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Let’s talk about multilayer PCB manufacturing*

* but without copper, etching, FR-4, lamination, drilling, silver nanoparticles, inks and pastes, screen printing, inkjet, laser sintering, soldering, ...

3D printed electronic circuits from fusible alloys

Liubomir Bezgan, Marcin SłomaMicrotechnology and Nanotechnology Division

Functional heterophase materials for structural electronics, First TEAM/2016-1/7

42nd International Microelectronics and Packaging IMAPS Poland 2018 ConferenceSeptember 23-26 2018 Gliwice

3PRINTED ELECTRONICS

A new electronics technology utilizing printing methods to fabricate electrical devices on various substrates. Common printing techniques and other low-cost coating techniques are used such as screen printing, ink-jet, roll-to-roll techniques or spray coating. Printed electronics will not replace traditional PCBs or ICs but will fill the need for low-cost, low-performance electronics like flexible displays, smart labels, active clothing or large area photovoltaics. It is suitable for printing on most elastic substrates i.e. polymer foils, paper or textiles, but also ceramics, glass or even walls, casings and other rigid structures.

4STRUCTURAL ELECTRONICS

Electrical and electronic components/circuits acting as a construction elements, casings or other type of protective dumb structures (i.e. vehicle bodies), embedded inside the volume of element or conformally placed on the surface. Due to possibility of enhancing products functionality, lowering production cost, or providing fabrication of consumer tailored devices, structural electronics is an interesting technology for aerospace and military applications, consumer electronics, automotive industry and civil engineering.

5ADDITIVE MANUFACTURING

Another disruptive manufacturing technique, is additive manufacturing (3D printing), allowing design of complex geometries, permit fast and flexible design changes, prompt development of mass customisation, and provides a low-risk entrance to market for innovations. The implementation of such modern technologies allows to change the approach to production and prototyping, by quick validation of the concept, or production of short series, and at the same time cost and waste reduction.

6ADDITIVE MANUFACTURING

Combining the advantages of printed electronics and additive manufacturing we should expect similar effects with structural electronics, but at this time the materials selection for 3D printed structural electronics is severely limited.- plastics: ABS, PLA, PC, PPSU, PMMA, …- fotosensitive resins, - metal powders for high temperature sintering and melting: Ti, Al, Cr-Co, INOX, ...- ceramics: SiO2, Al2O3, ZrO2, ...

- glass, concrete, paper, wax, …- sugar, chocolate, dough, caramel, ...…- low temperature melting alloys for construction elements (Zn, Al, ...)

7ADDITIVE MANUFACTURING

Fused Deposition Modelling

Y X

Z

Filament Reel

Feeding rolls

HeaterThermal insulation

Temperature sensors

Dispensing nozzleSupport table

X-Y movement

Z movement

83D PRINTED STRUCTURAL ELECTRONICS

„Functional heterophase materials for structural electronics”, First TEAM/2016-1/7.

The main objective of this project is to design, fabricate and characterize a group of composite materials with tailored physical properties for additive manufacturing (3D printing) of structural electronics.

Research will be conducted taking into account final application of elaborated materials in Fussed Deposition Modeling, Direct Write, Selective Laser Sintering, PolyJet and Aerosol Jet Printing.

93D PRINTED STRUCTURAL ELECTRONICS

A new idea?

103D PRINTED STRUCTURAL ELECTRONICS

A new idea?

113D PRINTED STRUCTURAL ELECTRONICS

A new idea?

123D PRINTED PATHS AND CIRCUITS

The goal was to evaluate the use of new material for FDM technique, for novel concept of electronic circuits fabrication with additive technology. Low temperature melting alloys (fusible alloys) are used for Fused Deposition Modelling of metals (FDMm) on polymer 3D printed substrates.

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133D PRINTED PATHS AND CIRCUITS

The goal was to evaluate the use of new material for FDM technique, for novel concept of electronic circuits fabrication with additive technology. Low temperature melting alloys (fusible alloys) are used for Fused Deposition Modelling of metals (FDMm) on polymer 3D printed substrates.

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143D PRINTED PATHS

Substrate preparation- FDM technique- ABS: infill 40% and 70%

153D PRINTED PATHS

Paths depositionManual deposition with the nozzle fixedto heating iron and hot-air.

Two types of soldering alloys were used- Sn60Pb40- Sn99Ag0,3Cu0,7

163D PRINTED PATHS

Paths depositionAdhesion and wetting

SnPb SnAgCu

flux no fluxDue to the formation of buffer layer (flux) it was impossible to obtain athesion using the flux-core solder.Without flux the both solder alloys exhibited proper adhesion to the ABS substrate.

173D PRINTED PATHS

Paths depositionManual deposition of the solder alloys was comparable to automated FDM process.In all combination of the heat source (iron, hot-air) and materials (SnPb, SnAgCu) continuous metal alloy paths were deposited with proper adhesion to the substrate.Due to the poor wetting of the substrate, the obtained paths did not have uniform thickness.

183D PRINTED PATHS

Paths depositionTo deal with the uniform thickness problem, we have proposed deposition of the metal alloy in to the specially prepared groves, fabricated in the 3D printed substrate. In both cases (triangular and rectangular shaped groves) we were able to obtain uniform cross section of the path on the entire length, resulting in repeatable resistance of the printed paths.

193D PRINTED PATHS

Paths depositionDue to the thermal limitation of the substrate, fusible alloys deposition parameters needs to be controlled. High temperature of the fused solder can negatively affect polymer substrate if the deposition speed is too slow or the process is repeated several times. The solution for such problem can be heated table or heated chamber of the 3D printer.

203D PRINTED CIRCUIT

Circuit fabricationFor the demonstration of the elaborated techique a simple bistable multivibrator was fabricated, with discrete THT components.

213D PRINTED CIRCUIT

Circuit fabricationFor the demonstration of the elaborated techique a simple bistable multivibrator was fabricated, with discrete THT components.

CAD model 40% infill 70% infill

223D PRINTED CIRCUIT

Circuit fabricationFor the demonstration of the elaborated techique a simple bistable multivibrator was fabricated, with discrete THT components.

233D PRINTED CIRCUIT

Advantages:- simultaneous fabrication of polymer substrate and metal paths in one process with one printer- multilayered and embedded circuits fabrication- soldering process can be performed with the same device- vast range of solder materialsDisadvantages:- high resolution paths are problematic- difficulties with some types of integrated circuits (BGA, Flip-Chip, high density QFP)- inferior mechanical properties of substrates (compared with FR-4)

243D PRINTED CIRCUIT

Future perspectives- 3D substrates, curved, non-flat- multilayer circuit boards- embedded structural circuits- fully operational equipment- process automatisation- detailed study of the properties

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42nd International Microelectronics and Packaging IMAPS Poland 2018 ConferenceSeptember 23-26 2018 Gliwice

Thank you for keeping attention

The „Functional heterophase materials for structural electronics” project is carried out within the First TEAM/2016-1/7 programme of

the Foundation for Polish Science co-financed by the European Union under the European Regional Development Fundwww.weles.info