Process Capability of Aerosol-Jet Additive Processes for Long-Runs Up to 10-Hours

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Pradeep Lall ◽  
Amrit Abrol ◽  
Nakul Kothari ◽  
Benjamin Leever ◽  
Scott Miller
Keyword(s):  
Mechanical Properties ◽  
Process Parameters ◽  
Process Capability ◽  
High Volume ◽  
Process Efficiency ◽  
Shear Load ◽  
Additive Processes ◽  
Sintering Time ◽  
Load To Failure ◽  
Aerosol Jet Printing

Abstract Traditionally, printed circuit assemblies have been fabricated through a combination of imaging and plating-based subtractive processes involving the use of photo-exposure followed by baths for plating and etching in order to form the necessary circuitry on rigid and flexible laminates. The emergence of a number of additive technologies presents an opportunity for the development of processes for manufacturing of flexible substrates by utilizing mainstream additive processes. Aerosol-jet printing is capable of printing lines and spaces below 10 μm in width. The aerosol-jet system also supports a wide variety of materials, including nanoparticle inks, screen-printing pastes, conductive polymers, insulators, adhesives, and biological matter. The adoption of additive manufacturing for high-volume commercial fabrication requires an understanding of the print consistency and electrical mechanical properties. Little literature that addresses the effect of varying sintering time and temperature on the shear strength and resistivity of the printed lines exists. In this study, the effect of process parameters on the resultant line consistency and mechanical and electrical properties has been studied. Print process parameters studied include sheath rate, mass flow rate, nozzle size, substrate temperature, and chiller temperature. Properties include resistance and shear load to failure of the printed electrical line as a function of varying sintering time and temperature. The aerosol-jet machine has been used to print interconnects. Printed samples have been exposed to different sintering times and temperatures. The resistance and shear load to failure of the printed lines have been measured. The underlying physics of the resultant trend was then investigated using elemental analysis and scanning electron microscopy. The effect of line consistency drift over prolonged runtimes has been measured for up to 10 h of runtime. The printing process efficiency has been gaged as a function of the process capability index (Cpk) and process capability ratio (Cp). Printed samples were studied offline utilizing optical profilometry in order to analyze the consistency within the line width, height, and resistance, and shear load to study the variance in electrical and mechanical properties over time.

Process Capability of Aerosol-Jet Additive Processes for Long-Runs up to 10-Hours

2019 ◽  
Author(s):  
Pradeep Lall ◽  
Amrit Abrol ◽  
Nakul Kothari ◽  
Ben Leever ◽  
Scott Miller
Keyword(s):  
Mechanical Properties ◽  
Process Parameters ◽  
Process Capability ◽  
High Volume ◽  
Process Efficiency ◽  
Shear Load ◽  
Additive Processes ◽  
Sintering Time ◽  
Load To Failure ◽  
Aerosol Jet Printing

Abstract Traditionally, the printed circuit assemblies have been fabricated through a combination of imaging and plating based subtractive processes involving use of photo-exposure followed by baths for plating and etching to form the needed circuitry on rigid and flexible laminates. Additive electronics is finding applications for fabrication of IoT sensors. The emergence of a number of additive technologies poses an opportunity for the development of processes for manufacture of flexible substrates using mainstream additive processes, which are now commercially available. Aerosol-Jet printing has shown the capability for printing lines and spaces below 10 μm in width. The Aerosol-Jet system supports a wide variety of materials, including nanoparticle inks and screen-printing pastes, conductive polymers, insulators, adhesives, and even biological matter. The adoption of additive manufacturing for high-volume commercial fabrication requires an understanding of the print consistency, electrical and mechanical properties. Little literature exists that addresses the effect of varying sintering time and temperature on the shear strength and resistivity of the printed lines. In this study, the effect of process parameters on the resultant line-consistency, mechanical and electrical properties has been studied. Print process parameters studied include the sheath rate, mass flow rate, nozzle size, substrate temperature and chiller temperature. Properties include resistance and shear load to failure of the printed electrical line as a function of varying sintering time and varying sintering temperature. Aerosol-Jet machine has been used to print interconnects. Printed samples have been exposed to different sintering times and temperatures. The resistance and shear load to failure of the printed lines has been measured. The underlying physics of the resultant trend was then investigated using elemental analysis and SEM. The effect of line-consistency driftover prolonged runtimes has been measured for up to 10-hours of runtime. Printing process efficiency has been gauged a function of process capability index (Cpk) and process capability ratio (Cp). Printed samples were studied offline using optical Profilometry to analyze the consistency within the line width, line height, line resistance and shear load to study the variance in the electrical and mechanical properties over time.

Effect of Process Parameters on Aerosol Jet Printing of Multi-Layer Circuitry

2019 ◽  
Author(s):  
Pradeep Lall ◽  
Kartik Goyal ◽  
Nakul Kothari ◽  
Ben Leever ◽  
Scott Miller
Keyword(s):  
Process Parameters ◽  
Printed Circuit Board ◽  
Process Capability ◽  
Dimensional Accuracy ◽  
High Viscosity ◽  
Circuit Board ◽  
Process Efficiency ◽  
Jet Printing ◽  
Aerosol Jet Printing ◽  
Pneumatic Atomizer

Abstract Printing technologies such as Aerosol Jet provides the freedom of miniaturizing interconnects and producing fine pitch components. Aerosol Jet, a direct printing technique replaces the traditional steps of manufacturing a printed circuit board such as lithography or etching, which are quite expensive, and further allowing the circuits to be fabricated onto all kinds of substrates. Wide impact areas range from healthcare to wearables to future automotive applications. The aerosol jet printer from Optomec utilized in this study, consists of two types of atomizers depending on ink viscosity. One is Ultrasonic Atomizer which supports ink with viscosity range of 1–5cP, and another is Pneumatic Atomizer with large range of suitable viscosity 1–1000cP. This paper focuses on utilizing the aerosol jet printing using both the atomizers to develop process parameters to be able to successfully print bi-material, multi-layer circuitry. The insulating material between two conductive lines used in the paper is of very high viscosity of 350cP, suitable for Pneumatic atomizer and Silver Nano-particle ink with the viscosity suitable for Ultrasonic atomizer as a conductive ink. A statistical modeling approach is presented to predict the attributes such as micro-via diameter before starting the print process, enabling us to pre-adjust the dimensions in CAD for the desired output. Process parameters to obtain a fine print with good electrical properties and better dimensional accuracy are developed. Importance of pre-cleaning the substrate is discussed, in addition to the printing process efficiency gauged as a function of process capability index and process capability ratio.

Development of Process-Recipes for Multi-Layer Circuitry Printing With Z-Axis Interconnects Using Aerosol-Jet Nanoparticle Ink

2020 ◽  
Author(s):  
Pradeep Lall ◽  
Jinesh Narangaparambil ◽  
Ved Soni ◽  
Scott Miller
Keyword(s):  
Flexible Electronics ◽  
Flow Line ◽  
Unit Length ◽  
Scale Up ◽  
Single Layer ◽  
Consumer Electronics ◽  
Shear Load ◽  
Load To Failure ◽  
Jet Printing ◽  
Aerosol Jet Printing

Abstract Flexible electronics is a rapid emerging trend in consumer-electronics with ever-increasing applications showing feasibility of functionality with flexibility. Aerosol Jet printing technology has gained rapid acceptance for additive printing owing to non-contact deposition and ability to print on non-planar surfaces. Prior work on aerosol-jet print processes primarily focuses on single-layer printing, taking into account different parameters such as mass flow, line width, sintering conditions, and overspray. Flexible PCBs in complex applications are envisioned to be multi-layered, involving stacking of interconnections and connection between successive layers through use of z-axis connections. Aerosol-jet printing method allows the printing of interconnections with a number of inks including silver, copper, and carbon with fine lines and spaces in neighborhood of 10μm. Process recipes for manufacturing multilayer circuits and system scale-up methods are required. The objective of the paper is to establish process-recipes for z-axis interconnects and quantify process variability with Aerosol-jet print process needed for high volume scale-up. Conductive interconnects have been printed using the ultrasonic atomizer and the interlayer dielectrics have been printed using the pneumatic atomizer. The effect of thermal sintering on the performance of the printed circuits has been quantified through measurements of interconnect resistance and shear load to failure. This paper explores the printing of multi-layer upto 8 conductive layers. Sintering profile for lower resistance per unit length and higher shear load to failure was tested.

Optimization of Process Parameters of Al-10% Cu Compacts through Powder Metallurgy

2015 ◽  
Vol 813-814 ◽  
pp. 603-607
Author(s):  
T. Pravin ◽  
M. Sadhasivam ◽  
S. Raghuraman
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Process Parameters ◽  
Weight Ratio ◽  
High Strength ◽  
Process Efficiency ◽  
Light Weight ◽  
Optimization Of Process Parameters ◽  
Maximum Process ◽  
Controlled Porosity

Powder Metallurgy (P/M) is a manufacturing process in which powders are compacted in a die to attain the final product. P/M has certain unique advantage like controlled porosity, High Strength to weight ratio. Aluminium (Al) is a light weight material, but pure Al does not possess a good strength. To achieve the strength, Copper (Cu) powders are blended at required proportions. Al along with Cu shows good mechanical properties. An attempt is made to optimize the process parameter of Al – 10% Cu powder to attain maximum process efficiency. Here optimization is done by Taghuchi’s method.

Additively Printed Multilayer Substrate Using Aerosol-Jet Technique

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Pradeep Lall ◽  
Kartik Goyal ◽  
Nakul Kothari ◽  
Benjamin Leever ◽  
Scott Miller
Keyword(s):  
Process Parameters ◽  
Computer Aided Design ◽  
Process Capability ◽  
Dimensional Accuracy ◽  
High Viscosity ◽  
Process Efficiency ◽  
Low Viscosity ◽  
Aided Design ◽  
Print Process ◽  
Pneumatic Atomizer

Abstract Printing technologies, such as aerosol-jet, open possibilities of miniaturizing interconnects and designing circuits on nonplanar surfaces. Aerosol-jet is a direct-printing technique that provides an alternative manufacturing option to traditional subtractive methods that entail lithography or etching. Additionally, the aerosol-jet technique allows the circuits fabrication using noncontact method. Wide impact areas range from healthcare to wearables to future automotive applications. The aerosol-jet printer from Optomec utilized in this study consists of two types of atomizers, depending on ink viscosity. The ultrasonic atomizer, supports ink with a viscosity range of 1–5 cP, and the pneumatic atomizer that has a larger range of 1–1000 cP. This paper focuses on utilizing the aerosol-jet technique, using both atomizers to develop process parameters, in order to successfully print bimaterial, multilayer circuitry. The insulating material between two conductive lines used in the paper is of very high viscosity of 350 cP, which is suitable for the pneumatic atomizer and silver nanoparticle ink with comparatively low viscosity of 30 cP for the ultrasonic atomizer as a conductive ink. This paper also presents a statistical modeling approach that predicts line attributes, including microvia-diameter, before starting the print process, enabling us to pre-adjust the dimensions in computer-aided design for the desired output. Process parameters can obtain a fine print with satisfactory electrical properties, which develops improved dimensional accuracy. The importance of precleaning the substrate in addition to the printing process efficiency gaged as a function of process capability index and process capability ratio is also presented.

Process-Consistency in Additive Printed Multilayer Substrates With Offset-Vias Using Aerosol Jet Technology

2020 ◽  
Author(s):  
Pradeep Lall ◽  
Kartik Goyal ◽  
Scott Miller
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Process Parameters ◽  
Flow Rate ◽  
Printed Electronics ◽  
Mechanical Performance ◽  
High Volume ◽  
Electrical Performance ◽  
Load To Failure ◽  
High Volume Production

Abstract The transition of additive printed electronics into high-volume production requires process consistency to allow quality control of the manufactured product. Process recipes are needed for multilayer substrates with z-axis interconnects in order to enable complex systems. In this paper, process recipes have been developed through fundamental studies of the interactions between the process parameters and the mechanical-electrical performance achieved for multilayer substrates. The study reported in this paper focuses on printed vias also known as donut vias. Aerosol jet process parameters studied include carrier mass flow rate, sheath mass flow rate, exhaust mass flow rate, print speed, number of passes, sintering time and temperature, uv-intensity for uv-cure, and standoff height. The electrical performance has been quantified through the measurements of resistance. The mechanical performance has been quantified through measurement of shear load-to-failure. The effect of sequential build-up on the mechanical-electrical properties vs process parameters have been quantified for up tp 8-layers designs. The performance of 5-layer and 8-layer additively printed substrate designs and effect of multiple vias has been compared to assess process consistency.

Ultrasonic Torsion Welding of Aging Resistant Al/CFRP Joints - Concepts, Mechanical and Microstructural Properties

2017 ◽  
Vol 742 ◽  
pp. 395-400 ◽  
Author(s):  
Florian Staab ◽  
Frank Balle ◽  
Johannes Born
Keyword(s):  
Mechanical Properties ◽  
Process Parameters ◽  
Materials Science ◽  
Dissimilar Materials ◽  
Material Design ◽  
Ultrasonic Welding ◽  
Fatigue Properties ◽  
Aviation Industry ◽  
Efficient Design ◽  
Engineering Structures

Multi-material-design offers high potential for weight saving and optimization of engineering structures but inherits challenges as well, especially robust joining methods and long-term properties of hybrid structures. The application of joining techniques like ultrasonic welding allows a very efficient design of multi-material-components to enable further use of material specific advantages and are superior concerning mechanical properties.The Institute of Materials Science and Engineering of the University of Kaiserslautern (WKK) has a long-time experience on ultrasonic welding of dissimilar materials, for example different kinds of CFRP, light metals, steels or even glasses and ceramics. The mechanical properties are mostly optimized by using ideal process parameters, determined through statistical test planning methods.This gained knowledge is now to be transferred to application in aviation industry in cooperation with CTC GmbH and Airbus Operations GmbH. Therefore aircraft-related materials are joined by ultrasonic welding. The applied process parameters are recorded and analyzed in detail to be interlinked with the resulting mechanical properties of the hybrid joints. Aircraft derived multi-material demonstrators will be designed, manufactured and characterized with respect to their monotonic and fatigue properties as well as their resistance to aging.

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