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In this paper, a generic four-parameter model has been developed and applied to the anisotropic conductive adhesive (ACA) flip-chip joining technology for electronics packaging applications. The model can also be used to predict any minimum failure cycles if the maximum acceptable failure criterion (in this case, a preset electrical resistance value) is set. The original reliability testing from which the test data was obtained was carried out on flip-chip anisotropically conductive adhesive joints on an FR-4 substrate. In the study, nine types of ACA and one nonconductive film (NCF) were used. In total, nearly 1000 single joints were subjected to reliability tests in terms of temperature cycling between -40/spl deg/C and 125/spl deg/C with a dwell time of 15 min and a ramp rate of 110/spl deg/C/min. The reliability was characterized by single contact resistance measured using the four-probe method during temperature cycling testing up to 3000 cycles. A single Weibull model is used for two failure definitions defined as larger than 50 m/spl Omega/ and larger than 100 m/spl Omega/ respectively using the in situ electrical resistance measurement technique. The failure criteria are incorporated into this Weibull model. This paper shows the flexibility and usefulness of Weibull distribution in this type of applications.

This work focuses on uncertainty analysis, that is, how the input data uncertainty affects the output data uncertainty in small but realistic product systems. The motivation for the study is to apply the Monte Carlo simulation for uncertainty estimation in life cycle inventory and environmental assessment of microelectronics applications. The present paper addresses the question whether there is an environmental advantage of using digital enhanced cordless telecommunications (DECT) phones instead of global system for mobile (GSM) phones in offices. This paper also addresses the environmental compatibility of electrochemical pattern replication (ECPR) compared to classical photolithography-based microscale metallization (CL) for pattern transfer. Both environmental assessments in This work consider electricity consumption and CO/sub 2/ emissions and the projects undertaken are two comparative studies of DECT phone/GSM phone and ECPR/CL, respectively. The research method used was probabilistic uncertainty modeling with a limited number of inventory parameters used in the MATLAB tool. For the DECT/GSM study the results reflects the longer DECT technical life which is an environmental advantage. For the electrochemical pattern replication (ECPR)/classical photolithography based microscale metallization (CL) study the results reflects the fewer number of process steps and the lower electricity consumption needed by the ECPR to reach the functional unit. The difference in results is large enough to be able to draw conclusions, as the processes, having the highest electricity consumption within the system boundaries have been determined. Based on an earlier work, a straightforward method to include uncertainty for input life cycle inventory data is used to quantify the influence of realistic errors for input data in two microelectronic applications. The conclusion is that the ECPR technology is more electricity efficient than CL in producing one layer of copper on a silicon wafer having a diameter of 20.32 cm. Furthermore, the longer technical life of a cordless DECT phone is reflected in an electricity/CO/sub 2/ comparison with a GSM phone, if office use is considered. Reasonable uncertainty intervals, used for the input life cycle inventory data for the studied DECT/GSM and ECPR/CL system, does affect the outcome of calculation of emission of CO/sub 2/, but not to the degree that conclusions are not valid. Different uncertainty intervals and probability distributions could apply for different types of data and the interrelated input data dependencies should be investigated. Today there exist very few life cycle inventory (LCI) data with the range of uncertainty for input and output elements. It must be emphasized that the upcoming LCI databases should have standard deviation characterized LCI data just as the Swiss ecoinvent LCI database. More inventory parameters and probability distributions characteristic for microsystems could be included and error analysis should be applied to future life inventory methodology, especially for future packaging concepts such as system-in-a-package and system-on-a-chip comparisons.

Liquid crystal polymer (LCP) has potentially a very wide application as substrate material in electronic packaging applications because of its unique advantages. The work in this paper was performed to realize the metallization of LCP for the purpose of board fabrication, and to study the adhesion between deposited copper and LCP. A homogenous electroless plated copper layer on LCP with 4 to 5 /spl mu/m thickness was achieved, while it increased up to 40 /spl mu/m with the subsequent electroplating. The timescale of etching, deposit ion rate, and pH value were gradually changing during the plating process and the influences on copper layer quality were investigated. The adhesion force of the copper-LCP layer system was measured by a shear-off-method. Scanning electron microscopy (SEM) was used to check the surface morphology after etching and the interface after shearing on both the backside of the copper layer and the LCP side. The relationship between the shear-off adhesion of copper and the time of chemical etching before plating was examined, and the optimal etching time is discussed. Heat treatment after plating was used, and it was shown that this significantly improved the adhesion strength.

The present work is to introduce nanoparticles in micro-sized metal particles to study particle distribution in polymer matrix. Previous examinations of the silver-filled particles reveal that the micro-sized particle fillers appear as full density silver flakes, while nanoparticle fillers appear as highly porous agglomerates, similar to open-cell foams. Actually little work has been carried out to study the cross-sectional area of a particle-particle-contact in isotropically conductive adhesives (ICA). In this study, transmission electron microscope is chosen as a main measure to analyze the distribution of different-sized particles. The percentage of the nanoparticles varies from 20 wt% and 50 wt% to full percentage within micro-sized particles, and the total metal content in epoxy resin is 70 wt%. So the change of contact area and contact behavior with various volume ratio of nano-sized and micro-sized particles was investigated. At the same time, the electrical resistivity was measured, which is compared with the different level of the filler loading.