bluuebunny/crossref_metadata_2025 huggingface dataset:
Special library integrates cutting‐edge technology: the 3M™ Digital Identification System
Authors: Yorkovich John
Published: February 2008

Routine tasks, such as transactions at the bank, grocery store and gas station, are becoming more and more automated, making daily activities more efficient. 3M Library Systems are now applying the same technologies to library work in a way that promises to change the whole way staff work and patrons visit the library. This article looks at the benefits of the 3M™ Digital Identification System is bringing to the Curriculum Materials Library (CML) at the University of Nevada, Las Vegas (UNLV).
E‐Commerce — buying books on the Internet
Authors: Gilbert Geoffrey
Published: February 2008

This article explains how and why the University of Birmingham have started using the Internet in the acquisitions process. Some of the practical problems as well as the advantages are discussed. Suggestions are made about what conditions need to be met for more use of the Internet to be made.
Advertising on the network
Authors: Kelly Brian
Published: February 2008

Can Universities advertise on their institutional Web site? What forms can advertising take? What are the dangers associated with advertising? This article addresses these issues.
Going one step further — The British Library joins the ranks of free Internet Service Providers (ISPs)
Authors: Lowery John
Published: February 2008

This paper is about the British Library's free Internet access service, British Library Net, launched in September 1999 as the first ISP by a public sector body. The paper explores the rationale behind the development of the service, the work involved in both its creation and ongoing development and takes a look at future trends in the ISP market. The contents of this article had their genesis in a presentation given by Brian Kefford of the British Library at the Public Sector Online 2000 conference.
Electronic commerce and the Scottish Cultural Resources Access Network
Authors: Royan Bruce
Published: February 2008

The SCRAN multimedia resource base has been built with capital funding from the National Lottery, but its future relies on securing a revenue stream to support its services. This article describes how SCRAN has gone about building an e‐commerce service.
Building up a home based information business, using the internet: a personal view
Authors: Nutting Diana
Published: February 2008

The internet has made it much easier to build up a free‐lance information business working from home, not only using the web for information sources, but also for networking and for finding work. The key to running a successful home‐based business is to offer added value information services to companies that would not otherwise use information professionals.
E‐business —the ultimate information opportunity
Authors: White Martin
Published: February 2008

E‐Commerce is the latest boom in consumer technology. What are the benefits, as well as the drawbacks to this development? How can we use it to our advantage? This paper takes a detailed look at e‐commerce and how it is shaping our future.
E‐commerce resources on the web
Authors: Pedley Paul
Published: February 2008

No matter where you look there seem to be news stories, journal articles, and television and radio programmes about e‐commerce. Indeed, this has now moved on from e‐commerce to e‐business and more recently to m‐commerce. There are a lot of websites covering e‐business /e‐commerce and I have tried to trawl through these sites and pick out some of the best that are available.
Managing Electronic Journals — the Ideal World Versus Reality
Authors: Brock Sally
Published: February 2008

Over the past year South Bank University has seen a huge growth in its access to electronic journals, with the number of titles increasing from around 800 to over 2300, which far exceeds the number of journals held in print format. Other universities are following a similar pattern and as a consequence most are experiencing problems. Fundamentally, the ideal world of electronic journals is very different from reality and this article discusses some of these issues.
Knowledge Management issues in universities
Authors: Ratcliffe‐Martin Valerie , Coakes Elayne , Sugden Gill
Published: February 2008

This paper describes some basic concepts of knowledge management, and explains, using these definitions, why universities are not always seats of learning or knowledge sharing. A knowledge management programme, initiated by a leading British university, is described. The authors conclude by suggesting that knowledge management tools may be beneficial to supporting academics in their multi‐faceted work. However, time will tell as to the extent to which they can actually share tacit knowledge and enable real organisational learning across cultures in universities.
Knowledgeshare: Managing Knowledge in the new NHS
Authors: Fairbrother Peter
Published: February 2008

This article outlines the development of a Brighton‐based NHS knowledge management project called Knowledgeshare. The project is discussed with reference to knowledge management theory and its contribution to the Department of Health's ‘Information for Health’ Strategy.
Knowledge Management within the UK Oil Industry: A case study on Knowledge Management implementation within OILEX Ltd
Authors: Smith Judith M , Duncan Lisa
Published: February 2008

A study was carried out at OILEX from September to November 1999 which examined the extent to which the organisation was capturing and sharing its knowledge and experience. Evidence suggested that OILEX was capturing its experience, but sharing of this experience is limited. There was a need to recognise at top level that transforming “individual experience” into “corporate knowledge” is critical to the long‐term competitiveness of the organisation. This paper outlines approaches to knowledge capture and sharing within OILEX at present, and discusses the recommendations that were made in ways of levering the organisation's competitiveness for the future. External factors such as general trends in the industry, falling recruitment, an ageing workforce and use of contract workers have all made an impact on sustaining knowledge and experience within OILEX. Internal factors such as working culture, the specific demands of project work and the organisational structure are also cited. In a competitive environment, maximising all of the company's assets is crucial. This paper suggests ways in which OILEX can benefit from individual experience through its transformation into group learning, and discusses the implications for the company in adopting a programme of capturing and sharing learning. It goes on to highlight the ways in which more effective Knowledge Management impacts directly on savings in staff time, avoids duplication of work already carried out and allows the whole organisation to learn from previous mistakes. Ultimately, such learning leads to greater efficiency and productivity. Different teams within the organisation are able to draw on the learning of others to respond more quickly to problems. They can then transfer their learning back into the knowledge pool, thereby contributing to a constantly evolving “memory bank” of experience.
Issues of trust in Knowledge Management
Authors: Patrick Keith , Rourke Grahame , Phillips Nigel
Published: February 2008

A common feature of the Knowledge Management (KM) discourse, written or spoken, and regardless of whether it is technologically or people orientated, is the stress on the importance of trust. The importance of trust can be seen in its regular citing as a critical success factor in any knowledge management initiative. This poses a significant question, when we examine the last twenty years of management strategies, they can be seen to undermine trust.
Managing knowledge
Authors: Hornby‐Atkinson Patricia , Hornby Susan
Published: February 2008

Historically the profession of information work has been related to the collections or where they are stored, for example, librarians worked in libraries; today this idea is becoming more complex and is changing and developing. Information work is more about a process, the collection, dissemination and utilisation of information and knowledge.
Information UK 2000:‐ a ten year look ahead
Authors: Martyn John
Published: February 2008

At the end of last year, Bowker‐Saur published Information UK 2000 on behalf of the British Library. This is the report of an attempt to forecast the most significant developments in the way information would be generated, handled, stored and used over the next decade, and to assess their possible impact. A number of experts were invited to express their views as to the likely changes and developments in their areas of expertise which could have an impact on the library and information world. These experts were organised into Task Forces, each considering a specific theme. The experts first prepared individual forecasts, which were combined within each Task Force, by one member acting as coordinator, to provide a consolidated forecast for each theme. The Task Force reports were then combined, together with inputs from other studies, to produce a final report constituting a global forecast covering the whole of the field.
Public information systems: serving the wider community
Authors: Springthorpe Mark
Published: February 2008

Until April 1995, Mark Springthorpe worked for Nottinghamshire County Council and was the Project Manager responsible for the implementation of County Contact, an electronic public information system which represents the largest commitment made by a single UK publicly funded organisation for a customer‐facing, interactive kiosk system. This article describes the experiences gained during this period and examines some of Nottinghamshire's plans for the future. Having spent time at Interactive Software Products Ltd, Mark now works for ITnet where he is the Senior Consultant for Local Government.
Electroless Copper Plating Troubleshooting
Authors: Shemilt H.R.
Published: February 2008

The high cost of copper combined with a world shortage has emphasised the need for economy in its many applications. The manufacture of printed circuits by the etched foil technique produces a wastage of 60–80% of the copper cladding of the boards and although recovery of the copper can be effected, the process is costly and time consuming to an extent that makes it impracticable for the printed circuit manufacturer. With the increasing use of additive processes for printed circuit manufacture and the consequent saving in copper wastage, the use of electroless copper plating has assumed even greater significance than for its application to through hole plating and the advantages gained by freedom from the current density problems associated with electroplating need no stressing.
Thickness Measurement of Gold Deposits
Authors: Reid F.H.
Published: February 2008

In both decorative and industrial applications of gold plating, but even more critically in the latter, accurate measurement of coating thickness is of vital importance to both the manufactuer and the user. To the former, working to increasingly stringent specifications, it may, in extreme cases, mean the difference between profit and loss if an excessive thickness is inadvertently applied due to some change in electrolyte or processing conditions, or if an unduly high average thickness must be used on barrel or vat plated components to ensure a minimum requirement on functional areas. To the user, it can equally mean the difference between operational success and failure of a gold plated part if plating thickness is below specification and the means used for measurement are not sufficiently precise to detect this. Control of coating thickness in gold plating is therefore a matter of vital concern, and never more so than at the present time when, in the face of the spectacular price increases of recent years, and in the virtual absence of viable alternatives to meet the exacting demands of applications in printed circuitry, semiconductor technology and the electronics industry in general, the need for maximum economy in gold usage has become increasingly urgent, as evidenced by the vigorous efforts currently devoted to the development and improvement of selective plating techniques, and the recent interest manifest in the possible replacement of essentially pure gold coatings by alloy deposits of 18 carat and lower where these may be technically acceptable. The present article offers a wide‐ranging survey of methods available for thickness measurement, with particular reference to gold plating, but including also some techniques which, whilst not finding current use, may be of potential interest in this context.
De‐Wetting of Fused Tin/Lead Plated Printed Wiring Boards
Authors: Williams R.
Published: February 2008

The increase in printed wiring boards exhibiting de‐wetting characteristics after the fusing of electroplated tin/lead coatings prompted this investigation. Although it became clear during the course of the investigation that the development of the resist was a contributing factor to de‐wetting, it was shown that the sulphate ion concentration of the final rinse before tin/lead plating was the major cause of de‐wetting.
Photosensitive Resist Printing
Authors: Shemilt H.R.
Published: February 2008

In this series of articles on printed circuit troubleshooting, the author in this issue of the journal focuses his attention on photoresists. The problems that most commonly occur during lamination, film development, subsequent plating processes, coating consistency, resist exposure and development are detailed.
The Philosophy of Quality Control in Soldering Operations
Authors: Thwaites C.J.
Published: February 2008

Quality Control and/or Assurance and similar phrases are in common use but can have different meanings, depending on the type of product involved and on economic considerations. It is proposed that, from the soldering point of view, component design and solderability must be as good as possible and must be regularly checked. There must be adequate control over every aspect of the soldering process, and inspection of the completed assembly must be meaningful with realistic accept/reject levels decided upon at the outset. Having established a complete production scheme incorporating quality checking, it is proposed that no alterations should be made without full consultation and collaboration with all the personnel concerned.
New Photographic Material for Printed Circuits
Authors: Buroff A. , Simidchieva P. , Stoycheva R. , Malinowski J.
Published: February 2008

Recently a number of new photographic systems have been investigated with the object of replacing the conventional silver halide emulsions and as such could possibly represent the basis for further development of new methods of production for printed circuits. By using prepared combinations of metal and a light sensitive substance, e.g., arsenous sulphide/silver and cadmium iodide/tin, one can obtain directly a positive metal image. This approach by the authors was used for the development of a new direct positive photographic material for printed circuits which is easily processed and can be safely stored.
National and International Committees for Printed Wiring
Authors: Shemilt H.R.
Published: February 2008

In this issue of the Journal we conclude our series of articles on National and International Committees for Printed Wiring by examining the work carried out by “Panel Z‐Printed Circuit Techniques and Materials” of the Radio and Electronic Components Manufacturers' Association. In the past five issues of the Journal we have covered, as far as we are aware, all of the committees concerned with printed circuits which are currently functioning. However, we have yet to hear from overseas readers who are associated with, or are members of committees dealing with printed circuits or allied techniques with a view to preparing an article on their behalf for publication in a new series to start sometime next year.
The Uses of Organic Polymers in Electronics Packaging with Particular References to Printed Circuit Modules
Authors: MacLeod Ross W.
Published: February 2008

In this paper a review is given of the more commonly employed organic polymers for coating and embedment of electronic modules. Following discussion of the basic types and their properties, problems arising from emission of volatiles from encapsulants are outlined and the importance of considering these in early design stages is stressed.
Some Facts and Figures on Israel's Printed Circuit Industry
Authors: Fischler J.
Published: February 2008

In this issue of the Journal we continue with our series of articles describing the current situation of the printed circuit industry in various countries throughout the world and as such focus our attention on Israel. This article has been submitted by Mr. J. Fischler of Micronics Ltd., Tel‐Aviv, Israel and his cooperation is gratefully acknowledged.
Whisker Formation on Electronic Materials
Authors: Dunn B.D.
Published: February 2008

The filamentary growths of single crystals on material surfaces are termed whiskers. They are seen to nucleate and grow on certain electronic materials either from vapour and liquid phases or by a process induced by residual stresses in electroplated surfaces. Whisker growth does not depend on the existence of an electric field and surfaces prone to their growth may nucleate and form whiskers as a result of exposure to a space environment. This paper includes a detailed examination of tin whiskers which were found to have 1 to 4 micron diameters and lengths exceeding 2 mm. Some were found to carry currents between 22 and 32 mA before burning out. Conductive whiskers can cause extensive short circuit damage to spacecraft electronics particularly as miniature devices progressively employ closer spacings between conductors. Several modes of whisker growth on spacecraft electronic materials (molybdenum, tungsten, Kovar, tin) have been observed and are described. Tin, cadmium and zinc surfaces can support stress‐induced whisker growth and it is recommended that these metal finishes are excluded from spacecraft design and possibly replaced by a tin‐lead alloy.
Standards for Copper‐Clad Laminates
Authors: MacLeod Ross W.
Published: February 2008

Specification by manufacturer's grade, restricts competition; company specifications proliferate test methods; both increase costs. BS.3888 was incompatible with foreign specifications. IEC Publication 249 promised internationally acceptable standards and led to the flexible approach to BS.4584 which allows for progressive additions to the range of test materials—now at seven—with a further seven in the foreseeable future.
Cost Effective Screen Printing
Authors: Davison J.W.
Published: February 2008

In this paper the types of screen printing inks available for curing by ultra‐violet light are described. A comparison is made with conventional thermally cured inks and the author asserts that the current drive towards energy conservation and reduction in atmospheric pollution has been a powerful stimulus to the development of UV cured inks. The cost effectiveness of these inks is examined by reference to the energy required, operational costs, equipment, the ink itself and reject rates.
A Comparison of Die Perforated Holes with Drilled Holes
Authors: Golonsbe Edmond E.
Published: February 2008

In this paper, reproduced by permission of the Institute of Printed Circuits (USA), the pros and cons of die perforated and drilled holes are discussed in relation to speed of production and quality of plated‐through holes, both with etched and additive printed wiring boards, single‐ and double‐sided.
A Question of Measurement
Authors: Brooks J.S.
Published: February 2008

Is accuracy or reproducibility more appropriate? How sensitive need it be and what will be the loading effect if the instrument is used? Should a recording version be purchased? This paper defines the terms used in instrument specifications and suggests the questions which need to be answered before a rational selection can be made.
The Effect of Drilling Temperature on Multilayer Board Hole Quality
Authors: Weiss R.E.
Published: February 2008

The Quality of holes drilled in multilayer printed circuit boards and the usable life of a drill are a function of the drilling speed and feed rate per revolution. Investigations have shown that, as the RPM is reduced and the feed rate per revolution (bite) increased, both hole quality and drill life are improved. The temperatures generated during the drilling process have been measured as a function of RPM and feed rate, and shown to be the cause of the variation in drill life and hole quality. Experimental data substantiating these results is presented. Acknowledgement is made to the Institute of Printed Circuits for their permission to reproduce this paper.
Drilling Multilayer Glass‐PTFE Circuit Boards
Authors: Hagge John K.
Published: February 2008

In this paper, reproduced by permission of the Institute of Printed Circuits (USA), the author discusses some of the problems encountered when drilling holes which must be plated through in multilayer glass cloth‐PTFE circuit boards and gives recommendations for overcoming them.
Computer‐Generated Cutting Patterns Reduce Shearing Scrap
Authors: Justice Jeff
Published: February 2008

The problem of how to cut small, rectangular panels from larger stock‐sized material with minimum scrap is common in many industries. In 1975, Hewlett‐Packard's Palo Alto printed circuit facility began using a computer‐generated shearing pattern technique that has proved very successful. This paper describes the Company's experience in implementing this system. Acknowledgement is hereby made to the Californian Circuits Association for their permission to reproduce the paper which was originally presented at a recent CCA conference.
Epoxies in Thick Film Hybrid Circuits
Authors: Marshall C.
Published: February 2008

Conductive and non‐conductive epoxies suitable for thick film circuits have been available since about 1970. They were originally intended for mounting semiconductor chips as an alternative to eutectic bonding, but they are now used for a much wider range of applications. This paper discusses the practical problems and results of epoxy mounted semiconductors in the light of five years manufacturing experience, and goes on to look at some of the latest applications for epoxies in thick film hybrids.
Non‐Woven Glass Laminates
Authors: Aggleton M.J.
Published: February 2008

Non‐woven glass epoxy laminates are compared with paper phenolic and woven glass epoxy, indicating the advantages and limitations of the newer materials. Certain electrical properties are compared together with thermal and dimensional stability performances. This paper was presented at the Institute of Metal Finishing Printed Circuit Group Symposium “Circuits 77” in London during March 1977.
Relationship of Corner Cracking in Multilayer Board Holes to Pyrophosphate Copper Plate
Authors: Sherlin D.E. , Bjelland L.K.
Published: February 2008

In this paper, reproduced by permission of the Institute of Printed Circuits (USA), the authors discuss the problem of corner cracking in multilayer boards in relation to the electrodeposition of copper from the pyrophosphate electrolyte.
Design Considerations for Flush Circuits
Authors: Wheeler James
Published: February 2008

A flush circuit is one in which the surface of the conductor is within a minute fraction of an inch from the surface of the substrate itself. Flush circuits are produced by adding epoxy to the surface of a previously etched PCB by one of two primary methods. This article discusses the flushing process, its basic applications, and the ways to design flush PCB's for high reliability and low cost.
Computer Aided Design of Printed Circuit Boards
Authors: Myers Robert L.
Published: February 2008

The initial motivation for photoplotting artwork was increasing accuracy requirements. Photoplotting requires translating a design to digital form before creating the artwork. Present CAD and interactive graphics systems are making increased use of this data base to generate a larger percentage of the documentation required to manufacture a PC board. Computer aided manufacturing such as numerically controlled drilling and component insertion is another feature of today's CAD systems. Future systems will not only increase the merger of CAD/CAM, but also address the ordering of components, cost analysis and many other associated functions in the design and manufacturing of PCB's. Every company producing PCB's should be able to evaluate interactive graphics and determine if and when CAD would be cost‐effective.
Printed Wiring Board Cleanliness Testing
Authors: Tautscher Carl J.
Published: February 2008

This paper discusses the MIL‐P‐28809 Cleanliness Standard and Test, the reasons for testing, how to test, how much it will cost and what the benefits and limitations are.
A Review of Accelerated Ageing (Environmental Testing) of Printed Boards with Respect to Solderability
Authors: Wilson G.C.
Published: February 2008

An electronic assembly may consist of a printed circuit and various types of electrical components. Soldering to make the electrical/mechanical connection is a critical process. Both printed circuit and component leads must promote acceptable solder wetting if high reliability is to be obtained. Bulk purchasing of these items can lead to long periods of storage often in poor conditions. This paper describes some of the work which simulates storage conditions by accelerated ageing so that a prediction can be made as to whether solderability will be affected. Due acknowledgement is hereby made to the EIPC for their permission to publish this paper which was presented at a recent EIPC seminar.
United Kingdom National Specifications and Standards for Printed Circuits
Authors: MacLeod Ross W.
Published: February 2008

BS 9760 and three sectional specifications for rigid printed circuit boards have now been published. The Institute's representative on BSI Technical Committee ECL/19 outlines the new standard system and shows that it offers a good opportunity of achieving international status. The future of BS 4025, the best known British Standard for printed circuit boards, BS 4597 and the interim Defence Standards is limited. The author appeals to Institute members to support ECL/19 in its work of ensuring that the printed circuit producer and user have meaningful and cost‐effective standards.
Filtration and Purification of Solutions Used in PCB Manufacture
Authors: Berg J.H.
Published: February 2008

Electrolytic and electroless plating solutions as well as photo resists, etc. all require solids or organic impurity removal, not only to attain, but to maintain high quality PCB production. Consequently, the need for greater cleanliness has brought about rapid advancements in the field of filtration and purification of plating solutions. This paper describes current approaches to these problems.
Drilling Fundamentals
Authors: Arnold A.W. , Friedli P.W.
Published: February 2008

Drilling and routing are the only two conventional mechanical machining techniques used in the production of printed circuit boards. Unfortunately these operations are still often underestimated even though drilling, in particular, is just as important as the other processes involved in achieving the final quality of the finished board. The advantages and disadvantages of the various drilling techniques are discussed. This paper was originally presented at the First Printed Circuit World Convention held at the Cafe Royal, London in June, 1978.
Flexi‐Rigid Boards—A Total Interconnect System
Authors: Scarlett J.A.
Published: February 2008

The development of polyimide based multilayer flexi‐rigid boards has opened up new horizons in packaging and interconnections. It is now possible to design small electronic systems in which every component can be mass‐soldered to a single interconnect and component mounting unit. Large boards can be made to fold up to fit into small cases, and boards can be designed to fit into awkward shaped spaces such as round the neck of a crt in a video display unit.
Printed Wiring Design Aspects of Using Permanent Photopolymer (Dry Film Solder Mask) Coatings
Authors: Hickman J.J.
Published: February 2008

The advantages of incorporating permanent photopolymer (dry film solder mask) coatings into high density printed wiring designs to obtain maximum component density and high reliability are discussed. Although originally developed for use as solder masks, these materials offer significant advantages to the PCB designer. Specific items to be discussed include high density conductor routing, in accordance with the proposed MIL STD 275D, on the solder side and under closely spaced components, component and heat sink mounting, the use of permanent polymer coatings to avoid metallic growth problems, new industry and military specifications and standards that relate to the incorporation of photopolymer masks into PCB designs and effects of coatings on high density, controlled impedance transmission lines.
New Generation of Electronic Components and How They Influence Printed Circuit Boards
Authors: Weinerth D.
Published: February 2008

The approach to reduce the costs of electronic circuits will be the transition of LSI‐circuits to VLSI‐circuits, introducing another order of magnitude to the complexity and density of these circuits. The influence of this will be similar to the transition of discrete transistors to integrated circuits. VLSI‐circuits are, in general, digital circuits and therefore the passive components used in analogue circuits will be used in smaller quantities, just as the discrete transistors will change from small signal to power. Sensors and display units as liquid crystals will gain importance and need to be interconnected in an economic way. Competing with printed circuit boards are hybrid circuits, but these have not yet found general application due to the high innovation rate of integrated circuits. However, special applications as high frequency circuits are cost effective. A cost breakdown of electronic equipment shows that due to the introduction of LSI and VLSI circuits the relative costs of PCB's are rather high and that economics will force the introduction of new technolgies to achieve the correct cost balance.
Advances in Printed Circuit Drilling
Authors: Icough Martin
Published: February 2008

NC drilling and routing have come of age and have revolutionised the process of drilling holes in PCBs. Computer controlled (CNC) machines are being introduced and the microprocessor will speed this process. This paper demonstrates the improvements to be made in hole quality and machine usage employing machines originating in Europe rather than in the USA as was previously the case.
Quality Assessment
Authors: Bulwith Ronald A.
Published: February 2008

In striving to produce higher yields and fault‐free printed wiring assemblies, the PWB processor usually finds solder shorting or bridging to be one of the most difficult faults to eliminate. Finding himself faced with a high incidence of solder bridging, he usually attacks the problem by examining his own process parameters. Fluxing, preheating, solder composition and temperature, conveyor speeds, etc., are all assessed and adjusted so that the problem is minimised as much as possible. But still it appears, though at a lower level of incidence (l‐3%). With nothing else in his arsenal of weapons to attack this persistent problem, the process engineer is left somewhat helpless, wondering what further he can do to aid his course.
Optimum Design of Flexible Printed Circuit Boards with Respect to Flexural Strength
Authors: Nitsch H. , Ackermann D.
Published: February 2008

In the course of flexible PCB manufacture where the reliability of those parts subjected to bending stresses is a matter of utmost concern, the design of the PCB should enable the flexible interconnection parts to withstand the greatest possible bending stresses. Therefore, extensive investigations were carried out to demonstrate the relationship between the design and flexural strength. The study shows the functional correlation between bending radius, material thickness, type of material, design of the circuit and number of bending cycles. Only with a detailed knowledge of these five mentioned properties can reliable PCBs be designed and manufactured. The results of these investigations are based on a great number of bending experiments performed on a practical basis and demonstrate the numerical relation between all effects. As bending cycle results are subject to relatively high deviations, the whole problem has been investigated by means of statistical evaluation criteria.
BS 9000 and Printed Circuits
Authors: Reynoldson T.
Published: February 2008

The BS 9760 series of specifications, covering rigid and flexible printed circuits, is described. The objectives and structure of the BS 9000 specification system are also described, with particular emphasis on the Capability Approval procedure invoked by BS 9760 (1977). BS 9760 requires the use of standard test patterns wherever possible, thus ensuring a consistent assessment of each approved manufacturer. Recently agreed additions to the current documents include a revised thermal shock test for plated through‐holes, a test pattern and tests for solder‐resist and marking inks, and a procedure for assessing re‐work. Draft harmonised CECC specifications have a very strong relationship with BS 9760.
The Business of Printed Circuits
Authors: Josephs R.
Published: February 2008

Making and selling printed circuits is a high technology business today. It needs skilled management for growth in success and profitability, and the factors to be considered are myriad. Some of them related to marketing, technology, and business, including the advent of the microprocessor, are considered. General trends are reviewed briefly and the requirement pressure to approach the ideal interconnection capability is examined. Then time sharing using the bus‐structure is suggested to continue the personal view of the possible way ahead in the Industry for the decade just starting.
Evaluation of Drilled Hole Quality as a Function of Speed and Feed in Multilayer Boards
Authors: Weiss R.E.
Published: February 2008

Studies of the drilling process have shown that a direct correlation exists between the quality of a drilled hole and the energy expended by the drilling system in forming the hole. As the drilling energy increases (for a given board and drill) the quality of the hole decreases. Hence drilling energy can be used as a measure of drilled hole quality. A drilling energy monitor which can evaluate drilled hole quality on line is being used to investigate several aspects of the drilling process. One of these studies, the effect of feed‐rate and spindle speed on drill performance is the subject of this paper. Drilling energy as a function of drill age has been investigated at several combinations of feed‐rate and spindle speed. No. 56 drills were aged in 8 layer multilayer boards for up to 3000 holes while monitoring the drilling energy. Spindle speed was varied between 60 and 300 inches per minute. It was found that the rate of increase of drilling energy is lower for drills worn at a high advance per revolution than for drills worn at a low advance per revolution. Longer drill life can be obtained by drilling at a high advance per revolution. Spindle speed had little effect on the rate of increase of drill energy over the range of feed and speed used in this study. This paper presents the experimental data and makes recommendations on the proper usage of No. 56 drills.
Measuring the Thickness of Coatings on Printed Wiring Boards
Authors: Latter T.D.T.
Published: February 2008

The Beta Backscatter Coating Thickness Gauge has been a very well used “tool” in printed wiring production for many years. The increased requirement to more closely control the quality and cost of high priced materials and processes has been met by instrument developments utilising microprocessors, not only for measurement but also for instrument, operator and results evaluation. Despite this, the instrumentation will only deliver the correct results if given correct information in the first place, thus, the operator must know a little of the preceeding coating process or at least be given the relevant and correct information. This paper describes the importance of the substrate material and the density of the coating material when measuring coating thickness.
The Use of the Laser for the Inspection of Printed Circuit Boards and Laminates
Authors: Bedford J.
Published: February 2008

Scanned Helium‐Neon laser beams are finding increasing use for non‐contact industrial inspection applications where high resolution detection of optical properties of materials and components is required.
Using Hydrogen Peroxide/Sulphuric Acid Spray Circuit Etchant
Authors: Kear Fred W.
Published: February 2008

Among the many types of printed circuit board etchant now available, there are a variety of notable advantages and disadvantages. This is confusing to the PCB manufacturer because all of these etchants work relatively well. In order to assess the advantages of a given etchant properly, the circuit engineer must consider all aspects of its use including its effect on plant effluents and the difficulty of recovering etched copper from solution. Peroxide/sulphuric etchant offers distinct advantages in these areas of peripheral cost, as discussed in detail in this paper.
Screen Printing for Printed Circuit Boards
Authors: Walter C.A.
Published: February 2008

Silk screen printing is a much used method of producing the required images on printed circuit boards. This paper discusses in detail the techniques and limitations of the process.
KNOW THE DRILL
Authors: Cox David
Published: February 2008

An appreciation of the material from which modern printed circuit board drills are fabricated and an understanding of the salient geometric design features incorporated in such tooling will help those involved with the drilling process in determining optimum operating procedures and in identifying the underlying causes of hole deficiencies.
Costing a Printed Circuit Board
Authors: O'Hara Brian
Published: February 2008

This paper outlines a practical method of working out the true cost of producing PCBs which, with the addition of profit margins, will give the selling price. Following a brief reference to various ‘rule of thumb’ methods, the paper will examine the labour, material and overhead cost associated with each particular process operation, the planning of a suitable costing and will cover all the important parmeters with the accent on simplicity. Performance levels are assessed together with the question of quality.
Effluent Treatment and Water Conservation in the Printed Circuit Industry
Authors: Hutt M.J.
Published: February 2008

The pretreatment, electroplating and etching processes used by the PCB industry are unique in comparison with the plating industry generally. This paper deals with the treatment of the various sources of effluent, bearing in mind the stringent and strictly controlled quality standards. This paper also examines the various sources of effluent and the problems they present. The extent to which high purity water is required is discussed, as are the considerations to be made with regard to water recirculation and conservation in general.
Mass Lamination as a Laminator's Service to the PCB Industry
Authors: Baillie R.J.
Published: February 2008

This paper describes the principles of mass lamination as applied to the production of multilayer printed wiring boards. Recent development of the service is briefly discussed, highlighting the ways it can reduce costs and investment required to produce in large volume. A description of the process follows, providing an indication of the scope and nature of inner layer preparation, up to the final bonding stage. Reference is also made to the method used of location for drilling and finishing operations.
Coating Thickness Measurement—and what to do with the Results
Authors: Latter T.D.T.
Published: February 2008

Modern industry and domestic users continue to demand increasing quantities of coated products. Since price, performance and appearance are all dependent upon the thickness of these coatings, it is mandatory to measure thicknesses as fast, as accurately and as economically as possible. Modern technology has largely solved the mechanics, or more correctly the electronics, of the actual measuring process, but now most ordinary users find problems in how best to use the results for the greatest overall benefit. The Beta Backscatter method of measurement applied to the production and use of printed circuits is taken as an example of what can be done with a little more knowledge, perhaps a little beyond that of simple coating thickness measurement.
Technology of Manufacture or Technology of Application—Which Will Change More?
Authors: Nicholson E.H.
Published: February 2008

Semiconductors and PCBs have progressively become the leading two components in the electronics industry, although marked differences exist between them. PCB technology has witnessed considerable changes in the past 20 years with the progression from simple print and etch to double‐sided PTH and then to multilayers. Analogies are drawn with other industries where plateaux are reached beyond which the pursuance of certain developmental trends would be impractical. Just as there is a limit to the number of layers of practical benefit in multilayers, so too there is a minimum space between conductors, any reduction in which will lead to decreased reliability. The wide variety of processes in a PCB company involve a vast range of types of employee, although there is frequently a transfer from one function to another and a considerable degree of “vertical integration”. “Horizontal” integration is envisaged for the future to hold costs to a minimum.
Substrates for Surface Mounted Components
Authors: Messner George , Lassen Charles
Published: February 2008

A dramatic growth‐rate is envisaged in the next decade in the demands on the integrated circuit industry, posing the question of the necessity for new techniques. Present technology does not lend itself to continued linear extension, and new semiconductor package types of increasing complexity require purpose designed interconnection systems. Tape Automated Bonding and Leadless Chip Carriers are currently becoming fairly widely used alternatives, while emphasis is being placed on developing the surface attachment concept. Potential problem areas centre around the cost of interconnections, which is closely dependent on their density; the heat dissipation properties of substrates encountering considerable heat generation from complex circuits; flexibility of design, and faster design time and delivery requirements. However, printed circuit technology is assured a healthy future provided that adjustments are made and experiments undertaken, such as those involving thick film hybrid technology, the use of porcelainised steel substrates, and the Lampac, Pactel and Microwire techniques for high density interconnection systems supported on metal planes.
High Density Metal Core Printed Circuit Boards
Authors: Morisaki G. , Sato T. , Kikuchi H.
Published: February 2008

To solve the problems associated with heat generation as packaging density increases, especially with the use of VSLI devices, high density metal core PCBs have been developed. The manufacturing process is evaluated alongside that of conventional G‐10 boards, as are the electrical properties of the two types. Characteristic impedance and propagation delay figures are compared; back crosstalk and heat dissipation capability are investigated, the incorporation of the metal core being found to produce a considerable improvement in terms of heat conductivity.
Polysulphone Circuitry for High Frequency Applications
Authors: Neagle Peter J. , Newton Thomas D.
Published: February 2008

In attempts to meet the need for low‐loss materials capable of attaining the dielectric properties that are required for rapidly developing microwave and high speed digital equipment, polysulphone in its various forms has been undergoing investigation. Microwave dielectric properties are examined with respect to temperature and frequency, and three types of polysulphone are studied in depth, with testing for dielectric constant and dissipation factor. The material's physical properties are listed prior to advisory comments on special processing requirements. Its feasibility in multilayer production is currently being researched.
Etching Parameters: Their Individual and Collective Impact on High Density Circuit Production
Authors: Swartzell James C.
Published: February 2008

High density PCB production requires ever closer investigation of the factors which influence the ability to fabricate efficient circuitry. One of these, etching, is examined, revealing that even that process alone is subject to the effect of physical, chemical and hydraulic parameters. Physical factors include raw materials, circuit geometry and process equipment, etcher spray systems being discussed at length. The implications of the chemical parameters are specifically linked with etchant formulation. Oxidation reduction potential and etchant density effects are also dealt with before the final section on hydraulic factors, where the importance of the design of the hydraulics system is underlined.
The Printed Circuit Challenges of the '80s
Authors: Mettler R.
Published: February 2008

The printed circuit has been a fundamental building block for the electronic industry for several decades. What will be the impact on our industry of technological developments, design demands and functional requirements in the next few years? Chip carriers—0·010 in. holes—0·001 in. lines and spaces—surface mounting of components—organic circuits—programmable circuits—microminiaturisation—new substrates—new metallisation—building to electrical rather than physical specification. Assuming continued explosive electronic growth, coupled with accelerated evolutionary developments, will the present structure, philosophy and management of our industry permit it to respond effectively to these challenges.
Thermal Implications of Using Chip Carriers with Current Laminates
Authors: Gregory P.
Published: February 2008

The evolution of epoxy glass fibre PCBs generally accepted by the industry has not produced major developments in laminate technology. Microminiaturisation of components, improved packaging of ICs by chip carriers has made apparent that current laminates will be unable to meet interconnection needs and thermal dissipations. This paper discusses the thermal characteristics of alternative systems using metal cored boards and ceramic substrates.
ICT News
Authors: Walker J.B.
Published: February 2008

On Wednesday 13th October, 1982, the Cahners Exposition Group, proprietors of the Internepcon Exhibition, sponsored and organised a special banquet to honour two individuals who had made major contributions to their respective Industries.
Broader Functions and Improved Reliability of Printed Circuit Boards Using Dry Film Solder Mask Systems
Authors: Weinhold M.
Published: February 2008

This paper deals with the design of PCBs, using the dielectric properties of solder mask as an insulation layer to protect boards and components; the elimination of selective solder filling of component holes; the protection of via holes during soldering, and the preparation of artwork, with particular attention to design tolerances using dry film solder mask. Future prospects in PCB design, employing dry film solder mask, are also discussed.
Heat Plates, Ladders and Sinks by Photochemical Milling
Authors: Cane P.L.
Published: February 2008

The production of these passive components by Chemical Milling is becoming more common. The author discusses artwork generation, etch allowances, phototooling, types of materials, identification number and logo markings on and in the surface, the pros and cons of step etching and prepreg cutters, and concludes by considering normal tolerance inspection requirements and packing.