Large Scale Photodesmear for Via Residue Cleaning in High Density Interconnect substrates

2015 ◽  
Vol 2015 (1) ◽  
pp. 000465-000468 ◽  
Author(s):  
Tomoyuki Habu ◽  
Masahito Namai ◽  
Akira Aiba ◽  
Hajime Kikuiri ◽  
Shun Maruyama ◽  
...  
Keyword(s):  
Large Scale ◽  
Vacuum Ultraviolet ◽  
Dielectric Material ◽  
Low Cost ◽  
Peel Strength ◽  
Dielectric Surface ◽  
Film Material ◽  
Chemical Waste ◽  
Process Step ◽  
Aspect Ratios

Smear residue from the build-up dielectric material is left at the bottom of the microvia after laser drill process which, if not cleaned, poses risk to the electrical functionality of the device. Thus, microvia cleanliness is the key to a reliable and electrically functional device. Currently, industry employs a wet process to clean the etch residue that results in significant chemical waste. Here, we evaluated an alternative, but effective Photodesmear method that provides a low cost of ownership and almost negligible environmental impact. We have demonstrated in IMAPS 2013 that this process can achieve residue- and silica filler free via bottoms by a two-step process: i) illuminating 172 nm vacuum ultraviolet light (VUV) on the panels, resulting in a photochemical ashing, and ii) a water clean. This process does not reduce the surface energy of the build-up material, thus not impacting the downstream processes. The main technical challenge in developing Photodesmear technology will be panel level uniformity in cleaning all the microvias within the same process step. We have demonstrated that our process can achieve a highly uniform treatment over 510 mm wide panels. The process was optimized to clean microvias with a range of aspect ratios on insulating film (material N) drilled by CO2 laser. The microvia bottoms were also found to be clean when the vias were drilled by UV laser to test the desmear capability. The quality of the Photodesmear was tested by measuring the peel strength between electrolytically plated Cu and dielectric surface, and by performing the quick via pull (QVP) to verify the failing interface. We found high peel strength of 0.7 kgf/cm when sputtered Cu seed layer was used. QVP experiments confirmed that the via residue is cleaned effectively since the interface between the plated Cu and the underlying Cu pad did not fail. This study shows that Photodesmear process is capable to produce clean vias along with acceptable peel strength. Future issues are to research the reliability, productivity, and cost of the Photodesmear process to compare with the existing process.

A Photo-Desmear Method for Via Residue Removal Using a VUV Light Source

2013 ◽  
Vol 2013 (1) ◽  
pp. 000492-000495 ◽  
Author(s):  
Tomoyuki Habu ◽  
Shintaro Yabu ◽  
Kenichi Hirose ◽  
Hiroki Horibe ◽  
Toru Fujinami ◽  
...  
Keyword(s):  
Vacuum Ultraviolet ◽  
Uv Light ◽  
Cost Effective ◽  
Dielectric Surface ◽  
Surface Cleaning ◽  
Electrical Performance ◽  
Copper Plating ◽  
Chemical Waste ◽  
Residue Removal ◽  
Photochemical Decomposition

The desmear process of removing via residue after laser drill in substrate manufacturing is a critical step for reliability and electrical performance. Cost effective and environmentally clean desmear processes are industry-wide objectives, as the current wet desmear process results in significant chemical waste and regular bath replacement. Here, we evaluated an effective photo desmear method targeting a low total cost of ownership and negligible environmental impact. This method achieves residue and silica free via bottoms with the use of 172nm vacuum ultraviolet light (VUV) photo-chemical ashing followed by water clean. Studies of organic molecular photochemical decomposition by short wavelength UV light are widely reported and have been applied for purposes such as surface cleaning and improving wettability and are naturally extendable to via residue removal. Scanning electron microscope (SEM) and energy dispersed X-ray spectroscopy (EDX) reveal that the application of VUV desmear results in residue free microvia without negatively affecting via shape or the dielectric surface. In addition, the surface remains highly wettable, which aids downstream copper plating. The high reaction rate, absence of wet chemistry, and creation of surfaces amenable for subsequent copper plating make this dry desmear process a strong candidate for future applications in substrate manufacturing.

Integrated Thin Film Capacitor Arrays Utilizing Sol-Gel Derived Ferroelectrics

1999 ◽  
Vol 596 ◽  
Author(s):  
David Liu ◽  
Steve Makl ◽  
Robert H. Heistand
Keyword(s):  
Thin Film ◽  
Large Scale ◽  
Dielectric Material ◽  
Low Cost ◽  
Sol Gel ◽  
Capacitance Measurement ◽  
Frequency Independent ◽  
Film Dielectric ◽  
Independent Behavior ◽  
Capacitor Arrays

AbstractNiobium-doped lead zircomate titanate (PNZT) thin film dielectric material has been produced on a large scale using a thick-coating sol-gel process. The material has been applied to the fabrication of commercial integrated capacitor array devices. Compared to conventional processes, this low-cost, long-shelf-life procedure had at least a 4-fold processing time enhancement. The specific capacitance of 2500 nF/cm2 and integrated density of over 200 component/cm2 have been demonstrated. The frequency domain capacitance measurement of integrated PNZT capacitors exhibits a frequency-independent behavior up to 2 GHz when a DC bias is applied. Leakage-voltage dependence follows the space-charge-limited-current (SCLC) mechanism. The fabricated integrated capacitor arrays pass the industrial standard of reliability for discrete multilayer capacitors.

scholarly journals Hydrogel Patterns in Microfluidic Devices by Do-It-Yourself UV-Photolithography Suitable for Very Large-Scale Integration

Micromachines ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 479
Author(s):  
Anthony Beck ◽  
Franziska Obst ◽  
Mathias Busek ◽  
Stefan Grünzner ◽  
Philipp Mehner ◽  
...  
Keyword(s):  
Large Scale ◽  
Low Cost ◽  
Stimuli Responsive ◽  
Single Chip ◽  
Active Components ◽  
Chemical Laboratory ◽  
Fast Analysis ◽  
Aspect Ratios ◽  
Micro Patterning ◽  
Do It Yourself

The interest in large-scale integrated (LSI) microfluidic systems that perform high-throughput biological and chemical laboratory investigations on a single chip is steadily growing. Such highly integrated Labs-on-a-Chip (LoC) provide fast analysis, high functionality, outstanding reproducibility at low cost per sample, and small demand of reagents. One LoC platform technology capable of LSI relies on specific intrinsically active polymers, the so-called stimuli-responsive hydrogels. Analogous to microelectronics, the active components of the chips can be realized by photolithographic micro-patterning of functional layers. The miniaturization potential and the integration degree of the microfluidic circuits depend on the capability of the photolithographic process to pattern hydrogel layers with high resolution, and they typically require expensive cleanroom equipment. Here, we propose, compare, and discuss a cost-efficient do-it-yourself (DIY) photolithographic set-up suitable to micro-pattern hydrogel-layers with a resolution as needed for very large-scale integrated (VLSI) microfluidics. The achievable structure dimensions are in the lower micrometer scale, down to a feature size of 20 µm with aspect ratios of 1:5 and maximum integration densities of 20,000 hydrogel patterns per cm². Furthermore, we demonstrate the effects of miniaturization on the efficiency of a hydrogel-based microreactor system by increasing the surface area to volume (SA:V) ratio of integrated bioactive hydrogels. We then determine and discuss a correlation between ultraviolet (UV) exposure time, cross-linking density of polymers, and the degree of immobilization of bioactive components.

Low Temperature Synthesis of TiO2 Nanorods with Tunable Aspect Ratios from Ti and NH4Cl Powders

2010 ◽  
Vol 97-101 ◽  
pp. 2148-2151
Author(s):  
Yan Liu ◽  
Yong Cai Zhang ◽  
Ming Zhang
Keyword(s):  
Low Temperature ◽  
Large Scale ◽  
Low Cost ◽  
Scale Production ◽  
X Ray Diffraction ◽  
Molar Ratios ◽  
Aspect Ratios ◽  
Large Scale Production ◽  
Tio2 Nanomaterials ◽  
Electronic Microscope

TiO2 nanorods with tunable aspect ratios were synthesized directly via heating different molar ratios of Ti and NH4Cl powders in air at 400 °C for 3 h. The resultant products have been characterized by means of X-ray diffraction (XRD), Raman spectra, and field emission scanning electronic microscope (FESEM). The proposed method is of simpleness, low temperature and low cost, which may be suitable for large scale production of multifunctional TiO2 nanomaterials

An Assessment of a Low-Cost Wastewater Disposal System after Twenty-Five Years of Operation

1987 ◽  
Vol 19 (5-6) ◽  
pp. 701-710 ◽  
Author(s):  
B. L. Reidy ◽  
G. W. Samson
Keyword(s):  
Large Scale ◽  
Low Cost ◽  
Wastewater Disposal ◽  
Industrial Base ◽  
Industrial Wastewaters ◽  
The Past ◽  
Gasification Process ◽  
Appropriate Treatment ◽  
Environmentally Safe ◽  
Coal Resource

A low-cost wastewater disposal system was commissioned in 1959 to treat domestic and industrial wastewaters generated in the Latrobe River valley in the province of Gippsland, within the State of Victoria, Australia (Figure 1). The Latrobe Valley is the centre for large-scale generation of electricity and for the production of pulp and paper. In addition other industries have utilized the brown coal resource of the region e.g. gasification process and char production. Consequently, industrial wastewaters have been dominant in the disposal system for the past twenty-five years. The mixed industrial-domestic wastewaters were to be transported some eighty kilometres to be treated and disposed of by irrigation to land. Several important lessons have been learnt during twenty-five years of operating this system. Firstly the composition of the mixed waste stream has varied significantly with the passage of time and the development of the industrial base in the Valley, so that what was appropriate treatment in 1959 is not necessarily acceptable in 1985. Secondly the magnitude of adverse environmental impacts engendered by this low-cost disposal procedure was not imagined when the proposal was implemented. As a consequence, clean-up procedures which could remedy the adverse effects of twenty-five years of impact are likely to be costly. The question then may be asked - when the total costs including rehabilitation are considered, is there really a low-cost solution for environmentally safe disposal of complex wastewater streams?

scholarly journals Rapid, large-scale species discovery in hyperdiverse taxa using 1D MinION sequencing

BMC Biology ◽  
2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Amrita Srivathsan ◽  
Emily Hartop ◽  
Jayanthi Puniamoorthy ◽  
Wan Ting Lee ◽  
Sujatha Narayanan Kutty ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Large Scale ◽  
Low Cost ◽  
Small Body ◽  
Small Subset ◽  
Similar Species ◽  
Large Species ◽  
Morphological Examination ◽  
Species Discovery ◽  
Short Period

Abstract Background More than 80% of all animal species remain unknown to science. Most of these species live in the tropics and belong to animal taxa that combine small body size with high specimen abundance and large species richness. For such clades, using morphology for species discovery is slow because large numbers of specimens must be sorted based on detailed microscopic investigations. Fortunately, species discovery could be greatly accelerated if DNA sequences could be used for sorting specimens to species. Morphological verification of such “molecular operational taxonomic units” (mOTUs) could then be based on dissection of a small subset of specimens. However, this approach requires cost-effective and low-tech DNA barcoding techniques because well-equipped, well-funded molecular laboratories are not readily available in many biodiverse countries. Results We here document how MinION sequencing can be used for large-scale species discovery in a specimen- and species-rich taxon like the hyperdiverse fly family Phoridae (Diptera). We sequenced 7059 specimens collected in a single Malaise trap in Kibale National Park, Uganda, over the short period of 8 weeks. We discovered > 650 species which exceeds the number of phorid species currently described for the entire Afrotropical region. The barcodes were obtained using an improved low-cost MinION pipeline that increased the barcoding capacity sevenfold from 500 to 3500 barcodes per flowcell. This was achieved by adopting 1D sequencing, resequencing weak amplicons on a used flowcell, and improving demultiplexing. Comparison with Illumina data revealed that the MinION barcodes were very accurate (99.99% accuracy, 0.46% Ns) and thus yielded very similar species units (match ratio 0.991). Morphological examination of 100 mOTUs also confirmed good congruence with morphology (93% of mOTUs; > 99% of specimens) and revealed that 90% of the putative species belong to the neglected, megadiverse genus Megaselia. We demonstrate for one Megaselia species how the molecular data can guide the description of a new species (Megaselia sepsioides sp. nov.). Conclusions We document that one field site in Africa can be home to an estimated 1000 species of phorids and speculate that the Afrotropical diversity could exceed 200,000 species. We furthermore conclude that low-cost MinION sequencers are very suitable for reliable, rapid, and large-scale species discovery in hyperdiverse taxa. MinION sequencing could quickly reveal the extent of the unknown diversity and is especially suitable for biodiverse countries with limited access to capital-intensive sequencing facilities.

scholarly journals Synthesis of Polyaniline Coating on the Modified Fiber Ball and Application for Cr(VI) Removal

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Xiao Li Ma ◽  
Guang Tao Fei ◽  
Shao Hui Xu
Keyword(s):  
Waste Water ◽  
Large Scale ◽  
Ph Value ◽  
Low Cost ◽  
Strong Acid ◽  
Removal Capacity ◽  
Secondary Pollution ◽  
Potential Possibility ◽  
Fiber Ball ◽  
Maximum Removal

Abstract In this study, polyaniline (PANI) is prepared by means of chemical oxidization polymerization and directly loaded on the modified fiber ball (m-FB) to obtain macroscale polyaniline/modified fiber ball (PANI/m-FB) composite, and then its removal ability of Cr(VI) is investigated. The effects of different parameters such as contact time, pH value and initial concentration on Cr(VI) removal efficiency are discussed. The experimental results illustrate that the favorable pH value is 5.0 and the maximum removal capacity is measured to be 293.13 mg g−1. Besides, PANI/m-FB composites can be regenerated and reused after being treated with strong acid. The kinetic study indicates that the adsorption procedure is mainly controlled by chemical adsorption. More importantly, the macroscale of composites can avoid secondary pollution efficiently. Benefiting from the low cost, easy preparation in large scale, environmentally friendly, excellent recycling performance as well as high removal ability, PANI/m-FB composites exhibit a potential possibility to remove Cr(VI) from industrial waste water. Graphic Abstract The polyaniline (PANI) was coated on modified fiber ball (m-FB) to remove Cr(VI) in waste water, and this kind of PANI/m-FB composites can avoid secondary pollution efficiently due to its macrostructure. Furthermore, the removal capacity can reach to 291.13 mg/g and can be multiple reused.

scholarly journals Effects of Ag contents on the microstructure and SERS performance of self-grown Ag nanoparticles/Mo–Ag alloy films

2020 ◽  
Vol 9 (1) ◽  
pp. 751-759 ◽  
Author(s):  
Xinxin Lian ◽  
Yuanjiang Lv ◽  
Haoliang Sun ◽  
David Hui ◽  
Guangxin Wang
Keyword(s):  
Ag Nanoparticles ◽  
Large Scale ◽  
Low Cost ◽  
Film Surface ◽  
Time Domain Analysis ◽  
Alloy Film ◽  
Scale Production ◽  
Alloy Films ◽  
Surface Enhanced Raman ◽  
Ag Film

AbstractAg nanoparticles/Mo–Ag alloy films with different Ag contents were prepared on polyimide by magnetron sputtering. The effects of Ag contents on the microstructure of self-grown Ag nanoparticles/Mo–Ag alloy films were investigated using XRD, FESEM, EDS and TEM. The Ag content plays an important role in the size and number of uniformly distributed Ag nanoparticles spontaneously formed on the Mo–Ag alloy film surface, and the morphology of the self-grown Ag nanoparticles has changed significantly. Additionally, it is worth noting that the Ag nanoparticles/Mo–Ag alloy films covered by a thin Ag film exhibits highly sensitive surface-enhanced Raman scattering (SERS) performance. The electric field distributions were calculated using finite-difference time-domain analysis to further prove that the SERS enhancement of the films is mainly determined by “hot spots” in the interparticle gap between Ag nanoparticles. The detection limit of the Ag film/Ag nanoparticles/Mo–Ag alloy film for Rhodamine 6G probe molecules was 5 × 10−14 mol/L. Therefore, the novel type of the Ag film/Ag nanoparticles/Mo–Ag alloy film can be used as an ideal SERS-active substrate for low-cost and large-scale production.

SateLoc: A Virtual Fingerprinting Approach to Outdoor LoRa Localization Using Satellite Images

2021 ◽  
Vol 17 (4) ◽  
pp. 1-28
Author(s):  
Yuxiang Lin ◽  
Wei Dong ◽  
Yi Gao ◽  
Tao Gu
Keyword(s):  
Land Cover ◽  
Large Scale ◽  
Satellite Images ◽  
Low Cost ◽  
Tracking Error ◽  
Location Based Services ◽  
Distance Constraint ◽  
Combination Strategy ◽  
Land Cover Types ◽  
High Resolution Satellite Images

With the increasing relevance of the Internet of Things and large-scale location-based services, LoRa localization has been attractive due to its low-cost, low-power, and long-range properties. However, existing localization approaches based on received signal strength indicators are either easily affected by signal fading of different land-cover types or labor intensive. In this work, we propose SateLoc, a LoRa localization system that utilizes satellite images to generate virtual fingerprints. Specifically, SateLoc first uses high-resolution satellite images to identify land-cover types. With the path loss parameters of each land-cover type, SateLoc can automatically generate a virtual fingerprinting map for each gateway. We then propose a novel multi-gateway combination strategy, which is weighted by the environmental interference of each gateway, to produce a joint likelihood distribution for localization and tracking. We implement SateLoc with commercial LoRa devices without any hardware modification, and evaluate its performance in a 227,500-m urban area. Experimental results show that SateLoc achieves a median localization error of 43.5 m, improving more than 50% compared to state-of-the-art model-based approaches. Moreover, SateLoc can achieve a median tracking error of 37.9 m with the distance constraint of adjacent estimated locations. More importantly, compared to fingerprinting-based approaches, SateLoc does not require the labor-intensive fingerprint acquisition process.

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