Wiring electrodes are formed on a first principal surface of a base substrate. An insulation film partially covers the first principal surface of the base substrate and the wiring electrodes. The insulation film has opening portions where the base substrate and the wiring electrodes are not coated with the insulation film. An electronic component having bump electrodes is mounted on the mounting board by connecting the bump electrodes with the wiring electrodes in the opening portions. A gap between the first principal surface of the base substrate and the electronic component is filled with sealing resin. The opening portions are substantially orthogonal to the longitudinal direction of the wiring electrodes. The ratio of the minimum width of a portion of the base substrate exposed at each of the opening portions to the thickness of the insulation film may advantageously be greater than or equal to 2.
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a Divisional of U.S. patent application Ser. No. 10/644,487, filed Aug. 20, 2003 in the name of Hiroyuki ISHIZAKI, entitled MOUNTING BOARD AND ELECTRONIC DEVICE USING THE SAME, incorporated by reference.
A package board for flip-chip packaging on whose one surface an element is mounted in a facedown manner is provided. The package board has: an interconnection provided on the one surface; a bump formation region in which a bump electrically connecting the interconnection with an electrode pad of the element is provided; and an insulating film covering a part of the one surface outside of the bump formation region. The insulating film includes a girdle-shaped insulating film that is provided around a region and along a side of the bump formation region opposite to an edge of the package board. The insulating film further has an opening section formed within the region.
