| Résumé : |
The joining technique "bonding" has become more and more important in electronics. The reason for this is the trend towards miniaturization of modules, structural components and end products. The task of bonding very different materials onto a minimum of space securely, permanently and economically makes the usage of classical joining techniques, such as screwing, riveting or welding, nearly impossible. The adhesive, however, which is optimally adjusted to the application, is ideal.
Due to the globalization of markets and the trend towards outsourcing, the image of modern production firms is dominated more and more by industrial mass production. This leads towards the demand for adhesive applications to be served by products that enable mass production with very short cycle times. Photo-initiated adhesives fulfill this requirement perfectly.
Recently, significant successes have been achieved in the development of light-curing acrylates and light-activated epoxies. These products are particularly suitable for industrial production applications, where their rapid curing characteristics allow short cycle times. At the same time, these materials meet the increasing requirements of the electronics industry for electrical and thermal properties as well as chemical and corrosion resistance.
Additionally, initiation with radiation in the visible spectrum allows the curing of these materials in applications where it needs to be cured through transparent plastics, such as PMMA, PC or PVC. Due to the absorption of ultraviolet radiation by such plastics, this cannot usually be achieved by standard UV-curing adhesives.
Different adhesive systems with their curing mechanisms and characteristics will be introduced. By comparing different development stages, the outstanding properties of the latest generation of these adhesives are seen. By way of several examples, the possibilities of commercial mass production in the electronics industry can be demonstrated. As a result of research and development activities, products can be offered which have, apart from the features mentioned previously, good adhesive and cohesive strenght together with high flexibility. |
Aller sur edunet
Accueil
Big things in small packages in ADHESIVES AGE, Vol. 45, N° 3 (03/2002)
