Self-Folding PCB Kirigami: Rapid Prototyping of 3D Electronics via Laser Cutting and Forming

Abstract

This paper demonstrates laser forming, localized heating with a laser to induce plastic deformation, can self-fold 2D printed circuit boards (PCBs) into 3D structures with electronic function. There are many methods for self-folding but few are compatible with electronic materials. We use a low-cost commercial laser writer to both cut and fold a commercial flexible PCB. Laser settings are tuned to select between cutting and folding with higher power resulting in cutting and lower power resulting in localized heating for folding into 3D shapes. Since the thin copper traces used in commercial PCBs are highly reflective and difficult to directly fold, two approaches are explored for enabling folding: plating with a nickel/gold coating or using a single, high-power laser exposure to oxidize the surface and improve laser absorption. We characterized the physical effect of the exposure on the sample as well as the fold angle as a function of laser passes and demonstrate the ability to lift weights comparable with circuit packages and passive components. This technique can form complex, multifold structures with integrated electronics; as a demonstrator, we fold a commercial board with a common timing circuit. Laser forming to add a third dimension to printed circuit boards is an important technology to enable the rapid prototyping of complex 3D electronics.

3D Shape‐Morphing Display Enabled by Electrothermally Responsive, Stiffness‐Tunable Liquid Metal Platform with Stretchable Electroluminescent Device

“…Recent research in materials and micro/nano fabrication has tried to overcome this fundamental limitation by developing strategies for reconfiguring 2D planar electronics into 3D shapes. For example, researchers investigated various approaches for the 2D‐to‐3D reconfiguration based on thermoforming, [ 10–12 ] kirigami, [ 13–15 ] origami, [ 16–20 ] buckling, [ 21,22 ] 4D printing, [ 23,24 ] and stimuli‐responsive materials. [ 25–28 ] Despite these transformation methods, 3D displays that adopt the existing electronic form factors—that is, either rigid, bendable, or stretchable forms—are challenging to provide robust yet reconfigurable 3D interfaces with high structural sophistication.…”

“…Recent research in materials and micro/nano fabrication has tried to overcome this fundamental limitation by developing strategies for reconfiguring 2D planar electronics into 3D shapes. For example, researchers investigated various approaches for the 2D-to-3D reconfiguration based on thermoforming, [10][11][12] kirigami, [13][14][15] origami, [16][17][18][19][20] buckling, [21,22] 4D printing, [23,24] and stimuli-responsive materials. [25][26][27][28] Despite these transformation methods, 3D displays that adopt the…”

Three‐Dimensional Transformation of Membrane‐Type Electronics Using Transient Microfluidic Channels for the Sequential Selective Plasticization of Supportive Plastic Substrates

“…[ 28,37,41,42 ] On the other hand, plastics with relatively higher Young's moduli (e.g., polyethylene terephthalate (PET): 3.1 GPa, [ 43 ] polycarbonate (PC): 2.4 GPa, [ 43 ] acrylonitrile–butadiene–styrene (ABS) copolymer: 2.8 GPa, [ 43 ] polyimide (PI): 3.0 GPa, [ 44 ] polyethylene naphthalate (PEN): 3.3–9.6 GPa [ 45 ] and Parylene‐C: 1.3–3.5 GPa [ 46 ] ) allows a comparably smaller degree of strain. To overcome this intrinsic limitation, kirigami [ 47–49 ] /origami [ 50–54 ] ‐inspired transformation into 3D pop‐up, [ 47–49 ] wavy, [ 51 ] cube, [ 50,53,54 ] and even star‐shaped [ 52 ] structures is possible by manually controlling bending/folding, [ 47,48,50–52 ] hydraulic pressure, [ 49 ] laser exposure, [ 53 ] and a simple stretching/releasing process. [ 54 ] As an alternative option, plasticization of plastic substrates allows a high degree of electronics‐level shape transformation due to the dramatic reduction of Young's moduli by approximately several thousand pascals and the viscoplastic flow of the polymer chains.…”

“…[28,37,41,42] On the other hand, plastics with relatively higher Young's moduli (e.g., polyethylene tere phthalate (PET): 3.1 GPa, [43] polycarbonate (PC): 2.4 GPa, [43] acrylonitrile-butadiene-styrene (ABS) copolymer: 2.8 GPa, [43] polyimide (PI): 3.0 GPa, [44] polyethylene naphthalate (PEN): 3.3-9.6 GPa [45] and ParyleneC: 1.3-3.5 GPa [46] ) allows a compa rably smaller degree of strain. To overcome this intrinsic limita tion, kirigami [47][48][49] /origami [50][51][52][53][54] inspired transformation into 3D popup, [47][48][49] wavy, [51] cube, [50,53,54] and even starshaped [52] structures is possible by manually controlling bending/ folding, [47,48,[50][51][52] hydraulic pressure, [49] laser exposure, [53] and This study demonstrates a technique for the development of 3D electronics based on planar membrane-type devices and a supportive plastic (e.g., acrylonitrile butadiene styrene [ABS] used in this study) substrate containing internal microfluidic channels (µ-FCs) that allow selective plasticization and transformation after the insertion of a liquid plasticizer (e.g., N,N-dimethylformamide). The internal µ-FC has a strong advantage of transiency and does not require an additional removal process because the channels are self-closed by the swelling and dissolution of the plasticized regions.…”

Neural networks for predicting kerf characteristics of CO2 laser-machined FFF PLA/WF plates

“…[11]. Kerf profile (Kerf), cut average surface roughness (Ra), heat-affected zone (HAZ) and material removal rate (MRR) is considered crucial attributes that are investigated the most [16,17].…”