scholarly journals Package Reliability Performance Study of QFN Device on Different Die Attach Machines

2020 ◽  
pp. 41-43
Author(s):  
Edwin Graycochea Jr. ◽  
Rennier Rodriguez ◽  
Frederick Ray Gomez ◽  
Bryan Christian Bacquian
Keyword(s):  
Thermal Cycling ◽  
Thermal Cycle ◽  
Performance Study ◽  
Die Attach ◽  
Significant Difference ◽  
Quality And Reliability ◽  
The Difference ◽  
Reliability Performance ◽  
Two Machines ◽  
Package Reliability

The paper is focused on the reliability performance of quad-flat no-leads (QFN) package evaluated on different die attach machine platforms. Reliability tests were done to check the difference in the quality and reliability performance of the device that undergone die attach process on two different machines. Thermal cycling resulted in significant difference on the two machines, with the device processed in Machine 1 showing reliability failures while on Machine 2 it passed the 1000 thermal cycle. For future works, Machine 2 could be used for devices with critical package reliability requirement.

Package Reliability of the SiC Power Modules in Harsh Environments

2011 ◽  
Vol 2011 (HITEN) ◽  
pp. 000139-000144
Author(s):  
Fengqun Lang ◽  
Hiroshi Yamaguchi ◽  
Hiroshi Sato
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Electrical Resistivity ◽  
Thermal Cycling ◽  
Isothermal Aging ◽  
Harsh Environments ◽  
Die Attach ◽  
Power Modules ◽  
Almost All ◽  
Package Reliability

To evaluate the package reliability of the SiC power modules in harsh environments, the SiC Schottky Barrier Diodes (SBDs) were die bonded to the Si3N4/Cu/Ni(P) substrate with Au-Ge eutectic solder using a vacuum reflow furnace. The Si3N4/Cu/Ni(P) substrates are active metalized copper (AMC). The bonded samples were isothermally aged at 330°C and tested under thermal cycling conditions in the temperature range of −40–300°C in air. During the isothermal aging, cracks of the Ni(P) layer developed, resulting in oxidation of the Cu power path. Decrease in the die bond strength and increase in the electrical resistivity were observed due to the Cu power path oxidation and the growth of the Ni-Ge intermetalic compound (IMC) in the joint. Under the thermal cycling conditions, the metallization of the substrate suffers from serious surface roughness, which greatly degrades the die-attach reliability. The Al electrode was found to seriously exfoliate from the SiC-SBDs due to the thermal stress. After 521 cycles, almost all the Al electrode exfoliated form the anode. Benefit from the excellent mechanical properties of Si3N4, no detachment of the Cu layer was observed from the Si3N4 substrate after 1079 cycles, while the Cu layer detached from the AlN substrate only after 12 cycles.

scholarly journals Microleakage under ceramic flash-free orthodontic brackets after thermal cycling

2016 ◽  
Vol 86 (6) ◽  
pp. 905-908 ◽  
Author(s):  
Julia Kim ◽  
Georgios Kanavakis ◽  
Matthew D. Finkelman ◽  
Moonyoung Lee
Keyword(s):  
Methylene Blue ◽  
Statistical Analysis ◽  
Thermal Cycling ◽  
Laboratory Setting ◽  
Methylene Blue Solution ◽  
Significant Difference ◽  
Blue Solution ◽  
Maxillary Premolars ◽  
The Difference ◽  
Bracket Base

ABSTRACT Objective: To compare microleakage under 3M Unitek's APC Flash-Free Adhesive Coated System bracket and the APC PLUS Adhesive Coated System bracket after thermal cycling. Materials and Methods: Forty freshly extracted human maxillary premolars were randomly divided into two groups and bonded with either a Flash-Free bracket or a PLUS bracket. After bonding, the samples were incubated in a water bath at 37°C for 24 hours and thermocycled for 5000 cycles between 5°C and 50°C. All teeth were immersed in a 2% methylene blue solution for 24 hours, embedded in acrylic and sectioned in a buccolingual direction at approximately the center of the bracket. Microleakage was observed at the enamel-adhesive interface from the occlusal and gingival margins of the bracket base. Statistical analysis was conducted using the Mann-Whitney U-test. Results: The median microleakage was higher in the Flash-Free group, but the difference between the two groups was not statistically significant (P > .05). Conclusion: In a laboratory setting, there is no significant difference between the extent of microleakage under the APC Flash-Free Adhesive Coated System bracket and the APC PLUS Adhesive Coated System bracket after thermal cycling.

Evaluation of High Temperature Joining Technologies for Semiconductor Die Attach

2017 ◽  
Vol 2017 (HiTEN) ◽  
pp. 000177-000192
Author(s):  
Siyuan Qi ◽  
Chris Powley ◽  
Maria Mirgkizoudi ◽  
Adele Pliscott ◽  
Peter Collier
Keyword(s):  
Shear Strength ◽  
High Temperature ◽  
Thermal Cycling ◽  
Industrial Applications ◽  
Thermal Ageing ◽  
Conductive Adhesives ◽  
Similar Reduction ◽  
Initial Values ◽  
Die Attach ◽  
Reliability Performance

Abstract The development of novel high temperature die attach methods for semiconductor packaging enables use in harsh environments and unique opportunities for demanding industrial applications such as controls and monitoring for next generation engine and airframe platforms. Traditional die attach materials including lead solders and conductive adhesives cannot meet requirements of operation temperatures up to and exceeding 300°C due to their limited melting and glass transition temperatures [1]. The Manufacturing Technology Centre Ltd (MTC) has evaluated a range of high temperature die attach materials and processes for silicon and silicon carbide (SiC) semiconductors. Assembly processes were explored for bonding components with and without a back metallisation and with capability to support electrical back contact if required. Die attach methods evaluated include:Sinterable silver materials for back metallised semiconductor componentsSilver glass for non-back metallised semiconductor componentsGold-silicon near eutectic preforms for non-back metallised semiconductor components Two types of substrates were selected including high temperature co-fired ceramic (HTCC) packages and gold or silver plated Kovar substrates. Test assemblies were subjected to accelerated life tests consisting of thermal ageing at 400°C and thermal cycling of −40°C to 200°C. These tests enabled the evaluation of the die attach materials after accelerated conditions of use. Reliability performance of the die attach materials was assessed using visual and X-ray inspection, mechanical shear testing and microstructure analysis. For sinterable silver materials, the test assemblies constructed using HTCC packages showed no significant reduction in shear strength after 1,008 hours ageing at 400°C. However shear strengths of the test assemblies constructed using Kovar substrates reduced by 95% of the initial values after ageing at 400°C for 336 hours. All test assemblies showed no significant reduction in adhesion after thermal cycling of −40°C to 200°C for 1,000 cycles. In addition, no apparent differences in shear strengths could be detected for sintered silver interconnections for gold and silver metallised semiconductor components. Gold-silicon bonding as performed using a near eutectic preform had limited performance as aged at 400°C. Silver glass test assemblies constructed using HTCC packages showed a 50% reduction in shear strength compared to the initial values after thermal ageing at 400°C for 1,000 hours. A similar reduction in adhesion was presented after thermal cycling of −40°C to 200°C for 1,000 cycles.

scholarly journals Die Attach Process Optimization with Enhanced Epoxy Control on Leadframe Package

2020 ◽  
pp. 32-37
Author(s):  
Rennier S. Rodriguez ◽  
Edwin M. Graycochea Jr ◽  
Rammil A. Seguido ◽  
Frederick Ray I. Gomez
Keyword(s):  
Shear Strength ◽  
Thermal Cycling ◽  
Process Optimization ◽  
Shear Test ◽  
Relative Impact ◽  
Adhesive Material ◽  
Practical Procedure ◽  
Die Attach ◽  
Package Reliability

The paper presents a practical procedure in selecting the best candidate for die attach epoxy control or anti-epoxy bleed-out (anti-EBO) concentration during the introduction of new leadframe configuration. Three different criteria were implemented to measure the relative impact of the anti-EBO into the different interfaces inside a quad-flat no-leads multi-row (QFN-mr) leadframe unit. Die shear test is performed to measure the shear strength and the compatibility of the anti-EBO to the adhesive material. EBO measurement is performed herewith to study the propagation of epoxy bleed-out on the surface of the leadframe with reference to the different level of anti-EBO concentration. Package reliability is employed study the response of different interfaces directly in-contact with anti-EBO through thermal-cycling scenario. Ultimately, understanding the effect of anti-EBO into different set of tests provided a systematic way of selecting appropriate leadframe parameters for QFN-mr leadframe product.

Cranial crassicaudiasis in two coastal dolphin species from South Africa is predominantly a disease of immature individuals

2020 ◽  
Vol 139 ◽  
pp. 93-102 ◽  
Author(s):  
MF Van Bressem ◽  
P Duignan ◽  
JA Raga ◽  
K Van Waerebeek ◽  
N Fraijia-Fernández ◽  
...  
Keyword(s):  
South Africa ◽  
Bone Development ◽  
Bottlenose Dolphins ◽  
Fatal Outcome ◽  
Population Level ◽  
Cape Coast ◽  
Osteolytic Lesions ◽  
Immune Mediated ◽  
Significant Difference ◽  
The Difference

Crassicauda spp. (Nematoda) infest the cranial sinuses of several odontocetes, causing diagnostic trabecular osteolytic lesions. We examined skulls of 77 Indian Ocean humpback dolphins Sousa plumbea and 69 Indo-Pacific bottlenose dolphins Tursiops aduncus, caught in bather-protecting nets off KwaZulu-Natal (KZN) from 1970-2017, and skulls of 6 S. plumbea stranded along the southern Cape coast in South Africa from 1963-2002. Prevalence of cranial crassicaudiasis was evaluated according to sex and cranial maturity. Overall, prevalence in S. plumbea and T. aduncus taken off KZN was 13 and 31.9%, respectively. Parasitosis variably affected 1 or more cranial bones (frontal, pterygoid, maxillary and sphenoid). No significant difference was found by gender for either species, allowing sexes to be pooled. However, there was a significant difference in lesion prevalence by age, with immature T. aduncus 4.6 times more likely affected than adults, while for S. plumbea, the difference was 6.5-fold. As severe osteolytic lesions are unlikely to heal without trace, we propose that infection is more likely to have a fatal outcome for immature dolphins, possibly because of incomplete bone development, lower immune competence in clearing parasites or an over-exuberant inflammatory response in concert with parasitic enzymatic erosion. Cranial osteolysis was not observed in mature males (18 S. plumbea, 21 T. aduncus), suggesting potential cohort-linked immune-mediated resistance to infestation. Crassicauda spp. may play a role in the natural mortality of S. plumbea and T. aduncus, but the pathogenesis and population level impact remain unknown.

Perbedaan Penggunaan Antikoagulan K2EDTA DAN K3EDTA Terhadap Hasil Pemeriksaan Indeks Eritrosit

2018 ◽  
Vol 1 (2) ◽  
pp. 114
Author(s):  
Wahdaniah Wahdaniah ◽  
Sri Tumpuk
Keyword(s):  
Screening Test ◽  
Venous Blood ◽  
The Body ◽  
Ethylene Diamine ◽  
P Value ◽  
Cross Sectional ◽  
Significant Difference ◽  
Ethylene Diamine Tetra Acetate ◽  
The Difference ◽  
Index Value

Abstract: Routine blood examination is the earliest blood test or screening test to determine the diagnosis of an abnormality. Blood easily froze if it is outside the body and can be prevented by the addition of anticoagulants, one of which Ethylene Diamine Tetra Acetate (EDTA). Currently available vacuum tubes containing EDTA anticoagulants in the form of K2EDTA and K3EDTA. K3EDTA is usually a salt that has better stability than other EDTA salts because it shows a pH approaching a blood pH of about 6.4. The purpose of this research is to know the difference of erythrocyte index results include MCH, MCV and MCHC using K3EDTA anticoagulant with K2EDTA. This research is a cross sectional design. This study used venous blood samples mixed with K2EDTA anticoagulant and venous blood mixed with K3EDTA anticoagulants, each of 30 samples. Data were collected and analyzed using paired different test. Based on data analysis that has been done on MCH examination, p value <0,05 then there is a significant difference between samples with K3EDTA anticoagulant with K2EDTA to erythrocyte index value. Then on the examination of MCV and MCHC obtained p value <0.05 then there is no significant difference between samples with K3EDTA anticoagulant with K2EDTA to erythrocyte index value.Abstrak: Pemeriksaan darah rutin merupakan pemeriksaan darah yang paling awal atau screening test untuk mengetahui diagnosis suatu kelainan. Darah mudah membeku jika berada diluar tubuh dan bisa dicegah dengan penambahan antikoagulan, salah satunya Ethylene Diamine Tetra Acetate (EDTA). Dewasa ini telah tersedia tabung vakum yang sudah berisi antikoagulan EDTA dalam bentuk  K2EDTA dan  K3EDTA. K3EDTA  biasanya berupa garam yang mempunyai stabilitas yang lebih baik dari garam EDTA yang lain karena menunjukkan pH yang mendekati pH darah yaitu sekitar 6,4. Tujuan dari penelitian ini adalah untuk mengetahui perbedaan hasil indeks eritrosit meliputi MCH, MCV dan MCHC menggunakan antikoagulan K3EDTA dengan K2EDTA. Penelitian ini merupakan penelitian dengan desain cross sectional. Penelitian ini menggunakan sampel darah vena yang dicampur dengan antikoagulan K2EDTA dan darah vena yang dicampur dengan antikoagulan K3EDTA, masing-masing sebanyak 30 sampel. Data dikumpulkan dan dianalisis menggunakan uji beda berpasangan. Berdasarkan analisis data yang telah dilakukan pada pemeriksaan MCH didapatkan nilai p < 0,05 maka ada perbedaan yang signifikan antara sampel dengan antikoagulan K3EDTA dengan K2EDTA terhadap nilai indeks eritrosit. Kemudian pada pemeriksaan MCV dan MCHC didapatkan nilai p < 0,05 maka tidak ada perbedaan yang signifikan antara sampel dengan antikoagulan K3EDTA dengan K2EDTA terhadap nilai indeks eritrosit.

Pengaruh Jumlah Pencucian Beras dengan Kadar Klorin

2017 ◽  
Vol 1 (1) ◽  
pp. 89
Author(s):  
Indah Purwaningsih ◽  
Supriyanto Supriyanto
Keyword(s):  
Mucous Membrane ◽  
Confidence Level ◽  
Iodometric Titration ◽  
Titration Method ◽  
Anova Test ◽  
Average Value ◽  
Significant Difference ◽  
The Difference

Abstract: Chlorine is a green halogen-shaped halogen gas at normal temperature and serves as bleach, stain remover and disinfectant. Chlorine is now widely used for bleaching rice so that less quality rice looks like quality rice. Chlorine is very toxic and causes mucous membrane irritation, highly reactive and very powerful oxidizer. The purpose of this research was to determine the difference of chlorine level in chlorinated rice washed once, twice and 3 times. The sample in this study amounted to 11 samples calculated by replication formula. Each sample was treated 3 times, ie 1 washed once, 2 washed twice and washed 3 times. The samples then examined by iodometric titration method. Based on the results of the study using ANOVA test, 11 samples obtained the average value of chlorine after washed once amount of 0.0176%, after washed twice amount of 0.0111%, and after washed 3 times amount of 0.0052% with the value significance p = 0.03 (p <0.05) at 95% confidence level which means there was a significant difference between chlorine levels in chlorinated rice washed once, twice and 3 times.Abstrak: Klorin merupakan unsur halogen berbentuk gas berwarna kuning kehijauan pada suhu normal danberfungsi sebagai pemutih, penghilang noda maupun desinfektan. Klorin sekarang banyak digunakan untuk bahan pemutih beras agar beras yang kurang berkualitas tampak seperti beras berkualitas. Klorin sangat toksik dan menyebabkan iritasi membran mukosa, sangat reaktif dan merupakan oksidator yang sangat kuat. Tujuan dari penelitian ini ialah untuk mengetahui perbedaan kadar klorin pada beras berklorin yang dicuci sebanyak 1 kali, 2 kali dan 3 kali. Sampel dalam penelitian ini berjumlah 11 sampel yang dihitung dengan rumus replikasi. Setiap sampel diberi perlakuan sebanyak 3 kali, yaitu 1 kali pencucian, 2 kali pencucian dan 3 kali pencucian. Sampel penelitian kemudian diperiksa dengan metode titrasi iodometri. Berdasarkan hasil penelitian menggunakan uji Anova secara komputerisasi terhadap 11 sampel diperoleh nilai rata-rata kadar klorin setelah 1 kali pencucian sebesar 0,0176 %, setelah 2 kali pencucian sebesar 0,0111 %, dan setelah 3 kali pencucian sebesar 0,0052 % dengan nilai signifkansi p = 0,03 (p<0,05) pada tingkat kepercayaan 95% yang artinya ada perbedaan yang bermakna antara kadar klorin pada beras berklorin yang dicuci sebanyak 1 kali, 2 kali dan 3 kali.

P-Removal in Completely Mixed Systems

1985 ◽  
Vol 17 (11-12) ◽  
pp. 325-326 ◽  
Author(s):  
H J. G. W. Donker ◽  
P. Opic ◽  
H. P. de Vries
Keyword(s):  
Mixed System ◽  
Domestic Waste ◽  
Recirculation Flow ◽  
Start Up ◽  
Significant Difference ◽  
Aerobic Reactor ◽  
The Difference ◽  
Positive Effect ◽  
Mixed Systems ◽  
P Removal

Ca. 60 % of the Dutch activated sludge plants consist of completely mixed systems, experiments have been carried out in completely mixed pilot plants to study the biological P-removal. The research was carried out in two pilot plants. The pilot plants consisted of: anaerobic reactor, anoxic reactor, aerobic reactor and a clarifier. All the reactors were completely mixed. Both plants were fed with settled domestic waste water at a sludge loading of 400 and 250 g COD/kg sludge.day respectively. The results are given below:sludge loading (g COD/kg sludge.day)400400250ratio Anaerobic : Anoxic : Aerobic1: 1:2,71:1:4,11:1:2,7P-removal (%)802875N-removal (%)505065COD-removal (%)858585 It has been shown that there is no significant difference between the results at the two different sludge loadings. Remarkable is the difference between the ratio 1:1:2,7 in combination with the internal recirculation flow anoxic-anaerobic of 160 % and the ratio 1:1:4,1 with a recirculation flow of 30 %. During the start-up at a sludge loading of 250 g COD/kg sludge.day and an internal recirculation flow of 30 %, bulking sludge developed almost immediately. The Premoval was completely disturbed. Increasing the internal recirculation flow to 160% had a positive effect on settling properties and P-removal. This investigation has pointed out that a completely mixed system is suitable for biological P-removal, without negatively affecting the nitrification. Important factors in the process are the ratio anaerobic:anoxic:aerobic and the recirculation flows.

Effect of Levetiracetam on Cognitive Function and Clonic Seizure Frequency in Children with Epilepsy

2019 ◽  
Vol 19 (9) ◽  
pp. 699-703
Author(s):  
Shihao Zhou ◽  
Qiong Zhan ◽  
Xiaomei Wu
Keyword(s):  
Cognitive Function ◽  
Effective Rate ◽  
Clonic Seizure ◽  
Conventional Group ◽  
Significant Difference ◽  
Random Number Table ◽  
Clonic Seizures ◽  
The Difference ◽  
Experimental Group ◽  
Executive Ability

Background: This study aimed to explore the clinical effect of levetiracetam in the treatment of children with epilepsy. Methods: 136 children with epilepsy were selected from January 2017 to December 2017. According to the random number table method, they were divided into the experimental group and the conventional group, with 68 cases in each group. The conventional group was treated with valproate, while the experimental group was treated with levetiracetam. The effective rate, the cognitive function and the frequency of clonic seizures in the two groups were compared. Results: There was no significant difference in the total effective rate between the two groups (P>0.05). There was no significant difference in attention, executive ability, abstract and orientation scores between the two groups before treatment (P>0.05). After treatment, the focus of attention (106.54±6.56), executive ability (105.76±6.77), abstract and directional score (106.65±6.57) were significantly higher than that of the conventional group. The difference in the two groups was statistically significant (P<0.05). After 3 months of treatment, the frequency of myoclonic seizures (9.22±0.95) and the frequency of tonic-clonic seizures (11.68±1.36) were found to be significantly lower than those of the conventional group, and the difference between the two groups was statistically significant (P<0.05). Conclusion: Levetiracetam is effective in the treatment of children with epilepsy. It can effectively improve the cognitive function of the patients, reduce the frequency of myoclonic seizures and tonic-clonic seizures, and has a high promotion value.

Stability and mutual impact of perception of parental pressure and infants' social support – A study based on the difference between employment status and household income

2021 ◽  
pp. 002072092199705
Author(s):  
Yong Wang
Keyword(s):  
Household Income ◽  
Employment Status ◽  
Working Mothers ◽  
Social Research ◽  
Research Report ◽  
Parental Pressure ◽  
Income Levels ◽  
Significant Difference ◽  
The Difference ◽  
The Stability

The purpose of this study is to explore the stability and interaction between parental pressure and social research report, as well as the role of employment status and family income levels in this process. This study used a special study on Korean children (PSKC) 2–4 waves. Use t-test, correlation and autoregressive cross-delay modeling to analyze the data. The main findings of this study are: First, over time, parental pressure and mother’s social research report are consistent. Secondly, the pressure of motherhood and childcare has an obvious lagging effect on upbringing, and vice versa. Third, there is no significant difference between working mothers and non-working mothers in terms of the stability of working parents' pressure, social research report and social research report for children's pressure channels. However, parental pressure can only predict the social research report of working mothers. Fourth, there is no significant difference between the stability and interaction of these two structures in household income levels. In short, the results show that, over time, parental pressure is consistent with mother’s social research report. The results also show that there is a significant cross-lag effect between the mothers’ perceptions of mutual pressure analysis. In the process from parental pressure to social research report, I found the difference between working and non-working mothers. The advantage of this study is that the expected longitudinal design was adopted during infancy and the priority between the two structures can be considered. The results of this study can be used as a source of intervention plans to help parents withstand severe parenting pressure and lack of social research report.

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