UCD-FIT houses a Finetech ”Fineplacer Pico ma” aligner-bonder which is a multipurpose die bonder with 5 m accuracy and repeatability. A single camera views both the substrate and package simultaneously using a rigid beam splitter. Engineered stability of the design guarantees that once the substrate material’s position and angle visually overlaps that of the upper die, this orientation is maintained throughout the process of rotating the die with respect to the substrate and bonding them. The other critical ability for the flip chip bonder is to ensure coplanarity of the sample as it is brought into contact with the sensor wafer. Even an angular discrepancy of only 0.1° across the length of roughly a 1 cm long chip will create a height difference of 35 m.
General Bonding Procedure:
Gold Stud Bump Bonding
Gold stud bump bonding is the bread and butter of our bonding operations. While single-stud bonding is quite commonplace in industry, we have developed a novel double stud bonding technique that requires less pressure and a lower temperature for bonding delicate chips. A recent paper has been published regarding double gold stud bump bonding (Further Developments in Gold-stud Bump Bonding).
To create the double gold stud bond, two dummy chips were studded with gold balls. Next, both were coined at room temperature. Then, the bond was performed.
Un-coined (left) and coined gold studs (right).