Showing papers by "IBM published in 1969"

Some long‐run properties of geophysical records

Abstract: By preparing this book Chris Barton and Paul La Pointe have earned the gratitude of all geologists and students of fractals. I continue to belong to this second group, and Chris and Paul clearly have put me in a very special debt to them.

The Fast Fourier Transform and Its Applications

Abstract: The advent of the fast Fourier transform method has greatly extended our ability to implement Fourier methods on digital computers A description of the alogorithm and its programming is given here and followed by a theorem relating its operands, the finite sample sequences, to the continuous functions they often are intended to approximate An analysis of the error due to discrete sampling over finite ranges is given in terms of aliasing Procedures for computing Fourier integrals, convolutions and lagged products are outlined

The kinoform: a new wavefront reconstruction device

Abstract: A new, computer-generated, optical element called a kinoform is described. This device operates only on the phase of an incident wave and forms a single image by wavefront reconstruction without the unwanted diffraction orders characteristic of holograms. The kinoform is also more efficient in the use of spatial frequency potential and reconstruction energy and can be synthesized in considerably less computer time than the digital hologram.

Reliability of controlled collapse interconnections

Abstract: The use of solder pads to join multi-pad integrated circuit chips to modules provides a highly reliable, rugged interconnection technology. This paper reports some important aspects of the reliability evaluation that was carried out on the "controlled chip collapse" interconnection system developed by IBM. Included are an analysis of the mechanics of the system, a model to establish the relationship among differentt hermal fatigue testing conditions, and experimental verification of the model. In the course of this work, the chip failure rate of the interconnection as used in present designs was predicted to be better than 10-7%/1000 hours for the mechanism studied.

Computer-generated binary holograms

Abstract: Holograms synthesized by computer are used for constructing optical wavefronts from numerically specified objects. Elimination of the need for a physical object has made new applications possible, for example, three-dimensional computer output displays, synthetic prototypes for interferometric testing, and filters for various optical data processing operations. Our computer holograms differ from a normal hologram in that the transmittance is binary, yet they are able to construct general wavefronts and images efficiently and have several practical advantages over holograms with a continuous range of transmittance. Recent improvements that simplify the production of binary holograms and improve their performance are described and experimental work showing reconstruction of two- and three-dimensional images is presented.

Electron Spin Resonance in Amorphous Silicon, Germanium, and Silicon Carbide

Abstract: The $g$ values, line shapes, and linewidths of the ESR signals from within the bulk of amorphous silicon, germanium, and silicon carbide are found to be similar to those of the electron states observed in the surface regions of the corresponding crystalline forms. Discussion is given in terms of a microcrystalline model.

Controlled collapse reflow chip joining

Abstract: Solder reflow connection of semiconductor devices to substrates has been shown to be a reliable, effective, and readily automated technique. Rigid copper spheres, which remain rigid during solder reflow, have been used successfully for some timae as major element of the contact joint. However, to expand the capability of such joints to larger devices such as multiple-transistor chips in hybrid components, ductile metallic joining pads can be used on the devices instead of the copper spheres to reduce mechanical strains andp ermit multi-pad devices to make proper contactt o module lands during reflow. This paper describes a technique that prevents these solder pads from collapsing and permits large scale production. Termed "controlled collapse," the method is based on limiting the solderable area of the substrate lands and chip contact terminals so that surface tension in the molten pad and land solder supports the device until the joint solidifies. The result is a sturdy, testable connection of high reliability (bond strength30-50 gm, pilot-production yields exceeding 97%, predicted failure rate-based on laboratory tests-considerably lower than that of copper ball contacts). The process is economically adaptable to automation and offers considerable latitude in fabrication and control tolerances.

On the base-dependence of sets of numbers recognizable by finite automata

Abstract: It is known that the set of powers of two is recognizable by a finite automaton if the notational base used for representing numbers is itself a power of two but is unrecognizable in all other bases. On the other hand, the set of multiples of two is recognizable no matter what the notational base. It is shown that the latter situation is the exception, the former the rule: the only sets recognizable independently of base are those which are ultimately periodic; others, if recognizable at all, are recognizable only in bases which are powers of some fixed positive integer.

Electrical Properties of Some Titanium Oxides

Abstract: Electrical conductivity, differential thermal analysis, ac Hall effect, and x-ray diffraction measurements were used to investigate the low-temperature behavior of flux-grown single crystals of the titanium oxides. Monoclinic ${\mathrm{Ti}}_{3}$${\mathrm{O}}_{5}$ and the triclinic Magn\'eli phases ${\mathrm{Ti}}_{4}$${\mathrm{O}}_{7}$, ${\mathrm{Ti}}_{5}$${\mathrm{O}}_{9}$, and ${\mathrm{Ti}}_{6}$${\mathrm{O}}_{11}$ were studied---with the major effort devoted to ${\mathrm{Ti}}_{4}$${\mathrm{O}}_{7}$. The only known property of the Magn\'eli phases was the magnetic susceptibility, which was measured on polycrystalline samples. Several transitions, most of which correlate with previously reported magnetic susceptibility data, were found in these compounds. A semiconductor-to-metal transition occurs in ${\mathrm{Ti}}_{4}$${\mathrm{O}}_{7}$ at 149\ifmmode^\circ\else\textdegree\fi{}K, followed by a second transition at 125\ifmmode^\circ\else\textdegree\fi{}K which involves some structural rearrangement. The properties of these compounds are discussed in relation to existing theories for the transition-metal oxides. It is concluded that the observed properties are not adequately explained by these theories.

SLT device metallurgy and its monolithic extension

Abstract: The glass-passivated, face-down semiconductor chip joining technology employeidn IBM's SLT (Solid Logic Technology), has become not only a fundamental element in the hybrid circuitry of System/360 but also the basis for later metallurgical designs. The "flip-chip," copper ball terminal, solder reflow technique is comprehensively reviewed and a discussion is given of its extension, through the use of ductile, all-solder terminals, to monolithic applications.

Multiplet splitting of core-electron binding energies in transition-metal ions

Abstract: X-ray photoelectron spectra indicate core-electron binding-energy splittings of \ensuremath{\sim}6 eV for the $3s$ levels in Mn${\mathrm{F}}_{2}$, MnO, and Fe${\mathrm{F}}_{3}$, and less pronounced effects on the $3s$ levels in Mn${\mathrm{O}}_{2}$ and Fe metal. These splittings are considerably reduced from free-ion predictions but agree well with calculations for Mn in a cluster environment. The $3p$ multiplet splittings are shown to behave in a quantitatively different fashion.

Object code optimization

Abstract: Methods of analyzing the control flow and data flow of programs during compilation are applied to transforming the program to improve object time efficiency. Dominance relationships, indicating which statements are necessarily executed before others, are used to do global common expression elimination and loop identification. Implementation of these and other optimizations in OS/360 FORTRAN H are described.

Hourglass-shaped conductive connection through semiconductor structures

Abstract: An integrated semiconductor structure including the fabrication thereof, and more particularly, an improved means for interconnecting the two planar surfaces of a semiconductor wafer. To provide the electrically conductive interconnections through the wafer, a hole is etched, insulated, and metallized. Active or passive devices may be formed on either or both sides of the wafer and connected to a substrate by solder pads without the use of beam leads or flying lead bonding.

Real-Time Computation by n-Dimensional Iterative Arrays of Finite-State Machines

Abstract: An n-dimensional iterative array of finite-state machines is formally introduced as a real-time tape acceptor. The computational characteristics of iterative arrays are illuminated by establishing several results concerning the sets of tapes that they recognize. Intercommunication between machines in an array is characterized by specifying a stencil for the array. The computing capability of the array is preserved even if its stencil is reduced to a simple form in which machines communicate only with their nearest neighbors. An increase of computing speed by a constant factor k is defined by encoding k-length blocks of the input tapes, which reduces the lengths of the tapes by 1/k; the time available for computation is correspondingly reduced since the computation must be real time. The computation speed of iterative arrays can be increased by any constant factor k. Two examples of one-dimensional arrays are provided. The first accepts the set of palindromes; the second accepts the set of all tapes of the form ττ (for any tape τ). The latter set of tapes is not a context-free language; therefore, the sets of tapes accepted by iterative arrays are not all contained in the class of context-free languages. Conversely, the class of context-free languages is not contained in the class of sets of tapes accepted by iterative arrays. The sets of tapes accepted by iterative arrays are closed under the operations: union, intersection, and complement; therefore, they form a Boolean algebra. They are not closed under the reflection or concatenation-product operations.

Geometric optimization of controlled collapse interconnections

Abstract: This paper deals with the mechanical reliability of controlled collapse joints in modules subjected to the thermal fatigue conditions of machine usage. Particular emphasis is placed on design variability and how the shape and dimensions of the joint and chip affect reliability. A systematic technique is presented to optimize pad dimensions. A new experimental method to characterize chip-to-substrate interconnections-the torque test-is described and analyzed. Its applicability to design evaluation is discussed and representative data are analyzed. The relationship between torque test measurements and fatigue is discussed.

Flip chip module with non-uniform connector joints

Abstract: The interconnecting joints between a semiconductor chip and a substrate are not uniform, but differ in shape or material The difference results in different abilities to withstand shear stress and increases the device lifetime A volume differential causes a stress resistance differential in the interconnection joints

Data base task group report to the CODASYL programming language committee, October 1969

Abstract: This report has been prepared by the Data Base Task Group which is an ad hoc committee of the CODASYL Programming Language Committee. The report details the recommendation of the Data Base Task Group to its parent committee. It consists of a proposal for a Data Description Language and a Data Manipulation Language. The Data Description Language is a language for describing a database. The Data Manipulation Language is language which, when associated with the facilities of a host language such as COBOL, PL/1, ALGOL, JOVIAL, FORTRAN..., allows manipulation of databases described by the Data Description Language. The specification of separate Data Description and Data Manipulation Languages is significant in that it allows databases described by the Data Description Language to be independent of the host languages used for processing the data. Of course, for this to be possible, the host language processors must be able to interface with such independent descriptions of data.

The finite Fourier transform

Abstract: The finite Fourier transform of a finite sequence is defined and its elementary properties are developed. The convolution and term-by-term product operations are defined and their equivalent operations in transform space are given. A discussion of the transforms of stretched and sampled functions leads to a sampling theorem for finite sequences. Finally, these results are used to give a simple derivation of the fast Fourier transform algorithm.

Self-Coupling of a Two-Level System by a Mirror

Abstract: We discuss, from a classical as well as a quantum-mechanical point of view, the effect of the coupling of an excited two-level system with itself due to emission and absorption of electric-dipole radiation, the emitted radiation being reflected by a nearby mirror. Expressions familiar from resonance-scattering theory are found for the shift of the transition frequency and linewidth from their values in the absence of the mirror. This renormalization effect leads to spatial modulation in the transition frequency and width of the excited state due to its resonant interaction with itself via the radiation field reflected from the mirror. This formalism is applied to some recent experiments with monomolecular dye layers. The experimental values of the fluorescence lifetime are in good agreement with the theory for distances from 500 to 6000 \AA{}.

A fixed-point fast Fourier transform error analysis

Abstract: This paper contains an analysis of the fixed-point accuracy of the power of two, fast Fourier transform algorithm. This analysis leads to approximate upper and lower bounds on the root-mean-square error. Also included are the results of some accuracy experiments on a simulated fixed-point machine and their comparison with the error upper bound.

Flip chip module with non-uniform solder wettable areas on the substrate

Abstract: The interconnecting joints between a semiconductor chip and a substrate are non-uniform in shape. The joints are solder and have varying shapes due to varying sizes of the solder wettable regions on the substrate. Smaller solder wettable regions cause the solder connectors to increase chip substrate standoff thereby relieving the stress on the remaining joints.

Algorithms for the Simple Plant-Location Problem with Some Side Conditions

Abstract: The algorithms of this paper belong to the direct-search or implicit-enumeration type. They compare to the recently proposed algorithm of Efroymson and Ray, as does the mixed integer algorithm proposed by C. E. Lemke and the author to that of Land and Doig. The general plan of procedure is expected to be equally valid for the capacitated plant-location problem and for transshipment problems with fixed charges; with some of the proposed devices more important for these difficult problems than for the simple plant location problem. Considerable computational experience has been accumulated and is discussed at some length. It suggests that additional work on the construction of "adaptive" programs, matching algorithm to data structure, is desirable.

g Factor of the Two-Dimensional Interacting Electron Gas

Abstract: The $g$ factor of quasiparticle states near the Fermi energy in a two-dimensional electron gas with Coulomb interactions is calculated in a static approximation. It is argued that this quadiparticle $g$ factor, different from the free-electron $g=2.0023$, is the relevant quantity for spin splittings in experiments such as those on de Haas-van Alphen or magnetoconductivity oscillations, and, in particular, in experiments on electrons in silicon surface inversion layers. The $g$ factor observed in conduction-electron spin resonance, on the other hand, should be the bulk value of 1.99.

Fluid actuated contactor

Abstract: A constant impedance or impedance matched fluid actuated contactor for electrical components, especially integrated circuit semiconductor chips, is provided. The contactor has a flexible dielectric membrane, on one side of which is a resilient, electrically conductive ground plane. On the other side of the dielectric membrane is a plurality of electrically conductive lines adapted to contact the electrical component. The membrane is mounted on a pressure chamber, and a pressurized fluid is utilized to move the dielectric membrane and the electrically conductive lines carried thereon into contacting engagement with the electrical component.

Dynamic space-sharing in computer systems

Abstract: A formalization of relationships between space-sharing, program behavior, and processor efficiency in computer systems is presented. Concepts of value and cost of space allocation per task are defined and then value and cost are combined to develop a single parameter termed value per unit cost.The intent is to illustrate a possible analytic approach to the investigation of the problems of space-sharing and to demonstrate the method on sample problems.

Alkali Strontium‐Barium‐Lead Niobate Systems with a Tungsten Bronze Structure: Crystallographic Properties and Curie Points

Abstract: Crystallographic parameters, Curie points, and freezing temperatures are presented for a series of A+A22+Nb5O15 compositions with tungsten bronze-related structures, where A+=Na, K, or Rb, and A2+=Sr or Ba. Results are also reported for bronze solid solutions in the systems KNbO3-PbNb2O6, K(Sr-Ba)2Nb5O15, K(Ba-Pb)2Nb5O15, K(Sr-Pb)2Nb5O15, and (KSr2-K2La)Nb5O15. On the basis of these data, an empirical relation is shown between the ferroelectric transition temperature, Tc, and axial ratio °10 co/a0. The Tc vs °10 c0/a0 curve for compositions with polar axes perpendicular to [00l] has a negative slope, whereas that for compositions with polar axes parallel to [00l] has a positive slope of about the same magnitude. These results are compared with measurements of the temperature dependence of c0/a0 for KSrPbNb5O15, and KBa2Nb5O15; the latter is discussed in terms of the Devonshire free energy theory.