Abstract:
A semiconductor device in which overall thickness is reduced by suppressing the rising of a metal thin line and connection reliability is enhanced at the joint of metal thin line and other member during resin sealing. A method for manufacturing such semiconductor device is also provided. The semiconductor device ( 10 A) comprises electrodes ( 12 A,  12 B,  12 C), a semiconductor chip ( 13 ) bonded to the upper surface of the electrode ( 12 A) formed in the shape of island, a metal thin line ( 15 A) connecting the semiconductor chip ( 13 ) and the electrode ( 12 C), a metal thin line ( 15 B) connecting the semiconductor chip ( 13 ) and the electrode ( 12 B), and a sealing resin ( 11 ) supporting those elements mechanically by sealing them integrally. The metal thin lines ( 15 A,  15 B) have planar shape curved convexly toward the upstream of the flow if the sealing resin ( 11 ) to be injected.

Description:
REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a national stage application under 35 USC 371 of International Application No. PCT/JP2007/069427, filed Sep. 27, 2007, which claims priority from Japanese Patent Application Number JP 2006-356732, filed Dec. 29, 2006, the contents of which are incorporated herein by reference in their entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to a semiconductor device and a method of manufacturing the same, and more particularly to a semiconductor device having an improvement in the reliability of connection by a fine metal wire and a method of manufacturing the same. 
       BACKGROUND OF THE INVENTION 
       [0003]    Generally, a semiconductor device uses a fine metal wire for an electrical connection between a semiconductor chip and an electrode sealed within the semiconductor device. The fine metal wire has a long history of technological change, as distinct from a bump electrode or the like for use in flip chip or other applications, and thus is even now in use because of its reliability. 
         [0004]    One example is shown for instance in  FIGS. 14 and 15 .  FIG. 14  is a plan view of a semiconductor device  100  as seen from above, and  FIG. 15  is a cross-sectional view thereof. As shown by a rectangular shape, reference numeral  103  denotes a semiconductor chip, which is here described as a transistor device. A bipolar transistor, a MOS transistor, or the like, for example, is employed as the semiconductor chip  103 . 
         [0005]    Three electrodes electrically connected to the above-mentioned semiconductor chip  103  are embedded within the semiconductor device  100 . An island-shaped electrode  102 A electrically, fixedly bonded to the underside of the above-mentioned semiconductor chip  103  is located on the left edge, and two electrodes  102 B and  102 C are located on the right edge. In other words, the electrode  102 A forms a collector electrode, and the other electrodes  102 B and  102 C form an emitter electrode and a base electrode, respectively. Then, two bonding pads of the semiconductor chip  103  are connected respectively via fine metal wires  105 A and  105 B to the electrode  102 C and the electrode  102 B. 
         [0006]    Then, the electrodes  102 A,  102 B and  102 C, the semiconductor chip  103 , and the fine metal wires  105 A and  105 B are integrally sealed with a sealing resin  101 . In addition, the electrodes  102 A,  102 B and  102 C are partially exposed to the outside from the sealing resin  101 . 
         [0007]    The fine metal wires  105 A and  105 B undergo ball bonding on the bonding pads of the semiconductor chip  103 , and extend upward and then downward to inner leads (or the electrodes  102 B and  102 C) for stitch bonding, so that the height H of the peak of the fine metal wire  105 A or the like above the top surface of the semiconductor chip  103  is relatively high, that is, from 100 to 150 μm (See  FIG. 15 ). 
         [0008]    Japanese Patent Application Publication No. Hei 9-298256 discloses, in  FIGS. 1 and 2 , a package in which the inner leads are disposed on both sides of the island; however, as is apparent also from  FIG. 2 , the shape of the fine metal wire is likewise parabolic, which in turn leads to limitation in the thickness of the package. 
         [0009]    However, considering a manufacturing method for the above-mentioned semiconductor device, there is a problem of breaking of the fine metal wires  105 A and  105 B in formation of the sealing resin  101  for sealing the semiconductor chip  103  and so on. 
         [0010]    The specific description is as follows. Four arrows shown in  FIG. 14  indicate the direction of resin injection, and a rectangular region located directly under the arrows represents a gate  106 . Resin sealing of the semiconductor chip  103  and so on involves loading the semiconductor chip  103 , the electrode  102 A, and so on in a cavity of a molding die, and injecting the sealing resin  101  in liquid form from the gate into the cavity, thereby effecting the sealing thereof with the sealing resin  101 . 
         [0011]    Resin pressures for injection from the gate  106  are of various magnitudes, and high resin injection pressure may lead to bending or breaking of the fine metal wire  105 A or the like; however, under the present circumstances, a fine wire of relatively great thickness is used as the fine metal wire  105 A or the like thereby to suppress the breaking or the like. Also, the thickness, shape or other configuration of the fine metal wire  105 A is determined by the relative positions of the bonding pads of the semiconductor chip  103  and the inner lead (or the electrode  102 B), or in accordance with a bonding device. 
         [0012]    Referring to  FIG. 14 , the shape, in a plan view, of the fine metal wire  105 A situated in the upper part of the drawing is curved convexly toward the gate  106 , and the shape, in the plan view, of the fine metal wire  105 B situated in the lower part of the drawing is curved convexly away from the gate  106 . Thus, when the resin is injected from the gate  106 , a point of connection of the fine metal wire  105 A with the electrode  102 A and the semiconductor chip  103  is subjected to the action of force pressing the point of connection. There is a small likelihood that the pressing force will cause the fine metal wire  105 A to break at the point of connection. However, the shape, in the plan view, of the fine metal wire  105 B is curved concavely toward the gate  106 , and thus, the action of the resin pressure on the fine metal wire  105 B leads to the action of tensile stress on a point of connection between the fine metal wire  105 B and other members. The point of connection of the fine metal wire  105 B is vulnerable to the tensile stress, and thus, there is a great likelihood that the resin pressure will cause the fine metal wire  105 B to break at the point of connection. 
         [0013]    In addition, there is a trend in portable terminals, for example small-sized equipment such as mobile telephones, toward lightness, thinness, shortness and smallness, and various semiconductor packages as mounted on these are eagerly desired to likewise become thinner. Then, an attempt to suppress a rise in the fine metal wire  105 A in order to achieve a reduction in the thickness of the package can possibly lead to the likelihood that deterioration will occur in mechanical strength at the point of connection between the fine metal wire  105 A and other members, and thus, the above-mentioned breaking of the wire, involved in the resin injection, will manifest itself. The reason is that, if the fine metal wire  105 A is formed into a low loop, the fine metal wire  105 A is plastically deformed in complicated form in the vicinity of the point of connection between the fine metal wire  105 A and other members. 
       SUMMARY OF THE INVENTION 
       [0014]    The present invention has been made in order to solve the foregoing problems. A principal object of the present invention is to provide a semiconductor device and a method of manufacturing the same, which achieve a reduction in the overall thickness by suppressing the rise in the fine metal wire, and also achieve an increase in the reliability of connection at the point of connection between the fine metal wire and other members at the time of the resin sealing. 
         [0015]    A semiconductor device of the present invention comprises: a semiconductor chip; an electrode provided around the semiconductor chip; a fine metal wire that connects a bonding pad on the semiconductor chip and the electrode; and a sealing resin that seals the semiconductor chip, the electrode and the fine metal wire. Here, the sealing resin is injected into a cavity formed by a molding die from one side of the cavity, and the fine metal wire is curved convexly toward an inlet for the injection, as viewed in a plan view. 
         [0016]    Further, a semiconductor device of the present invention comprises: a semiconductor chip; an electrode provided around the semiconductor chip; a fine metal wire that connects a bonding pad on the semiconductor chip and the electrode; and a sealing resin that seals the semiconductor chip, the electrode and the fine metal wire. Here, the fine metal wire is curved as viewed in a plan view, in such a manner that fixedly bonded portions located on both ends of the fine metal wire are pressurized by injection pressure of the sealing resin. 
         [0017]    Furthermore, a semiconductor device of the present invention comprises: a rectangular semiconductor chip; a plurality of bonding pads provided along four side edges of the semiconductor chip; a plurality of electrodes surrounding the semiconductor chip and provided in close proximity to locations corresponding to the bonding pads, respectively; and a sealing resin that seals the semiconductor chip, the electrodes and the fine metal wires. Here, the sealing resin is injected along an extension line of a diagonal line of the semiconductor chip, and each of the fine metal wires is curved convexly against a flow of the sealing resin from an inlet for injection, as viewed in a plan view. 
         [0018]    A method of manufacturing a semiconductor device of the present invention, comprises the steps of: connecting a bonding pad provided on a top surface of a semiconductor chip, to an electrode provided in close proximity to the semiconductor chip, by a fine metal wire; and loading the semiconductor chip, the fine metal wire and the electrode in a cavity of a molding die, and injecting a sealing resin from a gate provided in a side edge of the cavity into the cavity, and thereby sealing the semiconductor chip, the fine metal wire and the electrode with the sealing resin. Here, wherein a shape, in a plan view, of the fine metal wire is curved convexly upstream of a flow of the sealing resin injected from the gate. 
         [0019]      FIG. 3  is a plan view of a fine metal wire  15 A as seen from above the top surface of a package. As can be seen also from vectors shown in this drawing, the fine metal wire  15 A is curved opposite to (i.e., upstream of) the direction (indicated by F 1  to F 3 ) of flow of the resin injected from the gate, and thereby, forces exerted on both ends of the fine metal wire  15 A act as compression rather than tension. Moreover, as shown by a vector diagram, the forces are lessened to form forces F 2   a  and F 3   a  and thereby improve the reliability. 
         [0020]    As otherwise expressed, the fine metal wire is formed in such a manner as to extend in a direction (i.e., the direction from top to bottom of the drawing) crossing (or perpendicular to) the direction of the flow of the resin (flowing horizontally in the direction from left to right), and to curve convexly against the resin flow (indicated by F 1  to F 3 ) (i.e., to curve convexly in the direction from right to left). Thereby, forces exerted on both ends of the fine metal wire act as compression or pressurization, rather than tension, and moreover, as shown by the vector diagram, forces of smaller magnitude than that of originally applied injection pressure (indicated by F 1  to F 3 ) act to thus prevent separation of the fine metal wire. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]      FIG. 1  is a plan view showing a semiconductor device of the present invention. 
           [0022]      FIG. 2  is a cross-sectional view showing the semiconductor device of the present invention. 
           [0023]      FIG. 3  is a view showing the semiconductor device of the present invention, with a fine metal wire  15 A subjected to the action of force involved in resin sealing. 
           [0024]      FIGS. 4A and 4B  are views showing a comparison, illustrating the fine metal wire of the present invention as subjected to the action of force F 1 , and a fine metal wire of a comparative example as subjected to the action of force F 1 , respectively. 
           [0025]      FIGS. 5A ,  5 B and  5 C are a plan view, a cross-sectional view and a cross-sectional view, respectively, showing semiconductor devices of the present invention. 
           [0026]      FIG. 6  is a plan view showing a semiconductor device of the present invention. 
           [0027]      FIG. 7  is a plan view showing a semiconductor device of the present invention. 
           [0028]      FIG. 8  is a cross-sectional view showing a semiconductor device of the present invention. 
           [0029]      FIG. 9  is a plan view showing the semiconductor device of the present invention. 
           [0030]      FIG. 10  is a plan view showing a method of manufacturing a semiconductor device of the present invention. 
           [0031]      FIGS. 11A to 11F  are cross-sectional views showing the method of manufacturing the semiconductor device of the present invention. 
           [0032]      FIGS. 12A to 12E  are cross-sectional views showing the method of manufacturing the semiconductor device of the present invention. 
           [0033]      FIGS. 13A and 13B  are cross-sectional views showing the method of manufacturing the semiconductor device of the present invention. 
           [0034]      FIG. 14  is a plan view showing a background-art semiconductor device. 
           [0035]      FIG. 15  is a cross-sectional view showing the background-art semiconductor device. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0036]    Description will be given below of a semiconductor device according to the present invention. In  FIG. 1  and other drawings, description will be given of a package (or a semiconductor device) having a discrete type transistor embedded therein by way of example; however, it goes without saying that the present invention may be otherwise applied. In short, any one of an IC, an LSI, and a system LSI, or a combination of two or more of these may be embedded in the semiconductor device of the present invention. Further, a BIP type transistor, a power MOS, an IGBT, a GTBT, a BIP type IC or LSI, a MOS type IC or LSI, or furthermore, a BiCMOS type LSI, or the like may be used as a semiconductor chip to be embedded in the semiconductor device. 
       First Embodiment 
       [0037]    In the first embodiment, description will be given, with reference to  FIGS. 1 to 9 , of a configuration of a semiconductor device  10 A and so on, and a sealing method therefor. 
         [0038]    Firstly, description will be given, with reference to  FIGS. 1 and 2 , of the configuration of the semiconductor device  10 A according to the first embodiment, and so on. Incidentally, FIG.  1  is a plan view of the semiconductor device  10 A that forms a rectangular semiconductor package, and  FIG. 2  is a cross-sectional view of the semiconductor device  10 A taken along a fine metal wire  15 B. Further, with reference to these drawings, a manufacturing method will also be described. Accordingly, these drawings also show a cavity  17  and a gate  16  of a molding die for use in resin sealing. 
         [0039]    The semiconductor device  10 A is configured by generally including electrodes  12 A,  12 B and  12 C, a semiconductor chip  13  fixedly bonded to the top surface of the electrode  12 A formed in the shape of an island, a fine metal wire  15 A that connects the semiconductor chip  13  and the electrode  12 C, the fine metal wire  15 B that connects the semiconductor chip  13  and the electrode  12 B, and a sealing resin  11  that integrally seals these components and thereby mechanically supports them. 
         [0040]    In other words, the semiconductor device  10 A is constructed to form what is called a lead frame type package. Specifically, the semiconductor chip  13  is fixedly bonded to the top surface of the island formed of a portion of the electrode  12 A. Then, the electrodes  12 B and  12 C are each formed of an outer lead that forms an exposed portion exposed to the outside from the sealing resin  11 , and an inner lead that forms a coated portion coated with the sealing resin  11 . Further, the fine metal wires  15 B and  15 A are wire-bonded to the top surfaces of the inner lead portions of the electrodes  12 B and  12 C, respectively. 
         [0041]    The semiconductor chip  13  is fixedly bonded to the top surface of an island-shaped region of the electrode  12 A with a solder material or conductive paste such as silver paste in between. Then, the top surface of the semiconductor chip  13  is provided with two bonding pads  14 A and  14 B. Further, an electrode, not shown, is formed also on the underside of the semiconductor chip  13 . A MOS transistor is here used by way of example as the semiconductor chip  13 , and there, the bonding pads  14 A and  14 B serve as a gate electrode and a source electrode, respectively, and the electrode on the underside of the semiconductor chip  13  serves as a drain electrode. 
         [0042]    The electrodes  12 A,  12 B and  12 C are connected to the semiconductor chip  13  and are partially exposed to the outside from the sealing resin  11 . The electrode  12 A is such that the left end thereof, as seen in the drawing, is exposed to the outside, that the right region thereof is formed wider than other regions into the shape of the island, and that the underside of the semiconductor chip  13  is fixedly bonded and electrically connected to the top surface of the island-shaped region. The electrode  12 B is such that the fine metal wire  15 B is connected to the top surface of a left region of the electrode  12 B, and that the right end of the electrode  12 B is exposed to the outside from the sealing resin  11 . As is the case with the electrode  12 B, the electrode  12 C is likewise such that the fine metal wire  15 A is connected to the top surface of a left region of the electrode  12 C, and that the right end of the electrode  12 C is exposed to the outside from the sealing resin  11 . 
         [0043]    Referring to the cross-sectional view of  FIG. 2 , the right island-shaped region of the electrode  12 A is formed thinner than a left region thereof. Specifically, the electrode  12 A is such that the top surface of the right island-shaped region is located below the left area exposed to the outside. Meanwhile, the underside of the right island-shaped region is located above the left area exposed to the outside. The top surface of the island-shaped region of the electrode  12 A is located at low level thereby to enable the lowering of the position of the semiconductor chip  13  and the fine metal wire  15 B fixedly bonded to this region, thus permitting a reduction in the thickness of the semiconductor device  10 A. Incidentally, the sealing resin  11  also extends beneath the island-shaped portion of the electrode  12 A. 
         [0044]    Further, the electrodes  12 B and  12 C, likewise, are each such that the underside of the left region (i.e., the region whose top surface has a connection to the fine metal wire  15 A or the like) is located above the underside of the right area exposed to the outside. Then, the electrodes  12 B and  12 C, likewise, are each such that the sealing resin  11  extends beneath the left region. 
         [0045]    The fine metal wires  15 A and  15 B have the function of providing electrical connections between the bonding pads  14 A and  14 B provided on the top surface of the semiconductor chip  13  and the electrodes  12 B and  12 C. For example, the fine metal wires  15 A and  15 B are the fine wires made of gold, each having a diameter of about 20 μm. A specific configuration of the fine metal wire, as described with reference to  FIG. 2 , is such that the fine metal wire  15 B is ball bonded to the bonding pad of the semiconductor chip  13 , extends upward about 50 μm, is then bent in an L shape, or equivalently, into substantially a 90° angle, extends obliquely downwardly from outside an edge of the semiconductor chip  13  in the neighborhood of one end of the electrode  12 B in order to avoid the edge, and is stitch bonded to the top surface of the electrode  12 B. The height H of a horizontally extending portion of the fine metal wire  15 B above the top surface of the semiconductor chip  13  is about 50 μm. This configuration is the same, as for the fine metal wire  15 A. 
         [0046]    Here, a method other than ball bonding may be used as a method for forming the fine metal wire  15 B, and for example, wedge bonding may be used to form the fine metal wire  15 B. 
         [0047]    The sealing resin  11  is injection-molded by using the molding die, and specifically, transfer molding using a thermosetting resin or injection molding using a thermoplastic resin is used to form the sealing resin  11 . The side of the sealing resin  11  is formed slightly obliquely, allowing for removal from the molding die. However, generally, the outer shape of the package made of the sealing resin  11  is a cube or a rectangular parallelepiped. In other words, a top, a bottom, and four sides that link the top and the bottom form the outer shape formed of the sealing resin  11 . 
         [0048]    A feature of the present invention is that the shapes, in a plan view, of the fine metal wires  15 A and  15 B are curved convexly upstream of the flow of the injected sealing resin  11 . 
         [0049]    Specifically, referring to  FIG. 2 , a method for forming the sealing resin  11  is as follows. First, the electrode  12 A and so on, the semiconductor chip  13 , and the fine metal wire  15 B and so on are loaded in the cavity  17  of a die  18  formed of a top die  19  and a bottom die  20 . Then, the sealing resin  11  in liquid form is injected from the gate  16  (see  FIG. 1 ) provided in the die  18  into the cavity  17 . Finally, the sealing resin  11  is thermally cured as needed, and then, the sealing resin  11  is unloaded from the die  18 . Therefore, the sealing resin  11  in liquid form is injected from the gate  16 , and thus, at the time of the resin sealing, a downward pressure from above the sheet as seen in the drawing acts on the fine metal wires  15 A and  15 B. Then, a deformation, a break or the like can possibly occur in the fine metal wires  15 A and  15 B unless measures against this stress are taken. 
         [0050]    In this embodiment, the shapes, in the plan view, of the fine metal wires  15 A and  15 B are devised thereby to prevent their deformation or breaking. Specifically, referring to  FIG. 1 , the two fine metal wires  15 A and  15 B are used in the semiconductor device  10 A, and the shapes, in the plan view, of both the fine metal wires  15 A and  15 B are looped so as to curve convexly in upward directions. In other words, the fine metal wires  15 A and  15 B are looped convexly upstream of (i.e., opposite to) the flow of the sealing resin  11  in liquid form injected from the gate  16 . The fine metal wires  15 A and  15 B have this configuration, and thereby, even if pressure produced by the sealing resin  11  injected from the gate  16  acts, forces acting on points of connection between the fine metal wires  15 A and  15 B and other members are pressing forces (or compressive forces), and thus, the breaking at the points of connection is suppressed. Further, the above-mentioned curved configuration also lessens the force acting on the point of connection thereby to prevent the fine metal wire  15 A from becoming broken or deformed. Details of this will be described later with reference to  FIG. 3 . 
         [0051]    Here, in other words, the curved configuration of the fine metal wire  15 A or the like, which is a point of the present invention, is such that the fine metal wire  15 A is curved convexly toward the gate  16  from which the sealing resin  11  is injected. Further, the shape, in the plan view, of the fine metal wire  15 A or the like is such a curved shape that pressurizing force acts on fixedly bonded portions  21  and  22  (see  FIG. 3 ) (that is, tensile force does not acts thereon), even if the pressure of the injected sealing resin  11  acts. 
         [0052]    A further feature of the present invention is that the above-mentioned shape in the plan view is applied to a fine metal wire with a low loop. Specifically, referring to  FIG. 2 , the configuration of the fine metal wire  15 B is not an arched configuration, but a configuration such that most part of the fine metal wire  15 B extends parallel to the top surface of the semiconductor chip  13 . Specifically, referring to this drawing, the fine metal wire  15 B has the fixedly bonded portion  21  at the left end, and has the fixedly bonded portion  22  at the right end. Then, a portion (i.e., an intermediate portion) of the fine metal wire  15 B, exclusive of the vicinities of both the fixedly bonded portions, extends parallel to the top surface of the electrodes  12 A and  12 B. This configuration is implemented thereby to lower the position of the topmost portion of the fine metal wire  15 B and thus reduce the thickness of the overall semiconductor device  10 A. 
         [0053]    However, the implementation of this configuration leads to deterioration of mechanical strength at the point of connection (i.e., the fixedly bonded portion  21 ) between the bonding pad of the semiconductor chip  13  and the fine metal wire  15 B. Therefore, if the pressure from the sealing resin  11  acts on the fine metal wire  15 B with the low loop, a break can possibly occur at the point of connection (i.e., the fixedly bonded portion  21 ) between the fine metal wire  15 B and the semiconductor chip  13 . Therefore, in the first embodiment, as mentioned above, the shape, in the plan view, of the fine metal wire  15 B is such that the fine metal wire  15 B is curved convexly upstream of the flow of the sealing resin  11  injected. Thereby, tensile stress does not act on the point of connection between the semiconductor chip  13  and the fine metal wire  15 B. Thus, this point of connection is subjected to the action of pressing stress and tends to be resistant to the pressing stress rather than the tensile stress, and thus, a break at the point of connection is prevented. Details of a method for forming the fine metal wire  15 B with the low loop will be described later. 
         [0054]    Further, in this embodiment, in order to improve heat radiation properties, the sealing resin  11  may be made of a resin material containing mixed therein an inorganic filler such as silica. In this instance, the sealing resin  11  in liquid form has a high viscosity, and thus, in a process for the resin sealing, the force of the injected sealing resin  11  acting on the fine metal wire  15 A or the like becomes large. However, in the first embodiment, as mentioned above, the fine metal wire  15 A or the like is curved upstream of the flow of the sealing resin  11  injected, and thus, the breaking of the fine metal wire  15 A or the like is suppressed. 
         [0055]    Stress acting on the fine metal wire  15 A will be specifically described with reference to  FIGS. 3 and 4 . In  FIGS. 3 and 4 , the fine metal wire  15 A extends in the direction from top to bottom, the upper end is the fixedly bonded portion  21  connected to the semiconductor chip (not shown), and the lower end is the fixedly bonded portion  22  connected to the top surface of the electrode. 
         [0056]    Referring to  FIG. 3 , the magnitude and direction of pressure produced by the sealing resin is indicated by the arrows designated by F 1  to F 3 . Here, pressure acting on the vicinity of a central portion of the fine metal wire  15 A is indicated by F 1 , pressure acting on the vicinity of the fixedly bonded portion  21  on the upper end is indicated by F 2 , and pressure acting on the vicinity of the fixedly bonded portion  22  on the lower end is indicated by F 3 . Then, F 1  to F 3  act in the direction from left to right in the drawing. This direction is the same as the flowing direction of the sealing resin in liquid form. Further, the magnitudes of F 1  to F 3  are substantially the same. 
         [0057]    The shape, in the plan view, of the fine metal wire  15 A is such that the fine metal wire  15 A is curved, while projecting out in a direction opposite to the direction of action of F 1  to F 3  (that is, leftward as seen in the drawing). With this configuration, forces acting on the fixedly bonded portions  21  and  22  are compressive forces, and also, the forces acting on the fixedly bonded portions  21  and  22  in themselves can be lessened thereby to prevent the separation of the fine metal wire  15 A from the fixedly bonded portions  21  and  22 . 
         [0058]    Specifically, first, F 1  acts on the central portion of the fine metal wire  15 A and causes slight elastic deformation in the fine metal wire  15 A. However, most of F 1  is accommodated by the fine metal wire  15 A becoming slightly deformed, and thus, the fine metal wire  15 A does not undergo great plastic deformation, so that F 1  does not have an adverse influence on the fine metal wire  15 A. 
         [0059]    F 2  acting on the fine metal wire  15 A in the vicinity of the fixedly bonded portion  21  is resolved into a force F 2   a  parallel to a tangent to the curved fine metal wire  15 A, and a force F 2   b  perpendicular to the tangential direction. The force acting on the fixedly bonded portion  21  is the resolved force F 2   a , and the magnitude of F 2   a  is small as compared to the original force F 2 , and thus, the separation of the fine metal wire  15 A from the fixedly bonded portion  21  is prevented. For example, if the direction of action of F 2  and the tangent to the fine metal wire  15 A intersect at an angle of 45 degrees, the magnitude of F 2   a  is about 0.7 time that of F 2 . 
         [0060]    Further, as mentioned above, if the fine metal wire  15 A has the low loop, the shape of the fine metal wire  15 A in the vicinity of the fixedly bonded portion  21  becomes complicated and thus the breaking of the wire can possibly occur; however, the fine metal wire  15 A is curved in a specific direction thereby prevent the breaking of the wire. 
         [0061]    On the other hand, F 3  acting on the vicinity of the fixedly bonded portion  22  on the lower end can also be resolved in the same manner as described above. Specifically, F 3  is resolved into a force F 3   a  parallel to a tangent to the fine metal wire  15 A in the vicinity of the fixedly bonded portion  22 , and a force F 3   b  perpendicular to the tangent. Then, compressive force acting on the fixedly bonded portion  22  of the fine metal wire  15 A is F 3   a  that is smaller than F 3 , and thus, the breaking of the wire in the fixedly bonded portion  22  is prevented. 
         [0062]    A further feature of this embodiment will be described with reference to  FIG. 4 . FIG.  4 A shows the shape of the fine metal wire  15 A of the first embodiment, and  FIG. 4B  shows the fine metal wire  15 A as formed in a straight line. 
         [0063]    Referring to  FIG. 4A , the pressure F 1  involved in the resin sealing acts on the fine metal wire  15 A from the left side in the drawing. The action of the force F 1  leads to deformation in the fine metal wire  15 A as shown by dotted lines, and hence to the action of compressive forces on the fixedly bonded portions  21  and  22 . However, as mentioned above, the fine metal wire  15 A is curved convexly leftward, and thus, forces resolved along the tangential direction of the fine metal wire  15 A act on the fixedly bonded portions  21  and  22 . Thus, the breaking of the fine metal wire  15 A in the vicinity of the fixedly bonded portions  21  and  22  is suppressed. Further, the action of the force F 1  causes the deformation in the fine metal wire  15 A as shown by the dotted lines; however, this deformation is elastic deformation, and thus, when the force F 1  is released, the fine metal wire  15 A is restored to its original shape. 
         [0064]    A comparative example will be described with reference to  FIG. 4B . Here, discussion is made of an instance where the shape, in the plan view, of the fine metal wire  15 A is in the form of a straight line rather than a curved line. When the force F 1  acts on the fine metal wire  15 A formed in a straight line, the fine metal wire  15 A is deformed into a curved form projecting rightward (as shown by dotted lines). When the fine metal wire  15 A is deformed in this manner, the force F 1  exerted on the fixedly bonded portion  21  is resolved into a force F 1 α parallel to the tangent to the deformed fine metal wire  15 A, and a force F 1 β perpendicular to the tangent. Then, the force F 1 α is tensile force, and the action of the tensile force F 1 α on the fine metal wire  15 A leads to the likelihood that the breaking of the fine metal wire  15 A will occur in the vicinity of the fixedly bonded portion  21 . The same goes for the fine metal wire  15 A in the vicinity of the fixedly bonded portion  22 . 
         [0065]    From the above discussion, it has been shown that, for the shape, in the plan view, of the fine metal wire  15 A, a form such that the fine metal wire  15 A is curved convexly upstream of the flow of the sealing resin  11  is preferable to the straight-line form, allowing for the pressure of the sealing resin  11  being injected. 
         [0066]    Description will be given, with reference to  FIGS. 5A to 5C , of a configuration of a semiconductor device  10 B of another form.  FIG. 5A  is a plan view of the semiconductor device  10 B as seen from above,  FIG. 5B  is a cross-sectional view thereof, and  FIG. 5C  is a cross-sectional view of a semiconductor device  10 C of another form. 
         [0067]    A basic configuration of the semiconductor device  10 B shown in  FIGS. 5A and 5B  is the same as that of the above-mentioned semiconductor device  10 A, and a difference lies in the configuration of the electrode  12 A or the like. In the semiconductor device  10 B shown here, the electrodes  12 A,  12 B and  12 C are disposed on the top surface of a circuit board  23  made of an insulating material such as glass epoxy, and the semiconductor chip  13  is disposed on the top surface of the electrode  12 A. Then, two bonding pads formed on the top surface of the semiconductor chip  13  are connected respectively via the fine metal wires  15 A and  15 B to the electrodes  12 C and  12 B. 
         [0068]    Also in the semiconductor device  10 B, the shapes, in the plan view, of the fine metal wires  15 A and  15 B are curved convexly upstream of the flow of the sealing resin  11  being injected from the gate  16 . 
         [0069]    Referring to  FIG. 5B , here, the electrodes  12 A,  12 B and  12 C (not shown) are formed on the top surface of the circuit board  23 . Then, the circuit board  23  is provided with a conductive material (or through connections) such as copper, formed through the circuit board  23  in the direction of thickness thereof. The electrodes  12 A,  12 B and  12 C provided on the top surface of the circuit board  23  are connected respectively via the through connections to underside electrodes  33 A,  33 B and  33 C (not shown) provided and exposed on the underside of the circuit board  23 . An external connection electrode made of a conductive adhesive material such as solder is welded to the underside electrode  33 A or the like, and the external connection electrode is used for surface mounting of the semiconductor device  10 B on the top surface of a packaging board or the like. 
         [0070]    Here, besides the above-mentioned single-layer glass epoxy substrate, various materials may be used as the circuit board  23  of the semiconductor device  10 B. For example, a printed board made of a resin substrate whose surface is provided with a wiring layer of a predetermined configuration, a flexible sheet made of a flexible resin sheet provided with a predetermined wiring layer, a metal substrate made of metal whose top surface is coated with an insulating layer made of an insulating material such as a resin, a substrate made of an inorganic material such as ceramics, or the like may be used as the circuit board  23 . Here, if a wiring layer is provided on the top surface of the circuit board  23 , a multilayer wiring structure having two or more wiring layers stacked one on top of another with an interlayer dielectric in between may be used. 
         [0071]    Description will be given, with reference to  FIG. 5C , of a configuration of the semiconductor device  10 C of another form. A basic configuration of the semiconductor device  10 C is the same as that of the above-mentioned semiconductor device  10 B, and a difference lies in that the electrode  12 A or the like is partially exposed to the outside from the sealing resin  11 . Description will be given below, centering on this point of difference. 
         [0072]    The semiconductor device  10 C is configured by including the electrodes  12 A,  12 B and  12 C (not shown), the semiconductor chip  13  fixedly bonded to the top surface of the electrode  12 A, the fine metal wire  15 B that provides an electrical connection between the semiconductor chip  13  and the electrode  12 B, and the sealing resin  11  that seals these components. Then, the electrode  12 A or the like is coated at the top and side with the sealing resin  11  and is exposed, at the underside, to the outside from the sealing resin  11 . In addition, the underside of the electrode  12 A or the like and the underside of the sealing resin  11 , exclusive of an area where the external connection electrode such as solder is welded to the electrode  12 A or the like, are coated with a resist  25  made of a resin. 
         [0073]    Description will be given, with reference to  FIG. 6 , of a configuration of a semiconductor device  10 D of another form. A basic configuration of the semiconductor device  10 D is the same as that of the above-mentioned semiconductor device  10 B or the like, and differences lie in bonding pads provided on the top surface of the semiconductor chip  13 , and the configuration of electrodes  12 . 
         [0074]    The points of difference, as described specifically, are as follows. Firstly, the top surface of the semiconductor chip  13  is provided with many bonding pads. Here, multiple bonding pads  14 A are disposed along an upper side edge of the semiconductor chip  13  as seen in the drawing, and multiple bonding pads  14 B are disposed along a lower side edge thereof. Then, many electrodes  12  are provided in close proximity to the semiconductor chip  13 . Specifically, as seen in the drawing, multiple electrodes  12 A are provided above the semiconductor chip  13 , and multiple electrodes  12 B are provided under the semiconductor chip  13 . In addition, the bonding pads  14 A provided along the upper side edge of the semiconductor chip  13  are connected respectively via the fine metal wires  15 A to the electrodes  12 A. Likewise, the bonding pads  14 B provided along the lower side edge of the semiconductor chip  13  are connected respectively via the fine metal wires  15 B to the electrodes  12 B. 
         [0075]    Here, the shapes, in the plan view, of the fine metal wires  15 A and  15 B are curved convexly upstream of the flow of the sealing resin being injected from the gate  16  into the cavity  17 . Referring to the drawing, the shapes, in plan view, of all fine metal wires  15 A and  15 B are curved convexly rightward and curved convexly upstream of flows S 1  and S 2  of the sealing resin being injected from the gate  16 . As mentioned above, this enables the prevention of the deformation and breaking of the fine metal wire  15 A by the pressure of the sealing resin  11  being injected. 
         [0076]    Specifically, when, in a molding process, the sealing resin  11  in liquid form is injected from the gate  16  into the cavity  17 , the injected sealing resin  11  flows preferentially between the semiconductor chip  13  and the electrodes  12 A and  12 B. Here, the flow of the sealing resin  11  flowing preferentially between the semiconductor chip  13  and the electrodes  12 A is shown by a solid line indicated by  51 , and the flow of the sealing resin  11  flowing preferentially between the semiconductor chip  13  and the electrodes  12 B is shown by a solid line indicated by S 2 . Here, the fine metal wires  15 A and  15 B alone are present in the direction of thickness in regions between the semiconductor chip  13  and the electrodes  12 A and  12 B, and thus, these regions are environment in which the sealing resin  11  is flowable as compared to other areas. 
         [0077]    When the sealing resin  11  is injected along S 1  and S 2 , pressure by the sealing resin  11  acts on the fine metal wires  15 A and  15 B; however, also in this case, the shapes, in the plan view, of the fine metal wires  15 A and  15 B are curved convexly against the flow of the sealing resin  11 , thereby preventing damage to the fine metal wires  15 A and  15 B by this pressure. This mechanism is as mentioned above. 
         [0078]    Here, a configuration such as is shown in  FIG. 5B  or a configuration such as is shown in  FIG. 5C  may be used as a cross-sectional configuration of the semiconductor device  10 D. Further, a configuration such that the underside of the semiconductor chip is exposed to the outside from the sealing resin  11  may be used. 
         [0079]    Description will be given, with reference to  FIG. 7 , of a configuration of a semiconductor device  10 E of another form. A basic configuration of the semiconductor device  10 E is the same as that of the above-mentioned semiconductor device  10 D, and a difference lies in that the electrodes  12 A and the like are provided so as to surround the semiconductor chip  13  from four directions. 
         [0080]    Specifically, the top surface of the semiconductor chip  13  is provided with many bonding pads  14  along four side edges thereof, and electrodes are disposed in locations corresponding to the bonding pads, respectively. Specifically, multiple electrodes  12 A,  12 B,  12 C and  12 D are disposed along the upper side edge, right side edge, lower side edge and left side edge, respectively, of the semiconductor chip  13 , as seen in the drawing. Then, the electrodes  12 A,  12 B,  12 C and  12 D disposed so as to surround the semiconductor chip  13  from four directions are connected respectively via the fine metal wires  15 A,  15 B,  15 C and  15 D to the bonding pads  14  on the top surface of the semiconductor chip  13 . 
         [0081]    Also in the semiconductor device  10 E, the shape, in the plan view, of the fine metal wires  15 A and the like are curved convexly upstream of the flow of the sealing resin  11  being injected from the gate. Specifically, first, the gate  16  provided in the cavity  17  of the molding die lies on an extension line  34  of a diagonal line that links corners of the semiconductor chip  13  placed in the cavity  17 . Here, the extension line  34  is shown by a dash-double dot line, and the gate  16  is provided in a location such that the gate  16  overlaps the extension line  34 . Further, here, an air vent  36  is likewise provided in a location such that the air vent  36  overlaps the extension line  34 . 
         [0082]    When the sealing resin  11  in liquid form (or in semisolid form) is injected from the gate  16  into the cavity  17  of the above-mentioned configuration, the injected sealing resin  11  first moves toward the corner of the semiconductor chip  13 . In the drawing, this flow is indicated by S. Then, the sealing resin  11  is divided into two branches in the vicinity of the corner of the semiconductor chip  13 . One of the branches is the flow of the sealing resin  11  along a space between the upper side edge of the semiconductor chip  13  and the electrodes  12 A, as seen in the drawing (i.e., the flow  51 ). The other branch is the flow of the sealing resin  11  along a space between the right side edge of the semiconductor chip  13  and the electrodes  12 B, as seen in the drawing (i.e., the flow S 2 ). The reason why the sealing resin  11  flows preferentially between the semiconductor chip  13  and the electrodes  12 A and the like is as mentioned above. 
         [0083]    The flow S 1  is the flow of the sealing resin  11  starting at the upper right end of the semiconductor chip  13  and flowing along the upper side edge to the lower left end thereof. Specifically, the flow S 1  is such that the sealing resin  11  passes between the upper side edge of the semiconductor chip  13  and the electrodes  12 A and then passes between the left side edge of the semiconductor chip  13  and the electrodes  12 D. 
         [0084]    On the other hand, the flow S 2  is the same as the flow S 1  in the starting point and endpoint but is different in route. Specifically, the flow S 2  is such that the sealing resin  11  flows between the right side edge of the semiconductor chip  13  and the electrodes  12 B and then flows along a space between the lower side edge of the semiconductor chip  13  and the electrodes  12 C. 
         [0085]    Then, the flows S 1  and S 2  are combined into the flow S in the vicinity of the lower left end of the semiconductor chip  13 . In addition, as the sealing resin  11  is injected from the gate  16  into the cavity  17 , air in the cavity  17  is released to the outside through the air vent  36  by an equivalent amount to the injected sealing resin  11 . 
         [0086]    Then, the shapes, in the plan view, of the fine metal wires  15 A and the like are curved convexly upstream of the above-mentioned flow of the sealing resin  11 . Specifically, the fine metal wires  15 A provided on the upper side edge of the semiconductor chip  13  are curved convexly rightward as seen in the drawing. Then, the fine metal wires  15 B provided on the right side edge of the semiconductor chip  13  are curved convexly upward. In addition, the fine metal wires  15 C provided on the lower side edge of the semiconductor chip  13  are curved convexly rightward. Further, the fine metal wires  15 D provided on the left side edge of the semiconductor chip  13  are curved convexly upward. 
         [0087]    With the above-mentioned configuration, the shapes, in the plan view, of all fine metal wires  15 A and the like having connections to the bonding pads  14  can be curved convexly upstream of the flows of the sealing resin  11 , even if the top surface of the semiconductor chip  13  is provided with the bonding pads  14  along the four side edges thereof. This enables the prevention of the breaking of the fine metal wires  15 A and the like by the pressure of the sealing resin  11  being injected. 
         [0088]    Description will now be given, with reference to  FIGS. 8 and 9 , of a configuration of a semiconductor device  10 F of another form.  FIG. 8  is a cross-sectional view of the semiconductor device  10 F, and  FIG. 9  is a plan view of the semiconductor device  10 F as being sealed with the resin. 
         [0089]    Referring to  FIG. 8 , a basic configuration of the semiconductor device  10 F is the same as that of the above-mentioned semiconductor device  10 E, and a difference lies in that the semiconductor device  10 F is of a lead frame type. 
         [0090]    The semiconductor device  10 F includes an island  26  and a lead  27 , and the semiconductor chip  13  is fixedly bonded to the top surface of the island  26 . Then, a bonding pad provided on the top surface of the semiconductor chip  13  is connected via a fine metal wire  15  to the top surface of the lead  27 . Further, the sealing resin  11  is formed so as to coat partially the island  26 , the semiconductor chip  13 , the fine metal wire  15  and the lead  27 . In addition, a portion of the lead  27  exposed to the outside is bent downward at a right angle. 
         [0091]    Description will be given, with reference to  FIG. 9 , of a process for sealing the semiconductor device  10 F of the above-mentioned configuration. Here, the above-mentioned lead  27  and island  26  are supplied in the form of a lead frame  28  formed of the lead  27  and the island  26  integrally linked together in plate form. Specifically, in a unit  32  as an element unit of semiconductor device, the island  26  of a rectangular shape is disposed in the center of the unit  32 , and the leads  27  extending radially outwardly are provided around the island  26 . In addition, each of the leads  27  is formed of an inner lead  29  sealed with the sealing resin  11 , and an outer lead  30  exposed to the outside from the sealing resin  11 , and the leads  27  are linked together by a tie bar  31 . Meanwhile, four corners of the island  26  are mechanically held by suspension leads extending in four directions. 
         [0092]    A die such as is shown in  FIG. 2  is used for a process for subjecting the lead frame  28  of the above-mentioned configuration to the resin sealing. Then, the semiconductor chip  13  is fixedly bonded in advance to the top surface of the island  26 , and the bonding pads formed on the top surface of the semiconductor chip  13  are connected via the fine metal wires  15 A and the like to the leads  27 . Here, the bonding pads provided along the upper side edge, right side edge, lower side edge and left side edge, of the semiconductor chip  13  are connected respectively via the fine metal wires  15 A,  15 B,  15 C and  15 D and the like to the leads  27 . The shapes, in the plan view, of the fine metal wires  15 A and the like are as mentioned above. 
         [0093]    In  FIG. 9 , the side edges of the cavity  17  of the molding die are shown by dash-dot lines. Further, the flow of the sealing resin is shown by thick lines. Also in this instance, the flow S of the sealing resin injected from the gate  16  is divided into the flows S 1  and S 2  within the cavity  17 , and the flows  51  and S 2  are recombined into the flow S in the vicinity of the air vent  36 . Details of this are the same as those for the above-mentioned semiconductor device  10 E. Then, the shapes, in the plan view, of the fine metal wires  15 A and the like are the same as those in the above-mentioned semiconductor device  10 E, and the fine metal wires  15 A and the like are curved convexly upstream of the flow of the sealing resin  11 . Specifically, as seen in the drawing, the fine metal wires  15 A are curved convexly rightward, the fine metal wires  15 B are curved convexly upward, the fine metal wires  15 C are curved convexly rightward, and the fine metal wires  15 D are curved convexly upward. This enables the prevention of the breaking of the fine metal wires  15 A and the like during the resin sealing. 
       Second Embodiment 
       [0094]    In this embodiment, description will be given, with reference to  FIGS. 10 to 13 , of a method of manufacturing the semiconductor devices  10 A to  10 F of the above-mentioned configuration. Incidentally, since the process for the resin sealing has been described in detail with reference to the first embodiment, description will be given below mainly of processes other than the resin sealing process. 
         [0095]    First, referring to  FIG. 10 , the lead frame  28  is prepared in which the semiconductor chip is placed on each unit  32 . Here, a pressing process or an etching process is used for preparation of the lead frame  28  provided with many units  32  of a predetermined configuration. Then, the semiconductor chip is mounted on each unit  32 . Details of each unit  32  are as shown for example in  FIGS. 1 and 2 . 
         [0096]    Then, referring to  FIGS. 11 to 13 , the fine metal wires  15  are used to provide connections between the bonding pads  14  of the semiconductor chip  13  and the top surfaces of the electrodes (or the leads). In this embodiment, the fine metal wire  15  is not in loop form but in a form such that the fine metal wire  15  is parallel to the semiconductor chip  13  and the top surface of the electrode (or the lead). This enables the lowering of the position of the topmost portion of the fine metal wire  15 , and thus correspondingly reduction of the thickness of the semiconductor device manufactured. 
         [0097]    First, as shown in  FIG. 11A , a tip of the fine metal wire  15  (of 20 μm in diameter) inserted through a capillary tool  40  is melted by arc discharge or the like, thereby to form an Au ball  35  of 50 to 80 μm in diameter, utilizing surface tension, as shown in  FIG. 11B . 
         [0098]    Then, the capillary tool  40  is moved to press the Au ball  35  against the bonding pad  14 , and, in this state, bonding energy (such as ultrasonic vibration, load, or heat) is applied thereby to join the fine metal wire  15  to the bonding pad  14  (See  FIG. 11C ). 
         [0099]    Then, the capillary tool  40  is moved upward (see  FIG. 11D ), and thereafter, the capillary tool  40  is moved downward in an oblique direction (i.e., at an angle of about 45° with respect to a vertical direction) so as to move away from the bonding pad  14  (see  FIG. 11E ), and the capillary tool  40  is pressed again against the bonding pad  14  (see  FIG. 11F ). Surroundings of the bonding pad  14  at this time are shown in  FIG. 11F . As shown in an enlarged view of  FIG. 11F , by the above-mentioned movement of the capillary tool  40 , a joint portion is pressed against a head (or a lower end) of the capillary tool  40  thereby to form a thin portion  42 . This creates a situation where the fine metal wire  15  is likely to break at a point of joint; however, according to the present invention, the shape, in the plan view, of the fine metal wire is in the above-mentioned curved form thereby to prevent the breaking of the fine metal wire  15  involved in the resin sealing process. Then, the capillary tool  40  is moved upward again (see  FIG. 12A ), and thereafter, the capillary tool  40  is moved downward in an oblique direction (i.e., at an angle of about 45° with respect to the vertical direction) opposite to the above-mentioned oblique direction shown in  FIG. 11E  so as to move away from the bonding pad  14  (see  FIG. 12B ), and the capillary tool  40  is pressed again against the bonding pad  14 . Surroundings of the bonding pad  14  at this time are shown in  FIG. 12C . As shown in an enlarged view of  FIG. 12C , by the above-mentioned movement of the capillary tool  40 , a lump of melted Au stacked in an S shape is formed on the bonding pad  14 , and thereby, the fine metal wire  15  is in a state such that the fine metal wire  15  is easily pulled out horizontally (that is, the fine metal wire  15  is unlikely to be broken). 
         [0100]    By the above-mentioned operation, the lump of melted Au is formed, but the fine metal wire  15  therearound is repeatedly plastically deformed and thus undergoes deterioration of mechanical strength. According to the present invention, the shape, in the plan view, of the fine metal wire  15  is in the curved form thereby to suppress the breaking of the fine metal wire  15  having deteriorated mechanical strength, during the resin sealing. 
         [0101]    Then, the capillary tool  40  is moved slightly upward again (see  FIG. 12D ), and the capillary tool  40  is moved from this position in such a manner that the trajectory thereof forms a curve, thereby to pull out the fine metal wire  15  toward the electrode  12 B (see  FIGS. 12E and 13A ). Then, the head of the capillary tool  40  is put on the top surface of the electrode  12 B, the fine metal wire  15  is stitch-bonded here (see  FIG. 13A ), and a wire clamp  41  is closed to cut off the fine metal wire  15  (see  FIG. 13B ). At this time, the capillary tool  40  is moved so that the shape, in the plan view, of the fine metal wire  15  is curved convexly opposite to the direction in which the sealing resin is to be injected later. 
         [0102]    Incidentally, the slight upward movement of a bonding wire in  FIG. 12D  is for the purpose of preventing the fine metal wire  15  from coming into contact with the semiconductor chip  13 . 
         [0103]    The use of the above-described method for wire bonding enables the fine metal wire  15  to be pulled out from the bonding pad  14  substantially horizontally (i.e., in a direction parallel to the top surface of the semiconductor chip), without producing high tension in the fine metal wire  15  and thus without breaking the fine metal wire  15 . This makes it possible to suppress an upward rise in the fine metal wire  15 , and correspondingly to suppress the thickness of a product. 
         [0104]    In the above, the fine wire (made of gold, having a diameter of about 20 μm) can be used as the fine metal wire  15  thereby to suppress load on the electrode  12 B. In addition, the use of the fine wire makes it possible to suppress strain or stress appearing on a metal surface, and thus to prevent excessive deformation in the fine metal wire  15 . 
         [0105]    The above-mentioned wire bonding process is performed for all units  32  shown in  FIG. 10 . 
         [0106]    After the completion of the above-mentioned wire bonding process, the resin sealing is performed using transfer molding. Details of this process are as mentioned above with reference to  FIG. 2  and others. Specifically, first, the lead frame  28  is loaded in the die of a molding device, and thereby, the units  32  provided in the lead frame  28  are individually placed in the cavities  17 . Then, the sealing resin is injected from a pot provided in the molding die, into the cavities  17 . Specifically, a resin lump placed in the pot is heated and becomes fluidic, is then pushed out by a plunger, is injected through a runner from the gate into the cavity, and is cooled to form a package. At this time, as mentioned above, the shape, in the plan view, of the fine metal wire is curved convexly upstream of the flow of the sealing resin being injected, and thus, the danger of the breaking of the wire or the like involved in the resin sealing is suppressed. At this time, the temperature of the die is set in the neighborhood of 180° C., for example. 
         [0107]    After the completion of the above-mentioned process, the semiconductor device is completed through a deflashing process, a process for plating for exterior, a process for separating the units  32  from the lead frame  28 , a process for screening the semiconductor devices according to electrical characteristics, a process for printing electrical characteristics, a company name, or the like on an outer surface of the sealing resin, a packing process, and so on. 
         [0108]    The above description of the embodiments is for the purpose of facilitating the understanding of the present invention, and is not intended to limit the scope of the present invention. Of course, it is to be understood that various changes and modifications can be made without departing from the scope of the present invention, and equivalence may be included in the present invention. 
         [0109]    For example, all fine metal wires may be curved convexly upstream of the flow of the sealing resin; alternatively, some fine metal wires may be curved concavely. If some fine metal wires are curved convexly, the fine wire having a diameter of about 20 μm may be curved convexly, and a thick wire (having a diameter of about 100 μm, for example) thicker than the fine wire may be in other forms (in a straight form or in a form curved concavely against the flow).