US 11,911,814 B2
Method of forming an elongate electrical connection feature traversing a microscopic step
Łukasz Witczak, Łódź (PL); Piotr Kowalczewski, Łódź (PL); Aneta Wiatrowska, Wroclaw (PL); Karolina Fia̧czyk, Wroclaw (PL); Łukasz Kosior, Wroclaw (PL); and Filip Granek, Mrozów (PL)
Assigned to XTPL S.A., Wroclaw (PL)
Filed by XTPL S.A., Wroclaw (PL)
Filed on Aug. 2, 2021, as Appl. No. 17/391,633.
Claims priority of provisional application 63/060,762, filed on Aug. 4, 2020.
Prior Publication US 2022/0040743 A1, Feb. 10, 2022
Int. Cl. B21C 23/00 (2006.01); H01L 33/62 (2010.01); B22F 3/20 (2006.01)
CPC B21C 23/005 (2013.01) [B22F 3/20 (2013.01); H01L 33/62 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method of forming an elongate electrical connection feature traversing at least one microscopic step on or in a substrate, comprising the steps of:
(A) continuously extruding a metallic nanoparticle composition from a capillary tube while displacing the capillary tube relative to the substrate from a first position to a second position, the first position and the second position being at a step bottom portion, the displacing being predominantly lateral, the extruded metallic nanoparticle composition overlying and contacting the step bottom portion;
(B) extruding the metallic nanoparticle composition from the capillary tube while displacing the capillary tube relative to the substrate from the second position to a third position, the third position being at a height not lower than a step top portion, the extruded metallic nanoparticle composition extending between the step bottom portion and the step top portion and contacting a sidewall of the at least one microscopic step; and
(C) continuously extruding the metallic nanoparticle composition from the capillary tube while displacing the capillary tube relative to the substrate from the third position to a fourth position, the fourth position being at a step top portion, the displacing being predominantly lateral, the extruded metallic nanoparticle composition overlying and contacting the step top portion;
wherein the step (B) of extruding the metallic nanoparticle composition comprises the sub-steps of:
(BI) continuously extruding the metallic nanoparticle composition from the capillary tube while raising the capillary tube by a height increment during a displacement period;
(B2) continuously extruding the metallic nanoparticle composition from the capillary tube while the capillary tube is stationary during a stationary period; and
(B3) repeatedly executing sub-steps (B1) and (B2) until the capillary tube reaches the third position.