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Author

Tetsu Tanaka

Other affiliations: NTT DoCoMo, Tokyo Medical and Dental University, Fujitsu  ...read more
Bio: Tetsu Tanaka is an academic researcher from Tohoku University. The author has contributed to research in topics: Wafer & Chip. The author has an hindex of 38, co-authored 406 publications receiving 10375 citations. Previous affiliations of Tetsu Tanaka include NTT DoCoMo & Tokyo Medical and Dental University.
Topics: Wafer, Chip, Wafer bonding, Interposer, Flip chip


Papers
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Proceedings ArticleDOI
01 Jun 2021
TL;DR: In this paper, a die-shift issue for the tiny chips in die-first FOWLP was addressed by using a new anchoring layer technique to drastically reduce the shift within $2.7\ \mu\mathrm{m}$ including assembly positioning errors.
Abstract: This paper deals with a flexible 3D-IC system fabrication methodology. Mini-LEDs and 3D-IC chiplets divided from a large 3D-IC with Cu-TSVs are embedded in an elastomer PDMS based on die-first FOWLP for heterogeneously integrating them into Smart Skin Display as a biomedical/wearable FHE (flexible hybrid electronics). We address a serious die-shift issue for the tiny chips in die-first FOWLP by using a new anchoring layer technique to drastically reduce the shift within $2.7\ \mu\mathrm{m}$ including assembly positioning errors. The mechanical/electrical properties of the flexible array of 3D-IC chiplets are characterized before and after repeated bending with a curvature radius of 10 mm. In addition, stress neutral axes are designed to stably endure bending cycle applicable to the biomedical/wearable FHE with multi-level metallization.

3 citations

Proceedings ArticleDOI
16 Aug 2012
TL;DR: Investigation of the induced thermo-mechanical stress in 3D-LSI Si die/wafer after wafer thinning and bonding using micro-Raman spectroscopic technique revealed that W-TSV has induced less thermosensitive stress in LSI Si, whereas the Cu-TSVs has induced large amount of stress.
Abstract: High density 3D-LSI with W-TSV for signal line and Cu-TSV for power/GND line, and Cu-TSV containing W stress absorbing layers were investigated for the induced thermo-mechanical stress in 3D-LSI Si die/wafer after wafer thinning and bonding using micro-Raman spectroscopic technique. Stress mapping analysis revealed that W-TSV has induced less thermo-mechanical stress in LSI Si, whereas the Cu-TSV has induced large amount of stress. Further, Cu-TSV with W stress absorbing layer showed much reduced residual thermo-mechanical stress as compared to the pure Cu-TSV, i.e for 6 μm diameter Cu-TSV with W layer showed −300 MPa of compressive stress after heating at 400 °C. This property can be readily employed to minimize the residual thermo-mechanical stress in the bonded high density 3D-LSI.

3 citations

Proceedings ArticleDOI
23 Nov 2015
TL;DR: This work presents design guideline of microbump layout which can suppress the local bending stress in 3D-stacked several thin IC chips to realize 3D IC with high reliability.
Abstract: Three-dimensional IC (3D IC) has attracted much attention as a promising method to enhance IC performance. Recently, great interests in mechanical reliability are increasing among 3D IC researchers for production of 3D IC. Conventional 3D ICs consist of vertically stacked several thin IC chips those are electrically connected with lots of through-Si vias (TSVs) and metal microbumps. Metal microbumps are surrounded by organic adhesive called underfill material. In general, coefficient of thermal expansion (CTE) of the underfill material is larger than that of metal microbumps. This CTE difference induces local bending stress in thinned IC chips. This local bending stress would affect transistor reliability in thinned IC chips. Therefore, we should suppress the local bending stress to realize 3D IC with high reliability. In this work, we present design guideline of microbump layout which can suppress the local bending stress in 3D-stacked several thin IC chips.

3 citations

Journal ArticleDOI
TL;DR: In this paper, the effects of heat treatments on the soft magnetic properties and the temperature dependency of the properties of the Sendust alloys (Fe-9∼10wt%Si-5∼7 wt%A1 ternary alloys) were investigated.
Abstract: The effects of heat treatments on the soft magnetic properties and the temperature dependency of the properties of the Sendust alloys (Fe-9∼10wt%Si-5∼7 wt%A1 ternary alloys) were investigated. The quenching from the various temperatures(400°C∼800°C) was performed on the samples control-cooled(100°C/h) after homogenization(1100°C × 5h). It is found that the quenching temperature considerably affected the soft magnetic properties, and that the quenching temperature giving the good properties was varied with the alloy composition. The obtained highest initial permeability at 20°C was 380 000 for an Fe-9.7wt%Si-5.4wt%A1 alloy when it was quenched from 400°C. This value is about ten times higher than that of conventional Sendust alloys, and superior to 220 000 of Permalloy (Fe-79wt%Ni-5wt%Mo).

3 citations

Proceedings ArticleDOI
01 Oct 2018
TL;DR: In this article, the authors describe advanced assembly technologies based on a new tape expansion technique with a selective UV irradiation method for the application of FOWLP (Fan-Out Wafer-Level Packaging) with millimeter-scale dies and micro-LED display with several tens of micrometer-scaled dielets.
Abstract: This paper describes advanced assembly technologies based on a new tape expansion technique with a selective UV irradiation method for the application of FOWLP (Fan-Out Wafer-Level Packaging) with millimeter-scale dies and micro-LED display with several tens of micrometer-scaled dielets. The assembly technologies allow us to uniformly expand expansion tapes in all direction and array the dies/dielets at the regular pitches desired for their products. We demonstrate the uniform expansion of an expansion tape with 3-mm-square Si dies and 50-μm-square Si dielets using selectively irradiated UV light through a photomask.

3 citations


Cited by
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Journal ArticleDOI
11 Jun 1998-Nature
TL;DR: The complete genome sequence of the best-characterized strain of Mycobacterium tuberculosis, H37Rv, has been determined and analysed in order to improve the understanding of the biology of this slow-growing pathogen and to help the conception of new prophylactic and therapeutic interventions.
Abstract: Countless millions of people have died from tuberculosis, a chronic infectious disease caused by the tubercle bacillus. The complete genome sequence of the best-characterized strain of Mycobacterium tuberculosis, H37Rv, has been determined and analysed in order to improve our understanding of the biology of this slow-growing pathogen and to help the conception of new prophylactic and therapeutic interventions. The genome comprises 4,411,529 base pairs, contains around 4,000 genes, and has a very high guanine + cytosine content that is reflected in the biased amino-acid content of the proteins. M. tuberculosis differs radically from other bacteria in that a very large portion of its coding capacity is devoted to the production of enzymes involved in lipogenesis and lipolysis, and to two new families of glycine-rich proteins with a repetitive structure that may represent a source of antigenic variation.

7,779 citations

Journal ArticleDOI
TL;DR: Antiinflammatory therapy targeting the interleukin‐1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid‐level lowering.
Abstract: BackgroundExperimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. MethodsWe conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. ResultsAt 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in t...

5,660 citations

Journal ArticleDOI
31 Aug 2000-Nature
TL;DR: It is proposed that the size and complexity of the P. aeruginosa genome reflect an evolutionary adaptation permitting it to thrive in diverse environments and resist the effects of a variety of antimicrobial substances.
Abstract: Pseudomonas aeruginosa is a ubiquitous environmental bacterium that is one of the top three causes of opportunistic human infections. A major factor in its prominence as a pathogen is its intrinsic resistance to antibiotics and disinfectants. Here we report the complete sequence of P. aeruginosa strain PAO1. At 6.3 million base pairs, this is the largest bacterial genome sequenced, and the sequence provides insights into the basis of the versatility and intrinsic drug resistance of P. aeruginosa. Consistent with its larger genome size and environmental adaptability, P. aeruginosa contains the highest proportion of regulatory genes observed for a bacterial genome and a large number of genes involved in the catabolism, transport and efflux of organic compounds as well as four potential chemotaxis systems. We propose that the size and complexity of the P. aeruginosa genome reflect an evolutionary adaptation permitting it to thrive in diverse environments and resist the effects of a variety of antimicrobial substances.

4,220 citations