Adhesives, electrically conductive moisture absorption

Moisture absorption can influence the reliability of conductive adhesive interconnection joints. Moisture in polymer composites is known to have an adverse effect on both the mechanical and electrical properties of epoxy laminates [54,55]. Studies relating to the reliability and moisture sensitivity of electronic packages indicate similar degrading effects. It was determined that moisture absorption can cause an increase in contact resistance, especially if the metallization on the bond pads and components is not a noble metal [56]. Effects of moisture absorption on conductive adhesive joints are summarized in Table 2. In order to achieve high reliability, conductive adhesives with low moisture absorption are required. High adhesion strength to pad... [Pg.744]

A fourth generation of electrically conductive adhesives based on cyanate esters and modified cyclo-olefin thermoset (MCOT) resins was introduced in the 1990s. These resins were specially formulated for low moisture absorption, high thermal stability, and low stress to be compatible with solder-reflow conditions. They were developed to prevent or reduce the so-called popcorn effect, a failure mode attributed... [Pg.27]