Abstract:
A manufacturing method of package carrier is provided. A first copper foil layer, a second copper foil layer on the first foil layer, a third copper foil layer and a fourth foil layer on the third foil layer are provided. The second copper foil layer is partially bonded the fourth copper foil layer by an adhesive gel so as to form a substrate of which the peripheral region is glued and the effective region is not glued. Therefore, the thinner substrate can be used in the following steps, such as patterning process or plating process. In addition, the substrate can be extended be the package carrier structure with odd-numbered layer or even-numbered layer.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of Taiwan application serial no. 98145638, filed on Dec. 29, 2009. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of specification. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a method of manufacturing a semiconductor structure, and more particularly to a method of manufacturing a package carrier. 
     2. Description of Related Art 
     In the fabrication of semiconductors, chip package carrier is one of the most common used package components. The chip package carrier, for example, is a multi-layered circuit board, in which a plurality of circuit layers and a plurality of dielectric layers are alternately stacked. Each of the dielectric layers is disposed between two adjacent circuit layers, and the circuit layers are electrically connected through the plating through hole (PTH) or via. Since a chip package carrier has the advantages of dense wiring, compact assembly and good electrical performance, it is most widely used in the chip package structure. 
     Typically, the structure of the multi-layered circuit board commonly formed by the build-up method or the laminating method so that it has the features of high wiring density and small pitch. Since the rigidity of the ultra-thin substrate is poor, it is necessary to provide a metal (such as aluminum substrate or copper substrate) as a supporting carrier. Then, mass of gel are coated on the metal, and then the plurality of circuit layers and the plurality of dielectric layer are alternatively arranged on the two opposite surfaces of the metal. Finally, the gel is removed so that the circuit layers and the dielectric layers are separated from the metal to form two multi-layered circuit boards separated from each other. Moreover, as for forming the plating through hole or via in the multi-layered circuit board, after a dielectric layer is formed, a blind via is formed to expose the circuit layer underneath the dielectric layer. Then, by using copper plating method, a copper layer is plated in the blind via and on the dielectric layer to form connecting layers and the plating through hole or via. 
     Since, conventionally, the metal is provided to be the supporting carrier of the copper foil and the cost of the metal is relatively high, the cost for manufacturing the multi-layered circuit board is high. Also, the mass of gel is used to fix the copper foil on the metal so that it is difficult to remove the gel and the manufacturing yield is hardly improved. Moreover, as for the circuit layer formed by the copper plating method, the thickness uniformity of the copper layer is poor so that when the required thickness of the circuit layer is small, it is necessary to perform the thinning process (such as etching process) to decrease the thickness of the circuit layer. Thus, the number of the process steps for manufacturing the multi-layered circuit board is increased and the manufacturing yield of the multi-layered circuit board is decreased. 
     SUMMARY OF THE INVENTION 
     The present invention provides a method for forming a package carrier capable of simplifying the manufacturing steps, decreasing the manufacturing cost, increasing the manufacturing yield and further increasing the product reliability. 
     The present invention provides a method for forming a thin copper laminate without carrier and be handled on process. A first copper foil layer, a second copper foil layer on the first copper foil layer, a third copper foil layer and a fourth copper foil layer on the third copper foil layer are provided. The second foil layer is partially glued to the fourth copper foil layer by an adhesive gel or is partially attached to the fourth copper foil layer by welding copper foil. A plurality of first through holes extending from the first copper foil layer to the third copper foil layer are formed. A first dielectric layer and a first conductive layer disposed thereon are compressed on the first copper foil layer, and a second dielectric layer and a second conductive layer disposed thereon are compressed on the third copper foil layer. The first dielectric layer and the second dielectric layer face to the first copper foil layer and the third copper foil layer respectively, and portions of the first dielectric layer and the second dielectric layer fill in the first through holes. The first conductive layer and the second conductive layer are patterned to form a first circuit layer and a second circuit layer. Then, a third dielectric layer and a fifth copper foil layer disposed thereon are compressed on the first circuit layer and the adhesive gel is removed to from a first carrier unit. A plurality of first conductive blind via structures connecting the fifth copper foil layer and the first circuit layer are formed, and a plurality of second conductive blind via structures connecting the first copper foil layer and the first circuit layer are formed. Thin coppers laminate without carrier and can be handled on process. 
     In one embodiment of the present invention, the thickness of the second copper foil layer is substantially larger than the thickness of the first copper foil layer. Thickness of the first copper foil layer is substantially equal to the thickness of the third copper foil layer. The thickness of the second copper foil layer is substantially equal to the thickness of the fourth copper foil layer. 
     In one embodiment of the present invention, the adhesive gel includes cyanoacrylate (usually referred as an instant glue) or polypropylene resin (i.e. PP gel). 
     In one embodiment of the present invention, a method of forming the through holes includes mechanical drilling. 
     In one embodiment of the present invention, a sum of the thickness of the first dielectric layer and the thickness of the first conductive layer is substantially larger than a sum of the thickness of the first copper foil layer and the thickness of the second foil layer. A sum of the thickness of the second dielectric layer and the thickness of the second conductive layer is substantially larger than a sum of the thickness of the third copper foil layer and the thickness of the fourth copper foil layer. 
     In one embodiment of the present invention, before the step of patterning the first conductive layer and the second conductive layer, the method of forming the package carrier further comprises forming a plurality of second through holes extending from the first conductive layer to the second conductive layer. 
     In one embodiment of the present invention, the third dielectric layer and the fifth copper foil layer disposed on the third dielectric layer are compressed on the first circuit layer after the adhesive gel is removed. 
     In one embodiment of the present invention, the third dielectric layer and the fifth copper foil layer disposed on the third dielectric layer are compressed on the first circuit layer before the adhesive gel is removed. 
     In one embodiment of the present invention, the step of compressing the third dielectric layer and the fifth copper foil layer disposed on the third dielectric layer on the first circuit layer further comprises compressing a fourth dielectric layer and a sixth copper foil layer disposed thereon on the second circuit layer. 
     In one embodiment of the present invention, a method of removing the adhesive gel includes a mechanical drilling or a milling machine process. 
     In one embodiment of the present invention, after the step of removing the adhesive gel, the method for forming the package carrier further comprises removing the second copper foil layer. 
     In an embodiment of the present invention, a method of removing the second copper foil layer includes a lift-off method. 
     In one embodiment of the present invention, the first carrier unit comprises the fifth copper foil layer, the third dielectric layer, the first circuit layer, the first dielectric layer and the first copper foil layer, and the method for forming the first conductive blind via structures and the second conductive blind via structures is described as follows. A mechanical drilling is performed on the fifth copper foil layer and the first copper foil layer so as to form a plurality of first blind via extending from the fifth copper foil layer to the first circuit layer and a plurality of second blind vias extending from the first copper foil layer to the first circuit layer. The first blind vias and the second blind vias expose a portion of the first circuit layer. A chemical copper layer is formed in the first blind vias and the second blind vias, wherein the chemical copper layer connects the fifth copper foil layer and the first circuit layer and connects the first copper foil layer and the first circuit layer. A first patterned dry film photoresist layer is formed on the fifth copper foil layer and a second patterned dry film photoresist layer is formed on the first copper foil layer. The first patterned dry film photoresist layer at least exposes the first blind vias and the second patterned dry film photoresist layer at least exposes the second blind vias. An copper plating copper layer is formed at least in the first blind vias and the second blind vias, wherein the copper plating copper layer fills up the first blind vias and the second blind vias and covers a portion of the chemical copper layer. The first patterned dry film photoresist layer and a portion of the fifth copper foil layer under the first patterned dry film photoresist layer, and the second patterned dry film photoresist layer and a portion of the first copper foil layer under the second patterned dry film photoresist layer are removed to expose a portion of the third dielectric layer and a portion of the first dielectric layer so as to form the first conductive blind via structures in the first blind vias and the second conductive blind via structures in the second blind vias. 
     In one embodiment of the present invention, the mechanical drilling includes a laser drilling. 
     In one embodiment of the present invention, the method for forming the chemical copper layer includes an electroless plating process. 
     In one embodiment of the present invention, the method for removing the first patterned dry film photoresist layer and a portion of the fifth copper foil layer under the first patterned dry film photoresist layer, and the second patterned dry film photoresist layer and a portion of the first copper foil layer under the second patterned dry film photoresist layer includes an etching process. 
     In one embodiment of the present invention, after the first patterned dry film photoresist layer and a portion of the fifth copper foil layer under the first patterned dry film photoresist layer, and the second patterned dry film photoresist layer and a portion of the first copper foil layer under the second patterned dry film photoresist layer are removed, the method for forming the package carrier further comprises the steps described as follows. A first protecting layer is formed on the third dielectric layer and a second protecting layer is formed on the first dielectric layer. The first protecting layer covers the third dielectric layer and the first conductive blind via structures exposed by the third dielectric layer, and the second protecting layer covers the first dielectric layer and the second conductive blind via structures exposed by the first dielectric layer. 
     In one embodiment of the present invention, the method of forming the first protecting layer and the second protecting layer includes a screen printing. 
     In one embodiment of the present invention, after the step of forming the first protecting layer and the second protecting layer, the method of forming the package carrier further comprises performing a polishing process to remove a portion of the first protecting layer until the first conductive blind via structures are exposed and to remove a portion of the second protecting layer until the second conductive blind via structures are exposed. The rest portion of the first protecting layer and the rest portion of the second protecting layer are removed. 
     In one embodiment of the present invention, after the step of forming the first conductive blind via structures and the second conductive blind via structures, the method for forming the package carrier further comprises forming a first solder mask layer on the third dielectric layer, wherein the first solder mask layer has a plurality of first openings exposing the first conductive blind via structures. A second solder mask layer is formed on the first dielectric layer, wherein the second solder mask layer has a plurality of second openings exposing the second conductive blind via structures. 
     Accordingly, in the present invention, the second copper foil layer is partially bonded the fourth copper foil layer, so that the first copper foil layer, the second copper foil layer, the third copper foil layer and the fourth copper foil layer are bonded to each other. Comparing with the conventional technique, in the package carrier formation method of the present invention, it is not necessary to adopt the metal as the supporting carrier so that the cost for manufacturing the package carrier is decreased. Moreover, the first conductive layer and the second conductive layer are laminated by the compressing process, and then the first circuit layer and the second circuit layer are formed by the patterning method. Therefore, by comparing with the conventional technique that the circuit layers are formed by the copper plating method, the first circuit layer and the second circuit layer have relatively better copper thickness uniformities. 
     In order to make the aforementioned and other features and advantages of the invention more comprehensible, embodiments accompanying figures are described in detail below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
         FIGS. 1A through 1P  are schematic cross-sectional views illustrating a manufacturing method of a package carrier according to one embodiment of the present invention. 
         FIGS. 2A through 2B  are schematic cross-sectional views illustrating the steps of compressing the third dielectric layer and the fifth copper foil layer and removing the adhesive gel according to another embodiment of the present invention. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
       FIGS. 1A through 1P  are schematic cross-sectional views illustrating a manufacturing method of a package carrier according to one embodiment of the present invention. As shown in  FIG. 1A , a first copper foil layer  110   a , a second copper foil layer  110   b  on the first copper foil layer  110   a , a third copper foil layer  110   c  and a fourth copper foil layer  110   d  on the third copper foil layer  110   c  are provided. The second foil layer  110   b  is partially bonded the fourth copper foil layer  100   d  by an adhesive gel  120 . That is, the adhesive gel  120  is disposed between the second copper foil layer  110   b  and the fourth copper foil layer  110   d , and the second copper foil layer  110   b  is partially glued to the fourth copper foil layer  110   d . Moreover, the first copper foil layer  110   a  and the second copper foil layer  110   b  on the first copper foil layer  110   a  can be regarded as a coreless structure layer. Similarly, the third copper foil layer  110   c  and the fourth copper foil layer  110   d  on the third copper foil layer  110   c  can be regarded as a coreless structure layer. 
     In the present embodiment, the thickness of the second copper foil layer  110   b  is substantially larger than the thickness of the first copper foil layer  110   a , and the thickness of the first copper foil layer  110   a  can be, for example, 3 micrometers, and the thickness of the second copper foil layer  110   b  can be, for example, 12 micrometers. The thickness of the first copper foil layer  110   a  is substantially equal to the thickness of the third copper foil layer  110   c . In other words, the thickness of the third copper foil layer  110   c  can also be, for example, 3 micrometers. The thickness of the second copper foil layer  110   b  is substantially equal to the thickness of the fourth copper foil layer  110   d . In other words, the thickness of the fourth copper foil layer  110   d  can also be, for example, 12 micrometers. Moreover, the second copper foil layer  110   b  of the present embodiment can be used to support the first copper foil layer  110   a . Similarly, the fourth copper foil layer  110   d  can also be used to support the third copper foil layer  110   c . Therefore, in the present embodiment, it is not necessary to use the conventional metal as the supporting carrier and the manufacturing cost can be decreased. In addition, in the present embodiment, the adhesive gel  120  includes, for example, cyanoacrylate (usually referred as an instant glue) or polypropylene resin (i.e. PP gel). It should be noticed that, although the second copper foil layer  110   b  is bonded the fourth copper foil layer  110   d  through the adhesive gel  120  in the present embodiment, the second copper foil layer  110   b  can be also bonded the fourth copper foil layer  110   d  through the welding copper foil method in other embodiments not shown in the drawings. That is, in the other embodiments, the adhesive gel  120  is the welded copper foil. Thus, the aforementioned welding copper foil method for bonding the second copper foil layer  110   b  and the fourth copper foil layer  110   d  still within the scope of the present invention. 
     Thereafter, as shown in  FIG. 1B , a plurality of first through holes  132  extending from the first copper foil layer  110   a  to the third copper foil layer  110   c  are formed. That is, the first through holes  132  at least penetrate through the first copper foil layer  110   a , the second copper foil layer  110   b , the fourth copper foil layer  110   d  and the third copper foil layer  110   c . In the present embodiment, the method of forming the first through holes  132  includes mechanical drilling. 
     As shown in  FIG. 1C , a first dielectric layer  150   a  and a first conductive layer  142  disposed on the first dielectric layer  150   a  are compressed on the first copper foil layer  110   a , and, meanwhile, a second dielectric layer  150   b  and a second conductive layer  144  disposed on the second dielectric layer  150   b  are compressed on the third copper foil layer  110   c . In the present embodiment, the first dielectric layer  150   a  and the second dielectric layer  150   b  face to the first copper foil layer  110   a  and the third copper foil layer  110   c  respectively, and portions of the first dielectric layer  150   a  and the second dielectric layer  150   b  fill in the first through holes  132 . In addition, the material of the first conductive layer  142  and the second conductive layer  144  can be, for example, copper. 
     Particularly, in the present embodiment, a sum of the thickness of the first dielectric layer  150   a  and the thickness of the first conductive layer  142  is substantially larger than a sum of the thickness of the first copper foil layer  110   a  and the thickness of the second foil layer  110   b . Further, the thickness of the first dielectric layer  150   a  can be, for example, 40 micrometers, and the thickness of the first conductive layer  142  can be, for example, 18 micrometers. Similarly, a sum of the thickness of the second dielectric layer  150   b  and the thickness of the second conductive layer  144  is substantially larger than a sum of the thickness of the third copper foil layer  110   c  and the thickness of the fourth copper foil layer  110   d . Further, the thickness of the second dielectric layer  150   b  is substantially equal to the thickness of the first dielectric layer  150   a  so that the thickness of the second dielectric layer  150   b  can be, for example, 40 micrometers. Also, the thickness of the second conductive layer  144  is substantially equal to the thickness of the first conductive layer  142  so that the thickness of the second conductive layer  144  can be, for example, 18 micrometers. 
     Furthermore, as shown in  FIG. 1D , a plurality of second through holes  134  extending from the first conductive layer  142  to the second conductive layer  144  are formed. The second through holes  134  at least penetrate through the first conductive layer  142 , the first dielectric layer  150   a , the first copper foil layer  110   a , the second copper foil layer  110   b , the fourth copper foil layer  110   c , the third copper foil layer  110   c , the second dielectric layer  150   b  and the second conductive layer  144 . Moreover, the second through holes  134  can be used to assist the removal of the adhesive gel  120  in later process step (i.e. the removal of the bonding region of the second copper foil layer  110   b  and the fourth copper foil layer  110   d ). Usually, the first conductive layer  142  and the second conductive layer  144  have several metal patterns (not shown) thereon, and the metal patterns are used as the positioning and aligning standard points in the manufacturing process. That is, the metal patterns on the first conductive layer  142  and the second conductive layer  144  can be used as the positioning and aligning standards of the first copper foil layer  110   a  and the third copper foil layer  110   c . Further, the metal patterns on the first conductive layer  142  and the second conductive layer  144  can also used as the positioning and aligning standards of the later formed fifth copper foil layer  110   e  (as shown in  FIG. 1G ). 
     Next, as shown in  FIG. 1E , the first conductive layer  142  and the second conductive layer  144  are respectively patterned, so as to form a first circuit layer  142   a  and a second circuit layer  144   a . The method for patterning the first conductive layer  142  and the second conductive layer  144  includes a photolithography and etching process. Particularly, the first conductive layer  142  and the second conductive layer  144  of the present embodiment are compressed on the first dielectric layer  150   a  and the second dielectric layer  150   b  respectively by the compressing process and are transformed in the first circuit layer  142   a  and the second circuit layer  144   a  respectively by the patterning process. Therefore, by comparing with the conventional technique that the circuit layers are formed by the copper plating method, the first circuit layer  142   a  and the second circuit layer  144   a  of the present embodiment have relatively better copper thickness uniformities. 
     Then, as shown in  FIG. 1F , the adhesive gel  120  is removed to form a first circuit structure  160   a  and a second circuit structure  160   b  which are separated from each other. In the present embodiment, the second through holes  134  can be used to assist the removal of the adhesive gel  120 . That is, because of the formation of the second through holes  134 , the adhesion of the adhesive gel  120  between the second copper foil layer  110   b  and the fourth copper foil layer  110   d  is damaged. Thus, it is easy to remove the adhesive gel  120 . Moreover, a method for removing the adhesive gel can be, for example, a mechanical drilling or a milling machine process. It should be noticed that, in the present embodiment, since the adhesive gel  120  only partially located between the second copper foil layer  110   b  and the fourth copper foil layer  110   d , the step of the present embodiment for removing the adhesive gel  120  is more simple and easy by comparing with the conventional technique for removing the mass of the gel between the circuit layer and the metal. Thus, the manufacturing yield can be increased. 
     In the present embodiment, the first circuit structure  160   a  and the second circuit structure  160   b  formed after the adhesive gel  120  is removed are the symmetrical structures. Further, the first circuit structure  160   a  comprises the first circuit layer  142   a , the first dielectric layer  150   a , the first copper foil layer  110   a  and the second copper foil layer  110   b  which are stacked sequentially. The second circuit structure  160   b  comprises the second circuit layer  144   a , the second dielectric layer  150   b , the third copper foil layer  110   c  and the fourth copper foil layer  110   d  which are stacked sequentially. To simplify the explanation, the first circuit structure  160   a  is used as an example in the following description of the formation of the package carrier. 
     As shown in  FIG. 1G , the second copper foil layer  110   b  is removed, and a third dielectric layer  150   c  and a fifth copper foil layer  110   e  on the third dielectric layer  150   c  are compressed on the first circuit layer  142   a . In the present embodiment, the method for removing the second copper foil layer  110   b  can be, for example, a lift-off process. That is, by using the lift-off process, the second copper foil layer  110   b  is lifted off the first copper foil layer  110   a . Moreover, since the third dielectric layer  150   c  and the fifth copper foil layer  110   e  are compressed on the first circuit layer  142   a , the first circuit layer  142   a  becomes an inner circuit layer. In other words, the first circuit layer  142   a  is a circuit layer buried between the third dielectric layer  150   c  and the first dielectric layer  150   a . Moreover, the metal patterns (not shown) on the first circuit layer  142   a  (which is formed by patterning the first conductive layer  142 ) are used as the standards in the step for compressing the fifth copper foil layer  110   e  on the first circuit layer  142   a  so that the alignment precision between the first copper foil layer  110   a , the first circuit layer  142   a  and the fifth copper foil layer  110   e  can be ensured. 
     Usually, the thickness of the fifth copper foil layer  110   e  is relatively small and can be, for example, 3 micrometers. Hence, when the compressing process is applied on the fifth copper foil layer  110   e , a thick copper foil layer (not shown) with a thickness about 12 micrometers is usually disposed on the fifth copper foil layer  110   e . Thus, the fifth copper foil layer  110   e  can be prevented from being bent after the compressing process. Therefore, the surface flatness of the fifth copper foil layer  110   e  after the compressing process can be well maintained. Thereafter, after the compressing process, the thick copper foil layer is lifted off to leave the thin fifth copper foil layer  110   e  for the later performed processes. 
     In other words, in the present embodiment, the third dielectric layer  150   c  and the fifth copper foil layer  110   e  disposed on the third dielectric layer  150   c  are compressed on the first circuit layer  142   a  after the adhesive gel  120  is removed. However, the present invention is not limited to the step order that the third rein layer  150   c  and the fifth copper foil layer  110   e  are compressed on the first circuit layer  142   a  after the adhesive gel  120  is removed. In other embodiments, the third dielectric layer  150   c  and the fifth copper foil layer  110   e  disposed on the third dielectric layer  150   c  can be compressed on the first circuit layer  142   a  before the adhesive gel  120  is removed. 
     More specifically, as shown in  FIG. 2A , the third dielectric layer  150   c  and the fifth copper foil layer  110   e  on the third dielectric layer  150   c  are compressed on the first circuit layer  142   a , and, meanwhile, a fourth dielectric layer  150   d  and a sixth copper foil layer  110   f  on the fourth dielectric layer  150   d  are compressed on the second circuit layer  144   a . Then, as shown in  FIG. 2B , the adhesive gel  120 , the second copper foil layer  110   b  and the fourth copper foil layer  110   d  are removed to form a third carrier unit  200   c  and a fourth carrier unit  200   d  which are separated from each other. Moreover, the third carrier unit  200   c  and the fourth carrier unit  200   d  formed by removing the adhesive gel  120 , the second copper foil layer  110   b  and the fourth copper foil layer  110   d  are the symmetrical structures. The third carrier unit  200   c  comprises the fifth copper foil layer  110   e , the third dielectric layer  150   c , the first circuit layer  142   a , the first dielectric layer  150   a  and the first copper foil layer  110   a  which are stacked sequentially. Similarly, the fourth carrier unit  200   d  comprises the sixth copper foil layer  110   f , the fourth dielectric layer  150   d , the second circuit layer  144   a , the second dielectric layer  150   b  and the third copper foil layer  110   c  which are stacked sequentially. In other words, the order of the steps for compressing the dielectric layer and the copper foil layer on the dielectric layer on the circuit layer and removing the adhesive gel  120  can be selectively adjusted according to the process requirement. Hence, the embodiment shown in  FIGS. 1F through 1G  is only an exemplary of the present invention and the present invention is not limited to this embodiment. 
     Thus, the manufacture of the first carrier unit  200   a  is completed. The first carrier unit  200   a  comprises the fifth copper foil layer  110   e , the third dielectric layer  150   c , the first circuit layer  142   a , the first dielectric layer  150   a  and the first copper foil layer  110   a  which are stacked sequentially. 
     Further, as shown in  FIG. 1H , a mechanical drilling is performed on the fifth copper foil layer  110   e  and the first copper foil layer  110   a  so as to form a plurality of first blind via  212  extending from the fifth copper foil layer  110   e  to the first circuit layer  142   a  and a plurality of second blind vias  214  extending from the first copper foil layer  110   a  to the first circuit layer  142   a . The first blind vias  212  and the second blind vias  214  expose a portion of the first circuit layer  142   a . In the present embodiment, the mechanical drilling can be, for example, a laser drilling. That is, the first blind vias  212  and the second blind vias  214  are formed by using the laser drilling. 
     As shown in  FIG. 1I , a chemical copper layer  220  is formed in the first blind vias  212  and the second blind vias  214 , wherein the chemical copper layer  220  connects the fifth copper foil layer  110   e  and the first circuit layer  142   a  and connects the first copper foil layer  110   a  and the first circuit layer  142   a . Specifically, in the present embodiment, the chemical copper layer  220  covers the fifth copper foil layer  110   e , the first blind vias  212 , the first copper foil layer  110   a  and the second blind vias  214 . Further, the fifth copper foil layer  110   e  is electrically connected to the first circuit layer  142   a  through the chemical copper layer  220 , and the first copper foil layer  110   a  is electrically connected to the first circuit layer  142   a  through the chemical copper layer  220 . Moreover, the method for forming the chemical copper layer  220  can be, for example, an electroless plating process. 
     As shown in  FIG. 1J , a first patterned dry film photoresist layer  232  is formed on the fifth copper foil layer  110   e , and a second patterned dry film photoresist layer  234  is formed on the first copper foil layer  110   a . The first pattern dry film photoresist layer  232  at least exposes the first blind vias  212  and the second patterned dry film photoresist layer  234  at least exposes the second blind vias  214 . Specifically, in the present embodiment, the first patterned dry film photoresist layer  232  exposes the chemical copper layer  220  in the first blind vias  212  and exposes a portion of the chemical copper layer  220  over the fifth copper foil layer  110   e . The second patterned dry film photoresist layer  234  exposes the chemical copper layer  220  in the second blind vias  214  and exposes a portion of the chemical copper layer  220  over the first copper foil layer  110   a.    
     As shown in  FIG. 1K , an copper plating copper layer  240  is formed at least in the first blind vias  212  and the second blind vias  214 , wherein the copper plating copper layer  240  fills up the first blind vias  212  and the second blind vias  214  and covers a portion of the chemical copper layer  220 . In the present embodiment, the copper plating copper layer  240  is formed within the first blind vias  212 , the second blind vias  214  and on a portion of the chemical copper layer  220  exposed by the first patterned dry film photoresist layer  232  and the second patterned dry film photoresist layer  234  by using a via filling plating process with the first patterned dry film photoresist layer  232  and the second patterned dry film photoresist layer  234  as the masks. 
     As shown in  FIG. 1L , the first patterned dry film photoresist layer  232 , and a portion of the chemical copper layer  220  and the fifth copper foil layer  110   e  under the first patterned dry film photoresist layer  232  are removed. Also, the second patterned dry film photoresist layer  234 , and a portion of the chemical copper layer  220  and the first copper foil layer  110   a  under the second patterned dry film photoresist layer  234  are removed. Therefore, the third dielectric layer  150   c  and a portion of the first dielectric layer  150   a  are exposed, and a first conductive blind via structure  212   a  is formed in each of the first bind holes  212  and a second conductive blind via structure  214   a  is formed in each of the second bind holes  214 . In the present embodiment, the method for removing the first patterned dry film photoresist layer  232 , and a portion of the chemical copper layer  220  and the fifth copper foil layer  110   e  under the first patterned dry film photoresist layer  232 , and the second patterned dry film photoresist layer  234 , and a portion of the chemical copper layer  220  and the first copper foil layer  110   a  under the second patterned dry film photoresist layer  234  can be, for example, an etching process. Thus, the first conductive blind via structures  212   a  and the second conductive blind via structures  214   a , both of which are electrically connected to the first circuit layer  142   a , are formed. 
     As shown in  FIG. 1M , a first protecting layer  252  is formed on the third dielectric layer  150   c  and a second protecting layer  254  is formed on the first dielectric layer  150   a . In the present embodiment, the first protecting layer  252  covers the third dielectric layer  150   c  and the first conductive blind via structures  212   a  exposed by the third dielectric layer  150   c  so that the integrity of the pattern of the first conductive blind via structures  212   a  can be well protected. Similarly, the second protecting layer  254  covers the first dielectric layer  150   a  and the second conductive blind via structures  214   a  exposed by the first dielectric layer  150   a  so that the integrity of the pattern of the second conductive blind via structures  214   a  can be well protected. Moreover, the method for forming the first protecting layer  252  and the second protecting layer  254  can be, for example, a screen printing. The material of the first protecting layer  252  and the second protecting layer  254  can be, for example, ink. 
     As shown in  FIG. 1N , a polishing process is performed to remove a portion of the first protecting layer  252  until the surface of the first conductive blind via structures  212   a  are exposed and to remove a portion of the second protecting layer  254  until the surface of the second conductive blind via structures  214   a  are exposed. Meanwhile, the surface of the first protecting layer  252  is substantially aligned with the surfaces of the first conductive blind via structures  212   a , and the surface of the second protecting layer  254  is aligned with the surfaces of the second conductive blind via structures  214   a.    
     Furthermore, as shown in  FIG. 1O , the rest portion of the first protecting layer  252  and the rest portion of the second protecting layer  254  are removed to expose a portion of the third dielectric layer  150   c , the first conductive blind vias  212   a  exposed by the third dielectric layer  150   c , a portion of the first dielectric layer  150   a  and the second conductive blind vias  214   a  exposed by the first dielectric layer  150   a . In the present embodiment, the purpose of the process comprises, in sequence, forming the first protecting layer  252  and the second protecting layer  254 , performing the polishing process and removing the first protecting layer  252  and the second protecting layer  254  is to improve the surface flatness of the surfaces of the first conductive blind via structures  212   a  and the second conductive blind via structures  214   a.    
     As shown in  FIG. 1P , a first solder mask layer  262  is formed on the third dielectric layer  150   c  and a second solder mask layer  264  is formed on the first dielectric layer  150   a . In the present embodiment, the first solder mask layer  262  has a plurality of first openings  262   a , wherein a portion of the first conductive blind via structures  212   a  exposed by the first openings  262   a  are used as the bonding pads. The second solder mask layer  264  has a plurality of second openings  264   a , wherein a portion of the second conductive blind via structures  214   a  exposed by the second openings  264   a  are used as the bonding pads. Herein, the fabricating of the package carrier  100  is completed. 
     The first conductive blind via structures  212   a  exposed by the first openings  262   a  of the first solder mask layer  262  are used as the bonding pads, and the second conductive blind via structures  214   a  exposed by the second openings  264   a  of the second solder mask layer  264  are used as the bonding pads. Thus, after the chip (not shown) is electrically connected to the bonding pads by the wire bonding or flip-chip process and the chip is encapsulated in a compound (not shown), the chip package process is completed. That is, the package carrier  100  of the present embodiment is suitable to be a chip package carrier. 
     In other words, in the present embodiment, because it is not necessary to use the metal for supporting the first copper foil layer  110   a  and the second copper foil layer  110   c , the method for manufacturing the package carrier is capable of effectively decreasing the manufacturing cost by comparing with the conventional technique. In addition, in the present embodiment, the first circuit layer  142   a  and the second circuit layer  144   a  are formed by compressing the first conductive layer  142  and the second conductive layer  144 , and then patterning the first conductive layer  142  and the second conductive layer  144 . By comparing with the conventional technique that the circuit layers are formed by the copper plating method, the first circuit layer  142   a  and the second circuit layer  144   a  of the present embodiment have relatively better copper thickness uniformities. Further, in the present embodiment, by using the first circuit layer  142   a  (which is made from the first conductive layer  142 ) as the positioning and aligning standard of the first copper foil layer  110   a  and the fifth copper foil layer  110   e . Hence, the alignment precision of the package carrier  100  can be effectively increased so that the manufacturing yield and the reliability of the package carrier  100  are improved. 
     According to the above description, in the present invention, the copper foil layers are bonded each other by using the adhesive gel. Comparing with the conventional technique in which the metal is used as the carrier for supporting the circuit layer, in the present invention, the method for forming the package carrier is capable of effectively decreasing the cost for manufacturing the package carrier. Also, in the present invention, it is not necessary to use mass of gel to fix the circuit layer on the metal as taught by the conventional technique so that the method for forming the package carrier may not confront the difficulty in removing the mass of gel layer. Therefore, the manufacturing process of the present invention is more simple and easy. Moreover, the conductive layers are laminated by the compressing process, and then the circuit layers are formed by the patterning the conductive layers. Therefore, by comparing with the conventional technique that the circuit layers are formed by the copper plating method, the circuit layers have relatively better copper thickness uniformities. Furthermore, in the present invention, by using one circuit layer as the positioning standard, the alignment precision between the copper foil layers and the circuit layers can be effectively increased. In general, the package carrier formation method of the present invention is capable of simplifying the manufacturing steps, decreasing the manufacturing cost, increasing the manufacturing yield and further increasing the product reliability. 
     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.