Voids in solder joints have been considered as a defect in electronics assembly. The factors that affect void formation are complex and involve the interaction of many factors. There are no established standards for void size and void area in a solder joint for it to be deemed defective. Inspection criteria have been very subjective. The effect of voids on the reliability of solder joint may de...

This paper presents three power module cooling topologies that are being considered for use in electric traction drive vehicles such as a hybrid electric, plug-in hybrid electric, or electric vehicle. The impact on the fatigue life of solder joints for each cooling option is investigated along with the thermal performance. Considering solder joint reliability and thermal performance, topologies...

The lifetime of the solder joint between base plate and ceramic substrate is usually tested by passively heating and cooling the IGBT module (thermal cycling). This provokes failures (delamination) in that solder layer. But, the IGBT and diode dies are actively heated in the application. Other failure modes (e.g. bond wire lift off) are addressed and limit the lifetime. This kind of stress is u...

Reflow soldering in a nitrogen atmosphere is a common process consideration in surface mount technology assembly. This is because the use of nitrogen in reflow equipment may benefit the process as well as the quality of the end product, where it can increase the reliability of the solder joint. So far, many papers have reported effects of cooling speed, type of solder pastes and solder fluxes o...

Reliability in flip chip and Ball Grid Array is a major concern. Solder joint geometry is extremely important from a reliability point of view. Commonly, the flip chip solder bump takes on the shape of a spherical segment. Mathematical calculations and finite element modeling have shown that the hourglass-shaped solder bumps experience the lowest plastic strain and have the longest lifetime. In...

Title of Document: AN ANALYTICAL MODEL FOR DEVELOPING A CANARY DEVICE TO PREDICT SOLDER JOINT FATIGUE FAILURE UNDER THERMAL CYCLING CONDITIONS Sony Mathew, Ph.D., 2015 Directed By: Professor Michael G. Pecht , Department of Mechanical Engineering Solder joint fatigue failure is a prevalent failure mechanism for electronics subjected to thermal cycling loads. The failure is attributed to the the...

In this paper; we described an approach to automation of visual inspection of BGA solder joint defects of surface mounted components on printed circuit board by using neural network. Inherently, the BGA solder joints are located below its own package body, and this induces a diflculty of taking good image of the solder joints by using conventional imaging system. To acquire the cross-sectional ...

The integration and miniaturization trend of the electronic packaging leads to much finer pitch of the device and package lead terminations. Several reliability concerns and issues that were previously not encountered are now surfacing. The objective of this thesis work is to investigate the reliability of the package-to-board interconnection from the perspective of solder joint metallurgy. It ...

Purpose: Computer vision has been widely used in the inspection of electronic components. This paper proposes a computer vision system for the automatic detection, localisation, and segmentation of solder joints on Printed Circuit Boards (PCBs) under different illumination conditions. Design/methodology/approach: An illumination normalization approach is applied to an image, which can effective...

Plastic-ball-grid-array (PBGA) packages were assembled onto FR-4 printed-circuit-boards (PCBs) using lead-free SnAgCu solder, different solder pad diameters, stencil thicknesses and reflow peak temperatures, and the effects of the design and assembly process conditions on the dimensions and reliability of the solder joints were investigated. The assembled microelectronic devices were subjected ...