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A new treatment method for the copper innerlayers of polyimide multilayer printed wiring boards has been developed. Conventional oxide coatings experience acid penetration through the bonding interface during through‐hole plating pretreatment. This problem was eliminated by substitution of metallic copper for the surface oxide. Promotion of the copper innerlayer adhesion to the prepreg by the oxide coating was based upon a mechanical interlocking effect caused by the minute roughness of the oxide crystals. Reduction treatment of the surface oxide layer was found to give a metallic copper surface with no changes in its morphology. Adhesion strength of polyimide prepregs to copper foils after the reduction treatment was equivalent to that of the original brown oxide coating. Acid resistance was enhanced by elimination of the oxide layer from the bonding interface. The reduction treatment, combined with the conventional oxide coating technique, can realise high density multilayer printed wiring boards with greater reliability and performance.

Benchmark problem 10 of the TEAM workshop consists of steel plates around a coil (non‐linear transient eddy current problem). Six computer codes are applied, and 6 solutions are compared with each other and experimental results for eddy current densities as well as flux densities. Some codes were found to give oscillatory solutions.

In the preceding three parts of this series, the authors have extensively reviewed and quantified the special processing sequences required for the ‘additive’ and ‘semi‐additive’ process strategies of PWB manufacture. In this, the fourth part of the series of five, they wish to present a series of full build processes which meet all the interconnect requirements of the 1990s while eliminating the drawbacks traditionally associated with additive processes.

This, the third in a series of papers, reports an investigation of the semi‐additive process strategies of PWB manufacture. It will show that, although the adoption of a ‘naked’ palladium catalyst is the optimal production strategy in terms of cost, caution must be exercised in its implementation, particularly with regard to material process flow and solder mask type employed. It will be demonstrated that the use of a thin, sacrificial ‘flash’ of electroless copper prior to circuitisation and full build deposition will be required for the liquid photoimageable soldermask (LPISM) approach.

Driven by the demand for higher density in electronic packaging, each signal plane of printed wiring board must accommodate more conductors. As a result, conductor width is becoming narrower each year. This chapter reviews some of the important steps of forming finer line conductors in printed wiring boards, such as surface preparation, plating/etching, photo‐exposure, automatic optical inspection, etc.

Although additive manufacturing (AM; 3D printing/3DP) is presently in its infancy, once it becomes economically viable for mass production, it would revolutionize the operation and supply chain network of traditional businesses and manufacturing industries. To this end, approaches for ensuring a smooth transition of the economy, businesses, manufacturing centers and related services are being investigated. This review paper assesses the existing literature on the impact of AM on the maritime transportation sector.

This paper provides a systematic literature review through three methodological phases: (1) a comprehensive review of the number of English language literature studies published on the topics of AM or 3DP (1970–2021); (2) a bibliometric analysis of selected keyword combinations and (3) a detailed review on the impact of AM on different sectors.

The key findings are that existing studies do not attempt to forecast shipping volume and ton-miles that can be affected by the mainstreaming of the technology. Additionally, existing literature that focuses on the impact of the technology on different shipping categories is limited to studies on container ships.

The review identifies some potential areas of research that since maritime transportation will be affected by mainstreaming AM, it will have economic, social and environmental impacts on global trade that require future assessment.

As printed wiring boards move to thin laminate structures, there is growing interest in the use of photoimageable coatings to serve as dielectric. Shipley has developed a liquid photoimageable dielectric which combines liquid coating, imaging and plateability. This paper presents work using this material to produce electrolessly plated lines and blind vias, along with initial adhesion data. Some of the interesting properties of this material are: low dielectric constant, low moisture absorption and good compliance to stress. The material can be processed to provide a high Tg and high plated adhesion can be obtained using conventional swell and etch techniques. It can be imaged and processed using conventional printed circuit coating and imaging techniques. This material will offer a relatively low cost alternative to thin clad laminates and may find use for adding one or two layers to a conventional multilayer board or in providing surface topography for surface mount devices. The paper describes recent developments related to this dielectric and its use.

The uniformity of electrodeposition is the key to successful application of pattern plating because the quality of electrodeposited copper layer has a huge impact on the performance of printed circuit boards (PCBs). The multi-physics coupling technology was used to accurately analyze and forecast the characteristics of electrochemical system. Further, an optimized plating bath was used to achieve a uniform electrodeposition.

A multi-physics coupling numerical simulation based on the finite element method was used to optimize electrodeposition conditions in pattern plating process. The influences of geometric and electrochemical factors on uniformity of current distribution and electrodeposited layer thickness were discussed by multi-physics coupling.

The model results showed that the distance between cathode and anode and the insulating shield had a great impact on uniformity of electrodeposition. By numerical simulation, it had been proved that using an auxiliary cathode was an effective and simple way to improve uniformity of electrodeposition due to redistributing of the current. This helped to achieve more uniform surface of the copper patterns by preventing the edge effect and the roughness of the copper layer was reduced to 1 per cent in the secondary current distribution model.

The research is still in progress with the development of high-performance computers.

A multi-physics coupling platform is an excellent tool for quickly and cheaply studying the process behaviors under a variety of operating conditions.

The numerical simulation method has laid the foundation for the design and improvement of the plating bath.

By multi-physics coupling technology, we built a bridge between theoretical and experimental study for control of uniformity of pattern plating in PCB manufacturing. This method can help optimize the design of plating bath and uniformity of pattern plating in PCB manufacturing.

This paper, the first part of which was published in our September/October issue, was one of eleven read during the 1979 Conference on Operational Aspects of Propulsion Shafting Systems, organized jointly by the Institute of Marine Engineers and the Committee on International Co‐operation on Marine Engineering Systems (ICMES). We are grateful to the Institute for permission to republish the paper for the interest of all who have been concerned with vibrational, flexing and bearing problems inseparable from the development of VLCC and ULCC vessels during the past twenty years.

DESIGN stage investigation of marine shaft systems usually comprises the evaluation of the following elements.