Abstract:
A die-stacked package structure, wherein a plurality of dies are stacked on the substrate with a rotation so that a plurality of metallic ends and the metal pad on each die on the substrate can all be exposed; a plurality of metal wires are provided for electrically connecting the plurality of metal pads on the plurality of dies with the plurality metallic ends on the substrate in one wire bonding process; then an encapsulate is provided for covering the plurality of stacked dies, a plurality of metal wires and the plurality of metallic ends on the substrate.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention is a multi-dies stacked package structure, more particularly; it is a zigzag-stacked package structure. 
         [0003]    2. Description of the Prior Art 
         [0004]    In recent years, the semiconductor package process is using three-dimension (3D) package method to have relative large integrated semiconductor or the volume of the memory in the less measure of area. In order to achieve this object, the die stacked method is used to have 3D package structure. 
         [0005]    In the prior art, the stacked method of the dies is used a plurality of dies to stack to each other on one substrate and the wire bonding process is used to electrically connect the dies and the substrate.  FIG. 1   a  is a sectional view showing a zigzag-stacked package structure with similar size of the dies in the prior art. As shown in  FIG. 1   a , the zigzag-stacked package structure  100  includes a circuit substrate  110 , die  120   a , die  120   b , a spacer  130 , a plurality of wires  140  and an encapsulated material  150 . The circuit substrate  110  includes a plurality of pads and the die  120   a  and die  120   b  respectively includes a plurality of pads  122   a  and  122   b . The pads  122   a  and  122   b  are arranged around the die  120   a  and  120   b  in a peripheral type. The die  120   a  is disposed on the circuit substrate  110  and the die  120   b  is disposed between the spacer  130  and the top of the die  120   a . Two ends of the wires  140  are connected to pads  112  and  122   b  by a wire bonding process and the die  120   b  is electrically connected to the circuit substrate  110 . The encapsulated material  150  is disposed on the circuit substrate  110  and covering the wires  140 , the die  120   a  and  120   b.    
         [0006]    Because the pads  122   a  and  122   b  are arranged on the die  120   a  and  120   b  in a peripheral type, the die  120   a  is not able to support the die  120   b . So, in the package process, after the die  120   a  is connected to the circuit substrate  110 , the pads  122   a  on the die  120   a  is connected to the pads  112  on the circuit substrate  110  by a wire bonding process. The spacer  130  is connected to the die  120   a  and the die  120   b  is connected on the spacer  130 , and the pads  122  on the die  120   b  is connected to the pads  112  on the circuit substrate  110  by another one wire bonding process. Obviously, the spacer  130  is disposed between the die  120   a  and  120   b  and there is a distance between the die  120   a  and  120   b  to protect the wires  140 . However, the usage of the spacer  130  causes the difficulty to reduce the thick of the zigzag-stacked package structure  100 . 
         [0007]    Besides, another one zigzag-stacked package structure with different die size is provided in prior art, as the sectional view shown in  FIG. 1B . The zigzag-stacked package structure  10  includes a package substrate  110 , die  120   c , die  120   d , a plurality of wires  140  and an encapsulated material  150 . The circuit substrate  110  includes a plurality of pads  112 . The size of the die  120   c  is bigger than the size of the die  120   d . The die  120   c  and  120   d  respectively includes a plurality of die  122   c  and  122   d . The pads  122   c  and  122   d  are arranged on the die  120   c  and  120   d  in a peripheral type. The die  120   c  is disposed on the package substrate  110  and the die  120   d  is disposed on the die  120   c . Two ends of some of the wires  140  are connected to the pads  112  and  122   c  by wire bonding process and the die  120   c  is able to electrically connect to the circuit substrate  110 . Two ends of the other wires  140  are connected to the pads  112  and  122   d  by wire bonding process and the die  120   d  is able to electrically connect to the circuit substrate  110 . The encapsulated material  150  is disposed on the circuit substrate  110  and covering the wires  140 , the die  120   c  and  120   d.    
         [0008]    Because the die  120   d  is smaller than the die  120   c , the die  120   d  is not able to cover the die  120   c  when the die  120   d  is disposed on the die  120   c . Therefore, the package process is different to the process in  FIG. 1A . The die  120   c  and  120   d  are connected to the package substrate  110  first and then doing one time wire bonding process. When the dies with different size are stacked together to form a zigzag-stacked package structure in prior art, the size of the die on the topper is smaller, therefore the number of the dies is limited. 
         [0009]    According to the two stacked method described above, the spacer  130  used in  FIG. 1A  is not easy to reduce the thick of the zigzag-stacked package structure and the size of the die on the topper has to be smaller in  FIG. 1B  to limit the design and the usage of the dies. According to the problem above, U.S. Pat. No. 6,252,305, U.S. Pat. No. 6,359,340 and U.S. Pat. No. 6,461,897 provides another zigzag-stacked package structure, as shown in  FIG. 1C . Obviously, the package structure uses the dies with the same sizes, therefore there is no spacer  130  used to connect the dies and the substrate. However, during the stacking steps, the dies are stacked to each other by using at least two types of pads. For example, the pads on the first dies are disposed on one side of the first dies and the pads on the second dies are disposed on the two adjacent sides. Besides, the package structure needs the wire bonding process to use in two directions. Therefore, as the structure shown in  FIG. 1C , it would increase the time of wire bonding process and it would cause asymmetrical molding flow during the molding process. The wire in one direction would hit by the transversal molding strength and the connection of the wires is caused the malfunction of the dies. 
         [0010]    Besides, U.S. Pat. No. 6,900,528, U.S. patent No. 20030137042A1, U.S. patent No. 20050029645A1 and U.S. patent No. 20060267173A1 disclosed another zigzag-stacked package structure. Obviously, the height between the dies is used to replace the spacer to increase the density of the package structure. However, there are some problems in the manufacture of the package structure. After two dies are connected together, the first time of the wire bonding process is in proceeding, do the connection of another two dies and the second time of the wire bonding process. When the number of dies is increased, the package process is become more and more complicated. 
       SUMMARY OF THE INVENTION 
       [0011]    According to the drawbacks and the problems of prior art described above, there is a zigzag-stacked package structure is used in the present invention to stack the dies with similar size in a three-dimension package structure. 
         [0012]    The main object of the present invention is to provide a zigzag-stacked package structure with higher package density and thinner thickness. 
         [0013]    Another object of the present invention is to provide a zigzag-stacked package structure with balance molding effect during the molding process. 
         [0014]    Another object of the present invention is to provide a zigzag-stacked package structure including a bus bar to have better flexibility of circuit design and the reliability. 
         [0015]    According the objects described above, the present invention provides a zigzag-stacked package structure. The zigzag-stacked package structure includes a lead frame, a zigzag-stacked package structure and an encapsulated material. The lead frame includes a plurality of inner leads, a plurality of outer leads and a die paddle and wherein the die paddle is disposed between the inner leads and a height difference formed between the die paddle and the inner leads. The zigzag-stacked structure is connected on the die paddle and the zigzag-stacked structure includes a plurality of first dies and a plurality of second dies, which are alternatively and respectively stacked to each other, and the first dies, the second dies and the inner leads are electrically connected. The encapsulated material covering the zigzag-stacked structure and the lead frame, and the outer leads are extended over the encapsulated material. Wherein one side of an active surface on each of the first dies and the second dies structure respectively includes a plurality of pads disposed thereon and the other side of an active surface on each of the first dies and the second dies structure respectively includes a plurality of pads disposed thereon. 
         [0016]    The present invention also provides a zigzag-stacked package structure. The zigzag-stacked package structure includes a lead frame, a zigzag-stacked structure and an encapsulated material. The lead frame includes a plurality of inner leads, a plurality of outer leads, at least one bus bar and a die paddle, and wherein the die paddle is disposed between the inner leads and a height difference formed between the die paddle and the inner leads, the bus bar is disposed between the inner leads and the die paddle. The zigzag-stacked structure is connected on the die paddle and the zigzag-stacked structure includes a plurality of first dies and a plurality of second dies, which are alternatively and respectively stacked to each other, and the first dies, the second dies and the inner leads are electrically connected. The encapsulated material covers the zigzag-stacked structure and the lead frame, and the outer leads are extended over the encapsulated material. One side of an active surface on each of the first dies and the second dies structure respectively includes a plurality of pads disposed thereon and the other side of an active surface on each of the first dies and the second dies structure respectively includes a plurality of pads disposed thereon. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein: 
           [0018]      FIGS. 1A˜1C  are views in prior art. 
           [0019]      FIGS. 2A and 2C  are top views of the die structure in the present invention. 
           [0020]      FIGS. 2B and 2D  are sectional views of the die structure in the present invention. 
           [0021]      FIG. 2E  is a section view of a zigzag-stacked structure in the present invention. 
           [0022]      FIGS. 3A˜3C  are views of a manufacture procedure of a redistribution layer in the present invention. 
           [0023]      FIGS. 4A˜4B  are section views of the wire bonding are of the redistribution layer in the present invention. 
           [0024]      FIG. 5  is a sectional view of a zigzag-stacked structure with a redistribution layer in the present invention. 
           [0025]      FIG. 6  is a sectional view of a zigzag-stacked structure in another embodiment of the present invention. 
           [0026]      FIG. 7  is a top view of a zigzag-stacked structure in the present invention. 
           [0027]      FIG. 8  is a sectional view of a zigzag-stacked structure in the present invention. 
           [0028]      FIG. 9  is a top view of a zigzag-stacked structure with a bus bar in another embodiment of the present invention. 
           [0029]      FIG. 10  is a sectional view of a zigzag-stacked structure with a bus bar in another embodiment of the present invention. 
           [0030]      FIG. 11  is top view of a zigzag-stacked structure in another embodiment of the present invention. 
           [0031]      FIG. 12  is a sectional view of a zigzag-stacked structure in another embodiment of the present invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0032]    The detailed description of the present invention will be discussed in the following embodiments, which are not intended to limit the scope of the present invention, but can be adapted for other applications. While drawings are illustrated in details, it is appreciated that the quantity of the disclosed components may be greater or less than that disclosed, except expressly restricting the amount of the components. 
         [0033]    The semiconductor package structure in these years is to package a wafer in front end process to do the thinning execution. The thinning process is to grind the die with the size between 2˜20 mils and then do the process of coating or printing a polymer on the reverse side of the die. The material of polymer is a resin, such as a B-Stage resin. After a baking or photo-lighting process, the polymer is become a sticky gluing material. After the baking process, a removable tape is stuck on the polymer. The wafer is on sawing process, the wafer is cut to be a plurality of dies. At final, each of the dies is connected on the substrate and the dies are stacked together to form a stacked package. 
         [0034]    First, please refer to  FIG. 2A  and  FIG. 2B ,  FIG. 2A  and  FIG. 2B  are plan view and sectional view of die  200  shown in previous description. As shown in  FIG. 2A , the die  200  includes an active surface  210  and a reverse surface  220  corresponding to the active surface  210 . There is an adhesive layer  230  formed on the reverse surface  220  of the die  200 . It should be noted that the adhesive layer  230  in the present invention is the sticky gluing material described above, but not limited. 
         [0035]    The object of the adhesive layer  230  is to connect the lead frame or the die  200 . Therefore, any package structure with this adhesive material, such as die attached film, is included in the present invention. Besides, in the embodiment of the present invention, there is a plurality of pads  240  on the active surface  210  of the die  200  and the pads  240  are disposed on one side of the die  200 . There are a plurality of pads  240  on the active surface  210  of the other die  20  and the pads  240  are disposed the other side of the die  200 . It should be noted that the pads  240  on the die  20  and die  200  are disposed on the responding sides, as shown in  FIG. 2C  and  FIG. 2D . Therefore, a zigzag-stacked structure  30  is formed, as shown in  FIG. 2E . When the zigzag-stacked structure  30  is formed in the present invention, the stacked area between dies is determined by the number of the dies. For example, the two dies  20   a  and  200   a  on the bottom layer are connected by the adhesive layer  230 , the stacked area of the die  20   a  and die  200   a  is more than a half of the stacked area of die  20   a  or  200   a . The larger stacked area is in the topper level of the die. Each of the die is formed at the edge line  260  of the wire bonding region  250 . Therefore, a step like die stacked package structure is formed. The pads disposed on the die are not covered by the top die. Besides, it should be noted that the edge line  260  actually is not existed on the die and it is just a reference line. In an embodiment, the size of the die  20  or die  200  is about 10 mm*13 mm*75 um and the thick of the adhesive layer  230  on the reverse surface of the die is about 60 um. The thickness of the package substrate used to support the zigzag-stacked structure is about 200 um 250 um. According to the size of the package structure of the die, the biggest overhand wide of the zigzag-stacked structure is about 1 mm for a six levels dies and less than 1.5 mm for an eight levels dies. It should be noted that it is not limited for the size of the zigzag-stacked structure to describe above. As long as the zigzag-stacked structure is formed according to the description above is included in the present invention. For example a two levels zigzag-stacked structure and a four levels zigzag-stacked structure. 
         [0036]    Now it is an embodiment of the present invention for a die  200  or a die  20  including a plurality of pads disposed thereon. In the present invention, it is using a redistribution layer (RDL) to put the pads of the die on one side of the die to form a zigzag-stacked structure. The steps to form the redistribution layer are described in the following. 
         [0037]      FIGS. 3A˜3C  are views showing manufacture steps of the redistribution layer of the die in the present invention. As shown in  FIG. 3A , a die  310  is provided and it designs a wire bonding region  320  on one side of the die  310  and the pads  312  on the active surface of the die are divided into first pads  312   a  and second pads  312   b . The first pads  312   a  are disposed within the wire bonding region  320  and the second pads  312   b  are disposed outside of the wire bonding region  320 . Now please refer to  FIG. 3B , there is a protective layer  330  is formed on the die  310  and the protective layer  330  includes a plurality of openings used to expose the first pads  312   a  and the second pads  312   b . Then, a redistribution layer  340  is formed on the protective layer  330 . The redistribution layer  340  includes a plurality of wires  342  and a plurality of third pads  344 . The third pads  344  are disposed within the wire bonding region  320  and the wires  342  are extended from the second pads  312   b  to the third pads  344 . The second pads  312   b  are able to electrically connect the third pads  344 . Besides, the material of the redistribution layer  340  is gold, copper, nickel, titanium tungsten, titanium and any other conductive metals. Now please refer to  FIG. 3C , after forming the redistribution layer  340 , the second protective layer  350  covers the redistribution layer  340  to form the structure of the die  300 . The second protective layer  350  includes a plurality of second openings  352  to expose the first pads  312   a  and the third pads  344 . 
         [0038]    It should be noted that the first pads  312   a  and the second pads  312   b  are arranged on the active surface of the die  310  in a peripheral type. The first pads  312   a  and the second pads  312   b  are able to be arranged on the active surface of the die  310  in an area array type or any other different types. The second pads  312   b  are electrically connected to the third pads by wires  342 . Besides, the arranged method of the third pads  344  is not limited in the present embodiment. Although the third pads in  FIG. 3B  and the first pads  312   a  are arranged in two lines and line up along one side of the die  310 . The third pads  344  and the first pads  312   a  are able to arrange in single line, multi lines or any other types within the wire bonding region  320 . 
         [0039]    Please refer to  FIGS. 4A and 4B , those are sectional views according to the sectional line A-A′ and B-B′ in  FIG. 3C . As the description in  FIG. 3C , the die  300  includes die body  310  and the redistribution layer  400 . The redistribution layer  400  is composed by the first protective layer  330 , the redistribution layer  340  and the second protective layer  350 . The die body  310  includes the wire bonding region  340   a  and the wire bonding region is close to one side of the die body  310 . Besides, the first pads  312   a  are disposed within the wire bonding regions  320  and the second pads  312   b  are disposed outside of the wire bonding region  320 . 
         [0040]    The first protective layer  330  is disposed on the die body  310  and includes a plurality of opening used to expose the first pads  312   a  and the second pads  312 . The redistribution layer  340  is disposed on the first protective layer  330  and extended from the second pads  312   b  to the wire bonding regions. The redistribution layer  340  includes a plurality of third pads  344  disposed within the wire bonding region  320 . The second protective payer  350  includes a plurality of second openings  352  to expose the first pads  312   a  and the third pads  344 . Obviously, the first pads  312   a  and the third pads  344  are able to be disposed the other side of the die by the same package process. 
         [0041]      FIG. 5  is a view showing a zigzag-stacked structure in the present invention. The zigzag-stacked structure  50  is composed by stacking a plurality of dies  500 . For example, there are four dies stacked to each other and each of the dies includes a redistribution layer  400 . Therefore, the pads  312   b  on the dies are disposed on the wire bonding region  320  of the dies to form the zigzag-stacked structure  50 . The stacked method of the zigzag-stacked structure  50  is the same as the zigzag-stacked structure  30  described above, the detailed description was omitted. Besides, there is an adhesive layer  230 , such as polymer, used to connect the dies  500  and form the zigzag-stacked structure. 
         [0042]    Besides the zigzag-stacked structures in the present invention are described above, the zigzag-stacked structure  30  and  50 , the die  20  is able to stack on the dies  500  with the redistribution layer  400  to form another kind of the zigzag-stacked structure. As shown in  FIG. 6 , there are six dies stacked together. Because the stacked method of the zigzag-stacked structure  70  is the same as the stacked method of the zigzag-stacked structure  30  and  50 , so the detail description of the stacked method is omitted. It should be noted that the die  20  and the die  500  in the present embodiment is not limited to specify which die on top or which die on bottom. As long as the zigzag-stacked structure is formed by the die  20  or die  500  is included in the present invention. Also, it should be noted that the number of dies to form the zigzag-stacked structure is not limited in the present invention. For example, there are four dies stacked together as shown in  FIG. 5  and there are six dies stacked together as shown in  FIG. 6 . Of course, it can be another kind of composition to form the zigzag-stacked structure by satisfying the description above is includes in the present invention. 
         [0043]    There is another zigzag-stacked structure provided according to the zigzag-stacked structure  30 ,  50  and  70  described above. In the following description, the zigzag-stacked structure  50  is used but the zigzag-stacked structures  30  and  70  are also suitable in the following description. 
         [0044]      FIG. 7  is a plan view showing the zigzag-stacked package structure in the present invention. As shown in  FIG. 7 , the zigzag-stacked package structure includes a lead frame  600  and a zigzag-stacked structure  50 A. The lead frame  600  includes a plurality of inner leads  610 , a plurality of outer leads (not shown) and a die paddle  620 . The die paddle  620  is disposed between the corresponding inner leads  610 . There is a height difference formed between the corresponding inner leads  610  and the die paddle  620 . In this embodiment, the zigzag-stacked structure  50 A is disposed and connected on the die paddle  620  by an adhesive layer  230 . The adhesive layer  230  in the present invention is a sticky gluing material as described above but not limited. The adhesive layer  230  is used to connect the zigzag-stacked structure  50 A and the die paddle  620 . Therefore, any package structures with the same function of the adhesive material, such as die attached film, are includes in the present invention. It should be noted that, in the real package process, there are two ways to form the zigzag-stacked package structure. One is to stack a plurality of dies first and then connect with the lead frame. The other one is to connect the die on the bottom and the lead frame and then sequentially stack the dies one after another. No matter what kind of the package method to form the zigzag-stacked structure  50 A, the wires  640  are used to connect the zigzag-stacked structure  50 A and the inner leads  610  of the lead frame  600  after stacking the dies. Obviously, the zigzag-stacked package structure in the present invention is to connect the dies and the lead frame first and then do the wire bonding process to simplify the package procedure. It should be noted that the pads disposed on the dies are not covered by the top die in each of the zigzag-stacked structures in the present invention. Therefore, the dies are able to connect to the lead frame and then do the wire bonding process. Because the procedure that the wire  640  is used to connect the dies and the lead frame  600  is a prior art, the detail description is omitted. 
         [0045]      FIG. 8  is a sectional view showing a zigzag-stacked package structure in the present invention (according to the sectional line AA in  FIG. 7 ). As shown in  FIG. 8 , the lead frame  600  is stacked with six dies  500  to form the zigzag-stacked package structure and is connected by a plurality of wires  640 . The lead frame  600  includes a plurality of corresponding inner leads, a plurality of outer leads and a die paddle  620 . The die paddle  620  is disposed between the corresponding inner leads  610  and a height difference is formed between the die paddle  602  and the inner leads  610 . One end of the wire  640   a  is connected to the first pads  312   a  of the die  500   a  or the third pads  344  (as the first pads  312   a  or the third pads  344  in  FIG. 3 ). The other end of the wires  640  is connected to the first pads  312   a  of the die  500   b  or the third pads  344 . Then, one end of the wire  640   b  is connected to the first pads  312   a  of the die  500   b  or the third pads. The other end of the wire  640   b  is connected to the first pads  312   a  of the die  500   c  or the third pads  344 . The wire  640   c  is sued to electrically connect the die  500   a  and the corresponding inner lead  610  of the lead frame  600 . The steps described above are repeated to connect the die  500   d ,  500   e  and  500   f  by the wire  640   d  and  640   e . Finally, the die  500   d  is electrically connected to the corresponding inner leads  610  of the lead frame by the wire  640   f . Therefore, the wires  640   a ,  640   b ,  640   c ,  640   d ,  640   e  are  640   f  are connected and the dies  500   a ,  500   b ,  500   c ,  500   d ,  500   e  and  500   f  are connected to the lead frame  600 . The materials of the wires  640  are gold. Obviously, the method to form the zigzag-stacked package structure in the present invention is to connect the dies and the lead frame first and then do the wire bonding process to simplify the package procedures. 
         [0046]    The molding process is used to form the encapsulated material  90  to cover the zigzag-stacked structure  50 A and the inner leads  610  and the die paddle  620  in the lead frame  600 . The molding process is done by a pattern, so the molding flow is able to flow into the two sides of the inner lead. The zigzag-stacked structure  30 , the zigzag-stacked structure  50  or  50 A or the zigzag-stacked structure  70  are stacked crossly, it is able to form the symmetrical structure, even though the number of dies are different, such as the zigzag-stacked structure  30  formed by eight dies  200 , the zigzag-stacked structure  50  formed by four dies  500  and the zigzag-stacked structure  70  formed by six dies. Therefore, when the molding flow is flowed into the two sides of the inner leads, it balances the molding flow in two sides of the inner leads. The zigzag-stacked package structure is able to have very good reliability. Besides, the inner lead  610  of the lead frame  600  are existed in the present invention, the vertical distance (d 1 ) between the top edge surface  910  of the encapsulated material  90  and the die  500   f  and the vertical distance (d 2 ) between the bottom edge of the die paddle  620  and the bottom edge of the encapsulated material  90  are the same. When the molding process is in proceeding, the molding flow on the die  500   f  and the bottom edge of the die paddle  620  are same to form the balance package structure in this embodiment. 
         [0047]      FIG. 9  is a plan view showing a zigzag-stacked package structure according to another embodiment of the present invention. As shown in  FIG. 9 , the zigzag-stacked package structure includes lead frame  600  and a zigzag-stacked structure  50 A. The lead frame  600  includes a plurality of inner leads  610 , a plurality of outer leads (not shown) and a die paddle  620 . The die paddle  620  is disposed between the corresponding inner leads  610  and a height difference is formed between the die paddle  620  and the corresponding inner leads  610 . In this embodiment, the zigzag-stacked structure  50 A is disposed and connected on the die paddle  620  by the adhesive layer  230 . The adhesive layer  230  in the present invention is a sticky gluing material but not limited. The adhesive layer  230  is used to connect the zigzag-stacked structure  50 A and the die paddle  620 . Therefore, any package structures with the same function of the adhesive material, such as die attached film, are included in the present invention. The wires  640  are used to connect the zigzag-stacked structure  50 A and the inner leads  610  of the lead frame  600  after stacking the dies. Obviously, the zigzag-stacked package structure in the present invention is to connect the dies and the lead frame first and then do the wire bonding process to simplify the package procedure. It should be noted that the pads disposed on the dies are not covered by the top die in each of the zigzag-stacked package structures in the present invention. Therefore, the dies are able to connect to the lead frame and then do the wire bonding process. Because the procedure that the wires  640  is used to connect the dies and the lead frame  600  is a prior art, the detail description is omitted. 
         [0048]    Still refer to  FIG. 9 ; the lead frame  600  of the zigzag-stacked package structure in this embodiment further includes a bus bar  630  disposed between the die paddle  620  and the corresponding inner leads  610 . The height of the bus bar within the lead frame  600  is the same as the height of the die paddle  620  and the inner leads  610  or the height of the bus bar is between the height of the die paddle  620  and the height of the inner leads  610 . The bus bar  630  is formed in a bar-like arrangement or ring-like arrangement. Besides, as the description above, the pads  312 / 344  within the within the wire bonding region  320  of the die  500  is a single line arrangement or a double line arrangement, it is not limited in the present invention. The bus bar  630  is also included in prior art, the detail description is omitted. 
         [0049]      FIG. 10  is a sectional view of a zigzag-stacked package structure with a bus bar according to the present invention (according to the section line BB in  FIG. 9 ). As shown in  FIG. 10 , the lead frame  600  is stacked with six dies  500  to form the zigzag-stacked package structure and is connected by a plurality of wires  640 . The lead frame  600  includes a plurality of corresponding inner leads  610 , a plurality of outer leads (not shown) and a die paddle  620 . The die paddle  620  is disposed between the corresponding inner leads  610  and a height difference is formed between the die paddle  602  and the inner leads  610 . The bus bar  630  is disposed between the inner lead  610  and the die paddle  620 . One end of the wire  640   a  is connected to the first pads  312   a  of the die  500   a  or the third pads  344  (as the first pads  312   a  or the third pads  344  in  FIG. 3 ). The other end of the wire  640   a  is connected to the first pads  312   a  of the die  500   b  or the third pads  344 . Then, one end of the wire  640   b  is connected to the first pads  312   a  of the die  500   b  or the third pads. The other end of the wire  640   b  is connected to the first pads  312   a  of the die  500   c  or the third pads  344 . The wire  640   c  is used to electrically connect the die  500   a  and the corresponding inner lead  610  of the lead frame  600 . The steps described above are repeated to connect the die  500   d ,  500   e  and  500   f  by the wire  640   d  and  640   e . Finally, the die  500   d  is electrically connected to the corresponding inner leads  610  of the lead frame by the wire  640   f . Therefore, the wires  640   a ,  640   b ,  640   c ,  640   d ,  640   e  are  640   f  are connected and the dies  500   a ,  500   b ,  500   c ,  500   d ,  500   e  and  500   f  are connected to the lead frame  600 . The materials of the wires  640  are gold. Besides, the lead frame  600  in the embodiment includes a bus bar  630  and the height of the bus bar  630  is the same as the height of the inner lead  610 . Therefore, during the connection steps of the wires  640 , by the need of the connection of the circuit, some of the wires  640  are optionally connected to the bus bar  630 . Therefore, the bus bar  630  of the lead frame  600  is used to be a connective point, such as a power connective point, a grounding point or a signal connective point. The bus bar  630  is useful in circuit design. The bus bar  630  is disclosed in prior art, the detail description is omitted. 
         [0050]    At final, the molding process is used to form the encapsulated material  90 . This embodiment is the same as the embodiment in  FIG. 8 , when the molding flow is flowed into two sides of the inner lead to balance the two sides of the molding flow. The inner lead  610  of the lead frame  600 , the die paddle  620  and the bus bar  630  are existed in the present invention, the vertical distance (d 1 ) between the top edge surface  910  of the encapsulated material  90  and the die  500   f  and the vertical distance (d 2 ) between the bottom edge of the die paddle  620  and the bottom edge of the encapsulated material  90  are the same. When doing the molding process, the molding flow on the die  500   f  and the bottom edge of the die paddle  620  are same to form the balance package structure in this embodiment. 
         [0051]      FIG. 11  is a plan view showing another embodiment showing a zigzag-stacked package structure of the present invention. As shown in  FIG. 11 , the zigzag-stacked package structure includes circuit substrate  800  and the zigzag-stacked structure  70 . The substrate is used to support the zigzag-stacked structure ( 30 ,  50 ,  50 A or  70 ). The wires  640  are used to connect the metal ends or metal lines  810  on the circuit substrate  800  and the zigzag-stacked structure  70  in order to connect the external circuit. The adhesive material  230  described above is also used to connect the zigzag-stacked structure  70  and the circuit substrate  800 . The material of the circuit substrate  800  is a printed circuit board (PCB), ceramic substrate or a substrate with a core layer made by BT resin or FR-4 resin. Besides, in order to connect the external circuit, the reverse surface of the substrate, the surface used to connect the zigzag-stacked structure  70 , includes the metal points or the metal lines  810  disposed thereon by redistribution layer (RDL) or through-hole process. Therefore, the solder ball is used to connect, such as a ball grid array (BGA) package structure. Obviously, the pads on the dies are not covered by the topper dies in the zigzag-stacked package structure of the present invention. After the dies are connected to the circuit substrate  800 , the wire bonding process is proceeding to simplify the package procedures. 
         [0052]      FIG. 12  is a section view showing a zigzag-stacked package structure of the present invention (according to the sectional line CC in  FIG. 11 ). As shown in  FIG. 12 , a plurality of the wires  640  are used to connect the package substrate  800  and the zigzag-stacked structure  70 . The wires  640  are used to electrically connect the dies  500  on the zigzag-stacked structure  70  and the metal ends  810  on the package substrate  800 . The materials of the wires  640  are gold. The molding process is used to form the encapsulated material  90  covering the zigzag-stacked structure  70  and the circuit substrate  800 .