Paper
12 March 2015 Laser forward transfer of solder paste for microelectronics fabrication
Author Affiliations +
Abstract
The progressive miniaturization of electronic devices requires an ever-increasing density of interconnects attached via solder joints. As a consequence, the overall size and spacing (or pitch) of these solder joint interconnects keeps shrinking. When the pitch between interconnects decreases below 200 μm, current technologies, such as stencil printing, find themselves reaching their resolution limit. Laser direct-write (LDW) techniques based on laser-induced forward transfer (LIFT) of functional materials offer unique advantages and capabilities for the printing of solder pastes. At NRL, we have demonstrated the successful transfer, patterning, and subsequent reflow of commercial Pb-free solder pastes using LIFT. Transfers were achieved both with the donor substrate in contact with the receiving substrate and across a 25 μm gap, such that the donor substrate does not make contact with the receiving substrate. We demonstrate the transfer of solder paste features down to 25 μm in diameter and as large as a few hundred microns, although neither represents the ultimate limit of the LIFT process in terms of spatial dimensions. Solder paste was transferred onto circular copper pads as small as 30 μm and subsequently reflowed, in order to demonstrate that the solder and flux were not adversely affected by the LIFT process.
© (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Scott A. Mathews, Nicholas A. Charipar, Ray C.Y. Auyeung, Heungsoo Kim, and Alberto Piqué "Laser forward transfer of solder paste for microelectronics fabrication", Proc. SPIE 9351, Laser-based Micro- and Nanoprocessing IX, 93510Y (12 March 2015); https://doi.org/10.1117/12.2080410
Lens.org Logo
CITATIONS
Cited by 8 scholarly publications.
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Laser welding

Copper

Photomicroscopy

Silver

Printing

Optical lithography

Pulsed laser operation

Back to Top