Fabrication of Copper Patterns on Polydimethylsiloxane through Laser-Induced Selective Metallization

Abstract

Selective metallization is widely used in the fabrication of conductive circuits and metallized patterns. In this work, a facile approach for the fabrication of copper patterns on polydimethylsiloxane (PDMS) substrates was developed through a 1064 nm pulsed near-infrared (NIR) laser activation and selective metallization. The laser sensitizer of copper hydroxyl phosphate [Cu 2 (OH)PO 4 ] and antimony-doped tin oxide (ATO) were incorporated into PDMS resin to prepared laser direct structuring (LDS) materials, respectively. The physical morphology and chemical composition of PDMS/Cu 2 (OH)PO 4 and PDMS/ATO after 1064 nm pulsed NIR laser activation and metallization characterizations were determined. The laser-irradiated area of the PDMS substrate exhibited catalyst activation, which could trigger an electroless copper plating (ECP) reaction. The obtained copper patterns exhibit strong mechanical adhesion on the PDMS substrate, which reaches class 5B level after an adhesive tape test (ASTM D3359 standard). Moreover, the conductivity of the obtained copper pattern on PDMS/ Cu 2 (OH)PO 4 and PDMS/ATO is around 2.09 × 10 7 and 1.38 × 10 7 Ω −1 •m −1 . This study provides a strategy to fabricate PDMSbased LDS materials for large-scale industrial applications.

Autocatalytic Laser Activator for Both UV and NIR Lasers: Preparation of Circuits on Polymer Substrates by Selective Metallization

“…Also, the copper layers are obtained (Figure c), indicating that MoO 3 is an excellent laser activator that works for both the 355 nm UV laser and 1064 nm NIR laser. As for the parameters of the NIR laser, the best scanning speed and line spacing of the laser beam are 2000 mm/s and 30 μm, respectively, according to our previous report . Also, the optimal laser power and pulse frequency are screened (Figures S2b and c).…”

“…As for the parameters of the NIR laser, the best scanning speed and line spacing of the laser beam are 2000 mm/s and 30 μm, respectively, according to our previous report. 43 Also, the optimal laser power and pulse frequency are screened (Figures S2b and 1c). Note that the maximum power of the NIR laser is 20 W. Figure S4b shows the resistances of each square copper layer; the smallest value appears at 12 W (60%) and 60 kHz.…”

Efficient and Simple Fabrication of High-Strength and High-Conductivity Metallization Patterns on Flexible Polymer Films

“…For laser direct structuring (LDS) technology, the laser sensitizer must be added to the polymer matrix to construct LDS materials. − Significant efforts have been investigated to reveal the relationship between laser-induced activation and metallization. − During the laser activation process, the elemental metal is generated from the laser sensitizer, which acts as a catalyst, which is important to initiate electroless plating. − The arbitrary patterns were fabricated and simultaneously activated during laser irradiation. It should be noted that the LDS technology needs to incorporate a laser sensitizer into the polymer matrix.…”

Laser Direct Structured 3D Circuits on Silicone

“…The basic LDS process has recently been demonstrated on planar cast silicone of moderate flexibility (20−50 hardness on Shore A), using copper hydroxyl phosphate and antimony-doped tin oxide as LDS dopants. 28 study only produced simple 2-dimensional copper patterns with no significant electrical function or deformation capability. Also, the nominal rigidity of the studied silicone is greater than human skin, but the study neglected to perform any mechanical testing on the silicone samples integrated with copper features.…”