Dr. Rajeshuni Ramesham Profile

Dr. Rajeshuni Ramesham

at Jet Propulsion Lab

SPIE Involvement:

Editor | Author

Proceedings Article | 7 March 2014 Paper

HALT to qualify electronic packages: a proof of concept

Rajeshuni Ramesham

Proceedings Volume 8975, 89750J (2014) https://doi.org/10.1117/12.2038319

KEYWORDS: Resistance, Reliability, Packaging, Accelerated life testing, Cerium, Electronic components, Niobium, Space operations, Temperature metrology, Capacitors

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A proof of concept of the Highly Accelerated Life Testing (HALT) technique was explored to assess and optimize electronic packaging designs for long duration deep space missions in a wide temperature range (–150°C to +125°C). HALT is a custom hybrid package suite of testing techniques using environments such as extreme temperatures and dynamic shock step processing from 0g up to 50g of acceleration. HALT testing used in this study implemented repetitive shock on the test vehicle components at various temperatures to precipitate workmanship and/or manufacturing defects to show the weak links of the designs. The purpose is to reduce the product development cycle time for improvements to the packaging design qualification. A test article was built using advanced electronic package designs and surface mount technology processes, which are considered useful for a variety of JPL and NASA projects, i.e. (surface mount packages such as ball grid arrays (BGA), plastic ball grid arrays (PBGA), very thin chip array ball grid array (CVBGA), quad flat-pack (QFP), micro-lead-frame (MLF) packages, several passive components, etc.). These packages were daisy-chained and independently monitored during the HALT test. The HALT technique was then implemented to predict reliability and assess survivability of these advanced packaging techniques for long duration deep space missions in much shorter test durations. Test articles were built using advanced electronic package designs that are considered useful in various NASA projects. All the advanced electronic packages were daisychained independently to monitor the continuity of the individual electronic packages. Continuity of the daisy chain packages was monitored during the HALT testing using a data logging system. We were able to test the boards up to 40g to 50g shock levels at temperatures ranging from +125°C to -150°C. The HALT system can deliver 50g shock levels at room temperature. Several tests were performed by subjecting the test boards to various g levels ranging from 5g to 50g, test durations of 10 minutes to 60 minutes, hot temperatures of up to +125°C and cold temperatures down to -150°C. During the HALT test, electrical continuity measurements of the PBGA package showed an open-circuit, whereas the BGA, MLF, and QFPs showed signs of small variations of electrical continuity measurements. The electrical continuity anomaly of the PBGA occurred in the test board within 12 hours of commencing the accelerated test. Similar test boards were assembled, thermal cycled independently from -150°C to +125°C and monitored for electrical continuity through each package design. The PBGA package on the test board showed an anomalous electrical continuity behavior after 959 thermal cycles. Each thermal cycle took around 2.33 hours, so that a total test time to failure of the PBGA was 2,237 hours (or ~3.1 months) due to thermal cycling alone. The accelerated technique (thermal cycling + shock) required only 12 hours to cause a failure in the PBGA electronic package. Compared to the thermal cycle only test, this was an acceleration of ~186 times (more than 2 orders of magnitude). This acceleration process can save significant time and resources for predicting the life of a package component in a given environment, assuming the failure mechanisms are similar in both the tests. Further studies are in progress to make systematic evaluations of the HALT technique on various other advanced electronic packaging components on the test board. With this information one will be able to estimate the number of mission thermal cycles to failure with a much shorter test program. Further studies are in progress to make systematic study of various components, constant temperature range for both the tests. Therefore, one can estimate the number of hours to fail in a given thermal and shock levels for a given test board physical properties.

Proceedings Article | 9 March 2013 Paper

Life testing of reflowed and reworked advanced CCGA surface mount packages in harsh thermal environments

Rajeshuni Ramesham

Proceedings Volume 8614, 86140L (2013) https://doi.org/10.1117/12.2001410

KEYWORDS: Resistance, Reliability, Temperature metrology, Manufacturing, Packaging, X-ray imaging, Electrical breakdown, Copper, Photography, Interfaces

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Life testing/qualification of reflowed (1^st reflow) and reworked (1^st reflow, 1^st removal, and then 1^st rework) advanced ceramic column grid array (CCGA) surface mount interconnect electronic packaging technologies for future flight projects has been studied to enhance the mission assurance of JPL-NASA projects. The reliability of reworked/reflowed surface mount technology (SMT) packages is very important for short-duration and long-duration deep space harsh extreme thermal environmental missions. The life testing of CCGA electronic packages under extreme thermal environments (for example: -185°C to +125°C) has been performed with reference to various JPL/NASA project requirements which encompass the temperature range studied. The test boards of reflowed and reworked CCGA packages (717 Xilinx package, 624, 1152, and 1272 column Actel Packages) were selected for the study to survive three times the total number of expected temperature cycles resulting from all environmental and operational exposures occurring over the life of the flight hardware including all relevant manufacturing, ground operations, and mission phases or cycles to failure to assess the life of the hardware. Qualification/life testing was performed by subjecting test boards to the environmental harsh temperature extremes and assessing any structural failures, mechanical failures or degradation in electrical performance solder-joint failures due to either overstress or thermal cycle fatigue. The large, high density, high input/output (I/O) electronic interconnect SMT packages such as CCGA have increased usage in avionics hardware of NASA projects during the last two decades. The test boards built with CCGA packages are expensive and often require a rework to replace a reflowed, reprogrammed, failed, redesigned, etc., CCGA packages. Theoretically speaking, a good rework process should have similar temperature-time profile as that used for the original manufacturing process of solder reflow. A multiple rework processes may be implemented with CCGA packaging technology to understand the effect of number of reworks on the reliability of this technology for harsh thermal environments. In general, reliability of the assembled electronic packages reduces as a function of number of reworks and the extent is not known yet. A CCGA rework process has been tried and implemented to design a daisy-chain test board consists of 624 and 717 packages. Reworked CCGA interconnect electronic packages of printed wiring polyimide boards have been assembled and inspected using non-destructive x-ray imaging and optical microscope techniques. The assembled boards after 1^st rework and 1^st reflow were subjected to extreme temperature thermal atmospheric cycling to assess their reliability for future deep space JPL/NASA for moderate to harsh thermal mission environments. The resistance of daisy-chained interconnect sections were monitored continuously during thermal cycling to determine intermittent failures. This paper provides the experimental reliability test results to failure of assemblies for the first time of reflowed and reworked CCGA packages under extreme harsh thermal environments.

SPIE Journal Paper | 29 June 2012 Open Access

Special Section Guest Editorial: Reliability, Packaging, Testing, and Characterization of MOEMS and MEMS III

Sonia García-Blanco, Rajeshuni Ramesham

JM3, Vol. 11, Issue 02, 021201, (June 2012) https://doi.org/10.1117/12.10.1117/1.JMM.11.2.021201

KEYWORDS: Reliability, Packaging, Microopto electromechanical systems, Microelectromechanical systems, Nanostructures, Nanofabrication

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Proceedings Article | 15 February 2012 Paper

Reliability of high I/O high density CCGA interconnect electronic packages under extreme thermal environments

Rajeshuni Ramesham

Proceedings Volume 8250, 82500A (2012) https://doi.org/10.1117/12.913558

KEYWORDS: Reliability, Temperature metrology, Inspection, Resistance, Ceramics, Packaging, X-rays, Interfaces, Space operations, Nondestructive evaluation

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Proceedings Article | 18 February 2011 Paper

Reliability of Sn/Pb and lead-free (SnAgCu) solders of surface mounted miniaturized passive components for extreme temperature (-185 degrees C to +125 degrees C) space missions

Rajeshuni Ramesham

Proceedings Volume 7928, 79280F (2011) https://doi.org/10.1117/12.873466

KEYWORDS: Reliability, Resistance, Temperature metrology, Lead, Nickel, Resistors, Space operations, Optical fabrication, Inspection, Packaging

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SPIE Journal Paper | 1 October 2010 Open Access

Special Section Guest Editorial: Reliability, Packaging, Testing, and Characterization of MEMS and MOEMS II

Rajeshuni Ramesham

JM3, Vol. 9, Issue 04, 041101, (October 2010) https://doi.org/10.1117/12.10.1117/1.3533418

KEYWORDS: Packaging, Reliability, Microelectromechanical systems, Microopto electromechanical systems, Switches, Nanomaterials, Sensors, Dielectric breakdown, Deformable mirrors

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Proceedings Article | 5 February 2010 Paper

Reliability assessment of ceramic column grid array (CCGA717) interconnect packages under extreme temperatures for space applications (-185°C to +125°C)

Rajeshuni Ramesham

Proceedings Volume 7592, 75920F (2010) https://doi.org/10.1117/12.844998

KEYWORDS: Reliability, Resistance, Temperature metrology, Ceramics, Packaging, Inspection, Interfaces, Copper, X-rays, Electronics

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Ceramic Column Grid Array packages have been increasing in use based on their advantages such as high interconnect density, very good thermal and electrical performance, compatibility with standard surface-mount packaging assembly processes, etc. CCGA packages are used in space applications such as in logics and microprocessor functions, telecommunications, flight avionics, payload electronics, etc. As these packages tend to have less solder joint strain relief than leaded packages, the reliability of CCGA packages is very important for short and long-term space missions. CCGA interconnect electronic package printed wiring boards (PWBs) of polyimide have been assembled, inspected non-destructively and subsequently subjected to extreme temperature thermal cycling to assess the reliability for future deep space, short and long-term, extreme temperature missions. In this investigation, the employed temperature range covers from -185°C to +125°C extreme thermal environments. The test hardware consists of two CCGA717 packages with each package divided into four daisy-chained sections, for a total of eight daisy chains to be monitored. The CCGA717 package is 33 mm × 33 mm with a 27×27 array of 80%/20% Pb/Sn columns on a 1.27 mm pitch. The resistance of daisy-chained, CCGA interconnects were continuously monitored as a function of thermal cycling. Electrical resistance measurements as a function of thermal cycling are reported and the tests to date have shown significant change in daisy chain resistance as a function of thermal cycling. The change in interconnect resistance becomes more noticeable with increasing number of thermal cycles. This paper will describe the experimental test results of CCGA testing under wide extreme temperatures. Standard Weibull analysis tools were used to extract the Weibull parameters to understand the CCGA failures. Optical inspection results clearly indicate that the solder joints of columns with the board and the ceramic package have failed as a function of thermal cycling. The first failure was observed at 137th thermal cycle and 63.2% failures of daisy chains have occurred at about 664 thermal cycles. The shape parameter extracted from Weibull plot was about 1.47 which indicates the failures were related to failures occurred during the flat region or useful life region of standard bath tub curve. Based on this experimental test data one can use the CCGAs for the temperature range studied for ~100 thermal cycles (ΔT = 310°C, 5oC/minute, and 15 minutes dwell) with high degree of confidence for high reliability space and other applications.

SPIE Journal Paper | 1 July 2009 Open Access

Guest Editorial: Reliability, Packaging, Testing, and Characterization of MEMS and MOEMS

Rajeshuni Ramesham, Allyson Hartzell

JM3, Vol. 8, Issue 03, 031301, (July 2009) https://doi.org/10.1117/12.10.1117/1.3236753

KEYWORDS: Reliability, Packaging, Microelectromechanical systems, Microopto electromechanical systems, Nanofabrication

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SPIE Journal Paper | 1 July 2009

Review of vacuum packaging and maintenance of MEMS and the use of getters therein

Rajeshuni Ramesham, Richard Kullberg

JM3, Vol. 8, Issue 03, 031307, (July 2009) https://doi.org/10.1117/12.10.1117/1.3158064

KEYWORDS: Microelectromechanical systems, Hydrogen, Packaging, Gases, Carbon monoxide, Infrared sensors, Manufacturing, Zirconium, Sensors, Gyroscopes

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Proceedings Article | 9 February 2009 Paper

Environmental testing of COTS components for space applications

Rajeshuni Ramesham

Proceedings Volume 7206, 72060H (2009) https://doi.org/10.1117/12.813408

KEYWORDS: Microelectromechanical systems, Commercial off the shelf technology, Sensors, Reliability, Packaging, Aerospace engineering, Environmental sensing, Gyroscopes, Electronics, Microsystems

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Proceedings Article | 18 February 2008 Paper

Qualification testing of engineering camera and platinum resistance thermometer (PRT) sensors for Mars Science Laboratory (MSL) project under extreme temperatures to assess reliability and to enhance mission assurance

Rajeshuni Ramesham, Justin Maki, Gordon Cucullu

Proceedings Volume 6884, 68840E (2008) https://doi.org/10.1117/12.765274

KEYWORDS: Mars, Cameras, Reliability, Sensors, Platinum, Resistance, Packaging, Temperature metrology, Atmospheric modeling, Environmental sensing

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Proceedings Article | 18 August 1999 Paper

Reliability issues of COTS MEMS for aerospace applications

Rajeshuni Ramesham, Reza Ghaffarian, Namsoo Kim

Proceedings Volume 3880, (1999) https://doi.org/10.1117/12.359357

KEYWORDS: Microelectromechanical systems, Reliability, Packaging, Sensors, Commercial off the shelf technology, Silicon, Aerospace engineering, Humidity, Environmental sensing, Standards development

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Proceedings Article | 20 November 1992 Paper

Selective diamond seed deposition using electroplated copper

Rajeshuni Ramesham

Proceedings Volume 1759, (1992) https://doi.org/10.1117/12.130756

KEYWORDS: Diamond, Copper, Particles, Chemical vapor deposition, Plating, Molybdenum, Thin films, Photomicroscopy, Photoresist materials, Electroplating

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Showing 5 of 13 publications

SPIE Conference Volume | 19 March 2014

Reliability, Packaging, Testing, and Characterization of MOEMS/MEMS, Nanodevices, and Nanomaterials XIII

SPIE Conference Volume | 26 March 2013

Reliability, Packaging, Testing, and Characterization of MOEMS/MEMS and Nanodevices XII

SPIE Conference Volume | 16 March 2012

Reliability, Packaging, Testing, and Characterization of MEMS/MOEMS and Nanodevices XI

SPIE Conference Volume | 11 February 2011

Reliability, Packaging, Testing, and Characterization of MEMS/MOEMS and Nanodevices X

SPIE Conference Volume | 4 February 2010

Reliability, Packaging, Testing, and Characterization of MEMS/MOEMS and Nanodevices IX

Showing 5 of 14 publications

Conference Committee Involvement (22)

Reliability, Packaging, Testing, and Characterization of MOEMS/MEMS, Nanodevices, and Nanomaterials XIII

3 February 2014 | San Francisco, California, United States

SPIE MOEMS-MEMS

1 February 2014 | San Francisco, United States

Reliability, Packaging, Testing, and Characterization of MOEMS/MEMS and Nanodevices XII

4 February 2013 | San Francisco, California, United States

SPIE MOEMS-MEMS

2 February 2013 | San Francisco, United States

Reliability, Packaging, Testing, and Characterization of MEMS/MOEMS and Nanodevices XI

23 January 2012 | San Francisco, California, United States

Reliability, Packaging, Testing, and Characterization of MEMS/MOEMS and Nanodevices X

24 January 2011 | San Francisco, California, United States

SPIE MOEMS-MEMS

22 January 2011 | San Francisco, United States

Reliability, Packaging, Testing, and Characterization of MEMS/MOEMS and Nanodevices IX

25 January 2010 | San Francisco, California, United States

Reliability, Packaging, Testing, and Characterization of MEMS/MOEMS and Nanodevices VIII

28 January 2009 | San Jose, California, United States

Reliability, Packaging, Testing, and Characterization of MEMS/MOEMS VII

21 January 2008 | San Jose, California, United States

MOEMS-MEMS 2008 Micro and Nanofabrication

19 January 2008 | San Jose, United States

Reliability, Packaging, Testing, and Characterization of MEMS/MOEMS VI

23 January 2007 | San Jose, California, United States

MOEMS-MEMS 2007 Micro and Nanofabrication

20 January 2007 | San Jose, United States

Reliability, Packaging, Testing, and Characterization of MEMS/MOEMS V

25 January 2006 | San Jose, California, United States

MOEMS-MEMS 2006 Micro and Nanofabrication

21 January 2006 | San Jose, United States

Reliability, Packaging, Testing, and Characterization of MEMS/MOEMS IV

25 January 2005 | San Jose, California, United States

MOEMS-MEMS Micro and Nanofabrication

22 January 2005 | San Jose, United States

Reliability, Testing, and Characterization of MEMS/MOEMS III

26 January 2004 | San Jose, California, United States

Micromachining and Microfabrication

24 January 2004 | San Jose, United States

Reliability, Testing, and Characterization of MEMS/MOEMS II

27 January 2003 | San Jose, CA, United States

Reliability, Testing, and Characterization of MEMS/MOEMS

22 October 2001 | San Francisco, CA, United States

MEMS Reliability for Critical and Space Applications

21 September 1999 | Santa Clara, CA, United States

Showing 5 of 22 Conference Committees

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