Comparative Study of Extraction Efficiencies of the Three Sample Preparation Techniques

Abstract This paper presents a comparative study of backside sample preparation techniques with applicability to conventional as well as flip chip package types. We will cover mechanical (grinding and milling tools), chemical (wet and dry chemistries) and other approaches such as laser ablation. Backside sample preparation is very challenging. The preparation process flow starts with decapsulation of the ceramic or plastic package, continues with the die paddle removal, silicon thinning and finishes with silicon polishing. The techniques involved include mechanical, chemical and other novel approaches for ceramic and plastic package. Today, only CNC milling can cover the whole process for almost any kind of packages. Nevertheless, photo ablation is a rising technology for package decapsulation. In addition, chemical wet etch can be used to perform silicon thinning and polishing. We will illustrate the complexity of the process through examples. The first one is a ceramic package where the main issue is the hardness of ceramic. The second one is a TSOP package where the main challenge is the chip scaled package. Both will be observed through the IR emission microscope to demonstrate the efficiency of the preparation.

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A Freeze Shadow Technique for the Preparation of Soft Paint Latexes for Electron Microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100079097 ◽

1977 ◽

Vol 35 ◽

pp. 314-315

Author(s):

Earl R. Walter ◽

Glen H. Bryant

Keyword(s):

Sample Preparation ◽

High Vacuum ◽

Vacuum System ◽

Latex Particles ◽

New Methods ◽

Diffusion Pump ◽

Film Forming ◽

Routine Basis ◽

Distribution Studies ◽

Preparation Techniques

With the development of soft, film forming latexes for use in paints and other coatings applications, it became desirable to develop new methods of sample preparation for latex particle size distribution studies with the electron microscope. Conventional latex sample preparation techniques were inadequate due to the pronounced tendency of these new soft latex particles to distort, flatten and fuse on the substrate when they dried. In order to avoid these complications and obtain electron micrographs of undistorted latex particles of soft resins, a freeze-dry, cold shadowing technique was developed. The method has now been used in our laboratory on a routine basis for several years.The cold shadowing is done in a specially constructed vacuum system, having a conventional mechanical fore pump and oil diffusion pump supplying vacuum. The system incorporates bellows type high vacuum valves to permit a prepump cycle and opening of the shadowing chamber without shutting down the oil diffusion pump. A baffeled sorption trap isolates the shadowing chamber from the pumps.

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Advanced TEM sample preparation techniques for submicron Si devices

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100138956 ◽

1995 ◽

Vol 53 ◽

pp. 516-517 ◽

Cited By ~ 1

Author(s):

P. B. Basham ◽

H. L. Tsai

Keyword(s):

Sample Preparation ◽

Process Development ◽

Light Transmission ◽

Specific Area ◽

Turnaround Time ◽

Small Hole ◽

Area Of Interest ◽

Transmission Electron ◽

Polished Side ◽

Preparation Techniques

The use of transmission electron microscopy (TEM) to support process development of advanced microelectronic devices is often challenged by a large amount of samples submitted from wafer fabrication areas and specific-spot analysis. Improving the TEM sample preparation techniques for a fast turnaround time is critical in order to provide a timely support for customers and improve the utilization of TEM. For the specific-area sample preparation, a technique which can be easily prepared with the least amount of effort is preferred. For these reasons, we have developed several techniques which have greatly facilitated the TEM sample preparation.For specific-area analysis, the use of a copper grid with a small hole is found to be very useful. With this small-hole grid technique, TEM sample preparation can be proceeded by well-established conventional methods. The sample is first polished to the area of interest, which is then carefully positioned inside the hole. This polished side is placed against the grid by epoxy Fig. 1 is an optical image of a TEM cross-section after dimpling to light transmission.

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Novel Failure Analysis Sample Preparation Techniques for PoP Packaging

ISTFA 2012: Conference Proceedings from the 38th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2012p0578 ◽

2012 ◽

Author(s):

Ng Sea Chooi ◽

Chor Theam Hock ◽

Ma Choo Thye ◽

Khoo Poh Tshin ◽

Dan Bockelman

Keyword(s):

Sample Preparation ◽

Failure Analysis ◽

Failure Mechanisms ◽

Preparation Process ◽

Space Saving ◽

Optical Probing ◽

Preparation Techniques

Abstract Trends in the packaging of semiconductors are towards miniaturization and high functionality. The package-on-package(PoP) with increasing demands is beneficial in cost and space saving. The main failure mechanisms associated with PoP technology, including open joints and warpage, have created a lot of challenges for Assembly and Failure Analysis (FA). This paper outlines the sample preparation process steps to overcome the challenges to enable successful failure analysis and optical probing.

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Sample Preparation Challenges In WLCSP Epoxy Underfill Coating Removal

ISTFA 2012: Conference Proceedings from the 38th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2012p0471 ◽

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.

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A New Method of Wafer Level Plan View TEM Sample Preparation by DualBeam

ISTFA 2008: Conference Proceedings from the 34th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2008p0168 ◽

2008 ◽

Author(s):

Hyoung H. Kang ◽

Michael A. Gribelyuk ◽

Oliver D. Patterson ◽

Steven B. Herschbein ◽

Corey Senowitz

Keyword(s):

Sample Preparation ◽

Ex Situ ◽

Wafer Level ◽

Cross Sectional ◽

Plan View ◽

Manufacturing Line ◽

Transmission Electron ◽

Thin Lamella ◽

Preparation Techniques

Abstract Cross-sectional style transmission electron microscopy (TEM) sample preparation techniques by DualBeam (SEM/FIB) systems are widely used in both laboratory and manufacturing lines with either in-situ or ex-situ lift out methods. By contrast, however, the plan view TEM sample has only been prepared in the laboratory environment, and only after breaking the wafer. This paper introduces a novel methodology for in-line, plan view TEM sample preparation at the 300mm wafer level that does not require breaking the wafer. It also presents the benefit of the technique on electrically short defects. The methodology of thin lamella TEM sample preparation for plan view work in two different tool configurations is also presented. The detailed procedure of thin lamella sample preparation is also described. In-line, full wafer plan view (S)TEM provides a quick turn around solution for defect analysis in the manufacturing line.

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