The investigation of the grain structure of Cu/SnAg interconnects produced by solid-liquid interdiffusion (SLID) bonding is presented in this study. The texture analysis was carried out using Electron Backscatter Diffraction (EBSD). The samples were manufactured by flux-assisted bonding of two Si dies with an area array of square Cu/SnAg bumps on the bottom die and square Cu bumps on the top die at a temperature of 250°C and bonding time between 35 s and 40 s. The influence of the bonding process carried out under pressure of 1.73 MPa and without pressure on the orientation of the Cu6Sn5 grains is shown. The preferred grain orientation of Cu6Sn5 is <0001> parallel to the sample direction [010] (growth direction of the intermetallic compounds (IMCs), perpendicular to Cu surface). This texture decreases with the application of bonding pressure. The Cu grains show the preferred directions <101> and <111> parallel to the electroplating direction

We present a "carrierless" design for the manufacturing of ultrathin Silicon wafers, which are used in e.g. TSV (Through Silicon Via) and power chip applications. A carrierless wafer is a wafer which has a thinned inner portion, usually thinner than 150 m, and a rim portion, which is stabilizing the wafer, so that the whole wafer can be handled without any additional support. In more detail, progress on 300 mm carrierless wafers and its compatibility with standard applications like RDL (Redistribution Layer) and bumping will be discussed

The investigation of the bonding pressure change on the different quality aspects of the solid-liquid interdiffusion (SLID) interconnects is presented. The stacks were produced by a flux-assisted bonding of two Si dies with an area array of square Cu/SnAg bumps on the bottom die and Cu bumps on the top die at approx. 250 °C. The bonding pressure was varied between 0 MPa, 0.35 MPa, 0.69 MPa, 1.04 MPa, 1.38 MPa, 1.73 MPa, 2.08 MPa, 2.42 MPa. Cross-sections of the stacks were analyzed by optical microscopy and scanning electron microscopy (SEM). Tilt, standoff height (SOH) variation, void fraction, interlayer thickness and Cu3Sn thickness were measured. It will be shown that increase of the bonding pressure can reduce the void fraction from 35.1 % (0 MPa) to 10.7 % (2.42 MPa) and decrease the interlayer thickness at the same time. Decrease of the interlayer thickness is accompanied by solder squeeze and increase of Cu3Sn thickness. Shear tests revealed an average shear str ength of (81.3 ± 21.5) MPa for the produced samples. The analysis of the fracture surfaces with SEM revealed that the weakest interface is located between Cu6Sn5 and Cu3Sn intermetallic compounds (IMCs) close to the initial Cu bump