The Use of Scatter Plot Charts for the Study of Changes in the Electrical Parameters of Conductive Adhesive Joints

For adhesive conductive joints, the most frequently measured electrical parameters are the resistance of the joint, the non-linearity of the volt-ampere characteristic of the joint, and its 1/f noise. The work is focused on the question of whether it is possible, based on a scatter chart, to estimate the changes of one parameter under a certain type of climatic stress from the changes of the same parameter under another type of climatic stress, and also on the question of whether it is possible, based on a scatter plot, to estimate the changes of one of a parameter induced by one type of climatic stress from changes in another parameter induced by the same type of stress. It was found that the first question can be answered in the affirmative and the second in the negative. Strong correlations were found for both adhesives. For Adhesive #1, it was between the change in non-linearity of the volt-ampere characteristic in wet aging and combined wet-heat aging. Another significant correlation was found here between the change in non-linearity of the volt-ampere characteristic and the change in 1/f noise during wet aging. For adhesive #2, a strong correlation was found between the change of the resistance during the exposition of the joints in higher moisture and heat. Next strong correlation was also found between the resistance and non/linearity of the joint for aging in combined climate moisture-heat. Based on the mentioned correlations, it is possible to construct scatter plot charts which can be used to make especially long-term climate tests of conductive adhesives more efficient.