3D sensing for direct write error characterization for aerosol jet printing

Author(s):  
Rajesh Ramamurthy ◽  
Harry Chiu ◽  
Kevin G. Harding ◽  
Robert Tait
Author(s):  
Hongyue Sun ◽  
Kan Wang ◽  
Yifu Li ◽  
Chuck Zhang ◽  
Ran Jin

Aerosol jet printing (AJP) is a direct write technology that enables fabrication of flexible, fine scale printed electronics on conformal substrates. AJP does not require the time consuming mask and postpatterning processes compared with traditional electronics manufacturing techniques. Thus, the cycle time can be dramatically reduced, and highly personalized designs of electronics can be realized. AJP has been successfully applied to a variety of industries, with different combinations of inks and substrates. However, the quality of the printed electronics, such as resistance, is not able to be measured online. On the other hand, the microscopic image sensors are widely used for printed circuit boards (PCBs) quality quantification and inspection. In this paper, two widely used quality variables of printed electronics, resistance and overspray, will be jointly modeled based on microscopic images for fast quality assessment. Augmented quantitative and qualitative (AUGQQ) models are proposed to use features of microscopic images taken at different locations on the printed electronics as input variables, and resistance and overspray as output variables. The association of resistance and overspray can be investigated through the AUGQQ models formulation. A case study for fabricating silver lines with Optomec® aerosol jet system is used to evaluate the model performance. The proposed AUGQQ models can help assess the printed electronics quality and identify important image features in a timely manner.


2014 ◽  
Vol 2014 (1) ◽  
pp. 000893-000897 ◽  
Author(s):  
Tim Eastman ◽  
Adam Cook

For low volume, high value microelectronic applications reducing cost and time to initial production parts in Low Temperature Cofired Ceramics (LTCC) play a big part in customer satisfaction. Using Direct Write Electronics (DWE) for conductor printing and other structures has the potential to reduce time to production through elimination of intermediate tooling and to reduce waste by applying expensive materials only where they are needed. Additional benefits may be realized by using DWE: wire bonds may be replaced by dispensed conductors; individual layers and parts may be uniquely labeled at the time of printing to improve traceability of product throughout the line and reducing manufacturing errors. This paper investigates using engineered fluid dispensing to print interior and exterior conductors on a demonstration Multi-Chip Module (MCM). Industry standard materials and processes are used to form individual layers of unfired LTCC tape, as well as the forming and filling of interlayer connecting vias with conductive thick film paste. Conductor patterns on each layer are created by dispensing modified Au conductor paste with a commercial three-axis machine with a fine-tipped dispensing pump. Standard processes for collation, lamination, and sintering were followed by aerosol jet printing of Ag ink with a commercial print head mounted on a custom, 6-axis positioning gantry to form wire bond replacements, part identification and individualized markings. Resultant parts are tested for electrical functionality and cross sections are compared to in-progress build photos and line measurements to study the effect of the new printing method vs. structures produced with standard conductor printing processes.


Author(s):  
Andrew J. Capel ◽  
Matthew A. A. Smith ◽  
Silvia Taccola ◽  
Maria Pardo-Figuerez ◽  
Rowan P. Rimington ◽  
...  

Digitally driven manufacturing technologies such as aerosol jet printing (AJP) can make a significant contribution to enabling new capabilities in the field of tissue engineering disease modeling and drug screening. AJP is an emerging non-contact and mask-less printing process which has distinct advantages over other patterning technologies as it offers versatile, high-resolution, direct-write deposition of a variety of materials on planar and non-planar surfaces. This research demonstrates the ability of AJP to print digitally controlled patterns that influence neuronal guidance. These consist of patterned poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) tracks on both glass and poly(potassium 3-sulfopropyl methacrylate) (PKSPMA) coated glass surfaces, promoting selective adhesion of SH-SY5Y neuroblastoma cells. The cell attractive patterns had a maximum height ≥0.2 μm, width and half height ≥15 μm, Ra = 3.5 nm, and RMS = 4.1. The developed biocompatible PEDOT:PSS ink was shown to promote adhesion, growth and differentiation of SH-SY5Y neuronal cells. SH-SY5Y cells cultured directly onto these features exhibited increased nuclei and neuronal alignment on both substrates. In addition, the cell adhesion to the substrate was selective when cultured onto the PKSPMA surfaces resulting in a highly organized neural pattern. This demonstrated the ability to rapidly and flexibly realize intricate and accurate cell patterns by a computer controlled process.


2021 ◽  
Vol 48 ◽  
pp. 101264
Author(s):  
Haining Zhang ◽  
Joon Phil Choi ◽  
Seung Ki Moon ◽  
Teck Hui Ngo

Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 220
Author(s):  
Mahmuda Akter Monne ◽  
Chandan Qumar Howlader ◽  
Bhagyashree Mishra ◽  
Maggie Yihong Chen

Polyvinyl Alcohol (PVA) is a promising polymer due to its high solubility with water, availability in low molecular weight, having short polymer chain, and cost-effectiveness in processing. Printed technology is gaining popularity to utilize processible solution materials at low/room temperature. This work demonstrates the synthesis of PVA solution for 2.5% w/w, 4.5% w/w, 6.5% w/w, 8.5% w/w and 10.5% w/w aqueous solution was formulated. Then the properties of the ink, such as viscosity, contact angle, surface tension, and printability by inkjet and aerosol jet printing, were investigated. The wettability of the ink was investigated on flexible (Kapton) and non-flexible (Silicon) substrates. Both were identified as suitable substrates for all concentrations of PVA. Additionally, we have shown aerosol jet printing (AJP) and inkjet printing (IJP) can produce multi-layer PVA structures. Finally, we have demonstrated the use of PVA as sacrificial material for micro-electro-mechanical-system (MEMS) device fabrication. The dielectric constant of printed PVA is 168 at 100 kHz, which shows an excellent candidate material for printed or traditional transistor fabrication.


2021 ◽  
pp. 102325
Author(s):  
D.R. Hines ◽  
Y. Gu ◽  
A.A. Martin ◽  
P. Li ◽  
J. Fleischer ◽  
...  

Author(s):  
Roozbeh (Ross) Salary ◽  
Jack P. Lombardi ◽  
Prahalad K. Rao ◽  
Mark D. Poliks

The goal of this research is online monitoring of functional electrical properties, e.g., resistance, of electronic devices made using aerosol jet printing (AJP) additive manufacturing (AM) process. In pursuit of this goal, the objective is to recover the cross-sectional profile of AJP-deposited electronic traces (called lines) through shape-from-shading (SfS) analysis of their online images. The aim is to use the SfS-derived cross-sectional profiles to predict the electrical resistance of the lines. An accurate characterization of the cross section is essential for monitoring the device resistance and other functional properties. For instance, as per Ohm’s law, the electrical resistance of a conductor is inversely proportional to its cross-sectional area (CSA). The central hypothesis is that the electrical resistance of an AJP-deposited line estimated online and in situ from its SfS-derived cross-sectional area is within 20% of its offline measurement. To test this hypothesis, silver nanoparticle lines were deposited using an Optomec AJ-300 printer at varying sheath gas flow rate (ShGFR) conditions. The four-point probes method, known as Kelvin sensing, was used to measure the resistance of the printed structures offline. Images of the lines were acquired online using a charge-coupled device (CCD) camera mounted coaxial to the deposition nozzle of the printer. To recover the cross-sectional profiles from the online images, three different SfS techniques were tested: Horn’s method, Pentland’s method, and Shah’s method. Optical profilometry was used to validate the SfS cross section estimates. Shah’s method was found to have the highest fidelity among the three SfS approaches tested. Line resistance was predicted as a function of ShGFR based on the SfS-estimates of line cross section using Shah’s method. The online SfS-derived line resistance was found to be within 20% of offline resistance measurements done using the Kelvin sensing technique.


2018 ◽  
Vol 3 (3) ◽  
pp. 035002 ◽  
Author(s):  
Ethan B Secor

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