Copper Wirebond Compatibility with Organic and Inorganic Ions Present in Mold Compounds

2013 ◽  
Vol 2013 (1) ◽  
pp. 000089-000093
Author(s):  
Varughese Mathew ◽  
Sheila Chopin ◽  
Leo Higgins ◽  
Yingrui Zhang
Keyword(s):  
Inorganic Ions ◽  
Gold Wire ◽  
Chemical Components ◽  
Simple Method ◽  
Inorganic Species ◽  
Ph Conditions ◽  
Ionic Impurities ◽  
Compound Matrix ◽  
The Impact

Copper wirebond (CuWB) packaging is emerging as a replacement to gold wire technology because of the increases in the price of gold. However, copper is more susceptible to corrosion than inert gold so there are several reliability concerns regarding the integrity of the Cu-Al interface. Copper wirebond compatibility with the surrounding encapsulating mold compound is critical as this material combination can produce a corrosive environment in the presence of moisture and ionic impurities. Mold compounds consist of different chemical components that can yield several ionic organic and inorganic species. The effect of chloride on CuWB reliability has been published in the literature, the impact of other ions typically present in mold compound matrix is not widely discussed. It is important to understand the role of these ions on the CuWB reliability to design appropriate mold compounds for product encapsulation as some of the ions are corrosive while others are of benign or beneficial in nature. This paper examines the impact of organic anions such as formate, acetate and oxalate and inorganic anions phosphate and nitrites on CuWB reliability with regards to the integrity of the vulnerable Cu-Al interface. Corrosion depends on the pH conditions of the mold compound matrix in presence of moisture.Cu-Al integrity under various pH conditions and ionic concentrations will be presented and the effect of these ions on the corrosive behavior of chloride will be examined. The combined influences of different anions on the Cu-Al integrity will be discussed. Finally, a relatively simple method to examine the integrity of the Cu-Al interface will also be described.

Copper Wirebond Compatibility with Organic and Inorganic Ions Present in Mold Compounds

2014 ◽  
Vol 11 (2) ◽  
pp. 70-74 ◽  
Author(s):  
Varughese Mathew ◽  
Sheila Chopin ◽  
Leo Higgins ◽  
Yingrui Zhang
Keyword(s):  
Inorganic Ions ◽  
Gold Wire ◽  
Chemical Components ◽  
Simple Method ◽  
Inorganic Species ◽  
Ph Conditions ◽  
Ionic Impurities ◽  
Compound Matrix ◽  
The Impact

Copper wirebond (CuWB) packaging is emerging as a replacement to gold wire technology because of the increases in the price of gold. However, copper is more susceptible to corrosion than inert gold so there are several reliability concerns regarding the integrity of the Cu-Al interface. Copper wirebond compatibility with the surrounding encapsulating mold compound is critical, as this material combination can produce a corrosive environment in the presence of moisture and ionic impurities. Mold compounds consist of different chemical components that can yield several ionic organic and inorganic species. The effect of chloride on CuWB reliability has been published in the literature but the impact of other ions typically present in the mold compound matrix is not widely discussed. It is important to understand the role of these ions on the CuWB reliability to design appropriate mold compounds for product encapsulation as some of the ions are corrosive while others are benign or beneficial in nature. This paper examines the impact of organic anions such as formate, acetate, and oxalate, and inorganic anions phosphate and nitrites, on CuWB reliability with regard to the integrity of the vulnerable Cu-Al interface. Corrosion depends on the pH conditions of the mold compound matrix in the presence of moisture. Cu-Al integrity under various ionic concentrations and pH conditions will be presented and the effect of these ions on the corrosive behavior of chloride will be examined. The combined influences of different anions on the Cu-Al integrity will be discussed. Finally, a relatively simple method to examine the integrity of the Cu-Al interface will also be described.

scholarly journals Long-Range Transport Influence on Key Chemical Components of PM2.5 in the Seoul Metropolitan Area, South Korea, during the Years 2012–2016

Atmosphere ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 48 ◽  
Author(s):  
Changhan Bae ◽  
Byeong-Uk Kim ◽  
Hyun Cheol Kim ◽  
Chul Yoo ◽  
Soontae Kim
Keyword(s):  
Long Range ◽  
Metropolitan Area ◽  
Inorganic Ions ◽  
Long Range Transport ◽  
Chemical Components ◽  
Component Ratio ◽  
Seoul Metropolitan Area ◽  
Range Transport ◽  
The Impact ◽  
Pm2.5 Concentration

This study identified the key chemical components based on an analysis of the seasonal variations of ground level PM2.5 concentrations and its major chemical constituents (sulfate, nitrate, ammonium, organic carbon, and elemental carbon) in the Seoul Metropolitan Area (SMA), over a period of five years, ranging from 2012 to 2016. It was found that the mean PM2.5 concentration in the SMA was 33.7 μg/m3, while inorganic ions accounted for 53% of the total mass concentration. The component ratio of inorganic ions increased by up to 61%–63% as the daily mean PM2.5 concentration increased. In spring, nitrate was the dominant component of PM2.5, accounting for 17%–32% of the monthly mean PM2.5 concentrations. In order to quantify the impact of long-range transport on the SMA PM2.5, a set of sensitivity simulations with the community multiscale air-quality model was performed. Results show that the annual averaged impact of Chinese emissions on SMA PM2.5 concentrations ranged from 41% to 44% during the five years. Chinese emissions’ impact on SMA nitrate ranged from 50% (winter) to 67% (spring). This result exhibits that reductions in SO2 and NOX emissions are crucial to alleviate the PM2.5 concentration. It is expected that NOX emission reduction efforts in China will help decrease PM2.5 concentrations in the SMA.

scholarly journals A Review of Manganese(III) (Oxyhydr)Oxides Use in Advanced Oxidation Processes

Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 5748
Author(s):  
Daqing Jia ◽  
Khalil Hanna ◽  
Gilles Mailhot ◽  
Marcello Brigante
Keyword(s):  
Singlet Oxygen ◽  
Advanced Oxidation Processes ◽  
Inorganic Ions ◽  
Advanced Oxidation ◽  
Solution Ph ◽  
Oxidation Processes ◽  
Treatment Processes ◽  
Activation Mechanisms ◽  
The Impact

The key role of trivalent manganese (Mn(III)) species in promoting sulfate radical-based advanced oxidation processes (SR-AOPs) has recently attracted increasing attention. This review provides a comprehensive summary of Mn(III) (oxyhydr)oxide-based catalysts used to activate peroxymonosulfate (PMS) and peroxydisulfate (PDS) in water. The crystal structures of different Mn(III) (oxyhydr)oxides (such as α-Mn2O3, γ-MnOOH, and Mn3O4) are first introduced. Then the impact of the catalyst structure and composition on the activation mechanisms are discussed, as well as the effects of solution pH and inorganic ions. In the Mn(III) (oxyhydr)oxide activated SR-AOPs systems, the activation mechanisms of PMS and PDS are different. For example, both radical (such as sulfate and hydroxyl radical) and non-radical (singlet oxygen) were generated by Mn(III) (oxyhydr)oxide activated PMS. In comparison, the activation of PDS by α-Mn2O3 and γ-MnOOH preferred to form the singlet oxygen and catalyst surface activated complex to remove the organic pollutants. Finally, research gaps are discussed to suggest future directions in context of applying radical-based advanced oxidation in wastewater treatment processes.

scholarly journals An in vitro investigation of species-dependent intestinal transport of selenium and the impact of this process on selenium bioavailability

2012 ◽  
Vol 109 (12) ◽  
pp. 2126-2134 ◽  
Author(s):  
Celine Thiry ◽  
Ann Ruttens ◽  
Luc Pussemier ◽  
Yves-Jacques Schneider
Keyword(s):  
Human Subjects ◽  
Intestinal Transport ◽  
Inorganic Species ◽  
In Vitro Investigation ◽  
Selenium Bioavailability ◽  
Species Specific ◽  
The Impact ◽  
Paracellular Diffusion

A range of Se species has been shown to occur in a variety of different foodstuffs. Depending on its speciation, Se is more or less bioavailable to human subjects. In the present study, the role of speciation as a determinant of Se bioavailability was addressed with an investigation of species-specific mechanisms of transport at the intestinal level. The present work focused on four distinct Se compounds (selenate (Se(VI)), selenite (Se(IV)), selenomethionine (SeMet) and methylselenocysteine (MeSeCys)), whose intestinal transport was mimicked through an in vitro bicameral model of enterocyte-like differentiated Caco-2 cells. Efficiency of Se absorption was shown to be species dependent (SeMet>MeSeCys>Se(VI)>Se(IV)). In the case of SeMet, MeSeCys and Se(VI), the highly polarised passage from the apical to basolateral pole indicated that a substantial fraction of transport was transcellular, whilst results for Se(IV) indicated paracellular diffusion. Passage of the organic Se species (SeMet and MeSeCys) became saturated after 3 h, but no such effect was observed for the inorganic species. In addition, SeMet and MeSeCys transport was significantly inhibited by their respective S analogues methionine and methylcysteine, which suggests a common transport system for both kinds of compounds.

Intergroup Threat and Outgroup Attitudes

2013 ◽  
Vol 44 (5) ◽  
pp. 311-319 ◽  
Author(s):  
Marco Brambilla ◽  
David A. Butz
Keyword(s):  
Gay Men ◽  
Social Group ◽  
Welfare Recipients ◽  
Intergroup Attitudes ◽  
Social Policies ◽  
Intergroup Threat ◽  
Economic Threat ◽  
The Impact ◽  
General Climate

Two studies examined the impact of macrolevel symbolic threat on intergroup attitudes. In Study 1 (N = 71), participants exposed to a macrosymbolic threat (vs. nonsymbolic threat and neutral topic) reported less support toward social policies concerning gay men, an outgroup whose stereotypes implies a threat to values, but not toward welfare recipients, a social group whose stereotypes do not imply a threat to values. Study 2 (N = 78) showed that, whereas macrolevel symbolic threat led to less favorable attitudes toward gay men, macroeconomic threat led to less favorable attitudes toward Asians, an outgroup whose stereotypes imply an economic threat. These findings are discussed in terms of their implications for understanding the role of a general climate of threat in shaping intergroup attitudes.

Sign in / Sign up

Export Citation Format

Share Document