WLCSP Laminate Removal Using NIR Laser

2018 ◽  
Author(s):  
Chun Haur Khoo
Keyword(s):  
Near Infrared ◽  
Laser Energy ◽  
Photon Emission ◽  
Mechanical Damage ◽  
Consumer Products ◽  
Fault Isolation ◽  
Wafer Level ◽  
Isolation Technique ◽  
Laminate Layer ◽  
Nir Laser

Abstract Driven by the cost reduction and miniaturization, Wafer Level Chip Scale Packaging (WLCSP) has experienced significant growth mainly driven by mobile consumer products. Depending on the customers or manufacturing needs, the bare silicon backside of the WLCSP may be covered with a backside laminate layer. In the failure analysis lab, in order to perform the die level backside fault isolation technique using Photon Emission Microscope (PEM) or Laser Signal Injection Microscope (LSIM), the backside laminate layer needs to be removed. Most of the time, this is done using the mechanical polishing method. This paper outlines the backside laminate removal method of WLCSP using a near infrared (NIR) laser that produces laser energy in the 1,064 nm range. This method significantly reduces the sample preparation time and also reduces the risk of mechanical damage as there is no application of mechanical force. This is an effective method for WLCSP mounted on a PCB board.

Monte Carlo Simulation of Enhanced Laser Absorption in Tumors With Gold Nanorod Injection

2011 ◽  
Author(s):  
Yonghui Chen ◽  
Ronghui Ma ◽  
Liang Zhu
Keyword(s):  
Gold Nanorods ◽  
Targeted Delivery ◽  
Near Infrared ◽  
Laser Energy ◽  
Gold Nanoshells ◽  
Surrounding Tissue ◽  
Laser Absorption ◽  
The Past ◽  
Tumor Region ◽  
Nir Laser

The employment of gold nanoshells or nanorods in photothermal emerges as a promising technology in treatment of cancers in the past several years [1–4]. Gold nanoshells consist of a solid dielectric core nanoparticle (∼100 nm) coated by a thin gold shell (∼10 nm). Gold nanorods are usually small with a size of ∼10 nm and an aspect ratio of approximately four. By varying the size ratio, the nanostructures can be tuned to have strong absorption and scattering to a specific near infrared (NIR) laser at ∼800 nm. The enhancement in laser energy absorption is several orders of magnitude compared to some traditional dyes [1]. The laser energy absorbed in an area congregating by the nanostructures is transferred to the surrounding tissue by heat conduction. The nanostructures in tumors not only enables targeted delivery of laser energy, but also maximally concentrates a majority of the laser energy to the tumor region.

scholarly journals New techniques for laser beam atmospheric extinction measurements from manned and unmanned aerospace vehicles

2013 ◽  
Vol 3 (1) ◽  
Author(s):  
Roberto Sabatini ◽  
Mark Richardson
Keyword(s):  
Laser Beam ◽  
Near Infrared ◽  
Laser Energy ◽  
Laser System ◽  
Direct Determination ◽  
Atmospheric Conditions ◽  
Atmospheric Extinction ◽  
Laser Systems ◽  
Non Linear Propagation ◽  
Nir Laser

AbstractNovel techniques for laser beam atmospheric extinction measurements, suitable for several air and space platform applications, are presented in this paper. Extinction measurements are essential to support the engineering development and the operational employment of a variety of aerospace electro-optical sensor systems, allowing calculation of the range performance attainable with such systems in current and likely future applications. Such applications include ranging, weaponry, Earth remote sensing and possible planetary exploration missions performed by satellites and unmanned flight vehicles. Unlike traditional LIDAR methods, the proposed techniques are based on measurements of the laser energy (intensity and spatial distribution) incident on target surfaces of known geometric and reflective characteristics, by means of infrared detectors and/or infrared cameras calibrated for radiance. Various laser sources can be employed with wavelengths from the visible to the far infrared portions of the spectrum, allowing for data correlation and extended sensitivity. Errors affecting measurements performed using the proposed methods are discussed in the paper and algorithms are proposed that allow a direct determination of the atmospheric transmittance and spatial characteristics of the laser spot. These algorithms take into account a variety of linear and non-linear propagation effects. Finally, results are presented relative to some experimental activities performed to validate the proposed techniques. Particularly, data are presented relative to both ground and flight trials performed with laser systems operating in the near infrared (NIR) at λ= 1064 nm and λ= 1550 nm. This includes ground tests performed with 10 Hz and 20 KHz PRF NIR laser systems in a large variety of atmospheric conditions, and flight trials performed with a 10 Hz airborne NIR laser system installed on a TORNADO aircraft, flying up to altitudes of 22,000 ft.

Advanced T-LSIM System Detections using Amplified External Isolated Source-Sense Unit

2018 ◽  
Author(s):  
Zhi Jie Lau ◽  
Chris Philips
Keyword(s):  
Fault Isolation ◽  
Isolation Technique ◽  
Laser Signal ◽  
Signal Injection ◽  
Sense Unit ◽  
Types Of Faults

Abstract Thermal-Laser Signal Injection Microscopy (T-LSIM) is a widely used fault isolation technique. Although there are several T-LSIM systems on the market, each is limited in terms of the voltage and current it can produce. In this paper, the authors explain how they incorporated an Amplified External Isolated Source-Sense (AxISS) unit into their T-LSIM platform, increasing its current sourcing capability and voltage biasing range. They also provide examples highlighting the types of faults and failures that the modified system can detect.

Fault Isolation of MOL and FEOL Buried Defects Using Conductive Atomic Force Microscopy as a Complement to Passive Voltage Contrast Imaging

2017 ◽  
Author(s):  
Lucile C. Teague Sheridan ◽  
Linda Conohan ◽  
Chong Khiam Oh
Keyword(s):  
Atomic Force Microscopy ◽  
Cmos Technology ◽  
Fault Isolation ◽  
Contrast Imaging ◽  
Conductive Atomic Force Microscopy ◽  
Isolation Technique ◽  
Conductive Afm ◽  
Force Microscopy ◽  
Atomic Force ◽  
Voltage Contrast

Abstract Atomic force microscopy (AFM) methods have provided a wealth of knowledge into the topographic, electrical, mechanical, magnetic, and electrochemical properties of surfaces and materials at the micro- and nanoscale over the last several decades. More specifically, the application of conductive AFM (CAFM) techniques for failure analysis can provide a simultaneous view of the conductivity and topographic properties of the patterned features. As CMOS technology progresses to smaller and smaller devices, the benefits of CAFM techniques have become apparent [1-3]. Herein, we review several cases in which CAFM has been utilized as a fault-isolation technique to detect middle of line (MOL) and front end of line (FEOL) buried defects in 20nm technologies and beyond.

Case Study in Fault Isolation of a Metal Short for Yield Enhancement

2010 ◽  
Author(s):  
Sarven Ipek ◽  
David Grosjean
Keyword(s):  
Failure Analysis ◽  
Failure Mechanism ◽  
Photon Emission ◽  
Fault Isolation ◽  
Yield Enhancement ◽  
Analysis Technique ◽  
Laser Signal ◽  
Signal Injection ◽  
Microscopy Techniques

Abstract The application of an individual failure analysis technique rarely provides the failure mechanism. More typically, the results of numerous techniques need to be combined and considered to locate and verify the correct failure mechanism. This paper describes a particular case in which different microscopy techniques (photon emission, laser signal injection, and current imaging) gave clues to the problem, which then needed to be combined with manual probing and a thorough understanding of the circuit to locate the defect. By combining probing of that circuit block with the mapping and emission results, the authors were able to understand the photon emission spots and the laser signal injection microscopy (LSIM) signatures to be effects of the defect. It also helped them narrow down the search for the defect so that LSIM on a small part of the circuit could lead to the actual defect.

3D IC/Stacked Device Fault Isolation Using 3D Magnetic Field Imaging

2014 ◽  
Author(s):  
A. Orozco ◽  
N.E. Gagliolo ◽  
C. Rowlett ◽  
E. Wong ◽  
A. Moghe ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Fault Isolation ◽  
Wafer Level ◽  
Wafer Level Packaging ◽  
Current Location ◽  
Geometrical Information ◽  
Magnetic Field Imaging ◽  
Silicon Vias ◽  
Non Destructive ◽  
Field Imaging

Abstract The need to increase transistor packing density beyond Moore's Law and the need for expanding functionality, realestate management and faster connections has pushed the industry to develop complex 3D package technology which includes System-in-Package (SiP), wafer-level packaging, through-silicon-vias (TSV), stacked-die and flex packages. These stacks of microchips, metal layers and transistors have caused major challenges for existing Fault Isolation (FI) techniques and require novel non-destructive, true 3D Failure Localization techniques. We describe in this paper innovations in Magnetic Field Imaging for FI that allow current 3D mapping and extraction of geometrical information about current location for non-destructive fault isolation at every chip level in a 3D stack.

Sample Preparation Challenges In WLCSP Epoxy Underfill Coating Removal

2012 ◽  
Author(s):  
Jason H. Lagar ◽  
Rudolf A. Sia
Keyword(s):  
Sample Preparation ◽  
Failure Analysis ◽  
Vital Role ◽  
Fault Isolation ◽  
Wafer Level ◽  
Chip Scale Package ◽  
Coating Removal ◽  
Customer Returns ◽  
Preparation Techniques ◽  
Mechanical Defect

Abstract Most Wafer Level Chip Scale Package (WLCSP) units returned by customers for failure analysis are mounted on PCB modules with an epoxy underfill coating. The biggest challenge in failure analysis is the sample preparation to remove the WLCSP device from the PCB without inducing any mechanical defect. This includes the removal of the underfill material to enable further electrical verification and fault isolation analysis. This paper discusses the evaluations conducted in establishing the WLCSP demounting process and removal of the epoxy underfill coating. Combinations of different sample preparation techniques and physical failure analysis steps were evaluated. The established process enabled the electrical verification, fault isolation and further destructive analysis of WLCSP customer returns mounted on PCB and with an epoxy underfill coating material. This paper will also showcase some actual full failure analysis of WLCSP customer returns where the established process played a vital role in finding the failure mechanism.

A Novel OBIRCH Fault Isolation Method to Locate the Leakage Failure Point

2008 ◽  
Author(s):  
Chi-Lin Huang ◽  
Yu Hsiang Shu
Keyword(s):  
Semiconductor Device ◽  
Fault Isolation ◽  
Resistance Change ◽  
Cross Sectional ◽  
Isolation Technique ◽  
Isolation Techniques ◽  
Atomic Force ◽  
Analysis Experiment ◽  
Failure Point ◽  
Leakage Failure

Abstract Conventional isolation techniques, such as Optical Beam Induced Resistance Change (OBIRCH) or photoemission microscopy (PEM) frequently fail to locate failure points when only applied to power pin of the semiconductor device. In this paper, a novel OBIRCH failure isolation technique is utilized to detect leakage failures. Different test conditions are presented to identify the differences in current when all input pins are pulled high in an OBIRCH system. In order to verify a failure point, it is necessary to perform electrical analysis of the suspected failure point in the failing sample. In general, Conductive Atomic Force Microscope (C-AFM) and a Nano-Prober is sufficient to provide the electrical data required for failure analysis. Experiment results, however, prove that this novel OBIRCH failure isolation technique is effective in locating the failure point, especially for leakage failures. The failure mechanism is illustrated using cross-sectional TEM.

Photon Emission Spectral Signatures of AlGaN/GaN HEMT for Functional and Reliability Analysis

2008 ◽  
Author(s):  
Arkadiusz Glowacki ◽  
Christian Boit ◽  
Richard Lossy ◽  
Joachim Würfl
Keyword(s):  
Reliability Analysis ◽  
Gate Voltage ◽  
Near Infrared ◽  
Photon Emission ◽  
Electrical Characterization ◽  
Spectral Signatures ◽  
Operating Modes ◽  
Gan Hemt ◽  
Spectrally Resolved ◽  
Performance Variations

Abstract Non-degraded and degraded AlGaN/GaN HEMT devices have been characterized electrically and investigated in various operating modes using integral and spectrally resolved photon emission (PE). In degraded devices the PE dependence on the gate voltage differs from the non-degraded devices. Various types of dependencies on the gate voltage have been identified when investigating local degradation sites. PE spectroscopy was performed at various bias conditions. For both devices broad spectra have been obtained in a wavelength regime from visible to near-infrared, including local performance variations. Signatures of the degradation have been determined in the electrical characterization, in integral PE distribution and in the PE spectrum.

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