Showing papers in "Ire Transactions on Product Engineering and Production in 1961"

The Application of Thermoelectric Spot Cooling to Electronic Equipment

Abstract: Summary Recent developments in the construction of thermoelectric coolers have resulted in improved coolers suitable for use in electronic equipment. The continual effort to improve the techniques of cooling electronic equipment led to the investigation of thermoelectric spot cooling of temperature-limiting component parts located within local areas of an electronic equipment. The investigation consisted of the evaluation and application of nine spot coolers constructed to specifications determined by an analysis. Thermal evaluation of the nine spot coolers showed that each spot cooler either met or exceeded the design requirement of pumping 5 w over a 30°C temperature difference. The coefficient of performance exceeded 0.5 for each of the spot coolers operated under the design condition. In addition to the satisfactory thermal performance, a spot cooler passed the mechanical shock and vibration requirements for satellite equipments used in Project Mercury. The information on spot cooler thermal performance was employed in an analytical application of spot cooling to a free-convection and radiation-cooled equipment and a forced-convection-cooled equipment. The results indicate that free-convection - and radiationcooled equipment can be operated in higher temperature environments with spot cooling; moreover, the cooling requirements for forced-convection-cooled equipment can be reduced.

Value Engineering and Product Engineering

Abstract: Value Engineering is coming of age° In the hands of experienced product engineers it can grow into a truly professional tool for improving the competitive position of a company. It applies the precise techniques of science and engineering to those areas of evaluation, programming, and decision-making which have heretofore been governed by intuition. In estimating, bidding, and scheduling, Value Engineering saves not only money but also elapsed time. In design, development and production, it seeks the best ratio between desirable qualities and their cost in available resources. This paper will illustrate how Value Engineering can be utilized within the conventional engineering disciplines to provide the quantitative data necessary for better balanced specifications, for reducing areas of uncertainty in product planning, and for better decisions in both product design and program management.

Metal Diffusion Techniques and Class Sealing Problems in the Electron Tube Industry

Abstract: Summary-- This paper deals with early techniques of chrome diffusion and the more recent methods of chromizing of metals. Historical applications of the process as applied to certain glass sealing metals, its effect on the coefficient of thermal expansion and the interface between glass and metal, as well as proper seal geometry, are discussed. Precleaning, oxide formation, glass application, seal types, and postremoval of the oxide are explained.

Analytical Dollar Tradeoffs for Development of Electronic Equipment

Abstract: This paper presents reasons for the importance of formal documented analytical calculations regarding tradeoff decisions in the design and evolution of electronic and electro-mechanical equipment. This paper offers several quantitative tradeoff factors which convert equipment design parameters to equivalent dollar penalties and values.

Investigation of Production Requirements for Solderless Wire Wrapped Electrical Connections

Abstract: A solderless wire wrapped electrical connection consists of tightly wrapping solid bare wire around a stationary terminal to produce a durable pressure connection. Properly made, the wrapped connection is a permanent, reliable electrical connection that can be produced faster than soldered connections. The elimination of solder and heat detriments are distinct advantages over the soldered connection. Wire wrapping lends itself to automation, and connections can be easily made on closely spaced terminals. While it is a mechanically strong connection, an individual connection is easily removed, simplifying modification and repair. However, this may be less of an advantage in multi-level wrapping. The increase in complexity of electronic equipment during the last decade has presented industry with some unique production problems. Not the least of these has been the great increase in the number of electrical connections. The need for speed in making this many connections, without decreasing quality, prompted IBM to expend considerable effort in identifying the variables that affect solderless wire wrapping connections in order to define the controls needed in production. At the present time, these connections are widely used by IBM in both commercial and military applications, and over 100 million solderless wrapped connections were made by IBM in 1960. The use of the solderless wrapped connection has grown steadily since the Bell System first made the new connection public in 1952. Extensive laboratory tests, performed principally byBell Laboratories, and field experience have verified the reliability of the connection. This paper describes the effect of the variables involved in the wire wrapping process which were determined from the results of laboratory tests and manufacturing experience and the process controls required to assure the quality and reliability of production connections. To meet process requirements consistently, the many variables inherent in the solderless wire wrapping process must be considered. These variables will be discussed under the major variable factors involved in the process.

A Dot Component Packaging System for Electronics

Abstract: Summary - A new packaging concept for microelectronics and its application to a digital system are presented. The concept utilizes the new Dot components mounted in ceramic wafers. Dot components are disks 0.03-in thick with a diameter as small as 0.05-in. Connections to components are made by multi-layer deposition techniques; and connections to wafer modules, by a novel pressure connection method. A unique and compact heat transfer scheme is described. The design example contains 2260 of the smallest Dot components in an approximately 1. 25-in cube. The component density of the package (including all thermal, interconnection, and structural provisions) is 1,960,000 per cubic foot (1130 per cubic inch). The package provides excellent temperature control for the components and is sufficiently rugged to withstand space environments. A photograph of model hardware is shown.

High Density Electronic Packaging via Welded Honeycomb Structures

Abstract: A system of packaging based on the Sperry "Honeycomb" concept is described which attempts to resolve the major problems associated with other current packaging schemes. The paper reviewsthe considerations of high density welded three-dimensional packaging and some advantages and disadvantages of the popular concepts. This method is particularly applicable to develop programs since it permits evaluationo the circuit prior to final encapsulation. The paper details a typical circuit package from its original circuit schematic through packaging layout, assembly, testing and final encapsulation. It also shows how the packaging method can be adapted to permit replacement of components if required.

Digital Microelectronic Equipment Problems and Potentials

Abstract: Major problems encountered in the design of a micromodule digital computer (MICROPAC) for tactical operation within the Field Army are described and solutions presented. Such problems include module heat transfer, interconnection of modules and module assemblies and selection of module assembly size and configuration. The utilization of the circuitry booklet configuration for module mounting, interconnection and cooling is described. It is shown that reasonable air cooling will provide adequate heat transfer for several thousand modules dissipating an average of 120 milliwatts per module. The quantitative dependence of over-all circuitry packaging density upon connector pin per module requirements, type of booklet and harness wiring, booklet size and configuration, etc. is presented in analytical form. It is concluded that an over-all circuitry section (including connectors, backplane wiring, etc.) packaging density of 150,000 components per cubic foot is obtainable by the utilization of micromodules with an average packaging density of slightly less than 500,000 components per cubic foot. The extent to which the equipment designer and user will achieve their objectives by the application of micromodules to military digital equipment is discussed. It is indicated that more than 60,000 modules (each containing such logical elements as a flip-flop, two logic gates or equivalent) can be mounted, interconnected and adequately cooled within a volume occupied by a 6-foot rack. This dramatic reduction of volume (and weight) is accompanied by a corresponding decrease in the equipment support or overhead cost per module.

Transportation and Packaging Techniques to Improve Realiability

Abstract: An outline is presented of probable environments to be expected in shipping electronic equipment by the following: 1. Aircraft transport vehicles 2. Railroad 3. Trucks 4. Ships The environmental engineering data is based upon previous studies and military governing specifications. Orders of magnitude are given as yardsticks for shock design inputs in terms of G level shock pulses, pulse shapes, pulse durations, population of pulses and direction of pulses. Test procedures to simulate environment shocks are described. Accelerated life test philosophy is defined. Similarly, orders of magnitude are given for low frequency vibration inputs as terms of cumulative cycles, frequencies, G levels and amplitude levels. Test procedures are briefly discussed. Discussion is included regarding electronic equipment resistance to environmental transportation shock and vibration. References are cited for the performance of rigorous analyses for determination of natural frequency and transmissibility. Recommendations are made for qualitative evaluation of electronic equipment resistance in shipping environments. Transmissibility across suspension system during shock and vibration excitation is discussed. Incompatibility between shock and vibration isolation is discussed.

The Product Engineer and the Magnetic Thin Film

Abstract: Magnetic thin films have great potential as memory elements in digital computers The properties of thin films are such that memories can be operated at speeds of the order of 100 nanoseconds or less, non-destructively in certain instances While the elements themselves show great promise, there are many problems attendant to their use, the solution of which must dome from experts in packaging techniques