MIDs Made of Deep Drawn Circuitry on. B.Wojakowski, U.Heckmann, U. Klug,

Transcription

1 3D-FlexSys MIDs Made of Deep Drawn Circuitry on Thermoplastic Sheets B.Wojakowski, U.Heckmann, U. Klug, R. Kling

2 Outline Motivation Process Chain PVD-Metallization Deep Drawing Laser Structuring Plating Conclusion Outlook

3 Motivation Problem Usually MID components are manufactured in three dimensional processes. Thus advantages in efficiency of a two dimensional process are sacrificed. Solution o Manufacturing of 3D-MIDs using a combination of a number of standard 2D- procedures. The transition to a 3D shape is done at the end of the process chain

4 Goal Motivation - Deep-drawable MIDs made of thermoplast foil substrates - Cost efficient low vacuum PVD metallization - High speed 2D laser structuring of the metallization to generate stretchable circuitry - Plating of the metallization to increase the conductance

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6 Magnetron sputtering Coarse pre- structuring using a shadow-mask Process Chain PVD-Metallization Shadow-mask outline

7 Connecting layer of 50 nm chromium Process Chain PVD-Metallization Improves adhesion Conductive layer of 1 µm copper Copper Chromium Thermoplast Coating sketch Coated polystyrene

8 Deep Drawing Drawing tool and drawn PS Heating of the substrate Blowing of a primary extrusion Forming by a mechanical tool

9 Deep Drawing 1000 µm Untreated metallization is too rigid to withstand the mechanical stress during deep drawing Cracks Loss of conductivity D i Drawn copper coating on a polystyrene substrate

10 Laser treatment setup Process Chain Laser Structuring LUMERA Rapid 532 nm 12 ps Coherent AVIA 355 nm 20 ns Galvanometric scanner Air bearing stages

11 Laser Structuring 100 µm First approach Simple meander cuts Seen here: Additional removal of surplus material Laser structured copper on PC

12 Laser Structuring 100 µm Small structures are withstanding the mechanical stress of deep drawing Structure widths below 40 µm Polycarbonate Bigger structures crack at the pivot points of the meander Structures conductive on polycarbonate 100 µm Polystyrene

13 Laser Structuring 500 µm Added complexity Computer generated geometry Shortened overall length Works only on polycarbonate 100 µm Laser structured copper on PC

14 Laser Structuring 500 µm Added redundancy Suited to orthogonal stress 80% increase in length achieved Laser structured copper on PC

15 Laser Structuring 1 mm Very complex net structures Added redundancy Suited to orthogonal stress Laser structured copper on Laser structured copper on polycarbonate

16 Laser Structuring 1 mm Very complex net structures Added redundancy Suited to orthogonal stress Works also on polystyrene Laser structured copper on polystyrene

17 Plating Electroless plated copper on polystyrene and ABS Electroless plating Increasing layer thickness to a usable level Curing of very small cracks Possible on polystyrene and ABS substrates t

18 Plating Electro plated copper on polycarbonate Electro-plating Fast growing material thickness Needs full conductivity Works on polycarbonate Tests on polystyrene not concluded yet

19 Conclusion Manufacturing method for MIDs Mostly twodimensional Proof of principle Further improvement necessary

20 Outlook Building a demonstrating application Developing a machine concept Refining the process Developing add-on processes

21 Thank You! Fraunhofer-IST Sensorische sc e Funktionsschichten c te Bienroder Weg 54 E Braunschweig Laser Zentrum Hannover e.v. Mikrotechnik Hollerithallee Hannover Dipl.-Ing. Ulrike Heckmann M. Sc. Bodo Wojakowski Tel.: +49 (531) Tel.: +49 (0) ulrike.heckmann@ist.fraunhofer.de b.wojakowski@lzh.de