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Notes: The advances in miniaturisation and ever increasing complexity of integrated circuitsfrequently mean an increase in the number of connections to a component with simultaneous reductionin pitch. For these emerging smaller contact geometries, micro-laser connection technologies arerequired. The reliability of the connection plays a decisive rôle. Theimplementation and reproducibility of laser connections technology in micro-electronics depend ongood thermal contact between the two parts and high quality absorption of the material surface used. Laser energy can cause local melting due to overheating of the lead becauseof the low distance between lead and bump. This effect influences the reproducibility of the contacts.Even the slightest interruption in the thermal contact of the parts cancause non-reproducibility of the contacts. Materials with a higher quality of absorption, for exampleSn(32% ), can be soldered with a good level of reproducibility. This clearly differs from gold (4% ) orcopper(7% ) surfaces. Due to the low absorption of these materials it is necessary to use a laserwith a higher intensity to produce the same energy. Irregularities in the quality of absorption, laserinstability and thermal contact can not guarantee reproducibility of the interconnections with this highlaser intensity. The FPC (fibre push connection) system offers severalsolutions to the problems mentioned. This system enables the laser to be transported by fibre to thecontact parts. The end piece of the fibre serves at the same time as a pushing unit. The advantage of this system is that the attenuation heat of the fibre end surface is alsoavailable for the connection. This improves the use of laser energy. As part of the laser energy at theend surface of the fibre is transformed into thermal energy, independently of the absorption quality ofthe material used, connection of a gold-plated contact part is possible. By pressing the connecting partswith the tip of the fibre, optimal coupling is achieved. The reproducibility of different metallisations and the reliability of connections with a pitchbelow 100 µm are presented as well as further applications of this system.

Notes: During the last few years an increasing number of flip-chip (FC) interconnection technologies have emerged. While flip-chip assembly offers many advantages compared with conventional packaging techniques, several aspects prevent this technology from entering the high volume market. Among these are theavailability of bumped chips and the costs of the substrates, i.e., ceramic substrates withclosely matching coefficient of thermal expansion (CTE) to the chip, in order to maintain highreliability. Only recently, with the possibility of filling the gapbetween chip and organic substrate with an encapsulant, was the reliability of flip-chipsmounted on organic substrates significantly enhanced. This paperpresents two approaches to a fluxless process, one based on soldering techniques using Au-Snmetallurgy and the other on adhesive joining techniques. Soldering is performed with athermode and with a laser based system. For both of these FC-joining processes, alternativebump mettallurgies based on electroplated gold, electroplated gold-tin, mechanical gold andelectroless nickel gold bumps are applied.