Jun-Yeob Song

Ubiquitous-Based Mobile Control and Monitoring of CNC Machines for Development of u-Machine

This study was an attempt to control and monitor Computerized Numerical Controller (CNC) machines anywhere and anytime for the development of a ubiquitous machine (u-machine). With a Personal Digital Assistant (PDA) phone, the machine status and machining data of CNC machines can be monitored in wired and wireless environments, including the environments of IMT2000 and Wireless LAN. Moreover, CNC machines can be controlled anywhere and anytime. The concept of the anywhere-anytime controlling and monitoring of a manufacturing system was implemented in this study for the purpose of u-manufacturing and u-machines. In this concept, the communication between the CNC controller and the PDA phone was successfully performed anywhere and anytime for the real-time monitoring and control of CNC machines. In addition, the interface between the CNC controller and the developed application module was implemented by Object linking and embedding for Process Control (OPC) and shared CNC memory. For communication, the design of a server contents module within the target CNC was based on a TCP/IP. Furthermore, the client contents module within the PDA phone was designed with the aid of embedded c++ programming for mobile communication. For the interface, the monitoring data, such as the machine status, the machine running state, the name of the Numerical Control (NC) program, the alarm and the position of the stage axes, were acquired in real time from real machines with the aid of the OPC method and by sharing the CNC memory. The control data, such as the start, hold, emergency stop, reserved start and reserved stop, were also applied to the CNC domain of the real machine. CNC machines can therefore be controlled and monitored in real time, anywhere and anytime. Moreover, prompt notification from CNC machines to mobile phones, including cellular phones and PDA phones, can be automatically realized in emergencies.

Knowledge-evolutionary intelligent machine-tools -Part 1 : Design of dialogue agent based on standard platform

In FMS (Flexible Manufacturing System) and CIM (Computer Integrated Manufacturing), machine-tools have been the target of integration in the last three decades. The conventional concept of integration is being changed into the autonomous manufacturing device based on the knowledge evolution by applying advanced information technology in which an open architecture controller, high-speed network and internet technology are included. In the advanced environment, the machine-tools is not the target of integration anymore, but has been the key subject of cooperation. In the near future, machine-tools will be more improved in the form of a knowledge-evolutionary intelligent device. The final goal of this study is to develop an intelligent machine having knowledge-evolution capability and a management system based on internet operability. The knowledge-evolutionary intelligent machine-tools is expected to gather knowledge autonomically, by producing knowledge, understanding knowledge, reasoning knowledge, making a new decision, dialoguing with other machines, etc. The concept of the knowledge-evolutionary intelligent machine is originated from the machine control being operated by human experts’ sense, dialogue and decision. The structure of knowledge evolution in M2M (Machine to Machine) and the scheme for a dialogue agent among agent-based modules such as a sensory agent, a dialogue agent and an expert system (decision support agent) are presented in this paper, with intent to develop the knowledge-evolutionary machine-tools. The dialogue agent functions as an interface for inter-machine cooperation. To design the dialogue agent module in an M2M environment, FIPA (Foundation of Intelligent Physical Agent) standard platform and the ping agent based on FIPA are analyzed in this study. In addition, the dialogue agent is designed and applied to recommend cutting conditions and thermal error compensation in a tapping machine. The knowledge-evolutionary machine-tools are expected easily implemented on the basis of this study and shows a good assistance to sensory and decision support agents.

Design of highly uniform spool and bar horns for ultrasonic bonding

Although the groove and slot have been widely utilized for horn design to achieve high uniformity, their effects on uniformity have not been analyzed thoroughly. In this work, spool and bar horns for ultrasonic bonding are designed in a systematic way using the design of experiments (DOE) to achieve high amplitude uniformity of the horn. Three-dimensional modal analysis is conducted to predict the natural frequency, amplitude, and stress of the horns, and the DOE is employed to analyze the effects of the groove and slot on the amplitude uniformity. The design equations are formulated to determine the optimum dimensions of the groove and slot, and the uniformity is found to be influenced most significantly by the groove depth and slot width. Displacements of the spool and bar horns were measured using a laser Doppler vibrometer (LDV), and the predicted results are in good agreement with the experimental data.

Introduction of case study for M2M intelligent machine tools

In the near future, machine tools will be more improved in the form of a knowledge-evolution based intelligent device. The final goal of this study is to develop an intelligent machine tools having knowledge-evolution capability in Machine to Machine (M2M) wired & wireless environment. The knowledge-evolution based intelligent machine tools is expected to gather knowledge autonomously by producing knowledge, understanding knowledge, reasoning knowledge, making a new decision, dialoguing with other machines, etc. The concept of the knowledge-evolution intelligent machine is originated from the machine control being operated by sense, dialogue and decision of human-expert. With intent to develop the knowledge-evolution based machine tools, the structure of knowledge-evolution in M2M and the scheme for a dialogue agent among agent-based modules such as a sensory agent, a dialogue agent and an expert system (decision support agent) are presented in this paper. And work-offset compensation from thermal change and recommendation of cutting condition are on-line performed for knowledge-evolution verification.

Pre-bonding method using self-alignment effect for multichip packaging

An efficient C2C/C2W oxide bonding technique using self-alignment effect of a pair of hydrophilic chip surfaces, which are activated by plasma, is applied to 3D stacking of multichip packaging in this work. Self-alignment and pre-bonding technique can provide high-speed bonding process and high-precision chip alignment accuracy simultaneously without high-precision chip manipulator. Through experiments, we could acquire high hydrophilic silicon surfaces using plasma surface activation and measured position errors and rotational error of aligned chips is smaller than 5µm and 0.04 degrees respectively because of self-alignment effect between hydrophilic surfaces of chips. In addition, temporary bonding is formed successfully by secondary bonding between silanol groups (Si-OH) on the hydrophilic silicon chip surfaces when the DI water is evaporated by heating, which prevents contamination of bonding surface and helps of manipulation of multi-stacked chips easily.

A study on wafer level TSV build-up integration method

TSV (Through-Silicon Via) 3D packaging technology has been and continues to be investigated by many of the semiconductor manufacturer and research institute as a practical way to achieve higher performance and smaller form factors. Compared with conventional 2D packaging, this can increase packing density and reduce power consumption dramatically because of shorter interconnection by vertical directional stacking. So far 3D stacking technology based on W2W bonding has developed widely such as 3D Image sensor and 3D stacking memory because it has the advantage of easier alignment and higher throughput compared with chip-to-chip bonding. However, the wafer level 3D stacking method can be only applicable to products with high production yield because overall yield of 3D stacking chips depends on the yield of multiple stacked layers. In this paper, we suggested wafer level build-up stacking process using oxide bonding and molten metal filling newly, which temporary bonding process is unnecessary and demonstrated it through experiments. Thermal stress analysis was carried out to compare the structural reliability between conventional TSV and the proposed TSV model. The simulation results indicate that the proposed TSV model is more reliable than the conventional model with respect to stress in the stack chip.

Curing Behaviors of UV-Curable Temporary Adhesives for a 3D Multichip Package Process

Temporary bonding adhesives for a three-dimensional (3D) multichip package process have been synthesized. To enhance the thermal stability, the adhesives used a fluorinated silicon urethane acrylic binder and ultraviolet (UV) curing for crosslinked network structures. Focusing on different photoinitiator contents and UV doses, the UV-curing behaviors and thermal stability were studied using Fourier-transform infrared spectroscopy attenuated total reflectance, gel fraction, swelling ratio, shrinkage, and thermogravimetric analyses.

Bonding head design for thin wafer

In this paper, porous vacuum picker and bonding head to impose uniform pressure on all the surface of wafer in the bonding process are proposed newly. Porous vacuum picker could reduce deformation and warpage problem during handling thin wafer because it has many number of small vacuum hole which induce small vacuum pressure at those holes region. Also, to impose uniform pressure on the wafer under bonding process, bonding head is designed using air piston type with metal ball joint, which automatically compensate for coplanarity problem of bonding pad. FEM analysis and experiments are conducted to evaluate the performance of porous vacuum picker and bonding head of air piston type.

Study on a robust insert-bump (ISB) bonding technique for a 3D package

The Cu pillar bump to Cu pillar bump bonding process, commonly used in bonding technology for the 3D stacking of TSV (through silicon via) formed chips, requires an additional process for the generation of bumps on the face and back-side of the chip, and it has a drawback in that it is structurally vulnerable to mechanical stresses, such as thermal stress. This study proposes an ISB (insert-bump) bonding process to overcome such drawbacks. Compared to the conventional Cu pillar bump to Cu pillar bump bonding process, the ISB bonding process has advantages in that it is simple and has high mechanical reliability of the package due to the mechanical interlocking. The stress distributions at the joints of the packages produced from Cu pillar bump to Cu pillar bump bonding and ISB processes were compared and analyzed through FEM analyses, and characteristics analyses of the fracture mode and joint characteristics; process variable optimization with respect to the bonding parameters was also conducted through experiments. The results of the analyses and experiments verified that the ISB bonding process yields a bonding strength of 917.6 mgf/bump, which is approximately twice as much as that of the conventional Cu pillar bump to Cu pillar bump bonding, and which yields a highly reliable mechanical structure.

Autonomous Compensation of Thermal Deformation during Long-Time Machining Process

The biggest factors, which lower the machining accuracy of machine, are thermal deformation and chatter vibration. In this article, we introduce the development case of a device and technology that can automatically compensate thermal deformation errors of machine during long-time processing on the machine tool’s CNC (Computerized Numerical Controller) in real time. In machine processing, the data acquisition of temperature signal in real time and autocompensation of the machine origin of machine tools depending on thermal deformation have significant influence on improving the machining accuracy and the rate of operation. Thus, we attempts to introduce the related contents of the development we have made in this article : The development of a device that embedded the acquisition part of temperature data, linear regression to get compensation value, compensation model of neural network and a system that compensates the machine origin of machine tool automatically during manufacturing process on the CNC.