scholarly journals Study of the Impact of Curing Condition on Flexural Strength of a Very Thin Semiconductor Package

Author(s):  
Jefferson Talledo

Thinner semiconductor package is becoming popular especially in consumer electronics applications. As package becomes thinner, it is more vulnerable to package crack when subjected to external load. It is important to ensure that the package is strong enough to resist package cracking. This paper presents the study of package flexural strength under different epoxy mold compound curing condition. A 3-point bend test was done to characterize the breaking strength of the package that was subjected to post-mold curing. It was then compared to the strength of the package not subjected to post-mold curing (PMC). Results of the bend testing showed that the package flexural strength is much lower when the package is not subjected to post-mold curing. This study demonstrates that the measurement of flexural strength can be used to determine if the package has undergone post-mold curing or not. Performing the right post-mold curing of the thin molded package is required to ensure higher flexural strength.

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
YanJie Guo ◽  
Fei Lu ◽  
Lei Zhang ◽  
HeLei Dong ◽  
QiuLin Tan ◽  
...  

In order to identify suitable substrate materials for sue in high-temperature pressure sensors that can operate above 1000°C, the high-temperature properties of four high-performance ceramics (99% pure Al2O3 (99Al2O3), 97% pure Al2O3 (97Al2O3), sapphire, and ZrO2) were investigated. Three-point bend testing was used to measure the flexural strengths and flexural moduli of these ceramics, and transient laser emission was used to measure their thermal conductivities. The samples were prepared by hot-press sintering: plates with the dimensions of 3.5 × 5 × 50 mm3 for the bend testing and rods of φ12.5 × 1.5 mm3 for the thermal conductivity measurements. Curves showing the dependence of flexural strength, flexural modulus, and thermal conductivity on temperature were obtained. The results show that the flexural strength and thermal conductivity of sapphire are much greater than those of the other ceramics tested. Thus, we conclude that sapphire is the most appropriate of these materials for use in high-temperature pressure sensors for operation at up to 1000°C.


Author(s):  
Jefferson Talledo

Die fracture strength measurement is important to assess the robustness of a specific silicon die such that it is strong enough to resist die crack. There are several methods used to measure the strength of silicon die and 3-point bend test is the most common. However, the impact of the loading anvil shape on die strength results needs to be investigated. This paper discusses the comparison of die strength characterization using different loading anvil shapes in a 3-point bend test. The anvil shapes considered were wedge shape and needle shape. Die strength calculations were all done using the standard 3-point bend formula for flexural stress. Statistical analysis of the results revealed that die strength measured using wedge shape loading anvil is not significantly different from the strength measured using the needle shape loading anvil. Therefore, using the needle shape loading anvil in a 3-point bend test could still provide die strength results comparable with the results using the standard wedge shape loading anvil.


2007 ◽  
Vol 361-363 ◽  
pp. 873-876 ◽  
Author(s):  
Leif Hermansson ◽  
Lars Kraft ◽  
Karin Lindqvist ◽  
Nils Otto Ahnfelt ◽  
Hakan Engqvist

Flexural strength of a dental material reflects its ability to withstand tensile stresses and thus the fracture risk of a filling. The flexural strength of an experimental bioceramic Calcium aluminate-based (CA) dental restorative material was measured using three different methods with a composite (Tetric Ceram), a glass ionomer cement (Fuji II) and a phosphate cement (Harward) as references. The three test methods were: a) ISO 4049 for dental composites, 3-point bend test b) EN 843-1 for ceramic materials, 3-point bend test and c) ASTM F-394, biaxial ball-on-disc for ceramic materials. The strength of the CA-material, tested in the ball-on-disc method, is close to the theoretical strength based on the microstructure of the material (max. grain size of 15 μm). The composite material and the phosphate cement were rather insensitive to the test method, while the glass ionomer cement as the CA-material showed sensitivity towards the test method. A modified biaxial test method for evaluation of strength of dental materials in a close to real-life component is proposed.


2016 ◽  
Vol 827 ◽  
pp. 211-214
Author(s):  
Tomáš Bittner ◽  
Jindřich Čech ◽  
Petr Bouška ◽  
Miroslav Vokáč ◽  
Šárka Nenadálová

The contribution is focused on research results of thin elements with UHPC matrix reinforced by textile glass reinforcement. A set of three test samples with size of 1100 x 120 x 20 mm were produced in laboratories of the Klokner Institute. Using accompanying tests the material characteristics of the concrete matrix and the textile glass reinforcement were determined. This reinforcement is modified by a protective epoxy surface layer, co called coating. The reason of the coating is to prevent a formation and a development of corrosive processes on the reinforcement texture. The samples were tested at four-point bend test in a thermal chamber. The thermal chamber is a space where it is possible to gradually regulate the temperature up to 75 °C under a constant value of a loading. In the course of the temperature increasing is using a measuring unit measured mainly bend in the middle of the span in time and the course of an inner and outer temperature. The impact of the increased temperature on the cohesiveness of the non-conventional reinforcement and the UHPC matrix is evaluated from the monitored data.


2015 ◽  
Vol 29 (4) ◽  
pp. 135-146 ◽  
Author(s):  
Miroslaw Wyczesany ◽  
Szczepan J. Grzybowski ◽  
Jan Kaiser

Abstract. In the study, the neural basis of emotional reactivity was investigated. Reactivity was operationalized as the impact of emotional pictures on the self-reported ongoing affective state. It was used to divide the subjects into high- and low-responders groups. Independent sources of brain activity were identified, localized with the DIPFIT method, and clustered across subjects to analyse the visual evoked potentials to affective pictures. Four of the identified clusters revealed effects of reactivity. The earliest two started about 120 ms from the stimulus onset and were located in the occipital lobe and the right temporoparietal junction. Another two with a latency of 200 ms were found in the orbitofrontal and the right dorsolateral cortices. Additionally, differences in pre-stimulus alpha level over the visual cortex were observed between the groups. The attentional modulation of perceptual processes is proposed as an early source of emotional reactivity, which forms an automatic mechanism of affective control. The role of top-down processes in affective appraisal and, finally, the experience of ongoing emotional states is also discussed.


2019 ◽  
Vol 10 (12) ◽  
pp. 1183-1199
Author(s):  
Mohammed Alrouili ◽  

This study attempted to identify the impact of internal work environment on the retention of healthcare providers at Turaif General Hospital in the Kingdom of Saudi Arabia. In particular, the study aimed to identify the dimensions of work circumstances, compensation, and relationship with colleagues, professional growth, and the level of healthcare providers’ retention. In order to achieve the study goals, the researcher used the descriptive analytical approach. The researcher used the questionnaire as the study tool. The study population comprised all the healthcare providers at Turaif General Hospital. Questionnaires were distributed to the entire study sample that consisted of 220 individuals. The number of questionnaires valid for study was 183 questionnaires. The research findings were as follows: the participants’ estimate of the work circumstances dimension was high (3.64), the participants’ estimate of the compensation dimension was moderate (3.32), the participants’ estimate of the relationship with colleagues dimension was high (3.62), the participants’ estimate of the professional growth dimension was weak (2.39), and the participants’ estimate of healthcare providers’ retention level was intermediate (2.75). Accordingly, the researcher’s major recommendations are: the need to create the right atmosphere for personnel in hospitals, the interest of the hospital to provide the appropriate conditions for the staff in terms of the physical and moral aspects for building the work adjustment in the staff, and conducting training courses and educational lectures for personnel in hospitals on how to cope with the work pressures.


2017 ◽  
Vol 30 (1) ◽  
pp. 112-121
Author(s):  
Shamier Ebrahim

The right to adequate housing is a constitutional imperative which is contained in section 26 of the Constitution. The state is tasked with the progressive realisation of this right. The allocation of housing has been plagued with challenges which impact negatively on the allocation process. This note analyses Ekurhuleni Metropolitan Municipality v Various Occupiers, Eden Park Extension 51 which dealt with a situation where one of the main reasons provided by the Supreme Court of Appeal for refusing the eviction order was because the appellants subjected the unlawful occupiers to defective waiting lists and failed to engage with the community regarding the compilation of the lists and the criteria used to identify beneficiaries. This case brings to the fore the importance of a coherent (reasonable) waiting list in eviction proceedings. This note further analyses the impact of the waiting list system in eviction proceedings and makes recommendations regarding what would constitute a coherent (reasonable) waiting list for the purpose of section 26(2) of the Constitution.


2019 ◽  
pp. 247-284
Author(s):  
م.د.فاتن محمد رزاق

The concept of tolerance is gaining its importance in the midst of an international society suffering from violence, wars and internal and international crises. It is practiced by extremist and extremist forces and movements acting in the name of religion to exclude the different Muslim and non-Muslim people according to the unethical practices and methodologies of Islamic law and reality. , Cultural, civilization .. that distinguish our world today. The society today is suffering from the ideas of the intellectual and aesthetic views of the different ideologically, ethnically, culturally and religiously in the world of the South. This is what the end-of-history thesis of Fukuyama and the clash of civilizations represented to Huntington. Therefore, it is necessary to confront these extremist and extremist ideas and behaviors. Peace, security and freedom in the international community of justice and equality, needs to be addressed intellectual, cultural, moral and political before they are legal, these treatments are based on dialogue and cooperation and trust and respect and mutual recognition and tolerance so we find the importance of tolerance to The international community is concerned about the need for mechanisms that confront terrorism and violence with an ideology based on respect for the right of diversity, diversity and pluralism. Accordingly, tolerance is a political, cultural and moral necessity based on international legal foundations represented by the United Nations. Through its conferences, declarations and international resolutions issued by it and its specialized agencies, culminating in the Universal Declaration of Tolerance and the International Day of International Peace, and the political foundations represented by democracy and global citizenship that respects all identities and seeks to respect the rights of other identities under the umbrella of international identity Nsanhuahdh respects everyone, a society with a humanitarian goal of a global civil and Ahdlaaaraf borders and the identity of certain Qomahdolh, cultural and educational foundations through plans and programs with educational encourage a spirit of tolerance and world peace. The study was divided into three topics: the first dealt with the concept of tolerance and world peace, and the second topic dealt with the impact of international law and citizenship. In the promotion of world peace "as one of the elements of global tolerance. The last topic included" the role of democracy and education education "in the promotion of world peace and concluded the study by conclusion.


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