Root Cause Analysis of a Connector Time-Delayed Fracture

2015 ◽  
Author(s):  
Prabjit Singh ◽  
Ying Yu ◽  
Robert E. Davis
Keyword(s):  
Printed Circuit Board ◽  
Ceramic Substrate ◽  
Circuit Board ◽  
Delayed Fracture ◽  
Ceramic Substrates ◽  
Printed Circuit ◽  
Root Cause ◽  
Chip Carrier ◽  
Electrical Connections ◽  
Grain Boundary Grooves

Abstract A land-grid array connector, electrically connecting an array of plated contact pads on a ceramic substrate chip carrier to plated contact pads on a printed circuit board (PCB), failed in a year after assembly due to time-delayed fracture of multiple C-shaped spring connectors. The land-grid-array connectors analyzed had arrays of connectors consisting of gold on nickel plated Be-Cu C-shaped springs in compression that made electrical connections between the pads on the ceramic substrates and the PCBs. Metallography, fractography and surface analyses revealed the root cause of the C-spring connector fracture to be plating solutions trapped in deep grain boundary grooves etched into the C-spring connectors during the pre-plating cleaning operation. The stress necessary for the stress corrosion cracking mechanism was provided by the C-spring connectors, in the land-grid array, being compressed between the ceramic substrate and the printed circuit board.

Temperature and Humidity Dependent Reliability Analysis of RGB LED Chips

2006 ◽  
Author(s):  
Jun-Xian Fu ◽  
Shukri Souri ◽  
James S. Harris
Keyword(s):  
Reliability Analysis ◽  
Printed Circuit Board ◽  
Light Emitting Diode ◽  
Circuit Board ◽  
Light Emitting ◽  
Printed Circuit ◽  
Root Cause ◽  
Micro Cracks ◽  
Temperature And Humidity

Abstract Temperature and humidity dependent reliability analysis was performed based on a case study involving an indicator printed-circuit board with surface-mounted multiple-die red, green and blue light-emitting diode chips. Reported intermittent failures were investigated and the root cause was attributed to a non-optimized reflow process that resulted in micro-cracks and delaminations within the molding resin of the chips.

Printed Circuit Board Propagating Faults

2004 ◽  
Author(s):  
Daren T. Slee
Keyword(s):  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Fault Tree Analysis ◽  
Circuit Board ◽  
Circuit Boards ◽  
Visual Examination ◽  
X Ray ◽  
Printed Circuit ◽  
Root Cause ◽  
X Ray Imaging

Abstract This paper is a review of propagating faults in printed circuit boards (PCBs) from the perspective of using the resulting burn and melted copper patterns to identify likely locations of fault initiation. Visual examination and x-ray imaging are the main techniques for examining PCB propagating faults. Once the likely fault initiation location has been identified, fault tree analysis can be used to determine the root cause for fault initiation. The paper discusses the mechanisms by which PCB propagating faults occur. The method of determining the likely area of initiation of the fault using visual examination of the PCB burn pattern, x-ray imaging, and the layout artwork for the PCB is discussed. The paper then goes on to discuss possible root-causes for the initiation of PCB propagating faults and some of their considerations.

scholarly journals Root Cause Analysis of a Printed Circuit Board (PCB) Failure in a Public Transport Communication System

2022 ◽  
Vol 12 (2) ◽  
pp. 640
Author(s):  
Cher-Ming Tan ◽  
Hsiao-Hi Chen ◽  
Jing-Ping Wu ◽  
Vivek Sangwan ◽  
Kun-Yen Tsai ◽  
...  
Keyword(s):  
Printed Circuit Board ◽  
Failure Modes ◽  
Essential Element ◽  
Circuit Board ◽  
Cause Analysis ◽  
Printed Circuit ◽  
Root Cause ◽  
Burn Out ◽  
Root Cause Identification

A printed circuit board (PCB) is an essential element for practical circuit applications and its failure can inflict large financial costs and even safety concerns, especially if the PCB failure occurs prematurely and unexpectedly. Understanding the failure modes and even the failure mechanisms of a PCB failure are not sufficient to ensure the same failure will not occur again in subsequent operations with different batches of PCBs. The identification of the root cause is crucial to prevent the reoccurrence of the same failure. In this work, a step-by-step approach from customer returned and inventory reproduced boards to the root cause identification is described for an actual industry case where the failure is a PCB burn-out. The failure mechanism is found to be a conductive anodic filament (CAF) even though the PCB is CAF-resistant. The root cause is due to PCB de-penalization. A reliability verification to assure the effectiveness of the corrective action according to the identified root cause is shown to complete the case study. This work shows that a CAF-resistant PCB does not necessarily guarantee no CAF and PCB processes can render its CAF resistance ineffective.

Case Study—Failure Analysis of a Printed Circuit Board Latent Failure and Resulting Implication of Weaknesses in Panel Coupons and Lot DPA

2017 ◽  
Author(s):  
Tom Tuite
Keyword(s):  
Failure Mechanism ◽  
Printed Circuit Board ◽  
Short Circuit ◽  
Circuit Board ◽  
System Level ◽  
Drilling Process ◽  
Printed Circuit ◽  
Root Cause ◽  
Ionic Contamination ◽  
Root Cause Identification

Abstract Multiple, independent, system level test failures that occurred around the same time were traced back to a short circuit on the same type of printed circuit board (PCB). The PCBs were removed from the application and sent to the authors' lab for analysis. This paper reviews the analysis techniques and results that led to the failure mechanism being identified. The discussion focuses on steps taken to exonerate the authors' lab and processes as possible sources of contamination. Additional investigation that leads to the conclusion that the issue is systemic is also covered. The paper then focuses on the containment effort as well as root cause identification at the manufacturers. It was concluded that the failure mechanism causing the short circuit in the failed PCB is due to ionic contamination trapped inside the PCB. The normal chemistry required to process the plated through holes contaminated the voids/fractures created by drilling process.

A Novel Approach to Identifying and Validating Electrical Leakage in Printed Circuit Boards Through Magnetic Current Imaging

2004 ◽  
Author(s):  
Craig Hillman
Keyword(s):  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Ground Plane ◽  
Circuit Board ◽  
Magnetic Current ◽  
Printed Circuit ◽  
Root Cause ◽  
Low Leakage ◽  
Novel Approach ◽  
Failure Site

Abstract Superconducting Quantium Interferance Device (SQUID) microscopy uses detection of magnetic fields to image current paths within electronic devices and has been successful in non-destructively identifying the location of low leakage currents, even when the failure site was between a power and ground plane. This article presents a case study in which the customer was experiencing ignition of a 20-layer printed circuit board after approximately 1000 to 4000 operating hours in an indoor-controlled environment. High currents on the board resulted in extensive damage, effectively preventing initial identification of the failure site, failure mechanism, or root-cause. Based on a review of potential failure mechanisms, measurement of relevant parameters, and the results of SQUID microscopy, the process of electrochemical migration around or through the particles was determined to be the most likely root-cause of electrical shorting between power and ground.

Debonding in Overmolded Integrated Circuit Packages

1993 ◽  
Vol 115 (3) ◽  
pp. 249-255 ◽  
Author(s):  
S. Hunt ◽  
L. A. Carlsson
Keyword(s):  
Finite Element ◽  
Integrated Circuit ◽  
Printed Circuit Board ◽  
Interfacial Stress ◽  
Circuit Board ◽  
Electronic Packages ◽  
Printed Circuit ◽  
Finite Element Stress Analysis ◽  
Failure Loads ◽  
Chip Carrier

Recently introduced overmolded pad array chip carrier (OMPAC) electronic packages sometimes suffer from debonding between the overmold material and the printed circuit board. In this study, bond strength is characterized by a combination of experimental and analytical methods. Test specimens representative for OMPAC structures were designed, manufactured, and tested to failure in tension and torsion. Finite element stress analysis of the specimens was performed in conjunction with a combined interfacial stress failure criterion to determine interfacial tensile and shear strengths from the measured failure loads.

Characteristics of Radiated Emission from a Printed Circuit Board with a Slit

2012 ◽  
Vol 132 (6) ◽  
pp. 404-410 ◽  
Author(s):  
Kenichi Nakayama ◽  
Kenichi Kagoshima ◽  
Shigeki Takeda
Keyword(s):  
Printed Circuit Board ◽  
Circuit Board ◽  
Printed Circuit ◽  
Radiated Emission

Confirming the Signal Integrity in Transmission of Digital Signals on Microstrip Straight Circuits via the Eye Diagrams

2014 ◽  
Vol 5 (1) ◽  
pp. 737-741
Author(s):  
Alejandro Dueñas Jiménez ◽  
Francisco Jiménez Hernández
Keyword(s):  
Integrated Circuits ◽  
Printed Circuit Board ◽  
Signal Integrity ◽  
High Volume ◽  
Information Storage ◽  
Circuit Board ◽  
Electromagnetic Simulation ◽  
Electronic Systems ◽  
Digital Signals ◽  
Printed Circuit

Because of the high volume of processing, transmission, and information storage, electronic systems presently requires faster clock speeds tosynchronizethe integrated circuits. Presently the “speeds” on the connections of a printed circuit board (PCB) are in the order of the GHz. At these frequencies the behavior of the interconnects are more like that of a transmission line, and hence distortion, delay, and phase shift- effects caused by phenomena like cross talk, ringing and over shot are present and may be undesirable for the performance of a circuit or system.Some of these phrases were extracted from the chapter eight of book “2-D Electromagnetic Simulation of Passive Microstrip Circuits” from the corresponding author of this paper.

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