Book Reviews

First thing that strikes you is that the title is not ideal; the publishers should have picked this up. Lead-free should have been in the main title as sales would have been higher when the book hit the streets but this is in no way a criticism of the content.

Kluwer have a number of other titles that engineers in our business should check out. I for one was not aware of the Area Array handbook written by two IBM engineers or the new title by John Blade on Multi Chip Modules. The publisher's website should be scanned in detail for useful titles.

The book is divided up into 17 chapters with 400 pages well illustrated with diagrams and photographs. The chapters tend to cover three main topics - materials, components and assembly and finally what is referred to as the "Designers Perspective", material which can be used to understand and predict product life expectancy.

Chapter 1 sets the scene in terms of manufacturing process and the evolution of the different types of printed board assembly. It then leads into the reasons behind the change from the well known and well understood tin/lead solders into the new age of lead-free soldering. Chapters 2 & 3 focus on material properties and the way they react under different mechanical strain. This leads into the next section which relates directly to micro solder joints and how mechanical testing can be used to understand and predict the properties of the joints. There is an interesting diagram from Instron on the different methods of testing microelectronics, it is not until you see them altogether that you realise the breadth of the subject.

The following two chapters examine the testing of bulk solder and actual solder joints providing a comparison of the information that can be gained. These pages highlight the difficultly of taking data for bulk materials and relating it directly with micro joints. Solder joint sections are provided to illustrate the changes in structure that can occur using different testing, this is one area where there could have been far more micro structure images to help the reader understand the metallurgy issues.

Chapters 7, 8 & 9 take the reader through component manufacture, assembly and then failure analysis. Understanding the construction of parts make the failure types easier to understand. Understanding the construction of components also helps to show why poor assembly control can lead to intermittent or complete failure. These chapters are again well illustrated; in the case of components one of the authors has used drawings, photographs and also X-ray images to show part construction. Having seen Angus Westwater present in the past he uses this technique of multiple views to good effect. The failure analysis section illustrates the most common problems associated with the assembly process and is again well illustrated. The techniques used to examine parts and examples of actual failures are provided for the reader to reference.

Finally the last section looks at the methods and methodology of prediction and the different ways in which data can be presented and interpreted. The key issue is that it all depends on the quality of the data. The Open University have been working in the area of lead-free material characterisation for the last few years and have considerable data which allows them and other partners to work with predictive tools.

The book is a very useful and informative read and well worth the investment. The authors will be presenting a workshop on lead free reliability with the SMART Group in March and will provide an ideal opportunity to have a copy of the book signed by the authors, after purchase of course.

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