The drive for miniaturization of both commercial and aerospace/military technologies are not compatible with the current standard United States domestic PCB manufacturing processes at the volumes and lead times needed by OEMs and the Department of Defense. Even in technologies that are relatively widespread in domestic PCB manufacturing such as microvias, there are reliability concerns that prevents designers from exploring such options. The ability to repeatedly and reliably realize fine space and trace down to 25-microns would allow designers to reduce layer count, board footprint, sequential lamination cycles, and the use of stacked microvias at a reduced cycle time and cost. Currently, only offshore PCB manufacturers are close to achieving 25-micron space and trace using modified semi-additive processing (mSAP). The advances in offshore PCB manufacturing coupled with the obsoletion of larger component sizes threaten to disrupt the domestic supply chain as PCB manufacturers struggle to produce the necessary technology with the current process techniques. Extensively developed over the last twelve years, Averatek’s SAP process uses a thin layer of electroless to repeatedly and reliably realize down to 25-micron space and trace. Through a partnership with Calumet Electronics Corporation, a domestic high-volume PCB manufacturer that will act as the beta site for the 1st domestic SAP process, Averatek can now evaluate the integrity of their SAP process on an industrial production level scale. Averatek and Calumet Electronics Corporation will perform extensive qualifications of the use of Averatek SAP process for all subassembly levels of a multilayer board using a systematic approach that ensures traceability through the process from determination of targets, specification limits, quality goals, expectations to potential failures, and evidence of a robust process. The results of the qualification of Averatek SAP process will be used to further commercialize 25-micron space and trace across the domestic PCB industry, strengthening the technological capabilities of American manufacturers, OEMs and the defense supply chain.

The need for increasingly complex electronics combined with the obsolescence of larger component packages is driving innovation to provide alternatives to the traditional subtractive-etch fabrication process to reliably and repeatedly provide circuit layers with 25 micron or finer feature size.  Liquid Metal Ink (LMI™) technology is one of those innovations.

LMI™ allows a very dense thin catalytic seed layer which results in a very dense thin electroless copper layer that can then be used as a base for a much thicker electrolytic copper layer. Because the electroless copper can be so thin (0.1 μm) compared to the electrolytic copper (> 10um) very fine geometries can be defined with a simple flash etching process without risking undercutting the traces. This is the core technology that allows Averatek’s Semi-Additive Process(A-SAP™) to realize very fine feature sizes.

This process is compatible with most printed circuit board (PCB)processes and utilizes conventional PCB equipment. The resulting circuit features can resolve to 25 microns or below, providing a cost-effective solution to complex routing constraints that currently result in multiple lamination, stacked and staggered micro via solutions. LMI™ enables the mixing of a subtractive process with advanced processes such as A-SAP™ in several different ways. This mix and match approach can be used to build a Substrate Like PCB (SLP)and these combinations expand the practicality and performance of the circuit.  These very high-density circuit layers can stand alone or can be combined with layers created by the subtractive etch process that do not require such fine pitch. This combination efficiently results in the reduction of total number of layers and lamination cycles.

A higher manufacturing feasibility results from selecting the best manufacturing methodologies for each portion of the target system. This unique ability to combine standard and advanced processes will leverage the current domestic manufacturing infrastructure while extending capabilities well beyond the next generation interconnect.

The competitive pressures that electronics companies experience today are exceptional, even for an industry accustomed to a relentlessly high rate of innovation. Manufacturers are challenged to keep up with customization (lower volume and higher mix) and globalization. Material shortages and longer lead times means it is harder to maintain inventory. Compliance is also a challenge as more requirements are coming from customers, as well as new demands for example with electronic vehicles. New manufacturing best practices are crucial to meet these challenges.

Data collected from shop-floor drives the MES operation and the material flow. However, the value to this data does not stop there. Digitalization of the operation enables analysis and understanding of what is happening in the factory, why it is happening, and how to improve it. Although the amount of data generated by manufacturing operations is increasing exponentially, only a small portion of it actually gets collected, and an even smaller portion is analyzed in the electronics industry. In the use case presented here, we will demonstrate how manufacturers can benefit from collecting this data and applying analytics.

The biggest challenge with collecting data is turning big data into smart data that provides insight or foresight, can be understood as the point of consumption, and is immediately actionable on the shop-floor. There are three areas in which big data can be useful today in production to take immediate advantage from the amount of data.

The first is to improve our understanding of the process, so that we understand better the physical effects of what we are doing on the process. For example, we know that there might be an influence of the temperature at the reflow soldering in a certain extent, but we do not know if the temperature varies about three to four Kelvin in the reflow soldering process. We do not know whether this already has an impact on the AOI (automated optical inspection) quality or on the soldering quality. The analytics of big data could help us to understand that process better. If we understand our process better, we can buy better equipment and select the parameters more carefully. This could generate ROI in the long-term.

The second area is to improve quality. For example, we could better understand the impact of the incoming quality of our materials, which can reduce our scrap rate on a longer run. In this paper, we will present an example of how to use the data to improve quality in the printing process.

The third area is the most profitable: using the data to improve throughput. Once we have the data in-hand and are able to read the relevant information out of the data, we can judge from the overall quality on the line that the quality in all the single processes is so good, we can reduce the test level without jeopardizing overall quality.

The Vertical Segments of the Electronic Products Manufacturing Industry (Semiconductor, Outsourced System Assembly, and Test, and Printed Circuit Board Assembly) are converging and service offerings are consolidating due to advanced technology adoption and market dynamics. The convergence will cause shifts in the flow of materials across the supply chain as well as the introduction of equipment and processes across the segments. The ability to develop Smart Manufacturing and Industry 4.0 enabling technologies (e.g., big data analytics, artificial intelligence, cloud/edge computing, robotics, automation, IoT) that can be deployed within and between the Vertical Segments is critical. A Smart Manufacturing Technology Working Group (TWG) was formed by International Electronics Manufacturing Initiative (iNEMI) that included thought leaders from across the electronic products manufacturing industry. The TWG published a roadmap that included the situation analysis, critical gaps and key needs to realize Smart Manufacturing.

Robotic soldering is a growing market within the PCB Assembly industry and interest in robotic soldering equipment and applications is increasing every year. This method is more efficient than hand soldering and will aid in alleviating human mistakes. The robotic soldering process is more controlled and repeatable than a selective soldering fountain, and it can increase productivity and profitability. As the industry grows, we’ve found that there is not enough published data regarding this soldering technique. In this paper, we will present how cored wires with different flux percentages will affect robotic soldering performance. All wires used in this project were SAC305 alloy with a 0.020” diameter and3%, 3.5%, 4%,or4.5%of flux.

The electronics industry is still searching for alternative lead-free alloys. Selective soldering requires relatively high solder temperatures to get proper hole filling. Alternative alloys with lower melting temperatures may wet faster and open the process window. These low temperature solders (LTS) are of interest in SMT soldering because of reduced warpage and voiding risks. The question is how these alloys respond in liquid soldering applications. Lower operating temperatures reduce the risk of damaging plastic parts or secondary reflow on mixed technology boards. The preheat temperatures are close to the melting point of the alloy which will make the solder flow easily to the solder destination side of the board. Fluidity of these alloys may change at higher temperatures and it will be interesting to see the impact of the melting range on solidification of the solder.

Other alloys are designed to be compatible with extreme thermal exposure in operating environments such as under-hood automotive, avionics/aerospace and other severe operating environments. Their wetting properties are important to get hole fill at reasonable solder temperatures. This study investigates new alloys and their properties in lead-free selective soldering applications. Does their fluidity influence the wave stability on wettable and non-wettable nozzles? The impact of the solder temperature on hole fill and bridging is tested. A test-board with fine pitch components from 1.00 mm to2.54 mm pitch is used to define the bridging risk.

There are new technologies on the market that make it possible to design very odd-shaped nozzles. De-bridging can be much more efficient with this second generation of non-wettable nozzles in combination with advanced nitrogen-gas nozzles to eliminate bridges. This patented nozzle technology will be compared to the conventional nozzles.

This paper presents results from a joined R&D project between two companies; Automotive Tier-1 and Technology Provider of structural electronics. Key benefits of structural electronics are 3-dimensional shapes, reduced thickness and weight as well as simplified assembly. The purpose of this project has been to evaluate structural electronics for automotive interior use. The car interior application is back-seat-control-panel and the structural electronics solution reduces thickness by 70 % and weight by 50 %. The back-seat-control-panel has been subjected to severe testing based on automotive OEM requirements. Environmental loads have been changing of temperature, combination of high humidity and changing of temperature as well as combination of UV-light and high temperature. None of the components failed during reliability testing.

Electronic components are exposed to impact loadings and mechanical vibrations during assembly, material handling, and transportation. These loadings might affect the fatigue life of solder joints and with decreasing size of packages and solder ball dimensions, it becomes more important to evaluate the reliability of these solder joints. In automotive and harsh industry applications, BGA packages are being widely explored and the reliability of this device-type has been the critical dampening factor in employing them. As a result, there has been an influx of newly doped lead-free solder materials in the market commonly referred as “high reliability alloys”, intended to last long in harsh environments.

A thorough investigation of the influence of solder paste alloy on the fatigue life of solder joints between ball grid arrays and PCB undergoing vibration fatigue test is performed. The test matrix comprises of four different solder materials with traditional SAC305 being the control. Initially, modal analysis was performed on the test boards to identify the natural frequencies.

A sinusoidal vibration test was conducted on the test vehicles placed on electrodynamic shaker. The test boards are excited at their natural frequencies and constant amplitude of acceleration until failure of all BGA packages. A strain gauge was mounted on the board to measure and keep track of the maximum principal strain throughout the test. Weibull analysis is performed to compare the vibration fatigue life of various solder alloys, and failure analysis is performed to study the failure modes. All tests were conducted at room temperature. Keywords: Vibration testing, Modal analysis, Sine dwell, Lead-free alloys