Pb-free v/s Tin-Lead Reliability Comparison for Telecom/High Reliability Applications

2010 ◽  
Vol 2010 (1) ◽  
pp. 000284-000293
Author(s):  
Ganesh Iyer ◽  
Gnyaneshwar Ramakrishna ◽  
Lavanya Gopalakrishnan ◽  
Kuo-Chuan Liu
Keyword(s):  
Service Providers ◽  
High Reliability ◽  
Consumer Electronics ◽  
Circuit Board ◽  
Evaluation Methodology ◽  
Mechanical Shock ◽  
Printed Circuit Board Assembly ◽  
Component Level ◽  
Cross Sectional ◽  
Free Solder

With the European Union's (EU's) RoHS directives coming into force in July 2006 for consumer electronics products, the transition to lead-free (Pb-free) solder has occurred at a rapid pace. This push has driven many OEM suppliers/manufacturers to adopt Pb-free solder and End of Life many of their conventional Tin-Lead (Sn-Pb) components. This has forced telecom or high reliability applications to adopt Pb-free solder compositions with many reliability anomalies unanswered. While there have been many studies published on long term reliability of Pb-free solder joints at the component level, there have been few studies focused on the time zero reliability of the joints at the printed circuit board assembly (PCBA) level. The goal of this study is to help the OEM suppliers and their customers (like service providers) to come up with a common PCBA test methodology that will help identify and weed out early, marginal manufacturing and design defects that would crop up due to transition to the Pb-free solder. A normalized reliability data comparison and impact of the test on Pb-free and Tin-Lead solder alloys using test vehicles is presented in this study. The sequential PCBA level evaluation methodology involves a series of tests that include Thermal Aging, Mechanical Shock, Vibration, Functional test over elevated temperature and Destructive Analysis (Dye & Pry and Cross-sectional analysis) . The solder joint reliability comparisons for different components are presented against this methodology using different PCBA constructions (test vehicles).

Effect of Design Parameters on Drop Test Performance of Wafer Level Chip Scale Packages

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
P. Tumne ◽  
V. Venkatadri ◽  
S. Kudtarkar ◽  
M. Delaus ◽  
D. Santos ◽  
...  
Keyword(s):  
Flip Chip ◽  
Consumer Electronics ◽  
Drop Test ◽  
Circuit Board ◽  
Design Parameters ◽  
Mechanical Shock ◽  
Wafer Level ◽  
Cross Sectional ◽  
Right Censored Data ◽  
Solder Balls

Today’s consumer market demands electronics that are smaller, faster, and cheaper. To cater to these demands, novel materials, new designs, and new packaging technologies are introduced frequently. Wafer level chip scale package (WLCSP) is one of the emerging package technologies that have the key advantages of reduced cost and smaller footprint. The portable consumer electronics are frequently dropped; hence, the emphasis of reliability is shifting toward the study of effects of mechanical shock loading increasingly. Mechanical loading typically induces brittle fractures (also known as intermetallic failures) between the solder bumps and the bond pads at the silicon die side. This type of failure mechanism is typically characterized by the board level drop test. WLCSP is a variant of the flip-chip interconnection technique. In WLCSPs, the active side of the die is inverted and connected to the printed circuit board (PCB) by solder balls. The size of these solder balls is typically large enough (300 μm pre-reflow for 0.5-mm pitch and 250 μm pre-reflow for 0.4-mm pitch) to avoid the use of underfill that is required for the flip-chip interconnects. Several variations are incorporated in the package design parameters to meet the performance, reliability, and footprint requirements of the package assembly. The design parameters investigated in this effort are solder ball compositions with different silver (Ag) contents, backside lamination with different thicknesses, WLCSP type—direct and redistribution layer (RDL), bond pad thickness, and sputtered versus electroplated under bump metallurgy (UBM) deposition methods for 8 × 8, 9 × 9, and 10 × 10 array sizes. The test vehicles built using these design parameters were drop tested using Joint Electron Devices Engineering Council (JEDEC) recommended test boards and conditions as per JESD22-B11. Cross-sectional analysis was used to identify, confirm, and segregate the intermetallic and bulk solder failures. The objective of this research was to quantify the effects and interactions of WLCSP design parameters through drop test. The drop test data were collected and treated as a right censored data. Further, it was analyzed by fitting empirical distributions using the grouped and ungrouped data approach. Data analysis showed that design parameters had a significant effect on the drop performance and played a vital role in influencing the package reliability.

Effect of Design Parameters on Drop Test Performance of Wafer Level Chip Scale Packages (WLCSP)

2011 ◽  
Author(s):  
Pushkraj Tumne ◽  
Vikram Venkatadri ◽  
Santosh Kudtarkar ◽  
Michael Delaus ◽  
Daryl Santos ◽  
...  
Keyword(s):  
Flip Chip ◽  
Bulk Solder ◽  
Consumer Electronics ◽  
Drop Test ◽  
Design Parameters ◽  
Mechanical Shock ◽  
Wafer Level ◽  
Cross Sectional ◽  
Right Censored Data ◽  
Solder Balls

Today’s consumer market demands electronics that are smaller, faster and cheaper. To cater to these demands, novel materials, new designs, and new packaging technologies are introduced frequently. Wafer Level Chip Scale Package (WLCSP) is one of the emerging package technologies that have the key advantages of reduced cost and smaller footprint. The portable consumer electronics are frequently dropped; hence the emphasis of reliability is shifting towards study of effects of mechanical shock loading increasingly. Mechanical loading typically induces brittle fractures (also known as intermetallic failures) between the solder bumps and bond pads at the silicon die side. This type of failure mechanism is typically characterized by the board level drop test. WLCSP is a variant of the flip-chip interconnection technique. In WLCSPs, the active side of the die is inverted and connected to the PCB by solder balls. The size of these solder balls is typically large enough (300μm pre-reflow for 0.5mm pitch and 250μm pre-reflow for 0.4mm pitch) to avoid use of underfill that is required for the flip-chip interconnects. Several variations are incorporated in the package design parameters to meet the performance, reliability, and footprint requirements of the package assembly. The design parameters investigated in this effort are solder ball compositions with different Silver (Ag) content, backside lamination with different thickness, WLCSP type –Direct and Re-Distribution Layer (RDL), bond pad thickness, and sputtered versus electroplated Under Bump Metallurgy (UBM) deposition methods for 8×8, 9×9, and 10×10 array sizes. The test vehicles built using these design parameters were drop tested using JEDEC recommended test boards and conditions as per JESD22-B11. Cross sectional analysis was used to identify, confirm, and classify the intermetallic, and bulk solder failures. The objective of this research was to quantify the effects and interactions of WLCSP design parameters through drop test. The drop test data was collected and treated as a right censored data. Further, it was analyzed by fitting empirical distributions using the grouped and un-grouped data approach. Data analysis showed that design parameters had a significant effect on the drop performance and played a vital role in influencing the package reliability.

A New Approach to Calibration of Printed Circuit Board Coordinates: 2D-Depth Sensor Applied to Robotic Screwdrivers Assembly Systems

2014 ◽  
Vol 939 ◽  
pp. 445-450
Author(s):  
Shu Ping Dong ◽  
Hau Wei Wang ◽  
Tung Ying Wu ◽  
Ching Ming Yeh
Keyword(s):  
Tilt Angle ◽  
Printed Circuit Board ◽  
Angle Measurement ◽  
Consumer Electronics ◽  
Circuit Board ◽  
Depth Information ◽  
Depth Sensor ◽  
Printed Circuit Board Assembly ◽  
Printed Circuit ◽  
Vision Inspection

We consider the parts screwing problems, which of automatic assembly robotic screwdrivers system required precisely depth and tilt-angle at each insertion point. However, commonly computer vision inspection tools which obtain tilt-angle on clamping printed circuit board is a challenging problem. Further, even if given a depth senor, that still to consider inspection target size. Thus, we present an approach for screwing angle measurement of printed circuit board assembly in Consumer electronics production lines. The methods involved using 2D-Depth sensor to identify screwing angle, and measuring depth information near the hole of printed circuit board. Our method successfully conform to screwdrivers system requirement, tilt angle under three degree and sampling small area target under 10mm^2,which obtains measurement results will be applied to refer on robotic positioning and assembling.

Damage and Failures of CGA/BGA Assemblies Under Thermal Cycling and Dynamic Loadings

2013 ◽  
Author(s):  
Reza Ghaffarian
Keyword(s):  
Thermal Cycling ◽  
Mechanical Loading ◽  
Test Data ◽  
Printed Circuit Board ◽  
High Reliability ◽  
Circuit Board ◽  
Design Parameters ◽  
Mechanical Shock ◽  
Space Applications ◽  
High Processing

Commercial-off-the-shelf column/ball grid array packaging (COTS CGA/BGA) technologies in high-reliability versions are now being considered for use in high-reliability electronic systems. For space applications, these packages are prone to early failure due to the severe thermal cycling in ground testing and during flight, mechanical shock and vibration of launch, as well as other less severe conditions, such as mechanical loading during descent, rough terrain mobility, handling, and ground tests. As the density of these packages increases and the size of solder interconnections decreases, susceptibility to thermal, mechanical loading and cycling fatigue grows even more. This paper reviews technology as well as thermo-mechanical reliability of field programmable gate array (FPGA) IC packaging developed to meet demands of high processing powers. The FPGAs that generally come in CGA/PBGA packages now have more than thousands of solder balls/columns under the package area. These packages need not only to be correctly joined onto printed circuit board (PCB) for interfacing; they also should show adequate system reliability for meeting thermo-mechanical requirements of the electronics hardware application. Such reliability test data are rare or none for harsher environmental applications, especially for CGAs having more than a thousand of columns. The paper also presents significant test data gathered under thermal cycling and drop testing for high I/O PBGA/CGA packages assembled onto PCBs. Damage and failures of these assemblies after environmental exposures are presented in detail. Understanding the key design parameters and failure mechanisms under thermal and mechanical conditions is critical to developing an approach that will minimize future failures and will enable low-risk insertion of these advanced electronic packages with high processing power and in-field re-programming capability.

Failure Analysis Techniques for Lead-Free Solder Joints

2005 ◽  
Author(s):  
Todd Castello ◽  
Dan Rooney ◽  
Dongkai Shangguan
Keyword(s):  
Failure Analysis ◽  
Printed Circuit Board ◽  
Failure Modes ◽  
Circuit Board ◽  
Lead Free ◽  
Lead Free Solder ◽  
Printed Circuit Board Assembly ◽  
Analysis Techniques ◽  
Solder Interconnects ◽  
Free Solder

Abstract Printed circuit board assembly with lead free solder is now a reality for most global electronics manufacturers. Extensive research and development has been conducted to bring lead free assembly processes to a demonstrated proficiency. Failure analysis has been an integral part of this effort and will continue to be needed to solve problems in volume production. Many failure analysis techniques can be directly applied to study lead free solder interconnects, while others may require some modification in order to provide adequate analysis results. In this paper, several of the most commonly applied techniques for solder joint failure analysis will be reviewed, including visual inspection, x-ray radiography, mechanical strength testing, dye & pry, metallography, and microscopy/photomicrography, comparing their application to lead bearing and lead free solder interconnects. Common failure modes and mechanisms will be described with examples specific to lead free solders, following PCB assembly as well as after accelerated reliability tests.

High Reliability Pb-Free Printed Circuit Board Assembly

2010 ◽  
Vol 450 ◽  
pp. 9-12
Author(s):  
S.D.T. Weller ◽  
I.P. Jones ◽  
Ian M. Fox ◽  
Terry Hirst
Keyword(s):  
Process Parameters ◽  
Printed Circuit Board ◽  
High Reliability ◽  
Electroless Nickel ◽  
Cycling Performance ◽  
Circuit Board ◽  
Optimum Process ◽  
Printed Circuit Board Assembly ◽  
Circuit Board Assembly ◽  
Lead Free Solders

The solderability and reliability of SnAgCu and SnAgCuSbBiNi lead-free solders were assessed against SnPbAg solder on a range of PCB finishes. A novel solderability test has been developed to assess the solder system’s ability to realign when a deliberately inaccurate solder stencil printing process was applied. This has shown to be an excellent way to compare PCB finishes and solders, as well as define process parameters. Electroless Nickel Immersion Gold (ENIG) finish proved to give the best solderability and the optimum process parameters were also found. SnPbAg solder has shown superior thermal cycling performance compared to SnAgCu.

scholarly journals The relevance of operational skills towards business sustainability: A focus on SMME manufacturers in the Vaal triangle region

2010 ◽  
Vol 10 (1) ◽  
Author(s):  
R. Naidoo ◽  
B. Urban
Keyword(s):  
Factor Analysis ◽  
Service Providers ◽  
Manufacturing Sector ◽  
High Reliability ◽  
Theory Development ◽  
Reliability And Validity ◽  
Cross Sectional ◽  
Business Sustainability ◽  
Relational Analysis ◽  
Vaal Triangle

Purpose: Activities in the manufacturing sector are often considered the bedrock of an economy and a key driver of growth and development. Within the South African manufacturing sector, operations skills are reported to be deficient and are often cited as a main cause of failure in small, medium and micro enterprises (SMMEs). This study explores and tests this fragile relationship between operations skills and SMME sustainability. Empirical investigations are conducted in a high-density SMME manufacturing environment - the Vaal Triangle Region. Design/Methodology/Approach: Building on previously established literature on SMME sustainability and operations skills, various measures are developed and tested for reliability and validity. Factor analysis is used to identify relevant factors in terms of operations skills. Co-relational analysis is then employed to test the hypothesised relationship. The study is cross-sectional in design and relies on trained fieldworkers administering surveys for data collection. Findings: Five clear factors for operations skills are identified through factor analysis with an overall high reliability value. Based on descriptive and co-relational analysis results reveal that operations skills are positively associated with sustainability. Implications: SMME owners, educators and service providers may benefit from the study's findings in terms of the nature and associations that operational skills have on developing sustainable SMME's. Originality/Value: The study focused on a neglected area of SMMEs - the importance of operations towards business sustainability, and made an important contribution towards theory development through empirical explorations. In South Africa, this is the first time an instrument measuring operations skills has been validated and associated with SMMEs in a manufacturing context.

KEMET SMD Film Capacitors for High Temperature Applications

2013 ◽  
Vol 2013 (HITEN) ◽  
pp. 000013-000024 ◽  
Author(s):  
Luca Caliari ◽  
Paola Bettacchi ◽  
Evangelista Boni ◽  
Davide Montanari ◽  
Arrigo Gamberini ◽  
...  
Keyword(s):  
High Temperature ◽  
High Reliability ◽  
Ac Loss ◽  
Shock Acceleration ◽  
Hole Drilling ◽  
Harsh Environment ◽  
Mechanical Shock ◽  
Component Level ◽  
Film Capacitor ◽  
Low Leakage

Trends of several applications like down-hole drilling, commercial aviation (e.g. jet engines), heavy industrial and automotive are challenging the capabilities of capacitors and other electronic components. The growing harsh-environment conditions for these applications are: high temperature, high voltage and high current. At the capacitor component level, required features are: very high reliability under mechanical shock, rapid changes in temperature, low leakage current (high insulation resistance), small dimensions, good stability with time and humidity, and high peak withstanding voltage. Capacitors for power-conversion circuitry must maintain a low AC loss and DC leakage at high temperatures. KEMET has recently designed film capacitor series using PEN to address the needs of the above mentioned circuits, in particular regarding the working temperature, voltage and current. This paper will cover technological advances in film capacitor technology to address harsh environment conditions needs, providing test results on temperature, voltage and thermal shock acceleration factor.

scholarly journals Assessment of Factors Affecting Attendance of Antenatal Care in Kagote Health Center III, Kabarole District, Uganda

2021 ◽  
Author(s):  
◽  
MARGARET APISO
Keyword(s):  
Antenatal Care ◽  
Health Facility ◽  
Sampling Method ◽  
Service Providers ◽  
Health Workers ◽  
Reproductive Age ◽  
Evaluation Methodology ◽  
Long Distance ◽  
Cross Sectional ◽  
Factors Affecting

Background: Antenatal care is generally thought to be an effective method of improving outcomes in pregnant women and their babies, although many specific Antenatal Care practices have not been subject to rigorous evaluation Methodology: A descriptive cross-sectional study was carried out in Kagote HCIII aimed at assessing the factors affecting ANC attendance in the Kabarole district. Using a convenience sampling method, Kagote HCIII was chosen by the random sampling method. A sample of 100 respondents was interviewed. Questionnaires were used to obtain data from the individuals and these were in form of closed and open-ended questions. Results: The majority of the respondents 92(92%) used ANC information in subsequent pregnancies. 48(48%) said that multiparous women did not need to attend ANC if they were healthy while 12% were not sure. Challenges include long distance from the ANC clinic 32(13%), harsh health service providers 8(3%), lack enough support from husbands 22(9%), segregation and discrimination 12(5%), negative attitude towards ANC 16(7%), high transport costs 37(15.4%), lack of enough money 43(18%), lack of enough time 10(4%), too much workload at home 16(7%), long waiting time 20(8.3%), unavailability of some drugs at times 24(10%). Conclusion and recommendation: The factors affecting ANC attendance in Kagote HCIII are; age, occupation, education level, marital status, address, the number of health workers, their cadre, skill, authority, knowledge, nature, the services they and how they offer them, availability of incentives like drugs, multiparity, the order of pregnancy and the challenges mentioned above.  There is a need for the MOH to continue sensitizing people about the importance of ANC attendance, outreaches by the health facility to the community to offer the service and encourage attendance, a collaboration between the health facility and the village health team continued health education of women of reproductive age about ANC and its attendance. 

scholarly journals Health Status and Quality of Health Care Services of Congolese Refugees in Nakivale, Uganda

2016 ◽  
Vol 5 (3) ◽  
pp. 39
Author(s):  
Amegovu K. Andrew
Keyword(s):  
Health Status ◽  
Health Services ◽  
Resource Constraints ◽  
Service Providers ◽  
Geographic Origin ◽  
Health Service Delivery ◽  
Health Facilities ◽  
Cross Sectional ◽  
Adequate Food

Physical and emotional wellness, as well as access to healthcare, are foundations for successful resettlement. Without feeling healthy, it is difficult to work, to go school, or take care of a family. Many factors can affect refugee health, including geographic origin and refugee camp conditions. Refugees may face a wide variety of acute or chronic health issues (Office of Refugee Resettlement, ORR Annual Report to Congress 2014; http://www.acf.hhs.gov). Resettlement of refugees in Uganda is usually supported by concerted efforts of UNHCR, Governments through the Office of the Prime Minister, OPM with support from host communities, local and international Non-Governmental Organizations. Due to resource constraints and local factors, immigrants are often subjected to poor living conditions which coupled with inadequacy inessential medical supplies might significantly affects quality of care and health service delivery and hence, rendering refugees to poor health status. This study was conducted from 2013-2014 to assess the determinants of health status of Congolese refugees living in Nakivale refugee settlement, in Isingiro district- South Western Uganda. A cross-sectional study design was used involving mixed techniques of both qualitative and quantitative KAP survey. The study focussed on Congolese refugee population in Nakivale Refugee settlement. 2401 key informants’ interviews and 8 focus group discussions respectively were conducted targeting service providers and beneficiaries/Congolese refugees in this case. The data was analysed using SPSS ver.20, 2011. Although majority (97%) of respondents sought medical services from established health facilities, findings confirm a high level of ill health prevalence among Congolese refugees in Nakivale camp, however, the difference in health services and perceived health status in camp versus the one in DRcongo is insignificant ( p=0.000) with respondents perceiving their health status as worse than when they were their own Country before the resettlement. Identified key challenges affecting access & uptake of available health services includes: language barrier; inadequate drugs; and the long distances to access health facilities. The health status of refugees could be improved by addressing the challenges related to language, drug supplies in addition to humanising conditions of shelter, providing appropriate waste disposal facilities while proving adequate food rations and clean & safe drinking water.

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