Effect of Tool Wear on Force and Quality in Dam-Bar Cutting of Integrated Circuit Packages

2000 ◽  
Vol 123 (1) ◽  
pp. 34-41 ◽  
Author(s):  
C. F. Cheung ◽  
W. B. Lee ◽  
W. M. Chiu

Dam-bar cutting is an essential trimming process in which the dam-bars in between the leads of Integrated Circuit (IC) packages are removed after encapsulation and deflashing. There are stringent requirements imposed on the quality of the sheared dam-bar edges so as to avoid the post-process failure of the package during assembly on to printed circuit boards. In this paper, a detailed analysis of the wear characteristics of the dam-bar cutting tools and their effects on the force and quality of dam-bar cutting process is reported. The correlation between the peak dam-bar cutting force and the tool wear was also studied under various combinations of wear states of the punch and die. Based on the experimental findings, relationships have been built to correlate the states of wear of the punch and die to the protrusion and burr height of the dam-bar sheared edge. Hence, revised tool life criteria were proposed for the quality control of dam-bar cutting process. The results of the analysis provide an important means for the on-line monitoring of tool wear and edge quality of dam-bar cutting process in the IC packaging industry.

2006 ◽  
Vol 532-533 ◽  
pp. 644-647
Author(s):  
Yi Ping Zhang ◽  
Jiu Hua Xu ◽  
Guo Sheng Geng

Ti-6.5Al-2Zr-1Mo-1V is a near alpha titanium alloy strengthened by solid solution with Al and other components. In this study, a series of experiments on tool wear and surface integrity in high speed milling (HSM) of this alloy were carried out. The tool lives under different cutting speeds were studied and the corresponding empirical equation of tool life was derived. Additionally, the wear mechanism of cutting tools was also discussed. Finally, surface integrity, including surface roughness, metallograph, work hardening and residual stresses, were examined and analysed. The result shows that good surface quality of workpiece could be obtained in HSM of the alloy.


2016 ◽  
Vol 1815 ◽  
Author(s):  
John Henry Navarro Devia ◽  
Willian Aperador Chaparro ◽  
Jairo Cortes Lizarazo

ABSTRACTThe main purpose of coatings is to increase the lifetime of cutting tools, to perform continuous and economical material removal process, reducing the frequency of sharpening or replacement of the tool, which contributes to increase quality of product. Therefore, hafnium nitride (HfN) single layer coatings were deposited on High-speed steel by Magnetron Sputtering physical vapour deposition (PVD). The machining on AISI 1020 steel samples were carried out in a computer numerical control (CNC) machine, using coated and uncoated tools, the temperature of the different components were measured (steel bar and tool), due to continuous temperature measurement help to predict tool wear and the quality of finished piece [1] . In order to evaluate wear resistance and performance, not only temperature data were compared, the tool wear morphological analysis for flank wear was carried using Scanning Electron Microscopy (SEM), and work pieces roughness were checked through their surfaces in an Atomic Force Microscopy (AFM). In most of the parameters evaluated differences between the tools were identified, and results reveals that on HfN coating, occurs less wear, due the proportionality between the energy transfer and the tool deterioration, also the coating improves surface finish of the machined part; all of them are reflected in changes on process temperatures. The use of single layer HfN coating on cutting tools could increase their lifetime, improve the quality of the work piece, and even reduce process time and cost.


Author(s):  
Pierre-Jean Méausoone ◽  
Alfredo Aguilera

Woodworking is based on a trinomial machine/piece/tool. For maximum quality of the manufactured piece, it is important not to separate this trinomial, but the limited life of tools prevents that permanent contact. This phenomenon is due to the wear of the cutting parts of the tools. The prevention of wear is based on two methods. The first is to anticipate the end point of tool wear, changing these after a fixed period, no matter what. The other school is to recognize the tool wear at the event: the tools are changed once they are really worn out, finding faults on manufactured parts. A worn tool generates pieces with non-compliant quality or even unusable. A deeper understanding of wear and its consequences would change the tool at the right time. The tool wear for wood is due to several phenomena interacting with each other. The first dominating phenomenon is a corrosive attack that decreases the mechanical strength of the surface. The second is an abrasive attack whose work is facilitated by the reduced resistance of the surface. Repeated shocks can be in the degradation of the cutting edge, temperature acting as amplifier to wear. Understanding of the wear patterns can characterize the life of tools by wear measurement to find ways to extend this period with development of tool coatings, while maintaining optimal conditions for woodworking to get the best finish.


Micromachines ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 932 ◽  
Author(s):  
Valeria Marrocco ◽  
Francesco Modica ◽  
Vincenzo Bellantone ◽  
Valentina Medri ◽  
Irene Fassi

In this paper, the effect of the micro-electro discharge machining (EDM) milling machinability of Si3N4–TiN workpieces was investigated. The material removal rate (MRR) and tool wear rate (TWR) were analyzed in relation to discharge pulse types in order to evaluate how the different pulse shapes impact on such micro-EDM performance indicators. Voltage and current pulse waveforms were acquired during micro-EDM trials, scheduled according to a Design of Experiment (DOE); then, a pulse discrimination algorithm was used to post-process the data off-line and discriminate the pulse types as short, arc, delayed, or normal. The analysis showed that, for the considered process parameter combinations, MRR was sensitive only to normal pulses, while the other pulse types had no remarkable effect on it. On the contrary, TWR was affected by normal pulses, but the occurrence of arcs and delayed pulses induced unexpected improvements in tool wear. Those results suggest that micro-EDM manufacturing of Si3N4–TiN workpiece is relevantly different from the micro-EDM process performed on metal workpieces such as steel. Additionally, the inspection of the Si3N4–TiN micro-EDM surface, performed by SEM and EDS analyses, showed the presence of re-solidified droplets and micro-cracks, which modified the chemical composition and the consequent surface quality of the machined micro-features.


2022 ◽  
Author(s):  
S.G. Novikov

Abstract. Vibration during turning is a consequence of premature tool wear and an increase in the roughness of parts. The designs of tool bits that increase their durability, reduce vibrations arising during the cutting process, and improve the quality of processing are of practical and scientific interest. Existing developments of vibration-damping bits with elastic damping inserts of constant rigidity, in which a holder or mandrel with a cut-off insert is installed, do not meet the requirements for the efficiency of vibration reduction due to the impossibility of the necessary vibration damping; the consumption of insert materials is high. Innovative designs of tool bits with inserts formed by semi-inserts with different rigidity are proposed, which allows improving the quality of processing by increasing the efficiency of vibration damping, reducing material consumption, because the length of the semi-inserts is less than half the length of the full insert. The tool bits can be used in the area of cutting materials, mechanical engineering and tool manufacturing.


Author(s):  
S. Khadpe ◽  
R. Faryniak

The Scanning Electron Microscope (SEM) is an important tool in Thick Film Hybrid Microcircuits Manufacturing because of its large depth of focus and three dimensional capability. This paper discusses some of the important areas in which the SEM is used to monitor process control and component failure modes during the various stages of manufacture of a typical hybrid microcircuit.Figure 1 shows a thick film hybrid microcircuit used in a Motorola Paging Receiver. The circuit consists of thick film resistors and conductors screened and fired on a ceramic (aluminum oxide) substrate. Two integrated circuit dice are bonded to the conductors by means of conductive epoxy and electrical connections from each integrated circuit to the substrate are made by ultrasonically bonding 1 mil aluminum wires from the die pads to appropriate conductor pads on the substrate. In addition to the integrated circuits and the resistors, the circuit includes seven chip capacitors soldered onto the substrate. Some of the important considerations involved in the selection and reliability aspects of the hybrid circuit components are: (a) the quality of the substrate; (b) the surface structure of the thick film conductors; (c) the metallization characteristics of the integrated circuit; and (d) the quality of the wire bond interconnections.


Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 353
Author(s):  
Kun-Cheng Ke ◽  
Ming-Shyan Huang

Conventional methods for assessing the quality of components mass produced using injection molding are expensive and time-consuming or involve imprecise statistical process control parameters. A suitable alternative would be to employ machine learning to classify the quality of parts by using quality indices and quality grading. In this study, we used a multilayer perceptron (MLP) neural network along with a few quality indices to accurately predict the quality of “qualified” and “unqualified” geometric shapes of a finished product. These quality indices, which exhibited a strong correlation with part quality, were extracted from pressure curves and input into the MLP model for learning and prediction. By filtering outliers from the input data and converting the measured quality into quality grades used as output data, we increased the prediction accuracy of the MLP model and classified the quality of finished parts into various quality levels. The MLP model may misjudge datapoints in the “to-be-confirmed” area, which is located between the “qualified” and “unqualified” areas. We classified the “to-be-confirmed” area, and only the quality of products in this area were evaluated further, which reduced the cost of quality control considerably. An integrated circuit tray was manufactured to experimentally demonstrate the feasibility of the proposed method.


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