Strain-gauge mapping of die surface stresses

Gee, S.A.; Bogert, W.F. van den; Akylas, V.; Shelton, Roger

doi:10.1109/33.49020

Cited by 59 publications

(7 citation statements)

References 8 publications

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“…Several studies have suggested that the edge of the die undergoes the most severe stress at increased temperatures. [5][6][7] Since the test vehicles have symmetrical geometry, the strain distribution is expected to be symmetrical with respect to the center of the die edge. Hence, synchrotron x-ray scans were conducted at the edge of the die to obtain sufficient information in the limited beam time.…”

Section: Measurement Of Real Strainmentioning

confidence: 99%

“…1,2 The stresses in dies that are induced by different layers of materials, including the underfill, have also been discussed. 3,4 In 1989, Gee et al 5 used a strain gage to measure the stress on the surface of a chip undergoing thermal shock. The results indicated that the principal stress was highest at the center of the die and uniform over a large region.…”

Section: Introductionmentioning

confidence: 99%

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In Situ Measurements of Thermal and Electrical Effects of Strain in Flip-Chip Silicon Dies Using Synchrotron Radiation X-rays

Tsai

Kao

et al. 2009

Journal of Elec Materi

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Section: Measurement Of Real Strainmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

In Situ Measurements of Thermal and Electrical Effects of Strain in Flip-Chip Silicon Dies Using Synchrotron Radiation X-rays

Tsai

Kao

et al. 2009

Journal of Elec Materi

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“…In molding processes for instance, the different thermal expansion coefficients of the chip and the molding polymer account for a large part of the yield, stability, and reliability issues during IC packaging and operation. Therefore, stress sensor arrays have been used to map the stress distribution on the surface of the chip to characterize and improve the packaging process [74][75][76].…”

Section: Stress Monitoringmentioning

confidence: 99%

Advanced silicon microstructures, sensors, and systems

Oliver

Gaspar

Ruther

2007

IEEJ Transactions Elec Engng

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This paper presents the progress in silicon-based biomedical microstructures, material characterization techniques, and mechanical microsystems by the authors' research team. Microneedle and microelectrode arrays with fluidic through-wafer vias and electrical contacts were developed. The structures are designed for dermatological and biological applications such as allergy testing, surface electromyography, and spatially resolved impedance spectroscopy. The characterization of thin films has relied on the bulge test. By the formulation of more powerful models, the application range of the bulge test was extended to elastically supported thin-film multilayers. This enables the mechanical properties of thin films to be determined reliably. Finally, progress in the operation and application of novel stress sensors based on CMOS diffusions and field effect transistors and exploiting the pseudo-Hall effect is reported. Their integration into powerful single-chip microsystems is described. Applications include stress mapping, force and torque measurements, and tactile surface probing of microcomponents. 

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“…Distorted samples are then filtered out by using low-pass filtering. The nail sensor can suffer from changing bias, due to temperature change, from undesired induction in the circuit [26], or from battery aging. This bias can be removed estimating continuously the bias, and excluding it using Kalman filtering similar to [27].…”

Section: B Preprocessingmentioning

confidence: 99%

Back to Finger-Writing: Fingertip Writing Technology Based on Pressure Sensing

et al. 2020

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Handwriting was since the start of the history, a higher expression of human skills, and was used for documentation of experiences, and for communication. Existing writing technology require a writing tool, like a pen, and a dedicated writing surface, like paper, or more recently an electronic tablet. These accessories of writing, of writing tool and service, are not available in many daily life situations. Furthermore, the writing accessories, are not natural, in many cases are not ergonomic, and thus can cause fatigue, and in extreme cases contribute to muscular and neurological diseases. In this work, we suggest to step back in history and step forward in technology, and to create, for the first time, an alternate writing solution without any accessories, using one own finger as writing tool, and write on almost any surface. For this, we used directional pressure sensors attached to the fingernail. Changes in the pressure induced on the fingertip in different directions while writing, are projected to the fingernail, and then assessed as a voltage pattern by the sensor. Decoding the pattern, can reveal symbols like letters, punctuations, and writing commands. In this paper, we describe the new pressure sensing modality and tailor processing methods. We tested the new technology on two subjects having different writing patterns while writing alphabet and sentences on different surfaces. We reached letter detection of over 80% while writing on a table, and the word detection rate, was near 70%, after applying the correction algorithm include language priors. The results of this work can revolutionize the way people write and communicate using more convenient, and more approachable, fingertip writing. INDEX TERMS Handwriting recognition, human machine interface, natural language processing.

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Strain-gauge mapping of die surface stresses

Cited by 59 publications

References 8 publications

In Situ Measurements of Thermal and Electrical Effects of Strain in Flip-Chip Silicon Dies Using Synchrotron Radiation X-rays

In Situ Measurements of Thermal and Electrical Effects of Strain in Flip-Chip Silicon Dies Using Synchrotron Radiation X-rays

Advanced silicon microstructures, sensors, and systems

Back to Finger-Writing: Fingertip Writing Technology Based on Pressure Sensing

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