Purpose - The purpose of this paper is to present a method for evaluating the structural dynamic characteristics of a flying probe tester.Design/methodology/approach - The dynamic characteristics of a flying probe tester framework were analyzed based on a finite element analysis method. First, modal analysis was carried out to characterize the modal parameters of the structure. Second, the harmonic response was analyzed according to the modal analysis and the response curve of the structural system was studied. Finally, transient analysis was conducted to obtain the transient response of the structures at the beginning of the vibration.Findings - The natural frequency and the response frequency of a natural granite structure was the highest and the transient vibration displacement amplitude was the smallest compared with cast iron and artificial stone structures.Originality/value - A comprehensive understanding of the dynamic characteristics of the framework of a flying probe tester with three different materials has been achieved. The results of the analyses provide a reference for the framework design of a flying probe tester.

D rilling is a key process in the production of printed circuit board (PC B ). Pressure foot plays an im portant role in the drilling process,and the w orkpiece m achining quality is close related w ith the com bining form of pressure foot and sucking dust cover. T he m ainstream com binatorial structures in the m arket are analysed w ith the help of test com bined w ith num erical sim ulation m ethod. T he paper presents a system atic solution of pressure foot design in engineering,appropriate param eter is obtained on the basis of a series of tests to achieve high perform ance of dust collection and high quality drilling.

T he different bodies of PC B N C m ulti-axis connecting drilling m achine w ith different structure and different m aterials usually adopt different structural support, this paper aim s at tw o kinds of external support structure tested chatter, find a large difference of PC B N C drilling m achine dynam ic perform ance. T hrough sim ulation and test and B y m aking use of the experim ent m eans to reveal the deform ation of supporting structure and the supporting structure leads to the reasons of the differences of PC B N C drilling m achine dynam ic perform ance, provide availability data basis for im proving the dynam ic perform ance of PC B N C drilling m achine.

Purpose – The purpose of this paper is to verify the feasibility and reliability of mineral casting applied in high-precision printed circuit board (PCB) drilling machine. The mechanical properties of machine frame are quantified to provide a solution for machine tool industry to seek a perfect substance competing with classic materials such as cast iron and granite. Design/methodology/approach – The optimal design of machine frame is performed via the CAD system combined with finite element analysis (FEA). The mechanical properties of the frame elements are evaluated by a series of mechanical experiments: static performance is quantified by flatness tests, dynamic behavior is estimated by experimental and numerical models, respectively. Meanwhile, the performance of the frame element with traditional materials is examined experimentally. Findings – Mineral casting parts can be successfully applied to PCB drilling machine to meet high accuracy requirements. The characteristic of mineral casing gives the most possibilities in structural design. The frame parts show good static/dynamic behaviors by structural optimization processes. Especially, the machine frame with mineral casting gains a great weight reduction compared with traditional materials. Originality/value – The application of mineral casting in PCB drilling machine offers greater design flexibility and innovative system solutions. The combination of FEA is convincing to achieve optimal structure and ideal weight to maximize the economic and technical benefits. Moreover, lightweight design of machine structural components achieves not only higher kinematic/dynamic precision but also considerable cost reduction.

基于Adams多体动力学分析软件对飞针测试机同步带传动系统进行仿真计算,研究同步带的运动特性.通过仿真获得测试头的加速度、速度及位移和同步带的受力等曲线,为飞针测试机同步带传动系统的设计和改进提供参考.

The invention provides a dynamic error measuring system of a high-speed machine tool. The dynamic error measuring system of the high-speed machine tool comprises a reference substance, a scale device and a high-speed image recording device. The scale device is fixed to a machine tool large component moving at high speed and moves at high speed along with the machine tool large component. The high-speed image recording device is used for recording the scale, located on the scale device, of the reference substance so that the deviation between moving trails of the large component of the machine tool can be obtained in the operating process. The dynamic error measuring system of the high-speed machine tool comprises a machine tool small component, a scale device and a high-speed image recording device, wherein the scale device is fixed to one side of the machine tool small component moving at high speed, and the high-speed image recording device is arranged on the other side of the machine tool small component moving at high speed and used for recording the scale, on the scale device, of the machine tool small component moving at high speed. The high-speed image recording devices can directly read the scales, on the scale devices, of the machine tool large component or the machine tool small component moving at high speed, so that the dynamic error of the machine tool large component or the machine tool small component moving at high speed is directly, effectively and conveniently measured.

Purpose - The purpose of this paper is to present and describe a solution of aluminum substrate drilling.Design/methodology/approach - The development of LED and printed circuit board with metal substrate are reviewed first. Then the challenges of drilling metal substrate, particularly the aluminum substrate, are described. To find the solution, coated micro drill bit with optimized helix angle is developed. The performance of developed micro drill bit is examined via drilling force investigation. Finally, the drilling tests are conducted to verify the solution of aluminum substrate drilling.Findings - Coated drill bit is a very good choice to solve the problems of drilling burr and chip clogging in aluminum substrate drilling. The reason is that the drilling force can be obviously reduced by using a coated drill bit. The drill bit with medium helix angle is beneficial to prevent chip clogging. A satisfactory solution of aluminum substrate drilling can be achieved by applying coated drill bit with medium helix angle together with appropriate entry board.Originality/value - The paper presents a satisfactory solution of aluminum substrate drilling. By employing the presented solution, the problems of drilling burr and chip clogging can be avoided in aluminum substrate drilling.

In order to improve processing quality of high-speed and high-precision equipment,CMAC is combined with PID to become the control strategy including PID and CMAC based on its characteristics of no accurate mathematical model of controlled object,strong nonlinear fitting ability and highly adaptability in operating conditions;based on the Open Servo function of Turbo PMAC,the control strategy including PID and CMAC has been realized on Turbo PMAC motion controller.The test results show that the control strategy including PID and CMAC can better improve the system positioning performance and following performance.

The placement machine was simulated by multidisciplinary co-simulation method in various working conditions, and its dynamic accuracy was studied by simulation. According to the structure form of the placement machine, the virtual prototype for co-simulation was built. The impact of all sorts of parameters on the system dynamic accuracy was simulated including the stiffness and damping of the slider and the shaft coupling, the friction coefficient and the mass distribution etc. The result shows this method is able to predict the dynamic performance and the control margin of the whole machine, instruct the design optimization and the selection, and provide the good design thought and direction for the matching design of the machinery and controlling system.

PurposeThe purpose of this paper is to present a system for accurately measuring drilling force in the printed circuit board micro drilling process and to characterize the drilling force to provide a better understanding of the micro drilling process.Design/methodology/approachThe drilling force measurement system was established first. Then the drilling force in printed circuit board micro drilling process was characterized experimentally. In particular, the drilling forces in drilling halogen‐free and lead‐free assembly compatible printed circuit boards and the drilling force characteristics in ultra small hole drilling were investigated.FindingsA drilling force measurement system, with the key component of a KISTLER 9256C2 dynamometer, can accurately measure the drilling forces in the printed circuit board micro drilling process. The micro drilling process can be characterized by drilling force. Meanwhile, drilling force is very sensitive to drill breakage and drilling force can be utilized to detect drill breakage in the micro drilling process.Originality/valueThe paper presents a system for accurately measuring the drilling force. Drilling force provides fundamental information for the optimal design of micro drill bits. Drilling force can also characterize the micro drilling process, especially the ultra small hole micro drilling process.

The tracking performance of the traditional Servo Moving System is Likely to be affected by the outside interference,speed changes,non-linear and other factors.The on-line adjustment algorithm is proposed to switch real-time control parameters based on speed changes,and the algorithm is realized on PMAC controller.Experiments show that this algorithm is effective to improve the tracking performance of Servo Moving System.

The development of PCB CNC drilling machine is toward high-precision and high-speed, and the impact of the join cannot be ignored. Based on the finite element software, the finite element model of the drilling shaft system including the joins is established; the modal analysis and the frequency response analysis are performed on the drilling shaft system, the natural frequencies and mode shapes are obtained; the effect of the different parameters on the natural frequencies is analyzed, and the basic data can be obtained from the analysis.

Based on multi-body dynamics, the virtual prototype model of the tape feeder is set up, and the impact of the external torque and the friction coefficient on the whole system is analyzed. Simulation results show that the external torque has great influence on the required motor torque: when the external torque increases from 50N.mm to 200N.mm, the required motor torque increases from 75.217N.mm to 223.98N.mm. The friction damping also has great influence on the motor torque: when the dynamic friction coefficient increases from 0.001 to 0.009 and the static friction coefficient increases from 0.003 to 0.011, the required motor torque increases from 106.92N.mm to 158.81 N.mm.

The rotary mounting head is one kind of the multi-axis mounting head, and it is mainly applicable to the placement of the relatively small SMC/SMD. The image of the 12-axis is processed together synchronously in order to save the processing time of shooting and computing. Continuous grasping and placing in a working cycle decrease the movement time so that the efficiency of the placement can greatly be improved. The built-in vision system of the placement machine is used to perform the online accuracy test and compensation, resulting in great improvement of placement accuracy.

Mounting head is the key component of the placement machine to achieve mounting function, and it is a typical θ-Z mechanism where the mounting axis realizes the rotary movement and the axial line movement. Smaller size, less weight, higher speed and higher precision of θ-Z movement are the main objectives in the design of the mounting head. The bearing groups and the overall frame structure can guarantee the good characteristics of response and the high stiffness in the mounting structure.

According to the multidisciplinary characteristics of placement machine, a development sys- tem of the digital prototype on the placement machine is built. In the design phase, the multidisci- plinary design and simulation are performed to check and test the product functionality and perfor- mance. The various system parameters are coordinated to make our products meet the design indica- tors, and the conflict and interference between the various disciplines are solved and the best coupling is achieved. This will significantly shorten the product development cycle, reduce the product develop- ment costs, and improve the product quality and the system performance.

In response to the problem that the dynamic model for placement machine is unknown and cannot be measured directly in frequency domain,a servo identification system is built based on the placement machine,including generation and loading of excitation signals,data acquisition,plant identification and analysis of the general control performance.The use of servo identification system can estimate the dynamic model and analyze the control performance of the servo system quantitatively.The servo identification system provides condition for intuitively tuning the control parameters and applying advanced servo control strategy,it also provides an effective means of improving the placement efficiency and precision.

PCB ( Printed Circuit Board) is a kind of carrier of electronic products which has a distinc-tive feature involving light-size, light-weight, compressed-density, high-reliability and low-cost. PCB drilling machine tool as the key equipment used in PCB processing field is in procession of characteris-tics of high-speed, high-precision, high-stability and low-budget. Those requirements of high-perfor-mance drilling machine make it hard of product research and development. It is difficult to meet the re-quirement of design by tradition method. This paper is to provide up-to-data of market application and a new idea for product development for national and international fellow traders through studies into function design of PCB drilling equip-ments, market-application statistics,and comparisons among well-known products.

The package types and packaging forms of SMC/SMD are very many, and new forms con- tinue to emerge. In order to upgrade the mounting accuracy and speed of the placement machine, the existing vision algorithm must be continuously optimized and the new algorithm must be produced so that the positioning and centering functions of the visual system can be improved. The image analysis test platform including the hardware and software is established in order to finish the image test and analyses of all the components. Therefore, the computing speed and accuracy of the vision system can be improved and the algorithm can be well shared and reused in the product development, and it can shorten the development cycle and improve product quality.

Based on the software ADAMS(Automatic Dynamic Analysis of Mechanical System),vibration optimization is performed for a placement machine.The structure of the placement machine is analyzed,and multi-body vibration models are established based on the principles of multi-body system.The influence of its rigidity and damping on vibration is determined in the analysis.Vibration optimization of the placement machine is carried out for the parameters that have the greatest influences on the system.Analysis results show that the conjunction parameters of the down-rack and the ground have less influence on the vibrant performance of the placement head than the conjunction parameters of the Y-carriage and the connecting plate of the gantry.The oscillation amplitude in the vertical direction is controlled within 10 micrometers,and the vibration performance of the system is improved.