (L-T) vibration machining process in rotary ultrasonic machining (RUM) technologies has been considered one of the most promising method in order to cope the machining problems of various difficult-to-machine materials (composites, metallic alloys, abrasives, ceramics and glass). However, design complexity of the L-T machining systems keeps it limited for commercial applications. Hybrid L-T horn is the key component to achieve the efficient performance of RUM systems. Design of hybrid L-T horn is highly intricate due to slots geometry, position, and number of slots. At present, there is no study available in the literature specifically focused on the design and implementation of hybrid L-T horn. Therefore, this study systematically describes literature review on the design, simulations and implementation of hybrid L-T vibration horn in RUM applications of difficult-to-machine materials. Furthermore, the present research reveals the critical design parameters of hybrid L-T horn such as incident angle 47.6° gives better surface quality of the machined hole compared to 67.2° at designed resonant frequency 35 kHz.

Design of Hollow Horn Based on Four-terminal Network Method

When designing the horn of the ultrasonic transducer for rotary machining, the traditional analytical method cannot consider the complex assembly cross-section of the horn, resulting in a large final simulation error and design error. At the same time, when the design diameter of the transducer is too large, the size of the back mass obtained by the traditional analytical method is too thin. This paper combines the four terminal network method and the finite element method, selects the sandwich piezoelectric transducer, takes the ER spring chuck commonly used in rotary machining as an example, derives the transmission matrix corresponding to the geometric cross-section shape, and then uses the four-terminal network method and the traditional analytical method to design two sets of stepped ultrasonic transducers with the design frequency of 22 kHz for analysis and comparison. Finally, through the analysis, it is verified that the ultrasonic transducer designed by the four-terminal network method has a performance closer to the theoretical design.

Design optimization of block horn for ultrasonic joining application using RSM–FEA–GA integration approach

This study investigates the design optimization of block horn used in ultrasonic insertion application. Ultrasonic insertion is the process of joining a metal insert with thermoplastic component. As the performance of ultrasonically produced joint depends upon the uniformity of amplitude of vibration generated by horn, the uniformity of displacement amplitude can be improved by optimizing the block horn design. The horn is computationally designed and acoustically analysed by integrating finite element analysis (FEA) with response surface methodology (RSM). The polynomial model for displacement amplitude is developed using RSM. Further, the design of horn is optimized to improve the displacement amplitude by coupling the developed polynomial model with genetic algorithm (GA) as fitness function. The optimized design is acoustically analysed, the results show that the optimal design yields maximum displacement amplitude of 29.57 µm, and the maximum stress induced in the optimal design is 16.3 MPa, which is much lower than fatigue strength of horn material. As the heat developed at joint is quality indicator, the temperature obtained at joint is measured using data acquisition system (DAQ). The measured temperature is 138°C, which correlates well with displacement amplitude developed by optimal design of block horn. The results of this study revealed that the proposed RSM–FEA–GA integration approach managed to find the optimal combination of design variables, which yields maximum displacement amplitude and results good joint performance.

Design of an E-sectoral horn based on PRGW technology for 5G applications

AbstractE-plane sectoral horn antenna based on printed ridge gap waveguide (PRGW) technology is designed for 5G applications. It is implemented on the top plate of the PRGW structure to avoid the losses and dispersion associated with conventional feeding mechanisms. The quasi-transverse electromagneticPRGW-based antenna is excited through a planar microstrip transition. First, the single horn antenna element is introduced with the microstrip feeding section. It shows an impedance bandwidth of fractional bandwidth 26% from 45.7 to 55.4 GHz with the realized gain of 12.7 dBi and radiation efficiency of 90%. In order to maximize the realized gain, a four-element linear horn array is introduced. The same impedance bandwidth is maintained with the array having a gain of 18.6 dBi from 45.7 to 55.4 GHz. The overall antenna array performance in the entire operating frequency range is stable with a radiation efficiency around 85%. Three matching sections are implemented to achieve better impedance matching. One is used to match the horn with the feeding aperture via the PRGW line. Another section is designed to match microstrip transition with PRGW ridge. Finally, two-stage quarter wavelength transformers are required to match the power divider with the array feeding network. A prototype of single-element horn antenna was fabricated to verify the concept of the design. Simulated and measured results show that the proposed antenna can operate in the frequency band of 45–55 GHz with good agreement of radiation performance. Moreover, the proposed designs are implemented and simulated using two microwave simulation tools (CST and HFSS) to verify the radiation performance, which exhibits good agreement. The design of an E-sectoral horn antenna and its array with high gain based on PRGW is demonstrated for the first time which is considered a novel issue. It can be integrated with other passive and active elements in communication systems. Thus, it can be a valuable component in 5G communication due to its high gain, compact size and ultra-wide band.

Optimal Design of Ultrasonic Horn for Ultrasonic Drilling Processing of Ceramic Material

Optimal Design of Ultrasonic Horn for Ultrasonic Drilling Processing of Ceramic Material

Design and Analysis of Hollow Catenoidal Horn Profile for Ultrasonic Machining of Composite Materials

The composite materials Si/AlC, crystal quartz, and ceramic glass are becoming an important part of the present society in many engineering and non-engineering fields. Conventional methods available for machining these materials have many flaws due to which their application on large scale is restricted. A non-conventional process known as ultrasonic machining (USM), can be implemented for machining of these materials effectively. Anyhow machining efficiency of USM greatly depends upon its horn design and therefore in the present study a horn based on a catenoidal profile with aluminum and titanium material for USM was designed and developed by using solid works and ANSYS. Modal and harmonic analysis was done on the horn for computation of various parameters of interest such as resonant frequency, amplitude vibration and equivalent stresses. After the computation of the results, they were analyzed and compared with those available in the literature in terms of stresses and magnification factor for their validation comparison with literature, it was found that an aluminum catenoidal horn shows higher magnification with the least stress magnitude as compared to horns avail-able in the literature and hence can be used in USM as a replacement for existing horns.

A new design of wide blade ultrasonic horns using Non-Uniform Rational B-Spline shaped slots

In the present study, for the first time, the shapes of slots of wide blade horns are optimized using Non-Uniform Rational B-Spline (NURBS) curves. Here, two 20 kHz horns with different gain ratios (2.5 and 3.5) are designed. The amplitude uniformity and maximum stress of horns are regarded to design. Some control points are used to define the shape of slots, and the position and weight of these points are determined. The genetic algorithm with a link to Abaqus is applied for the optimization process. The simulation results show that the designed horns have high amplitude uniformity equal to 0.978, 0.965. Also, the maximum stresses are 73.08 MPa and 78.52 MPa, which are less than the fatigue strength with a safety factor of 2. It is found that the stress values in the bottom of NURBS-shaped slots are considerably lower than the simple slots, making it possible to design the horns with a higher gain ratio without fatigue failure. Finally, the performance of the present design is verified by doing some experiments on the fabricated horn, which confirms that the proposed design can be successfully utilized as a new method to design wide blade horns.

Design and experimental investigation of stepped horn with a hollow part to allow individual design of amplitude amplification factors for longitudinal-torsional vibration source

In the ultrasonic vibration-assisted manufacturing method using complex vibration, the amplitude amplification factor of horn for each vibration is important. In this paper, we focus on longitudinal-torsional vibration as a complex vibration and propose a stepped horn with a hollow part as a horn that can design the amplification factors of these vibrations individually. The proposed equation for the amplification factor of the horn with a hollow part was derived from the equation of the conventional step horn without a hollow part, and the validity of the proposed equation was verified by the finite element method and experimental measurements. As a result, the validity of the equation was confirmed, and it was clarified that the proposed stepped horn with a hollow part can be individually designed for the amplitude amplification factors of longitudinal vibration and torsional vibration.

Analysis and design of 2-dimensional acoustic particle velocity horns

A two-dimensional acoustic horn packaged with a 2-D acoustic particle velocity sensor (APVS) is presented. The particle velocity amplification factor of the 2-D acoustic horn is analyzed theoretically and experimentally. The experimental results show a good agreement with the theoretical expectations. Compared with the previous horn model, this model considers the gain attenuation at low frequency and the influence of chip assembly deviation. As the particle velocity distribution changes greatly in the boundary layer, the assembly deviation of the chip has a great influence on the package gain. Furthermore, a microphone and the 2-D particle velocity sensor was packaged in the acoustic horn to detect the acoustic pressure and 2-D particle velocity at one point. The acoustic horn has an omnidirectional response for acoustic pressure. By using the mode domain beamforming, the direction of the incident wave was estimated with this two-dimensional sound intensity probe.

Design of Longitudinal-Bending Coupled Horn of a Giant Magnetostriction Transducer

This article presents a design method of Longitudinal-Bending Coupled Horn (L-BCH) of a giant magnetostrictive transducer utilized in spinning ultrasonic machining. The structural parameters are initially determined by the design theory of the horn and thick disc. Then, the effect of the structural parameters of the rotating wheel on the vibration characteristics of the L-BCH are explored by the model and harmonic response analysis through the finite element method. Through continuous modification of the geometrical parameters of the rotary wheel, the L-BCH meeting the requirements of a giant magnetostrictive transducer is designed. Finally, the frequency and amplitude measurements are performed on the prototype by the impedance analyzer and the laser vibrometer. The finite element analysis and experimental results show that: the large diameter, small diameter, thickness, and fillet radius of the rotating wheel have different impacts on the dynamic characteristics of the L-BCH. Among them, the thickness of the rotary wheel has the most significant influence on the natural frequency and amplitude. In addition, the rotating wheel has a pitch circle when the longitudinal-bending coupled vibration occurs, and the structure itself also has the characteristic of amplifying amplitude.