Gap Adjustable Molten Metal DoD Inkjet System With Cone-Shaped Piston Head

Abstract

In this paper, we present the design, fabrication, and performance test of a gap adjustable molten metal drop-on-demand (DoD) inkjet system with a cone-shaped piston head, which can eject a droplet of lead-free molten solder at high temperature. The gap adjustable mechanism with the cone-shaped piston head is proposed for optimizing the gap distance between the chamber wall and piston head. The droplet diameter and velocity can be controlled in a wide range by moving the initial gap distance and minutely by controlling the chamber pressure. Stability and satellite can be partly adjusted by controlling the initial gap distance and the chamber pressure, respectively. The working temperature is improved by locating the piezoelectric actuator at the outside of the furnace and by inserting the insulation block between the print head and the actuator. From a practical point of view, the molten metal DoD inkjet system presents a simple structure for easily interchangeable nozzle parts, even though the nozzle is choked. The gap adjustable molten metal DoD inkjet system with cone-shaped piston head has great potential as a manufacturing tool for direct printing a viscous material at various temperatures. It is expected to be applicable in many industrial fields including semiconductor packaging, electrode bonding, printed electronics, information, and display industry.

Current Status of Liquid Metal Printing

“…Marusak developed a piezoelectric actuation scheme for jetting low-temperature Indalloy-58 for micron scale soldering [97]. Work continued through the beginning of the new century on advancing the use of piezoelectric driven actuation methods for molten metal jetting [98][99][100][101][102]. The previous piezoelectric techniques were in modes where the molten metal is directly ejected by expansion of the piezoelectric ceramic or crystal due to application of a voltage across the piezoelectric.…”

“…A drawback to ferroelectrics is the relatively low temperature phase transition (associated with the Curie temperature) between the ferroelectric and paraelectric phases, which for PZT (depending on the composition) is at most 380 • C. The maximum operating temperature for PZT and similar ferroelectrics; however, is typically around 1 2 the Curie temperature or transition temperature. Therefore, the maximum temperature for molten metal allowed in these setups would be at most 190 • C. Lee et al showed how to work around the temperature limits of a piezoelectric by insulating the piezoelectric and attaching a piston which is in contact with the molten metal as opposed to the diaphragm and piezoelectric [100,101]. Their piezoelectric DOD printer was also a push-mode printer with a piston insulating the piezoelectric from the molten metal.…”

“…This does not include statistical variations. Data to make this figure drawn from multiple sources[10,97,98,[100][101][102]106,114,127,[138][139][140][141]144,148,149,152,154,183,184].…”

Sustainable metal droplet formationviaopen-source, cost-effective, and modifiable droplet generator

“…In addition, having changeable parts and descriptive explanation of the piston tip geometry over the impact region were some of solid novelties of these studies. 7,8 Owing to the preliminary achievements, droplet generators are gaining popularity for various applications today. For the fields of both rapid prototyping and miniaturization in the metal industry, the droplet deposition is a promising methodology when the input parameters and the droplet properties are characterized in harmony.…”

EL Display Printed on Curved Surface

“…This is due to the superior price competitiveness of these technologies as compared to existing lithographic processes for manufacturing some parts used in the manufacture of display units, electronic papers, RF-ID information devices, and so on. The semiconductor manufacturing process requires a long manufacturing time and expensive equipment [1,2]. The photolithography and electro plating methods require acid washes and a substantially larger amount of material.…”