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Article
Publication date: 1 December 2003

Liyu Yang, Carl K. King and Joseph B. Bernstein

Liquid encapsulation techniques have been used extensively in advanced semiconductor packaging, including applications of underfilling, cavity‐filling, and glob top…

Abstract

Liquid encapsulation techniques have been used extensively in advanced semiconductor packaging, including applications of underfilling, cavity‐filling, and glob top encapsulation. Because of the advanced encapsulation materials and the automatic liquid dispensing equipment involved, it is very important to understand the encapsulation material characteristics, equipment characteristics, encapsulation process development techniques in order to achieve the encapsulation quality and reliability. In this paper, the authors will examine the various considerations in liquid encapsulation applications and address the concerns on material characterization, automatic liquid dispensing equipment/process characterization and the encapsulation quality and reliability. The discussions will be helpful for future material and process development of semiconductor packages.

Details

Microelectronics International, vol. 20 no. 3
Type: Research Article
ISSN: 1356-5362

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Article
Publication date: 9 December 2020

Anshu Sharma, Anju Kumari Dhiman and Surekha Attri

This study aims to encapsulate the crude carotene pigment isolated from waste portion of Cucurbita maxima with the help of different encapsulating agents through…

Abstract

Purpose

This study aims to encapsulate the crude carotene pigment isolated from waste portion of Cucurbita maxima with the help of different encapsulating agents through lyophilization to transform crude pigment into stable form for further utilization.

Design/methodology/approach

This paper opted for encapsulation of extracted carotene pigment by lyophilization using various carrier materials such as maltodextrin 20 dextrose equivalent (DE), maltodextrin 10 DE and tapioca starch along with emulsifier polysorbate-80. After encapsulation of crude carotene pigment, prepared encapsulated powder was subjected to chemical analysis. The data was analysed statistically by a complete randomized design.

Findings

Maximum encapsulation efficiency, carotene content, antioxidant activity and water solubility index were achieved when 0.06% of crude carotene pigment was emulsified with same quantity of polysorbate-80, followed by encapsulation with 20% of maltodextrin 20 DE during lyophilization.

Originality/value

Even though few researchers have worked on the encapsulation of colour pigments, no researcher has reported encapsulation of carotene pigment extracted from waste of C. maxima.

Details

Pigment & Resin Technology, vol. 50 no. 6
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 1 August 2001

Zhaowei Zhong

Flip chips were assembled on to ceramic boards using eutectic tin‐lead solder with underfill and with/without encapsulation for temperature cycling and…

Abstract

Flip chips were assembled on to ceramic boards using eutectic tin‐lead solder with underfill and with/without encapsulation for temperature cycling and high‐temperature‐high‐humidity tests. After 1.5 years of testing, the reliability performance of the flip chip on board (FCOB) assemblies was compared. All of the FCOB assemblies with underfill, but without encapsulation, survived 5,778 cycles of the temperature cycling test following 5,005 hours of the high‐temperature and high‐humidity test. The results show that encapsulation may not necessarily enhance the reliability of flip chip assemblies and might therefore be omitted.

Details

Soldering & Surface Mount Technology, vol. 13 no. 2
Type: Research Article
ISSN: 0954-0911

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Article
Publication date: 12 January 2010

O.A. Hakeim, Qinguo Fan and Yong K. Kim

The purpose of this paper is to encapsulate aqueous dispersions of nano‐scale CI Pigment Red 122 prepared through ball milling into UV‐curable resins, 1,6 hexanediol…

Abstract

Purpose

The purpose of this paper is to encapsulate aqueous dispersions of nano‐scale CI Pigment Red 122 prepared through ball milling into UV‐curable resins, 1,6 hexanediol diacrylate (HDDA, monomer), and polyester acrylate (oligomer) using the mini‐emulsion technique.

Design/methodology/approach

The encapsulation of pigment is achieved by mixing a surfactant‐stabilised pigment dispersions and a monomer/oligomer mini‐emulsions and subjecting both to mini‐emulsification conditions. A film of encapsulated pigment mini‐emulsion is finally UV cured using water‐soluble initiator. Efficient encapsulation is proven by ultra‐centrifugal sedimentation, scanning electron microscopy and thermogravimetric analysis (TGA). The stability of pigment dispersions and also the encapsulation process are investigated.

Findings

TGA and ultracentrifuge sedimentation results showed that CI Pigment Red 122 is successfully encapsulated into polyester acrylate/HDDA resins. The oligomer (polyester acrylate) in the presence of organic pigment could stabilise the mini‐emulsion droplets without introducing any other hydrophobes (co‐stabiliser) in the formulation. In addition, the encapsulation percentage and suspension stability of mini‐emulsion are best when the polyester acrylate/HDDA weight ratio is 3:2.

Research limitations/implications

The UV‐curable resins used in the present context are 1,6 HDDA and polyester acrylate. Besides, various oligomer/monomer composition types could be used and its impact on encapsulation efficiency could be also studied.

Practical implications

This method of encapsulation is practically effective for modification of organic pigments for use in UV‐curable ink‐jet printing inks.

Originality/value

The developed method is novel from a literature point of view and can be of a great benefit to achieve the required properties of pigmented UV‐curable system in inkjet printing of textiles. In addition, it could find numerous applications in surface coating.

Details

Pigment & Resin Technology, vol. 39 no. 1
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 2 May 2017

Zhiling Ma, Yanjun Qiao, Fei Xie, Xianling Wang and Jing Wang

The purpose of this paper is to evaluate the role of encapsulation temperature on the preparation of silica-encapsulated waterborne aluminium pigments.

Abstract

Purpose

The purpose of this paper is to evaluate the role of encapsulation temperature on the preparation of silica-encapsulated waterborne aluminium pigments.

Design/methodology/approach

The waterborne aluminium pigments were prepared with H2O2 as anchoring agent and siloxane used as precursors in pH = 9.0 medium at different temperatures. The anchorage and compactness of silicon which on aluminium surface were characterized by optical microscopy, scanning electron microscopy and N2 adsorption-desorption. The anticorrosion property was characterized by the volume of produced hydrogen as a function of time.

Findings

The effect of encapsulation temperature on anticorrosion property of aluminium pigments is reflected from the anchorage and the compactness of silica on aluminium surface. Furthermore, when encapsulation temperature is 45-50°C, the silica platelets uniformly anchored on the aluminium surface as a dense film, which show the best anticorrosion property. Lower and higher encapsulation temperatures cause the silica platelets to agglomerate rather than anchor on the aluminium surface, which is unfavourable for the anchorage and the formation of compact silica film. The use of product in waterborne coatings gives a higher glossiness than that of raw material.

Research limitations/implications

Only pH = 9.0 medium was explored, and the other pH medium could result in different optimum temperatures.

Practical implications

The investigation results provide theoretical basis for obtaining excellent waterborne aluminium pigments.

Originality/value

The method of investigating corrosion resistance mechanism of aluminium pigments based on anchorage and compactness is novel.

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Article
Publication date: 4 August 2014

Aneta Arazna, Grażyna Kozioł, Konrad Futera, Kamil Janeczek and Krzysztof Lipiec

– The purpose of this paper was to determine the influence of thermal aging on the stability of organic light-emitting diode (OLED) glass samples made in ambient condition.

Abstract

Purpose

The purpose of this paper was to determine the influence of thermal aging on the stability of organic light-emitting diode (OLED) glass samples made in ambient condition.

Design/methodology/approach

The samples with yellow emitting layer (named as ADS5) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) hole transport layer were examined. Some of the devices were ultraviolet-curable epoxy encapsulation directly after performance. All samples were thermally annealed at 70°C for 1, 2, 3 and 4 hours. The characteristics current–voltage for fresh and aging samples in the range of voltage from 0-15 V were made. The temperature of OLEDs samples in real-time with a thermographic camera was measured too. Additionally, scanning electron microscope image of surface Al cathode immediately after OLED performance and after annealing tests was made.

Findings

The authors stated, that irrespective of the type, the samples were undergoing the degradation. The decrease in value of the current density was registered. That were about 44 per cent and about 24 per cent after thermally annealing the samples with and without encapsulation, respectively (at tension 13 V). Additionally, there were observed massive delamination of the metal cathode.

Originality/value

Influence of thermal annealing and encapsulation on the dynamic characteristics of the OLED devices fabricated in ambient condition was analyzed. There are not many papers in the literature describing examinations of OLED samples which were made in environmental conditions.

Details

Microelectronics International, vol. 31 no. 3
Type: Research Article
ISSN: 1356-5362

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Article
Publication date: 1 September 2001

Zhaowei Zhong

This paper discusses processes of flip chip on FR‐4 using eutectic solder bumps with possible fewer process steps compared to the full assembly process. Some interesting…

Abstract

This paper discusses processes of flip chip on FR‐4 using eutectic solder bumps with possible fewer process steps compared to the full assembly process. Some interesting results in terms of the reliability performance of flip chip on FR‐4 assemblies using eutectic solder have been obtained after an almost‐one‐year temperature cycling test. The process steps of underfilling and curing of underfill can be omitted when a suitable epoxy is used for encapsulation. When underfill is conducted, encapsulation is not necessarily needed from a reliability point of view.

Details

Circuit World, vol. 27 no. 3
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 26 February 2021

Lun Hao Tung, Fei Chong Ng, Aizat Abas, M.Z. Abdullah, Zambri Samsudin and Mohd Yusuf Tura Ali

This paper aims to determine the optimum set of temperatures through correlation study to attain the most effective capillary flow of underfill in a multi-stack ball grid…

Abstract

Purpose

This paper aims to determine the optimum set of temperatures through correlation study to attain the most effective capillary flow of underfill in a multi-stack ball grid array (BGA) chip device.

Design/methodology/approach

Finite volume method is implemented in the simulation. A three-layer multi-stack BGA is modeled to simulate the underfill flow. The simulated models were well validated with the previous experimental work on underfill process.

Findings

The completion filling time shows high regression R-squared value of up to 0.9918, which indicates a substantial acceleration on the underfill process because of incorporation of thermal delta. An introduction of 11 °C thermal delta to the multi-stacks BGA managed to reduce the filling time by up to 16.4%.

Practical implications

Temperature-induced capillary flow is a relatively new type of driven underfill designed specifically for package on package BGA components. Its simple implementation can further improve the productivity of existing underfill process in the industry that is desirable in reducing the process lead time.

Originality/value

The effect of temperature-induced capillary flow in underfill encapsulation on multi-stacks BGA by means of statistical correlation study is a relatively new topic, which has never been reported in any other research according to the authors’ knowledge.

Details

Microelectronics International, vol. 38 no. 2
Type: Research Article
ISSN: 1356-5362

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Article
Publication date: 4 January 2021

Yuxue Jin, Jie Geng, Zhiyi He, Chuan Lv and Tingdi Zhao

Virtual maintenance simulation is of great importance to help designers find and avoid design problems. During its simulation phase, besides the high precision…

Abstract

Purpose

Virtual maintenance simulation is of great importance to help designers find and avoid design problems. During its simulation phase, besides the high precision requirement, collision detection must be suitable for all irregular objects in a virtual maintenance environment. Therefore, in this paper, a collision detection approach is proposed based on encapsulation for irregular objects in the virtual maintenance environment.

Design/methodology/approach

First, virtual maintenance simulation characteristics and several commonly used bounding boxes methods are analyzed, which motivates the application of encapsulation theory. Based on these, three different encapsulation methods are oriented to the needs of simulation, including encapsulation of rigid maintenance objects, flexible maintenance objects and maintenance personnel. In addition, to detecting collisions accurately, this paper divides the detection process into two stages. That is, in the first stage, a rough detection is carried out and then a tiny slice space is constructed to generate corresponding capsule groups, which will be redetected in the secondary stage. At last, several case studies are applied to illustrate the performance of the methodology.

Findings

The automatic construction algorithm for bounding boxes can be adapted to all forms of objects. The number of detection primitives are greatly reduced. It introduces the reachable space of the human body in maintainability as the collision search area.

Originality/value

The advantages of virtual maintenance simulation could also be advantageous in the industry with further studies. The paper believes this study is of particular interest to the readers of your journal.

Details

Assembly Automation, vol. 41 no. 1
Type: Research Article
ISSN: 0144-5154

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Article
Publication date: 8 May 2018

Zhiling Ma, Yajing Wen, Chunyan Zhang and Jing Wang

The purpose of this study is to evaluate the role of encapsulation pH and iron source on the anchorage mode and performance of iron oxide-encapsulated aluminium pigments.

Abstract

Purpose

The purpose of this study is to evaluate the role of encapsulation pH and iron source on the anchorage mode and performance of iron oxide-encapsulated aluminium pigments.

Design/methodology/approach

The coloured waterborne aluminium pigments were prepared at pH 5-7.5 by using FeSO4 and FeCl3 as iron source. The anchorage mode of iron oxides on aluminium was characterized using optical microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction. Furthermore, the pigmentary performance was characterized through anticorrosion test and multi-angle spectroscopy.

Findings

Diaspore and boehmite could form from H2O2 oxidizing aluminium. Both low pH and FeSO4 systems are beneficial for diaspore, inducing green rust anchor on the aluminium to form goethite. Either in FeSO4 or FeCl3 system, slightly high pH is beneficial for the formation of boehmite, which occurred together with ferrihydrite to form denser coating with yellowness and excellent anticorrosion property. At pH above 7, the formation of dendritic iron oxide is detrimental to the anticorrosion property and the glossiness.

Research limitations/implications

Only FeSO4·7H2O and FeCl3·6H2O as iron sources were explored.

Practical implications

The investigation results provide theoretical basis to obtain excellent chromatic waterborne aluminium pigments.

Originality/value

The method for investigation of encapsulation mechanism by surveying the structure of iron oxides on aluminium, which varies with the pH of the system and iron sources, is novel.

Details

Pigment & Resin Technology, vol. 47 no. 3
Type: Research Article
ISSN: 0369-9420

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