Laser-induced Selective Metal Plating on PP and PC/ABS Polymers Surface

Transcription

1 Laser-induced Selective Metal Plating on PP and PC/ABS Polymers Surface K. Ratautas 1, M. Gedvilas 1, I. Stankevičienė 1, A. Jagminienė 1, E. Norkus 1, N. Li Pira 2, S. Sinopoli 3, G. Račiukaitis 1 1 Center for Physical Sciences and Technology, Vilnius, Lithuania 2 Centro Ricerche Fiat, Orbassano (TO), Italy 3 BioAge srl, Lamezia Terme (CZ), Italy 3-D MID congress 2016 September 28-29, 2016

2 Outline Motivation: Molded interconnect devices Laser direct structuring (LDS) Experimental setup Sheet resistance measurements for plating quality investigations Activation threshold Spatial plating selectivity Summary Selective Surface Activation Induced by Laser (SSAIL) Method Spatial plating selectivity Summary September 2016, The Congress Centrum Würzburg, Würzburg, Germany 2

3 Experimental setup Materials: PP Hostacom CR 1171 G1 + multi-walled Carbon Nano Tubes [CNT] PC/ABS Bayblend T65 XF + multi-walled Carbon Nano Tubes [CNT] Concentration of additives: 2%; 2,5%; 5%; 7,5% by mass. Laser processing: Nanosecond laser: Baltic HP (Ekspla), pulse duration 10 ns Picosecond laser: PL10100 (Ekspla), pulse duration 10 ps Wavelength: 1064 nm; 532 nm. Pulse rep. rate: khz Beam control: Galvo-scanner hurry scan II 14 (Scanlab) Scanning speed up to 3 m/s. Gaussian beam spot radius: μm (1/e 2 ) Electroless plating: Copper sulfate. Ligand: 1) potassium sodium tartrate; 2) ligand X Buffer: sodium hydroxide, sodium carbonate Reducer: formaldehyde September 2016, The Congress Centrum Würzburg, Würzburg, Germany 3

4 Results Nanosecond pulses Picosecond pulses NO ACTIVATION! Measuring sheet resistance Scheme of sheet resistance measurements Using 4 probe method Equipment: Keithley September 2016, The Congress Centrum Würzburg, Würzburg, Germany 4

5 Optimal value of irradiation dose /R s [s sq] 0,1 0,01 1E-3 1E-4 1E-5 1E-6 1E-7 1E-8 1E-9 3 Threshold - melting! 2 1 0,1 W 0,2 W 0,3 W 0,4 W 0,5 W 0,6 W 0,7 W 0,8 W 0,9 W Average 1E-10 Threshold: Threshold: 0.5 J/cm 0, Irradiation dose [J/cm 2 ] September 2016, The Congress Centrum Würzburg, Würzburg, Germany 5

6 Raman analysis of PP D G Raman spectra of PP/carbon additives (a) before, and (b) after laser treatment. 808; 840 cm -1 PP crystalline phase 1166 cm -1 Stretching vibration of C C bond 1329 cm -1 D band, aromatic ring breathing mode 1597 cm -1 G in-plane stretching vibration of aromatic ring 2654 cm -1 2D band 2848 cm -1 CH 2 symmetric 2883 cm -1 CH 3 symmetric 2958 cm -1 CH 3 asymmetric Decrease in 808, 840 and 2883 cm -1 represents disassemble of polymeric structure September 2016, The Congress Centrum Würzburg, Würzburg, Germany 6

7 Raman analysis of PP Raman intensity [cps] D G laser treated untreated Treated Untreated I(D)/I(G) D position cm cm -1 G position cm cm -1 D FWHM 97.3 cm cm -1 G FWHM 95.1 cm cm wavenumber [cm ] Narrowing width of D and G band decrease number of defects Increase of I(D)/I(G) grow in the crystalline cluster size and formation of disordered nanocrystalline structure Positive shift of G clustering A. C. Ferrari et al., Physical Review B 2, 61 (2000) September 2016, The Congress Centrum Würzburg, Würzburg, Germany 7

8 Physics of the activation? Sheet resistance measurement of non metalized surface Concentration of additivities 7.5 % 5 % 2,5 % Laser treatment yes no yes no yes no Sheet Resistance 1.6e5 2.2e7 1.65e5 2.3e7 1.66e5 2.3e7 Results: Does not work with picoseconds Has a sharp threshold of irradiation dose SEM analysis represents threshold as melting Hypothesis: Structural changes? September 2016, The Congress Centrum Würzburg, Würzburg, Germany 8

9 Tartrate vs Ligand X Substitution of ligand increase plating quality and thickness Standard Cu bath Cu bath with special ligand R1 Rs=0.136 Ω / Ligand X 60 o C Ligand X 50 o C Ligand X40 o C NaK tartrate 40 o C Layer thickness [ m] Plating time [min] September 2016, The Congress Centrum Würzburg, Würzburg, Germany 9

10 Selectivity of copper plating Controlling width of lines by changing laser spot size September 2016, The Congress Centrum Würzburg, Würzburg, Germany 10

11 Structuring of inclined surface Spot size enlargement Reduce laser fluence Specimen Platform perpendicular to the beam Laser beam angle of inclination Laser beam Spot size a b 1,0 Above 70% 1,0 conductivity [a.u.] 0,8 0,7 0,6 0,4 0,2 0,0 1 m/s 0,6 m/s 0,2 m/s 1 m/s 0,6 m/s 0,2 m/s Laser fluence [a.u.] 0,8 0,6 0,44 0,4 0,2 0,0 0,0 0,2 0,4 0,44 0,6 0,8 1,0 Fluence [a.u.] , Inclination angle [deg] September 2016, The Congress Centrum Würzburg, Würzburg, Germany 11

12 Summary of LDS LDS for PP, PC/ABS doped with carbon based additives additives works only with nanoseconds laser Laser activation for catalytic plating has a threshold of laser fluence Processing of curved surface up to inclination of 63º is available 3 m/s laser scanning speed is achieved (limited by scanner properties) for PP and PC/ABS Plated lines as narrow as 23 μm can be achieved September 2016, The Congress Centrum Würzburg, Würzburg, Germany

13 Selective Surface Activation Induced by Laser (SSAIL) Laser structuring Activation Rinsing Standard PC/ABS bayblend T65 XF No additives!!! 4 steps process Laser processing Chemical activation Rinsing Electroless plating result Electroless plating September 2016, The Congress Centrum Würzburg, Würzburg, Germany 13

14 Selective Surface Activation Induced by Laser (SSAIL) Standard PC/ABS bayblend T65 High selectiveness No LDS additives!!! September 2016, The Congress Centrum Würzburg, Würzburg, Germany 14

15 Structuring of inclined surface Spot size enlargement Decrease in laser fluence Specimen Laser beam Laser beam Spot size Platform perpendicular to the beam angle of inclination a b 1,0 1,0 conductivity [a.u.] 0,8 0,75 0,7 0,6 0,4 0,2 0,0 1 m/s; m/s; nm; nm; khz 100 khz 10,3 m/s; m/s; ,3 nm; m/s; nm khz nm 50 khz 0,1 m/s; 355 nm 50 khz 0,1 m/s; 532 nm 50 khz Laser fluence [a.u.] 0,6 0,5 0,4 0,2 0,0 59,5 0,2 0,335 0,4 0,5 0,6 0,8 1,0 Fluence [a.u.] , ,8 Inclination angle [deg] September 2016, The Congress Centrum Würzburg, Würzburg, Germany

16 Adhesion (scotch tape test) Irradiation dose [J/cm 2 ] SSAIL PASS TEST 100%!! Fluence [J/cm 2 ] Pulse rep. rate (khz) Wavelength [nm] ; 532; Scanning speed [m/s] September 2016, The Congress Centrum Würzburg, Würzburg, Germany 16

17 Demonstrators September 2016, The Congress Centrum Würzburg, Würzburg, Germany 17

18 Summary of SSAIL PC/ABS Bayblend T65 XF (without any additives) can be selectively metal plated using SSAIL method Processing of curved surface up to inclination of 70º is available 3 m/s laser scanning speed is achieved (limited by scanner properties) Scotch tape test results showed excellent adhesion September 2016, The Congress Centrum Würzburg, Würzburg, Germany 18

19 Thank you for attention Contact info: Karolis Ratautas Department of Laser Technology Center for Physical Sciences & Technology (CPST) Savanoriu Ave. 231, LT-02300, Vilnius, Lithuania mob.ph Acknowledgment: Hub of Application Laboratories for Equipment Assessment in Laser Based Manufacturing This research is funded by the European Commission fund under Collaborative Project of 7 th Framework Programme, APPOLO Project FP7-No September 2016, The Congress Centrum Würzburg, Würzburg, Germany 19