Search results

The new process was developed to offer a superior method of forming a resist pattern on a copper‐clad laminate acting as plating and etch resist. The advantages over existing methods include superior resolution, increased automation, improved reliability, and lower applied cost. The process is unique, combining the precise coating of the blank board with UV coating resist, exposing the resist through a phototool held precisely off‐contact and the development of the formed latent image with an aqueous solution. The processing is carried out using fully automated equipment without any manual handling of either laminates or phototool.

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 ever‐increasing miniaturization and integration of additional functions in the electronics industry – in particular in the next generation telecomm technologies – needs a paradigm shift in manufacturing technologies in order to achieve the results along the roadmaps of the industry. Handling of thin substrates, doing finest line circuitry, working on non‐flat surfaces and having to protect metallized holes during etching processes, are asking for conformal resist coatings. Electrophoretically deposited positive working photo resists encompass these requirements. The principles of electrophoretic photo resists, the necessary equipment, the cooperation between customer, the supplier of process chemistry and the supplier of the equipment to start such a complex project, and start‐up results of the new major production line for ED‐resist in Europe are discussed.

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.

For those fortunate enough to have the opportunity to indulge in a pre‐exhibition stroll in Munich or its environs during the days prior to and at the start of this year's Productronica, the English Gardens provided an ideal setting with varied autumn hues resplendent against a clear blue sky. Even those less fortunate can fail to have appreciated the golden tints of the trees in the exhibition grounds as they bustled briskly between halls.

Cologne, ranking as the largest city in the Rhineland and the fourth largest in Germany, derived its name from the Latin name Colonia—colony. After marching into southeast France, which they called the ‘province’ (retained to this day as ‘Provence’), the Romans headed north towards the Rhine which proved to be the line which halted the Roman conquest. Fierce tribes on the eastern bank were too difficult to subjugate, hence Cologne became the location where Roman administration stopped.

The relentless demand for enhanced electronics processing capabilities is causing major changes in all sectors of the electronics industry, particularly in interconnection and packaging. Printed circuit board line widths and hole diameters are decreasing and new substrate materials are finding increasing use. In addition, newer high density interconnection and packaging techniques such as multi‐chip modules, chip on board and TAB are beginning to move into production. These developments are placing new demands upon PCB manufacturers, who are in turn driving their process suppliers to provide the enabling chemistries. These demands have, for example, encouraged the development of high resolution electrophoretically deposited photoresists, photoimageable solder masks and the chemical deposition of solder from solution. However, against this requirement for improved and new processing chemistries there are growing environmental pressures which have necessitated changes in both materials and processing methods, a typical example being the growing interest in direct plating of via holes. This paper reviews the challenges and opportunities in advanced PCB fabrication from a processing chemical supply perspective and discusses the new processes and chemistries that will enable the PCB industry to produce state‐of‐the‐art boards in an environmentally acceptable manner.

First, a short history of surface mount technology is given, followed by a section describing the current status of surface mount components and the impact of these on printed wiring boards. Then, two essential steps of SMT, component mounting and soldering, as practised in Japan, are discussed. The advantage of additive technology for SMT is briefly reviewed.

An intensive 2½ day short course on Printed Circuit Design will be held at the Sheraton Hotel, Copenhagen, on September 3–5th and repeated at the Lendi Hotel, Brussels on October 1–3rd, Holiday Inn, Birmingham on October 29–31st and the Holiday Inn, Rome on November 26–28th.