Knowing how package warpage changes over temperature is a critical variable in order to assemble reliable surface mount attached technology. Component and component or component and board surfaces must stay relatively flat with one another or surface mount defects,such as head-in-pillow,open joints,bridged joints,stretched joints,etc. may occur. Initial package flatness can be affected by numerous aspects of the component manufacturing and design. However,change in shape over temperature is primarily driven by CTE mismatch between the different materials in the package. Thus material CTE is a critical factor in package design. When analyzing or modeling package warpage,one may assume that the package receives heat evenly on all sides,when in production this may not be the case. Thus,in order to understand how temperature uniformity can affect the warpage of a package,a case study of package warpage versus different heating spreads is performed. Packages used in the case study have larger formfactors,so that the effect of non-uniformity can be more readily quantified within each package. Small and thin packages are less prone to issues with package temperature variation,due to the ability for the heat to conduct through the package material and make up for uneven sources of heat. Multiple packages and multiple package form factors are measured for warpage via a shadow moiré technique while being heated and cooled through reflow profiles matching real world production conditions. Heating of the package is adjusted to compare an evenly heated package to one that is heated unevenly and has poor temperature uniformity between package surfaces. The warpage is measured dynamically as the package is heated and cooled. Conclusions are drawn as to how the role of uneven temperature spread affects the package warpage.

This paper focuses on three different coating material groups which were formulated to operate under high thermal stress and are applied at printed circuit board manufacturing level. While used for principally different applications,these coatings have in common that they can be key to a successful thermal management concept especially in e-mobility and lighting applications. The coatings consist of: Specialty (green transparent) liquid photoimageable solder masks (LPiSM) compatible with long-term thermal storage/stress in excess of 150°C. Combined with the appropriate high-temperature base material,and along with a suitable copper pre-treatment,these solder resists are capable of fulfilling higher thermal demands. In this context,long-term storage tests as well as temperature cycling tests were conducted. Moreover,the effect of various Cu pre-treatment methods on the adhesion of the solder masks was examined following 150,175 and 200°C ageing processes. For this purpose,test panels were conditioned for2000 hours at the respective temperatures and were submitted to a cross-cut test every 500 h. Within this test set-up,it was found that a multi-level chemical pre-treatment gives significantly better adhesion results,in particular at 175°C and 200°C,compared with a pre-treatment by brush or pumice brush. Also,breakdown voltage as well as tracking resistance were investigated. For an application in LED technology,the light reflectivity and white colour stability of the printed circuit board are of major importance,especially when high-power LEDs are used which can generate larger amounts of heat. For this reason,a very high coverage power and an intense white colour with high reflectivity values are essential for white solder masks. These "ultra-white" and largely non-yellowing LPiSM need to be able to withstand specific thermal loads,especially in combination with high-power LED lighting applications. The topic of thermal performance of coatings for electronics will also be discussed in view of printed heatsink paste (HSP) and thermal interface paste (TIP) coatings which are used for a growing number of applications. They are processed at the printed circuit board manufacturing level for thermal-coupling and heat-spreading purposes in various thermal management-sensitive fields,especially in the automotive and LED lighting industries. Besides giving an overview of the principle functionality,it will be discussed what makes these ceramic-filled epoxy-or silicone-based materials special compared to using "thermal greases" and "thermal pads" for heat dissipation purposes.

The symbiotic relationship between solder masks and selective finishes is not new. The soldermask application is one of the key considerations to ensure a successful application of a selective finish. The selective finish is the final chemical step of the PCB manufacturing process,this is when the panels are at their most valuable and are unfortunately not re-workable. Imperfections are not tolerated,even if they are wholly cosmetic. Quality issues often manifest themselves in the form of a ‘ping pong’ conversation between the fabricators,the soldermask suppliers and the selective finish suppliers. Without tangible evidence these discussions are difficult to resolve and the selective finish process is usually regarded as responsible. Soldermasks identified as ‘critical’ in the field,and through testing,have been tested using state of the art technology to assess whether performance markers could be found. This paper will focus on the chemical characteristics and use them to predict or identify potential issues before they occur rather than specifically name ‘critical’ soldermasks. It is also the intention of this paper to address the potential of a soldermask to react to common yield hiking practices like UV bumping and oven curing. It is hoped that this awareness will help fabricators to ensure maximum yields by asking the right questions. ‘Critical’ soldermasks impact all selective finishes. In this paper,practical experience using immersion tin will be used to highlight the relationship between ‘critical’ soldermasks and some of the issues seen in the field. The paper will include a novel approach to identify re-deposited volatiles after the reflow.

There are numerous techniques to singulate printed circuit boards after assembly including break-out,routing,wheel cutting and now laser cutting. Lasers have several desirable advantages such as very narrow kerf widths as well as virtually no dust,no mechanical stress,visual pattern recognition and fast set-up changes. The very narrow kerf width resulting from laser ablation and the very tight tolerance of the cutting path placement allows for more usable space on the panel. However,the energy used in the laser cutting process can also create unwanted products on the cut walls as a result of the direct laser ablation. The question raised often is: What are these products,and how far can the creation of such products be mitigated through variation of the laser cutting process,laser parameters and material handling? This paper discusses the type and quantity of the products found on sidewalls of laser depaneled circuit boards and it quantifies the results through measurements of breakdown voltage,as well as electrical impedance. Further this paper discusses mitigation strategies to prevent or limit the amount of change in surface quality as a result of the laser cutting process. Depending on the final application of the circuit board it may prompt a need for proper specification of the expected results in terms of cut surface quality. This in turn will impact the placement of runs and components during layout. It will assist designers and engineers in defining these parameters sufficiently in order to have a predictable quality of the circuit boards after depaneling.

This paper explores the process of identifying and evaluatingpotential counterfeit parts. The military customer is aware that counterfeit parts are a problem and hascreated Defense Federal Acquisition Regulation Supplement (DFARS) 252.246-7007 to add protection and avoidance of the use of counterfeit parts in military products. Thus,defense subcontract manufacturersneed to understand and assure no counterfeit parts get into any product. This paperprovidesa real example of identifying a counterfeit part and the process taken to resolve the issue. The topics that will be addressed include:
i)Defining what,who,and how of counterfeit parts,
ii) Using an industry analysis tool to understand the counterfeit risk,
iii) Uncovering anomalous electrical behaviors,
iv) Researching the manufacturer’s part markings,
v) Informing management about the potential counterfeit part,
vi) Involving a third party to analyze and test for authenticity,
vii) Expanding the team to address the issue with the customerand distributor,and finally,
viii) Providing lessons learned and suggested future measures for avoidance.

This paper explores the process of identifying and evaluatingpotential counterfeit parts. The military customer is aware that counterfeit parts are a problem and hascreated Defense Federal Acquisition Regulation Supplement (DFARS) 252.246-7007 to add protection and avoidance of the use of counterfeit parts in military products. Thus,defense subcontract manufacturersneed to understand and assure no counterfeit parts get into any product. This paperprovidesa real example of identifying a counterfeit part and the process taken to resolve the issue. The topics that will be addressed include:
i)Defining what,who,and how of counterfeit parts,
ii) Using an industry analysis tool to understand the counterfeit risk,
iii) Uncovering anomalous electrical behaviors,
iv) Researching the manufacturer’s part markings,
v) Informing management about the potential counterfeit part,
vi) Involving a third party to analyze and test for authenticity,
vii) Expanding the team to address the issue with the customerand distributor,and finally,
viii) Providing lessons learned and suggested future measures for avoidance.

With the dramatic increase in connected devices in the IoT era,it is becoming imperative to do much more to ensure the quality of all electronic components,especially for devices in mission-critical applications. In this paper,we will discuss actual use cases where product quality and time-to-quality was dramatically improved through the use of a seamless big data infrastructure. The data infrastructure can collect data from across the global supply chain and analyze that data in near-real-time to quickly identify manufacturing issues than can negatively impact product quality and reliability,greatly reducing test costs and downstream Return Merchandise Authorizations (RMAs). By bringing together manufacturing data from Original Equipment manufacturers (OEMs),system integrators and suppliers,overall time-to-quality for the entire supply chain can be reduced by a month or more,dramatically improving time-to-market and market share for all contributors to the supply chain.

Since the European Directives,RoHS (Restriction of Hazardous Substances) and REACH (Registration,Evaluation,Authorization and Restriction of Chemicals),entered into force in 2006-7,the number of regulated substances continues to grow. REACH adds new substances roughly twice a year,and more substances will be added to RoHS in 2019. While these open-ended regulations represent an ongoing burden for supply chain reporting,some ability to remain ahead of new substance restrictions can be achieved through full material declarations (FMD) specifically the IPC-1752A Class D Standard (the “Standard”),which was developed by the IPC-Association Connecting Electronic Industries. What is important to the supply chain is access to user-friendly,easily accessible or free,fully supported tools that allow suppliers to create and modify XML (Extensible Markup Language) files as specified in the Standard. Some tools will provide enhancements that validate required data entry and provide real-time interactive messages to facilitate the resolution of errors. In addition,validation and auto-population of substance CAS (Chemical Abstract Service) numbers,and Class D weight rollup validation ensure greater success in the acceptance of the declarations in customer systems that automate data gathering and reporting. A good tool should support importing existing IPC-1752A files for editing; this capability reduces the effort to update older declarations and greatly benefits suppliers of a family of products with similar composition. One of the problems with FMDs is the use of “wildcard” non-CAS numbers based on a declarable substance list (DSL). While the substances in different company’s lists tend to have some overlap,no two DSL’s are the same. We provide an understanding of the commonality and differences between representative DSLs,and the ability to configure how much of a non-DSL substance percent is allowed. Case studies are discussed to show how supplier compliance data,can be automatically loaded into the customer’s enterprise compliance system. Finally,we briefly discuss future enhancements and other developments like Once an Article,Always an Article (O5A) that will continue to require IPC standards and supporting tools to evolve.

The Augmented Reality and Virtual Reality market is expected to cross $44 billion by the year 2025 according to various industry experts. This exciting new technology is not exactly new,but has cutting edge potential that can change the way that we live our lives and especially how we do business. While there are many types of hardware and software out in the market,few are looking at addressing manufacturing environments. Due to the various types of “Realities” such as “Virtual Reality”,“Augmented Reality”,“Mixed Reality” and others,we will refer to any type of reality as “XR” where “X” is a variable. For this paper,we will focus only on Augmented Reality and Virtual Reality,while only mentioning some others. Virtual Reality refers to a computer-generated simulation of an environment that can be interacted within a seemingly real or physical way. Augmented Reality refers to viewing the physical environment whose elements are overlaid on top of what you are seeing live. We will discuss how both of these technologies can be used in a manufacturing environment and the key applications we have identified to use these for. In addition to the applications that we have identified,this paper will also cover the market,technology,different types of devices,software,as well as advantages and limitations that exist today

E-textiles,also known as electronic textiles,smart textiles,smart clothing,smart garments,or smart fabrics,are fabrics with electronic components and sensors embedded in them. Key components of e-textiles are the conductive materials to connect different sensors,modules and power supplies to form a body area network (BAN). In their lifetime,e-textiles including the conductive materials may experience many washing and drying laundry cycles,one of the biggest challenges facing the application of e-textiles. Limited data are available on the performance of conductive materials going through the washing and drying cycles. This paper presents studies on the washability of three types of commonly used conductive materials in making e-textiles: conductive yarn,conductive fabric,and conductive ink. Different options to protect the conductive materials are explored,such as water-resistant coating,thermoplastic urethane (TPU) film lamination,and dielectric ink printing. Electrical resistance as a function of laundry cycles is used to characterize the performance of the conductive materials. After the intended laundry cycles,samples were inspected under optical microscope and SEM to provide further insight on the performance of these materials.