Circuit board structure with concave conductive cylinders and method for fabricating the same

Abstract

A method for fabricating a circuit board structure with concave conductive cylinders is provided. Firstly, a conductive layer is provided; a plurality of conductive cylinders are formed on a surface of the conductive layer; a dielectric layer is formed on the surface of the conductive layer with the conductive cylinders; the tips of the conductive cylinders are exposed on a surface of the dielectric layer far away from the conductive layer; removing the exposed tips of the conductive cylinders such that the height of the conductive cylinders is lower than the height of the dielectric layer, and the conductive cylinders sunk into the dielectric layer.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application claims the priority benefit of Taiwan application serial no. 96127050, filed on Jul. 25, 2007. All disclosure of the Taiwan application is incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a circuit board structure and the fabricating method thereof, more specifically, the present invention relates to a circuit board structure with concave conductive cylinders and the fabricating method thereof.[0004]2. Description of Related Art[0005]Generally, conventional circuit boards used to carry and electrically connect a plurality of electronic elements are mainly formed with a plurality of interlayered patterned conductive layers and dielectric layers. The patterned conductive layers are defined and formed through patterning copper foil directly, or through copper electroplating upon copper foil to increase the thickness of conductive layer and then g...

AI Technical Summary

Benefits of technology

[0008]The present invention provides a circuit board structure with concave conductive cylinders and the fabricating method thereof, for fabricating circuit board structure with concave conductive cylinders, so that the bonding quality between solder material and conductive cylinder is better.

[0009]The present invention provides a fabricating method of circuit board structure with concaved conductive cylinders. The method includes: providing a conductive layer first; forming a plurality of conductive cylinders on a surface of the conductive layer; forming a dielectric layer on the surface of the conductive layer on which the conductive cylinders are formed; exposing the tips of these conductive cylinders out of a surface of the dielectric layer relatively far away from the conductive layer; removing the tips of the conductive cylinders, so that the height of the conductive cylinders is lower than the height of the dielectric layer and the conductive cylinders sunk into the dielectric layer.

[0023]Since the present invention forms the dielectric layer on the outside of the conductive layer, to substitute the function of solder mask layer, therefore the solder mask opening drift problem occurred in the prior arts because the solder mask layer has to align with the pads, or the problem that the solder mask openings are too small when image transfers can be avoided. In addition, since the conductive cylinders are sunk into the dielectric layer, so that the solder material can be filled in the dielectric layer and to effectively bond to the conductive cylinders, therefore the bonding reliability of the solder material and the conductive cylinders can be improved, and disposing pads is no more required.

Problems solved by technology

In addition, when an image transfers, light leaking, under exposure, less developing power or incomplete development may also lead to too small openings 132.

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