scholarly journals Hybrid structural electronics printing by novel dry film stereolithography and laser induced forward transfer

Nano Select ◽  
2021 ◽  
Author(s):  
Asaf Levy ◽  
Gil Bernstein Toker ◽  
Shoshana Winter ◽  
Sharona S. Cohen ◽  
Oleg Ermak ◽  
...  
Keyword(s):  
Forward Transfer ◽  
Structural Electronics ◽  
Dry Film

Whisker Formation in Copper Electroplating

2011 ◽  
Author(s):  
Theresa Han ◽  
Eunin Cho ◽  
Jinwoo Heo ◽  
Seoung Jae Lee
Keyword(s):  
Copper Sulfate ◽  
Surface Stress ◽  
Whisker Formation ◽  
Printed Wiring Boards ◽  
Copper Electroplating ◽  
Cu Electroplating ◽  
Solution Surface ◽  
Dry Film

Abstract In the manufacture of Printed Wiring Boards (PWB), unwelcome structures, such as nodules and whiskers can be formed during copper electroplating with copper sulfate. Copper (Cu) whiskers with lengths of up to a few hundred micrometers can lead to electrical shorts between layers or patterns. In this paper, we document factors that can affect the growth of Cu whiskers; decomposition of additives in the Cu electroplating solution, surface stress, acidic cleaner, and the ingredients of a dry film. Contaminants from outside of the electroplating bath and the ingredients of the dry film were shown as key components in the formation of Cu whiskers.

scholarly journals Subthreshold laser jetting via flow-focusing in laser-induced forward transfer

2018 ◽  
Vol 3 (8) ◽  
Author(s):  
Emre Turkoz ◽  
SeungYeon Kang ◽  
Luc Deike ◽  
Craig B. Arnold
Keyword(s):  
Flow Focusing ◽  
Forward Transfer ◽  
Subthreshold Laser

scholarly journals Carbon Nanotube-Based Composite Filaments for 3D Printing of Structural and Conductive Elements

2021 ◽  
Vol 11 (3) ◽  
pp. 1272
Author(s):  
Bartłomiej Podsiadły ◽  
Piotr Matuszewski ◽  
Andrzej Skalski ◽  
Marcin Słoma
Keyword(s):  
Carbon Nanotubes ◽  
Fused Deposition Modeling ◽  
Supply Voltage ◽  
Acrylonitrile Butadiene Styrene ◽  
Structural Elements ◽  
Filling Fraction ◽  
Fused Deposition ◽  
Structural Electronics ◽  
Measured Sample ◽  
Deposition Modeling

In this publication, we describe the process of fabrication and the analysis of the properties of nanocomposite filaments based on carbon nanotubes and acrylonitrile butadiene styrene (ABS) polymer for fused deposition modeling (FDM) additive manufacturing. Polymer granulate was mixed and extruded with a filling fraction of 0.99, 1.96, 4.76, 9.09 wt.% of CNTs (carbon nanotubes) to fabricate composite filaments with a diameter of 1.75 mm. Detailed mechanical and electrical investigations of printed test samples were performed. The results demonstrate that CNT content has a significant influence on mechanical properties and electrical conductivity of printed samples. Printed samples obtained from high CNT content composites exhibited an improvement in the tensile strength by 12.6%. Measurements of nanocomposites’ electrical properties exhibited non-linear relation between the supply voltage and measured sample resistivity. This effect can be attributed to the semiconductor nature of the CNT functional phase and the occurrence of a tunnelling effect in percolation network. Detailed I–V characteristics related to the amount of CNTs in the composite and the supply voltage influence are also presented. At a constant voltage value, the average resistivity of the printed elements is 2.5 Ωm for 4.76 wt.% CNT and 0.15 Ωm for 9.09 wt.% CNT, respectively. These results demonstrate that ABS/CNT composites are a promising functional material for FDM additive fabrication of structural elements, but also structural electronics and sensors.

scholarly journals Transient Three-Dimensional Flow Field Measurements by Means of 3D µPTV in Drying Poly(Vinyl Acetate)-Methanol Thin Films Subject to Short-Scale Marangoni Instabilities

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1223
Author(s):  
Max Tönsmann ◽  
Philip Scharfer ◽  
Wilhelm Schabel
Keyword(s):  
Flow Field ◽  
Vinyl Acetate ◽  
Three Dimensional ◽  
Field Measurements ◽  
Initial Assessment ◽  
Ambient Conditions ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Short Scale ◽  
Dry Film

Convective Marangoni instabilities in drying polymer films may induce surface deformations, which persist in the dry film, deteriorating product performance. While theoretic stability analyses are abundantly available, experimental data are scarce. We report transient three-dimensional flow field measurements in thin poly(vinyl acetate)-methanol films, drying under ambient conditions with several films exhibiting short-scale Marangoni convection cells. An initial assessment of the upper limit of thermal and solutal Marangoni numbers reveals that the solutal effect is likely to be the dominant cause for the observed instabilities.

scholarly journals Eco-Friendly Lead-Free Solder Paste Printing via Laser-Induced Forward Transfer for the Assembly of Ultra-Fine Pitch Electronic Components

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3353
Author(s):  
Marina Makrygianni ◽  
Filimon Zacharatos ◽  
Kostas Andritsos ◽  
Ioannis Theodorakos ◽  
Dimitris Reppas ◽  
...  
Keyword(s):  
High Resolution ◽  
Form Factors ◽  
Circuit Board ◽  
Lead Free ◽  
Process Conditions ◽  
Solder Paste ◽  
Electronic Components ◽  
Successful Operation ◽  
Fine Pitch ◽  
Forward Transfer

Current challenges in printed circuit board (PCB) assembly require high-resolution deposition of ultra-fine pitch components (<0.3 mm and <60 μm respectively), high throughput and compatibility with flexible substrates, which are poorly met by the conventional deposition techniques (e.g., stencil printing). Laser-Induced Forward Transfer (LIFT) constitutes an excellent alternative for assembly of electronic components: it is fully compatible with lead-free soldering materials and offers high-resolution printing of solder paste bumps (<60 μm) and throughput (up to 10,000 pads/s). In this work, the laser-process conditions which allow control over the transfer of solder paste bumps and arrays, with form factors in line with the features of fine pitch PCBs, are investigated. The study of solder paste as a function of donor/receiver gap confirmed that controllable printing of bumps containing many microparticles is feasible for a gap < 100 μm from a donor layer thickness set at 100 and 150 μm. The transfer of solder bumps with resolution < 100 μm and solder micropatterns on different substrates, including PCB and silver pads, have been achieved. Finally, the successful operation of a LED interconnected to a pin connector bonded to a laser-printed solder micro-pattern was demonstrated.

scholarly journals Ni‐Doped MoS 2 Dry Film Lubricant Life

2020 ◽  
Vol 7 (22) ◽  
pp. 2001109
Author(s):  
Azhar Vellore ◽  
Sergio Romero Garcia ◽  
Nicholas Walters ◽  
Duval A. Johnson ◽  
Andrew Kennett ◽  
...  
Keyword(s):  
Dry Film

Laser induced forward transfer of Ag nanoparticles ink deposition and characterization

2014 ◽  
Vol 297 ◽  
pp. 40-44 ◽  
Author(s):  
M. Makrygianni ◽  
I. Kalpyris ◽  
C. Boutopoulos ◽  
I. Zergioti
Keyword(s):  
Ag Nanoparticles ◽  
Forward Transfer
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