An Engineer's Handbook of Encapsulation and Underfill Technology

Soldering & Surface Mount Technology

ISSN: 0954-0911

Article publication date: 1 April 2000




Ellis, B. (2000), "An Engineer's Handbook of Encapsulation and Underfill Technology", Soldering & Surface Mount Technology, Vol. 12 No. 1.



Emerald Group Publishing Limited

Copyright © 2000, MCB UP Limited

An Engineer's Handbook of Encapsulation and Underfill Technology

An Engineer's Handbook of Encapsulation and Underfill Technology

Martin BartholomewElectrochemical Publications Limited, IOMPages 162 + xiiISBN 0 901 150 38 XPrice US$130URL:

Keywords: Publication, Encapsulation, Underfill

This book is well-named, because it is not essentially a scientific treatise so much as a practical "how-to" book. It has just the right amount of science to enable a process or qualification engineer to follow the author's arguments easily. Mr Bartholomew very obviously knows his onions, as well he ought, because, as is pointed out, a large part of the work is based on his Master's thesis (Physics, University of Warwick).

My main worry about this work is its price. It is a fairly small book, one of the thinnest of the EPL range, yet it is by no means the cheapest in the famous livery of the publishers. I am not saying that it is poor value for money, but it may appear so. Granted, the subject is fairly specialised and it will never sell like an Agatha Christie, so the amortisation of the type setting and other fixed costs must be made over a relatively small number of copies. On the other hand, it would probably sell more copies if the price were fixed at a lower level.

Having got that off my chest, the book itself is divided into just seven chapters plus a glossary and, of course, an index. The first one is a short general introduction to the materials and techniques used for "glob-top" and underfill encapsulation, to provide the right background for the reader. The second is devoted to the Structure and properties of resin encapsulants. This is neatly dosed in quantity and quality, neither abstruse nor banal.

Of small importance, I cannot quite understand why Chapter 3 hops straight to Failure mechanisms in encapsulated semiconductor devices, even before the processes of encapsulation are discussed. It is rather like a doctor prescribing an aspirin to someone who has never had a headache. So be it, this chapter is reasonably comprehensive. The author hops back again to Material property requirements for encapsulant materials in the fourth chapter and then on to the Test methods for "glob-top" and underfill encapsulants, this fifth chapter being the longest and most comprehensive in the book.

Chapter 6, Processing of encapsulation and underfill materials, is possibly the least satisfying in the whole work, whilst the subject is of paramount importance, for the whole success or failure of the process is dependent on the way the materials are prepared and applied. Dispensing of the materials is rather skimmed over, for example, and little practical advice is given for the operator to optimise his process. Surface preparation to receive encapsulation is also poor and, in fact, the author refers the reader to a different book rather than allowing him to benefit from the author's own experience. There again, reference is made to obsolete standards of cleanliness which were devised long before COB was even a gleam in anyone's eye. This is a pity, because a better chapter here would have enhanced the value of the book.

The last chapter, New developments in encapsulant and underfill technology is a little more than the title may indicate. The first few pages are, indeed, what one would expect. This is followed by a list of industry standards, some of them dating back almost a decade, right in the middle, to be followed by new processing techniques, and then back to the effect of underfill performance on component reliability.

The ordering of the chapter and section subjects is really of minor importance, provided that one can find what one is looking for, and this is not difficult, once you have become used to the way the book is laid out. Furthermore, each chapter is complemented by a good set of references for those wishing to delve deeper into any specific aspect. The subject index is adequate but may have been improved by either including cited authors or having a separate index of names, such as some of the book's stablemates have.

This book certainly fills a knowledge gap, because it is probably the most comprehensive document available on this specialised subject. It is targeted towards qualification, production and process engineers, especially those who are not yet too familiar with the intricacies of the matter. As such, it can be strongly recommended, but with the reserve that the reader should not expect to find out how to set up a production line.

Brian EllisCyprus

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