Digitally Printed Battery: Transitioning from a Traditional Coated Battery Design to a Digitally Printed Battery; Advantages,Challenges and Successes

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The company is a producer of thin film batteries of less than 0.45mm in thickness. Battery operated devices have grown
smaller and smaller while energy demands have increased as the need for increased functionality has grown. This need has
led designers,which would normally use conventionally sized batteries,to consider other types and form factors. Products
such as powered display transaction cards,RFID/sensor tags,and medical device patches have created a market for thin film
batteries.
The following provides a brief review of battery construction. All batteries are basically made up of an anode (lithium in this
case) and a cathode (MnO2 in this case),separated by a mechanical barrier (separator layer) designed to prevent internal
electrical connectivity. The trick with the separator layer is to minimize resistance within the battery by being thin while not
too thin as to promote soft shorts,limiting the life of the battery.

Author(s)
Dan Tillwick
Resource Type
Technical Paper
Event
IPC APEX EXPO 2014

Substrates: Polyester Film for the Flexible Electronics Industry

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Polyester film substrates have been widely used in making flexible / printed electronic devices for over 30 years. However the early 2000’s brought about an explosion of interest in “additive” printed electronics in terms of developing materials and device technology while exploring new business opportunities. This next generation of Flexible Electronics technologies has required materials suppliers to deliver improved functionalities to the device developers in fields as wide as electrophoretic displays,backplanes,barrier films,sensors etc... Over this period,substrate suppliers have worked closely with the flexible electronics community to understand and define the evolving film requirements of this embryonic industry. This presentation will initially give an overview of substrate evolution for flexible electronics,exploring the typical issues associated with substrate development and selection. The talk will then lead on to discuss the latest film developments in support of the flexible electronics industry,including dimensional stability,environmental protection,surface quality,refractive index matching,and optical clarity.

Author(s)
Scott Gordon
Resource Type
Slide Show
Event
IPC APEX EXPO 2014

Advanced Printing for Microelectronic Packaging

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Using micro-dispensing with exceptional volume control it is possible to print in 3D space a wide variety of materials and including solders,epoxies,conductive adhesives and ceramic filled polymers. These can be used to build 3D structures and utilizing a 3D Printing approach which is also known as Computer Aided Design and Computer Aided Manufacturing (CAD/CAM). The advanced technology enables 3D printing of electronics but it also enables smaller solder and adhesive dots; 75 microns and less. It is possible to place these on any package in 3D space. Demonstrations for this technology have shown that it is possible to print less than 50 micron wide lines and dots. Additionally a wide range of materials that will be required in future packaging can be dispensed. These smaller features provide sub nanoliter volume. This is possible given the less than 100 picoliter volume control during dispensing and including highly viscous materials. Demonstrations of smaller printed dots and lines for electronic circuits and packaging will be shown. In addition,3D circuitry that is 3D printed and contains no solder will also be shown,demonstrating the future of printed circuits.

Author(s)
Kenneth H. Church,Xudong Chen,Joshua M. Goldfarb,Casey W. Perkowski,Samuel LeBlanc
Resource Type
Technical Paper
Event
IPC APEX EXPO 2014

Good Product Quality Comes From Good Design for Test Strategies

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Product quality can be improved through proper application of design for test (DFT) strategies. With today’s shrinking product sizes and increasing functionality,it is difficult to get good test coverage of loaded printed circuit boards due to the loss of test access. Advances in test techniques,such as boundary scan,help to recover this loss of test coverage. However,many of these test techniques need to be designed into the product to be effective. This paper will discuss how to maximize the benefits of boundary scan test,including specific examples of how designers should select the right component,connect multiple boundary scan components in chains,add test access to the boundary scan TAP ports,etc. A discussion of DFT guidelines for PCB layout designers is also included. Finally,this paper will include a description of some advanced test methods used in in-circuit tests,such as vectorless test and special probing methods,which are implemented to improve test coverage on printed circuit boards with limited test access.

Author(s)
Adrian Cheong
Resource Type
Technical Paper
Event
IPC APEX EXPO 2014

Board-Assist Built-In Self-Test (BA-BIST),Short-Term and Long-Term Strategies for Use Case Standardization

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This iNEMI program's focus is on a “Chip” Built-in Self-Test (BIST) study and its promotion for board and system-level applications. In this case,This study has 2 strategic focus areas – short term that involves “what chips already have”; and long term that involves “defining specific chip content to meet board test goals.” Presently,there are there are too many algorithms and too many interfaces – some standard and some custom – there is no agreement across the industry as to a “single” standard. In addition,the algorithms are usually standard and are for IC Test which are overkill for board test. In fact,the term BIST is overloaded in that it can be used by IC providers in association with Logic,Memory,SerDes,PLL’s and other functions. Most “chip” level BISTs are designed to aid IC manufacturing; these tests and algorithms are often not suitable or available to run at the board level – but if thay can be operated by board test,they can usually be used to meet some board test needs. The goal of this iNEMI program is to:
• Develop and promote the adoption of IC BIST to meet test and debug needs at the board/system level,
• Encourage IC vendors to provide standard chip BIST access interfaces and algorithms for board test and debug
• Encourage ATE/Instrument providers to develop products based on existing related standards for BIST design.

For example,an IEEE 1500/P1687 globalized Test Cost Model useful throughout the industry. The iNEMI BIST Program consists of four phases: 1. Survey on BIST availability,usage,access at board level test (Phase 1 - complete). 2. Component BIST Use Case Investigation Project (Phase 2 - complete). 3. Component BIST Short-Term and Long-Term Strategies for Use Case Classification Project (Phase 3 – in progress). 4. Board Level Test Recommendations for Standardization of Component BIST (Phase 4). The work presented here by the iNEMI Built-In Self-Test (BIST) Project,Phase 3 Short-Term and Long-Term Strategies for Use Case Standardization,takes a more comprehensive view of the problem. The thrust of the work investigates and identifies a function classification of the “Use Case” as defined in the BIST “Use Case” Investigation Project (Phase 2 – “What are my board Test Problems that a BIST could Assist”),where the proposed Use Case incorporates an ASIC/CPU/FPGA to memory interface. The classification includes the following tasks: Listing of tests and tasks performed; logic/features involved in the tasks and tests; access,control,and configuration requirements; test,function,and feature access to set up and run tests.

Author(s)
Zoë Conroy,Al Crouch
Resource Type
Slide Show
Event
IPC APEX EXPO 2014

Boundary-Scan Project Phase 3: Investigation into Challenges of using .BSDL Files

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The number one issue identified by the 2009 iNEMI Boundary-Scan survey was problems with obtaining correct and compliant boundary-scan description language (.bsdl) files from the semiconductor industry for use in boundary-scan printed circuit board assembly (PCBA) test generation. The major conclusions from the survey were:
• The semiconductor industry needs to make a greater effort to produce correct and compliant BSDLs.
• A better job needs to be done verifying JTAG hardware compliance to .bsdl files.

Non-compliance is typically found when a test is generated and it doesn’t work! The consequences of not having correct and compliant .bsdl file to generate boundary-scan tests is the inability to generate boundary-scan and if tests cannot be generated,the result is lower overall test coverage for PCBAs,resulting in higher manufacturing costs and lower overall product quality. The work presented here by the iNEMI Boundary Scan Phase 3: Investigation into Challenges of Using .BSDL Files Project group takes a more comprehensive view of the problem by surveying the industry to determine if issues associated with IEEE 1149.1 .bsdl files identified in the 2009 iNEMI Boundary-Scan survey still exist,and if so to what extent,and identify any new issues. Based on the data obtained,the results will be used to raise industry awareness of the issues and potential solutions. Current and best practices for .bsdl file creation and validation will be identified and documented.

Author(s)
Philip B. Geiger
Resource Type
Slide Show
Event
IPC APEX EXPO 2014

Boundary-Scan Project Phase 3:Investigation into Challenges of using .BSDL Files

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The number one issue identified by the 2009 iNEMI Boundary-Scan survey was problems with obtaining correct and compliant boundary-scan description language (.bsdl) files from the semiconductor industry for use in boundary-scan printed circuit board assembly (PCBA) test generation. The major conclusions from the survey were:
• The semiconductor industry needs to make a greater effort to produce correct and compliant BSDLs.
• A better job needs to be done verifying JTAG hardware compliance to .bsdl files.

Non-compliance is typically found when a test is generated and it doesn’t work! The consequences of not having correct and compliant .bsdl file to generate boundary-scan tests is the inability to generate boundary-scan and if tests cannot be generated,the result is lower overall test coverage for PCBAs,resulting in higher manufacturing costs and lower overall product quality. The work presented here by the iNEMI Boundary Scan Phase 3: Investigation into Challenges of Using .BSDL Files Project group takes a more comprehensive view of the problem by surveying the industry to determine if issues associated with IEEE 1149.1 .bsdl files identified in the 2009 iNEMI Boundary-Scan survey still exist,and if so to what extent,and identify any new issues. Based on the data obtained,the results will be used to raise industry awareness of the issues and potential solutions. Current and best practices for .bsdl file creation and validation will be identified and documented.

Author(s)
Philip B. Geiger
Resource Type
Technical Paper
Event
IPC APEX EXPO 2014

Implementing Robust Bead Probe Test Processes into Standard Pb-Free Assembly

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Increasing system integration and component densities continue to significantly reduce the opportunity to access nets using standard test points. Over time the size of test points has been drastically reduced (as small as 0.5 mm in diameter) but current product design parameters have created space and access limitations that remove even the option for these test points. Many high speed signal lines have now been restricted to inner layers only. Where surface traces are still available for access,bead probe technology is an option that reduces test point space requirements as well as their effects on high speed nets and distributes mechanical loading away from BGA footprints enabling test access and reducing the risk of mechanical defects associated with the concentration of ICT spring forces under BGA devices.
Building on Celestica's previous work characterizing contact resistance associated with Pr-free compatible surface finishes and process chemistry; this paper will describe experimentation to define a robust process window for the implementation of bead probe and similar bump technology that is compatible with standard Pb-free assembly processes. Test Vehicle assembly process,test methods and "Design of Experiments" will be described. Bead Probe formation and deformation under use will also be presented along with selected results.

Author(s)
John McMahon,Tom Blaszczyk,Peter Barber
Resource Type
Technical Paper
Event
IPC APEX EXPO 2014

Stereo Vision Based Automated Solder Ball Height Detection

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Solder ball height inspection is essential to the detection of potential connectivity issues in semi-conductor units. Current ball height inspection tools such as laser profiling,fringe projection and confocal microscopy are expensive,require complicated setup and are slow,which makes them difficult to use in a real-time manufacturing setting. Therefore,a reliable,in-line ball height measurement method is needed for inspecting units undergoing assembly.
Existing stereo vision measurement techniques determine the height of objects by detecting corresponding feature points in two views of the same scene taken from different viewpoints. After detecting the matching feature points,triangulation methods are used to determine the height or depth of an object. The issue with existing techniques is that they rely on the presence of edges,corners and surface texture for the detection of feature points. Therefore,these techniques cannot be directly applied to the measurement of solder ball height due to the textureless,edgeless,smooth surfaces of solder balls.
In this paper,an automatic,stereo vision based,in-line ball height inspection method is presented. The proposed method includes an imaging setup together with a computer vision algorithm for reliable,in-line ball height measurement. The imaging set up consists of two different cameras mounted at two opposing angles with ring lighting around each camera lens which allows the capture of two images of a semi-conductor package in parallel. The lighting provides a means to generate features on the balls which are then used to determine height. Determining and grouping points with the same intensity on the ball surface allows the formation of curves,also known as iso-contours,which are then matched between the two views. Finally,an optimized triangulation is performed to determine ball height. The method has been tested on 3 products and exhibits accuracy within 4um mean squared error compared to confocal ground truth height,and the coplanarity of BGA package as derived from calculated substrate depth results.

Author(s)
Jinjin Li,Bonnie L. Bennett,Lina J. Karam,Jeff S. Pettinato
Resource Type
Technical Paper
Event
IPC APEX EXPO 2014

Study on Solder Joint Reliability of Fine Pitch CSP

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Nowadays,consumer electronic product is characterized with miniature,portable,light and high performance,especially for 3G mobile products. More and more fine pitch CSPs (0.4mm) come forth as the times require. However,there’s great challenge related to product reliability when applying Fine pitch CSP. Firstly,Fine pitch CSP has smaller solder balls,0.25mm diameter or even smaller. The small solder ball and pad size will weaken solder connection and adhesive between pad and substrate. Thus pad will peel off easily from PCB substrate. What’s more,miniature solder joint reduces the resistance against mechanical vibration,thermal shock and fatigue failure,etc. Secondly,depositing sufficient solder paste evenly on the small pad of CSP is difficult because stencil opening is only 0.25mm or less which can be solved with higher class stencil,while corresponding higher cost is needed. For this study,we focus these items: • Reliability performance of different SMD or NSMD pads; • Bigger pad size with higher adhesive strength; • Different IMCs and different results(such as Ni crack or thick IMC); • Huge improvement of underfill on CSP; • How to make a better solder paste deposition on pad rely on vacuum support; • How a reliable solder joint grow on the basis of optimized reflow profile;

Author(s)
Yong (Hill) Liang,Hank Mao,YongGang Yan,Jingdong (King) Lee
Resource Type
Technical Paper
Event
IPC APEX EXPO 2014