Detectable Resistance Increase of Open Defects in Assembled PCBs by Quiescent Currents through Embedded Diodes

2021 ◽  
Author(s):  
Yuya Okumoto ◽  
Hiroyuki Yotsuyanagi ◽  
Masaki Hashizume ◽  
Shyue-Kung Lu
Keyword(s):  
Resistance Increase ◽  
Open Defects

Open Localization in Micro LeadFrame Package Using Space Domain Reflectometry

2013 ◽  
Author(s):  
J. Gaudestad ◽  
V. Talanov ◽  
A. Orozco ◽  
M. Marchetti
Keyword(s):  
Magnetic Field ◽  
Radio Frequency ◽  
Standing Wave ◽  
High Resistance ◽  
Space Domain ◽  
The Past ◽  
Open Defects ◽  
Rf Electronics ◽  
Rf Signal ◽  
The Magnetic Field

Abstract In the past couple years, Space Domain Reflectometry (SDR) has become a mainstream method to locate open defects among the major semiconductor manufacturers. SDR injects a radio frequency (RF) signal into the open trace creating a standing wave with a node at the open location. The magnetic field generated by the standing wave is imaged with a SQUID sensor using RF electronics. In this paper, we show that SDR can be used to non-destructively locate high resistance failures in Micro LeadFrame Packages (MLP).

Fault Isolation of Open Defects Using Space Domain Reflectometry

2012 ◽  
Author(s):  
Mayue Xie ◽  
Zhiguo Qian ◽  
Mario Pacheco ◽  
Zhiyong Wang ◽  
Rajen Dias ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Fault Isolation ◽  
Nondestructive Technique ◽  
Space Domain ◽  
New Approach ◽  
Defect Localization ◽  
Open Faults ◽  
Open Defects ◽  
Application Optimization ◽  
Rf Magnetic Field

Abstract Recently, a new approach for isolation of open faults in integrated circuits (ICs) was developed. It is based on mapping the radio-frequency (RF) magnetic field produced by the defective part fed with RF probing current, giving the name to Space Domain Reflectometry (SDR). SDR is a non-contact and nondestructive technique to localize open defects in package substrates, interconnections and semiconductor devices. It provides 2D failure isolation capability with defect localization resolution down to 50 microns. It is also capable of scanning long traces in Si. This paper describes the principles of the SDR and its application for the localization of open and high resistance defects. It then discusses some analysis methods for application optimization, and gives examples of test samples as well as case studies from actual failures.

Sharper Labyrinth Seal Edges to Allow Greater Clearance Without Increased Leakage

1995 ◽  
Author(s):  
David L. Rhode ◽  
M. J. Guidry
Keyword(s):  
Numerical Study ◽  
Energy Generation ◽  
Labyrinth Seal ◽  
Leakage Rate ◽  
Turbulence Energy ◽  
Resistance Increase ◽  
Leakage Resistance ◽  
Edge Sharpness ◽  
Damage Susceptibility

Abstract A numerical study was undertaken to examine the effects of utilizing sharper edges for increasing the leakage resistance of advanced labyrinth seal configurations. Such an increase allows the designer to enlarge the extremely small knife clearance, providing a seal with less damage susceptibility at the same leakage rate. The maximum possible leakage resistance increase from changing three cavity edges to perfectly sharp ones was estimated from the present computations. In addition, previous measurements of the edge sharpness effect on the leakage through orifices are appropriately utilized to obtain a rough estimate of the resistance increase for generic seals. The latter allows consideration of a broader range of application. Further, turbulence energy generation contours reveal that only one particular cavity edge needs to be sharpened in order to obtain a significantly increased leakage resistance.

scholarly journals Ionic mechanisms of two types of on-center bipolar cells in the carp retina. I. The responses to central illumination.

1979 ◽  
Vol 73 (1) ◽  
pp. 73-90 ◽  
Author(s):  
T Saito ◽  
H Kondo ◽  
J I Toyoda
Keyword(s):  
Reversal Potential ◽  
Maximum Amplitude ◽  
Bipolar Cells ◽  
Light Spot ◽  
Membrane Properties ◽  
Resistance Increase ◽  
Membrane Conductances ◽  
Electric Interaction ◽  
Ionic Mechanisms ◽  
Resistance Decrease

Properties of the depolarizing response of on-center bipolar cells to a light spot stimulus were studied in the carp retina. On-center bipolar cells were classified into two types, cone-dominant and rod-dominant, according to their major input from cones and rods. Cone-dominant bipolar cells responded to spectral light with the maximum amplitude near 625 nm, suggesting major input from red cones. The response was accompanied by a resistance increase and showed a reversal potential at -63 +/- 21 mV when the membrane was hyperpolarized by current. The results suggest that the photoresponse of cone-dominant cells is due to a decrease of gK and/or gCl, membrane conductances to potassium and chloride, respectively. Rod-dominant bipolar cells responded to spectral light with the maximum amplitude near 525 nm under scotopic conditions and near 625 nm under photopic conditions, providing evidence that they receive input from rods and red cones. In the scoptopic condition their response was accompanied by a resistance decrease and showed a reversal potential at 29 +/- 13 mV, whereas in the photopic condition the response in most of them was accompanied by a resistance increase, at least in their part and showed a reversal at -53 +/- 11 mV. The results suggest that the photoresponse activated by rod input is due to an increase in gNa. In the mesopic condition rod-dominant cells showed complex electrical membrane properties as the result of electric interaction between the above two differnt ionic mechanisms activated by rod and cone inputs.

scholarly journals Investigation of the properties of composite materials based on epoxy resins with microsilica additives

2021 ◽  
Vol 318 (3) ◽  
pp. 63-70
Author(s):  
M.A. Serekpayeva ◽  
◽  
G.А. Kokayeva ◽  
R.K. Niyazbekova ◽  
S. Kardybai ◽  
...  
Keyword(s):  
Composite Materials ◽  
Epoxy Resin ◽  
Corrosion Protection ◽  
Epoxy Resins ◽  
Machine Maintenance ◽  
Resistance Increase ◽  
Dispersed Filler ◽  
Filler Particles

The outcomes of studying epoxy-based composite materials supplemented with microsilica are provided in the article. Microsilica was used as a filler. The samples were produced on the epoxy ED-20 basis supplemented with 2, 5 and 10 mas. % of microsilica. The structure and size of finely dispersed filler particles were defined. The obtained composites were tested for resistance to the effect of variable temperatures, corrosive, and abrasion. The study outcomes proved that samples supplemented with 2% of microsilica are more resistant to acid and alkali as well as to petrol than those ones supplemented with 25% of microsilica. Besides the amount of the filler from 2 to 10% doesn’t sufficiently affect the resistance to variable temperatures. When microsilica is added to epoxy resin, it causes scuff resistance increase. The conducted testing proved that the developed composite materials are resistant to the effect of variable temperatures, corrosive, and abrasion. This enables to use these materials as coatings and anti-corrosion protection during machine maintenance.

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