This application claims the priority benefit of Taiwan application serial no. 100130539, filed on Aug. 25, 2011. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.
1. Field of the Invention
The invention relates to a semiconductor device and a manufacturing method thereof. More particularly, the invention relates to a semiconductor package structure and a manufacturing method thereof.
2. Description of Related Art
A chip package is used to protect exposed chips, lower the contact density of chips, and provide chips with good heat dissipation. When the contact density of a chip continuously increases and the area of the chip becomes smaller and smaller, it is difficult for the contact points of the chip to be re-distributed on the surface of the chip as a surface matrix. Even if the surface of the chip can accommodate all the contact points, the distance between each contact point will be too small, affecting the electrical reliability in the subsequent soldering of the solder balls.
Thus, in conventional technology, a molding compound can first be used to package the chip to increase the area of the chip, wherein an active surface of the chip and the bottom surface of the molding compound is exposed. Then, a redistribution layer is formed on the active surface of the chip and the bottom surface of the molding compound, and solder balls are respectively formed on the contact points of the redistribution layer, to act as a medium for an electrical connection between the chip and an external contact point. That is to say, the active surface of the chip and the solder balls are located on the same plane. Since mold flash is generated during packaging, this causes the molding compound to extend to a part of the active surface of the chip, which pollutes the active surface of the chip. Thus, this method is unable to be applied to CMOS chips.
Furthermore, the aforementioned method is unable to use a vertical stacking method to package multiple semiconductor components (such as chips) to the same package structure. Conventional methods use a design of molding compounds packaging chips to increase the area of a chip. However, since the redistribution layer is located on the active surface of the chip and the bottom surface of the molding compound, a stacking formation can not be used to stack the chips. Therefore, how to effectively reduce the thickness and dimensions of a package structure for multiple stacked chips, while considering the electrical reliability of the package structure, is a topic to be urgently resolved.
The invention provides a semiconductor package structure and a manufacturing method thereof. The invention has the advantages of low cost, simplicity in manufacturing, and adaptability for mass production.
The invention further provides a method of manufacturing a semiconductor package structure. The method includes the following steps. A chip is provided, wherein the chip includes an active surface and a back surface opposite to each other. The chip is disposed on a carrier, wherein the active surface faces the carrier. A first molding compound is formed on the carrier to cover the chip. A metal layer is disposed on the first molding compound. The metal layer includes an upper surface and a lower surface opposite to each other, a plurality of cavities formed on the upper surface and a plurality of protrusions formed on the lower surface and the corresponding to the cavities, wherein the protrusions are embedded into the first molding compound. The metal layer is patterned so as to form a plurality of pads on a portion of the first molding compound, wherein each of the cavities are respectively located on a top surface of each of the pads, and each of the protrusions are respectively located on a bottom surface of each of the pads. The carrier and the first molding compound are separated from each other. A plurality of through holes is formed on the first molding compound so as to expose the protrusions. A redistribution layer is formed on the first molding compound and the active surface of the chip, wherein a portion of the redistribution layer extends from the first molding compound to the active surface of the chip and the through holes, so that the chip is electrically connected to the pads through the portion of the redistribution layer. A plurality of first solder balls are formed on the redistribution layer, wherein a portion of the first solder balls are correspondingly disposed to the pads.
In an embodiment of the invention, the method of forming the cavities and protrusions includes: providing a metal material layer; forming a first patterned photoresist layer on a first surface of the metal material layer; removing a portion of the metal material layer by using the first patterned photoresist layer as a mask to form cavities on the first surface of the metal material layer; forming a second patterned photoresist layer on a second surface of the metal material layer; and removing a portion of the metal material layer by using the second patterned photoresist layer as a mask, to form protrusions on the second surface of the metal material layer.
In an embodiment of the invention, the method of patterning the metal layer includes: forming a third patterned photoresist layer on the upper surface of the metal layer; and removing a portion of the metal layer by using the third photoresist layer as a mask until a portion of the first molding compound is exposed.
In an embodiment of the invention, the method of manufacturing the semiconductor package structure further includes: forming a second solder ball on the top surface of each pad.
In an embodiment of the invention, the method of manufacturing the semiconductor package structure further includes: forming a second molding compound on the first molding compound, wherein the second molding compound covers the pads and the first molding compound.
In an embodiment of the invention, the method of manufacturing the semiconductor package structure further includes: performing a singulation process after forming the first solder balls so as to form multiple independent package units.
In an embodiment of the invention, the method of manufacturing the semiconductor package structure further includes: disposing the metal layer on the first molding compound when the first molding compound is in a half-cured state, so that the protrusions are embedded into the first molding compound; and performing a baking step towards the first molding compound and the metal layer before patterning the metal layer so as to cure the first molding compound.
The invention provides a semiconductor package structure, including a chip, a first molding compound, a metal layer, a redistribution layer and a plurality of first solder balls. The chip has an active surface and a back surface opposite to each other. The first molding compound covers the chip and has a plurality of through holes, wherein a bottom surface of the first molding compound and the active surface of the chip are substantially coplanar. The metal layer is disposed on a portion of the first molding compound, and includes a plurality of cavities, a plurality of protrusions corresponding to the cavities, and a plurality of pads. Each of the cavities are respectively located on a top surface of each of the pads, and each of the protrusions are respectively located on a bottom surface of each of the pads. The through holes expose the protrusions. A redistribution layer is disposed on the first molding compound and the active surface of the chip, wherein a portion of the redistribution layer extends from the first molding compound to the active surface of the chip and the through holes, so that the chip is electrically connected to the pads through the portion of the redistribution layer. A plurality of first solder balls is disposed on the redistribution layer, wherein a portion of the first solder balls are correspondingly disposed to the pads.
In an embodiment of the invention, the semiconductor package structure further includes a plurality of second solder balls, disposed on the top surface of the pads.
In an embodiment of the invention, the semiconductor package structure further includes, a second molding compound disposed on the first molding compound, wherein the second molding compound covers the pads and the first molding compound.
Based on the above, in the invention, since the metal layer that was formed beforehand is disposed on the first molding compound, thus the semiconductor package structure of the invention has a better heat dissipation effect, and the entire semiconductor structure reliability is increased through the metal layer, to prevent the entire structure from warpage effects. Furthermore, since the method of manufacturing the metal layer has the advantages of simplicity and adaptability for mass production, thus the semiconductor package structure of the invention that adopts the metal layer also effectively reduces production cost.
In order to make the aforementioned and other features and advantages of the invention more comprehensible, embodiments accompanying figures are described in detail below.
The accompanying drawings constituting a part of this specification are incorporated herein to provide a further understanding of the invention. Here, the drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
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To sum up, in the invention, since the metal layer that was formed beforehand is disposed on the first molding compound, thus the semiconductor package structure of the invention has a better heat dissipation effect, and the entire semiconductor structure reliability is increased through the metal layer, to prevent the entire structure from warpage effects. Furthermore, since the method of manufacturing the metal layer has the advantages of simplicity and adaptability for mass production, thus the semiconductor package structure of the invention that adopts the metal layer also effectively reduces production cost.
Although the invention has been described with reference to the above embodiments, it will be apparent to one of the ordinary skill in the art that modifications to the described embodiment may be made without departing from the spirit of the invention. Accordingly, the scope of the invention will be defined by the attached claims not by the above detailed descriptions.
Number | Date | Country | Kind |
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100130539 | Aug 2011 | TW | national |