Heteromolecular H –bond interaction forces and dielectric parameters: Time domain reflectometry studies

2022 ◽  
Vol 787 ◽  
pp. 139272
Author(s):  
P. Dineshkumar ◽  
R. Sahana ◽  
R. Shanmugam ◽  
A. Elangovan ◽  
R.K. Sankaranarayanan ◽  
...  
2017 ◽  
Vol 07 (04) ◽  
pp. 1750027 ◽  
Author(s):  
M. Maria Sylvester ◽  
T. Ganesh ◽  
D. J. S. Anand Karunakaran ◽  
P. Senthilkumar ◽  
Praveen G. Hudge ◽  
...  

Dielectric permittivity and relaxation dynamics of binary and ternary mixture of stearic acid on various concentration and their thermodynamic effects are studied. The static dielectric constant ([Formula: see text]), dielectric permittivity ([Formula: see text]) and dielectric loss ([Formula: see text]) are found by bilinear calibration. The relaxation time ([Formula: see text]), dielectric strength ([Formula: see text]) and the excess permittivity ([Formula: see text]) are found. The thermodynamic parameters such as enthalpy ([Formula: see text]), entropy ([Formula: see text]) and Gibb’s free energy ([Formula: see text]) are evolved. The significant changes in dielectric parameters are due to the intramolecular and intermolecular interactions in response to the applied frequency. The permittivity spectra of stearic acid–alcohol in the frequency range of 10[Formula: see text]MHz to 30[Formula: see text]GHz have been measured using picoseconds Time Domain Reflectometry (TDR). The dielectric parameters ([Formula: see text], [Formula: see text], [Formula: see text]) are found by bilinear calibration method. Influence of temperature in intermolecular interaction and the relaxation process are also studied. The FT-IR spectral analysis reveals that the conformation of functional groups and formation for hydrogen bonding are present in both binary and ternary mixtures of stearic acid.


2019 ◽  
Vol 16 (2) ◽  
pp. 580-584
Author(s):  
V. Ramalakshmi ◽  
U. Sankar ◽  
G. Parthipan

The dielectric relaxation study of amines and amide binary mixture has been determined over the frequency range of 10 MHZ to 20 GHZ, at 30 °C using time domain reflectometry (TDR) method for 11 concentrations of the system. The present work reveals molecular interaction between amines and amide. The static dielectric constant (ɛ), dielectric constant at high frequency (ɛ∞), relaxation time (τ), Effective Kirkwood correlation factors (geff) and Kirkwood correlation factors (gf) are computed by using Debye model. Formation of multimers in the mixture is identified by excess parameters and corresponding results are interpreted.


2018 ◽  
Author(s):  
Daechul Choi ◽  
Yoonseong Kim ◽  
Jongyun Kim ◽  
Han Kim

Abstract In this paper, we demonstrate cases for actual short and open failures in FCB (Flip Chip Bonding) substrates by using novel non-destructive techniques, known as SSM (Scanning Super-conducting Quantum Interference Device Microscopy) and Terahertz TDR (Time Domain Reflectometry) which is able to pinpoint failure locations. In addition, the defect location and accuracy is verified by a NIR (Near Infra-red) imaging system which is also one of the commonly used non-destructive failure analysis tools, and good agreement was made.


Author(s):  
Kendall Scott Wills ◽  
Omar Diaz de Leon ◽  
Kartik Ramanujachar ◽  
Charles P. Todd

Abstract In the current generations of devices the die and its package are closely integrated to achieve desired performance and form factor. As a result, localization of continuity failures to either the die or the package is a challenging step in failure analysis of such devices. Time Domain Reflectometry [1] (TDR) is used to localize continuity failures. However the accuracy of measurement with TDR is inadequate for effective localization of the failsite. Additionally, this technique does not provide direct 3-Dimenstional information about the location of the defect. Super-conducting Quantum Interference Device (SQUID) Microscope is useful in localizing shorts in packages [2]. SQUID microscope can localize defects to within 5um in the X and Y directions and 35um in the Z direction. This accuracy is valuable in precise localization of the failsite within the die, package or the interfacial region in flipchip assemblies.


Author(s):  
Bilal Abd-AlRahman ◽  
Corey Lewis ◽  
Todd Simons

Abstract A failure analysis application utilizing scanning acoustic microscopy (SAM) and time domain reflectometry (TDR) for failure analysis has been developed to isolate broken stitch bonds in thin shrink small outline package (TSSOP) devices. Open circuit failures have occurred in this package due to excessive bending of the leads during assembly. The tools and their specific application to this technique as well as the limitations of C-SAM, TDR and radiographic analyses are discussed. By coupling C-SAM and TDR, a failure analyst can confidently determine whether the cause of an open circuit in a TSSOP package is located at the stitch bond. The root cause of the failure was determined to be abnormal mechanical stress placed on the pins during the lead forming operation. While C-SAM and TDR had proven useful in the analysis of TSSOP packages, it can potentially be expanded to other wire-bonded packages.


Author(s):  
Teoh King Long ◽  
Ko Yin Fern

Abstract In time domain reflectometry (TDR), the main emphasis lies on the reflected waveform. Poor probing contact is one of the common problems in getting an accurate waveform. TDR probe normalization is essential before measuring any TDR waveforms. The advantages of normalization include removal of test setup errors in the original test pulse and the establishment of a measurement reference plane. This article presents two case histories. The first case is about a Plastic Ball Grid Array package consisting of 352 solder balls where the open failure mode was encountered at various terminals after reliability assessment. In the second, a three-digit display LED suspected of an electrical short failure was analyzed using TDR as a fault isolation tool. TDR has been successfully used to perform non-destructive fault isolation in assisting the routine failure analysis of open and short failure. It is shown to be accurate and reduces the time needed to identify fault locations.


Author(s):  
Lihong Cao ◽  
Manasa Venkata ◽  
Meng Yeow Tay ◽  
Wen Qiu ◽  
J. Alton ◽  
...  

Abstract Electro-optical terahertz pulse reflectometry (EOTPR) was introduced last year to isolate faults in advanced IC packages. The EOTPR system provides 10μm accuracy that can be used to non-destructively localize a package-level failure. In this paper, an EOTPR system is used for non-destructive fault isolation and identification for both 2D and 2.5D with TSV structure of flip-chip packages. The experimental results demonstrate higher accuracy of the EOTPR system in determining the distance to defect compared to the traditional time-domain reflectometry (TDR) systems.


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