Discrimination of Surface Textures Using Fractal Methods

1994 ◽  
Vol 367 ◽  
Author(s):  
Jill P. Card ◽  
J. M. Hyde ◽  
T. Giversen
Keyword(s):  
Fractal Analysis ◽  
Copper Foil ◽  
Copper Surface ◽  
Electronic Packages ◽  
Confidence Limits ◽  
Lead Frame ◽  
Copper Surfaces ◽  
Surface Textures ◽  
Fractal Approach ◽  
Copper Lead

AbstractThis paper investigates the use of fractal metrics for discrimination of copper surface textures. Measurements of copper surfaces, using contacting profilometry, provided the raw data for the fractal analysis. The samples tested included copper foil samples and a copper lead frame, typical of those in use in plastic electronic packages. The fractal Hausdorf dimension and upper/lower ranges of fractal scale are analyzed by the coastline method and compared using Bonferroni multiple confidence limits. Metrics show significant differences between sample couplets, indicating significant precision in the fractal approach to adequately quantify surface texture qualities.

Rapid Spray Method for Improving Cu-Epoxy Interface Strength

2010 ◽  
Author(s):  
Robert C. Wetherhold ◽  
Elena Pisanova ◽  
Hani Alarifi
Keyword(s):  
Aqueous Solution ◽  
Copper Foil ◽  
Surface Coverage ◽  
Peel Strength ◽  
Copper Surface ◽  
Interface Strength ◽  
Range Effect ◽  
Trade Off ◽  
Copper Surfaces ◽  
Spray Method

A simple spray method using a plain orifice atomizer has been developed for depositing γ-aminopropyltriethoxysilane (APS) from solutions in water and in methanol onto copper surfaces. The peel strengths between copper foil and epoxy resin were measured with and without APS deposition. In all cases, a higher concentration of APS gives higher peel strength. APS applied from 1 wt% solution in methanol resulted in higher peel strength than when applied from a 1 wt% aqueous solution; the opposite was true with 0.2 wt% APS solutions, indicating a trade-off between deposited APS film thickness and surface coverage. APS was very effective when chemisorption occurred at the surface but much less effective when there was only physisorption. A study of the fracture surfaces showed that the failure is cohesive, inside the epoxy layer, and that the deposited APS on the copper surfaces had a long-range effect which was seen deep in the epoxy layer, well away from the copper surface.

scholarly journals The mechanism of catalytic decomposition

1925 ◽  
Vol 108 (746) ◽  
pp. 355-378 ◽  
Keyword(s):  
Copper Foil ◽  
Active Agent ◽  
Catalytic Decomposition ◽  
Hydrocarbon Chain ◽  
Copper Surface ◽  
Catalytic Action ◽  
Hydroxyl Group ◽  
Copper Surfaces ◽  
X Ray ◽  
Molecular Attraction

In recent years a large amount of evidence has accumulated showing that the range of molecular attraction is very small; hence the specific catalytic action of each substance must decrease very fast as the distance of the reacting molecules from the surface increases. The catalytic action must therefore be confined to the surface layer of adsorbed molecules alone. When alcoholic substances react at copper surfaces below 280° C., only the — CH 2 OH group is changed. The only molecules which react, therefore, are those which have the — CH 2 OH group in contact with the copper. The behaviour of cetyl alcohol on water, and on glass and steel, shows that the hydroxyl group is the active agent in orientating the film structure.It is known also that alcohol will displace hydrocarbons from copper foil. The polar hydroxyl group is attracted to the copper surface more strongly than is the hydrocarbon chain. The evidence, therefore, shows that not only are the molecules that react adsorbed with the hydroxyl group in contact with the surface, but that the whole layer in contact with the catalyst is orientated in this manner. It may be that the molecules in the successive layers are also arranged similarly, but the evidence is scanty. In the case of the fatty acids, X-ray analysis gives confirmation of this arrangement

Heterogeneity of Cerebral Blood Flow: a Fractal Approach

2000 ◽  
Vol 39 (02) ◽  
pp. 37-42 ◽  
Author(s):  
P. Hartikainen ◽  
J. T. Kuikka
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Fractal Dimension ◽  
Frontal Lobe ◽  
Fractal Analysis ◽  
Relative Dispersion ◽  
Emission Computed Tomography ◽  
Brain Blood Flow ◽  
Healthy Controls ◽  
Fractal Approach

Summary Aim: We demonstrate the heterogeneity of regional cerebral blood flow using a fractal approach and singlephoton emission computed tomography (SPECT). Method: Tc-99m-labelled ethylcysteine dimer was injected intravenously in 10 healthy controls and in 10 patients with dementia of frontal lobe type. The head was imaged with a gamma camera and transaxial, sagittal and coronal slices were reconstructed. Two hundred fifty-six symmetrical regions of interest (ROIs) were drawn onto each hemisphere of functioning brain matter. Fractal analysis was used to examine the spatial heterogeneity of blood flow as a function of the number of ROIs. Results: Relative dispersion (= coefficient of variation of the regional flows) was fractal-like in healthy subjects and could be characterized by a fractal dimension of 1.17 ± 0.05 (mean ± SD) for the left hemisphere and 1.15 ± 0.04 for the right hemisphere, respectively. The fractal dimension of 1.0 reflects completely homogeneous blood flow and 1.5 indicates a random blood flow distribution. Patients with dementia of frontal lobe type had a significantly lower fractal dimension of 1.04 ± 0.03 than in healthy controls. Conclusion: Within the limits of spatial resolution of SPECT, the heterogeneity of brain blood flow is well characterized by a fractal dimension. Fractal analysis may help brain scientists to assess age-, sex- and laterality-related anatomic and physiological changes of brain blood flow and possibly to improve precision of diagnostic information available for patient care.

Backside Mechanical Preparation Methodology for Effective Failure Analysis on Small and Non-Exposed Die Paddle Package

2018 ◽  
Author(s):  
Ong Pei Hoon ◽  
Ng Kiong Kay ◽  
Gwee Hoon Yen
Keyword(s):  
Failure Analysis ◽  
Chemical Etching ◽  
Chemical Resistance ◽  
Etching Time ◽  
Lead Frame ◽  
Front Side ◽  
Electrical Measurements ◽  
Mechanical Preparation ◽  
Die Surface ◽  
Copper Lead

Abstract Chemical etching is commonly used in exposing the die surface from die front-side and die backside because of its quick etching time, burr-free and stress-free. However, this technique is risky when performing copper lead frame etching during backside preparation on small and non-exposed die paddle package. The drawback of this technique is that the copper leads will be over etched by 65% Acid Nitric Fuming even though the device’s leads are protected by chemical resistance tape. Consequently, the device is not able to proceed to any other further electrical measurements. Therefore, we introduced mechanical preparation as an alternative solution to replace the existing procedure. With the new method, we are able to ensure the copper leads are intact for the electrical measurements to improve the effectiveness and accuracy of physical failure analysis.

Cu-Direct Laser Drilling of Blind Via-Hole in Multi-Layer PWBs: Influence of Surface Treatment on Drilled Hole Quality

2009 ◽  
Author(s):  
Toshiki Hirogaki ◽  
Eiichi Aoyama ◽  
Keiji Ogawa ◽  
Tsukasa Ayuzawa
Keyword(s):  
Surface Treatment ◽  
Co2 Laser ◽  
Copper Foil ◽  
Laser Energy ◽  
Copper Surface ◽  
Laser Drilling ◽  
Hole Quality ◽  
Direct Laser ◽  
Overhang Length ◽  
Direct Drilling

This report describes the quality assessment of Blind Via Holes (BVHs) of Printed Wiring Boards (PWBs) drilled by a CO2 laser using Cu-direct drilling. In the Cu-direct drilling method, the copper foil and the build-up layer are melted at the same time, and the surface is treated to increase the laser energy absorbed by the copper foil since an untreated copper surface reflects most of the 10.6-μm-wavelength CO2 laser beam. However, there are few reports dealing with Cu-direct laser drilling of PWBs. In addition, when copper and resin with different processing thresholds are drilled at the same time, occurrences of a defect called overhang have been observed. So, in this report, first we propose a new method using thermography to measure the absorptance of a PWB surface for a CO2 laser. Moreover, we investigate how surface treatment of the outer copper foil influences the quality of a laser-drilled hole. Then, we observe the circumference of a point irradiated with the CO2 laser and explain how melting processes are different from surface treatment. Finally, based on the research we establish a method in order to cut down the overhang length as a parameter of drilled-hole quality. We also show that a high absorptance improves BVH quality.

scholarly journals Usage of Sims and Auger Test Methods in the Production of Multilayer Printed Circuit Boards

1984 ◽  
Vol 11 (3) ◽  
pp. 225-229
Author(s):  
E. Toth ◽  
P. Banlaki ◽  
I. Hajdu ◽  
J. Pinkola
Keyword(s):  
Copper Foil ◽  
Printed Circuit Boards ◽  
Copper Surface ◽  
Test Methods ◽  
Main Constituent ◽  
Circuit Boards ◽  
Adhesion Properties ◽  
Printed Circuit ◽  
Quality And Reliability ◽  
Type Electrolyte

The quality and reliability of multilayer boards are determined by the adhesion strength between the copper sheets and the epoxy-glass laminates. The adhesion properties of copper foil may be improved by mechanical or chemical roughening. The most efficient method is, however, to oxidize the copper surface.Oxidized copper layers have been tested by thermogravimetry. Subsequently the oxide layers have been tested by Auger and SIMS techniques. The results showed that the main constituent of the oxide layer produced in a sodium hypochlorite type electrolyte is Cu20.

scholarly journals Analisis Dimensi Fraktal Kejadian Gempa Dl Laut Banda Indonesia

2016 ◽  
Vol 19 (2) ◽  
pp. 108
Author(s):  
Sugeng Widada
Keyword(s):  
Fractal Dimension ◽  
Fractal Analysis ◽  
Fractal Approach ◽  
Study Support ◽  
Tectonic System

The Banda Sea region is an active earthquakes area which indicated by mean monthly incident of quakes more than 220. The condition is caused the area being located in the triple jucntion. Earthquakes system in this region which occur during September 2015 up to October 2016 is analyzed by fractal approach to investigate the subduction system.Earthquakes system is chaotic, so can be quantified using fractal concept. Quantify result of Banda Sea earthquakes system using Aki method is fractal dimension 2.08. It indicates that the slab was fractured by some fault in form an angle or upright possition with the subduction strike. Such a thing also be proven by the fact that the length zone of slab moved during each earthquake is not same, the variation is about 6 – 1,056 m. Based on the fractal analysis, also be identified that about 6.25 magnitute six earthquakes are expected each year. The result of study support the previous studies which propose that the tectonic system in Banda Sea region is very complex. Keywards:  Earthuakes system, fractal, Banda Sea Kawasan Laut Banda merupakan daerah aktif gempa yang ditunjukan dengan kejadian gempa rata-rata bulanan Iebih dan 220. Keadaan ini dapat dimengerti mengingat kawasan tersebut merupakan pertemuan tiga buah lempeng yang bergerak. Pola kegempaan di daerah tesebut yang tejadi pada September 2015 hingga Oktober 2016 dicoba dianalisa menggunakan pendekatan fraktal untuk mengetahui pola subduksi di daerah tersebut. Pola kegempaan merupakan suatu kejadian yang chaos, sehingga dapat dilakukan kuantisasi berdasarkan konsep fraktal. Hasil kuantisasi pola gempa Laut Banda meggunakan metode Aki diperoleh dimensi fraktal 2,08. Hal ini menunjukan bahwa slab yang menunjam dan bergerak sehingga menimbulkan gempa terbagi dalarn beberapa bagian melalui suatu sesar yang menyududut / tegak lurus jurus subduksi. Keadaan ini dikuatkan oleh hasil perhitungan panjang daerah yang bergerak untuk setiap kejadian gempa tidak sama, yaitu bervariasi dari 6 – 1.056 m. Berdasarkan analisa fraktal tersebut juga diketahui bahwa gempa dengan magnitudo 6,25 akan terjadi 6 kali dalam satu tahun. Hasil penelitian ini mendukung hasil penelitian terdahulu yang menyatakan bahwa tatanan tektonik di daerah Laut Banda sangat kompleks. Kata Kunci: Pole gempa, fraktal, Laut Banda

Copper lead frame: an ultimate solution to the reliability of BLP package

2000 ◽  
Vol 23 (1) ◽  
pp. 32-38 ◽  
Author(s):  
Kwang-Seong Choi ◽  
Teck-Gyu Kang ◽  
Ik-Seong Park ◽  
Jong-Hyun Lee ◽  
Ki-Bon Cha
Keyword(s):  
Lead Frame ◽  
Copper Lead
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