Papers by Keyword: Strip

Abstract: Sulfuric Peroxide Mixture (SPM, H₂SO₄ + H₂O₂) has been widely used in semiconductor manufacturing processes due to its high reactivity and attractive price. However, SPM releases SO₄^2- ions that can be high impact on the environmental contaminations. Therefore, the SPM process requires a high cost wastewater treatment. So, the development of alternative chemicals has been becoming an important task in the semiconductor manufacturing process. In this paper, we evaluated the feasibility of replacing SPM with dissolved ozone water (DIO₃) in the wafer cleaning process, and confirmed that the Particle removal efficiency (PRE) was improved around 68% by mixing with diluted hydrofluoric acid (DHF). And, the PRE was also increased when the concentration of ozone in dissolved ozone water increased. Additionally the PRE was improved up to 98% by combining physical cleaning after O₃ process.

Abstract: Manufacturing of bimetallic brass-aluminum-brass strips is connected with a number of technological features. The features under consideration are cladding (welding) of the primary components, annealing of metal compositions and strain modes assignment. The purpose of the studies upon the development of bimetallic brass-aluminum-brass strips production technologies in SUSU is to analyze the modes, as well as to elaborate recommendations for the primary components thickness selection, strain modes assignment and annealing using bell-type furnace and strand-type furnace. The performed studies resulted in recommendations dealing with annealing cycles. The studies have also delivered the regression ratio between the thickness selection of primary components during the cladding operation, and the supreme total strain. A correct ratio prevents from the surface ruptures on the bimetallic brass-aluminum-brass strips surface while rolling.

Abstract: The application of the SOH Mask created a new defect. Defect image is similar to ESD defect, which occurred on POLY and METAL film. Stringent experiments were conducted in order to prove the correspondence principle of the defect of SOH and the mechanism of the ESD defect. Finally, it’s concluded the defect of SOH is equal to the ESD defect. ESD defect occurred also on SOH film, like POLY or METAL film.

Abstract: In this study, the possibility of producing of flat aluminum strips with tailored mechanical properties across their width by means of rolling was examined. The aim of the work was an experimental analysis of the effect of cold rolling of the strips with a pre-profiled cross-section in flat rolls. Because of different work hardening of the various elements of the pre-profiled strips a characteristic profile of mechanical properties over the strips cross-section was created. The performed tensile tests and hardness measurements proved the possibility of setting of tailored properties in flat strips by means of rolling. The difference between the mechanical characteristics of various strip’s elements for the selected aluminum alloy can reach 40%.

Abstract: Setup calculation function of the process control system for tandem cold rolling mills not only determinates the dimension accuracy of finished strip materials directly, but also affects the control of surface quality of strip materials. In the present work, an attempt was made to develop a new setup calculation method for tandem cold rolling mills to maximize the throughput and improve the surface quality of strips. Based on the application platform for level-2 process control system, the modular design method was adopted, and then the setup calculation function was developed. And four functional modules consisting of preset preparation module (PPM), basic setup calculation module (BSCM), dynamic setup calculation module (DSCM), and adaptive calculation module (ACM) were developed. The preset data from PPM were used in equipment of level-1 process control system, and the purposes of BSCM was to achieve high quality of products, reduce off thickness deviation and achieve stable rolling at maximum possible rolling speed for raising productivity. In order to minimize off error of preset and actual data, DSCM was provided. Thanks to the design of ACM, accuracy of mathematical model can be effectively improved on line. Ultimately, the precise model on setup calculation method for cold tandem rolling of strip steels was established, and then it was put into practical production. Statistics analysis showed that the measured data was in excellent agreement with the model, and exactly, the relative deviations on rolling force and delivery thickness of strips were less than 3.67% and 0.42%, respectively. The new setup calculation method has high precision and good generalization capability.

Abstract: The rolling force calculation procedure of strip cold rolling is developed based on influence function method, with consideration of the couple of roll flattening model and rolling force model. With the procedure total rolling force and the distribution of rolling force per width of each pass for HC mill are calculated using sampling data obtained from actual strip rolling. Comparing the calculation results with actual measured value, it is shown that the calculated total rolling forces are similar to actual data, and the distribution of rolling force per width is consistent with the actual status. It proved that the calculation method introduced in this paper is an effective method to calculate rolling force, and it can be used in the process control of strip cold rolling mill.

Abstract: The inspection of sheet strips post high-speed punching mainly relies on the manual off-line inspection with basic inspection equipment or CCD equipment. Such inspections cannot reflect the real-time conformity of strip machining, and in severe cases, lead to rejects in batches, causing a tremendous waste in production. Now that the application of charge-coupled device (CCD) technology in product inspection is relatively mature, it would be a very good thought to adopt the CCD technology to realize real-time online inspection of conformity of the high-speed punched strips. KeyWords: CCD technology; strip; online automatic inspection; progressive die

Abstract: Thickness model adaption plays a important role in obtaining strip with high thickness precision. In order to improve the thickness precision, a complete thickness model adaption system has been designed for every specific model used in the setup system including gap position model, temperature model, rolling force model. Snapshot data and stretch equation are used to adapt gap position. Forced convection coefficient is selected as adaption parameter. A deformation resistance-based fitting quadratic curve is proposed in rolling force adaption, it can be inherited to any other thick range class and a quick thickness adaption method is introduced. Application results show that this adaptive system is with high accuracy, quick adaption and high stability.

Abstract: Aim to produce metal strips in millimeter scale, the Top Side-pouring Single Roll Casting process and the Top Side-pouring Twin Roll Casting process were investigated in this paper, using commercially pure lead and commercial-purity aluminum as the experimental materials. Numerical simulation was conducted before the experiment. The results show that, the Top Side-pouring Single Roll Casting process and the Top Side-pouring Twin Roll Casting process can both realize the uniform flow distribution and rapid solidification, but the surface of the strips cast by the former are irregularity because of free solidification, while that from the latter present a state of rolling. And one can change the gauge of nozzle and the speed of cooling roll, to regulate the thickness of thin strips, and by changing the shape of the nozzle, the thickness distribution can be handled.

Abstract: In order to improve the calculation accuracy of tension distribution, a new method to calculate tension distribution for strip cold rolling is carried out. First, exit unit tension calculation model is developed by using variational calculus method. Then combined with divided element method, tension distribution and rolls deformation model are established, and the corresponding procedure is developed. Further, contact pressure between rolls and tension distribution of a single-stand reversing cold mill are calculated with the procedure. And it is proved that the results of the calculated data agreed well with the measured value. This verifies that the calculation method is reliable.