Broadband time‐domain‐reflectometry dielectric spectroscopy using variable‐time‐scale sampling

Abstract In this paper, we demonstrate cases for actual short and open failures in FCB (Flip Chip Bonding) substrates by using novel non-destructive techniques, known as SSM (Scanning Super-conducting Quantum Interference Device Microscopy) and Terahertz TDR (Time Domain Reflectometry) which is able to pinpoint failure locations. In addition, the defect location and accuracy is verified by a NIR (Near Infra-red) imaging system which is also one of the commonly used non-destructive failure analysis tools, and good agreement was made.

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Super-Conducting Quantum Interference Device Technique: 3-D Localization of a Short within a Flip Chip Assembly

ISTFA 2001: Conference Proceedings from the 27th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2001p0069 ◽

2001 ◽

Author(s):

Kendall Scott Wills ◽

Omar Diaz de Leon ◽

Kartik Ramanujachar ◽

Charles P. Todd

Keyword(s):

Form Factor ◽

Failure Analysis ◽

Time Domain ◽

Quantum Interference ◽

Flip Chip ◽

Time Domain Reflectometry ◽

Interfacial Region ◽

Precise Localization ◽

Super Conducting ◽

Accuracy Of Measurement

Abstract In the current generations of devices the die and its package are closely integrated to achieve desired performance and form factor. As a result, localization of continuity failures to either the die or the package is a challenging step in failure analysis of such devices. Time Domain Reflectometry [1] (TDR) is used to localize continuity failures. However the accuracy of measurement with TDR is inadequate for effective localization of the failsite. Additionally, this technique does not provide direct 3-Dimenstional information about the location of the defect. Super-conducting Quantum Interference Device (SQUID) Microscope is useful in localizing shorts in packages [2]. SQUID microscope can localize defects to within 5um in the X and Y directions and 35um in the Z direction. This accuracy is valuable in precise localization of the failsite within the die, package or the interfacial region in flipchip assemblies.

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Failure Analysis of Broken Stitch Bonds in TSSOP Packages Using Scanning Acoustic Microscopy (SAM) and Time Domain Reflectometry (TDR)

ISTFA 2004: Conference Proceedings from the 30th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2004p0623 ◽

2004 ◽

Author(s):

Bilal Abd-AlRahman ◽

Corey Lewis ◽

Todd Simons

Keyword(s):

Failure Analysis ◽

Mechanical Stress ◽

Time Domain ◽

Open Circuit ◽

Time Domain Reflectometry ◽

Acoustic Microscopy ◽

Scanning Acoustic Microscopy ◽

Root Cause ◽

Analysis Application

Abstract A failure analysis application utilizing scanning acoustic microscopy (SAM) and time domain reflectometry (TDR) for failure analysis has been developed to isolate broken stitch bonds in thin shrink small outline package (TSSOP) devices. Open circuit failures have occurred in this package due to excessive bending of the leads during assembly. The tools and their specific application to this technique as well as the limitations of C-SAM, TDR and radiographic analyses are discussed. By coupling C-SAM and TDR, a failure analyst can confidently determine whether the cause of an open circuit in a TSSOP package is located at the stitch bond. The root cause of the failure was determined to be abnormal mechanical stress placed on the pins during the lead forming operation. While C-SAM and TDR had proven useful in the analysis of TSSOP packages, it can potentially be expanded to other wire-bonded packages.

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Time Domain Reflectometry Technique for Failure Analysis

ISTFA 2004: Conference Proceedings from the 30th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2004p0616 ◽

2004 ◽

Author(s):

Teoh King Long ◽

Ko Yin Fern

Keyword(s):

Failure Analysis ◽

Time Domain ◽

Time Domain Reflectometry ◽

Fault Isolation ◽

Reference Plane ◽

First Case ◽

Main Emphasis ◽

Plastic Ball ◽

Solder Balls ◽

Non Destructive

Abstract In time domain reflectometry (TDR), the main emphasis lies on the reflected waveform. Poor probing contact is one of the common problems in getting an accurate waveform. TDR probe normalization is essential before measuring any TDR waveforms. The advantages of normalization include removal of test setup errors in the original test pulse and the establishment of a measurement reference plane. This article presents two case histories. The first case is about a Plastic Ball Grid Array package consisting of 352 solder balls where the open failure mode was encountered at various terminals after reliability assessment. In the second, a three-digit display LED suspected of an electrical short failure was analyzed using TDR as a fault isolation tool. TDR has been successfully used to perform non-destructive fault isolation in assisting the routine failure analysis of open and short failure. It is shown to be accurate and reduces the time needed to identify fault locations.

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