Because of low copper diffusivity, low temperature curing, low moisture adsorption and proven high reliability, researchers at Dow Electronic Materials chose to modify its BCB material platform and developed a self-priming, low stress, aqueous developable version known as AD-BCB.
CYCLOTENE™ 6505 RDL Resin is Dow Electronic Materials’ first generation positive-tone AD-BCB photodielectric material and is currently in high volume manufacturing (HVM) for multi-layer metal redistribution (RDL) application. This aqueous developable photodielectric material has excellent mechanical, thermal, electrical, chemical resistance and lithographic performance. However, it requires a separate spin-on priming step. In addition, this photodielectric material has a stress value of 29MPa with an elongation of 11%. To meet the warpage targets for thinned 300mm wafers, lower residual stress is required.
Dow’s Advanced Packaging Technologies group has developed a prototype dielectric material, 14-P020, which reduces residual stress to less than 25MPa and at the same time more than double the elongation of this dielectric material. You can learn more about this material by
viewing this presentation presented at the 2015 IMAPS International Device Packaging Conference.