Thermocompression Bonding

Author: Sascha Lohse, Ralph Schachler

Abstract: Thermocompression bonding is a quick and easy method to reliably connect flip-chips. As the name suggests, this connecting method relies on force and temperature. This means that numerous bonding processes, basically even eutectic soldering with force as used in laser bar soldering, fall into this category. In literature and among specialists, the term “thermocompression bonding” is not being used consistently, making it difficult to find an exact definition. In the following, we focus on specific thermocompression processes used in combination with gold stud bumps or Indium bumps. Bonding flip-chips with this connection methods has many advantages and shows excellent connection properties. And yet it is still a niche technology – unjustified, as this paper demonstrates! It gives a general overview of the process as well as typical process parameters. The paper also discusses common challenges of employing this technology and shows ways to overcome them with a FINEPLACER^® die bonder.