Abstract:
A method of manufacturing a semiconductor device substrate includes the steps of: arranging on a base a temporary fixing member for temporarily fixing an electronic component; temporarily fixing the electronic component on the base by the temporary fixing member; forming a substrate body on the base and the electronic component; removing a portion of the base which portion corresponds to the electronic component, thereby exposing the temporary fixing member; and removing the temporary fixing member, thereby enabling the electronic component to make an external connection.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention generally relates to manufacturing methods of a semiconductor device substrate, semiconductor device substrates, and semiconductor devices, and more particularly, to a semiconductor device substrate having a base that supports a substrate body and includes an opening at a position (portion) where a semiconductor element is mounted, a manufacturing method of a semiconductor device substrate, and a semiconductor device.  
           [0003]    2. Description of the Related Art  
           [0004]    Recently, with the increase in the operational frequency of a semiconductor element mounted on a semiconductor device, it is becoming necessary to stabilize a power supply voltage supplied to such a semiconductor element. In order to correspond to the need, a structure is proposed in which an electronic component such as a capacitor element is provided in a semiconductor device substrate (a substrate for a semiconductor device) on which a semiconductor element is mounted (refer to Japanese Laid-Open Patent Application No. 04-283987, for example).  
           [0005]    However, there are problems in semiconductor devices (semiconductor device substrates) having conventional structures in that manufacturing process thereof becomes complicated, electric properties thereof are degraded, and formation of connecting terminals becomes difficult, for example.  
         SUMMARY OF THE INVENTION  
         [0006]    A general object of the present invention is to provide an improved and useful manufacturing method of a semiconductor device substrate, a semiconductor device substrate, and a semiconductor device in which one or more of the above-mentioned problems are eliminated.  
           [0007]    Another and more specific object of the present invention is to provide a manufacturing method of a semiconductor device substrate, a semiconductor device substrate, and a semiconductor device that can simplify a manufacturing process and improve characteristics of a semiconductor device.  
           [0008]    In order to achieve the above-mentioned objects, according to one aspect of the present invention, there is provided a method of manufacturing a semiconductor device substrate, the method including the steps of:  
           [0009]    arranging on a base a temporary fixing member for temporarily fixing an electronic component;  
           [0010]    temporarily fixing the electronic component on the base by using the temporary fixing member;  
           [0011]    forming a substrate body on the base and the electronic component;  
           [0012]    removing a portion of the base which portion corresponds to the electronic component, thereby exposing the temporary fixing member; and  
           [0013]    removing the temporary fixing member, thereby enabling the electronic component to make an external connection.  
           [0014]    According to an aspect of the invention, when arranging an electronic component on a base, instead of fixing the electronic component to the base by soldering, the electronic component may be temporarily fixed to the base by using a temporary fixing member. The temporary fixing member used for temporarily fixing the electronic component to the base may be removed after forming an opening in the base at a portion where the electronic component is arranged. Hence, the need for providing connecting terminals for soldering the electronic component to the base may be eliminated. The need for positioning the connecting terminals and the electronic component may also be eliminated. Accordingly, it is possible to easily manufacture a semiconductor device substrate.  
           [0015]    According to an embodiment of the invention, the temporary fixing member may be made of a metal.  
           [0016]    In an embodiment of the invention, the metal may be a low-melting metal.  
           [0017]    In an embodiment of the invention, the temporary fixing member may be a sheet member configured to be able to bond the electronic component to the base.  
           [0018]    In an embodiment of the invention, the sheet member may be a member selected from the group consisting of a thermo peeling tape, a water-soluble sheet, and a UV tape.  
           [0019]    In an embodiment of the invention, the temporary fixing member may be a liquid adhesive.  
           [0020]    Various materials may be used for the temporary fixing member. It is possible to suitably select a material of the temporary fixing member in accordance with characteristics of the electronic component.  
           [0021]    According to another aspect of the present invention, there is provided a semiconductor device substrate including:  
           [0022]    a base having an opening formed therein;  
           [0023]    an electronic component; and  
           [0024]    a substrate body arranged on the base and holding the electronic component,  
           [0025]    wherein the opening of the base is formed at a portion corresponding to the electronic component, and  
           [0026]    wherein the electronic component includes an electrode made of a single conductive material exposed at the opening.  
           [0027]    According to yet another aspect of the invention, there is provided a semiconductor device substrate including:  
           [0028]    a base having an opening formed therein;  
           [0029]    an electronic component; and  
           [0030]    a substrate body arranged on the base and holding the electronic component,  
           [0031]    wherein the opening of the base is formed at a portion corresponding to the electronic component,  
           [0032]    wherein the electronic component includes an electrode exposed to the opening, and  
           [0033]    wherein the substrate body has a cavity therein adjacent to the opening to which the electrode is exposed.  
           [0034]    According to still another aspect of the invention, an electrode of an electronic component may project from a surface of a substrate body, thereby making it possible to directly connect a semiconductor device to the electrode. Hence, it is possible to reduce impedance between the electronic component and the semiconductor element, and to improve electric properties of the semiconductor device.  
           [0035]    According to another aspect of the present invention, there is provided a semiconductor device including:  
           [0036]    a semiconductor device substrate including:  
           [0037]    a base having an opening formed therein;  
           [0038]    an electronic component; and  
           [0039]    a substrate body arranged on the base and holding the electronic component,  
           [0040]    wherein the opening of the base is formed at a portion corresponding to the electronic component, and  
           [0041]    wherein the electronic component includes an electrode made of a single conductive material; and  
           [0042]    a semiconductor element mounted on the semiconductor device substrate and electrically connected to the electrode of the electronic component.  
           [0043]    According to a further aspect of the invention, there is provided a semiconductor device including:  
           [0044]    a semiconductor device substrate including:  
           [0045]    a base having an opening formed therein;  
           [0046]    an electronic component; and  
           [0047]    a substrate body arranged on the base and holding the electronic component,  
           [0048]    wherein the opening of the base is formed at a portion corresponding to the electronic component,  
           [0049]    wherein the electronic component includes an electrode, and  
           [0050]    wherein the substrate body has a cavity therein adjacent to the opening; and  
           [0051]    a semiconductor element mounted on the semiconductor device substrate and electrically connected to the electrode of the electronic component.  
           [0052]    According to still another aspect of the invention, an electrode of an electronic component may project from a surface of the substrate body, thereby making it possible to directly connect a semiconductor device to the electrode. Hence, it is possible to reduce impedance between the electronic component and the semiconductor element, and to improve electric properties of the semiconductor device.  
           [0053]    Other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the following drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0054]    [0054]FIGS. 1A, 1B,  1 C,  1 D,  1 E,  1 F,  1 G, and  1 H are schematic diagrams for explaining a manufacturing method of a semiconductor device substrate, the semiconductor device substrate, and a semiconductor device;  
         [0055]    [0055]FIGS. 2A, 2B,  2 C,  2 D,  2 E,  2 F,  2 G,  2 H,  2 I and  2 J are schematic diagrams for explaining a manufacturing method of a semiconductor device substrate, a semiconductor device substrate, and a semiconductor device according to a first embodiment of the present invention;  
         [0056]    [0056]FIGS. 3A, 3B,  3 C,  3 D,  3 E,  3 F,  3 G,  3 H, and  3 I are schematic diagrams for explaining a manufacturing method of a semiconductor device substrate, a semiconductor device substrate, and a semiconductor device according to a second embodiment of the present invention;  
         [0057]    [0057]FIGS. 4A, 4B,  4 C,  4 D,  4 E,  4 F,  4 G,  4 H, and  4 I are schematic diagrams for explaining a manufacturing method of a semiconductor device substrate, a semiconductor device substrate, and a semiconductor device according to a third embodiment of the present invention;  
         [0058]    [0058]FIGS. 5A, 5B,  5 C,  5 D,  5 E,  5 F,  5 G,  5 H and  5 I are schematic diagrams for explaining a manufacturing method of a semiconductor device substrate, a semiconductor device substrate, and a semiconductor device according to a fourth embodiment of the present invention;  
         [0059]    [0059]FIG. 6 is a schematic diagram showing the semiconductor device according to the first embodiment of the present invention in an enlarged manner; and  
         [0060]    [0060]FIG. 7 is a schematic diagram showing greater detail of an electronic component mounted in the semiconductor device according to the first embodiment of the present invention in an enlarged manner. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0061]    [0061]FIGS. 1A through 1H are schematic diagrams for explaining a manufacturing method of a semiconductor device substrate and a semiconductor device suggested by the inventors of the present invention.  
         [0062]    [0062]FIG. 1H shows a semiconductor device  1  provided with an electronic component, and a semiconductor device substrate (hereinafter simply referred to as a “substrate”)  3 . In the semiconductor device  1  shown in FIG. 1H, a capacitor element is provided as the electronic component.  
         [0063]    In the semiconductor device  1 , a semiconductor element  2  is mounted in an opening  9  formed in the substrate  3 . The substrate  3  includes a substrate body  5 , a base  6 , and an electronic component  7 .  
         [0064]    The base  6  is provided for supporting the substrate body  5 . For this reason, the base  6  is formed by a metal (copper, for example) having a mechanical strength higher than that of the substrate body  5 . The opening  9  is formed in the base  6  at an element mounting position where the semiconductor element  2  is mounted.  
         [0065]    The electronic component  7  is embedded in the substrate body  5  except for connecting terminals  8  connected to bumps  13 . The electronic component  7  includes a silicon core  10  and the bumps  13  formed on the silicon core  10 . The connecting terminals  8  are provided on the bumps  13  (on the exposed sides of the bumps  13 ). The connecting terminals  8  are exposed at the substrate body  5  in the opening  9 .  
         [0066]    In order to mount the semiconductor element  2  on the substrate  3 , as shown in FIG. 1G, conductive members  12  (solders, for example) are arranged on the connecting terminals  8  exposed at the substrate body  5 , and bumps  4  are bonded to the connecting terminals  8  via the conductive members  12 . Consequently, the semiconductor element  2  is flip-chip bonded to the substrate  3 .  
         [0067]    In the semiconductor device  1  having the above-mentioned structure, the electronic component  7 , which is a capacitor element, is positioned beneath the semiconductor element  2 . Hence, it is possible to stabilize a power supply voltage supplied to the semiconductor element  2  by the electronic component  7  (capacitor element), and improve electric properties and reliability of the semiconductor device  1 .  
         [0068]    [0068]FIGS. 1A through 1G show the manufacturing method of the substrate  3 . When manufacturing the substrate  3 , the base  6 , which is formed by copper (Cu) and shown in FIG. 1A, is prepared. Then, as shown in FIG. 1B, the connecting terminals  8  are formed on the base  6 .  
         [0069]    Specifically, a conductive metal, which forms the connecting terminals  8 , is plated over a top surface of the base  6 . Subsequently, a resist is applied and patterning is performed on the resist by using a photo lithography technique. Then, the conductive metal is etched by using the patterned resist as a mask. Thereafter, by performing resist separation, the connecting terminals  8  are formed. The positions where the connecting terminals  8  are formed are selected to correspond to the positions where the bumps  13  are formed on the electronic component  7 .  
         [0070]    When the connecting terminals  8  are formed on the base  6 , subsequently, as shown in FIGS. 1C and 1D, the electronic component  7  is mounted on the base  6 . As mentioned above, the electronic component  7  includes the bumps  13  and the silicon core  10  having the capacitor element. The electronic component  7  is manufactured in advance in a process different from the manufacturing process of the substrate  3 . Since the bumps  13  are solder bumps, the electronic component  7  is bonded to the base  6 .  
         [0071]    When the electronic component  7  is mounted on the base  6 , as shown in FIG. 1E, the substrate body  5  is formed by stacking the wiring layer such as by vias and an insulating resin member (not shown) by using the build-up method on the side of the base  6  on which the electronic component  7  is mounted. As a result, the electronic component  7  is embedded in the substrate body  5 .  
         [0072]    Subsequently, as shown in FIG. 1F, the opening  9  is formed in the base  6  at the position where the semiconductor element  2  is to be mounted. Since the opening  9  is formed in the base  6 , the connecting terminals  8  that are electrically bonded to the bumps  13  of the electronic component  7  are exposed. Hence, it becomes possible to mount the semiconductor element  2  on the substrate  3 . With the series of processes mentioned above, the substrate  3  is manufactured.  
         [0073]    In order to mount the semiconductor element  2  on the substrate  3  manufactured as mentioned above, since surfaces of the connecting terminals  8  and a surface of the substrate body  5  form a substantially identical surface, the conductive members  12  are formed on the connecting terminals  8  as shown in FIG. 1G. Subsequently, as shown in FIG. 1H, the semiconductor element  2  is flip-chip bonded to the substrate  3 . On this occasion, since the connecting terminals  8  protrude from the bumps  13 , it is possible to improve bonding characteristics between the bumps  4  of the semiconductor element  2  and the connecting terminals  8 .  
         [0074]    As mentioned above, manufacturing methods of the semiconductor device substrate  3  use as a method for fixing the electronic component  7  to the base  6  a method of mounting the electronic component  7  on the connecting terminals  8  after forming the connecting terminals  8  on. the base  6   
         [0075]    With such a manufacturing method, however, it is inevitably necessary to form the connecting terminals  8  on the base  6 . It is also necessary that the formation positions of the connecting terminals  8  match the formation positions of the bumps  13  that are formed on the electronic component  7 . Hence, there may be a problem in that the manufacturing process of the substrate  3  may become complicated.  
         [0076]    In addition, with the recent increase in the density of a semiconductor element, the number of bumps  4  provided for the semiconductor element  2  shows a tendency to be increased. Accordingly, the number of the bumps  13  formed to correspond to the bumps  4  is also increased, which means it would be desirable to form the connecting terminals  8  on the base  6  with a high density. In this regard, a high degree of accuracy is required in forming the connecting terminals  8 . Thus, there may be a problem in that formation of the connecting terminals  8  may become difficult.  
         [0077]    Further, with the manufacturing method, as shown in FIGS. 1F through 1H, the connecting terminals  8  remain by necessity. In addition, the connecting terminals  8  form the substantially identical surface with the surface of the substrate body  5  which surface is exposed at the opening  9 . Hence, the conductive members  12  are provided on the connecting terminals  8  so as to increase bonding characteristics between the semiconductor element  2  and the connecting terminals  9 . Thus, there may be a problem in that the manufacturing process may be complicated.  
         [0078]    Additionally, in the structure, as shown in FIG. 1H, two kinds of members, i.e., the connecting terminals  8  and the conductive members  12 , lie between the bumps  4  of the semiconductor element  2  and the bumps  13  of the electronic component  7 . Hence, impedance between the semiconductor element  2  and the electronic component  7  may become high. Thus, there may be a problem in that electric properties of the semiconductor device  1  may be degraded.  
         [0079]    A description is given below of a first embodiment of the present invention, with reference to the drawings.  
         [0080]    [0080]FIGS. 2A through 2J are schematic diagrams for explaining a manufacturing method of a semiconductor device substrate (a substrate for a semiconductor device) (hereinafter simply referred to as a “substrate”)  23 A, the substrate  23 A, and a semiconductor device  20 A according to a first embodiment of the present invention. FIGS. 2A through 2H show the manufacturing method of the substrate  23 A. FIG. 2I shows the substrate  23 A. FIGS. 2J, 6 and  7  show the semiconductor device  20 A.  
         [0081]    Referring to FIGS. 2I, 2J,  6  and  7 , a description is given below of the structures of the substrate  23 A and the semiconductor device  20 A according to this embodiment. As shown in FIGS. 2J, 6 and  7 , the semiconductor device  20 A generally includes the substrate  23 A, and a semiconductor element  22  mounted in an opening  29  formed in the substrate  23 A.  
         [0082]    The substrate  23 A includes a substrate body  25 , a base  26 , and an electronic component  27 . As shown in FIG. 6 in an enlarged manner, the substrate body  25  is formed by stacking a plurality of (three, in the exemplary embodiment shown in FIG. 6) insulating resin members  25 A through  25 C and internal wiring layers  46  (including vias) by a build-up method on one side of the base  26 . Solder balls  48  for external connection, which are connected to the internal wiring layers  46 , are formed on the side of the substrate body  25  that is opposite to a surface on which the semiconductor element  22  is mounted. In FIG. 6, a reference numeral  47  designates a protective film.  
         [0083]    The base  26  is provided for supporting the substrate body  25 . The base  26  is formed by a metal (copper, for example) having a mechanical strength greater than that of the insulating resin members  25 A through  25 C, which form a major portion of the substrate body  25 . The opening  29  is formed in the base  26  at the position where the semiconductor element  22  is mounted.  
         [0084]    In this embodiment, the electronic component  27  is a capacitor. As shown in FIG. 7 in an enlarged manner, capacitor elements  50 , bumps  33 , which serve as electrodes, and the like are formed on a silicon core  30  to form the electronic component  27 . The capacitor element  50  is formed on a surface (hereinafter referred to as an “element forming surface”)  27   a  of the silicon core  30 .  
         [0085]    The electronic component  27  is mounted on the substrate body  25  with a part of the electronic component  27  embedded in the substrate body  25 . However, since a concave portion  37  (FIG. 6) is formed in the substrate body  25  as is described below, the bumps  33  are exposed at the substrate body  25 . Thus, the bumps  33  project from the element forming surface  27   a.    
         [0086]    Bumps  24  are formed on a circuit forming surface of the semiconductor element  22  (a bottom surface of the semiconductor element  22  shown in FIG. 2J). The bumps  24  may be, for example, solder bumps, gold bumps, and/or bumps made of another metal.  
         [0087]    The semiconductor element  22  is inserted into the opening  29  formed in the base  26 , and fixed to the substrate  23 A by bonding the bumps  24  to the bumps  33 . In the semiconductor device  20 A according to this embodiment, the semiconductor element  22  is flip-chip bonded to the substrate  23 A.  
         [0088]    By bonding the semiconductor element  22  to the electronic component  27  in the aforementioned manner, the electronic component  27  functions as a decoupling capacitor. Accordingly, it is possible to stabilize by the electronic component  27  a power supply voltage supplied to the semiconductor element  22 . Hence, it is possible to improve reliability of the semiconductor device  20 .  
         [0089]    The electronic component  27  is arranged beneath the semiconductor element  22 . Hence, the distances of conductive channels between the semiconductor element  22  and the capacitor elements  50  (FIG. 7) are short, and an inductance thereof is small. Thus, even if the operational frequency of the semiconductor element  22  is increased, it is possible to stabilize the power supply voltage supplied to the semiconductor element  22  with little or no affect by the inductance.  
         [0090]    In the illustrated exemplary embodiment, when flip-chip bonding the semiconductor element  22  to the substrate  23 A, since the concave portion  37  is formed in the substrate body  25 , the bumps  33  project from the element forming surface  27   a . Hence, bonding may be obtained between the bumps  33  and the semiconductor element  22 . More particularly, it is possible to directly connect the bumps  24  of the semiconductor element  22  to the bumps  33  of the electronic component  27 .  
         [0091]    That is, it is possible for the substrate  23 A and the semiconductor device  20 A according to this embodiment to eliminate the need for the connecting terminals  8  and the conductive members  12 . Hence, it is possible to reduce impedance between the semiconductor element  22  and the electronic component  27 , and improve electric properties of the semiconductor device  20 A.  
         [0092]    The capacitor elements  50  formed on the silicon core  30  of the electronic component  27  are electrically connected to a surface opposite to the element forming surface  27   a  via penetrating vias  49  formed to penetrate the silicon core  30 . The penetrating vias  49  are connected to the vias formed in the substrate body  25  and serving as internal wiring, and external connection is made by the vias formed in the substrate body  25 .  
         [0093]    A description is given below of the manufacturing method of the substrate  23 A having the above-mentioned configuration. When manufacturing the substrate  23 A, the base  26  is prepared as shown in FIG. 2A. The base  26  is formed by a metal such as copper having a mechanical strength greater than that of the substrate body  25 .  
         [0094]    As shown in FIG. 2B, an insulating member  34  having an opening pattern  35  is formed on a top surface of the base  26 . The formation position of the opening pattern  35  is set to correspond to the position where the bumps  33  of the electronic component  27  are to be bonded.  
         [0095]    Subsequently, by performing a plating process, a metal material  36 , which serves as a temporary fixing member, is formed in the opening pattern  35  formed in the insulating member  34 . An electrolytic plating method or an electroless plating method, for example, may be used in the plating process. It is preferable to use a low-melting material, a brazing material, for example, as a material of the metal material  36 . Tin (Sn), for example, may be used as a material of the metal material  36 .  
         [0096]    When the metal material  36  is formed with a predetermined shape on the base  26  by the plating process, the insulating member  34  is removed as shown in FIG. 2D. Consequently, the metal material  36  is arranged on the base  26  at the position where the bumps  33  of the electronic component  27  are to be bonded.  
         [0097]    Subsequently, as shown in FIG. 2E, the electronic component  27  is mounted on the base  26  on which the metal material  36  is formed. In the illustrated exemplary embodiment, the metal material  36  is melted or softened by performing a heating process, and the electronic component  27  is pressed against the base  26 . As a result, the bumps  33  push aside the metal material  36  and abut a surface  26   a  of the base  26 .  
         [0098]    By performing a cooling process under the above-mentioned state, the metal material  36  is cured again and holds the bumps  33 . Thus, the electronic component  27  is temporarily fixed to the base  26  by the metal material  36 . In the illustrated exemplary embodiment, since the bumps  33  formed on the electronic component  27  abut the surface  26   a , the degree of parallelization of the electronic component  27  with respect to the base  26  is maintained.  
         [0099]    Referring to FIG. 2F, when the electronic component  27  is temporarily fixed to the base  26  in the aforementioned manner, a formation process of the substrate body  25  is subsequently performed on the base  26 . The formation process of the substrate body  25  is performed by stacking vias and insulating resin members on one side of the base  26  by a build-up method, while using as a core substrate the base  26  on which the electronic component  27  is arranged.  
         [0100]    In accordance with the present invention, since the electronic component  27  is temporarily fixed to the base  26 , it is possible to positively perform the formation process of the substrate body  25 . In addition, since the electronic component  27  is temporarily fixed to the base  26  with a good accuracy, it is possible to positively electrically connect the vias (not shown) formed in the substrate body  25  to the penetrating vias (not shown) formed in the electronic component  27 .  
         [0101]    When the substrate body  25  is formed on the base  26  in the aforementioned manner, resist is subsequently formed on the base  26  except for the portion where the opening  29  is to be formed (opening forming portion). By using the resist as a mask, an etching process is performed on the base  26 . Consequently, as shown in FIG. 2G, the opening  29  is formed in the base  26 . With such a state, the metal material  36  and the bumps  33  are exposed at the opening  29  to form a substantially uniform surface.  
         [0102]    Subsequently, as shown in FIG. 2H, an etching process for removing the metal material  36  is performed. An etchant that in the exemplary embodiment dissolves Tin (Sn) is selected as the etchant in the etching process. Hence, the metal material  36  is removed, thereby leaving the bumps  33  and the silicon core  30 .  
         [0103]    By performing the series of processes mentioned above, the substrate  23 A is manufactured, and the semiconductor element  22  may be mounted thereon (connected thereto). FIG. 2I shows a state where the substrate  23 A is completed. As shown in FIG. 2I, by removing the metal material  36 , the concave portion  37  is formed in the substrate body  25 . Additionally, formation of the concave portion  37  results in projection of the bumps  33  of the electronic component  27  from the element forming surface  27   a . Accordingly, as mentioned above, it is possible to improve bonding and reliability in mounting the semiconductor element  22  on the substrate  23 A.  
         [0104]    As mentioned above, in this embodiment, when arranging the electronic component  27  on the base  26 , instead of forming the connecting terminals  8  on the base  6  and fixing the electronic component  7  to the connecting terminals  8  by soldering (refer to FIGS. 1A through 1H), according to the exemplary embodiment of the present invention, a method is used in which the electronic component  27  is temporarily fixed to the base  26  by using the metal material  36  serving as the temporary fixing member.  
         [0105]    The manufacturing method according to this embodiment eliminates the need for the process of forming the connecting terminals  8 . Thus, it is possible to simplify the manufacturing processes of the substrate. In addition, the processes for positioning the connecting terminals  8  and the bumps  13  are also eliminated, which also simplifies the manufacturing processes of the substrate. Further, in this embodiment, the bumps  33  are temporarily fixed to the base  26  by making the bumps  33  directly abut the base  26 . Hence, it is easy to correspond to the semiconductor element  22  having a higher density (that is, the bumps  33  arranged with a higher density).  
         [0106]    In the above-mentioned embodiment, Tin (Sn) is used as the metal material  36 , which serves as the temporary fixing member. However, Tin is not a limitation of the metal material  36 , and various metals may be used. In order to perform the temporary fixing process easily, it is preferable that a low-melting material such as solder is selected as the metal material  36 . Additionally, it is preferable for the metal material  36  to be easily removed without affecting the bumps  33  and the electronic component  27  and without leaving residue in the process for removing the metal material  36 .  
         [0107]    Next, a description is given below of a second embodiment of the present invention.  
         [0108]    [0108]FIGS. 3A through 3I are diagrams for explaining a substrate  23 B, a semiconductor device  20 B, and a manufacturing method of the substrate  23 B. FIGS. 3A through 3G show the manufacturing method of the substrate  23 B. FIG. 3H shows the substrate  23 B, and FIG. 3I shows the semiconductor device  20 B.  
         [0109]    In FIGS. 3A through 3I, referred to for explaining the second embodiment, and FIGS. 4 and 5, referred to in a description of third and following embodiments of the present invention, those parts that are the same as those corresponding parts in FIGS. 2A through 2J are designated by the same reference numerals, and a description thereof is omitted.  
         [0110]    In the above-mentioned first embodiment, the metal material  36  (Tin) is used as the temporary fixing member that fixes the electronic component  27  to the base  26 . On the other hand, in the second embodiment, a sheet member is used as the temporary fixing member. For example, a water-soluble sheet  40  may be used as the sheet member.  
         [0111]    A description is given below of the manufacturing method of the substrate  23 B according to the second embodiment.  
         [0112]    In the second embodiment, after preparing the base  26  as shown in FIG. 3A, a cavity (depression)  38  is formed in the base  26  as shown in FIG. 3B by, for example, spot facing or etching. The formation portion of the cavity  38  is set to correspond to the portion where the bumps  33  of the electronic component  27  is to be bonded.  
         [0113]    As shown in FIG. 3C, the water-soluble sheet  40  is arranged in the cavity  38 . PVA (polyvinyl alcohol) or No. 509A manufactured by Nitto Denko Corporation may be used as the water-soluble sheet  40 , for example. Each of such above-mentioned water-soluble sheets has adhesion properties and characteristics of being dissolved into water when dipped into water. Since the water-soluble sheet  40  has adhesion properties, the water-soluble sheet  40  adheres to the base  26  (in the cavity  38 ) while being arranged in the cavity  38 .  
         [0114]    When the water-soluble sheet  40  is arranged on the base  26  in the aforementioned manner, the electronic component  27  is mounted on the base  26  as shown in FIG. 3D. Consequently, the bumps  33  of the electronic component  27  abut the water-soluble sheet  40 . As mentioned above, the water-soluble sheet  40  has adhesive properties. Hence, when the bumps  33  abut the water-soluble sheet  40 , the electronic component  27  is temporarily fixed to the base  26  via the water-soluble sheet  40 .  
         [0115]    When the electronic component  27  is temporarily fixed to the base  26  in the aforementioned manner, the substrate body  25  is formed on the base  26  (FIG. 3E). The opening  29  is then formed in the base  26  (FIG. 3F) as in the first embodiment. With such a state, the water-soluble sheet  40  is exposed at the opening  29 , and the bumps  33  are covered by the water-soluble sheet  40 .  
         [0116]    Subsequently, a process is performed in which the base  26 , which exposes the water-soluble sheet  40  at the opening  29 , is dipped into water, thereby removing the water-soluble sheet  40 . By performing the series of processes mentioned above, the substrate  23 B is manufactured, and the semiconductor element  22  may be mounted thereon (connected thereto). FIG. 3G shows a state where the substrate  23 B is completed.  
         [0117]    In the removing process of the water-soluble sheet  40 , the water-soluble sheet  40  should be merely dipped into water. Thus, it is possible to perform the removing process easily. Additionally, since the solvent for the water-soluble sheet  40  is water, the substrate body  25 , the electronic component  27 , and the bumps  33  are not deleteriously affected. Further, it is not necessary to perform a heating process when temporarily fixing the electronic component  27  to the water-soluble sheet  40  and when dissolving the water-soluble sheet  40  into water. Hence, it is possible to prevent the electronic component  27  from being damaged due to heat.  
         [0118]    As shown in FIG. 3G, the bumps  33  are exposed by removing the water-soluble sheet  40 . In the illustrated exemplary embodiment, the tops of the bumps  33  form a substantially uniform surface with an exposed surface  41 a of the substrate body  25 . Hence, when mounting the semiconductor element  22 , conductive members  32  (solders, for example) are formed on the bumps  33  as shown in FIG. 3H so as to enable bonding between the bumps  24  of the semiconductor element  22  and the bumps  33  of the electronic component  27 . Then, the semiconductor element  22  is mounted on the substrate  23 B via the conductive members  32 .  
         [0119]    The manufacturing method according to the second embodiment also eliminates the need for the connecting terminals  8 . Accordingly, it is possible to simplify the manufacturing process of the substrate, and easily correspond to a semiconductor element  22  having a higher density (that is, the bumps  33  arranged with a higher density).  
         [0120]    A description is given below of a third embodiment of the present invention.  
         [0121]    [0121]FIGS. 4A through 4I are diagrams for explaining a substrate  23 C, a semiconductor device  20 C, and a manufacturing method of the substrate  23 C according to the third embodiment of the present invention. FIGS. 4A through 4G show the manufacturing method of the substrate  23 C. FIG. 4H shows the substrate  23 C, and FIG. 4I shows the semiconductor device  20 C.  
         [0122]    The manufacturing method according to the third embodiment uses a sheet member as the temporary fixing member as in the second embodiment. In the second embodiment, the cavity  38  is formed in the base  26 , and the water-soluble sheet  40 , which is the sheet member, is arranged in the cavity  38 . In the third embodiment, however, the cavity  38  is not formed and a sheet member is arranged on the base  26 .  
         [0123]    A description is given below of the manufacturing method of the substrate  23 C according to the third embodiment.  
         [0124]    In the third embodiment, after preparing the base  26  as shown in FIG. 4A, a sheet member  42  is arranged on a top surface of the base  26  as shown in FIG. 4B. In this embodiment, a thermo-peeling tape (thermal release tape)  42  is used as the sheet member that serves as the temporary fixing member.  
         [0125]    The thermo-peeling tape  42  is a sheet member (tape member) that has adhesive properties at normal temperatures and has characteristics that the adhesive properties are degraded when subjected to a heating process (at 170° C., for example). “Revalpha (product name)” manufactured by Nitto Denko Corporation, for example, may be used as the thermo-peeling tape  42 . As mentioned above, since the thermo-peeling tape  42  has adhesive properties at normal temperatures, the thermo-peeling tape  42  adheres to the base  26  while being arranged on the base  26 .  
         [0126]    When the thermo-peeling tape  42  is arranged on the base  26  in the aforementioned manner, the electronic component  27  is mounted on the base  26  as shown in FIGS. 4C and 4D. Consequently, the bumps  33  of the electronic component  27  abut the thermo-peeling tape  42 . As mentioned above, the thermo-peeling tape  42  has the adhesive properties. Thus, when the bumps  33  abut the thermo-peeling tape  42 , the electronic component  27  is temporarily fixed to the base  26  via the thermo-peeling tape  42 .  
         [0127]    When the electronic component  27  is temporarily fixed to the base  26  in the aforementioned manner, the substrate body  25  is formed on the base  26  (FIG. 4E). The opening  29  is then formed in the base  26  (FIG. 4F) as in each of the above-mentioned embodiments. With such a state, the thermo-peeling tape  42  is exposed at the opening  29 , and the bumps  33  are covered by the thermo-peeling tape  42 .  
         [0128]    Subsequently, a heating process is performed at approximately 170° C. or other temperature depending on the particular thermo-peeling tape used, thereby reducing the adhesion force of the thermo-peeling tape  42 , and separating the thermo-peeling tape  42  from the substrate body  25 . Since the adhesive force of the thermo-peeling tape  42  is reduced by the heating process, it is possible to easily perform separation of the thermo-peeling tape  42 . By performing the series of processes mentioned above, the substrate  23 C is manufactured, and the semiconductor element  22  may be mounted thereon (connected thereto). FIG. 4G shows a state where the substrate  23 C is completed.  
         [0129]    As shown in FIG. 4G, by separating the thermo-peeling tape  42 , a stage portion  44  is formed in the substrate body  25 , and the bumps  33  are exposed at an exposed surface  41   b  of the substrate body  25 . In the illustrated exemplary embodiment, the tops of the bumps  33  form a substantially uniform surface with the exposed surface  41   b  of the substrate body  25 . Hence, also in this embodiment, as shown in FIG. 4H, the conductive members (solders, for example)  32  are formed on the bumps  33 , and the semiconductor element  22  is mounted on the substrate  23 C via the conductive members  32 .  
         [0130]    The manufacturing method according to this embodiment also eliminates the need for the connecting terminals  8 . Hence, it is possible to simplify the manufacturing process of the substrate, and easily correspond to a semiconductor element  22  having a higher density (that is, the bumps  33  arranged with a higher density).  
         [0131]    In the second and third embodiments mentioned above, the description is given of the cases where the water-soluble sheet  40  and the thermo-peeling tape  42  are used as the sheet member, respectively. However, the above-mentioned sheets are not limitations of the sheet member, and other sheet members may be used such as a UV tape whose adhesive force is reduced when subjected to ultraviolet light. Additionally, the method for removing the sheet member is not limited to dipping the sheet member into water and heating the sheet member, as other methods may be used such as removing by laser beam machining and removing by dry etching.  
         [0132]    A description is given below of a fourth embodiment of the present invention.  
         [0133]    [0133]FIGS. 5A through 5I are diagrams for explaining a substrate  23 D, a semiconductor device  20 D, and a manufacturing method of the substrate  23 D according to the fourth embodiment. FIGS. 5A through 5G show the manufacturing method of the substrate  23 D. FIG. 5H shows the substrate  23 D, and FIG. 5I shows the semiconductor device  20 D.  
         [0134]    The manufacturing method according to this embodiment uses a liquid adhesive  43  as the temporary fixing member. In this embodiment, a spray glue  43  is used as the liquid adhesive, which serves as the temporary fixing member.  
         [0135]    A description is given below of the manufacturing method of the substrate  23 D.  
         [0136]    In this embodiment, after preparing the base  26  as shown in FIG. 5A, a mask  45  is formed on a top surface of the base  26  as shown in FIG. 5B. Then, the spray glue  43  is provided in an opening pattern  51  formed by the mask. It is preferable that the amount of the spray glue  43  to be provided is such an amount by which the bumps  33  are positively embedded therein, and the spray glue  43  does not overflows when the electronic component  27  is mounted on the base  26  as shown in FIG. 5D.  
         [0137]    In the exemplary embodiment, the spray glue  43  is a liquid adhesive having acrylic rubber as its principal component, for example. By spraying the spray glue  43  toward the mask  45  by using a spray apparatus, the spray glue  43  is deposited in the opening pattern  51 . In accordance with the present invention, by suitably setting the arranging position and the shape of the opening pattern  51 , it is possible to provide the spray glue  43  to an arbitrary portion of the base  26 .  
         [0138]    When the spray glue  43  is provided for the base  26  in the aforementioned manner, the mask  45  is removed. Then, as shown in FIGS. 5C and 5D, the electronic component  27  is mounted on the base  26 . Consequently, the bumps  33  of the electronic component  27  enter the spray glue  43  and abut the surface  26   a  of the base  26 .  
         [0139]    Since the spray glue  43  has adhesive properties, when the bumps  33  enter and push aside the spray glue  43 , and the spray glue  43  contacts the element forming surface  27   a  of the electronic component  27 , the electronic component  27  is temporarily fixed to the base  26  via the spray glue  43 .  
         [0140]    When the electronic component  27  is temporarily fixed to the base  26  in the aforementioned manner, the substrate body  25  is formed on the base  26  (FIG. 5E). The opening  29  is then formed in the base  26  (FIG. 5F) as in each of the above-mentioned embodiments. With such a state, the spray glue  43  and the tops of the bumps  33  are exposed at the opening  29 .  
         [0141]    The base  26  is dipped into a solvent of ethanol or acetone, for example, and preferably ultrasonic cleaning is performed thereon. Consequently, the spray glue  43  is washed away and removed from the substrate body  25  and the electronic component  27 . By performing the series of processes mentioned above, the substrate  23 D is manufactured. FIG. 5G shows a state where the substrate  23 D is completed.  
         [0142]    As shown in FIG. 5G, by removing the spray glue  43 , the stage portion  44  is formed in the substrate body  25 , and the bumps  33  project from the element forming surface  27   a  of the substrate body  25 . Accordingly, when mounting the semiconductor element  22  on the substrate  23 D, it is possible to directly bond the bumps  24  and the bumps  33 . Hence, it is possible to improve bonding and reliability.  
         [0143]    The manufacturing method according to this embodiment also eliminates the need for the connecting terminals  8 . Hence, it is possible to simplify the manufacturing process of the substrate, and easily correspond to the semiconductor element  22  having a higher density (that is, the bumps  33  arranged with a higher density).  
         [0144]    In each of the above-mentioned embodiments of the manufacturing method of a substrate, the description is given by taking as examples the manufacturing methods of the semiconductor device substrates  23 A through  23 D on which the semiconductor element  22  is mounted. However, application of the manufacturing method of a substrate according to the present invention is not limited to a semiconductor device substrate. As will be appreciated, the manufacturing method of a substrate according to the present invention may be applied to manufacturing of a substrate on which the semiconductor element  22  is not mounted.  
         [0145]    Additionally, in the above-mentioned embodiments, the electrodes of the electronic component  27  are bumps. However, the present invention may be applied to a case where the electrodes of the electronic component  27  are formed by other than bumps, as will be appreciated.  
         [0146]    Further, in the above-mentioned embodiments, the opening  29  is formed, thereby leaving the base  26  except for the formation portion of the opening  29 . However, the base  26  may be completely removed.  
         [0147]    According to the present invention, it is possible to achieve various effects.  
         [0148]    In an embodiment of the present invention, when mounting the electronic component  27  on the base  26 , instead of fixing the electronic component  27  to the base  26  by soldering as in conventional methods, the electronic component  27  is temporarily fixed to the base by using the temporary fixing member (for example,  36 ,  40 ,  42 ,  43 ). Additionally, the temporary fixing member (for example,  36 ,  40 ,  42 ,  43 ), which is used for temporarily fixing the electronic component  27  to the base  26 , is removed after the opening  29  is formed in base  26  at the arranging portion of the electronic component  27 . Hence, the need for providing the base  26  with the connecting terminals  8  for soldering is eliminated, and the need for positioning the connecting terminals  8  and the electronic component  27  is also eliminated. Accordingly, it is possible to easily manufacture a substrate (for example,  23 A,  23 B,  23 C,  23 D).  
         [0149]    In an embodiment of the present invention, the electrodes of the electronic component  27  may project from the surface of the substrate body  25 . Hence, it is possible to directly connect the electrodes to the semiconductor element  22 . Accordingly, it is possible to reduce impedance between the electronic component  27  and the semiconductor element  22 , and improve electric properties of the semiconductor device (for example,  20 A,  20 B,  20 C,  20 D).  
         [0150]    The present invention is not limited to the specifically disclosed embodiments, and variations and modifications may be made without departing from the scope of the present invention.  
         [0151]    The present application is based on Japanese priority application No. 2003-104070 filed on Apr. 8, 2003, the entire contents of which are hereby incorporated by reference.