Patent Publication Number: US-9887145-B2

Title: Metal top stacking package structure and method for manufacturing the same

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a semiconductor chip package structure and a method for manufacturing the same, and more particularly to a metal top stacking package structure and a method for manufacturing the same. 
     2. Description of Related Art 
     A multichip package (MCP) structure is a package with a plurality of semiconductor chips integrated into a single package structure, so that density of electronic components is enhanced to shorten the electrical connecting channels between electronic components. This package not only reduces the overall size of the multichip but also enhances overall performance. 
     In conventional multichip package structure, a plurality of chips are stacked vertically, alternately, stepwise or otherwise, and then each of the chips is electrically connected to a substrate through wire bonding. In multi-semiconductor chips stacking package technology, a stacking package technology of multichip with same size is a conventional package technology. 
     In the known technology, please refer to  FIG. 1 , a thermally and electrically enhanced stacked semiconductor package  1  is provided. The semiconductor package  1  mainly comprises a chip carrier  11  used for electrically connecting the semiconductor package  1  to the external components; at least one second chip  12  is mounted on and electrically connected to the chip carrier  11  by a flip chip type; a heat sink  13  mounded over the first chip  12  and electrical connecting with the chip carrier  11 ; a conductive layer  14  and at least one second chip  15  electrical connecting with the working surface of the chip carrier  11  by electrically connecting wires and mounded on the non-working surface; a plurality of wires  16  and an encapsulate material  17  are formed on the chip carrier  11  and encapsulating the first chip  12 , the second chip  15 , the heat sink  13  and the other components, and partly the chip carrier  11 . 
     However, as shown in  FIG. 1 , the heat sink between the first chip and the second chip cannot achieve the ideal effect in heat dissipation and electromagnetic shielding; therefore, the heat energy during the working chips cannot effectively dissipate from the package, thereby reducing the chip stability and life time. Therefore, there is an urgent need for a metal top stacking package structure and a method for manufacturing the same, which provides heat dissipation and electromagnetic shielding by an optimum installation of the metal top; thereby enhancing electrical connection quality and life time of the chips. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a metal top stacking package structure, which the heat dissipation and the electromagnetic shielding can be provided by using an installation of the metal top. Therefore, it can be prevented working chips from malfunctioning and damaging. 
     To achieve the above object, the present invention provides a metal top stacking package structure, comprising a metal base including an upper surface and a lower surface, and a die receiver cavity formed in the upper surface; a first chip fixed on the die receiver cavity by a first adhesion layer; a substrate with an upper surface; a second chip fixed on the upper surface of the substrate by a second adhesion layer; and a plurality of connecting components formed on the upper surface of the substrate; wherein the upper surface of the metal base is connected with the substrate by the connecting components. 
     In the metal top stacking package structure of the present invention, the structure may further comprise a plurality of electrically connecting wires including first electrically connecting wires and second electrically connecting wires. An installation of these electrically connecting wires may be randomly varied based on stacking package conditions or the user&#39;s requirements; wherein a plurality of the first electrically connecting wires can be coupled the first chip with the metal base. Further, a plurality of the second electrically connecting wires may be coupled the second chip with the substrate. Besides, in the metal top stacking package structure of the present invention, an order of wire bonding may be randomly varied based on stacking package conditions or the user&#39;s requirements; wherein the wire bonding between the first chip and the metal base may be firstly performed, and then a wire bonding between the second chip and the substrate may be performed; alternatively, a wire bonding between the second chip and the substrate may be firstly performed, and then the wire bonding between the first chip and the metal base may be performed. 
     In the metal top stacking package structure of the present invention, the metal top stacking package structure may further comprise a heat sink formed on the lower surface of the metal base; wherein the heat sink may be a heat spreader, a heat pipe or a fan, but the present invention is not limited thereto. In an aspect of the present invention, the heat sink may be a heat spreader, and the material of the heat spreader is a copper material. The heat energy during the working chips may be dissipated to the other semiconductor chips or the metal base by the heat sink. 
     In the metal top stacking package structure of the present invention, the upper surface of the substrate may further comprise a metal layer; wherein the material of the metal layer may be randomly varied based on stacking package conditions or the user&#39;s requirements, and the material of the metal layer may be a magnesium alloy, an aluminum alloy, a copper alloy, a ferrous alloy, magnesium copper alloy or combinations thereof, but the present invention is not limited thereto. In an aspect of the present invention, the material of the metal layer may be magnesium alloy, and in another aspect of the present invention, the material of the metal layer may be copper alloy. 
     In the metal top stacking package structure of the present invention, the metal top stacking package structure may further comprise a first encapsulate material formed on the substrate and surrounding the metal base, the first chip, the second chip, the first adhesion layer, the second adhesion layer, the first electrically connecting wires, the second electrically connecting wires and the connecting components; wherein the lower surface of the metal base may be exposed. 
     In the metal top stacking package structure of the present invention, the metal top stacking package structure may further comprise a second encapsulate material formed in the receiver cavity of the metal base and surrounding the first chip, the first adhesion layer and the first electrically connecting wires. In the metal top stacking package structure of the present invention, the first encapsulate material and the second encapsulate material may be the same; the first encapsulate material and the second encapsulate material may be components selected from the group consisting of epoxy resin, ceramic powders, carbon black, but the present invention is not limited thereto. 
     Besides, another object of the present invention is to provide a method for manufacturing metal top stacking package structure, comprising: providing a metal base including a upper surface and a lower surface, and a die receiver cavity formed in the upper surface; forming a first adhesion layer on the die receiver cavity of the upper surface; fixing a first chip to the die receiver cavity of the upper surface by the first adhesion layer; providing a substrate with an upper surface; fixing a second chip to the upper surface of the substrate by the second adhesion layer; and a plurality of connecting components formed on the upper surface of the substrate; wherein the upper surface of the metal base may be connected with the substrate by the connecting components. 
     In the method for manufacturing metal top stacking package structure, the method may further comprise a plurality of first electrically connecting wires coupled the first chip with the metal base to input and output signals. Further, the method may further a plurality of second electrically connecting wires coupled the second chip with the substrate to input and output signals. Besides, in the method for manufacturing metal top stacking package structure, an order of wire bonding may be randomly varied based on stacking package conditions or the user&#39;s requirements; wherein the wire bonding between the first chip and the metal base can be firstly performed, and then a wire bonding between the second chip and the substrate can be performed; alternatively, a wire bonding between the second chip and the substrate can be firstly performed, and then the wire bonding between the first chip and the metal base can be performed. 
     In the method for manufacturing metal top stacking package structure, the method may further comprise a heat sink formed on the lower surface of the metal base; wherein the heat sink may be a heat spreader, a heat pipe or a fan, but the present invention is not limited thereto. In an aspect of the present invention, the heat sink may be a heat spreader. 
     In the method for manufacturing metal top stacking package structure, the method may further comprise a metal layer may be formed on the upper surface of the substrate; wherein the material of the metal layer may be randomly varied based on stacking package conditions or the user&#39;s requirements, and the material of the metal layer may be a magnesium alloy, an aluminum alloy, a copper alloy, a ferrous alloy, magnesium copper alloy or combinations thereof, but the present invention is not limited thereto. In an aspect of the present invention, the material of the metal layer may be magnesium alloy, and in another aspect of the present invention, the material of the metal layer may be copper alloy. 
     In the method for manufacturing metal top stacking package structure, the method may further comprise a first encapsulate material formed on the substrate and surrounding the metal base, the first chip, the second chip, the first adhesion layer, the second adhesion layer, the first electrically connecting wires, the second electrically connecting wires, and the connecting components; wherein the lower surface of the metal base may be exposed. 
     In the method for manufacturing metal top stacking package structure, the method may further comprise a second encapsulate material formed in the die receiver cavity of the metal base and surrounding the first chip, the first adhesion layer and the first electrically connecting wires. In the metal top stacking package structure of the present invention, the first encapsulate material and the second encapsulate material may be the same; and the first encapsulate material and the second encapsulate material may be components selected from the group consisting of epoxy resin, ceramic powders, carbon black, but the present invention is not limited thereto. 
     Therefore, the effects of the present invention are enhancement of heat dissipation and electromagnetic shielding of the stacking package structure, thereby enhancing the stability and life time of the chips. To sum up, the technical features of the present invention is the metal base mounted over the first chip and the second chip to provide optimum effects in heat dissipation and electromagnetic shielding, thereby enhancing the stability of the package structure. Furthermore, a heat sink of the present invention can be directly formed on the lower surface of the metal base to enhance the heat dissipation of the package structure. Besides, the metal layer of the present invention can be formed on the substrate to provide a preferable electromagnetic shielding to avoid interference of magnetic field and enhance the stability of the package structure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  shows a sectional schematic diagram of a conventional multichip stacking package structure. 
         FIG. 2  shows a sectional schematic diagram of a metal top stacking package structure according to Example 1 of the present invention. 
         FIG. 3A ˜ 3 H show a process flow schematic diagram of a metal top stacking package structure according to Example 1 of the present invention. 
         FIG. 4  shows a flow diagram of a method for manufacturing the metal top stacking package structure according to Example 5 of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Hereinafter, the actions and the effects of the present invention will be explained in more detail via specific examples of the invention. However, these examples are merely illustrative of the present invention and the scope of the invention should not be construed to be defined thereby. 
     Example 1 
     Please refer to  FIG. 3 ,  FIG. 3  shows a process flow schematic diagram of a metal top stacking package structure according to Example 1 of the present invention; and please refer to  FIG. 2 ,  FIG. 2  shows a sectional schematic diagram of a metal top stacking package structure according to Example 1 of the present invention. Please refer to  FIG. 3A , first, a metal base  20  including an upper surface  201  and a lower surface  203  is provided, and a plurality of die receiver cavities  202  are formed in the upper surface  201 . Secondly, please refer to  FIG. 3B , a plurality of first chips  22  are fixed on these die receiver cavities  202  by a plurality of the first adhesion layers  21 . Please refer to  FIG. 3C , these first chips  22  are electrically connected with the metal base  20  by a plurality of first electrically connecting wires  23  to input and output signals. Further, a second encapsulate material  24 ′ is formed in these die receiver cavities  202  of the metal base  20  and surrounds these first adhesion layers  21 , these first chips  22  and these first electrically connecting wires  23 . Moreover, these die receiver cavities  202  are cut, as shown in  FIG. 3D . Further, please refer to  FIG. 3E , a substrate with an upper surface  251  is provided, and a plurality of second chips  26  are fixed on the upper surface  251  of the substrate  25  by a plurality of the second adhesion layers  21 ′. Besides, please refer to  FIG. 3F , these second chips  26  are electrically connected to the substrate  25  by a plurality of the second electrically connecting wires  23 ′ to input and output signals; and a plurality of connecting components  27  are formed on the upper surface  251  of the substrate  25 . Then please refer to  FIG. 3G , the upper surface  201  of the metal bases  20  is connected with the substrate  25  by these connecting components  27 . Finally, please refer to  FIG. 3H , a first encapsulate material  24  is formed on the substrate  25  and surrounds the metal base  20 , these first adhesion layers  21 , these second adhesion layers  21 ′, these first chips  22 , these second chips  26 , these first electrically connecting wires  23 , these second electrically connecting wires  23 ′ and these connecting components  27 , and the lower surface of the metal base is exposed. 
     Example 2 
     The metal top stacking package structure of Example 2 of the present invention is substantially the same as the above Example 1, except that the second encapsulate material  24 ′ is formed in the receiver cavity of the metal base and surrounds these first adhesion layers, these first chips and these first electrically connecting wires, and the first encapsulate material is formed on the substrate and surrounds the metal base, the first chip, the second chip, the first adhesion layer, the second adhesion layer, the first electrically connecting wires, the second electrically connecting wires, and the connecting components; wherein the lower surface of the metal base is exposed in Example 1 of the present invention. However, in Example 2 of the present invention, the first encapsulate material is formed on the substrate and surrounds the metal base, these first adhesion layers, these second adhesion layers, these first chips, these second chips, these first electrically connecting wires, these second electrically connecting wires and these connecting components after the metal base is electrically connected with the substrate; wherein the lower surface of the metal base is exposed. Namely, Example 1 of the present invention includes the first encapsulate material  24  and the second encapsulate material  24 ′, but Example 2 of the present invention only includes the first encapsulate material  24  to simplify processes and reduce manufacturing cost. 
     Example 3 
     The metal top stacking package structure of Example 3 of the present invention is substantially the same as the above Example 1, except that the lower surface of the metal base of Example 1 is without any component, but the lower surfaces of the metal bases of Example 3 have a heat sink. The heat sink is directly formed on the lower surface of the metal base in Example 3 to enhance heat dissipation of the package structure. Further, the heat sink in Example 3 is a heat spreader, and the material of the heat spreader is a copper material. The heat energy during the working chips is dissipated to the other semiconductor chips or the metal base by the heat sink 
     Example 4 
     The metal top stacking package structure of Example 4 of the present invention is substantially the same as the above Example 1, except that the second adhesion layers are formed on the substrate in Example 1, but the metal layers are formed on the substrate and then the second adhesion layers are formed in Example 4. Further, the materials of the metal layers may be randomly varied based on stacking package conditions and the user&#39;s requirements, and the materials of the metal layer can be a magnesium alloy, an aluminum alloy, a copper alloy, a ferrous alloy, magnesium copper alloy or combinations thereof. Therefore, the package structure has a preferable electromagnetic shielding because of the metal layer, and avoids interference of magnetic field to enhance the stability of the package structure. 
     Example 5 
     Please refer to  FIG. 4 ,  FIG. 4  shows a flow diagram of a method for manufacturing the metal top stacking package structure according to Example 5 of the present invention. First, as shown in step  401 , a metal base including an upper surface and a lower surface is provided, and a plurality of die receiver cavities are formed in the upper surface. Second, as shown in step  402 , a plurality of first chips are fixed on these die receiver cavities by a plurality of first adhesion layers. Further, as shown in step  403 , a plurality of the first electrically connecting wires are coupled these first chips with these metal base; and as shown in step  404 , a second encapsulate material formed in these receiver cavities of the metal base and surrounds these first chips, these first adhesion layers, and the first electrically connecting wires. Besides, as shown in step  405 , a substrate with an upper surface is provided; as shown in step  406 , a plurality of second chips are fixed on the upper surface of the substrate by a plurality of second adhesion layers. Furthermore, as shown in step  407 , a plurality of second electrically connecting wires are coupled these second chips with the substrate; as shown in step  408 , a plurality of connecting components are formed on the upper surface of the substrate, and the upper surface of the metal base connects with the substrate by the connecting components. Finally, as shown in step  409 , a first encapsulate material is formed on the substrate and surrounds the metal base, these first adhesion layers, these second adhesion layers, these first chips, these second chips, these first electrically connecting wires, these second electrically connecting wires, the substrate, and the connecting components, and the lower surface of the metal base is exposed. 
     In the metal top stacking package structure and the method for manufacturing the same, the metal base is formed over the first chip and the second chip to provide preferable electromagnetic shielding and the heat dissipation, thereby enhancing stability of the package structure. The heat sink of the present invention can be directly formed on the lower surface of metal base to enhance heat dissipation of the package structure. Besides, the metal layer can be formed on the substrate according to actual product properties to provide preferable electromagnetic shielding and avoid interference of external magnetic field. 
     It should be understood that these examples are merely illustrative of the present invention and the scope of the invention should not be construed to be defined thereby, and the scope of the present invention will be limited only by the appended claims.