Wiring board and method for manufacturing the same and semiconductor device and method for manufacturing the same

A method for manufacturing a wiring board, comprising the steps of:

• using a film base on which a plurality of conductive wirings are aligned;
• forming a photoresist on a face of the film base on which the conductive wirings are provided, forming an aperture in a slot-shaped pattern traversing the aligned conductive wirings and including a region on both sides of the conductive wirings, so as to allow a part of the conductive wirings to be exposed in the slot-shaped pattern;
• and
• conducting metal plating with respect to the exposed part of the conductive wirings through the slot-shaped pattern of the photoresist to form protrusion electrodes,
• wherein the film base used comprises a first conductive wiring having a wiring width of W1 and a second conductive wiring having a wiring width of W2 larger than W1 as the conductive wirings provided thereon,
• the protrusion electrode formation step by the metal plating is conducted in such a manner that a relationship of heights of the protrusion electrodes formed by the metal plating with reference to widths of the conductive wirings changes through region A, region B and region C successively as the width of the conductive wirings increases, where in the region A the height of the protrusion electrodes increases with an increase in the width of the conductive wirings, in the region B the protrusion electrode higher than in the region A is formed and the height of the protrusion electrodes becomes a maximum, and in the region C the protrusion electrode lower than in the region B is formed and the height of the protrusion electrodes decreases, and
• the wiring width W1 of the first conductive wiring is set within the region A and the wiring width W2 of the second conductive wiring is set within the region C.

A semiconductor device, comprising:

• a wiring board comprising a film base;
• a plurality of conductive wirings aligned on the film base;
• and protrusion electrodes formed of a plated metal in the vicinity of end portions of the conductive wirings, respectively, wherein an outer surface at both side portions of the protrusion electrodes in cross section in a width direction of the conductive wirings defines a curve, and the protrusion electrodes in cross section in a longitudinal direction of the conductive wirings define a rectangular shape, the conductive wirings comprise a first conductive wiring having a wiring width of W1 and a second conductive wiring having a wiring width of W2 larger than W1, and the protrusion electrode on the first conductive wiring and the protrusion electrode on the second conductive wiring have a substantially same height;
• and
• a semiconductor element mounted on the wiring board,
• wherein electrode pads of the semiconductor element and the conductive wirings are connected via the protrusion electrodes.

A method for manufacturing a semiconductor device, comprising the steps of:

• using a wiring board comprising a film base;
• a plurality of conductive wirings aligned on the film base;
• and protrusion electrodes formed of a plated metal in the vicinity of end portions of the conductive wirings, respectively, wherein an outer surface at both side portions of the protrusion electrodes in cross section in a width direction of the conductive wirings defines a curve, and the protrusion electrodes in cross section in a longitudinal direction of the conductive wirings define a rectangular shape, the conductive wirings comprise a first conductive wiring having a wiring width of W1 and a second conductive wiring having a wiring width of W2 larger than W1, and the protrusion electrode on the first conductive wiring and the protrusion electrode on the second conductive wiring have a substantially same height;
• forming an encapsulation resin over a region where the protrusion electrodes are formed on the conductive wirings;
• then disposing a semiconductor element above the wiring board so that electrode pads of the semiconductor element are opposed to the protrusion electrodes;
• and
• connecting the electrode pads of the semiconductor element with the conductive wirings via bonding with the protrusion electrodes.