Papers by Keyword: Jetting Dispenser

Abstract: In this paper, a new jetting dispensing system for underfill process is proposed and experimentally evaluated. The suggested system is actuated by two piezostack actuators positioned in parallel and a lever-hinge mechanism is used for amplifying a displacement of the piezostack actuators. After describing the geometric configuration and working principle of the proposed system, both geometric and material information are explained. In order to evaluate the performance of the proposed system experimentally, an experimental apparatus are manufactured. The needle displacement and jetting weight of single dot are experimentally obtained and displayed.

Abstract: This article presents performance results of a novel jetting dispenser system actuated dual piezostack actuators. The proposed piezo jetting dispenser system consists of a couple of piezostack actuators, lever mechanism, and needle part. The proposed dispenser can provide a very small dispensing dot size of high viscous adhesive, 10,000cp at 100°C, at a high dispensing flow rate in semi-conductor packaging processes. After describing the mechanism and operating principle of the proposed dispenser, a mathematical model of the system is obtained by considering behaviors of the piezostack, the return spring, the dispensing needle, and the adhesive fluid dynamics. For the computer simulation, the specific geometric dimensions of the proposed jetting dispenser are chosen in order to achieve operation requirements: needle motion amplitude: up to 0.15 mm; operating frequency: up to 500 Hz. With the high viscosity conditions, the dispensed amount of the adhesive and the maximum displacement of the piezo and the needle at 500Hz are evaluated in time domain.

Abstract: Ink marking is a key process for die sorting of IC wafer manufacturing. Intensive production of wafer is urging the inkers for more rapid and more stable ink marking performance on surface of defective wafer dies safely. In this paper, a non-contact jetting dispenser is introduced to the wafer die marking. After presenting the mathematical description of dynamic fluid for 2-phase flow, numerical simulations are launched to reveal the characteristics of droplet generation and key factors are discussed. A jetting dispenser is developed and experimental results are analyzed. According to the simulative results and the dotting performance shown in experiments, the non-contact jetting dispenser is capable for wafer die marking in dotting efficiency and stability.

Abstract: This paper presents a new type of jetting dispenser driven by a piezostack. Via a flexible beam mechanism, the amplitude of a needle motion is amplified to such a value that can make a dispensing of medium and high viscosity adhesive. By designing the flexible beam with high resonant frequency, the dispenser can operate at a frequency much higher than that of conventional dispensers. Therefore, it is expected that the dispenser can provide very small dispensing dot size at high dispensing flow rate, which is imperatively required in modern semiconductor packaging processes. Furthermore, the dispensing flow rate and dot size can be effectively controlled by driving voltage applied to the piezostack. After describing the mechanism and operational principle of the dispenser, a mathematical model of the system is derived by considering dynamic behaviors of structural parts such as the piezostack, the flexible beam and the needle structure, and the adhesive fluid dynamics. In the modeling, a lumped parameter method is applied to model the adhesive dynamics and the governing equation of the whole dispenser is then derived by integrating the structural model with the fluid model. Based on the proposed model, the dispenser is designed and manufactured. Subsequently, dispensing performances such as a dot size and dispensing flow rate are experimentally evaluated.