| abstract |
Electrode pads ( 5 ) and a solder resist ( 7 ) are disposed on the upper surface of a wiring board ( 1 ), and apertures ( 7 a ) are formed in the solder resist ( 7 ) so as to expose the electrode pads ( 5 ). Electrodes ( 4 ) are disposed on the lower surface of a semiconductor element ( 2 ). Electrodes ( 4 ) are connected to the electrode pads ( 5 ) by way of bumps ( 3 ). An underfill resin ( 6 ) is disposed in the area that excludes the solder resist ( 7 ) and the bumps ( 3 ) in the space between the wiring board ( 1 ) and the semiconductor element ( 2 ). Between the wiring board ( 1 ) and the semiconductor element ( 2 ), the thickness (B) of the solder resist ( 7 ) is equal to or greater than the thickness (A) of the underfill resin ( 6 ) on the solder resist ( 7 ). The volume (Vb) of the bumps ( 3 ) is less than the volume (Vs) of the apertures ( 7 a ). |