Embedded passive components and PCB size – thermal effects

Abstract

The embedding of passive components such as resistors, capacitors and inductors within printed circuit boards (PCBs) is motivated, to a large extent, by the desire for increased miniaturisation of electronic goods. However, resistors and, to a lesser extent, inductors are heat generating devices, and the temperature developed within PCBs as the result of the operation of embedded passives is a significant aspect of the design of a multilayer PCB. Here we investigate, by simulation, temperature fields associated with operation of embedded resistors. It is shown that for board dimensions less than 2cm × 2cm temperatures achieved are higher than those associated with larger boards having identical structures and identical resistor heat generation. Detailed simulations are used to investigate the sensitivity of the temperature rises associated with embedded resistors to copper track coverage and to thermal coupling of the PCB to ambient on its upper and lower surfaces. The implications of these findings are discussed both in the context of the design of real PCBs and in the context of thermal simulation.

Tiny surface defect inspection of electronic passive components using discrete cosine transform decomposition and cumulative sum techniques

“…The number of passive components used in Printed Circuit Boards (PCBs) has grown to a large extent in much smaller electronic products. More than 80% of the parts in a motherboard are composed of passive components [1,2]. Also, the sizes of passive components have shrunk to 5 · 2.5 · 2.5 mm for sophisticated products [3].…”

“…There are two kinds of electronic components: (1) passive ones that contribute no power amplification in the circuit system and require only a signal to start their functions (e.g., resistors, capacitors and inductors) and (2) active ones that are capable of controlling currents and creating a switching action in the circuit (e.g., diodes, transistors and integrated circuits). As passive components require low or no power consumption, their importance and popularity have been increasing these years when energy conservation issues intensify.…”

Dielectric properties of BaTiO3/epoxy composites by lamination process for embedded capacitor application

“…These problems prevent the development of electronic products. For these reasons, it is extremely urgent to substitute the discrete components for embedded elements which exhibit superior electrical performance in electronic packaging [3,8]. Capacitors are the most commonly used passive components, which can reduce package electrical impedance and enable the system to maintain a near-constant voltage across all operating frequencies [9].…”

A case study: passive component inspection using a 1D wavelet transform

“…In recent years, the number of passive components such as resistors, capacitors and inductors within printed circuit boards (PCBs) has grown to a large extent in much smaller electrical products [1]. More than 80% of the parts in a motherboard, for example, are composed of passive components.…”

“…1. In addition, higher thermal effects are generated if the sizes of passive components are larger than the specifications since they have to be packed together [1]. Serious surface defect(s) on a solder plate (a termination) shown in Fig.…”