Nec Corporation

Akira Ohuchi

Tomoo Murakami

Electrode pads () and a solder resist () are disposed on the upper surface of a wiring board (), and apertures () are formed in the solder resist () so as to expose the electrode pads (). Electrodes () are disposed on the lower surface of a semiconductor element (). Electrodes () are connected to the electrode pads () by way of bumps (). An underfill resin () is disposed in the area that excludes the solder resist () and the bumps () in the space between the wiring board () and the semiconductor element (). Between the wiring board () and the semiconductor element (), the thickness (B) of the solder resist () is equal to or greater than the thickness (A) of the underfill resin () on the solder resist (). The volume (Vb) of the bumps () is less than the volume (Vs) of the apertures ().

Semiconductor device and manufacturing method thereof

A packaging structure and a packaging method reworkable even after the formal curing and good in connection reliability, characterized in that an electrode of a semiconductor device and an electrode of a substrate are electrically connected via bumps a first resin decreasing in mechanical strength and becoming reworkable under given conditions and a second resin capable of mitigating the stress due to a difference in thermal expansion coefficient between the semiconductor device and the substrate and superior in mechanical strength to the first resin under the given conditions are stacked and formed in the gap between the semiconductor device and the substrate and moreover the first resin is formed at a thickness of less than a half of said gap in total on the surface of at least either of the semiconductor device and the substrate

Growing community of inventors

Tokyo, Japan

Akira Ohuchi