Authors: Amit Patel, Rahul Raut, Ranjit Pandher, Ph.D., Ramazan Soydan, Westin Bent and Ravi Bhatkal, Ph.D. and Brent Sweitzer, James Toonen, Bob Hanson Company: Alpha, an Alent plc Company and Multek Date Published: 3/28/2017
Abstract: This paper presents a structured study covering the assembly of mid power LED packages on thermally conductive polyethylene terephthalate (PET/Polyester) and polyimide flexible substrates. The study evaluates the feasibility of using PET as a low cost, low temperature alternative with SnBi Alloy to traditional polyimide with SAC based alloy assemblies. Initially, an assembly method was developed for both polyimide and PET based substrates. In order to validate the use of PET as an alternative to polyimide substrates , electrical testing, voiding, and thermal cycling tests were conducted. The results of processability and long term reliability of using low temperature solders (SnBi based SBX02 alloy) on PET versus traditional SAC 305 on polyimide are presented in this paper.
SSL, LED, Low Temperature Assembly, Flexible Circuits, Polyimide and PET Substrates, Sn-Bi, SBX02, Solder Paste