Circuit board structure and method for fabricating the same

Abstract

A circuit board structure and a method for fabricating the same are proposed. A plurality of conductive bumps and a first solder mask are formed on a carrier board, and the first solder mask is filled in the gaps between the conductive bumps and the conductive bumps are exposed. A first circuit layer and a first heat sink are formed on the first solder mask and the conductive bumps. A second heat sink is formed on the first heat sink, and a dielectric layer is formed on the first circuit layer and the first solder mask except the first and second heat sinks. A second circuit layer is formed on the dielectric layer and is electrically conductive to the first circuit layer. A third heat sink is formed on the second heat sink and a heat sink used for a chip mounting thereon is embedded in the dielectric layer. Therefore, the dimension of the circuit board is reduced and it is conformed to the dimension minimization progress of electronic devices.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] This invention relates to a circuit board structure and a method for fabricating the same, and more particularly, to a circuit board structure integrated with heat sinks and a method for fabricating the same. [0003] 2. Description of Related Art [0004] With the rapid development of electronic industry, modern electronic products have various functions and better performance. In order to meet the requirements of small dimension but high integration for a semiconductor chip, a circuit board, which is used for carrying a plurality of active and passive components, is changed from having only one layer to having multiple layers. [0005] However, such a small-dimensiond but highly integrated semiconductor chip generates considerate amount of heat, which easily overheats or even makes unrecoverable damage on the semiconductor chip [0006] Adhering a plurality of heat dissipating spreaders onto the circuit board is one of th...

AI Technical Summary

Benefits of technology

[0010] In views of the above-mentioned problems of the prior art, it is a primary objective of the present invention to provide a circuit board structure and a method fabrication the same, for providing a chip disposed on the circuit board structure a well heat dissipating path and reducing the dimension of a circuit board.

Problems solved by technology

However, such a small-dimensiond but highly integrated semiconductor chip generates considerate amount of heat, which easily overheats or even makes unrecoverable damage on the semiconductor chip

Moreover, the arc solder wires near the semiconductor chip 13 are crowded and easily short to each other.

However, the semiconductor chip 13 generally does not fit the mold and will not be fixed in the mold tightly and closely, so the epoxy resin is easily injected to a region outside of the mold and part of the encapsulant 15 are formed on the second surface 11b of the circuit board 11.

In result, the package structure 10 is uneven and looks untidy and some of the solder pads 17 may get contaminated, affecting the electrical conductive quality of the package structure 10 because the contaminated solder pads 17 and the solder balls 16 thereon can not be conductive tightly.

If the epoxy resin is injected excessively in terms of quantity and speed into the mold, the arc solder wires 16 will be drawn too close or even contact to each other, resulting in a short problem and degrading the package structure 10.

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