Thermal effects in embedded thin- and thick-film resistors in comparison to chip resistors

Abstract

Purpose -The purpose of this paper is to investigate the thermal behaviour of thin-and thick-film resistor with different dimensions and contacts embedded into printed circuit board (PCB) and compare them to the similar constructions of discrete chip resistors assembled to standard PCBs. Design/methodology/approach -In investigations the thin-and thick-film embedded resistors with the bar form in different dimensions and configurations of contacts as well as rectangular chip resistors in package 0603 and 0402 were used. In tests were carried out the measurements of dissipated power in temperature of resistor about 408C, 708C and 1558C. The power dissipation was calculated as a multiplying of electrical current flowing through the resistor with voltage across the resistor. The dissipation of heat generated by electrical current flowing through resistors was examined by means of the FLIR A320 thermographic camera with lens Closeup £ 2 and the power source. Findings -The results show that, in case of chip resistors, the intensity of heat radiation strongly depends on dimensions of copper contact lands and also depends on the dimensions of the resistor. In case of embedded resistors, with comparable dimensions to chip resistors, they have lower ability to power dissipation, as well as the copper contact lands dimensions have lower influence. The thermal radiation through resin material is not as effective as it is in case of resistors assembled on PCB. However, the embedded thick-film resistors, especially made of paste Minico M2010, have already the similar parameters to 0402 chip resistors. Research limitations/implications -Research shows that embedded resistors can be used interchangeably with SMD resistors it allows to open up space on the surface of PCB, but it should be taken into account the lower energy dissipation capabilities. It is suggested that further studies are necessary for accurately determining the thermal effects and investigate the structures of embedded passive components that allow for better heat management. Originality/value -Thermal stability of embedded resistors during operation is a critical factor of success of embedded resistor technology. The way of power dissipation and heat resistance are one of the important operating parameters of these components. The results provide information about the power and the energy dissipation of embedded thin-and thick-film resistors compared to the standard surface mount technology.

Failure analysis of epoxy molded IC packages

“…Among them, X-ray inspection, scanning acoustic microscopy (SAM), plasma or acid etching, laser ablation or thermo-mechanical milling can be mentioned (Ardebili and Pecht, 2009; Liu et al , 2012; Shannon et al , 2010; Sylvester et al , 2013; Tang et al , 2011; Ng et al , 2012). Conventional X-ray as a common non-destructive method used in electronic industry (Sylvester et al , 2013; Sitek et al , 2015; Shannon et al , 2010; Stęplewski et al , 2014; Neubauer, 1997) can be useful to reveal, e.g. component misalignments, solder joint bridges or large cracks and voids in solder joints, but it becomes unsuitable when multi-layer samples with smaller feature size are examined.…”

Influence of thermal cycling on reliability of solder joints executed on long and metal core PCBs

“…A frequent, and serious, current problem is removing large amounts of heat from the units or the large size substrates utilized for assembly. In classic printed circuit board (PCB) technology based on epoxy glass laminate FR-4, heat dissipation of surface mount device (SMD) components to a heat sink, located on the other side of the substrate, is realized by thermal vias between the component and the heat sink (Stęplewski et al, 2014). Unfortunately, an excessive increase in the number of thermal vias reduces the mechanical strength of the material as well as reducing the surface heat dissipation.…”