Chip Type Research Articles

The learning curve in the production of semiconductor memory chips

The relevance of the learning curve in the production of semiconductor memory chips is examined. It is shown that the learning curve differs across quite similar products such as distinct types of memory chips. On the other hand, the learning curve does not show significant variation over successive generations of the same type of memory chip. it is then shown thatthe interpretation given to the heterogeneity of learning by the effects across chip types, and especially the importance of economies of scale, is consistent with some stylized facts from the industry.

A new placement level wirability estimate with measurements

An extension of the wirability estimate concept to master slice placement is presented. This estimate is usable on individual circuits, produces detailed wire requirement maps, but requires target designs to be at least partially placed. The main innovation is the discovery of an outer rectangle estimate that separates basic wire requirements from routing details. The estimate averages wires within one chip but is inapplicable to chip type wire space modeling. Steiner tree net decomposition, the half perimeter wire length estimate, and potential wire requirement reduction from a third metal layer are evaluated.

A wafer design problem in semiconductor manufacturing for reliable customer service

The authors present models that explicitly take account of yield losses and show how available chip sites should be allocated among various types of chips to meet the demand of a set with the maximum probability. A key result is that the proportion of sites allocated to each chip type varies with the total number of available sites. The allocation model also provides a tradeoff curve between the total number of chip sites assigned for the production of a set and the highest attainable level of confidence in meeting the demand; this is valuable when more than one set is competing for the same resources. The influence of wafer loss and rework on the determination of job size is considered. The models presented here are particularly useful when reliable delivery of a set of chips by an impending due date is of prime concern and the fabrication line is congested.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A new parallel sorting approach with sorting memory module

A new approach to accelerating parallel sorting processes is introduced in this paper. This approach involves the design of a new type of memory chip with sorting functions. This type of sorting memory chip is feasible with today's VLSI techniques. A memory module organizing several sorting memory chips associated with additional ECL or TTL control logic circuits is also presented. Using the sorting memory modules in a shared memory parallel processor machine, parallel sorting algorithms such as the column sort method can reduce the row access time significantly and avoid data collisions in the interconnection network. Experimental simulation results on the practical speedup achieved and the memory utilization for the proposed approach are described.

Future very-large-scale integration technology

Abstract Emerging technologies for very-large-scale integration (VLSI) process and device architecture are discussed. A new domain of submicron technology for 16 Mbits and beyond has recently been developed on the basis of unique surface chemistry on a cooled substrate in the temperature range from −20 to −130 °C. Reactive ion etching at low temperatures has dramatically improved the anisotropy, pattern shift and selectivity. Also, low temperature remote plasma chemical vapour deposition (CVD) has achieved complete planarization of device surfaces. Pattern projection of thin films has become possible by using excimer-laser-induced cryogenic CVD. All these findings have indicated the significant importance of controlling adsorbate-solid surface interactions in future VLSI process technology. As for device architecture a new type of silicon chip such as a three-dimensional optically coupled common memory will be developed in addition to the conventional high density VLSI memories.

4703483 Chip on chip type integrated circuit device

4703483 Chip on chip type integrated circuit device

Modelling the Catastrophic Shear Type of Chip When Machining Stainless Steel

When machining materials such as stainless steel and titanium the removed chip is characterized by a serrated (saw-tooth) outer surface and large cyclic variations in macrostrain within the chip. The present paper presents a model for the process producing such chips. The model is shown to represent accurately experimental results derived from cine films and photomicrographs of the chip formation process obtained when maching stainless steel.

Some observations on surface damage during machining of a bearing bronze

The effect of the tool rake angle, depth of cut (feed), tool wear land length and cutting speed on the nature of the surface generated in machining a bearing bronze (free machining) under dry unlubricated orthogonal conditions was determined. Machined workpieces were examined with an optical microscope and a scanning electron microscope equipped with an energydispersive X-ray analysis system. The surface roughness was determined with a profilometer. The results of the investigation show that during machining considerable surface damage in a wide variety of forms is produced. The intensity of the surface damage and the surface roughness increases with an increase in feed rate, an increase in rake angle and an increase in tool wear land length, but is independent of the cutting speed. The results also show that lead is readily lost from surface cavities and is deposited on the rake and flank faces of the cutting tool as a smeared layer. In addition, lead globules were found on the tool holder, the freshly machined workpiece surface and other regions close to the tool cutting action. The results are interpreted in terms of the type of chip produced, the stress concentrations associated with the presence of second-phase particles (lead) and the nature of the interaction between the tool cutting edge and the workpiece.

Essências papeleiras de reflorestamento: 8 madeiras nativas da Amazônia.

Relatam-se. os ensaios de laboratório sobre 8 espécies florestais amazônicas,visando a sua utilização como Essências Papeleiras de Reflorestamento. Inicialmente,analisam-se as suas distuibuições geográficas na Amazônia brasileira, bem como mencionam-se as informacões silviculturais sobre elas existentes. Descrevem-se os ensaios realizados sobre a composição química, densidade, classificação dos cavacos e picagem das madeiras. Relatam-se as metodologias empregadas na fabricação de pastas químicas alcalinas e polpas semiquímicas NSSC. Descrevem—se os vários métodos utilizados nos alvejamentos dessas pastas. Citam-se as metodologias empregadas para a caracterização físico-mecânicas dos papéis e cartões fabricados dessas pastas. Discutem-se os resultados dos ensaios. Fazem-se várias influências sobre eles . Conclui-se que as espécies pesquisadas são recomedodas a nível de pesquisa de Laboratório como Estância Papeleira para Reflotestamento.

Highlights of the DARPA Advanced Machining Research Program

Results of a four-year Advanced Machining Research Program (AMRP) to provide a science base for faster metal removal through high-speed machining (HSM), high-throughput machining (HTM) and laser-assisted machining (LAM) are presented. Emphasis was placed on turning and milling of aluminum-, nickel-base-, titanium-, and ferrous alloys. Experimental cutting speeds ranged from 0.0013 smm (0.004 sfpm) to 24,500 smm (80,000 sfpm). Chip formation in HSM is found to be associated with the formation of either a continuous, ribbon-like chip or a segmental (or shear-localized) chip. The former is favored by good thermal properties, low hardness, and fcc/bcc crystal structures, e.g., aluminum alloys and soft carbon steels, while the latter is favored by poor thermal properties, hcp structure, and high hardness, e.g., titanium alloys, nickel base superalloys, and hardened alloy steels. Mathematical models were developed to describe the primary features of chip formation in HSM. At ultra-high speed machining (UHSM) speeds, chip type does not change with speed nor does tool wear. However, at even moderately high speeds, tool wear is still the limiting factor when machining titanium alloys, superalloys, and special steels. Tool life and productivity can be increased significantly for special applications using two novel cutting tool concepts – ledge and rotary. With ledge inserts, titanium alloys can be machined (turning and face milling) five times faster than conventional, with long tool life (~ 30 min) and cost savings up to 78 percent. A stiffened rotary tool has yielded a tool life improvement of twenty times in turning Inconel 718 and about six times when machining titanium 6A1-4V. Significantly increased metal removal rates (up to 50 in.3/min on Inconel 718 and Ti 6A1-4V) have been achieved on a rigid, high-power precision lathe. Continuous wave CO2 LAM, though conceptually feasible, limits the opportunities to manufacture DOD components due to poor adsorption (~ 10 percent) together with high capital equipment and operating costs. Pulse LAM shows greater promise, especially if new laser source concepts such as face pump lasers are considered. Economic modeling has enabled assessment of HSM and LAM developments. Aluminum HSM has been demonstrated in a production environment and substantial payoffs are indicated in airframe applications.

A new cloth inductor using amorphous fiber

A new cloth inductor using amorphous magnetic fibers is proposed and discussed on its design and characteristics along with experimental results. The cloth inductor realizes larger inductance per unit volume than that of chip type inductor and therefore is able to be miniaturized. Furthermore, an isolating transformer in cloth structure is fabricated, which acts in the frequency range up to 10 MHz.

Residual stress distribution in machining an annealed bearing bronze

The residual stress distribution in the surface region of workpieces of a bearing bronze that is machined under unlubricated, orthogonal conditions is determined using a deflection etching technique. The residual stress at the surface is low (compressive) and increases with an increase in depth beneath the machined surface to a maximum (tensile) then decreases continuously with a further increase in depth eventually becoming vanishingly small. The peak residual stress and depth of the stressed region increase with an increase in cutting speed, an increase in feed rate and an increase in tool rake angle but are independent of tool wear land length. The results of the investigation are interpreted qualitatively in terms of the type of chip produced and the variation of the thickness of the deformed surface region with cutting conditions.

Precision internal threading of stainless steel

Analysis has shown that vibration cutting is a suitable process for production of internal screw threads in thin stainless steel cylinders. A precision vibration internal threading lathe has been developed. Experiments were carried out with this lathe to investigate the tool life, chip type, accuracy of machined thread etc. The main results obtained by experiments are: (1) the chips formed by this vibration cutting are unoxidized, white-grey, flow type chips; (2) a smooth machined flank is produced which has an iridescent surface; (3) the desired sharp profile of the internal thread can be machined; (4) the relation between tool wear and cutting lengths was investigated; (5) by this process and lathe, it is possible to thread 10 000 pieces per tool. This is a 200-fold extension of tool life, compared with 40–50 pieces in conventional cutting. The vibration internal threading machine has been used in mass production tests, and the above results confirmed on about 500 000 work-pieces.

Surface Integrity in Machining Solution-Treated and Aged 2024-Aluminum Alloy, Using Natural and Controlled Contact Length Tools. Part I—Unlubricated Conditions

The effects of cutting speed, chip-tool contact length and tool surface finish on the surface integrity of a solution-treated and aged 2024-Aluminum alloy, that is machined under dry, orthogonal conditions are investigated. The surface region of machined workpieces is examined using a wide variety of diagnostic techniques. In addition, tool forces are measured and both the cutting geometry and cutting temperatures are calculated. The results of the investigation show that a wide variety of geometrical surface features are generated that contribute to the natural surface roughness. The results also show that a plastically deformed surface region is generated that contains variations in hardness, microstructure and residual strain. The results of the investigation are interpreted in terms of the type of chip produced, formation of the built-up edge, the mechanics and thermodynamics of the cutting process and the interaction between the tool nose region and freshly machined workpiece surface.

Surface Integrity in Machining Solution-Treated and Aged 2024-Aluminum Alloy, Using Natural and Controlled Contact Length Tools. Part II—Lubricated Conditions

The effects of cutting speed, chip-tool contact length, and tool surface finish on the surface integrity of solution-treated and aged 2024-aluminum alloy, that is machined under lubricated orthogonal conditions are investigated. The surface region of machined workpieces is examined using a variety of diagnostic techniques. In addition, tool forces are measured and the cutting geometry is determined. The results show that a variety of geometrical surface features are generated that contribute to the natural surface roughness, and that a plastically deformed surface region is generated that contains variations in hardness, microstructure, and residual plastic strain. The results are interpreted in terms of the type of chip produced, the mechanics and thermodynamics of the cutting process and the lubricating action of cutting fluids. When the results of the investigation are compared with similar results derived under nonlubricated conditions, it is found that at low cutting speeds application of a lubricant produces a reduction in tool forces, power consumption, surface roughness, surface defects, and subsurface deformation, whereas at high cutting speeds application of a lubricant has little influence on the cutting process.

Planar multijunction high voltage solar cell chip

Integrated circuit technology has been successfully developed to design and fabricate a new type of small area planar multijunction high voltage solar cell chip for concentrated sunlight applications. Each of these 1×1 cm solar cell chips was a monolithic device consisting of six internally series interconnected unit cells, fabricated on 75 μm thick p-type single crystal silicon substrate. Each chip consisted of 1.42×9.63 mm n+/p collecting junctions on the back of the wafer. The illuminated front surface area was divided into 0.3 μm deep n+ regions which form front surface field regions corresponding to the n+/p unit cells positioned beneath. A five photomask level photolithographic process together with a standard microelectronics batch process technique was employed to construct the PMJ solar cell chip. The open circuit voltage of the solar cell chip increased rapidly with illumination up to about 4 AMl suns, and then began to saturate at the sum of the individual unit cell voltages of 3.5 V above 4 AMl suns. A short circuit current density per unit cell of 300 mA/cm2 at 20 AMl suns was observed. This low value is attributed to a low minority carrier diffusion length in the base region of the solar cell chip. The suggested process modifications should significantly increase the device efficiency.

Zones and boundaries between different types of chip

The machining conditions, speed, feed and depth of cut, as well as the mechanical properties of the machined parts have a marked influence on the mechanics of chip formation. Different types of chip may be produced, namely continuous, partially discontinuous, discontinuous or continuous with either a serrated or a built-up edge. In the present work three different materials, aluminium, mild steel and brass, were machined orthogonally under different cutting conditions. Different types of chip were observed and the variations in the zones of and in the boundaries between types of chip with the machining conditions were determined for the materials used. An analysis for changing from one type of chip to another type is given, and recommended cutting conditions are reported for the different materials tested according to the type of chip produced. The cutting force components were measured in order to determine the mean coefficient of friction on the tool face and to determine the relation between this coefficient of friction and the type of chip produced.

Fracture phenomena of high polymers in cutting

Abstract Many products made from high polymers are mainly obtained by means of molding techniques. A cutting process for high polymeric materials has recently been developed for the field of precision machine and electronic parts production. The mechanism of chip formation during cutting is influenced by cutting conditions and Theological behavior of the materials. In other words, the fracture phenomena are controlled by cutting conditions and work material behavior. In this paper, the relation between the cutting conditions and the types of chips formed are classified roughly into continuous and discontinuous type chip. Moreover, these may be classified into six types; cleavage, flow, shear, shear with crack, tear, and crack type. Fracture phenomena giving a peculiar type of chip, such as cleavage type or crack type, are also discussed, as is the influence of cutting speed on the chip formation.

Some aspects of chip control in profile boring

The problems associated with chip removal during profile boring are highlighted and the effect of using a chip curler pad on the rake face of ISO triangular inserts investigated. The chip types obtained by varying the geometry of the chip curler pads are observed and the conditions under which a forward flowing continuous helical chip is obtained are determined. This chip type is of use when machining ‘through holes’ where the chip can flow along the bore in advance of the boring bar, through the hollow lathe spindle to be collected at the rear of the lathe. This method of chip collection simplifies chip removal problems in profile boring. Some illustrative examples of the effect of cutting conditions on chip radius and pitch of the chip helix are given and the chip form is shown to depend on the workpiece geometry in addition to the Cutting tool/chip curler geometry.

Electronic musical instrument using plural programmable divider circuits

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