WIRING BOARD AND METHOD FOR MANUFACTURING THE SAME AND SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME

Abstract

A wiring board includes 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. 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 include 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. The wiring board is capable of supporting conductive wirings with a practically enough strength to withstand a stress applied during the connection between the protrusion electrodes of the film base and electrode pads of a semiconductor element, providing sufficient connection stability and coping with a narrow pitch of the semiconductor element.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a partial plan view of a tape carrier substrate according to one embodiment of the present invention, FIG. 1B is a cross-sectional view taken along the line A-A of FIG. 1A and FIG. 1C is a cross-sectional view taken along the line B-B of FIG. 1A.

FIG. 2 is a partial perspective view of the tape carrier substrate.

FIG. 3 shows the first half process of a manufacturing process of the tape carrier substrate.

FIG. 4 shows the last half process of the manufacturing process of the tape carrier substrate.

FIG. 5A schematically shows the relationship between the width of conductive wirings and the height of protrusion electrodes formed by the above manufacturing method, and FIG. 5B is a cross-sectional view showing the heights of the protrusion electrodes formed by metal plating conducted with respect to conductive wirings having different widths.

FIG. 6A is a plan view of a semiconductor device employing a tape carrier substrate as a disadvantageous example formed by the above manufacturing method, and FIG. 6B is a cross-sectional view taken along the line D-D of FIG. 6A.

FIG. 7A is a plan view of a semiconductor device employing a tape carrier substrate as an advantageous example formed by the above manufacturing method, and FIG. 7B is a cross-sectional view taken along the line E-E of FIG. 7A.

FIG. 8 shows a result of the experiment for verifying the relationship between the width of the conductive wirings and the height of the protrusion electrodes on the above-stated tape carrier substrate.

FIGS. 9A to 9B are cross-sectional views showing a process for mounting a semiconductor element on the tape carrier substrate to manufacture a semiconductor device.

FIG. 10 is a cross-sectional view showing another process for mounting a semiconductor element on the tape carrier substrate to manufacture a semiconductor device.

FIG. 11 is a cross-sectional view showing an exemplary conventional semiconductor device.

FIG. 12A is a partial plan view of an exemplary conventional tape carrier substrate, and FIG. 12B is a cross-sectional view taken along with the line F-F of FIG. 12A.

FIG. 13A is a plan view for explaining a break occurring at a connection portion between a protrusion electrode of an exemplary conventional tape carrier substrate and an electrode pad of a semiconductor element, and FIG. 13B is a cross-sectional view taken along the line G-G of FIG. 13A.

FIG. 14 is a plan view showing the positions susceptible to influences of a stress when a semiconductor element is mounted to a conventional tape carrier substrate.

Claims

1. A wiring board, comprising: a film base;a plurality of conductive wirings aligned on the film base; andprotrusion 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, andthe protrusion electrode on the first conductive wiring and the protrusion electrode on the second conductive wiring have a substantially same height.

2. The wiring board according to claim 1, wherein the protrusion electrodes are formed by metal plating, andassuming that during a process of forming the protrusion electrodes by the metal plating, a maximum of heights of the protrusion electrodes that change in accordance with a change in widths of the conductive wirings is hB, a height of the protrusion electrode formed on the first conductive wiring is h1 and a height of the protrusion electrode formed on the second conductive wiring is h2, the wiring width W1 and the wiring width W2 are set so that a difference between the heights of the protrusion electrodes establishes the following relationships: |h1−h2|<(hB−h1) and |h1−h2|<(hB−h2).

3. The wiring board according to claim 1, wherein the second conductive wiring is disposed at at least one of an end position of a line of the conductive wirings and an isolated position.

4. The wiring board according to claim 1, wherein a curvature radius of an outer surface at both side portions of the protrusion electrodes in cross section in the width direction of the conductive wirings is larger in the protrusion electrode on the second conductive wiring than in the protrusion electrode on the first conductive wiring.

5. 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; andconducting 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, andthe 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.

6. The method for manufacturing a wiring board according to claim 5, wherein assuming that a height of the protrusion electrode formed on the first conductive wiring is h1, a height of the protrusion electrode formed on the second conductive wiring is h2 and a height of the protrusion electrode formed on a conductive wiring having a width within the region B is hB, the wiring widths W1 and W2 are set so that a difference between the heights of the protrusion electrodes establishes the following relationships: |h1−h2|<(hB−h1) and |h1−h2|<(hB−h2).

7. The method for manufacturing a wiring board according to claim 6, wherein the wiring widths W1 and W2 are set so that the heights of the protrusion electrodes h1 and h2 are equal.

8. The method for manufacturing a wiring board according to claim 5, wherein the conductive wiring width W1 in the region A is 13 to 17 μm, the conductive wiring width WB in the region B is 18 to 22 μm, and the conductive wiring width W2 in the region C is 23 to 27 μm.

9. 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; anda semiconductor element mounted on the wiring board,wherein electrode pads of the semiconductor element and the conductive wirings are connected via the protrusion electrodes.

10. 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; andconnecting the electrode pads of the semiconductor element with the conductive wirings via bonding with the protrusion electrodes.

11. The method for manufacturing a semiconductor device according to claim 10, wherein when the electrode pads of the semiconductor element are connected with the protrusion electrodes, while the electrodes pads and the protrusion electrodes are brought into contact with each other and a pressure is applied thereto, ultrasonic waves are applied to a portion of the contact.