A Study on Wire Sweep in Encapsulation of Semiconductor Chips Using Simulated Experiments

1995 ◽  
Vol 117 (3) ◽  
pp. 178-184 ◽  
Author(s):  
Sejin Han ◽  
K. K. Wang
Keyword(s):  
General Shape ◽  
Homogeneous Fluid ◽  
Dead Weight ◽  
Transfer Molding ◽  
Straight Wire ◽  
Semiconductor Chip ◽  
Series Of Experiments ◽  
The Wire ◽  
Semiconductor Chips ◽  
Made In

An effort has been made in this study to develop a model which can predict wire sweep during semiconductor chip encapsulation with transfer molding. The calculation of wire sweep during encapsulation depends on many factors. In this study, a step-by-step approach has been used considering one factor at a time. As the first step, the wire deformation has been measured and calculated under a known dead-weight loading. The next step has been to measure and calculate the deformation of a single straight wire attached to the mid-plane of a rectangular cavity due to the flow of a clear and homogeneous fluid. Finally, the wire deformation due to the flow has been measured and calculated when a wire of general shape is attached to a leadframe. The effect of bubble on the wire-sweep has been analyzed qualitatively. Through this series of experiments, a first step in the development of model for the prediction of wire sweep during chip encapsulation has been made.

scholarly journals II. On some phenomena exhibited by gun-cotton and gunpowder under special conditions of exposure to heat

1864 ◽  
Vol 13 ◽  
pp. 204-217
Keyword(s):  
Rapid Method ◽  
High Temperatures ◽  
Royal Society ◽  
Sufficient Accuracy ◽  
Hot Wire ◽  
Full Extent ◽  
Mechanical Condition ◽  
Series Of Experiments ◽  
The Wire ◽  
Made In

The experiments upon which I have been engaged for some time past, in connexion with the manufacture and properties of gun-cotton, have brought under my notice some interesting points in the behaviour of both gun. cotton and gunpowder, when exposed to high temperatures, under parti­cular conditions. I believe that these phenomena have not been previously observed, at any rate to their full extent, and I therefore venture to lay before the Royal Society a brief account of them. Being anxious to possess some rapid method of testing the uniformity of products obtained by carrying out General von Lenk’s system of manu­facture of gun-cotton, I instituted experiments for the purpose of ascer­taining whether, by igniting equal weights of gun-cotton of the same com­position, by voltaic agency, within a partially exhausted vessel connected with a barometric tube, I could rely upon obtaining a uniform depression of the mercurial column, in different experiments made in atmospheres of uniform rarefaction, and whether slight differences in the composition of the gun-cotton would be indicated, with sufficient accuracy, by a corre­sponding difference in the volume of gas disengaged, or in the depression of the mercury. I found that, provided the mechanical condition of the gun-cotton, and its position with reference to the source of heat, were in all instances the same, the indications furnished by these experiments were sufficiently accurate for practical purposes. Each experiment was made with fifteen grains of gun-cotton, which were wrapped compactly round the platinum wire; the apparatus was exhausted until the column of mercury was raised to a height varying from 29 inches to 29·5 inches. The flash which accompanied the deflagration of the gun-cotton was apparently similar to that observed upon its ignition in open air ; but it was noticed that an interval of time always occurred between the first application of heat (or incandescence of the wire) and the flashing of the gun-cotton, and that during this interval there was a very perceptible fall of the column of mercury. On several occasions, when the gun-cotton, in the form of “roving,” or loosely twisted strand, was only laid over the wire, so that it hung down on either side, the red-hot wire simply cut it into two pieces, which fell to the bottom of the exhausted vessel, without continuing to burn. As these results appeared to indicate that the effects of heat upon gun-cotton, in a highly rarefied atmosphere, differed importantly from those observed under ordinary circumstances, or in a very imperfect va­cuum, a series of experiments, under variously modified conditions, was instituted, of which the following are the most important.

Numerical Analysis on Thermal Deformation of Linear Motor in Chip Mounter

2011 ◽  
Author(s):  
Kang-Woo Joo ◽  
Kwang-Sun Kim ◽  
Jun-Young Kim ◽  
Hee-Rak Beom
Keyword(s):  
Thermal Deformation ◽  
Linear Motor ◽  
Ball Screw ◽  
Heat Transfer Analysis ◽  
Semiconductor Chip ◽  
Research Activities ◽  
And Performance ◽  
Stress And Deformation ◽  
Electro Magnetic ◽  
Semiconductor Chips

In the semiconductor chip mounting process, the size of semiconductor chips is decreasing, while the number of mounting the chips per time are increasing, and this trend is being accelerated. The research activities to develop the chip mounters, which are able to mount rapidly and accurately, have been needed in the industry. With this background, the linear motor in the chip mounters has been an important part. The electro-magnetic type linear motor has many advantages such as direct linear reciprocating motion being compared with the rotary motor and the ball screw type linear motor. However, the electro-magnetic linear motor has thermal problems. These problems affect life and performance of motor and bring out the other problems such as thermal stress and deformation. The heat transfer analysis is difficult to solve thermal problems because the moving and fixed parts coexist. The trial & error methods have been therefore used under majority of cases. In this paper, we investigated the thermal deformation problems of linear motor in a chip mounter and the optimized parameters to design the motion parts of electro-magnetic linear motor were obtained.

Mathematical Notes by Professor Tait (2.) On the Equipotential Surfaces for a Straight Wire

1875 ◽  
Vol 8 ◽  
pp. 443-443
Keyword(s):  
Natural Philosophy ◽  
Line Density ◽  
Straight Wire ◽  
Equipotential Surfaces ◽  
The Wire ◽  
Image Position

Some results given in Vol. I. of Thomson and Tait's Natural Philosophy may be much more simply obtained by calculating the potential of a wire rather than its attraction. That potential is easily found aswhere c is the length of the wire, ρ its line density, r1 and r2 the distances of its ends from the point at which the potential is to be found.

Electroviscous forces on a charged particle suspended in a flowing liquid

1997 ◽  
Vol 338 ◽  
pp. 1-34 ◽  
Author(s):  
R. G. COX
Keyword(s):  
Particle Size ◽  
Physical Mechanism ◽  
Aqueous Electrolyte ◽  
Complete Agreement ◽  
Dominant Contribution ◽  
General Shape ◽  
Flowing Liquid ◽  
Polar Fluid ◽  
Double Layer Thickness ◽  
Made In

The force on a charged solid particle (of general shape) suspended in a flowing polar fluid (e.g. an aqueous electrolyte solution) in the presence of a solid bounding wall (of general shape) is obtained for the situation in which the electrical double-layer thickness is very much smaller than the particle size (and the distance between particle and wall). The very general results so obtained are applied to the sedimentation of a charged spherical particle in an unbounded polar fluid (with no walls present) for which the drag force is found to be in complete agreement with Ohshima et al. (1984). However, there is disagreement between the present results and those obtained in a number of published papers owing to incorrect assumptions being made in the latter as to what physical mechanism gives rise to the dominant contribution to the electroviscous force on the particle.

scholarly journals Revisiting Parameters of Bioinspired Behavior Models in Group Foraging Modeling

2020 ◽  
pp. 79-103
Author(s):  
Alexander Malyshev ◽  
Evgenii Burgov
Keyword(s):  
Feeding Behavior ◽  
Experimental Basis ◽  
Group Foraging ◽  
Quality Estimation ◽  
Finite State ◽  
Complex Test ◽  
Series Of Experiments ◽  
Basic Behavior ◽  
Behavior Models ◽  
Made In

Using bioinspired models and methods is one of approaches for solving tasks of swarm robotics. In this paper one of such tasks, modeling of foraging, and it’s solving by creating analogues of social structures of ants and models of feeding behavior are considered. The most important characteristics of ants’ colonies for modeling were defined – individuals number in society and it’s structure, workers’ speed, a communication distance and working area size. Besides, existing experimental basis (a group of robots and a polygon) was estimated for a usage as a hardware platform for experiments. Several models of feeding behavior were considered: a model without foragers’ functions differentiation and a model with differentiation on active and passive ones. Active foragers look for resources by themselves, then they involve passive foragers; passive foragers are settled on a base, while are not involved in harvesting. A set of finite state machines describe the behavior of agents: basic automatons (provide basic behavior functions) and a meta- automaton, that switches with some conditions an execution of basic automatons. Basic movements were tested on experimental basis. A complex test of models were conducted in a simulation program Kvorum. An analogue of real polygon was made in the program. Modeling consists of series of experiments for every model in which agents must harvest resources. Series differ from each other by number of agents. For models’ quality estimation a ratio of received energy to average obtaining time. Experiments settle that model with functions differentiation works more effective.

scholarly journals I. Experiments on the discharge of Leyden jars

1892 ◽  
Vol 50 (302-307) ◽  
pp. 2-39 ◽  
Keyword(s):  
Alternative Path ◽  
Series Of Experiments ◽  
Made In

The following experiments among others were made in the course of 1888, beginning in February of that year. A brief account of the early experiments, with some of the deductions from them, was given in a couple of lectures to the Society of Arts in March, 1888, on Lightning Conductors; and in the ‘ Electrician,’ vols. 21, 22, 23, under the same title, a number of others were published at length, viz., the series of experiments relating to "the alternative path."

scholarly journals VI. The effect of hydrogen on the discharge of negative electricity from hot platinum

1908 ◽  
Vol 208 (427-440) ◽  
pp. 247-273 ◽  
Keyword(s):  
Surface Layer ◽  
The State ◽  
Great Length ◽  
Series Of Experiments ◽  
The Wire

The effect of hydrogen on the discharge of negative electricity from hot platinum was examined by the writer in 1903 (‘Phil. Trans.,’ A, 352, vol. 202, 1903); it was found to produce a very large increase in the current carried by the discharge. At pressures below 0·1 millim. of mercury the leak was found to increase with the pressure and to fall when the pressure was reduced. The experiments in the paper just referred to were all done with nearly new platinum wires which had not been heated in the gas for any great length of time, because it was known that long continued heating caused the wire to disintegrate, its surface becoming covered with a network of cracks. The present paper contains an account of a series of experiments in which wires were heated for long periods in hydrogen, so that any gradual changes in the effect of the hydrogen could be observed. It appears that continued heating in hydrogen alters the character of the effects observed, so that the behaviour of an old wire may be very different from that of a new one. In the previous paper I suggested that the effect of hydrogen was due to the presence of hydrogen in the surface layer of the platinum, and this view appeared to be supported by the facts. Professor O. W. Richardson (‘Phil. Trans.,’ A, 413, vol. 207, 1906) puts forward a different theory, viz., that the hydrogen alters the state of the platinum, so that the effect may remain even after the removal of all the hydrogen.

The Mexican Government and the Mission Indians of Upper California, 1821–1835

1965 ◽  
Vol 21 (04) ◽  
pp. 335-362
Author(s):  
C. Alan Hutchinson
Keyword(s):  
California Indians ◽  
Las Casas ◽  
Bartolome De Las Casas ◽  
Mexican Government ◽  
Series Of Experiments ◽  
The Government ◽  
New Nation ◽  
White Settlers ◽  
California Mission ◽  
Made In

The Newly independent government of Mexico became concerned in 1821 about the lack of progress made by the Franciscans in preparing the California mission Indians to take their place in the new nation. The government feared that Upper California might well be lost to the encroachments of the Russians or the Americans if it were not settled by a thriving community of Mexican citizens able to exploit its great natural resources. Influenced by the new egalitarian and humanitarian concepts of the day, the authorities felt that the mission Indians were more like serfs than citizens. Unimpressed by the arguments of the experienced Franciscan Fathers that the Indians would either revert to their wild life in the hills or be enslaved by the white settlers if they were prematurely released from the missions, the government decided to instigate a series of experiments, reminiscent of those made in the days of Father Bartolomé de las Casas, to see what actually would happen. A program was begun involving extensive research in the culture and civilization of the California Indians.

scholarly journals On the production of transient electric currents in iron and steel conductors by twisting them when magnetised, or by magnetising them when twisted

1883 ◽  
Vol 36 (228-231) ◽  
pp. 117-135 ◽  
Keyword(s):  
Electromotive Force ◽  
Longitudinal Component ◽  
Iron And Steel ◽  
Iron Wire ◽  
Direct Observations ◽  
The Wire ◽  
Effects Of Stress ◽  
Direct Investigation ◽  
Component Parallel ◽  
Made In

1. A chance observation, made in the summer of 1881, drew my attention to the fact that when the ends of an iron wire are connected to the terminals of a galvanometer, a transient current will be observed if the wire he suddenly magnetised while it is held in a state of torsion, or suddenly twisted whilst in a state of longitudinal magnetisation. Further inquiry showed that these currents are satisfactorily explainable by reference to the results of more direct observations which have been made on the effects of stress on magnetism. They present, however, certain features of interest, and the examination of them, of which a condensed account is given below, may form a useful supplement to any direct investigation of the effects of stress on magnetic susceptibility and residual magnetism. 2. A straight, moderately soft, well-annealed iron wire, 1 millim. in diameter and 34 centims. long, was placed horizontally in an E. W. position, with one end securely fixed and the other held by a twisting arm, by which any desired amount of torsion might be applied. The twisting arm was provided with a pointer, which travelled over a graduated circular dial. The ends of the wire were connected by long leading wires to a Thomson’s mirror galvanometer of 0·25 ohm resistance, with a heavy mirror, which made it fairly suitable for ballistic work. Round the iron wire was a magnetising solenoid of 660 turns, 31 centims. long, in two layers, wound so as to have no longitudinal component parallel to the wire. In circuit with the solenoid was a single large Daniell’s cell and a reversing key. The resistance of this circuit was 1·36 ohms and, if we assume the electromotive force of the cell to have been 1 volt, the magnetising force was therefore 4 π x 660/31 x 1 x 10 8 /1·36 x 10 9 = 20 c. g. s. units very nearly.

scholarly journals III. A description of an extensive series of the water battery; with an account of some experiments made in order to test the relation of the electrical and the chemical actions which take place before and after completion of the voltaic circuit

1844 ◽  
Vol 134 ◽  
pp. 39-52
Keyword(s):  
Royal Society ◽  
Point Of View ◽  
Before And After ◽  
Series Of Experiments ◽  
Negative Facts ◽  
Made In

1. In a paper, which I communicated to the Royal Society in 1839, and which was honoured by insertion in the Transactions of the following year, I described a series of experiments made with some powerful voltaic batteries, for the purpose of determining the possibility of obtaining a spark before the completion of the voltaic circuit. I was therein enabled to establish a few facts respecting polar tension, or rather respecting the absence of any notable degree of it in the batteries I described; for instance, I proved that, with 320 series of Professor Daniell’s constant battery, polar tension was not evinced adequate to the striking distance of 1/5000 th of an inch; nor was I more successful in obtaining it with a water battery of 1024 series, constructed by the same gentleman. I also stated that, according to the present theoretical views of the action of the voltaic battery, with the apparatus I then used, it ought to have taken place; and that, if by a still more powerful apparatus it could not be obtained, the theory must, in some way or other, be incorrect. 2. The preceding negative facts are not without their value in a scientific point of view; they show us, at least, a certain limit within which the anticipated effects could not be obtained. At the same time I could not fail to admit that they were anything but conclusive, as to the actual question of the possibility of obtaining the spark before the circuit was completed. That I am justified in calling the spark, under such circumstances, an anticipated effect, may be fairly assumed, because every electrician is aware that the terminals of a voltaic series invariably evince a certain amount of tension and as spark is but a consequence of tension exalted to a maximum, it is only fair to anticipate that, by increasing the tension, it would be obtained.

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