Grantee Research Project Results
Green Nanosolder Paste for Next Generation Electronics Assembly and Manufacturing
EPA Grant Number: SU835938Title: Green Nanosolder Paste for Next Generation Electronics Assembly and Manufacturing
Investigators: Gu, Zhiyong
Current Investigators: Gu, Zhiyong , Gao, Fan , Wernicki, Evan , Shu, Yang , Fratto, Edward , Wang, Jirui , Kepner, Robert , Essigmann, Mikayla
Institution: University of Massachusetts - Lowell
EPA Project Officer: Page, Angela
Phase: II
Project Period: October 1, 2015 through September 30, 2017 (Extended to August 31, 2018)
Project Amount: $75,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet - Phase 2 (2015) Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Awards , P3 Challenge Area - Chemical Safety , Sustainable and Healthy Communities
Objective:
The objective of this project is to develop a new type of environmentally friendly solder paste, green lead‐free and halogen‐free nanosolder pastes. These new nanosolder pastes have the potential to replace the conventional solder paste with micron sized solder balls, which contains toxic and hazardous materials, including lead or halogen or both in a typical solder paste formulation in current electronics industry. As electronics and devices are getting smaller, lighter and more powerful, new assembling materials and methods are required to accommodate all electronic parts in a much smaller single device. The nanosolder pastes, composed of solder nanoparticles, can be an enabling material for next generation electronics assembly and manufacturing.
Approach:
An aqueous surfactant based chemical reduction method will be used to synthesize solder nanoparticles. The main focus of this project will be Sn/Ag/Cu (SAC) nanoparticles and their paste preparation. Nanosolders with high melting temperatures such as Au/Sn or low melting temperatures such as Sn/Bi or Sn/In will also be explored. Nanoparticles will be combined with fluxes based on halogen‐free chemistries, contrary to the commonly used halogen‐based flux materials, to prepare into a paste form. Selection of fluxes and related solvents, ratio of metal to solvents, and rheological properties of the solder pastes will be determined. Traditional stencil printing or modified techniques will be explored for the prepared paste formulations with optimization towards smaller solder paste printing sizes (≤ 200μm). Mechanical strength measurements and reliability tests (thermal cycling) will be conducted to determine the solder joint quality. Nanoparticle exposure measurements will be performed to monitor the presence and size characteristics of nanoparticles during the preparation and paste formulation stages, in collaboration with the Massachusetts Toxics Use Reduction Institute (TURI).
Expected Results:
Solder nanoparticles with controlled sizes will be synthesized in this project, which will result in nanoparticles with varied melting temperatures. Lead‐free and halogen‐free nanosolder pastes will be prepared at preferred conditions by flux selection and optimal metal to solvent ratio. The final paste formulations are expected to be compatible with screen printing processes with feature sizes around or below 200μm. The microstructure and mechanical property of the solder joints will be studied with an expectation of increased mechanical and reliability properties. Ultimately, these nanosolder pastes have the potential to enable stronger, more reliable, and smaller joints, which will significantly impact future electronic manufacturing processes.
Publications and Presentations:
Publications have been submitted on this project: View all 16 publications for this projectJournal Articles:
Journal Articles have been submitted on this project: View all 1 journal articles for this projectSupplemental Keywords:
Solder paste, Lead‐free, Halogen‐free, Nanoparticles, Low melting point, Electronics assembly and packaging, Green electronics;Relevant Websites:
P3 Phase 1: Green Nanosolder Paste for Next-Generation Electronics Assembly and ManufacturingProgress and Final Reports:
P3 Phase I:
Green Nanosolder Paste for Next-Generation Electronics Assembly and Manufacturing | Final ReportThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.