In epoxy die bonding and any related die attach processes, the accurate placement and attachment of the die is crucial for process stability and the resulting component quality. The adhesive thickness or also bond line thickness (BLT) is key for a reliable die attach to a lead frame or other substrates. TopMap surface profilers from Polytec allow an automatic and reliable determination of the die orientation on the lead frame including the die tilt as well as bond line thickness measurement. This non-contact measuring method enables a fast, simple and reliable quality control of the die bonding process.
Characterizing QFN packages (quad-flat no-leads)
3D surface metrology solutions from Polytec are easy to integrate into production lines and provide automated and high resolution in-process measurement in expoy die bonding processes. Typical measurements are the determination of the die tilt, the bond line thickness measurement (BLT), the BLT height or die/ chip positioning as well as torsional information and relative measurement to a reference position.
In quad-flat no-leads (QFN) packages as one of the typical chip connect types in integrated circuits, the die attach fillet is an excess climbing on the edge of the die. It provides mechanical strength along the die edges. Based on the measured bond line thickness, the useful and optimized parameters can be derived, such as width of the fillet, height of the fillet from the pad, slope of rise of the fillet or the slope angle.