Abstract:
A semiconductor device and a fabrication method of the same are proposed, in which at least one electronic component is firstly mounted on a first substrate, and then the first substrate is attached onto a semiconductor chip or a second substrate. Further, with the chip being deposited on the second substrate, electrical connection is established among the first substrate, the second substrate and the chip. This combined structure is subsequently subjected to molding, ball implantation and singulation processes, and thus completes the fabrication of the semiconductor device. Such a semiconductor device provides significant advantages, including prevention of the occurrence of wire short-circuiting, no need to alter the substrate design, no need to use a circuit pattern with fine pitches or an expensive substrate integrated with electronic components.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to semiconductor devices and fabrication methods of the same, and more particularly, to a semiconductor device incorporated with electronic components such as passive components, and a method for fabricating the semiconductor device.  
         BACKGROUND OF THE INVENTION  
         [0002]    Generally, in order to desirably improve performances and functionality, semiconductor devices are often made in association with electronic components such as passive components. For example, U.S. Pat. Nos. 5,264,730, 5,311,405, 5,811,880, 5,825,628 and 6,316,828 disclose the incorporation of passive components on substrates for use in BGA (ball grid array) semiconductor packages, which passive components are purposed in enhancing overall electrical functions of the semiconductor packages.  
           [0003]    Such a substrate with passive components being mounted thereon for use in a semiconductor device is illustrated in FIG. 9, wherein the passive components  40  such as resistors or capacitors are preferably disposed on a ground ring  13  and a power ring  12  of the substrate  10  at positions close to a chip  20  that is accommodated on the substrate  10 . In particular, the passive components  40  are most preferably positioned at four corners in proximity to the chip  20 , respectively.  
           [0004]    However, as the passive components  40  occupied certain layout area on the substrate  10 , pitches P between adjacent bond fingers  11  that are located between two passive components  40 , are necessarily reduced from conventional dimensions of 0.150 mm to fine pitches such as 0.125 mm. This thereby significantly increases the fabrication costs.  
           [0005]    Besides, the passive components  40  also adversely affect trace routability on the substrate  10 ; routing area and space for conductive traces (not shown) formed on the substrate  10  are both restricted by the arrangement of the passive components  40 . On the contrary, in concern of complying with trace routability of the substrate  10 , the passive components  40  must be arranged in a manner as not to interfere with the conductive traces formed on the substrate  10 ; this limits the number and positioning of the passive components  40  to be adopted in semiconductor devices.  
           [0006]    Moreover, in case of the passive components  40  being disposed at peripheral positions instead of the corners nearby the chip  20  according to practical requirements, bonding wires  30  are formed to extend from the chip  20  and across the passive components  40 , for electrically connecting bond pads  21  of the chip  20  to the corresponding bond fingers  1 I on the substrate  10 . However, as shown in FIG. 10, short circuit may easily occur as the bonding wires  30  come into contact with edges of the passive components  40 , which thereby degrades the wire bonding quality and product reliability. Although this short-circuiting problem can be solved by pre-encapsulating the passive components  40  with an insulating material before forming the bonding wires  30 , this pre-encapsulation process would undesirably increase complexity and costs in fabrication.  
           [0007]    In response to the above-mentioned drawbacks, U.S. Pat. No. 5,670,824 discloses a type of substrate integrally formed with passive components, which substrate can be disposed underneath a chip for carrying the chip thereon. However, since conventional passive components such as resistors or capacitors are not suitably applied to this integration type of substrate, forming the integration substrate requires particularly designed passive components, and significantly raises the fabrication costs. Such an expensive substrate is hard to be commercialized and widely used in semiconductor industry.  
           [0008]    Furthermore, Taiwan Patent Application No. 89121891 discloses a semiconductor structure illustrated in FIG. 11, in which a passive component  40  is directly mounted on and electrically connected to a chip  20  that is accommodated on a substrate  10 . However, this semiconductor structure is rather complexly made, which needs to pre-form a plurality of connection pads  22  on the chip  20  for subsequently attaching the passive component  40  thereto. These connection pads  22  are then subjected to under bumping metalization, so as to electrically connect the connection pads  22  to solder paste that is applied for adhering the passive component  40  onto the connection pads  22 . As a result, fabrication -of this semiconductor structure is considerably complicated and cost-ineffective to implement.  
           [0009]    Another embodiment of the semiconductor structure disclosed by the foregoing Taiwan patent, as shown in FIG. 12, involves the forming of conductive wires  42 ,  43  for electrically connecting the passive component  40  that is directly mounted on the chip  20  to a power ring  12  and a ground ring  13  on the substrate  10 . However, contact terminals (not shown) formed on the passive component  40  for wire bonding use are not satisfactorily surface-flat, making a conventional wire bonding machine not able to, operate at the contact terminals for forming the conductive wires  42 ,  43 . Moreover, if the contact terminals of the passive component  40  are not plated with gold, the wire bonding process cannot be implemented either. Therefore, since this semiconductor structure is hardly fabricated in large scale by using currently available equipment and processes, it is potentially low in demand in the market.  
           [0010]    In accordance with the foregoing described, the present invention provides a novel, advanced and practical semiconductor device and a fabrication method thereof, so as to overcome the multiple drawbacks recited above in the prior arts.  
         SUMMARY OF THE INVENTION  
         [0011]    A primary objective of the present invention is to provide a semiconductor device incorporated with electronic components such as passive components and a fabrication method of the semiconductor device, in which fine-pitch arrangement of bond fingers on a substrate needs not to be adopted.  
           [0012]    Another objective of the invention is to provide a semiconductor device incorporated with electronic components such as passive components and a fabrication method of the semiconductor device, in which trace routability of a substrate, and number and positioning of the electronic components are not particularly limited for use in the semiconductor device.  
           [0013]    Still another objective of the invention is to provide a semiconductor device incorporated with electronic components such as passive components and a fabrication method of the semiconductor device, which can prevent the occurrence of short circuit caused by bonding wires coming into contact with the electronic components.  
           [0014]    A further objective of the invention is to provide a semiconductor device incorporated with electronic components such as passive components and a fabrication method of the semiconductor device, in which an expensive substrate integrated with electronic components needs not to be used, thereby making fabrication costs significantly reduced.  
           [0015]    A further objective of the invention is to provide a semiconductor device incorporated with electronic components such as passive components and a fabrication method of the semiconductor device, in which no connection pads for mounting the electronic components thereon need to be formed on a chip, and thus no under bumping metalization for the connection pads is necessarily performed, so that fabrication processes and costs can be simplified and reduced, respectively.  
           [0016]    A further objective of the invention is to provide a semiconductor device incorporated with electronic components such as passive components and a fabrication method of the semiconductor device, in which a conventional wire bonding machine is suitably applied for forming bonding wires, and the semiconductor device can be fabricated in a batch manner by using currently available processes and equipment.  
           [0017]    In accordance with the above and other objectives, the present invention proposes a semiconductor device and a fabrication method of the same.  
           [0018]    The semiconductor device of the invention comprises:  
           [0019]    at least one electronic component having a first surface and a second surface;  
           [0020]    a first substrate having a first surface and a second surface, wherein the second surface of the electronic component is electrically connected to the first surface of the first substrate;  
           [0021]    a semiconductor chip having a first surface and a second surface;  
           [0022]    a second substrate having a first surface and a second surface, wherein the second surface of the semiconductor chip is attached to the first surface of the second substrate, which combined structure of the semiconductor chip and the second substrate accommodates the first substrate that is mounted with the electronic component thereon in a manner that, for example, the second surface of the first substrate is attached to the first surface of the semiconductor chip or to the first surface of the second substrate, or to other suitable positions;  
           [0023]    a plurality of bonding wires for establishing electrical connection among the first surface of the semiconductor chip, the first surface of the first substrate and the first surface of the second substrate;  
           [0024]    an encapsulant formed on the first surface of the second substrate, for encapsulating the electronic component, the first substrate, the semiconductor chip and the bonding wires; and  
           [0025]    a plurality of solder balls implanted on the second surface of the second substrate.  
           [0026]    The fabrication method of the foregoing semiconductor device of the invention comprises the steps of:  
           [0027]    preparing a first substrate, at least one electronic component, a semiconductor chip and a second substrate, each of which has a first surface and a second surface;  
           [0028]    electrically connecting the second surface of the electronic component to the first surface of the first substrate;  
           [0029]    attaching the second surface of the semiconductor chip to the first surface of the second substrate;  
           [0030]    disposing the first substrate mounted with the electronic component on combined structure of the semiconductor chip and the second substrate in a manner that, for example, the second surface of the first substrate is attached to the first surface of the semiconductor chip or to the first surface of the second substrate, or to other suitable positions;  
           [0031]    forming a plurality of bonding wires for establishing electrical connection among the first surface of the semiconductor chip, the first surface of the first substrate and the first surface of the second substrate;  
           [0032]    forming an encapsulant on the first surface of the second substrate, for encapsulating the electronic component, the first substrate, the semiconductor chip and the bonding wires; and  
           [0033]    implanting a plurality of solder balls on the second surface of the second substrate.  
           [0034]    The foregoing semiconductor device and its fabrication method of the invention can also be suitably applied to a leadframe-based semiconductor device, wherein the second surface of the first substrate mounted with the electronic component thereon is attached to the first surface of the semiconductor chip. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0035]    The present invention can be more fully understood by reading the following detailed description of the preferred embodiments, with reference made to the accompanying drawings, wherein:  
         [0036]    [0036]FIGS. 1A and 1B are respectively a front view and a top view of a first substrate used in the invention;  
         [0037]    [0037]FIGS. 2A and 2B are respectively a front view and a top view showing electronic components mounted on a first substrate of the invention;  
         [0038]    [0038]FIGS. 3A and 3B are respectively a front view and a top view showing a semiconductor chip mounted on a second substrate of the invention;  
         [0039]    [0039]FIGS. 4A and 4B are respectively a front view and a top view showing a first substrate mounted with electronic components and attached onto a semiconductor chip in accompany with the forming of bonding wires of the invention;  
         [0040]    [0040]FIG. 5 is a front view of a semiconductor device formed with an encapsulant and implanted with solder balls of the invention;  
         [0041]    [0041]FIGS. 6A and 6B are schematic diagrams showing other preferred embodiments for forming bonding wires of the invention;  
         [0042]    [0042]FIG. 7 is a schematic diagram showing another preferred embodiment of a semiconductor device of the invention;  
         [0043]    [0043]FIG. 8A is a structural top view showing a further preferred embodiment of a semiconductor structure of the invention prior to a molding process;  
         [0044]    [0044]FIG. 8B is a schematic diagram showing the semiconductor structure of FIG. 8A after molding and implanted with solder balls;  
         [0045]    [0045]FIG. 9 (PRIOR ART) is a schematic diagram showing a conventional substrate mounted with passive components for use in a semiconductor device;  
         [0046]    [0046]FIG. 10 (PRIOR ART) is a schematic diagram showing the occurrence of short circuit for a conventional substrate mounted with passive components for use in a semiconductor device;  
         [0047]    [0047]FIG. 11 (PRIOR ART) is a structural schematic diagram showing another conventional substrate mounted with passive components for use in a semiconductor device; and  
         [0048]    [0048]FIG. 12 (PRIOR ART) is a structural schematic diagram showing a further conventional substrate mounted with passive components for use in a semiconductor device. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0049]    As shown in FIG. 5, a semiconductor device of the present invention comprises at least one electronic component  41 , a first substrate  50 , a semiconductor chip  20 , a second substrate  10 , plural sets of bonding wires  30 ,  31 ,  32 ,  33 ,  34 , an encapsulant  60 , and a plurality of solder balls  70 .  
         [0050]    The electronic component  41  has a first surface  44  and an opposing second surface  45 , and can be a passive component such as resistor and capacitor, or other suitable types of electronic components. The second surface  45  of the electronic component  41  is bonded to a first surface  56  of the first substrate  50  by using conventional technique such as reflow soldering, and electrically connected to a power bond pad  54  and a ground bond pad  55  formed on the first surface  56  of the first substrate  50 .  
         [0051]    The semiconductor chip  20  also has a first surface  22  and an opposing second surface  23 , which second surface  23  is attached to a first surface  14  of the second substrate  10  by conventional means such as adhesion. The first substrate  50  with the electronic component  41  being carried thereon can be optionally mounted on the semiconductor chip  20  in a manner that, a second surface  57  of the first substrate  50  is adhered onto the first surface  22  of the semiconductor chip  20 .  
         [0052]    The plural sets of bonding wires  30 ,  31 ,  32 ,  33 ,  34  such as gold wires are respectively formed to establish electrical connection among the first surface  22  of the semiconductor chip  20 , the first surface  56  of the first substrate  50 , and the first surface  14  of the second substrate  10 . In particular, as shown in FIGS. 4B and 5, the bonding wires  30  electrically connect signal pads of bond pads  21  formed on the first surface  22  of the semiconductor chip  20 , to corresponding signal fingers  11  that are formed on the first surface  14  of the second substrate  10 . The bonding wires  31  electrically connect power pads of the bond pads  21  on the first surface  22  of the semiconductor chip  20 , to a first set of power fingers  52  that are formed on the first surface  56  of the first substrate  50  and electrically coupled to the power bond pads  54 . And, the bonding wires  32  electrically connect a second set of power fingers  52  formed on the first surface  56  of the first substrate  50 , to a power ring  12  formed on the first surface  14  of the second substrate  10 , wherein the second set of power fingers  52  are in parallel connection with the first set of power fingers  52 .  
         [0053]    Similarly, the bonding wires  33  electrically connect ground pads of the bond pads  21  on the first surface  22  of the semiconductor chip  20 , to a first set of ground fingers  53  that are formed on the first surface  56  of the first substrate  50  and electrically coupled to the ground bond pads  55 . The bonding wires  34  electrically connect a second set of ground fingers  53  formed on the first surface  56  of the first substrate  50 , to a ground ring  13  formed on the first surface  14  of the second substrate  10 , wherein the second set of ground fingers  53  are in parallel connection with the first set of ground fingers  53 .  
         [0054]    The encapsulant  60  for protection purpose is formed on the first surface  14  of the second substrate  10 , and encapsulates the electronic component  41 , the first substrate  50 , the semiconductor chip  20  and the bonding wires  30 ,  31 ,  32 ,  33 ,  34 . The plurality of solder balls  70  are implanted on a second surface  15  of the second substrate  10 , and allow the semiconductor device of the invention to be electrically connected to external devices (not shown).  
         [0055]    Alternatively, as shown in FIGS. 8A and 8B, the above first substrate  50  with the electronic component  41  being carried thereon can be mounted on the first surface  14 ′ of the second substrate  10 ′; this significantly reduces overall height of the semiconductor device of the invention. In this embodiment, plural sets of bonding wires  30 ,  35 ,  36  are respectively formed to establish electrical connection among the first surface  22  of the semiconductor chip  20 , the first surface  14 ′ of the second substrate  10 ′, and the first surface  56  of the first substrate  50 , whereby the semiconductor chip  20 , the second substrate  10 ′ and the first substrate  50  (the electronic component  41 ) can be electrically coupled to each other.  
         [0056]    In addition, wire connection among the first substrate  50 , the semiconductor chip  20  and the second substrate  10  can be alternatively made in a manner shown in FIG. 6A, wherein the bonding wires  32 ,  34  of FIG. 5 are replaced by bonding wires  32 ′,  34 ′, respectively. As shown in the drawing, the bonding wires  32 ′ electrically connect the power pads of the bond pads  21  formed on the first surface  22  of the semiconductor chip  20 , to the power ring  12  formed on the first surface  14  of the second substrate  10 . And, the bonding wires  34 ′ electrically connect the ground pads of the bond pads  21  on the first surface  22  of the semiconductor chip  20 , to the ground ring  13  on the first surface  14  of the second substrate  10 .  
         [0057]    Moreover, a further embodiment of wire connection established among the first substrate  50 , the semiconductor chip  20  and the second substrate  10  is illustrated in FIG. 6B, which is accomplished by replacing the bonding wires  31 ,  33  of FIG. 5 with the bonding wires  32 ′,  34 ′ shown in FIG. 6A, so as to achieve desirable electrical connection for internal elements in the semiconductor device of the invention.  
         [0058]    It should be understood that, the foregoing embodiments illustrated in FIGS. 8A and 8B can also alternatively adopt the arrangement of wire connection in FIG. 6A or  6 B. Further description thereof is not to be detailed herein.  
         [0059]    Furthermore, the invention is also suitably applied to a leadframe-based semiconductor device, as shown in FIG. 7, in which the first substrate  50  accommodating the electronic component  41  is positioned in a manner as to attach its second surface  57  to the first surface  22  of the semiconductor chip  20 , and the second surface  23  of the semiconductor chip  20  is adhered onto a die pad  100 . The plural sets of bonding wires  30 ,  31 ,  32 ,  33 ,  34  are respectively formed to establish electrical connection among the first surface  22  of the semiconductor chip  20 , the first surface  56  of the first substrate  50 , and inner portions of a plurality of leads  70 ′ formed around the semiconductor chip  20 . A protective encapsulant  60 ′ encapsulates the electronic component  41 , the first substrate  50 , the semiconductor chip  20 , the die pad  100 , the bonding wires  30 ,  31 ,  32 ,  33 ,  34 , and the inner portions of the plurality of leads  70 ′. Alternatively, wire connection in this embodiment can be adapted in a manner illustrated in FIG. 6A or  6 B, which also allows desirable electrical connection to be equivalently achieved.  
         [0060]    Referring to FIG. 5, a fabrication method of the semiconductor device of the invention comprises the following steps.  
         [0061]    First, a first substrate  50  having a first surface  56  and an opposing second surface  57  is prepared, as shown in FIGS. 1A and 1B. The first surface  56  of the first substrate  50  is formed thereon with a plurality of power fingers  52 , ground fingers  53 , power bond pads  54  and ground bond pads  55 , wherein the power fingers  52  and the ground fingers  53  are respectively paired up in parallel connection, and electrically coupled to the power bond pads  54  and the ground bond pads  55 .  
         [0062]    Next, a plurality of electronic components  41  have second surfaces  45  thereof being bonded onto the first surface  56  of the first substrate  50  by using conventional technique such as reflow soldering, as shown in FIGS. 2A and 2B, so as to allow the electronic components  41  to be electrically connected to the power bond pads  54  and the ground bond pads  55  formed on the first substrate  50 . The electronic components  41  can be, for example, passive components such as resistors or capacitors.  
         [0063]    Then, referring to FIGS. 3A and 3B, a semiconductor chip  20  is mounted on a second substrate  10  in a manner that, a second surface  23  of the semiconductor chip  20  is attached to a first surface  14  of the second substrate  10  by conventional means such as adhesion.  
         [0064]    Referring further to FIGS. 4A and 4B, the first substrate  50  carrying the electronic components  41  thereon is mounted on the semiconductor chip  20  by adhering the second surface  57  of the first substrate  50  to a first surface  22  of the semiconductor chip  20 . Subsequently, plural sets of electrically-conductive bonding wires  30 ,  31 ,  32 ,  33 ,  34  such as gold wires are respectively formed to establish electrical connection among the first surface  22  of the semiconductor chip  20 , the first surface  56  of the first substrate  50 , and the first surface  14  of the second substrate  10 . Since detailed wire connection for these bonding wires  30 ,  31 ,  32 ,  33 ,  34  is previously described in the embodiments of the semiconductor device of the invention, no further depiction thereof is to be recited herein.  
         [0065]    Thereafter, referring to FIG. 5, a molding process is performed, in which a protective encapsulant  60  is formed on the first surface  14  of the second substrate  10 , for encapsulating the electronic components  41 , the first substrate  50 , the semiconductor chip  20 , and the plurality of bonding wires  30 ,  31 ,  32 ,  33 ,  34 . Finally, a plurality of solder balls  70  are implanted on a second surface  15  of the second substrate  10 , allowing the fabricated semiconductor device to be electrically connected to external devices (not shown) by virtue of the solder balls  70 .  
         [0066]    The semiconductor device fabricated by the above method can alternatively adopt the arrangement of wire connection previously illustrated in FIG. 6A or  6 B, which also allows desirable electrical connection to be equivalently accomplished.  
         [0067]    Besides, as described above for FIG. 8B, the first substrate  50  with the electronic components  41  being carried thereon can be alternatively mounted on the first surface  14 ′ of the second substrate  10 ′, thereby making the semiconductor device significantly reduced in overall height thereof.  
         [0068]    Moreover, the foregoing fabrication method of the invention is also suitably applied for manufacturing a leadframe-based semiconductor device illustrated in FIG. 7, in which two additional steps are required for the fabrication of the leadframe-based semiconductor device, including the mounting of the first substrate  50  carrying the electronic components  41  on the semiconductor chip  20 , and the forming of extra bonding wires from the first surface  56  of the first substrate  50 . Therefore, no further description thereof is to be detailed herein.  
         [0069]    In addition, the foregoing fabrication method of the invention is further suitably applied to batch production of semiconductor devices with the use of matrix-arranged substrates. First, a plurality of matrix-arranged first substrates  50  are made in advance, and then a plurality of electronic components  41  are bonded to the corresponding first substrates  50 , respectively. A singulation process is performed afterwards to form individual first substrates  50  with the electronic components  41  being carried thereon. At the same time, a plurality of matrix-arranged second substrates  10  can be similarly prepared, each of which second substrates  10  is mounted with the semiconductor chip  20  and the above singulated first substrate  50 . The matrix-arranged second substrates  10  are then subjected to wire bonding, molding, ball implantation and singulation processes to form individually singulated semiconductor devices of the invention.  
         [0070]    In conclusion, the foregoing semiconductor device and its fabrication method of the invention provide significant benefits. For example, improvements in performances and functionality of the semiconductor device can be achieved by incorporating electronic components such as passive components of resistors or capacitors therein without further altering the design of substrates or chips, wherein the substrates with the electronic components being carried thereon are simply made through the use of currently available element parts, materials, fabrication processes, technology, and software and hardware equipment. These substrates are much more cost-effectively fabricated than those in the prior arts, and therefore can be widely used for functional enhancement in the semiconductor devices.  
         [0071]    The invention has been described using exemplary preferred embodiments. However, it is to be understood that the scope of the invention is not limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements. The scope of the claims, therefore, should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.