Evaluation of Alternative Preparation Methods for Failure Analysis at Modern Chip and Package Technologies

2001 ◽  
Author(s):  
A. Dübotzky ◽  
B. Krüger
Keyword(s):  
Laser Ablation ◽  
Laser Pulse ◽  
Failure Analysis ◽  
Pulse Energy ◽  
Repetition Rate ◽  
Pulse Repetition Rate ◽  
Laser Pulse Energy ◽  
Preparation Methods ◽  
Silicon Thickness ◽  
Gold Wires

Abstract We evaluated laser ablation and sandblasting as preparation methods for package related failures and for backside analysis of ICs. With laser ablation we uncovered gold wedges on an internal board of a PLFBGA package without damage of the gold wires and the board metallization. This was possible by optimization of the laser pulse energy and the pulse repetition rate and by limitation of the ablation area. Sandblasting showed to be a gentle way for backside thinning down to 60 μm silicon thickness. For a surface smoothness sufficient for IR imaging a subsequent planarization treatment is necessary.

scholarly journals Surface characterization of laser-induced molten area in micro-grooving of silicon by ultraviolet (UV) laser

2021 ◽  
Vol 2051 (1) ◽  
pp. 012003
Author(s):  
N S A Raman ◽  
I H W Nordin ◽  
M S A Majid ◽  
Z M Razlan ◽  
S S C Abdullah
Keyword(s):  
Laser Pulse ◽  
Pulse Energy ◽  
Repetition Rate ◽  
Pulse Repetition Rate ◽  
Laser Pulse Energy ◽  
Scanning Speed ◽  
Pulse Repetition ◽  
Irradiation Condition ◽  
Uv Laser ◽  
High Pulse

Abstract The objective of this research is to understand the fundamental mechanisms that govern the formation of laser-induced molten area during the micro-grooved fabrication on silicon material. In this research work, micro grooves were fabricated on silicon wafer by using ultraviolet (UV) laser of 248nm wavelength. Influence of lasing parameters such as pulse duration, laser pulse energy and scanning speed on the surface of micro-grooved was characterized. It is found that, the width of the micro grooves become wider with increasing laser pulse energy when ultraviolet laser was irradiated on silicon material. On the other hand, heat affected zone (HAZ) can be found at the surface of micro groove line at high pulse energy, high pulse repetition rate and lower scanning speed irradiation condition. This is considered due to the excessive heat input of the laser irradiation condition. It is concluded that proper selection of laser processing parameters of pulse energy, E, pulse repetition rate, R p , and scanning speed is necessary to achieve high quality micro-grooves.

scholarly journals Effect of Laser Pulse Energy on the Formation of Alumina Nanoparticles Synthesized by Laser Ablation in Water

2012 ◽  
Vol 32 ◽  
pp. 1107-1112 ◽  
Author(s):  
V. Piriyawong ◽  
V. Thongpool ◽  
P. Asanithi ◽  
P. Limsuwan
Keyword(s):  
Laser Ablation ◽  
Laser Pulse ◽  
Pulse Energy ◽  
Laser Pulse Energy ◽  
Alumina Nanoparticles

scholarly journals Effect of Laser Energy and Repetition Rate on Holmium Plasma Emission

2020 ◽  
Vol 18 (44) ◽  
pp. 98-108
Author(s):  
Nipras Nazeh Mahmoad ◽  
Mahmoad Shakir Mahmoad
Keyword(s):  
Laser Pulse ◽  
Pulse Energy ◽  
Repetition Rate ◽  
Laser Pulse Energy ◽  
Laser Energy ◽  
Emission Spectra ◽  
Maximum Intensity ◽  
Plasma Emission ◽  
Line Intensities ◽  
Pulse Energies

The holmium plasma induced by a 1064-nmQ-switched Nd:YAG laser in air was investigated. This work was done theoretically and experimentally.  Cowan code was used to get the emission spectra for different transition of the holmium target. In the experimental work, the evolution of the plasma was studied by acquiring spectral images at different laser pulse energies (600,650,700, 750, and 800 mJ). The repetition rates of (1Hz and 10Hz) in the UV region (200-400 nm). The results indicate that, the emission line intensities increase with increasing of the laser pulse energy and repetition rate. The strongest emission spectra appeared when the laser pulse energy is 800mJ and 10 Hz repetition rate at λ= 345.64nm, with the maximum intensity of 77000 counts.

Surface Morphology of Silicon Induced by Laser Ablation in Flowing Water

2016 ◽  
Vol 861 ◽  
pp. 115-120 ◽  
Author(s):  
Wisan Charee ◽  
Viboon Tangwarodomnukun
Keyword(s):  
Surface Roughness ◽  
Laser Ablation ◽  
Laser Pulse ◽  
Flow Rate ◽  
Pulse Energy ◽  
Laser Pulse Energy ◽  
Water Flow Rate ◽  
Traverse Speed ◽  
Flowing Water ◽  
Cut Surface

Underwater laser machining process has a high potential over the typical laser ablation to remove materials with less thermal damage occurring along the cut. However, the formations of vapor bubble and cut debris in water can substantially disturb the incident laser beam, thereby reducing the ablation performance. Instead of performing the ablation in still water, the flowing water technique was applied to flush away the cut debris and bubble generated. In this study, the effects of laser pulse energy, traverse speed and water flow rate on the cut surface roughness and heat-affected zone in the laser grooving of silicon were experimentally investigated and analyzed. The findings revealed that the cut surface roughness decreased with the increases in laser pulse energy and laser traverse speed. Though a higher water flow rate resulted in a rougher cut surface, the heat-affected zone can be minimized when the increased flow rate was applied.

scholarly journals Adaptive Nonlinear Phase Compensation in a Femtosecond Hybrid Laser with Varying Pulse Repetition Rate

Photonics ◽  
2021 ◽  
Vol 8 (9) ◽  
pp. 387
Author(s):  
Luka Černe ◽  
Jaka Petelin ◽  
Rok Petkovšek
Keyword(s):  
Solid State ◽  
Laser Pulse ◽  
Pulse Duration ◽  
Pulse Energy ◽  
Repetition Rate ◽  
Pulse Repetition Rate ◽  
Pulse Repetition ◽  
Strehl Ratio ◽  
Pulse Parameters ◽  
Nonlinear Phase

In this manuscript, an implementation of a tunable nonlinear phase compensation method is demonstrated on a typical femtosecond hybrid laser consisting of a fiber pre-amplifier and an additional solid-state amplifier. This enables one to achieve constant laser pulse parameters over a wide range of pulse repetition rates in such a laser. As the gain in the solid-state amplifier is inversely proportional to the input power, the shortfall in the solid-state gain at higher repetition rates must be compensated for with fiber pre-amplifier to ensure constant pulse energy. This increases the accumulated nonlinear phase and consequently alters the laser pulse parameters such as pulse duration and Strehl ratio. To overcome this issue, the nonlinear phase must be compensated for, and what is more it should be compensated for to a different extent at different pulse repetition rates. This is achieved with a tunable CFBG, used also as a pulse stretcher. Using this concept, we demonstrate that constant laser pulse parameters such as pulse energy, pulse duration and Strehl ratio can be achieved in a hybrid laser regardless of the pulse repetition rate.

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