The inkjet printing of catalyst Pd ink for selective metallization apply to product antenna on PC/ABS substrate

Abstract

In this paper, a simple and effective method to fabricate conductive antenna metal pattern on plastic substrates PC/ABS (poly(carbonate/Acrylonitrile-Butadiene-Styrene)) is described. This methods involves inkjet printing of copolymer/noble metal nanopartical-based ink on a PC/ABS substrate to create the catalyst site, onto which is subsequently deposited by an electroless plating method, to obtain metal pattern. The main challenge in electroless plating on plastics is to establish a good adhesion between the substrate and metallic film. The PC/ABS substrate was etching by environmental friendly etching solution, after printing, the plastic were immersed in an electroless plating bath to deposition Ni-P pattern. The prepared nickel film thickness is 11µm, which is excellent adhesion of the deposited Ni-P coating to the substrate according to ASTM D3359-78. Finally, a WWAN antenna was formed then test the Radiation characteristics. INTRODUCSIONThe applicaiotn of plastic to function fabrication of electronic devices such as radio-frequency identification (RFID) tag, sensor, antenna, and high precision metal pattern [1][2][3][4] in recent year. However, most of plastic are lack of electric conductivity. Therefore, fabrication metal onto polymer surface is necessary and unavoidable before their application, the technology of deposition metal on a plastic substrate has been tremendous attention. There's many deposition process to formed metal on substrate, such as photolithography and chemical vapor deposition(CVD) [5][6][7][8].Although photolithography could create high resolution metal line, but employ environmentally unfriendly chemicals would formed in the process. Most of substrate can't stand the high temperature in CVD process; both of them are high cost, complexity, and time-consuming. Printing technology has been gradually forward to unconventional, such as microcontact printing (μCP) [13][14][15], and ink-jet print [16][17][18], these print method always combines with electorless deposition, by controlling the position of activation place can selective decide the metal crystals grow and deposition. Electroless deposition is a stable and has been used in many process, this method without high cost equipment, and deposition at low temperature[9-12] is commonly used as a way. The general process of electroless deposition involves preparation of surface, activation by catalyst metal particaleson desire place, and immersed in electroless bath to deposition metal on the substrate, then metallization on the non-conductive substrate. It can also addition metal thickness follow by electroless to fabricate a smooth surface.The main challenge in electroless plating on plastics is to establish a good adhesion between the substrate and metallic film. The general methods for PC/ABS surface etching involves the chromic acid (H 2 CrO 4 ) solution, becaucse the carcinogen chrominum ion (Cr 6+ ) could impose serious environmental threat, more and more environmental friendly etching system has increased and the search for a re...