Semiconductor package with electromagnetic shielding capabilities

A semiconductor package with electromagnetic shielding capabilities is disclosed. The semiconductor package includes a substrate (101), a plurality of semiconductor dies (102), a plurality of shielding metal elements (103), a plurality of grounding metal elements (104) and a plurality of conductive metal elements (110). The semiconductor dies are disposed on an upper surface (105) of the substrate along a horizontal direction. The shielding metal elements are provided on the upper surface of the substrate, and are arranged between and around the semiconductor dies so that each semiconductor die is surrounded by the shielding metal elements and thus electromagnetic interference in the horizontal direction can be effectively shielded from each semiconductor die.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a semiconductor package, and particularly to a semiconductor package with electromagnetic shielding capabilities.

2. Description of Prior Art

Electromagnetic interference (EMI) is a naturally occurring electromagnetic phenomenon. The electromagnetic waves generated by electrical or electronic devices in operation may interfere with other surrounding electrical or electronic devices, which has adverse influences on the normal operation and the stable signal transmission of these devices. Further, excessive electromagnetic interference causes electromagnetic contamination, which adversely affects the human health and destructs the zoological balance. Electromagnetic compatibility between component devices of an electrical or electronic system is thus required to avoid function degradation or damage of the component devices caused by the electromagnetic interference therebetween, thereby ensuring the normal operation of the entire system. However, with the rapid development of the electrical and electronic industry, it has become more and more difficult to obtain such an electromagnetic compatibility status. To achieve the electromagnetic compatibility of the entire system, the amount of electromagnetic radiation emitted by each power consumption component of the system is required to be limited to a predetermined amount, and each power consumption component is also required to have a certain anti-interference capability. Only when both the amount of electromagnetic radiation emitted by each system component is limited and the anti-interference capability of each system component is improved, can the electromagnetic compatibility of the entire system be obtained.

Typically, in high-density semiconductor packaging, multiple dies can be arranged side-by-side or can be stacked vertically within the package to form a system-in-package (SiP). However, mutual electromagnetic interference occurs between the dies in the package, and external electromagnetic signals also interfere with the operation of these dies, which may result in damage of the dies and malfunction of the package incorporating these dies.

Hence, an improved semiconductor package having a shielding structure is desired to provide a more effective electromagnetic shielding capability. It is further desired that this shielding structure should not raise the overall height of the semiconductor package while effectively shielding electromagnetic interference between adjacent dies of the semiconductor package.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a semiconductor package having shielding metal balls disposed between and around adjacent dies thereof to effectively shield electromagnetic interference.

To achieve the above object, the present invention provides a semiconductor package with electromagnetic shielding capabilities. The semiconductor package includes a substrate, a plurality of semiconductor dies, a plurality of shielding metal elements, a plurality of grounding metal elements and a plurality of conductive metal elements. The semiconductor dies are disposed on an upper surface of the substrate along a horizontal direction in a spaced relationship with respect to one another. Each semiconductor die has a lower surface with a plurality of bumps formed thereon to electrically connect the semiconductor die with the substrate, whereby a connection area is defined between the lower surface of the semiconductor die and the upper surface of the substrate. The shielding metal elements, preferably in the form of metal balls, are provided on the upper surface of the substrate, and are arranged between and around the semiconductor dies so that each semiconductor die is surrounded by the shielding metal elements and thus electromagnetic interference in the horizontal direction can be effectively shielded from each semiconductor die. That is, a portion of the shielding metal elements is arranged between adjacent semiconductor dies so that the electromagnetic interference between the adjacent semiconductor dies can be shielded, and the remaining portion of the shielding metal elements is arranged around the outer peripheries of the semiconductor dies so that the external electromagnetic interference can also be shielded. Each shielding metal element has a height substantially equal to or smaller than a sum of height of the connection area and height of the semiconductor die.

Preferably, the present semiconductor package further includes a heat spreader that is disposed on the semiconductor dies to enhance the heat dissipation efficiency.

Further, a molding compound is preferably applied between the heat spreader and the upper surface of the substrate to increase the engagement strength between the heat spreader and the substrate.

Accordingly, the present semiconductor package provides a more effective EMI shielding capability by the employment of a plurality of shielding metal elements disposed between and around the semiconductor dies. Further, the overall vertical height of the present semiconductor package employing these shielding metal elements is not increased while providing such an effective EMI shielding effect. In addition, a heat spreader and a molding compound can be further incorporated into the present semiconductor package to respectively enhance the heat dissipation efficiency and the structural strength of the present semiconductor package.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring toFIG. 1, a semiconductor package with electromagnetic shielding capabilities in accordance with a first embodiment of the present invention includes a substrate101, a plurality of semiconductor dies102(two shown for simplicity), a plurality of shielding metal elements103, a plurality of grounding metal elements104and a plurality of conductive metal elements110. The shielding metal elements103, the grounding metal elements104and the conductive metal elements110are all preferably in the form of metal balls as shown.

The substrate101has an upper surface105and a lower surface106opposite to the upper surface105. A plurality of vias107is defined through the substrate101. The semiconductor dies102are disposed on an upper surface105of the substrate101along a horizontal direction, and are arranged substantially in a side-by-side relationship with respect to one another. Each semiconductor die102has a lower surface108with a plurality of bumps109formed thereon to electrically connect the semiconductor die102with corresponding circuits (not shown) on the substrate101. A connection area118is thus defined between the lower surface108of the semiconductor die102and the upper surface105of the substrate101. The plurality of bumps109is located within the connection area118to electrically connect each semiconductor die102with the substrate101. An underfill material may be injected into the connection area118as desired to bond the semiconductor die102and the substrate101together. The shielding metal elements103are provided on the upper surface105of the substrate101, and are arranged between and around the semiconductor dies102so that each semiconductor die102is surrounded by the shielding metal elements103and thus electromagnetic interference in the horizontal direction can be effectively shielded from each semiconductor die102. In detail, a portion of the shielding metal elements103is arranged between adjacent semiconductor dies102so that the electromagnetic interference between the adjacent semiconductor dies102can be shielded, and the remaining portion of the shielding metal elements103is arranged around the outer peripheries of the semiconductor dies102so that the external electromagnetic interference can also be shielded. Each shielding metal element103is electrically connected with an upper portion of a corresponding via107of the substrate101, and has a height substantially equal to or smaller than a sum of height of the connection area118and height of the semiconductor die102.

The grounding metal elements104are provided on the lower surface106of the substrate101and are each electrically connected with a lower portion of a corresponding via107of the substrate101. The grounding metal elements104are adapted to electrically connect with other grounding circuits (not shown), so that the shielding metal elements103can be grounded through the vias107. The conductive metal elements110, also provided on the lower surface106of the substrate101, are electrically connected with corresponding circuits (not shown) of the substrate101and serve as an input/output interface of the substrate101to input/output electrical signals from/to an external device, such as a motherboard. It should be noted that the shielding metal elements103and the grounding metal elements104of the present invention are respectively adopted for EMI shielding and grounding (or heat conducting) purposes, not for input/output of electrical signals. Therefore, the functions of the shielding metal elements103and the grounding metal elements104are completely different from that of the conductive metal elements110.

Reference is now directed toFIG. 2, which is a schematic view of a semiconductor package with electromagnetic shielding capabilities in accordance with a second embodiment of the present invention. This embodiment is different from the first embodiment in that a heat spreader111is further provided on the semiconductor dies102. The heat spreader111has a lower surface114in contact with the tops of the shielding metal elements103, so that the heat spreader111is grounded through the shielding metal elements103, the vias107and the grounding metal elements104. The adoption of the heat spreader111enhances the heat dissipation efficiency of the semiconductor package of the second embodiment. To achieve the heat dissipation purpose, the heat spreader111is preferably made of high thermal conductive metal materials such as copper, aluminum, silver and gold. A heat dissipation layer may be further selectively provided between the heat spreader111and each semiconductor die102for enhancing heat dissipation efficiency. The heat dissipation layer117is preferably in the form of thermal paste, for example, thermally conductive silver-filled paste.

FIG. 3is a schematic view of a semiconductor package with electromagnetic shielding capabilities in accordance with a third embodiment of the present invention. This embodiment is different from the second embodiment in that a molding compound112is further applied between the heat spreader111and the substrate101to reliably retain the heat spreader111on the substrate101. In addition, at least one engagement hole113is defined in each of the lower surface114of the heat spreader111and the upper surface105of the substrate101. The engagement holes113are filled with the molding compound112during injection molding of the molding compound112, whereby the bonding strength between the substrate101, the heat spreader111and the molding compound112is further increased. The engagement hole113may be in the form of a chamfered blind hole or a chamfered through hole.

In comparison with the conventional design, the present semiconductor package provides a more effective EMI shielding capability by the employment of a plurality of shielding metal elements103disposed between and around the semiconductor dies102. Further, the overall vertical height of the present semiconductor package employing these shielding metal elements103is not increased while providing such an effective EMI shielding effect. In addition, a heat spreader111and a molding compound112can be further incorporated into the present semiconductor package to respectively enhance the heat dissipation efficiency and the structural strength of the present semiconductor package.