The last post discussed advanced leadframe packages such as the QFP and QFN and introduced the plastic ball grid array (PBGA). The second major change in packaging technology occurred in the 1990’s when surface mount technology (SMT) was displaced by area array packages to achieve higher I/O density.  This post focuses on the details of the plastic ball grid array package ... [Click to Continue...]

The last post discussed leadframe packages that were some of the first semiconductor packaging approaches.  As the need for higher chip I/O, leadframe packages with more leads were developed.  To increase the lead count, leadframes were developed to have the leads on all four sides of the molded package.  These were termed Quad Flat Packs (QFP) since the leads came off all four ... [Click to Continue...]

With the thermoset basics behind us, the next series of posts will discuss the various types of electronic packages.  There is a very specific lexicon in the electronic packaging industry and it would help the reader to first get an understanding of the rationale for the various packaging types and then provide a detailed discussion around the polymers used in these packages.  ... [Click to Continue...]

This post will provide a review of the concepts of gelation and vitrification in thermosets.  This is important in the processing of many materials used in electronic applications.  For example, epoxy mold compounds (EMC) used in a variety of electronic packaging applications are cured in the mold to just past the gel point.  As we will see, after gelation, the growing network ... [Click to Continue...]

Thermosets are unique in that during processing a chemical reaction (curing) transforms small molecules into a large crosslinked network as depicted in the schematic on the left. The use of small molecules as starting materials allows for many types of processing such as adhesive dispense, flip chip underfill, molding of epoxy mold compounds, application of protective coating ... [Click to Continue...]