Hi‐rel Multilayer Plated‐through Hole Utilising the EE‐1™ Process

Abstract

This paper describes the use of the EE‐1 process for making high‐reliability multilayer boards. The EE‐1 process eliminates the need for flash electroless copper for plated‐through holes. With this process, copper is directly electrodeposited onto an activated through‐hole. In addition to eliminating electroless deposition, the EE‐1 process claims to simplify process control, provide excellent copper‐to‐copper adhesion, and total backlight PTH coverage. Production experience with the process is extensive as it has been used at Photocircuits, Atlanta, since January 1986 in the fabrication of double‐sided boards. Test data of joint reliability and physical properties of copper in PTHs of multilayer boards obtained through this unique approach are presented. A special test, which directly measures the bond strength between through‐hole deposited copper and inner foil of multilayers, is also discussed.

Enhancement of polylactic acid films properties by incorporation of starch nanocrystals

“…Nanocrystals can be obtained through acid 10 and enzymatic 11 hydrolysis processes or the combination of chemical and physical methods. 12 When the acid hydrolysis process is used in starch granules, the breakdown of glycosidic bonds occurs in the amorphous part of the molecules and subsequently in the crystalline part, promoting the release of highly crystalline residues on a nanometric scale producing the starch nanocrystals (SNCs). 13 As the size of a particle decreases to the nanoscale, important changes occur in the surface area making these molecules reactive due to the abundance of hydroxyl groups available for other bonds.…”

“…The crystalline regions that compose the starch structure can be isolated and originate a highly reactive nanomaterial, such as nanocrystals. Nanocrystals can be obtained through acid 10 and enzymatic 11 hydrolysis processes or the combination of chemical and physical methods 12 . When the acid hydrolysis process is used in starch granules, the breakdown of glycosidic bonds occurs in the amorphous part of the molecules and subsequently in the crystalline part, promoting the release of highly crystalline residues on a nanometric scale producing the starch nanocrystals (SNCs) 13 .…”