Prediction of Solder Geometry for an Axisymmetric Through-Hole Joint

1997 ◽  
Vol 119 (4) ◽  
pp. 268-274 ◽  
Author(s):  
A. F. Elkouh ◽  
N. Ramasubramanian ◽  
T. F. Hsu ◽  
N. J. Nigro ◽  
S. M. Heinrich ◽  
...  
Keyword(s):  
Differential Equation ◽  
Printed Circuit Board ◽  
Solder Joints ◽  
Bond Number ◽  
Circuit Board ◽  
Dimensionless Parameters ◽  
Printed Circuit ◽  
Board Thickness ◽  
Solder Volume ◽  
Through Hole

Solutions for axisymmetric profiles of solder joints formed between a cylindrical pin and a printed circuit board (PCB) are presented. The dimensionless differential equation governing the formation of the solder joints is developed and then solved numerically for the cases of single upright joints, single inverted joints, and through-hole joints. Results are presented in terms of the following dimensionless parameters: bond number, solder volume, board thickness, and tinning radius. The dimensionless approach makes the results from this study suitable for use in a broader range of applications.

Thermal Model of Printed Circuit Board Plated-Through Hole under One-Sided Heating Conditions

2021 ◽  
Vol 26 (5) ◽  
pp. 426-431
Author(s):  
V.A. Sergeev ◽  
◽  
A.M. Khodakov ◽  
M.Yu. Salnikov ◽  
◽  
...  
Keyword(s):  
Quality Control ◽  
Thermal Resistance ◽  
Thermal Model ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Thermal Models ◽  
Printed Circuit ◽  
Plated Through Hole ◽  
Through Hole

Thermal methods of quality control of the plated-through hole (PTH) of printed circuit board (PCB) are based on thermal models. However, known thermal models of PTH take no account of heat transfer to PCB material thus not allowing for PTH heat characteristic tying up with adhesion quality. In this work, an axisymmetric thermal model of a single-layer PCB PTH under one-sided heating conditions is considered. It was shown that the ratio of the temperature increments of the upper (heated) and lower end of the PTH in the considered range of heating power does not depend on the power level. A linear thermal equivalent scheme of the PTH has been proposed, which includes the longitudinal thermal resistance of the PTH metallization, de-termined by the parameters and quality of the metallization layer, the thermal resistance, which determines the convection heat exchange between the ends of the PTH with the adjacent PCB surface and the environment, and the thermal resistance of the area of the PCB material adjacent to the PTH, depending on the quality of the metallization adhesion and the PCB dielectric. Thermal equivalent circuit parameters determined by the ratio of the temperature increment of the upper and lower ends of the PTH and their difference can serve as the basis for the development of a nondestructive inspection procedure for PTH quality control by way of its unilateral heating, for example, by a laser beam.

Modeling of Errors Counting System for PCB Soldered in the Wave Soldering Technology

2014 ◽  
Vol 874 ◽  
pp. 139-143 ◽  
Author(s):  
Jacek Pietraszek ◽  
Aneta Gądek-Moszczak ◽  
Tomasz Toruński
Keyword(s):  
Quality Assurance ◽  
Experimental Design ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Counting System ◽  
Printed Circuit ◽  
Pcb Assembly ◽  
Wave Soldering ◽  
Soldering Technology ◽  
Through Hole

PartnerTech provides printed circuit board (PCB) assembly on request. Wired elements are assembled in through-hole technology and soldered on the wave soldering machine. The PCB with inserted elements is passed across the pumped wave of melted solder. Typically this process is accompanied by some class of defects like cracks, cavities, wrong solder thickness and poor conductor. In PartnerTech Ltd. another type of defects was observed: dispersion of small droplets of solder around holes. Quality assurance department plans to optimize the process in order to reduce the number of defects. In the first stage, it was necessary to develop a methodology for counting defects. This paper presents experimental design and analysis related to this project.

High-Speed Cyclic Bend Tests and Board-Level Drop Tests for Evaluating the Robustness of Solder Joints in Printed Circuit Board Assemblies

2009 ◽  
Vol 38 (6) ◽  
pp. 884-895 ◽  
Author(s):  
E.H. Wong ◽  
S.K.W. Seah ◽  
C.S. Selvanayagam ◽  
R. Rajoo ◽  
W.D. van Driel ◽  
...  
Keyword(s):  
High Speed ◽  
Printed Circuit Board ◽  
Solder Joints ◽  
Circuit Board ◽  
Printed Circuit ◽  
Drop Tests ◽  
Bend Tests ◽  
Board Level

Thermal Fatigue Damage in the Solder Joints of Leadless Chip Resistors

1994 ◽  
Vol 116 (2) ◽  
pp. 83-88 ◽  
Author(s):  
R. K. Govila ◽  
E. Jih ◽  
Y.-H. Pao ◽  
C. Larner
Keyword(s):  
Stress Concentration ◽  
Fatigue Damage ◽  
Thermal Fatigue ◽  
Critical Stress ◽  
Printed Circuit Board ◽  
Solder Joints ◽  
Circuit Board ◽  
Printed Circuit ◽  
Modeling Analysis ◽  
Leadless Chip Resistors

Leadless chip resistors (LCR) made by two different manufacturers and surface mounted on glass/epoxy printed circuit board (PCB) were subjected to thermal cycling between −55°C to 125°C in order to induce thermal fatigue failure/damage. The test units were subjected to a maximum of 250 thermal cycles. Solder joints in both types of LCRs were examined in scanning electron microscope and a relative comparison of the extent of fatigue damage is presented. The failure mechanism is associated with cracking in the eutectic compostion Sn/Pb solder initiated at the stress concentration sites. A nonlinear, time-dependent finite element modeling analysis has been performed to determine critical stress concentration sites in the solder joint. Key parameters leading to the initiation of solder damage are identified, and recommendations are made to improve the design in terms of solder configuration such as the radius of corner of the alumina substrate and the standoff height.

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