Assembly and Connection Technology for E-mobility Solutions and Power Electronics
For bonding semiconductors such as IGBTs, SiC MOSFETs or GaN HEMTs with Ag on DBC or AMB substrates or for connecting power modules on heat sinks, metallic sintering offers a high-performance assembly and connection technology with maximum reliability. Tresky’s sinter bonders enable the use of copper sinter paste, thixotropic silver paste, and DIE Transfer Film (DTF).
Metallic Sintering
When performing sintering, the chip is bonded to a substrate using sintering paste with the aid of heat and pressure. Typically, copper or silver sintering pastes are used. During the actual sintering process, the metal particles are bonded together by diffusion processes. The advantage over soldering processes is better thermal conductivity, longer service life and high thermomechanical stability. These properties are particularly important in electromobility and power electronics.
Precise application of the paste is the first step for a reliable, reproducible pre-sintering process in assembly and connection technology. For this purpose, Tresky uses the SQ-Nozzle developed for this purpose, which ensures a very homogeneous and large-area application of paste. The repeatability of the defined layer height or thickness is validated by an optical measurement system. After application of the sintering paste, the power semiconductor is placed within the machine in a second process step.
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Sintering with the DTF Process
During the DIE transfer film process, a thin silver sinter layer, a so-called transfer film, is first picked up with the DIE. The picked chip is pressed into the film with a defined force and temperature. When the component is subsequently lifted, a uniformly thick, defined layer is released from the film. Due to the good adhesion the layer remains adhered to the underside of the chip. The chip coated in this way is then placed on the Ag or Au pad of the DBC or AMB substrate and fed into the sintering process. After sintering, a high-purity bond is formed between the component and the surface, which exhibits excellent thermal and electrical conductivity.