There are two things which are rather surprising about this book: the fact that it is available free of charge (presumably to UK printed circuit manufacturers) and its artistic presentation. Let me state, from the start, that this book addresses only PCB lab and not assembly. It serves a useful purpose, in that the other book which treats the subject, Toxic Waste Minimization in the Printed Circuit Board Industry, already 12 years old, is decidedly out of date. On the other hand, I feel that the older book is probably more comprehensive in its treatment. This volume concentrates more on waste water – and in particular, heavy metals in it – than any of the other sources of pollution within our industry. It is divided into 20 chapters and it is clear that each one cannot give a very comprehensive run‐down on its subject in just a few, well illustrated, pages.
It may not come as a surprise that the printed circuit board industry is, according to a US source, in the top 20 of the industrial water polluting league. How this has been determined is not clear but it does show that books like this are necessary. It probably shows also that there is much ignorance within the industry, particularly amongst the smaller manufacturers who do not necessarily have the expertise needed to handle the subject comprehensively. As is correctly stated in the introduction, “the printed circuit board industry is a particularly good example of an industry sector that has a significant cost burden associated with environmental compliance”. It goes on to state that it is estimated that conformity costs are some three to four times higher than the average for industry as a whole.
The first chapter reviews, within a few pages, the approach and methodology of looking at the manufacturing process and summarises the areas of concern. The second chapter introduces what is the essential part of this book, the problems of copper. There are two useful tables in it, the first showing the highest sources of copper in effluent rinse waters during standard operating conditions and the second one tabulating the treatment of spent chemistry. For those unaware of it, the following chapter describes the methods available for determining the copper concentration in effluent streams. This includes an indication of the concentration range and cost of each one of 12 different tests.
Having determined that copper is in the effluent waste stream, the following chapter shows the options of how to treat it to remain in compliance with the discharge regulations. It should be mentioned that some of the methods may not be applicable in every country. One of the thorniest problems is how to treat EDTA complexes and a chapter is devoted to this subject. Another one discusses the particular problems of electroless copper. It is obvious that chemical cleaning of copper will dissolve some of the metal during the microetch process. What is possibly less commonly realised is the quantity of particulate copper removed during brushing or pumice cleaning and this also is a source of pollution.
One of the longer chapters is devoted to the desmear process. This treats uniquely the permanganate process. The chapter on solid wastes handles both notifiable and non‐notifiable types. Hydroxide precipitation is recommended, within the UK, to be filtered to a 32 per cent solids content, but in other places it may be necessary to have a higher solids content. There are three types of process used for direct plating, the subject of one chapter, followed by the very thorny tin‐lead stripping and plating processes. The chapter on alternative solderable finishes is really only a catalogue, without a detailed environmental study of each one.
Air pollution is covered in a short chapter, entitled “Volatile organic compounds”. In fact, this is probably the weakest chapter in the book. Even the definition of a VOC does not correspond with that in current European directives. The following chapters cover the process plant and process control respectively.
There is an important chapter on the subject of water recycling, which is in the interest of all PCB manufacturing plants. It is estimated that 80 to 90 per cent of rinse waters can be recycled, although, from experience, I would consider this slightly optimistic. A cited case suggests that a small PCB manufacturer may be able to save 850,000 gallons of water per year by recycling.
The chapter on packaging surprised me with the mention of the UK legislation which seems remarkably bureaucratic. Much of the chapter is devoted to the problem of plastic containers. This is followed by the chapter on environmental management systems such as are required for the ISO 14000 series of standards. It gives an important model environmental policy for PCB fabricators. The final chapter discusses an environmental legislation database which is in the course of preparation and intends to list all legislation relating to environmental issues which have an impact on the PCB industry. It will be interesting to be able to review this database at a later date.
The book is completed by a glossary of terms, rather few in number for those who already know very little about the subject.
The presentation of the work is clear, easy‐to‐read and well set out. Some of the photographs are veritable works of art, while others are designed to shock. The drawings are colourful, attractive and explicit. The typography is excellent, with a single exception, the typical UK misuse of units and symbols and their nomenclature. ISO 35 standards should be required reading of all authors, editors and typesetters of technical documents before putting finger to keyboard or pencil to paper. For example, 1 ppm (written here incorrectly as 1ppm) is defined as 1 mg per litre (written incorrectly as 1mg): archi‐wrong!, it is 1 mg.kg–1 and a millisiemens is written milliSiemens in the book and the angstrom is written as the name Angstrom. The ISO document (summarised also in ISO 2000) is extremely clear about how to write units, their abbreviations and their typography: this is not just being pedantic, there are very good reasons for it. For example, is 241m 24 lumens or 241 metres (the risk of confusion may vary with the typeface)?
I am certain that this book will provide a background knowledge for everyone within the printed circuit industry. It is not complete because there are many products which are capable of causing pollution (starting with the laminate itself) and are not discussed. In particular, the question of storage of chemicals is not addressed, even though it is frequently a high risk area in every plant using them. Air pollution is summarily discussed and earth pollution only in relation to landfills, and not in relation to the plant itself. However, the printed circuit does not stop at the gates of the fabricators’ plant, but is also chemically treated at the assemblers’ plant. It would be useful if future editions of this book covered the overall “cradle‐to‐grave” aspects of the printed circuit to include these points, the chemistry of the laminate and, above all, recycling, which – other than water – is hardly mentioned. A chapter summarising the main relevant legislative limits for pollutants in water, air and earth would also be helpful, as would one on prevention of pollution (is there a manufacturer who has not experienced at least one burst drum through an accident with a fork lift?). Notwithstanding these negative points, this book must be placed on the bookshelf of every responsible employee within the industry – and, above all, that of their executive bosses!
