Guest Post by Huan Lee, Lambient Technologies The dielectric response of thermosets and resins depends on a number of factors that vary with frequency, so it is important to select an optimum frequency for dielectric cure monitoring (DEA). To inform this choice, we must look at the material property most directly related to cure state, which is frequency independent ... [Click to Continue...]

Guest Post by Huan Lee, Lambient Technologies Instead of ion viscosity (electrical resistivity), many users of older cure monitoring equipment measure a material’s conductance and plot the results on a linear scale. Why conductance? Why a linear scale? Because that is an old-school method based on advice from the equipment’s manufacturer. In this post I want to how a linear ... [Click to Continue...]

Guest Post by Huan Lee, Lambient Technologies One advantage of dielectric cure monitoring (DEA) is the ability to observe rapid polymerization of UV curable adhesives like H.B. Fuller U3345, [Ref. 1] the topic of this post. In this case the use of techniques such as DSC is not possible, or at least very difficult. But with DEA the electrical resistivity, or ion viscosity, is ... [Click to Continue...]

Guest Post by Huan Lee, Lambient Technologies In the first post of this series, we saw in theory how ion viscosity changes as a thermoset cures, and how Critical Points can characterize the cure. Now let’s see how epoxy molding compound cures in reality. Samples of EMC were placed on a Lambient Technologies 1” Unitrode Sensor [Ref. 1], shown in Figure 1, then were compressed ... [Click to Continue...]

Guest Post by Huan Lee, Lambient Technologies Normally available in either B-staged powders or pellets for transfer molding, epoxy molding compound (EMC) is essential for electronics packaging and is used to encapsulate billions of integrated circuits each year. Figure 1. Granular (left) and pelletized (right) epoxy molding compound [Ref. 1] During cure of EMC, when ... [Click to Continue...]