The rheological properties of polymers used in electronic packaging applications spans a wide range of fluid types and viscosity ranges.  In the uncured state, many adhesives, coatings, mold compounds, and underfills have interesting rheological behavior.  Many of these types of materials are highly filled to achieve the desired mechanical properties such as low coefficient of ... [Click to Continue...]

I will start this post with a short personal story about how I got into electronic packaging and specifically, rheology in electronic packaging.  When I was a fourth year graduate student at Northwestern I started looking for a job at the typical places an industrial polymer rheologist might consider, like Dow, DuPont, GE Plastics and others.  My thesis advisor, Prof. William ... [Click to Continue...]

Figure 1.  Build-up material roadmap (source: Ajinomoto Fine-Techno Co. Inc.) The last post described the chemistry and types of build-up films typically used in the electronic packaging industry.  We also touched on the build-up material roadmap which showed the various complex packaging substrates that are enabled using build-up film technology as shown in Figure 1.  ... [Click to Continue...]

Figure 1. Cross section of a 1+4+1 HDI substrate using Ajinomoto build-up film (ABF) The previous post discussed the geometry of the ABF products and the process used to build-up the circuit layers on the core.  In Figure 1 above, there is one layer of ABF on each side of the 4 layer BT epoxy core.  Notice in this schematic construction the plated through holes (PTH) extend ... [Click to Continue...]