Proceedings of the
9th International Conference of Asian Society for Precision Engineering and Nanotechnology (ASPEN2022)
15 – 18 November 2022, Singapore

Laser-Induced Metallization for Fabrication of Circuits on the 3D Surface of Devices

Min-Chieh Chou1, Tune-Hune Kao1, Meng-Chi Huang1 and Ta-Hsin Chou2,a

1Mechanical and Mechatronics Systems Research Laboratories, Industrial Technology Research Institute, Chutung, Hsinchu, Taiwan, ROC

2Office of Strategy and R&D Planning, Industrial Technology Research Institute, Chutung, Hsinchu, Taiwan, ROC


With the rapid development of technology, the volume of electronic products is getting smaller and smaller, but the functions are gradually increasing. 3D structural electronics technology that can integrate electronic circuits onto structural components has become an inevitable trend. Laser direct structuring (LDS) is a quite mature 3D surface circuit process, but it is only suitable for special plastic injection molding materials. Therefore, it can not be applied to 3D printing materials or other non-injection molding materials, nor can it be used to make multi-layer circuits. A novel laser-induced metallization (LIM) technique has been developed to fabricate circuits directly on the 3D surface of most objects. The objects can be made of plastic, metal, glass or ceramic. A special laser-activatable solution is first sprayed on top of the surface of the object, followed by laser structuring and electroless copper plating. The LIM process can be repeated layer by layer to realize the idea of 3D multi-layer circuits. The minimum linewidth of the LIM-3D circuit is strongly dependent on the spot&size of the focused laser. When the spot size of the laser is 38 µm and the object is plastic, the minimum linewidth patterned by laser is about 40 um. After copper electrodeless plating, the line width will slightly widened. Relatively, when the focused spot size is 16 um, and the object material is ceramics such as alumina, perovskite, etc., the minimum linewidth is about 15 um. This study applies LIM-3D circuit technology to 3D ceramic circuit board for CMOS image sensor(CIS) probe card, tactile sensor on humanoid robot finger, 2G/3G/4G all-in-one compact antenna and multi-layer NFC antenna on mobile phone case. Unlike traditionally all circuits must be fabricated on a flat substrate, in the future, LIM-3D circuit technology combined with 3D component die-bonding technology can open up new opportunities for the development of 3D structured electronics.

Keywords: Laser Induced Metallization, 3D structured electronics, 3D multi-layer circuits, Antenna, CIS probe card

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