Flip Chip Technologies

John H. Lau


565 pages; $89 ISBN: 0-07-036609-8

Of the three popular chip-level connection technologies, flip chip provides the highest packaging density and performance, and the lowest packaging profile. Unfortunately, it is also the least understood. This book deals with classical solder-bumped flip chip technologies, the next-generation flip chip technologies and known-good-die (KGD) testing for multi-chip module (MCM) applications.

Solder-bumped flip chip technology is described, including a new fluxless process called plasma-assisted dry soldering. Important aspects of the electrical and thermal performance of solder-bumped flip chip assemblies are discussed as well as a methodology to develop accelerated test strategies. Some test results of the thermal management, manufacturability and reliability of very large and high I/O flip chip technologies are examined. The design, development and optimization of manufacturing processes for cost-effective, large-volume assembly of flip chip are presented.

Polymer flip chip technology is overviewed along with design, process, electrical and mechanical reliability data. Polymer bump formation and metallization, assembly/rework processes, and fabrication costs are discussed. Applications of anisotropic conductive film (ACF) and adhesive (ASA) paste are described. The principle of ACF interconnects and the role of conducting particles dispersed in ACF are presented, along with the application of ACA and ACF materials to flip chip on glass technology.

Face-down wired flip chip technologies are covered along with an area array tape-automated bonding type of flip chip. Metallurgy-bumped flip chip technology is discussed as well as bumping processes and characteristics for Au, AuSn and NiAu metallurgies, and Au stud and solder-stud bumps. The final section deals with the application of flip chip technology to MCM packaging. KGD definition and standards are presented and the principles of burn in for flip chip ICs are explained.

This book is particularly aimed at individuals active in research and development of flip chip technologies, and is useful to those engineers who have encountered problems with the technology or must choose a high performance, robust and cost-effective packaging technique for their product.

Radio Propagation in Cellular Networks

Nathan Blaunstein

Artech House Inc.

386 pages; $89, £61 ISBN: 1-58053-067-2

This book examines the different situations of wireless communication in an urban environment and various propagation phenomena that influence the line-of-sight (LOS) and non-line-of-sight (NLOS) obstructive transmission of radio signals through urban communication channels. The various phenomena described include free-space propagation above regular and irregular terrain, reflection and diffraction by various obstacles regularly or randomly distributed on the terrain, and effects of scattering from such obstructions and from the ground surface. The behavior of waves at UHF and L-band frequencies is emphasized.

The book is segmented into four parts. Part one describes how to differentiate between various urban environments by using different kinds of terrain surfaces and antenna positions. Applied aspects of electromagnetism and wave propagation are discussed.

Part two describes the propagation phenomena in open and rural areas. Radio wave propagation over flat and curved smooth terrain is then discussed and propagation in rough and hilly terrain for LOS and NLOS conditions is depicted.

Part three describes propagation phenomena in built-up areas. Evaluation by means of a multi-slit street waveguide model is introduced to describe wave propagation characteristics along straight, rectangular streets in cases where both antennas, receiver and transmitter, are directly visible at lower than rooftop levels or with NLOS conditions. Irregular built-up terrain is considered and existing empirical and semi-empirical models are presented for describing propagation characteristics above rough terrain with many obstacles randomly distributed.

Part four considers special aspects of cellular map construction. The main characteristics of cellular areas are described and a useful technique for predicting the dimensions and geometry of contours of cellular maps using the propagation characteristics for each cellular channel is presented.