Direct manufacturing of customized end-use electronic products is becoming an emerging trend of additive manufacturing (AM). This highly demands the evolution of the conventional AM processes from simply building single-material parts to simultaneously delivering complex structures and end-use functionalities. In this work, we propose a novel hybrid additive manufacturing solution that combines stereolithography (SLA) three-dimensional (3D) printing and laser-activated electroless plating for the manufacture of 3D fully functional electronic products. With our newly developed functional SLA resin that can be 3D printed, laser-activated, and thereafter selectively metalized, high-resolution circuitry can be free-formly patterned on 3D structures. In virtue of high-performance electrical materials, this technology is capable of creating not only 3D direct-current (DC) electronics but also 3D high-frequency devices like microwave/millimeter-wave antennas, which cannot be fabricated via traditional printed circuit board (PCB) technology and not even by most AM processes. This study represents a significant advance in additive manufacturing technologies, and more importantly offers a unique opportunity for the mass customization of fully functional 3D electronic products, which shows great potentials in consumer electronics, communication engineering, and automobile and aerospace industries.

No abstract

With increasing interest in the rapid development of customized ceramic electronics, hybrid additive manufacturing (HAM) technology has become a competent alternative to traditional solutions such as printed circuit boards and cofired ceramic technology. Herein, the novel HAM technology is proposed by combining a dispensing three-dimensional (3D) printing process and selectively laser-activated electroless plating for fabricating 3D fully functional ceramic electronic products. An appropriative 3D-printable and metalizable low-temperature cofired ceramic slurry is developed to build the green body of ceramic electronics. After the debinding and sintering process, the 3D ceramic structure can be selectively laser-activated and then electrolessly plated to achieve electronic functionality. The thickness of the plated copper layer approaches 10 μm after 4 h of plating, and the electrical conductivity is 5.5 × 107 S m–1, which is close to pure copper (5.8 × 107 S m–1). To reduce the surface roughness of the laser-activated ceramic surface and thereby enhance the conductivity of the copper layer, the laser parameters are optimized as a 1250 mm s–1 scan speed, a 0.4 W laser power, and a 20 kHz laser-spot frequency. A high-power 3D light-emitting diode circuit board with an internal cooling channel is successfully developed to prove the feasibility of this HAM technology for customizing fully functional 3D conformal ceramic electronics.

Ceramic electronics have the advantages of large ampacity, high thermal conductivity, and excellent dielectric properties which are widely used in power electronics, optoelectronics, automotive industry, and aerospace technology. This work proposes a multimaterial dispensing additive manufacturing technology for customizing the 3D low‐temperature‐cofired ceramic (LTCC) circuitry. Customized LTCC aqueous slurry is first developed and then 3D printed together with commercial silver paste to build the green body. Then, the green body is debinded and sintered with a three‐stage process at 200, 500, and 850 °C, respectively. The shrinkage rate in 3D is around 17% which is comparable with commercial LTCCs. The surface quality of the sintered ceramic is improved obviously compared with that of the green body due to the glazing effect of the glass phase. For the silver conductor, the resistivity and the temperature coefficient of resistance are 2.34 ± 0.04 µΩ cm and 3.56 × 10−3 °C−1, respectively. A serial of demonstrators including 2D, 3D light‐emitting diode ceramic circuit boards and a ceramic heater/thermometer is developed to prove the potential and feasibility of the proposed technology.