Thermal Adhesive Tempers Stacked Die Packages

Focussing on stacked die packages, QMI 9503 thermally-conductive dielectric adhesive can secure ICs and components to substrates found in PBGAs and CSPs and arrays that use flexible tape and organic laminates. The adhesive is a combination of thermally-conductive filler and collapsible spacers. Non-abrasive on polyimide passivation, the filler remains hydrophobic and stable at high temperatures while producing void-free bond lines. It also exhibits high resistance to delamination and popcorning after multiple exposures to reflow temperatures. The collapsible spacers maintain bond-line thickness to within 1.2 mm. Thermal conductivity of the QMI 9503 is 0.8 W/mK and it can be cured in-line via skip-cure processing in 10s after the bond line reaches 150°C. Alternatively, it can be cured in a conventional oven for 15 min. at 150°C. The adhesive meets JEDEC Level 3 standards and is qualified for use in lead-free, 260°C reflow soldering. HENKEL LOCTITE CORP., Rocky Hill, CT. (800) 562-8483.