The Application of a Type of Electric Pastern in the Bonding Technique of the Microcircuit Board

Abstract

The authors have performed experiments in the felting of electric pasterns upon the samples of aluminum alloy boards, gold-plating boards and glass strips, the method of which is to first felt 2 microcircuit boards with electric pastern and fix them with some mechanical devices, then keep them in the drying blast oven for 4 hours with a constant temperature of 150plusmn2degC and finally, cool them naturally to the ambient temperature. The series of experiments made include the testing of the extension and cutting intensity of the electric pastern, the testing of the volume resistivity of the electric pastern and the experiment of the concussion given to the electric pastern at relatively high or low temperatures, the purpose of which is to test the reliability of its felting quality and further to study the application of the electric pastern in the bonding technique of the microcircuit board. Obtained from the testing of extension intensity carried out with the relevant testing machine according to GB7124- 86, the testing value of aluminum alloy board is between 5.5M Pa and 6.99 M pa, the testing value of the gold-plating board is from 2.45M Pa to 3.07M Pa, which clearly mean that the joining intensity of electric pastern to aluminum alloy board is better than that to the gold-plating board. However, both intensities have met our demands and are acceptable. We also have tested the volume resistivity of the glass strips connected to it. Since for the bonding technique of the microcircuit board, it is usually acceptable if the resistivity of the electric pastern is less than 9.0 X10"4 Q.cm, our testing data have shown that the quality of this type of electric pastern is satisfactory. Having fulfilled the concussion test for the microcircuit board at relatively high or low temperatures, we have tested the reliability of the bonding points. The finding shows that the change of the resistivity of the microcircuit board is within very small scale, and if assigned to every felting point, the change can simply be ignored, thus cannot affect the felting quality at all. To sum up, the series of experiments have given the proof that this type of electric pastern meets the requirements of the bonding technique of the microcircuit board connected by gold threads or gold bands.