Mr. David Vallett's scientific contributions

Publications (7)

Conference Paper
Backside MCI and LIT are used on a low-resistance power supply short through a full-thickness silicon die and subsequently on the same device immediately above the active layer after global contour-milling of substantially all the substrate silicon. The work will demonstrate the advantages of this non-destructive edge-to-edge deprocessing method ca...
Conference Paper
Space Domain Reflectometry (SDR) is a newly developed non-destructive failure analysis (FA) technique for localizing open defects in both packages and dies through mapping in space domain the magnetic field produced by a radio frequency (RF) current induced in the sample, herein the name Space Domain Reflectometry. The technique employs a scanning...
Conference Paper
Lock-in thermography and magnetic current imaging are emerging as the two image-based fault isolation methods most capable of meeting the challenges of short and open defect localization in thick, opaque assemblies. Such devices are rapidly becoming prevalent as 3D integration begins to ramp up production. This paper expands on previously published...
Conference Paper
The relative effectiveness of lock-in thermography and magnetic current imaging for identifying defects in packaged ICs was studied by directly comparing results on the same three devices. One known (in-lab fabricated) and two unknown (field return) defects were studied in organic flip-chip and wirebond configurations. Both methods succeeded in ide...
Conference Paper
A wide variety of physical methods exist for isolating faults in IC die and packages. These techniques are based predominantly on imaging thermal, photonic, and magnetic activity associated with defects or the circuits they affect. This tutorial will cover the capabilities, and limitations of magnetic field and force imaging using superconducting,...

Citations

... Given a sufficiently sensitive magnetometer and adequate spatial resolution, the current path can be inferred from this information. Existing DC magnetic sensing technology utilizes superconducting quantum interference devices (SQUID) [9,10] and giant magnetoresistance (GMR) magnetometers [11]. SQUIDs are also capable of locating opens by detecting an AC signal propagating through the path [12][13][14]. ...
... A current carrying conductor generates magnetic field according to the Biot-Savart law [6]. MCI is a sub technique of MFI, and due to the capability of MFI to "look through" any types of materials that are physically covering the signal, one can achieve global imaging without physical deprocessing [7,8]. MCI utilizes two types of sensors: Superconducting Quantum Interference Device (SQUID) sensor for low current and large working distances, including quick overview scans at die level, and a Giant Magneto Resistance (GMR) sensor for sub micron resolution current imaging front side at wafer/die level [4]. ...
... Previous publications have analyzed MCI vs. other common fault isolation techniques (i.e. PEM, LSM/TIVA, LIT, and liquid crystal) [12][13][14]. These results however are dated and/or limited in scope, examining only SQUID-based MCI and looking at specific defect types in just a few different sample form-factors. ...
... Techniques such as magnetic microscopy have also seen an increase in use, the advantage being that every current flow generates a local magnetic field which is not affected by the surrounding materialthe technique can be further enhanced if combined with magnetic simulations [4]. However, this technique lacks in resolution and data acquisition speed in 3D-IC fault localisation [5] [6] Generally, the TDR technique is well established as a very rapid approach to provide fault detection. In this technique the impedance changes within the device under test (DUT) trace reflect a portion of the input pulse back to the source [7]. ...