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Overview of Ceramic Interconnect Technolgy
Published in Fred D. Barlow, Aicha Elshabini, Ceramic Interconnect Technology Handbook, 2018
Aicha Elshabini, Gangqiang Wang, Dan Amey
This process begins with sputtering a thin seed layer, e.g., Ti/Cu/Ti (500/1000/500 Å), providing adhesion/barrier between the dielectric and the metal, as well as an electrode for subsequent electroplating. Titanium on top of copper also protects the copper from oxidation during processes before electroplating. A photoresist layer is then applied onto the dielectric, patterned, and developed to expose areas where copper will be plated, i.e., vias and/or interconnects. Just before to electroplating the copper, the top titanium layer is wet-etched in a solution such as 2% hydrofluoric and 0.5% nitric solution with etching rate of 500–2000 Å/min, depending upon oxidation of the titanium. A 2~10 μm thick copper film is electroplated in the openings for vias and interconnects that were formed in the photoresist layer. Afterward, the photoresist layer is stripped off and the Ti/Cu/Ti seed layer is etched away using the electroplated copper as a mask. Because the copper thickness in the seed layer is only 1000 Å, the etching of the thicker electroplated copper mask is negligible. Whereas titanium is etched in the aforementioned solution, the copper etching may be performed in a solution comprising 1% sulfuric acid and 0.5% hydrogen peroxide.
In Vivo Assessment
Published in Karen J.L. Burg, Didier Dréau, Timothy Burg, Engineering 3D Tissue Test Systems, 2017
Maria Yanez, Scott Collins, Thomas Boland
The animals were subjected multiple biopsies in order to analyze graft integration with the host as well as inflammation. The thickness of the implanted gels was evaluated at the time of the implantation, and then it was compared with the thickness of the different biopsies to assess the thick gel degradation. Figure 5.1 illustrations an implanted scaffold. The white square depicts the adhesion barrier (5 mm larger than the adipose tissue graft). The red box denotes the adipose tissue-engineered graft centered on the barrier with approximate dimensions of 1 cm × 1 cm. Sutures were paced at the four corners through the barrier and skin. The circles labeled 1–4 represent the biopsy sites and the chronological order in which they were taken. Biopsies were done using a 3 mm sterile biopsy punch at each corner of the adipose graft. The biopsies penetrated down through the skin and fascia but not into the muscular layer. Biopsies were taken at days 1, 3, 7, and 14 following the graft implant. The mice were placed under general inhalant (isoflurane) anesthesia for the biopsy and a single 4-0 monofilament suture was placed to close the biopsy defect. The mice were recovered and monitored postbiopsy until they were in sternal recumbency and ambulating normally to ensure no additional pain/distressed was observed. Additional analgesic was administered if the animal exhibited signs of pain/distressed.
Hyaluronic Acid–Based Hydrogel as a Scaffold for Tissue Engineering
Published in Gilson Khang, Handbook of Intelligent Scaffolds for Tissue Engineering and Regenerative Medicine, 2017
Recently HA hydrogels with EDC and ADH crosslinking have been prepared with some defined mesh sizes from high molecular weight HA for tests of its adhesion and proliferation of lung carcinoma cell line H460M41 and adhesion barrier with antiadhesion drugs such as glucocorticoid receptor agonist budesonide within the abdominopelvic cavity following surgery or other injuries.42 While the defect sites either with or without hydrogel addition demonstrated large amount of adhesion, the site treated with budesonide-containing hydrogel demonstrated significant in vivo reduction of both adhesion and inflammation, indicating prevention of postsurgical adhesion and effectiveness of barrier devices by drug delivery. This HA hydrogel was prepared by employing both HA-ADH and HA-aldehyde (Fig. 10.4, 4.1.2-D). While the HA-ADH was obtained by conjugating ADH to carboxylic groups of HA, HA-aldehyde (HA-CHO) was done by reacting HA with sodium periodate. This anti-inflammatory function of HA was also studied by grafting dexamethasone to HA-ADH via succinate chemistry.43 Another example of HA hydrogels via ADH was performed by grafting of HA-ADH with bioactive molecules such as biotin to functionalize and pattern.44
Multi-layer PDMS films having antifouling property for biomedical applications
Published in Journal of Biomaterials Science, Polymer Edition, 2020
M. Mousavi, H. Ghaleh, K. Jalili, F. Abbasi
In this work, the roller casting multi-layer method was employed as an effort to improve the mechanical properties and non-hermeticity of PDMS substrates as packaging for implantable devices. The mechanical measurements showed that with increasing the number of coating layers, the mechanical properties of the tri-layer coatings increased 26 and 54% in proportion to the double-layer coatings and single-layer coatings, respectively. Also, according to the results of the gas permeability tests, it was observed that the rate of oxygen and nitrogen gas flow in the tri-layer PDMS films decreased 46.7 and 63.1%, respectively, in comparison to the single-layer substrate, which has found to be evidence of non-hermetic packaging. Therefore, the roller casting multi-layer method appears to be a suitable technique for packaging micro-devices for fundamental medical research. In addition, due to inherent hydrophobicity and biofouling tendency of PDMS, well-defined and high-density hydrophilic polymer brushes were grafted via SI-ATRP on the PDMS substrates providing an effective enthalpic and entropic barrier against non-specific protein adsorption and cell adhesion. The results of water contact angle measurements demonstrated that the formation of POEGMA brushes significantly improved the hydrophilicity of PDMS surface. In addition to the inherent biocompatibility of the PDMS substrates, POEGMA tethered multi-layer PDMS substrate is potentially useful to fabricate antifouling surfaces and adhesion barrier for application in biomedical devices.
Dual-functional anti-adhesion barrier prepared using micro-hierarchical structured and neutralized shellac films for drug release
Published in Journal of Biomaterials Science, Polymer Edition, 2020
The anti-adhesion barrier requires optimal toughness, or recovery, for application to surgical sites of different shapes such as curves, angles, and waves. The recovery of shellac films in response to bending stress was measured across a range of shellac concentrations, and the results indicated that the recovery of the films increased with increasing shellac concentration. The optimal recovery efficiency was observed at shellac concentrations of over 15%, whereas films with 1% and 5% shellac were easily broken after bending once (Table 1). Therefore, we concluded that the improved recovery was due to the resin concentration. Accordingly, 15% shellac was determined to be the film concentration with optimal physical properties and was used in subsequent tests.
Anticorrosive effectiveness of coatings with reduced content of Zn pigments in comparison with zinc-rich primers
Published in Corrosion Engineering, Science and Technology, 2019
Ewa Langer, Małgorzata Zubielewicz, Helena Kuczyńska, Agnieszka Królikowska, Leszek Komorowski
Investigations of the coatings’ behaviour under corrosive conditions were carried out in a salt chamber (type BS1, Breive) acc. to EN ISO 9227 [47]. The coatings were evaluated after 500, 1000 and 1500 h of salt spray test in terms of corrosion visible on the coating and on the substrate (the corrosion evaluation was performed on a scale from 0 – no damage to 5 – the most damage), adhesion, barrier properties and cathodic protection capacity using the EIS method and measurement of open circuit potential.