A New Technique to Generate Conductive Paths in Dielectric Materials

1993 ◽  
Vol 323 ◽  
Author(s):  
M. J. Desilva ◽  
A. J. Pedraza ◽  
D. H. Lowndes ◽  
M. J. Godbole
Keyword(s):  
Bond Strength ◽  
Laser Irradiation ◽  
Electroless Deposition ◽  
Laser Pulses ◽  
Dielectric Materials ◽  
Dielectric Surface ◽  
Uv Laser ◽  
Long Time ◽  
A New Technique ◽  
Pull Tests

AbstractWe have developed a new two-step process to generate a metallic pattern on dielectric materials. This method employs ultraviolet (uv) laser irradiation followed by electroless deposition. A few laser pulses are required to generate the pattern. After immersion in an electroless bath, the metal film is deposited only on the uv exposed area. Results of the application of this method to aluminum nitride and alumina are presented. The laser irradiation step is very fast, and the electroless deposition is simplified because it does not require any special seeding to promote activation, i.e. laser irradiation activates the dielectric surface for electroless deposition. In addition, the laser-induced activation of the insulator is maintained for a very long time allowing electroless deposition to be performed many months after irradiation. Patterns in the tens of microns can be produced on laser-exposed substrates. Pull tests have been performed to determine the bond strength. We have found that the bond strength can be further increased by annealing.

scholarly journals UV Laser Decay of Oxygen-Deficient Centers in Silica Glasses

1992 ◽  
Vol 12 (3-4) ◽  
pp. 211-222 ◽  
Author(s):  
V. N. Bagratashvili ◽  
S. I. Tsypina ◽  
S. S. Alimpiev ◽  
Ya. O. Simanovski ◽  
A. M. Prokhorov ◽  
...  
Keyword(s):  
Scale Up ◽  
Laser Pulses ◽  
Uv Laser ◽  
Recombination Luminescence ◽  
Simultaneous Formation ◽  
Temporal Behaviour ◽  
Silica Glasses ◽  
Dose Number ◽  
Long Time ◽  
Shallow Traps

Oxygen-deficient centers decay with simultaneous formation of color centers in IR and UV grade silica glasses under KrF laser irradiation was studied. The nonexponential dependence of the ODC photodecay in silica glass on the UV irradiation dose (number of laser pulses) was observed. Postpulse long-time temporal behaviour of recombination luminescence and laser induced photoconductivity was analyzed for the two types of glasses in time scale up to 0.5 ms. Long time fluorescence tail is attributed to migration of electrons through the shallow traps before recombination and recovery of ODC. The models of postpulse recombination which can explain the observed nonexponential behaviour of ODC decay (geminal and homogeneous) are discussed. The principle part of impurities caused electron traps in the postpulse ODC recombination is shown.

Crystallization of Amorphous Titanium Oxide Thin Films by Pulsed UV-Laser Irradiation

1995 ◽  
Vol 397 ◽  
Author(s):  
Yo Ichikawa ◽  
Hideaki Ada Chi ◽  
Kentaro Setsune ◽  
Syun-Ichiro Kawashima ◽  
Koichi Kugimiya
Keyword(s):  
Crystal Structure ◽  
Thin Films ◽  
Laser Irradiation ◽  
Optical Transmission ◽  
Laser Pulses ◽  
Uv Laser ◽  
Before And After ◽  
Krf Excimer Laser ◽  
Quartz Substrates ◽  
Local Crystal Structure

ABSTRACTEffects of ultraviolet (UV) laser irradiation on the local crystal structure have been investigated for amorphous Ti-O thin films sputtered on ST-cut quartz substrates. The irradiation was conducted with a pulsed KrF excimer laser of 248nm in wavelength. There were few changes in the optical transmission spectra of the films before and after the irradiation. The crystal structure of the films was characterized by electron diffraction, XPS and EXAFS analyses. The results obtained from these analyses suggest the films gradually crystallize to a TiO2 crystal with the rutile type structure by the increasing of the laser pulses.

Microstructural changes of Aluminum Nitride after laser irradiation and electroless copper deposition

1994 ◽  
Vol 52 ◽  
pp. 636-637
Author(s):  
S. Cao ◽  
A. J. Pedraza ◽  
L. F. Allard
Keyword(s):  
Aluminum Nitride ◽  
Laser Irradiation ◽  
Electroless Deposition ◽  
Thermal Evaporation ◽  
Surface Region ◽  
Near Surface ◽  
Laser Patterning ◽  
Electroless Copper ◽  
Excimer Laser Irradiation ◽  
Laser Effect

Excimer-laser irradiation strongly modifies the near-surface region of aluminum nitride (AIN) substrates. The surface acquires a distinctive metallic appearance and the electrical resistivity of the near-surface region drastically decreases after laser irradiation. These results indicate that Al forms at the surface as a result of the decomposition of the Al (which has been confirmed by XPS). A computer model that incorporates two opposing phenomena, decomposition of the AIN that leaves a metallic Al film on the surface, and thermal evaporation of the Al, demonstrated that saturation of film thickness and, hence, of electrical resistance is reached when the rate of Al evaporation equals the rate of AIN decomposition. In an electroless copper bath, Cu is only deposited in laser-irradiated areas. This laser effect has been designated laser activation for electroless deposition. Laser activation eliminates the need of seeding for nucleating the initial layer of electroless Cu. Thus, AIN metallization can be achieved by laser patterning followed by electroless deposition.

Studies on the mechanism of printing film-coated tablets containing titanium dioxide in the film by using UV laser irradiation

2009 ◽  
Vol 00 (00) ◽  
pp. 090915102728058-8
Author(s):  
Yoshiteru Kato ◽  
Yasuhiko Nakashima ◽  
Naoki Shino ◽  
Koichi Sasaki ◽  
Akihiro Hosokawa ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Laser Irradiation ◽  
Uv Laser

scholarly journals Analytical Investigation on the Effect of Test Setup on Bond Strength

CivilEng ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 14-34
Author(s):  
Konstantinos Tsiotsias ◽  
Stavroula J. Pantazopoulou
Keyword(s):  
Bond Strength ◽  
Pullout Test ◽  
Analytical Investigation ◽  
Strength Increase ◽  
Confining Stress ◽  
Direct Tension ◽  
Bond Slip ◽  
Test Setup ◽  
Long Time

Experimental procedures used for the study of reinforcement to concrete bond have been hampered for a long time by inconsistencies and large differences in the obtained behavior, such as bond strength and mode of failure, depending on the specimen form and setup used in the test. Bond is controlled by the mechanics of the interface between reinforcement and concrete, and is sensitive to the influences of extraneous factors, several of which underlie, but are not accounted for, in conventional pullout test setups. To understand and illustrate the importance of specimen form and testing arrangement, a series of computational simulations are used in the present work on eight distinct variants of conventional bar pullout test setups that are used routinely in experimental literature for the characterization of bond-slip laws. The resulting bond strength increase generated by unaccounted confining stress fields that arise around the bar because of the boundary conditions of the test setup is used to classify the tests with respect to their relevance with the intended use of the results. Of the pullout setups examined, the direct tension pullout test produced the most conservative bond strength results, completely eliminating the contributions from eccentricity and passive confinement.

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