Abstract:
A method of manufacturing a passive component module, comprising the steps of: providing a carrier with alignment marks; bonding passive components to the carrier based on the alignment marks, wherein each passive component has interconnection pads; forming a molding material over the carrier for molding the passive components; separating the molding material with the passive components from the carrier; exposing all interconnection pads of each passive component; and building electrical interconnections between the passive components so that the passive component module is obtained.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates to manufacture of an electronic device, and more particularly relates to a method of manufacturing a passive component module. 
       BACKGROUND OF THE INVENTION 
       [0002]    Passive component is widely applied in various consumer electronics incorporating a print circuit board. While consumer electronics continues in its trend of shrinkage, more and more passive components are integrated in a print circuit board. 
         [0003]    A highly integrated print circuit board with numerous passive components is usually manufactured by embedding one or more passive components in each cavity of a substrate. However, creating each cavity in a substrate for embedding each passive component takes time, and keeping sufficient distance between neighboring cavities can hinder further shrinkage of the print circuit board. On the other hand, arranging several passive components in a single cavity easily results in shift of components that may cause interconnection opens. Furthermore, passive components with different dimensions also increase difficulty and complexity in embedding process thereof. 
         [0004]    Accordingly, a method capable of solving the aforementioned drawbacks is desirable. 
       SUMMARY OF THE INVENTION 
       [0005]    In view of the aforementioned drawbacks in prior art, one embodiment of the invention provides a method of manufacturing a passive component module. The method comprises the steps of: providing a carrier with alignment marks; bonding passive components to the carrier based on the alignment marks, wherein each passive component has interconnection pads; forming a molding material over the carrier for molding the passive components; separating the molding material with the passive components from the carrier; exposing all interconnection pads of each passive component; and building electrical interconnections between the passive components so that the passive component module is obtained. 
         [0006]    In another embodiment of the invention, a method of manufacturing a print circuit board is disclosed. The method comprises the steps of embedding the passive component module formed in accordance with the method of claim  1  into a substrate; embedding at least an active component into the substrate; and building electrical interconnections between the passive component module and the active component so that the print circuit board is obtained. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  to  FIG. 5  illustrate a method of manufacturing a passive component module. 
           [0008]      FIG. 6  is a plan view illustrating a passive component module of  FIG. 5 . 
           [0009]      FIG. 7A  is a plan view illustrating a passive component module of  FIG. 5  that is further processed with an RDL process. 
           [0010]      FIG. 7B  is a plan view illustrating a portion (or piece) of a print circuit board with the passive component module of  FIG. 7A  embedded therein. 
           [0011]      FIG. 8A  is a plan view illustrating a portion (or piece)  48  of a print circuit board with a passive component module of  FIG. 5 . 
           [0012]      FIG. 8B  is a plan view illustrating a piece of a print circuit board as shown in  FIG. 8A  that is processed without further RDL process. 
           [0013]      FIG. 9  is a plan view illustrating a print circuit board consisted of a number of pieces as shown in  FIG. 7B  and  FIG. 8B . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0014]    The present invention may best be understood by reference to the following description in conjunction with the accompanying drawings, in which similar reference numbers represent similar elements. Any devices, components, materials, and steps described in the embodiments are only for illustration and not intended to limit the scope of the present invention. 
         [0015]      FIG. 1  to  FIG. 5  illustrate a method of manufacturing a passive component module. 
         [0016]    Referring to  FIG. 1 , a carrier  10  with alignment marks (not shown) thereon is provided and an adhesive layer  12  is formed overlying the carrier  10 . Thereafter, a number of passive components  14 ,  20  and  26  are bonded to the carrier  10  using a die bonder or chip shooter. The alignment marks facilitate the bonding process by increasing precision. The adhesive layer  12  serves as a sacrificial layer for temporarily attaching the passive components  14 ,  20  and  26  to the carrier  10 . Noted that the passive components  14 ,  20  and  26  respectively have interconnection pads at two ends thereof. For example, the passive component  14  has interconnection pads  16  and  18 ; the passive component  20  has interconnection pads  22  and  24 ; and the passive component  26  has interconnection pads  28  and  30 . Also noted that the passive components  14 ,  20  and  26  have different dimensions and result in step heights therebetween accordingly. The carrier  10  may be composed of glass, fiber resin or ceramic. 
         [0017]    Referring to  FIG. 2 , a molding material  32  is formed subsequently over the adhesive layer  12  for molding the passive components  14 ,  20  and  26 . The molding material  32  can be suitable material such as epoxy resin, and further undergoes well-known treatments after formation. In another embodiment, the molding material  32  may be directly formed over the carrier  10  for molding the passive components  14 ,  20  and  26  because the adhesive layer  12  is optional. 
         [0018]    Referring to  FIG. 3 , the next step is performed by separating the molding material  32  with the passive components  14 ,  20  and  26  from the carrier  10 . In this embodiment, removal of the entire adhesive layer  12  is further performed using well-known techniques. 
         [0019]    Referring to  FIG. 4 , the molding material  32  with the passive components  14 ,  20  and  26  is reversed upward for undergoing a subsequent polishing or grinding process. In another embodiment, the molding material  32  with the passive components  14 ,  20  and  26  may undergo a subsequent polishing or grinding process without the step of reversing. 
         [0020]    Referring to  FIG. 5 , a polishing or grinding process is performed until obtaining the processed interconnection pads of each passive component, e.g. interconnection pads  16   a,    18   a,    22   a,    24   a,    28   a  and  30   a,  utilizing well-known techniques. Noted that all exposed surfaces of the processed interconnection pads  16   a,    18   a,    22   a,    24   a,    28   a  and  30   a  are coplanar. So far, the passive component module of this embodiment is initially obtained. In another embodiment, one or more of the interconnection pads  16 ,  18 ,  22 ,  24 ,  28  and  30  might be completely embedded into the molding material  32 , so that at least a portion of the molding material  32  needs to be removed until exposing all of the aforementioned interconnection pads. 
         [0021]      FIG. 6  is a plan view illustrating a passive component module of  FIG. 5 . Referring to  FIG. 6 , all exposed surfaces of the processed interconnection pads  16   a,    18   a,    22   a,    24   a,    28   a  and  30   a  are going to undergo subsequent processes, e.g. wafer level redistribution (abbreviated as RDL), for creation of electrical connection as shown in  FIG. 7 . In another embodiment, the passive component module  32  of  FIG. 5  can be embedded together with other active or passive components into a PCB substrate prior to being treated with a conventional PCB process for formation of interconnection. The just aforementioned RDL and PCB processes for making electrical connection (or interconnection) will be described later, respectively with reference to  FIGS. 7A to 7B  and  FIGS. 8A to 8B . 
         [0022]      FIG. 7A  is a plan view illustrating a passive component module of  FIG. 5  that is further processed with an RDL process. Referring to  FIG. 7A , an RDL process is subsequently performed to further make electrical interconnections  34 ,  36  and  38  between exposed interconnection pads  16   a,    18   a,    22   a,    24   a,    28   a  and  30   a.  That is, the electrical interconnection  34  makes electrical contact between the passive components  20  and  26 ; the electrical interconnection  36  makes electrical contact between the passive components  14  and  20 ; and the electrical interconnection  38  makes electrical contact between the passive components  14  and  26 . So far, the passive components  14 ,  20  and  26  in this passive component module of this embodiment are electrically coupled to each other. 
         [0023]      FIG. 7B  is a plan view illustrating a portion (or piece)  48  of a print circuit board with the passive component module of  FIG. 7A  embedded therein. Referring to  FIG. 7B , the passive component module of  FIG. 7A  is further embedded into a print circuit board  100  (as shown in  FIG. 9 ) and electrically connected to active and/or passive components  46   a  and  46   b  via interconnections  40 ,  42  and  44  by the known print circuit board manufacturing process. Noted that active and/or passive components  46   a  and  46   b  also have interconnection pads  52 ,  54 ,  56 ,  58 ,  60 ,  62  and  64  for electronic contact with other interconnection pads. For example, an electrical interconnection  50  makes electrical contact between the interconnection pads  62  and  64 ; the electrical interconnection  40  makes electrical contact between the interconnection pads  54  and  30   a;  the electrical interconnection  42  makes electrical contact between the interconnection pads  56  and  18   a;  and the electrical interconnection  44  makes electrical contact between the interconnection pads  58  and  16   a.    
         [0024]    Next, another embodiment employing a PCB processes for making electrical connection (or interconnection) will be described below accompanying  FIG. 8A  and  FIG. 8B . 
         [0025]      FIG. 8A  is a plan view illustrating a portion (or piece)  48  of a print circuit board with a passive component module of  FIG. 5 .  FIG. 8B  is a plan view illustrating a piece of a print circuit board as shown in  FIG. 8A  that is processed without further RDL process.  FIG. 8A  shows that all of the passive/active component modules  32 ,  46   a  and  46   b  are embedded into a print circuit board  100  (as shown in  FIG. 9 ).  FIG. 8B  shows making electrical contact between the interconnection pads of the passive/active component modules  32 ,  46   a  and  46   b  subsequent to the embedding step of  FIG. 8A . 
         [0026]      FIG. 9  is a plan view illustrating a print circuit board consisted of a number of pieces as shown in  FIG. 7B  and  FIG. 8B . As shown in  FIG. 9 , the print circuit board  100  has a number of portion (or piece)  48  can be protected by suitable materials prior to a cutting process. Such materials can be Pd, Ni, Cu and Au. 
         [0027]    Although specific embodiments have been illustrated and described, it will be obvious to those skilled in the art that various modifications may be made without departing from what is intended to be limited solely by the appended claims.