The importance of having adequate strength for the task at hand remains a constant concern for adhesives users. And plenty of adhesive developments still center around creating a stronger bond, particularly when it comes to troublesome metal and plastic substrates. Yet there's more to making a better adhesive than boosting strength. In fact, many of today's adhesive improvements address entirely different functional attributes. Some developments make adhesives easier to handle—both in storage and during their application. Others target productivity with faster cure times or easier cure methods. Still others seek to improve the thermal or electrical properties. Here's a look at three recent adhesives—two films and one liquid—that do more than bump up bond strengths.
Stubborn Substrates NO Problem
TechFilm 12202, a new structural B-staged film adhesive, takes on stubborn substrates and does so quickly. It offers bond strengths up to 4,500 psi on difficult-to-bond substrates—including metals like gold, invar, and nickel as well as various engineering plastics. With a cure time of 60 minutes at 150C, this 100 percent solid adhesive serves as an alternative to liquid adhesives and solders in intricate industrial and electronic bonding applications. TechFilm 12202 comes in both unfilled and filled versions, the latter incorporating thermally or electrically conductive fillers for thermal management and shielding. Available in sheet, preform, or roll formats down to 1 mil, this film adhesive targets sensors, print heads, and other electronic components with thickness constraints. For more information, go to http://rbi.ims.ca/4396-528.
Turn Up The Heat
Scapa North America's latest adhesive transfer film for electronics, automotive, and industrial assembly holds on when subjected to high temperatures. Called Unifilm U800B, this film retains its shear properties even at temperatures up to 200C. It's designed for use on flexible printed circuits, in liquid crystal displays, and with EMI shielding. Available in a thickness of 2.0 mils, this acrylic transfer film comes on a variety of printed and blank stay-flat release liners. U800B adheres to a variety of metals and plastics, including polyimide, polyester, and ABS. For more information, go to http://rbi.ims.ca/4396-529.
See The Cure
The next generation of silicone adhesive formulations from Henkel Corp. offers enhanced curing. These biocompatible Nuva-Sil silicones cure tack free to a depth of two inches in a matter of seconds when exposed to light. Like earlier silicone products, that light source can be UV. Yet, remarkably, the new silicones also cure under high-power visible light—whose safe, easy-to-use cure equipment costs less than UV systems. Nuva-Sil products include: Loctite 5031, a self-leveling liquid for potting, encapsulation and sealing applications; Loctite 5039, a semi leveling paste that forms gaskets or seals with minimal knit lines or seams; and Loctite 5033, a thixotropic paste for gasketing, sealing, and potting applications that require a full-bodied material. For more information, visit http://rbi.ims.ca/4396-530.