Patent Publication Number: US-10312603-B2

Title: Fixing structure and fixing method

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from Japanese patent application No. 2015-206109, filed on Oct. 20, 2015, the disclosure of which is incorporated herein in its entirety by reference. Additionally, this application is a divisional application of U.S. patent application Ser. No. 15/265,898, filed on Sep. 15, 2016, the entire contents of which are hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a fixing structure and a fixing method. 
     2. Description of Related Art 
     Japanese Unexamined Patent Application Publication No. 2003-204149 discloses a technique for soldering lead terminals  101  of an FPIC (Flat Package Integrated Circuit)  100  to a wiring electrode  103  of a printed board  102  as shown in  FIG. 37  of the present application. Specifically, a laser beam  106  output from a laser oscillator  105  is irradiated onto each lead terminal  101 , so that a solder layer  104  is melted and spread out and the lead terminal  101  is soldered to the wiring electrode  103 . 
     In particular, in the fields of FPIC and connectors, when a laser beam is used to fix a terminal to a conductive pattern formed on a substrate, a reduction in laser beam irradiation time per terminal is directly linked to an improvement in productivity. 
     However, in the structure disclosed in Japanese Unexamined Patent Application Publication No. 2003-204149 described above, it has been difficult to further reduce the laser beam irradiation time per terminal. This is because in the structure disclosed in Japanese Unexamined Patent Application Publication No. 2003-204149, each lead terminal  101  is fixed to the wiring electrode  103  by wetting phenomena of the melted solder layer  104 . In this case, it is necessary to continuously heat the lead terminals  101  by a laser beam until the lead terminals  101  become wet with the solder layer  104 . A time required until the lead terminals  101  become wet with the solder layer  104  is called a zero cross time. The zero cross time is about several hundred msec. 
     Accordingly, an object of the present invention is to provide a technique for reducing a laser beam irradiation time per terminal when a terminal is fixed to an object to be fixed with a brazing filler metal. 
     SUMMARY OF THE INVENTION 
     A first exemplary aspect of the present invention is a fixing method for fixing a terminal to an object to be fixed with a brazing filler metal disposed therebetween, the fixing method including: a first step of disposing the brazing filler metal on the object to be fixed; a second step of bringing the terminal into contact with the brazing filler metal; and a third step of forming a penetrating hole in the terminal by irradiating a laser beam onto the terminal. In the third step, the laser beam is irradiated onto the terminal in such a manner that the penetrating hole is filled with the brazing filler metal melted by the irradiation of the laser beam. 
     A second exemplary aspect of the present invention is a fixing structure including: a substrate; a conductive pattern formed on the substrate; an adhesive layer formed of a brazing filler metal; and a terminal, the terminal being fixed to the conductive pattern by the adhesive layer. A penetrating hole is formed in the terminal, the penetrating hole being gradually widened in a direction apart from the substrate. The penetrating hole is filled with the brazing filler metal. 
     A third aspect of the present invention is a fixing structure including: a wire including a conductor; a brazing filler metal wetting the conductor; and a terminal, the terminal being fixed to the conductor by the brazing filler metal. A penetrating hole is formed in the terminal, the penetrating hole being gradually widened in a direction apart from a central axis of the conductor. The penetrating hole is filled with the brazing filler metal. 
     According to the above-mentioned aspects of the present invention, the brazing filler metal enters the penetrating hole, thereby allowing the terminal to be fixed to the conductive pattern with the brazing filler metal disposed therebetween. Further, the fixation between the terminal and the brazing filler metal is not due to wetting phenomena. Accordingly, the laser beam irradiation time per terminal can be reduced as compared with a case where the fixation between the terminal and the brazing filler metal is due to wetting phenomena. Furthermore, according to the above-mentioned aspects of the present invention, since the brazing filler metal reaches the vicinity of the upper end of the penetrating hole, whether the terminal and the brazing filler metal are fixed to each other can be confirmed when a laser beam irradiation surface of the terminal is viewed from above. 
     The above and other objects, features and advantages of the present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not to be considered as limiting the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a circuit module (first exemplary embodiment); 
         FIG. 2  is an enlarged view of a portion “A” shown in  FIG. 1  (first exemplary embodiment); 
         FIG. 3  is a partially cutaway perspective view of a fixing structure (first exemplary embodiment); 
         FIG. 4  is a sectional view of the fixing structure (first exemplary embodiment); 
         FIG. 5  is a partially cutaway perspective view of a fixing structure (second exemplary embodiment); 
         FIG. 6  is a sectional view of the fixing structure (second exemplary embodiment); 
         FIG. 7  is a partially cutaway perspective view of a fixing structure (third exemplary embodiment); 
         FIG. 8  is a sectional view of the fixing structure (third exemplary embodiment); 
         FIG. 9  is a flowchart showing a fixing method; 
         FIG. 10  is a perspective view of a circuit board; 
         FIG. 11  is a perspective view showing a state in which each conductive pattern is coated with cream solder; 
         FIG. 12  is a perspective view showing a state of the circuit board after a reflow process is performed on the circuit board in a reflow furnace; 
         FIG. 13  is a perspective view showing a state in which a connector is disposed on the circuit board; 
         FIG. 14  is an enlarged view of a portion “B” shown in  FIG. 13 ; 
         FIG. 15  is a perspective view showing a state in which a laser beam is irradiated onto an upper surface of a fixed portion of each terminal; 
         FIG. 16  is a perspective view showing a state in which a penetrating hole is formed in each terminal; 
         FIG. 17  is a perspective view of a harness (fourth exemplary embodiment); 
         FIG. 18  is a partially cutaway perspective view of the harness (fourth exemplary embodiment); 
         FIG. 19  is an exploded perspective view of the harness (fourth exemplary embodiment); 
         FIG. 20  is a view showing a state in which wires are removed from a wire holding body (fourth exemplary embodiment); 
         FIG. 21  is an enlarged view of a portion “C” shown in  FIG. 18  (fourth exemplary embodiment); 
         FIG. 22  is a partially cutaway perspective view of a fixing structure (fourth exemplary embodiment); 
         FIG. 23  is a sectional view of the fixing structure (fourth exemplary embodiment); 
         FIG. 24  is a partially cutaway perspective view of a fixing structure (fifth exemplary embodiment); 
         FIG. 25  is a sectional view of the fixing structure (fifth exemplary embodiment); 
         FIG. 26  is a partially cutaway perspective view of a fixing structure (sixth exemplary embodiment); 
         FIG. 27  is a sectional view of the fixing structure (sixth exemplary embodiment); 
         FIG. 28  is a flowchart showing a fixing method; 
         FIG. 29  is a perspective view showing a state in which a laser beam is irradiated onto an upper surface of a fixed portion of each terminal; 
         FIG. 30  is a perspective view showing a state in which a penetrating hole is formed in each terminal; 
         FIG. 31  is a view corresponding to  FIG. 21  and showing a case where a laser beam is irradiated onto a plurality of locations (first modified example); 
         FIG. 32  is a perspective view showing a wire holding body (second modified example); 
         FIG. 33  is a perspective view showing a wire holding body (third modified example); 
         FIG. 34  is an exploded perspective view of a harness (fourth modified example); 
         FIG. 35  is a partially cutaway perspective view of a harness (fifth modified example); 
         FIG. 36  is a sectional view of a harness (sixth modified example); and 
         FIG. 37  is a diagram corresponding to FIG. 1 of Japanese Unexamined Patent Application Publication No. 2003-204149. 
     
    
    
     DESCRIPTION OF THE EXEMPLARY EMBODIMENTS 
     First Exemplary Embodiment 
     A first exemplary embodiment will be described below with reference to  FIGS. 1 to 4 . 
       FIG. 1  is a perspective view of a circuit module  1 . The circuit module  1  includes a circuit board  2 , a connector  3  (electronic component), and an adhesive layer  4 . 
     The circuit board  2  includes an insulating substrate (substrate)  5  and a plurality of conductive patterns  6 . The insulating substrate  5  is formed of, for example, a glass epoxy resin or paper phenol. The plurality of conductive patterns  6  are formed on a connector mounting surface  7  of the insulating substrate  5 . Each of the plurality of conductive patterns  6  is formed of, for example, a copper foil or aluminum foil. 
     The connector  3  includes a housing  8  and a plurality of terminals  9 . The housing  8  is formed of an insulating resin. Each of the plurality of terminals  9  is formed of a Cu-based or Au-based metal. In the first exemplary embodiment, each of the plurality of terminals  9  is formed of a Cu-based metal and is plated with gold.  FIG. 2  is an enlarged view of a portion “A” shown in  FIG. 1 . As shown in  FIG. 2 , each terminal  9  includes a fixed portion  10 . The fixed portion  10  corresponds to a leading end portion of each terminal  9 . The thickness direction of the fixed portion  10  is orthogonal to the connector mounting surface  7  of the insulating substrate  5 . The fixed portion  10  is elongated in a direction parallel to the connector mounting surface  7  of the insulating substrate  5 . The fixed portion  10  includes an upper surface  11  (laser beam irradiation surface), two side surfaces  12 , and a lower surface  13 . The fixed portion  10  of each terminal  9  is fixed to the corresponding conductive pattern  6  with the adhesive layer  4  disposed therebetween. The insulating substrate  5 , the conductive pattern  6 , the adhesive layer  4 , and the fixed portion  10  constitute a fixing structure E. 
     The adhesive layer  4  is formed of a brazing filler metal F. In the first exemplary embodiment, the brazing filler metal F that forms the adhesive layer  4  is a solder. 
     The fixing structure E will be described in detail below with reference to  FIGS. 3 and 4 .  FIG. 3  is a partially cutaway perspective view of the fixing structure E.  FIG. 4  is a sectional view of the fixing structure E. 
     Referring to  FIGS. 3 and 4 , the adhesive layer  4  and the conductive pattern  6  are fixed to each other by wetting phenomena. The adhesive layer  4  is melted and solidified, which allows the adhesive layer  4  and the conductive pattern  6  to be fixed to each other. 
     In contrast, the adhesive layer  4  and the fixed portion  10  are fixed to each other with the brazing filler metal F extending within the fixed portion  10  in such a manner that the brazing filler metal F gradually increases in width in a direction apart from the insulating substrate  5 . In other words, the brazing filler metal F projects into the fixed portion  10  from the adhesive layer  4 , and the brazing filler metal F present in the fixed portion  10  gradually increases in width in the direction apart from the insulating substrate  5 . The brazing filler metal F present in the fixed portion  10  gradually widens in the direction apart from the insulating substrate  5 . 
     Specifically, a penetrating hole  14  that penetrates the fixed portion  10  in a direction orthogonal to the connector mounting surface  7  is formed in the fixed portion  10 . As shown in  FIG. 4 , the penetrating hole  14  includes an upper opening  15  and a lower opening  16 . The upper opening  15  has a substantially circular shape and is opened at the upper surface  11 , and the lower opening  16  has a substantially circular shape and is opened at the lower surface  13 . The diameter of the upper opening  15  is larger than the diameter of the lower opening  16 . In other words, the opening area of the upper opening  15  is larger than the opening area of the lower opening  16 . Accordingly, the penetrating hole  14  gradually increases in width in the direction apart from the insulating substrate  5 . The penetrating hole  14  gradually widens in the direction apart from the insulating substrate  5 . An inner peripheral surface  17  of the penetrating hole  14  is curved to be convex inward. Specifically, in a section of the fixing structure E, two boundary lines K (boundaries) between the fixed portion  10  and the brazing filler metal F extending within the fixed portion  10  are curved to be convex inward. In a section of the fixing structure E, the two boundary lines K (boundaries) between the fixed portion  10  and the brazing filler metal F extending within the penetrating hole  14  of the fixed portion  10  are curved to be convex inward. The brazing filler metal F extends upward from the adhesive layer  4 . The brazing filler metal F penetrates the penetrating hole  14  of the fixed portion  10  vertically. The brazing filler metal F is exposed at the upper surface  11  of the fixed portion  10 . The brazing filler metal F is filled in the penetrating hole  14  of the fixed portion  10 . The brazing filler metal F gradually increases in width in the direction apart from the insulating substrate  5 . The brazing filler metal F extends within the penetrating hole  14 , which is gradually narrowed in a direction approaching the insulating substrate  5 , in such a manner that the brazing filler metal F gradually increases in width in the direction apart from the insulating substrate  5 . With this structure, the fixed portion  10  and the adhesive layer  4  are fixed to each other. 
     In the vicinity of the lower surface  13  of the fixed portion  10 , a metal G having the same metal component as the metal component of the terminal  9  is present slightly irregularly in the brazing filler metal F. 
     The first exemplary embodiment described above has the following features. 
     The fixing structure E includes the insulating substrate  5  (substrate), the conductive pattern  6  formed on the insulating substrate  5 , the adhesive layer  4  formed of the brazing filler metal F, and the terminal  9 . The terminal  9  is fixed to the conductive pattern  6  by the adhesive layer  4 . The terminal  9  and the adhesive layer  4  are fixed to each other with the brazing filler metal F extending within the terminal  9  in such a manner that the brazing filler metal F gradually increases in width in the direction apart from the insulating substrate  5 . In other words, the penetrating hole  14  is formed in the terminal  9 , the penetrating hole  14  being gradually widened in a direction apart from the insulating substrate  5 , and the penetrating hole  14  is filled with the brazing filler metal F. According to the above structure, the terminal  9  and the adhesive layer  4  are firmly fixed to each other. 
     The fixing structure E includes at least: one insulating substrate  5 ; one conductive pattern  6 ; one adhesive layer  4 ; and one terminal  9 . 
     The brazing filler metal F penetrates the terminal  9  and reaches the vicinity of the upper surface  11  of the terminal  9 . According to the above structure, whether the terminal  9  and the adhesive layer  4  are fixed to each other can be confirmed by visually recognizing the brazing filler metal F when the upper surface  11  of the terminal  9  is viewed from above. 
     As shown in  FIG. 4 , the boundary lines K between the terminal  9  and the brazing filler metal F extending within the terminal  9  are curved. In other words, the boundary lines K between the penetrating hole  14  and the brazing filler metal F are curved. According to the above structure, the contact area between the terminal  9  and the adhesive layer  4  is larger than that in a case where the boundary lines K are straight lines. Therefore, the terminal  9  and the adhesive layer  4  are more firmly fixed to each other. 
     As shown in  FIG. 4 , the boundary lines K between the terminal  9  and the brazing filler metal F extending within the terminal  9  are curved to be convex inward. In other words, the boundary lines K between the penetrating hole  14  and the brazing filler metal F is curved to be convex inward. According to the above structure, the volume of the internal space of the penetrating hole  14  can be reduced as compared with a case where the boundary lines K are curved to be convex outward. Therefore, the usage of the brazing filler metal F can be reduced. 
     Note that each boundary line K may look like a solid line, a dashed line, a dotted line, a dashed-dotted line, or an alternate long and two short dashes line. 
     While in the exemplary embodiment described above, the penetrating hole  14  that penetrates the fixed portion  10  in the direction orthogonal to the connector mounting surface  7  is formed in the fixed portion  10 , the penetrating hole  14  may be formed in such a manner that the penetrating hole  14  penetrates the fixed portion  10  in a direction oblique to the connector mounting surface  7 . 
     Second Exemplary Embodiment 
     Next, a second exemplary embodiment will be described with reference to  FIGS. 5 and 6 . Differences between the first exemplary embodiment and the second embodiment will be mainly described, while a repeat of previous descriptions is omitted. 
     As shown in  FIG. 3 , in the first exemplary embodiment described above, the brazing filler metal F penetrates the terminal  9  and reaches the vicinity of the upper surface  11  of the fixed portion  10 . 
     In contrast, in the second exemplary embodiment, as shown in  FIGS. 5 and 6 , the brazing filler metal F penetrates the terminal  9  and spreads over the upper surface  11  of the fixed portion  10  in a substantially circular shape. Specifically, as shown in  FIG. 6 , the brazing filler metal F spreads in a substantially circular shape to the outside of the upper opening  15  of the penetrating hole  14 . The brazing filler metal F is deposited on the upper surface  11  of the fixed portion  10  at the outside of the upper opening  15  of the penetrating hole  14 . 
     According to the above structure, the state in which the terminal  9  and the adhesive layer  4  are fixed to each other can be confirmed by visually recognizing the brazing filler metal F when the upper surface  11  of the terminal  9  is viewed from above. Further, since the area of the brazing filler metal F when the upper surface  11  of the terminal  9  is viewed from above is larger than that of the first exemplary embodiment described above, the brazing filler metal F can be easily recognized visually when the upper surface  11  of the terminal  9  is viewed from above. Furthermore, since the brazing filler metal F spreads over the upper surface  11  of the fixed portion  10 , the fixed portion  10  and the adhesive layer  4  are more firmly fixed to each other as compared with the case of the first exemplary embodiment in which the brazing filler metal F does not spread over the upper surface  11  of the fixed portion  10 . 
     Third Exemplary Embodiment 
     Next, a third exemplary embodiment will be described with reference to  FIGS. 7 and 8 . Differences between the first exemplary embodiment and the third embodiment will be mainly described, while a repeat of previous descriptions is omitted. 
     As shown in  FIG. 3 , in the first exemplary embodiment described above, the brazing filler metal F penetrates the terminal  9  and reaches the vicinity of the upper surface  11  of the fixed portion  10 . 
     In contrast, in the third exemplary embodiment, as shown in  FIGS. 7 and 8 , the brazing filler metal F penetrates the terminal  9  and spreads over the upper surface  11  of the fixed portion  10  in a substantially circular shape. Specifically, as shown in  FIG. 8 , the brazing filler metal F spreads in a substantially circular shape to the outside of the upper opening  15  of the penetrating hole  14 , and reaches the two side surfaces  12 . The brazing filler metal F is deposited on the upper surface  11  and the two side surfaces  12  of the fixed portion  10  at the outside of the upper opening  15  of the penetrating hole  14 . 
     According to the above structure, the state in which the terminal  9  and the adhesive layer  4  are fixed to each other can be confirmed by visually recognizing the brazing filler metal F when the upper surface  11  of the terminal  9  is viewed from above. Further, since the area of the brazing filler metal F when the upper surface  11  of the terminal  9  is viewed from above is larger than that of the first exemplary embodiment described above, the brazing filler metal F can be easily recognized visually when the upper surface  11  of the terminal  9  is viewed from above. Furthermore, since the brazing filler metal F spreads over the upper surface  11  of the fixed portion  10 , the fixed portion  10  and the adhesive layer  4  are more firmly fixed to each other as compared with the case of the first exemplary embodiment in which the brazing filler metal F does not spread over the upper surface  11  of the fixed portion  10 . 
     (Fixing Method) 
     Referring to  FIGS. 9 to 16 , a fixing method for fixing each terminal  9  to the corresponding conductive pattern  6  via the brazing filler metal F will be described below.  FIG. 9  is a flowchart showing the fixing method.  FIGS. 10 to 16  are views showing the state of each process of the fixing method. 
     As shown in  FIG. 9 , the fixing method includes a first step (S 300 ), a second step (S 310 ), and a third step (S 320 ) in this order. The first step (S 300 ), the second step (S 310 ), and the third step (S 320 ) will be described below in this order. 
     (First Step: S 300 ) 
     In the first step, the brazing filler metal F is disposed on the conductive pattern  6  as described in detail below. 
     As shown in  FIG. 10 , the plurality of conductive patterns  6  are formed on the connector mounting surface  7  of the insulating substrate  5 . As shown in  FIG. 11 , a cream solder printer (not shown) coats each conductive pattern  6  with a cream solder C. Next, the circuit board  2  is placed in a reflow furnace (not shown) and a reflow process is carried out. As a result, as shown in  FIG. 12 , the brazing filler metal F which is solidified and slightly rounded by surface tension is formed on the corresponding conductive pattern  6 . At this time, the brazing filler metal F wets the corresponding conductive pattern  6 . 
     (Second Step: S 310 ) 
     In the second step, each terminal  9  is brought into contact with the brazing filler metal F as described in detail below. 
     As shown in  FIG. 13 , a surface mounter (not shown) sucks and holds the connector  3  by using a suction nozzle  18 , and disposes the connector  3  at a desired position on the circuit board  2 . Specifically, as shown in  FIG. 14 , the surface mounter disposes the connector  3  on the circuit board  2  in such a manner that the fixed portion  10  of each terminal  9  is opposed to the brazing filler metal F in the vertical direction and is brought into contact with the brazing filler metal F. At this time, the surface mounter disposes the connector  3  on the circuit board  2  in such a manner that the fixed portion  10  of each terminal  9  is pressed against the brazing filler metal F. When the fixed portion  10  of each terminal  9  is pressed against the brazing filler metal F, each terminal  9  is slightly bent and deformed in the vertical direction. 
     (Third Step: S 320 ) 
     In the third step, a laser beam L is irradiated onto the fixed portion  10  of each terminal  9 , thereby forming the penetrating hole  14  in the fixed portion  10  of each terminal  9  as described in detail below. 
     As shown in  FIG. 15 , a laser oscillator (not shown) irradiates the laser beam L onto the upper surface  11  (laser beam irradiation surface) of the fixed portion  10  of each terminal  9 . The wavelength of the laser beam L irradiated onto the upper surface  11  of the fixed portion  10  of each terminal  9  is preferably, for example, 600 nm or less. The laser beam L having a wavelength of 600 nm or less has a high absorptance with respect to a Cu-based or Au-based metal, which enables each terminal  9  to be melted in a short period of time. Examples of the laser beam L having a wavelength of 600 nm or less include the second harmonic of YAG laser. The wavelength of the second harmonic of YAG laser is 532 nm. The third harmonic or the fourth harmonic of YAG laser may be used instead of the second harmonic of YAG laser. Other lasers such as a CO 2  laser or an excimer laser may be used instead of the YAG laser. The irradiation position of the laser beam L is within the region in which the fixed portion  10  of each terminal  9 , the brazing filler metal F, and the conductive pattern  6  overlap each other in the irradiation direction of the laser beam L. 
     When the laser beam L is irradiated onto the upper surface  11  of the fixed portion  10  of each terminal  9 , the fixed portion  10  of each terminal  9  is locally vaporized, and as shown in  FIG. 16 , the penetrating hole  14  (key hole) extending vertically is formed in the fixed portion  10  of each terminal  9 . The penetrating hole  14  is formed in such a manner that the penetrating hole  14  is gradually narrowed toward the corresponding conductive pattern  6 . 
     After the irradiation of the laser beam L is finished, the melted brazing filler metal F enters the penetrating hole  14  and the brazing filler metal F is solidified within the penetrating hole  14  as shown in  FIGS. 3 to 8 . As a result, the fixed portion  10  of each terminal  9  and the brazing filler metal F are fixed to each other. Irradiation conditions, such as the wavelength of the laser beam L and an irradiation time, may be set so that the brazing filler metal F melted by the irradiation of the laser beam L enters the penetrating hole  14  and reaches the vicinity of the upper opening  15  (upper end) of the penetrating hole  14  as shown in  FIGS. 3 to 8 . 
     Various principles can be applied as the principle that the melted brazing filler metal F enters the penetrating hole  14 , but the present inventors consider as follows. 
     That is, first, when the laser beam L is irradiated onto the fixed portion  10  of each terminal  9 , the fixed portion  10  of each terminal  9  is locally vaporized and the penetrating hole  14  is formed, and at the same time, the entire brazing filler metal F is melted once. When the laser beam L is irradiated onto the fixed portion  10  of each terminal  9 , the fixed portion  10  of each terminal  9  is pressed against the brazing filler metal F, so that an external force to compress the brazing filler metal F acts on the melted brazing filler metal F. Due to the external force, the melted brazing filler metal F enters the penetrating hole  14  in such a manner that the brazing filler metal F is pressed out to the penetrating hole  14  and is pressed into the penetrating hole  14 . The state in which the fixed portion  10  of each terminal  9  is pressed against the brazing filler metal F includes at least one of a state in which the fixed portion  10  of each terminal  9  is pressed against the brazing filler metal F actively by the surface mounter or by the spring restoring force of each terminal  9 , and a state in which the fixed portion  10  of each terminal  9  is pressed against the brazing filler metal F by the weight of the connector  3 . 
     The brazing filler metal F disposed on each conductive pattern  6  in the first step (S 300 ) is not formed with a thickness of about 0.1 to several micrometers, which are implemented in a plating process, but is formed with a thickness of about several tens of micrometers to several hundreds of micrometers, which are implemented in, for example, the reflow process. It is estimated that the formation of the brazing filler metal F with such a thickness allows the brazing filler metal F to be melted and flow into the penetrating hole  14  of each terminal  9  before the heat generated in each terminal  9  by the irradiation of the laser beam L onto each terminal  9  defuses to the conductive pattern  6  and the insulating substrate  5 . 
     Second, the melted brazing filler metal F is sucked into the penetrating hole  14  which is formed due to the irradiation of the laser beam L. 
     The fixing method described above has the following features. 
     The fixing method for fixing each terminal  9  to the corresponding conductive pattern  6  (object to be fixed) with the brazing filler metal F disposed therebetween includes: the first step (S 300 ) of disposing the brazing filler metal F on the conductive pattern  6 ; the second step (S 310 ) of bringing the terminal  9  into contact with the brazing filler metal F; and the third step (S 320 ) of forming the penetrating hole  14  in the terminal  9  by irradiating the laser beam L onto the terminal  9 . In the third step (S 320 ), the laser beam L is irradiated onto the terminal  9  in such a manner that the brazing filler metal F melted by the irradiation of the laser beam L enters the penetrating hole  14  and reaches the vicinity of the upper opening  15  (upper end) of the penetrating hole  14 . In other words, in the third step (S 320 ), the laser beam L is irradiated onto the terminal  9  in such a manner that the penetrating hole  14  is filled with the brazing filler metal F melted by the irradiation of the laser beam L. According to the above method, the brazing filler metal F enters the penetrating hole  14 , which allows the terminal  9  to be fixed to the conductive pattern  6  with the brazing filler metal F disposed therebetween. The present inventors consider that the fixation between the terminal  9  and the brazing filler metal F is not due to wetting phenomena. Accordingly, the irradiation time of the laser beam L per terminal can be reduced in comparison with the case where the fixation between the terminal  9  and the brazing filler metal F is due to wetting phenomena. According to the above method, since the brazing filler metal F reaches the vicinity of the upper opening  15  (upper end) of the penetrating hole  14 , whether the terminal  9  and the brazing filler metal F are fixed to each other can be confirmed when the upper surface  11  (laser beam irradiation surface) of the terminal  9  is viewed from above. 
     In the third step (S 320 ), the laser beam L may be irradiated onto the terminal  9  in such a manner that the brazing filler metal F melted by the irradiation of the laser beam L enters the penetrating hole  14 , flows out of the upper opening  15  (upper end) of the penetrating hole  14 , and spreads over the upper surface  11  (laser beam irradiation surface) of the terminal  9 . In other words, in the third step (S 320 ), the laser beam L may be irradiated onto the terminal  9  in such a manner that the brazing filler metal F melted by the irradiation of the laser beam L flows out of the upper opening  15  (upper end) of the penetrating hole  14 , and spreads over the upper surface  11  (laser beam irradiation surface) of the terminal  9 . According to the above method, it is possible to more easily confirm whether the terminal  9  and the brazing filler metal F are fixed to each other when the upper surface  11  (laser beam irradiation surface) of the terminal  9  is viewed from above. Further, since the brazing filler metal F spreads over the upper surface  11  of the fixed portion  10 , the fixed portion  10  and the brazing filler metal F are more firmly fixed to each other as compared with a case where the brazing filler metal F does not spread over the upper surface  11  of the fixed portion  10 . 
     In the third step (S 320 ), the laser beam L is irradiated onto the terminal  9  while the terminal  9  is pressed against the brazing filler metal F. According to the above method, in the third step (S 320 ), the brazing filler metal F enters the penetrating hole  14  more easily than in a case where the laser beam L is irradiated onto the terminal  9  without pressing the terminal  9  against the brazing filler metal F. 
     In this exemplary embodiment, the brazing filler metal F is a solder. In the first step (S 300 ), the reflow process is carried out after the conductive pattern  6  is coated with the cream solder C, thereby disposing the brazing filler metal F on the conductive pattern  6 . That is, the reflow process is carried out once to mount other components on the circuit board  2 . Thus, the manufacturing process of the circuit module  1  can be simplified by using the reflow process when the brazing filler metal F is disposed on the conductive pattern  6 . 
     The terminal  9  is a Cu-based or Au-based metal. The brazing filler metal F is a solder. According to the above method, since the color of the terminal  9  is significantly different from the color of the brazing filler metal F, the terminal  9  and the brazing filler metal F can be easily distinguished from each other and recognized when the upper surface  11  (laser beam irradiation surface) of the terminal  9  is viewed from above. 
     In the above exemplary embodiments, the brazing filler metal F is a solder and the solder is a soft solder. Alternatively, a hard solder such as a silver solder, a gold solder, a copper solder, or a brass solder may be used as the brazing filler metal F. 
     EXAMPLES 
     Examples will be described below. 
     The circuit module  1  was produced under the following conditions.
     Insulating substrate  5 : made of a glass epoxy resin   Conductive pattern  6 : a copper foil (with a thickness of 18 micrometers)   Brazing filler metal F: an SnAgCu-based or SnZnBi-based lead-free solder (with a thickness of 100 micrometers)   Terminal  9 : a Cu-based metal (with a thickness of 80 micrometers) plated with gold   Laser beam L: the second harmonic of YAG laser (wavelength: 532 nm)   Energy density of laser beam irradiation: 19.1 J/mm 2      During laser beam irradiation, the fixed portion  10  of each terminal  9  is pressed against the brazing filler metal F to such an extent that each terminal  9  is slightly bent and deformed.   

     When the circuit module  1  was produced under the conditions described above, the fixing structure E as shown in  FIGS. 3, 5, and 7  was formed. 
     The exemplary embodiments described above can be modified as follows. 
     In the exemplary embodiments described above, the connector  3  is mounted on the circuit board  2 , but instead an FPIC (Flat Package Integrated Circuit) may be mounted on the circuit board  2 . In this case, the housing  8  of the connector  3  corresponds to the package of the FPIC, and the plurality of terminals  9  of the connector  3  correspond to a plurality of lead frames included in the FPIC. 
     In the third step (S 320 ), the laser beam L is irradiated onto the fixed portion  10  of each terminal  9  while the surface mounter presses the fixed portion  10  of each terminal  9  against the brazing filler metal F. However, means for pressing the fixed portion  10  of each terminal  9  against the brazing filler metal F is not limited to this. For example, a structure can be adopted in which the connector  3  includes: a first terminal that contacts a first surface of the circuit board  2 ; and a second terminal that contacts a second surface opposite to the first surface of the circuit board  2 , and the first terminal and the second terminal resiliently sandwich the circuit board  2  by the elastic restoring force of the first terminal and the second terminal. When the laser beam L is irradiated onto the fixed portion  10  of each terminal  9 , the thickness direction of the fixed portion  10  of each terminal  9  is not necessarily orthogonal to the connector mounting surface  7  of the insulating substrate  5  of the circuit board  2 , but instead the fixed portion  10  of each terminal  9  may be slightly inclined with respect to the circuit board  2 . The laser beam L may be irradiated onto the fixed portion  10  of each terminal  9  while the fixed portion  10  of each terminal  9  is simply opposed to the brazing filler metal F. 
     Fourth Exemplary Embodiment 
     A fourth exemplary embodiment will be described below with reference to  FIGS. 17 to 23 . 
     As shown in  FIG. 17 , a harness  30  includes a connector  31  and two wires  32 . 
     As shown in  FIG. 18 , the connector  31  includes two terminals  33  and a housing S (fixing structure body). The housing S includes a terminal holding body  34  and a wire holding body  35 . 
     As shown in  FIG. 19 , the terminal holding body  34  is a portion that holds the two terminals  33 . The terminal holding body  34  includes a substantially rectangular parallelepiped mating portion  36 , two rear projecting portions  37  (also see  FIG. 17 ), and a coupling beam  38 . The mating portion  36  is a portion to be mated with a mating connector. Two mating dents  39  are formed in a front surface  36 A of the mating portion  36 . The two rear projecting portions  37  are formed so as to project backward from a back surface  36 B of the mating portion  36 . The two rear projecting portions  37  are disposed separately at right and left sides. A lock dent  40  is formed in an inner surface  37 A of each rear projecting portion  37 . The coupling beam  38  couples upper ends  37 C of rear ends  37 B of the respective rear projecting portions  37 . The coupling beam  38  includes a lower surface  38 A. The terminal holding body  34  is formed of an insulating resin. 
     Each terminal  33  is elongated in a front-back direction. Each terminal  33  is held on the terminal holding body  34  by insert molding. Each terminal  33  includes: a contact portion  33 A that projects within the corresponding mating dent  39 ; an embedded portion  33 F that is embedded in the terminal holding body  34 ; and a fixed portion  33 B that projects backward from the back surface  36 B. The fixed portion  33 B includes an upper surface  33 C, a lower surface  33 D (fixed surface), and two side surfaces  33 E. Each terminal  33  is formed of a Cu-based or Au-based metal. In the fourth exemplary embodiment, each terminal  33  is formed of a Cu-based metal and is plated with gold. 
     As shown in  FIG. 20 , each wire  32  includes a conductor  41  and an insulating coating  42  for coating the conductor  41 . The conductor  41  is formed of, for example, a Cu-based or Al-based metal, and is a solid wire or a strand. In the fourth exemplary embodiment, the conductor  41  is a Cu-based metal and is formed as a strand. The conductor  41  is exposed by a predetermined length by partially removing the insulating coating  42 . As shown in  FIG. 20 , the brazing filler metal F is deposited on the conductor  41  of each wire  32  due to wetting phenomena. 
     The wire holding body  35  is a portion that holds the two wires  32 . The wire holding body  35  includes an upper surface  35 A, a lower surface  35 B, a front surface  35 C, a back surface  35 D, and two side surfaces  35 E. The two side surfaces  35 E are parallel to each other. The lower surface  35 B has two wire holding grooves  43  each extending in the front-back direction. Each wire holding groove  43  is formed to have a substantially ohm-shaped section so that each wire  32  accommodated in the corresponding wire holding groove  43  is prevented from being removed from the corresponding wire holding groove  43 . In other words, when each wire  32  is inserted into the corresponding wire holding groove  43 , each wire  32  is held by the wire holding body  35 . Lock claws  44  are formed on the respective side surfaces  35 E. The wire holding body  35  is formed of an insulating resin having flexibility, such as a nylon-based resin or a polyester-based resin. 
     With the structure described above, each wire  32  is inserted into the corresponding wire holding grooves  43  in a direction indicated by an arrow P in  FIG. 20  and the wire holding body  35  is inserted between the two rear projecting portions  37  of the terminal holding body  34  in a direction indicated by an arrow Q in  FIG. 19 . As a result, the upper surface  35 A of the wire holding body  35  is opposed to the lower surface  38 A of the coupling beam  38  of the terminal holding body  34 ; the two side surfaces  35 E of the wire holding body  35  are respectively opposed to the inner surfaces  37 A of the two rear projecting portions  37  of the terminal holding body  34 ; and the two lock claws  44  of the wire holding body  35  respectively engage with the two lock dents  40  of the terminal holding body  34 . Thus, the wire holding body  35  is mated to the terminal holding body  34  and the wire holding body  35  is held by the terminal holding body  34 . A fitting mechanism for regulating disengagement of the wire holding body  35  after the wire holding body  35  is mated to the terminal holding body  34  may be provided instead of the lock claws  44 . 
       FIG. 21  shows an enlarged view of a portion “C” shown in  FIG. 18 . As shown in  FIG. 21 , the fixed portion  33 B of each terminal  33  is fixed to the conductor  41  of each wire  32  with the brazing filler metal F disposed therebetween. One wire  32  including the conductor  41 , the brazing filler metal F wetting the conductor  41 , and the fixed portion  33 B of one terminal  33  constitute the fixing structure E. In the fourth exemplary embodiment, the brazing filler metal F is a solder. 
     The fixing structure E will be described in detail below with reference to  FIGS. 22 and 23 .  FIG. 22  is a partially cutaway perspective view of the fixing structure E.  FIG. 23  is a sectional view of the fixing structure E. 
     As shown in  FIGS. 22 and 23 , the conductor  41  is opposed to the lower surface  33 D of the fixed portion  33 B. The conductor  41  extends in the front-back direction. Accordingly, the longitudinal direction of the terminal  33  and the longitudinal direction of the conductor  41  are parallel to each other. 
     The brazing filler metal F and the conductor  41  are fixed to each other due to wetting phenomena. The brazing filler metal F is melted and solidified, which allows the brazing filler metal F and the conductor  41  to be fixed to each other. 
     The brazing filler metal F and the fixed portion  33 B are fixed to each other with the brazing filler metal F extending within the fixed portion  33 B in such a manner that the brazing filler metal F gradually increases in width in a direction apart from a central axis  41 C of the conductor  41 . The brazing filler metal F present in the fixed portion  33 B gradually increases in width in the direction apart from the central axis  41 C of the conductor  41 . The brazing filler metal F present in the fixed portion  33 B gradually widens in the direction apart from the central axis  41 C of the conductor  41 . 
     Specifically, a penetrating hole  45  that penetrates the fixed portion  33 B in a direction orthogonal to the lower surface  33 D is formed in the fixed portion  33 B. As shown in  FIG. 23 , the penetrating hole  45  has a substantially circular upper opening  46  (upper end) that is opened at the upper surface  33 C, and a substantially circular lower opening  47  that is opened at the lower surface  33 D. The diameter of the upper opening  46  is larger than the diameter of the lower opening  47 . In other words, the opening area of the upper opening  46  is larger than the opening area of the lower opening  47 . Accordingly, the penetrating hole  45  gradually increases in width in the direction apart from the central axis  41 C of the conductor  41 . The penetrating hole  45  gradually widens in the direction apart from the central axis  41 C of the conductor  41 . An inner peripheral surface  48  of the penetrating hole  45  is curved to be convex inward. In other words, two boundary lines K (boundaries) between the fixed portion  33 B and the brazing filler metal F extending within the fixed portion  33 B are curved to be convex inward in a section of the fixing structure E. The brazing filler metal F penetrates the penetrating hole  45  of the fixed portion  33 B vertically. The brazing filler metal F is exposed at the upper surface  33 C of the fixed portion  33 B. The brazing filler metal F is filled in the penetrating hole  45  of the fixed portion  33 B. The brazing filler metal F gradually increases in width in the direction apart from the central axis  41 C of the conductor  41 . The brazing filler metal F extends within the penetrating hole  45 , which is gradually narrowed toward the central axis  41 C of the conductor  41 , in such a manner that the brazing filler metal F gradually increases in width in the direction apart from the central axis  41 C of the conductor  41 . This structure allows the fixed portion  33 B and the brazing filler metal F to be fixed to each other. 
     In the vicinity of the lower surface  33 D of the fixed portion  33 B, the metal G having the same metal component as the metal component of the terminal  33  is present slightly irregularly in the brazing filler metal F. 
     The fourth exemplary embodiment described above has the following features. 
     The fixing structure E includes: the wire  32  including the conductor  41 ; the brazing filler metal F wetting the conductor  41 ; and the terminal  33 . The terminal  33  is fixed to the conductor  41  by the brazing filler metal F. The brazing filler metal F extends within the terminal  33  in such a manner that the brazing filler metal F gradually increases in width in the direction apart from the central axis  41 C of the conductor  41 , thereby allowing the terminal  33  and the brazing filler metal F to be fixed to each other. In other words, the penetrating hole  45  is formed in the terminal  33 , the penetrating hole  45  being gradually widened in a direction apart from the central axis  41 C of the conductor  41 , and the penetrating hole  45  is filled with the brazing filler metal F. According to the above structure, the terminal  33  and the brazing filler metal F are firmly fixed to each other. 
     The fixing structure E includes at least: one wire  32  including the conductor  41 , the brazing filler metal F, and one terminal  33 . 
     The brazing filler metal F penetrates the terminal  33  and reaches the vicinity of the upper surface  33 C of the terminal  33 . According to the above structure, the state in which the terminal  33  and the brazing filler metal F are fixed to each other can be confirmed by visually recognizing the brazing filler metal F when the upper surface  33 C of the terminal  33  is viewed from above. 
     As shown in  FIG. 23 , the boundary lines K between the terminal  33  and the brazing filler metal F extending within the terminal  33  are curved. In other words, the boundary lines K between the penetrating hole  45  and the brazing filler metal F are curved. According to the above structure, the contact area between the terminal  33  and the brazing filler metal F is larger than that in a case where the boundary lines K are straight lines. Thus, the terminal  33  and the brazing filler metal F are more firmly fixed to each other. 
     Further, as shown in  FIG. 23 , the boundary lines K between the terminal  33  and the brazing filler metal F extending within the terminal  33  are curved to be convex inward. In other words, the boundary lines K between the penetrating hole  45  and the brazing filler metal F are curved to be convex inward. According to the above structure, the volume of the internal space of the penetrating hole  45  can be reduced as compared with a case where the boundary lines K are curved to be convex outward. Thus, the usage of the brazing filler metal F can be reduced. 
     Note that each boundary line K may look like a solid line, a dashed line, a dotted line, a dashed-dotted line, or an alternate long and two short dashes line. 
     The fixing structure E further includes the housing S (fixing structure body) including the wire holding body  35  that holds two wires  32 , and the terminal holding body  34  that holds two terminals  33 . The wire holding body  35  and the terminal holding body  34  are mated together. According to the above structure, when the terminal  33  and the conductor  41  are fixed to each other, the conductor  41  can be accurately positioned with respect to the terminal  33 . 
     In the exemplary embodiments described above, the penetrating hole  45  that penetrates the fixed portion  33 B in the direction orthogonal to the lower surface  33 D is formed in the fixed portion  33 B. Alternatively, the penetrating hole  45  may be formed in such a manner that the penetrating hole  45  penetrates the fixed portion  33 B in a direction oblique to the lower surface  33 D. 
     Fifth Exemplary Embodiment 
     Next, a fifth exemplary embodiment will be described with reference to  FIGS. 24 and 25 . Differences between the fourth exemplary embodiment and the fifth embodiment will be mainly described, while a repeat of previous descriptions is omitted. 
     As shown in  FIG. 23 , in the fourth exemplary embodiment described above, the brazing filler metal F penetrates the terminal  33  and reaches the vicinity of the upper surface  33 C of the fixed portion  33 B. 
     In contrast, in the fifth exemplary embodiment, as shown in  FIGS. 24 and 25 , the brazing filler metal F penetrates the terminal  33  and spreads over the upper surface  33 C of the fixed portion  33 B in a substantially circular shape. Specifically, as shown in  FIG. 25 , the brazing filler metal F extends in a substantially circular shape to the outside of the upper opening  46  of the penetrating hole  45 . The brazing filler metal F is deposited on the upper surface  33 C of the fixed portion  33 B at the outside of the upper opening  46  of the penetrating hole  45 . 
     According to the above structure, the state in which the terminal  33  and the brazing filler metal F are fixed to each other can be confirmed by visually recognizing the brazing filler metal F when the upper surface  33 C of the terminal  33  is viewed from above. Further, since the area of the brazing filler metal F when the upper surface  33 C of the terminal  33  is viewed from above is larger than that of the fourth exemplary embodiment described above, the brazing filler metal F can be easily recognized visually when the upper surface  33 C of the terminal  33  is viewed from above. Furthermore, since the brazing filler metal F spreads over the upper surface  33 C of the fixed portion  33 B, the fixed portion  33 B and the brazing filler metal F are more firmly fixed to each other as compared with the fourth exemplary embodiment in which the brazing filler metal F does not spread over the upper surface  33 C of the fixed portion  33 B. 
     Sixth Embodiment 
     Next, a sixth embodiment will be described with reference to  FIGS. 26 and 27 . Differences between the fourth exemplary embodiment and the sixth embodiment will be mainly described, while a repeat of previous descriptions is omitted. 
     As shown in  FIG. 23 , in the fourth exemplary embodiment described above, the brazing filler metal F penetrates the terminal  33  and reaches the vicinity of the upper surface  33 C of the fixed portion  33 B. 
     In contrast, in the sixth exemplary embodiment, as shown in  FIGS. 26 and 27 , the brazing filler metal F penetrates the terminal  33  and spreads over the upper surface  33 C of the fixed portion  33 B in a substantially circular shape. Specifically, as shown in  FIG. 27 , the brazing filler metal F extends in a substantially circular shape to the outside of the upper opening  46  of the penetrating hole  45 , and reaches the two side surfaces  33 E. Further, the brazing filler metal F is deposited on the upper surface  33 C and the two side surfaces  33 E of the fixed portion  33 B at the outside of the upper opening  46  of the penetrating hole  45 . 
     According to the above structure, the state in which the terminal  33  and the brazing filler metal F are fixed to each other can be confirmed by visually recognizing the brazing filler metal F when the upper surface  33 C of the terminal  33  is viewed from above. Further, since the area of the brazing filler metal F when the upper surface  33 C of the terminal  33  is viewed from above is larger than that of the fourth exemplary embodiment described above, the brazing filler metal F can be easily recognized visually when the upper surface  33 C of the terminal  33  is viewed from above. Furthermore, since the brazing filler metal F spreads over the upper surface  33 C of the fixed portion  33 B, the fixed portion  33 B and the brazing filler metal F are more firmly fixed to each other as compared with the fourth exemplary embodiment in which the brazing filler metal F does not spread over the upper surface  33 C of the fixed portion  33 B. 
     (Fixing Method) 
     A fixing method for fixing each terminal  33  to the corresponding conductor  41  of the wire  32  with the brazing filler metal F disposed therebetween will be described below with reference to  FIGS. 28 to 30 .  FIG. 28  is a flowchart showing the fixing method.  FIGS. 29 and 30  are views showing each process of the fixing method. 
     As shown in  FIG. 28 , the fixing method includes a first step (S 400 ), a second step (S 410 ), and a third step (S 420 ) in this order. The first step (S 400 ), the second step (S 410 ), and the third step (S 420 ) will be described below in this order. 
     (First Step: S 400 ) 
     In the first step, the brazing filler metal F is disposed on the conductor  41 . Specifically, the brazing filler metal F is disposed on the conductor  41  by wetting the conductor  41  with the brazing filler metal F. 
     (Second Step: S 410 ) 
     In the second step, the terminal  33  is brought into contact with the brazing filler metal F as described in detail below. 
     That is, the wire holding body  35  and the terminal holding body  34  are mated together in the direction indicated by the arrow Q in  FIG. 19 , thereby bringing the terminal  33  into contact with the brazing filler metal F. At this time, the brazing filler metal F is pressed against the terminal  33 , while the conductor  41  is subjected to a slight bending deformation. 
     (Third Step: S 420 ) 
     In the third step, the laser beam L is irradiated onto the fixed portion  33 B of each terminal  33 , thereby forming the penetrating hole  45  in the fixed portion  33 B of each terminal  33  as described in detail below. 
     That is, as shown in  FIG. 29 , a laser oscillator (not shown) irradiates the laser beam L onto the upper surface  33 C (laser beam irradiation surface) of the fixed portion  33 B of each terminal  33 . The wavelength of the laser beam L irradiated onto the upper surface  33 C of the fixed portion  33 B of each terminal  33  is preferably, for example, 600 nm or less. The laser beam L having a wavelength of 600 nm or less has a high absorptance with respect to a Cu-based or Au-based metal, which enables each terminal  33  to be melted in a short period of time. Examples of the laser beam L having a wavelength of 600 nm or less include the second harmonic of YAG laser. The wavelength of the second harmonic of YAG laser is 532 nm. The third harmonic or the fourth harmonic of YAG laser may be used instead of the second harmonic of YAG laser. Other lasers such as a CO 2  laser or an excimer laser may be used instead of the YAG laser. The irradiation position of the laser beam L is within the region in which the fixed portion  33 B of each terminal  33 , the brazing filler metal F disposed on the conductor  41 , and the conductor  41  overlap each other in the irradiation direction of the laser beam L. 
     When the laser beam L is irradiated onto the upper surface  33 C of the fixed portion  33 B of each terminal  33 , the fixed portion  33 B of each terminal  33  is locally vaporized, and as shown in  FIG. 30 , the penetrating hole  45  (key hole) extending vertically is formed in the fixed portion  33 B of each terminal  33 . The penetrating hole  45  is formed in such a manner that the penetrating hole  45  is gradually narrowed toward the central axis  41 C of the conductor  41 . 
     After the irradiation of the laser beam L is finished, the melted brazing filler metal F enters the penetrating hole  45  and the brazing filler metal F is solidified within the penetrating hole  45  as shown in  FIGS. 22 to 27 . Thus, the fixed portion  33 B of each terminal  33  and the brazing filler metal F are fixed to each other. The irradiation conditions, such as the wavelength of the laser beam L and the irradiation time, may be set so that the brazing filler metal F melted by the irradiation of the laser beam L enters the penetrating hole  45  and reaches the vicinity of the upper opening  46  (upper end) of the penetrating hole  45  as shown in  FIGS. 22 to 27 . 
     Various principles can be applied as the principle that the melted brazing filler metal F enters the penetrating hole  45 , but the present inventors consider as follows. 
     That is, first, when the laser beam L is irradiated onto the fixed portion  33 B of each terminal  33 , the fixed portion  33 B of each terminal  33  is locally vaporized and the penetrating hole  45  is formed, and at the same time, the entire brazing filler metal F is melted once. When the laser beam L is irradiated onto the fixed portion  33 B of each terminal  33 , the fixed portion  33 B of each terminal  33  is pressed against the brazing filler metal F, so that an external force to compress the brazing filler metal F acts on the melted brazing filler metal F. Due to the external force, the melted brazing filler metal F enters the penetrating hole  45  in such a manner that the brazing filler metal F is pressed out to the penetrating hole  45  and is pressed into the penetrating hole  45 . 
     The brazing filler metal F disposed on the conductor  41  in the first step (S 400 ) is not formed with a thickness of about 0.1 to several micrometers, which are implemented in the plating process, but is formed with a thickness of about several tens of micrometers to several hundreds of micrometers, which are implemented in, for example, the reflow process. It is estimated that the formation of the brazing filler metal F with such a thickness allows the brazing filler metal F to be melted and flow into the penetrating hole  45  of each terminal  33  before the heat generated in each terminal  33  by the irradiation of the laser beam L onto each terminal  33  defuses to the conductor  41 . 
     Second, the melted brazing filler metal F is sucked into the penetrating hole  45  which is formed due to the irradiation of the laser beam L. 
     The fixing method described above has the following features. 
     The fixing method for fixing each terminal  33  to the conductor  41  (object to be fixed) with the brazing filler metal F disposed therebetween includes: the first step (S 400 ) of disposing the brazing filler metal F on the conductor  41 ; the second step (S 410 ) of bringing the terminal  33  into contact with the brazing filler metal F; and the third step (S 420 ) of forming the penetrating hole  45  in the terminal  33  by irradiating the laser beam L onto the terminal  33 . In the third step (S 420 ), the laser beam L is irradiated onto the terminal  33  in such a manner that the brazing filler metal F melted by the irradiation of the laser beam L enters the penetrating hole  45  and reaches the vicinity of the upper opening  46  (upper end) of the penetrating hole  45 . In other words, in the third step (S 420 ), the laser beam L is irradiated onto the terminal  33  in such a manner that the penetrating hole  45  is filled with the brazing filler metal F melted by the irradiation of the laser beam L. According to the above method, when the brazing filler metal F enters the penetrating hole  45 , the terminal  33  is fixed to the conductor  41  with the brazing filler metal F disposed therebetween. The present inventors consider that the fixation between the terminal  33  and the brazing filler metal F is not due to wetting phenomena. Accordingly, the irradiation time of the laser beam L per terminal can be reduced in comparison with the case where the fixation between the terminal  33  and the brazing filler metal F is due to wetting phenomena. According to the above method, since the brazing filler metal F reaches the vicinity of the upper opening  46  (upper end) of the penetrating hole  45 , whether the terminal  33  and the brazing filler metal F are fixed to each other can be confirmed when the upper surface  33 C (laser beam irradiation surface) of the terminal  33  is viewed from above. 
     In the third step (S 420 ), the laser beam L may be irradiated onto the terminal  33  in such a manner that the brazing filler metal F melted by the irradiation of the laser beam L enters the penetrating hole  45 , flows out of the upper opening  46  (upper end) of the penetrating hole  45 , and spreads over the upper surface  33 C (laser beam irradiation surface) of the terminal  33 . In other words, in the third step (S 420 ), the laser beam L may be irradiated onto the terminal  33  in such a manner that the brazing filler metal F melted by the irradiation of the laser beam L flows out of the upper opening  46  (upper end) of the penetrating hole  45 , and spreads over the upper surface  33 C (laser beam irradiation surface) of the terminal  33 . According to the above method, whether the terminal  33  and the brazing filler metal F are fixed to each other can be more easily confirmed when the upper surface  33 C (laser beam irradiation surface) of the terminal  33  is viewed from above. Further, since the brazing filler metal F spreads over the upper surface  33 C of the fixed portion  33 B, the fixed portion  33 B and the brazing filler metal F are more firmly fixed to each other as compared with the case where the brazing filler metal F does not spread over the upper surface  33 C of the fixed portion  33 B. 
     In the third step (S 420 ), the laser beam L is irradiated onto the terminal  33  while the terminal  33  is pressed against the brazing filler metal F. According to the above method, in the third step (S 420 ), the brazing filler metal F enters the penetrating hole  45  more easily than in the case where the laser beam L is irradiated onto the terminal  33  without pressing the terminal  33  against the brazing filler metal F. 
     In the sixth exemplary embodiment, the brazing filler metal F is a solder. In the first step (S 400 ), the brazing filler metal F can be disposed on the conductor  41  by wetting the conductor  41  with the solder. 
     The terminal  33  is formed of a Cu-based or Au-based metal. The brazing filler metal F is a solder. According to the above method, since the color of the terminal  33  is significantly different from the color of the brazing filler metal F, the terminal  33  and the brazing filler metal F can be easily distinguished from each other and recognized when the upper surface  33 C (laser beam irradiation surface) of the terminal  33  is viewed from above. 
     In the second step (S 410 ), the wire holding body  35  that holds the wire  32  and the terminal holding body  34  that holds the terminal  33  are mated together, thereby bringing the terminal  33  into contact with the brazing filler metal F. According to the above method, the brazing filler metal F can be brought into contact with the terminal  33  with a simple operation. 
     In the second step (S 410 ), the wire holding body  35  that holds the wire  32  and the terminal holding body  34  that holds the terminal  33  are mated together, thereby bringing the terminal  33  into contact with the brazing filler metal F while the conductor  41  is subjected to a bending deformation. According to the above method, the brazing filler metal F can be brought into contact with the terminal  33  with a simple operation. In addition, a stable contact between the brazing filler metal F and the terminal  33  can be achieved. 
     According to the above exemplary embodiments, in the second step (S 410 ), the terminal  33  is brought into contact with the brazing filler metal F, while the conductor  41  is subjected to a bending deformation, by mating the wire holding body  35  holding the wire  32  with the terminal holding body  34  holding the terminal  33 . Alternatively, in the second step (S 410 ), the terminal  33  may be brought into contact with the brazing filler metal F, while the terminal  33  is subjected to a bending deformation, by mating the wire holding body  35  holding the wire  32  with the terminal holding body  34  holding the terminal  33 . In the second step (S 410 ), the terminal  33  may be brought into contact with the brazing filler metal F, while both of the conductor  41  and the terminal  33  are subjected to a bending deformation, by mating the wire holding body  35  holding the wire  32  with the terminal holding body  34  holding the terminal  33 . 
     In the above exemplary embodiments, the brazing filler metal F is a solder and the solder is a soft solder. Alternatively, a hard solder such as a silver solder, a gold solder, a copper solder, or a brass solder may be used as the brazing filler metal F. 
     First Modified Example 
     A first modified example will be described below with reference to  FIG. 31 . Differences between the first modified example and the fourth exemplary embodiment will be mainly described, while a repeat of previous descriptions is omitted. 
     In the fourth exemplary embodiment, when the laser beam L is irradiated onto the upper surface  33 C of the fixed portion  33 B of each terminal  33 , the number of irradiation positions of the laser beam L is only one. Accordingly, as shown in  FIG. 21 , the brazing filler metal F appears as a circle on the upper surface  33 C. 
     In contrast, in the first modified example, as shown in  FIG. 31 , the laser beam L may be irradiated at a plurality of different positions. The irradiation positions of the laser beam L are within the region in which the fixed portion  33 B of each terminal  33 , the brazing filler metal F, and the conductor  41  overlap each other in the irradiation direction of the laser beam L. Accordingly, as shown in  FIG. 31 , the brazing filler metal F appears as a plurality of circles partially overlapping each other on the upper surface  33 C. When the position where the laser beam L is irradiated is moved linearly at a constant rate, the brazing filler metal F appears as an elliptic or oblong shape on the upper surface  33 C. 
     Second Modified Example 
     A second modified example will be described below with reference to  FIG. 32 . Differences between the second modified example and the fourth exemplary embodiment will be mainly described, while a repeat of previous descriptions is omitted. 
     For example, as shown in  FIG. 20 , in the fourth exemplary embodiment, the two side surfaces  35 E of the wire holding body  35  are parallel to each other. 
     In contrast, in the second modified example, as shown in  FIG. 32 , the two side surfaces  35 E are inclined in such a manner that the side surfaces  35 E approach each other in a direction in which the wire holding body  35  is attached to the terminal holding body  34 . According to the above structure, the wire holding body  35  can be easily inserted between the two rear projecting portions  37  of the terminal holding body  34 . 
     Like in the second modified example, when the two side surfaces  35 E are inclined, the inner surfaces  37 A of the two rear projecting portions  37  shown in  FIG. 19  are preferably inclined in such a manner that the inner surfaces  37 A approach each other in the direction in which the wire holding body  35  is attached to the terminal holding body  34 . 
     Third Modified Example 
     A third modified example will be described below with reference to  FIG. 33 . Differences between the third modified example and the fourth exemplary embodiment will be mainly described, while a repeat of previous descriptions is omitted. 
     For example, as shown in  FIG. 20 , in the fourth exemplary embodiment, the two wire holding grooves  43  are formed in the lower surface  35 B of the wire holding body  35 , and two wires  32  are respectively attached to the two wire holding grooves  43  in the direction indicated by the arrow P. 
     In contrast, in the third modified example, as shown in  FIG. 33 , two wire holding holes  49  are formed in the wire holding body  35 , instead of forming the two wire holding grooves  43  in the wire holding body  35 . Each wire holding hole  49  extends in the front-back direction and is opened at the front surface  35 C and the back surface  35 D. Also, this structure allows the wire holding body  35  to stably hold the two wires  32 . 
     Fourth Modified Example 
     A fourth modified example will be described below with reference to  FIG. 34 . Differences between the fourth modified example and the fourth exemplary embodiment will be mainly described, while a repeat of previous descriptions is omitted. 
     For example, as shown in  FIG. 20 , in the fourth exemplary embodiment, the two wire holding grooves  43  are formed in the lower surface  35 B of the wire holding body  35 , and two wires  32  are respectively attached to the two wire holding grooves  43  in the direction indicated by the arrow P. 
     In contrast, in the fourth modified example, as shown in  FIG. 34 , the two wire holding grooves  43  are formed in the upper surface  35 A of the wire holding body  35 , and two wires  32  are respectively attached to the two wire holding grooves  43 . According to the above structure, the two wire holding grooves  43  are closed by the coupling beam  38  of the terminal holding body  34  in the state where the wire holding body  35  is attached to the terminal holding body  34 . This structure can effectively prevent each wire  32  from being removed from the corresponding wire holding groove  43 . 
     Fifth Modified Example 
     A fifth modified example will be described below with reference to  FIG. 35 . Differences between the fifth modified example and the fourth embodiment will be mainly described, while a repeat of previous descriptions is omitted. 
     For example, as shown in  FIG. 19 , in the fourth exemplary embodiment, the fixed portion  33 B is held in a cantilever manner by the terminal holding body  34 . 
     In contrast, in the fifth modified example, as shown in  FIG. 35 , the fixed portion  33 B is supported at both ends thereof by the housing S. In other words, in the fifth modified example, each terminal  33  further includes a rear held portion  33 G. The rear held portion  33 G is formed so as to extend backward from the fixed portion  33 B. The fixed portion  33 B is located between the embedded portion  33 F and the rear held portion  33 G. The rear held portion  33 G is sandwiched between the coupling beam  38  and the wire holding body  35  vertically, and thus is held by the housing S. Accordingly, the fixed portion  33 B is located between the embedded portion  33 F, which is held by the terminal holding body  34 , and the rear held portion  33 G, which is held by the housing S, so that the fixed portion  33 B is supported at both ends thereof by the housing S. In other words, the terminal  33  is supported by the housing S (fixing structure body) at two locations that sandwich the fixed portion  33 B of the terminal  33  as a portion to be connected and fixed to the conductor  41 . According to the above structure, an unintended deformation of the terminal  33  can be prevented. 
     Note that in the fifth modified example, in order to bring the fixed portion  33 B into contact with the brazing filler metal F, the terminal  33  further includes an inclined portion  33 J and an inclined portion  33 K. The inclined portion  33 J couples the fixed portion  33 B and the rear held portion  33 G together. The inclined portion  33 K couples the fixed portion  33 B and the embedded portion  33 F together. According to the presence of the inclined portion  33 J and the inclined portion  33 K, the height of the fixed portion  33 B can be freely adjusted. 
     When the laser beam L is irradiated onto the fixed portion  33 B of each terminal  33 , a support base that supports the brazing filler metal F may be placed below the brazing filler metal F. 
     Sixth Modified Example 
     A sixth modified example will be described below with reference to  FIG. 36 . Differences between the sixth modified example and the fourth embodiment are mainly described, and a repeated explanation is omitted. 
     As shown in  FIG. 36 , in the sixth modified example, when the wire holding body  35  is mated to the terminal holding body  34 , the lower surface  38 A, which is a mating surface of the terminal holding body  34  with respect to the wire holding body  35 , is inclined with respect to the lower surface  33 D in such a manner that the brazing filler metal F is pressed against the lower surface  33 D (fixed surface) of the fixed portion  33 B of the terminal  33 . According to the above structure, even if there is a slight machining error in the terminal holding body  34  or the wire holding body  35 , the terminal  33  can be reliably brought into contact with the brazing filler metal F, while the conductor  41  is subjected to a bending deformation, only by mating the wire holding body  35  and the terminal holding body  34  together. 
     From the invention thus described, it will be obvious that the embodiments of the invention may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended for inclusion within the scope of the following claims.