Flip chip silicon die and package substrates have different coefficients of thermal expansion (CTE). Flip chip die are increasingly thinner, which can lead to warpage during thermal processing. Upward (smiling) and downward (crying) flip chip warpage can reduce package reliability.
LOCTITE ECCOBOND UF 8840 is compatible with various flux systems, has minimum resin bleed out, is compatible with needle dispensing and non-contact dispensing and has a wide dispense process window. LOCTITE ECCOBOND UF 8840, has been formulated to flow consistently with no voids on flip chip die up to 15mm2. It can be used with a variety of die passivations.
Henkel tested the underfill against competitive materials, reporting less warpage and lower stress. The underfill delivered <80µm warpage on a 20mm2 flip chip die with 730µm thickness. It also was evaluated by packaging houses, where LOCTITE ECCOBOND UF 8840 delivered high device reliability and minimal warpage-induced stress on 155µm-thick flip chip die.
Henkel operates worldwide with leading brands and technologies in three business areas: Laundry & Home Care, Cosmetics/Toiletries and Adhesive Technologies. Founded in 1876, Henkel holds globally leading market positions both in the consumer and industrial businesses with well-known brands such as Persil, Schwarzkopf and Loctite. Henkel employs about 47,000 people and reported sales of $21.7 billion and adjusted operating profit of $2.8 billion in fiscal 2011. Henkel’s preferred shares are listed in the German stock index DAX. Learn more at www.henkel.com/electronics.