Effects of welding head on the carbon nanotube field emission in ultrasonic nanowelding

One‐Dimensional Nano‐Interconnection Formation

“…On the basis of the acoustic softening effect, ultrasonic nanowelding pinning is another promising approach to fix 1D nanostructures onto electrodes 50. For example, Chen et al have embedded single‐walled CNTs (SWNTs) into metal electrodes by this way and contacts exhibited favorable electrical characteristics and mechanical properties ( Figure ).…”

Ultrasonic Welding of Bulk Carbon Nanotube Conductors

“…In contrast, a textured Table illustrating different techniques investigated for contacting carbon nanotubes to metallic interconnects including traditional soldering, [7] conductive epoxies, [7] mechanical crimping, [17,18] and ultrasonic welding. [14,[19][20][21] knurl pattern (in contact with the Cu foil) used in combination with a smooth knurl pattern (in contact with the CNT test strip) provides a suitable welding surface to make a strong ultrasonic bond between the CNTs and the Cu. After repeated use, buildup of metallic residue on the textured knurl pattern can lead to the Cu foil sticking to the welding head ( Figure 2c).…”

“…[19] A second possible welding mechanism is the acoustic softening effect. [21] In this method, CNTs can embed themselves below the metal surface during ultrasonic welding, which results in high mechanical strength and lower contact resistances. [21] Protruding CNT ends above the metal surface can then provide electrical contact points and mechanical rigidity to other CNTs in the network, which are not directly welded to the metal contact.…”

“…[21] In this method, CNTs can embed themselves below the metal surface during ultrasonic welding, which results in high mechanical strength and lower contact resistances. [21] Protruding CNT ends above the metal surface can then provide electrical contact points and mechanical rigidity to other CNTs in the network, which are not directly welded to the metal contact. The ability for ultrasonic welding techniques to embed CNTs into the metal matrix has also been shown to lower the two-terminal electrical contact resistance between individual/small bundles of CNTs and the metal.…”

“…[14] Ultrasonic welding of bulk CNT conductors directly to metallic electrodes can be an efficient method to provide both the mechanical and electrical contacts. [14,[19][20][21] Because the ultrasonic welds do not require the addition of materials or epoxies, the contacts will not add additional mass to the system and likely have a low weld profile. However, it is necessary to determine welding conditions that will make the best electrical contact between CNTs and metal.…”