Semiconductor package with heat dissipating structure

Abstract

A semiconductor package with a heat dissipating structure is provided. The heat dissipating structure includes a flat portion, and a plurality of support portions formed at edge corners of the flat portion for supporting the flat portion above a chip mounted on a substrate. The support portions are mounted at predetermined area on the substrate without interfering with arrangement of the chip and bonding wires that electrically connect the chip to the substrate. The support portions are arranged to form a space embraced by adjacent supports and the flat portion, so as to allow the bonding wires to pass through the space to reach area on the substrate outside coverage of the heat dissipating structure; besides, passive components or other electronic components can be mounted on the substrate at area within or outside the coverage of the heat dissipating structure, thereby improving flexibility in component arrangement in the semiconductor package.

Description

FIELD OF TIE INVENTIONThe present invention relates to semiconductor packages, and more particularly, to a semiconductor package with a heat dissipating structure.BACKGROUND OF TIE INVENTIONBall grid array (BGA) semiconductor packages are mainstream package products in the light of providing a sufficient amount of I / O (input / output) connections for use with semiconductor chips that incorporate high density of electronic elements and electronic circuits. As such a highly-integrated chip operates to consequently produce relatively more heat, it is thereby important to promptly remove the heat from the chip; otherwise, heat accumulation in the chip would undesirably damage electrical performances and reliability of package products. Moreover, for protecting internal components of the semiconductor package against external contamination, it usually forms an encapsulant that encapsulates the chip and other conductive elements such as bonding wires. The encapsulant is made of a resin mate...

AI Technical Summary

Benefits of technology

An objective of the present invention is to provide a semiconductor package with a heat dissipating structure, wherein the heat dissipating structure is arranged in a manner not to interfere with layout of a chip, bonding wires or passive components mounted on the substrate, thereby improving flexibility in component arrangement in the semiconductor package.

Another objective of the invention is to provide a semiconductor package with a heat dissipating structure, so as to reduce surface area of a substrate occupied by the heat dissipating structure, and thus to increase layout area on the substrate for accommodating bonding wires and passive components.

A further objective of the invention is to provide a semiconductor package with a heat dissipating structure, so as to improve heat dissipating efficiency of the semiconductor package.

In the above package structure, the flat portion of the heat dissipating structure is elevated above the chip by the support portions and forms a predetermined height difference with respect to the substrate, wherein the height difference is at least corresponding to height of wire loops of the bonding wires. Therefore, part of bond fingers where the bonding wires are bonded can be formed on the substrate at area outside the coverage of the heat dissipating structure, allowing the corresponding bonding wires to pass through the space embraced by adjacent support portions and the flat portion and to reach the outside-coverage bond fingers. Besides, passive components or other electronic components may also be desirably mounted on the substrate at area within or outside the coverage of the heat dissipating structure, thereby improving flexibility in component arrangement in the semiconductor package. Moreover, by the above structural arrangement, more flexibly-sized heat dissipating structures or chips can be adopted in the semiconductor package as long as the support portions of the heat dissipating structure are mounted on the substrate at area without affecting the arrangement of the chip and the bonding wires. Furthermore, the heat dissipating structure with multiple individual support portions, instead of a conventional single encircled support portion (as shown in FIG. 6), can desirably reduce surface area of the substrate occupied by the heat dissipating structure, thereby increasing layout area on the substrate for accommodating the bonding wires, passive components or other electronic components.

In another embodiment, the flat portion of the heat dissipating structure, having a top surface exposed to outside of the encapsulant and a bottom surface connected to the support portions, is formed with at least a peripherally-situated recess on the top surface and at least a protrusion on the bottom surface. During a molding process for forming the encapsulant by an encapsulating resin, when flowing to the peripherally-situated recess, the encapsulating resin would quickly absorb heat from an encapsulating mold and slow down its flowing speed without flashing over the exposed top surface of the flat portion, thereby helping assure reliability of fabricated package products. Moreover, the protrusion formed on the flat portion extends toward the chip mounted on the substrate and shortens the distance between the flat portion and the chip, by which heat generated from the chip can be efficiently transmitted to the heat dissipating structure for dissipation, such that heat dissipating efficiency of the semiconductor package is desirably improved.

Problems solved by technology

As such a highly-integrated chip operates to consequently produce relatively more heat, it is thereby important to promptly remove the heat from the chip; otherwise, heat accumulation in the chip would undesirably damage electrical performances and reliability of package products.

The encapsulant is made of a resin material with poor thermal conductivity (coefficient of thermal conductivity around 0.8w / m°K); therefore, the chip-generated heat would not be efficiently dissipated to the atmosphere through the encapsulant; this would thereby adversely affect performances and lifetime of the chip by virtue of heat accumulation.

However, this heat dissipating structure is embedded in the encapsulant, such that the chip-generated heat still needs to pass through the encapsulant for dissipation.

Therefore, this structural arrangement cannot achieve satisfactory improvement in heat dissipating efficiency for the semiconductor package.

However, the above semiconductor package 3 has significant drawbacks.

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