Title :
Development of high reliability underfill material
Author_Institution :
Electr. Device Mater. Lab., Sumitomo bakelite Co. Ltd., Tochigi, Japan
Abstract :
As an encapsulant for flip chip packages, underfill materials play an important role for the purpose of protection from thermal stress and environmental stress. We have developed an excellent reliability underfill material based on the following concepts: (1) cured underfill material coefficient of thermal expansion (CTE) which is close to that of the solder ball; (2) excellent adhesion to plastic circuit board; (3) little change in material properties after moisture uptake. The material can be cured for 60 min, has JEDEC level 3 reliability and passes 1000 cycle temperature cycling tests. In order to shorten the cure schedule of this material, we have studied the following: (a) an additive agent with hydrophobic structure; (b) a catalyst. Based on these studies, we have developed a shorter cure (30 min.) type underfill
Keywords :
adhesion; assembling; catalysts; encapsulation; environmental degradation; flip-chip devices; heat treatment; integrated circuit packaging; integrated circuit reliability; integrated circuit testing; moisture; soldering; thermal expansion; thermal stresses; 30 min; JEDEC level 3 reliability; additive agent; adhesion; catalyst; cure schedule; cure time; cured underfill material coefficient of thermal expansion; encapsulant; environmental stress protection; flip chip packages; high reliability underfill material; hydrophobic structure; material curing; material properties; moisture; plastic circuit board; reliability; solder ball CTE; temperature cycling tests; thermal stress protection; underfill materials; Adhesives; Flip chip; Material properties; Materials reliability; Packaging; Plastics; Printed circuits; Protection; Thermal expansion; Thermal stresses;
Conference_Titel :
IEMT/IMC Symposium, 2nd 1998
Conference_Location :
Tokyo
Print_ISBN :
0-7803-5090-1
DOI :
10.1109/IEMTIM.1998.704517
