Abstract:
A circuit board have a first face and a second face which is opposite to the first face. The circuit board is formed with a through hole connecting the first face and the second face. A connector have an insulative casing body, a conductive lead portion projected from the casing body, and a connecting portion adapted to be connected with a wire harness. The connector is fixed to the circuit board such that a part of the casing body is located within the through hole, and the connecting portion is located in a side of the second face.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     This invention relates to a structure and a method for connecting a circuit board on which electronic elements are to be mounted to a connector which is mounted on the circuit board, and more particularly to a structure of and a method for connecting a circuit board to a surface mounting type connector. The invention also relates to a recording apparatus provided with the structure for connecting the circuit board to the surface mounting type connector.  
         [0002]     Like ordinary electronic equipments, for example, a recording apparatus, represented by an ink jet printer, employs many and various electronic elements, and these electronic elements are mounted on a plurality of printed circuit boards (hereinafter referred to as “circuit board”) each having circuits formed thereon. For electrically connecting the circuit boards together and for electrically connecting the circuit board to other electronic/electrical elements or the like, a flexible flat cable (hereinafter referred to as “FFC”) is used. The flexible flat cable is formed by a method in which a plurality of metallic conductors are arranged parallel to each other, and then are sandwiched by laminate films from both faces.  
         [0003]     When this FFC is to be connected to the circuit board, this connection is usually carried out via a connector mounted on the circuit board. Namely, a distal end (end portion) of the FFC, at which the metallic conductors are exposed is inserted into a inlet of the connector, thereby the FFC is electrically connected to the circuit board.  
         [0004]     One example of such connectors for connecting the circuit board to the FFC is a through-hole mounting type connector in which lead portions (conductive portions) of the connector are inserted into respective through holes formed through the circuit board. This through-hole mounting type connector is disclosed, for example, in Japanese Patent Publication No. 10-284196A. For electrical connection of the through-hole mounting type connector and electronic elements, the electronic element is mounted on a mounting face of the circuit board, and its lead portions are inserted into respective through holes in the circuit board and thereafter soldered on a reverse face of the mounting face of the circuit board. At this time, for example, a flow process is used as this soldering process. The flow process (flow soldering process) is used for soldering the electronic element. In this flow process, flux is coated on a soldering face so as to enhance solderability, and thereafter the soldering face of the circuit board is brought into contact with flowing molten solder, thereby effecting the soldering.  
         [0005]     Another example is a surface mounting type connector in which lead portions (conductive portions) of the connector are connected respectively to conductive pads (or lands) formed on a mounting face of a circuit board. This surface mounting type connector is disclosed, for example, in Japanese Patent Publication No. 11-195869A. For electrical connection of the surface mounting type connector and electronic elements, the electronic element is mounted on a mounting face of the circuit board, and thereafter the mounting face is soldered by a reflow process. The reflow process (reflow soldering process) is used for soldering the electronic element. In this reflow process, paste-like solder is coated on the mounting face of the circuit board, and thereafter the whole of the circuit board, having the electronic elements mounted thereon, is heated within a heating furnace, thereby effecting the soldering.  
         [0006]     In Japanese Patent Publication No. 10-284196A, the through-hole mounting type connector (particularly a connector  12  shown in  FIGS. 1, 2  and  7  of this publication) is mounted on the circuit board which is a double-sided board, and further various through-hole mounting type electronic elements are mounted on both sides (faces) of this circuit board. The double-sided board is the type of circuit board in which electric circuits are formed on both sides (faces) of this circuit board. Another example of circuit boards is a single-sided board in which electric circuits are formed on only one side of the circuit board. In some cases as in the above Patent Literature of Japanese Patent Publication No. 10-284196A, the connector is mounted on the reverse face of the mounting face of the circuit board on which many elements are mounted, so that the FFC can be easily inserted into and withdrawn from the connector.  
         [0007]     For example, when the connector is to be mounted on the reverse face of the single-sided board, the through-hole mounting type connector can be fixed to the circuit board at the reverse face side thereof, and is thus mounted on the circuit board as disclosed in Japanese Patent Publication No. 10-284196A. Namely, the conductive portions of the through-hole mounting type connector are inserted into the respective through holes from the reverse face side of the circuit board, and then the conductive portions are soldered to the respective through holes at the mounting face side of the circuit board. However, the conductive portions of the through-hole mounting type connector are soldered to the through holes by a manual soldering or by a partial-flow process using a special jig. And besides, the electronic elements are mounted on the mounting face of the single-sided board, and therefore a reflow process for soldering these electronic elements need to be carried out separately. Namely, in such a single-sided board, the two separate soldering processes, that is, the reflow soldering process for soldering the electronic elements and the soldering process for soldering the through-hole mounting type connector, need to be carried out, and therefore the process of mounting the connector, the elements, etc., on the circuit board becomes complicated, so that the production cost increases.  
         [0008]     Japanese Patent Publication No. 11-195869A discloses a structure of combining an electronic element (connector) and a circuit board together, which is characterized in that part of the connector (surface mounting type connector) is fitted or received in a through hole, formed through the circuit board, in order to reduce a height of the connector projecting from the circuit board. However, in the surface mounting type connector described in Japanese Patent Publication No. 11-195869A, an inlet for receiving a distal end of an FFC is formed in a side face of this connector disposed at a mounting face side of the circuit board, and therefore this surface mounting type connector is different from the type of connector which is disposed at a reverse face of a circuit board.  
       SUMMARY OF THE INVENTION  
       [0009]     It is therefore an object of the invention to provide a structure of and a method for connecting a circuit board to a surface mounting type connector, in which steps of a process for mounting elements on the circuit board can be reduced, thereby reducing a production cost.  
         [0010]     It is also an object of the invention to provide a recording apparatus provided with such a connecting structure.  
         [0011]     In order to attain the above described object, according to the invention, there is provided a connecting structure, comprising:  
         [0012]     a circuit board having a first face and a second face which is opposite to the first face, the circuit board being formed with a through hole connecting the first face and the second face; and  
         [0013]     a connector having an insulative casing body, a conductive lead portion projected from the casing body, and a connecting portion adapted to be connected with a wire harness, the connector being fixed to the circuit board such that a part of the casing body is located within the through hole, and the connecting portion is located in a side of the second face.  
         [0014]     A connecting structure may further comprise a conductive pad provided on the first face,  
         [0015]     wherein at least a part of the lead portion is located and soldered on the conductive pad.  
         [0016]     A connecting structure may further comprise an electronic element disposed on the first surface and electrically connected to the conductive pad.  
         [0017]     According to the invention, the connector can be soldered by reflow soldering process. Therefore, the steps of the process for mounting the elements on the circuit board can be reduced, and the production cost can be reduced. The wire harness can be easily inserted into and withdrawn from the connecting portion of the connector. The connector is held in the through hole so that the connector can be stably fixed to the circuit board. The conductive lead portion of the connector can be positively electrically connected to the conductive pad of the circuit board, respectively.  
         [0018]     According to the invention, there is also provided an apparatus, comprising:  
         [0019]     a circuit board having a first face and a second face which is opposite to the first face, the circuit board being formed with a through hole connecting the first face and the second face;  
         [0020]     a connector having an insulative casing body, a conductive lead portion projected from the casing body, and a connecting portion, the connector being fixed to the circuit board such that a part of the casing body is located within the through hole, and the connecting portion is located in a side of the second face; and  
         [0021]     a wire harness, connected to the connecting portion.  
         [0022]     Therefore, the apparatus which achieves the above advantageous effects can be provided.  
         [0023]     According to the invention, there is also provided a method of manufacturing a connecting structure, comprising:  
         [0024]     providing a circuit board having a first face on which a conductive pad is provided and a second face which is opposite to the first face, the circuit board being formed with a through hole connecting the first face and the second face;  
         [0025]     providing a connector having an insulative casing body, a conductive lead portion projected from the casing body, and a connecting portion adapted to be connected with a wire harness;  
         [0026]     inserting the connector into the through hole from a side of the first face so that a part of the casing body is located within the through hole and the connecting portion is located in a side of the second face; and bringing the lead portion into contact with the conductive pad.  
         [0027]     The connecting method may further comprise soldering the lead portion to the conductive pad by reflow soldering process.  
         [0028]     The connecting method may further comprise disposing an electronic element on the first face; and  
         [0029]     electrically connecting the electronic element to the conductive pad by the reflow soldering process.  
         [0030]     With this method, the connector can be soldered by the reflow soldering process, and therefore the steps of the process for mounting the elements on the circuit board can be reduced, and the production cost can be reduced. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0031]     The above objects and advantages of the present invention will become more apparent by describing in detail preferred exemplary embodiments thereof with reference to the accompanying drawings, wherein:  
         [0032]      FIG. 1  is a perspective view of a recording apparatus according to one embodiment of the present invention;  
         [0033]      FIG. 2  is a perspective view of an internal structure of the recording apparatus showing a state that a scanner unit is removed;  
         [0034]      FIG. 3  is section view showing a part of the recording apparatus;  
         [0035]      FIG. 4  is a perspective view of the recording apparatus showing a state that an outer housing is removed;  
         [0036]      FIG. 5  is a plan view of an operating board incorporated in the recording apparatus;  
         [0037]      FIG. 6A  is a plan view of a surface mounting type connector mounted on the operating board;  
         [0038]      FIG. 6B  is a side view of the surface mounting type connector;  
         [0039]      FIG. 6C  is a cross section view along the line VIC-VIC of  FIG. 6B ;.  
         [0040]      FIG. 7  is a side view as seen in a direction of arrow VII of  FIG. 5  showing a structure for connecting the operating board to the surface mounting type connector;  
         [0041]      FIG. 8  is a flow chart showing a process for mounting the surface mounting type connector and electronic elements on the operating board;  
         [0042]      FIG. 9  is a plan view showing a related-art operating board;  
         [0043]      FIG. 10  is a side view as seen in a direction of arrow X of  FIG. 9  showing a structure for connecting the related-art operating board to a related-art through-hole mounting type connector. 
     
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
       [0044]     Embodiments of the invention will be described with reference to the accompanying drawings. More specifically, the structure for connecting the circuit board and the surface mounting type connector together which are used in an ink jet printer (which is one of recording apparatuses) will be described. The embodiment described below will not limit the scope of the appended claims, and also all of features, combined together in the embodiment, are not always essential to the solution of the problems.  
         [0045]     As shown in  FIG. 1 , a recording apparatus  1  is a hybrid machine having a scanning function and a printing function. The recording apparatus  1  comprises an apparatus body  3  operable to perform the printing function, a scanner unit  5  operable to perform the scanning function, and is mounted on an upper side of an apparatus body  3 , and a feeder  7  provided at a rear side of the scanner unit  5 .  
         [0046]     The apparatus body  3  has an ejected sheet receptacle  9  for receiving ejected recording sheet is provided at the front side of this apparatus body  3 . When the printing function is effected, the ejected sheet receptacle  9  is pulled forward (in a direction of arrow A in  FIG. 1 ) to be pivoted about 90 degrees so as to receive the ejected recording sheet.  
         [0047]     An control panel  11  is provided at a left side portion of an upper face of the recording apparatus  1 . The scanning function executed by the scanning unit  5 , the recording function and a function of recording a scanned image and other functions executed in the apparatus body  3 , can be operated by this control panel  11 .  
         [0048]     The scanner unit  5  includes a lid  15  which can be pivoted upwardly (that is, in a direction of arrow B in  FIG. 1 ) about a pivot shaft (not shown), provided at the rear side, into an open position, and a glass table (not shown) on which a printed matter or the like to be scanned is placed is provided under the lid  15 . Further, a reading head  69  (see  FIG. 4 ) is provided under the glass support face. The whole of the scanner unit  5  can be pivoted upwardly (that is, in the direction of arrow B in  FIG. 1 ) about a pivot shaft  17  so as to open the upper side of the apparatus body  3  so that a maintenance work for internal mechanisms (including a carriage) can be easily carried out.  
         [0049]     As shown in  FIG. 1 , the feeder  7 , when not in use, is closed by a feed cover  19 . When the feed cover  19  is pivoted rearwardly, the feeder  7  is opened as shown in  FIG. 2 , and the feed cover  19  is fixed in a condition inclined at a predetermined angle so as to serve as a medium support.  
         [0050]     Card slots  13   a,    13   b  and  13   c  are provided in a left side portion of the front face of the recording apparatus  1 , and storage media (card-type semiconductor memories) which are not shown can be removably inserted into the card slots, respectively. The recording apparatus  1  can read image data directly from each of the storage media, and can form recording data so that recording can be made on the recording sheets based on these recording data.  
         [0051]     As shown in  FIG. 2 , a fixed edge guide  25  for guiding side edges of recording sheets P (serving as the recording sheet) and a movable edge guide  25  for guiding side edges of the recording sheets P are provided below the feed cover  19  also serving as the medium support, and the movable edge guide  25  can be moved in accordance with the width of the recording sheet P. When the feed cover  19  is in an open condition, a feeding port  27  (see  FIG. 2 ) is formed at the feeder  7 , and the recording sheets P, received in the feeding port  27 , are fed one by one from this feeding port  27  to the recording portion by a feed mechanism (not shown).  
         [0052]     As shown in  FIG. 3 , the recording apparatus  1  includes an internal construction provided in the vicinities of a feeding path along which the recording sheet P is fed from a left side to a right side. The recording sheet P, fed from the feeder  7 , reaches a conveyance roller  33  comprising an drive roller  29  and a follower roller  31  (which is freely rotatable). Then, the recording sheet P, while precisely fed by a drive source (not shown) during a recording process, is conveyed toward a recording head  35  located downstream of the conveyance roller  33 .  
         [0053]     The recording head  35  is supported on a carriage  37 , and the carriage  37  can be reciprocally moved in a primary scanning direction perpendicular to the transporting direction of the recording sheet P. The carriage  37  is provided with independent ink cartridges  34  (see  FIGS. 2 and 4 ) holding different color ink, respectively, and the ink can be supplied from the ink cartridges  34  to the recording head  35 .  
         [0054]     A platen unit  40  is provided in a position opposed to the recording head  35 , and ribs  39   a,    39   b  and  39   c  are formed on that side of the platen unit  40  opposed to the recording head  35 . When recording is to be made on the recording sheet P by the recording head  35 , the ribs  39   a,    39   b  and  39   c  support the recording sheet P from the lower side thereof, and form a gap (hereinafter referred to as “platen gap PG”) between the recording sheet P and the recording head  35 .  
         [0055]     The medium gap PG can be suitably adjusted in accordance with the thickness of the recording sheet P. In a properly-adjusted condition of the medium gap PG, the recording sheet P smoothly passes over the ribs  39   a,    39   b  and  39   c,  and high-quality recording is made on this recording sheet P. The recording sheets P, recorded by the recording head  35 , are sequentially ejected by an ejecting roller  41 .  
         [0056]     The ejecting roller  41  comprises a drive roller  43 , and an follower roller (spur roller)  45  which is freely rotatably supported on a “ejector frame”  44  through a holder  45   a.  The recording sheet P, held by the ejecting roller  41  (the drive roller  43  and the follower roller  45 ), is drawn and conveyed by the rotation of these rollers. A medium holding roller  47  for limiting the lifting of a trailing end of the recording sheet P is provided an upstream end portion of the ejecting frame  44  relative to the sheet transporting direction through a holder  47   a,  and is disposed between the recording head  35  and the ejecting roller  41 . In this embodiment, the ejecting frame  44  is formed by a metal plate.  
         [0057]     As shown in  FIG. 3 , the platen unit  40  comprises a first guide member  49  and a second guide member  51  which are connected together. In other words, the platen unit  40  is divided into the first guide member  49  and the second guide member  51 , and the first guide member  49  can be pivoted about a pivot shaft  49   a  while the second guide member  51  can be pivoted about a drive roller shaft  43   a.  With this construction, the ribs  39   a,    39   b  and  39   c,  formed on the platen unit  40 , can be moved toward and away from the recording head  35  so as to adjust the medium gap PG.  
         [0058]     Next, a base body (frame) of the recording apparatus  1  will be described with reference to  FIG. 2 . As shown in  FIG. 2 , the base body of the recording apparatus  1  comprises a main frame  59  extending in the primary scanning direction (and disposed parallel to a vertical plane), and a first side frame  61  and a second side frame  63  which are integrally formed respectively at opposite ends of the main frame  59  and are extending perpendicularly to the main frame  59 .  
         [0059]     A carriage guide shaft  38  is supported on and extend between the first and second side frames  61  and  63 , and the carriage  37  is guided in the primary scanning direction by the carriage guide shaft  38 . A cap unit  55  is provided in the vicinity of the second side frame  63 , and is disposed beneath a path of reciprocal movement of the carriage  37 . The recording head  35  ( FIG. 3 ) is sealed by the cap unit  55 , so that the clogging of nozzle orifice is prevented. When a negative pressure is applied to ink nozzles from a pump unit (not shown), the ink are ejected from the respective nozzle orifice, thereby recovering an ejectability for eliminating the clogging by the ink.  
         [0060]     The drive roller  29  (see  FIG. 3 ) is in the form of a shaft member extending in the primary scanning direction, and one end  29   a  (see  FIG. 4 ) thereof is supported on the first side frame  61  (forming a frame face) extending perpendicularly to an axis of rotation of the drive roller  29 , while the other end thereof is supported on an auxiliary frame (not shown) provided between the first side frame  61  and the second side frame  63 .  
         [0061]     The carriage  37  is fixed to a part of an endless belt  48  (see  FIGS. 2 and 4 ) stretched by a drive pulley (not shown) provided on a carriage motor  89  (shown in  FIG. 4 ), and a follower pulley. The carriage  37  is driven by the carriage motor  89  (see  FIG. 4 ) to be reciprocally moved in the primary scanning direction.  
         [0062]     Next, a positional relation between the reading head  69  which is a constituent element of the scanner unit  5 , a flexible flat cable (hereinafter referred to as “FFC”)  71  connecting a main board  65  to the reading head  69 , and other constituent elements of the recording apparatus  1  will be described. As shown in  FIG. 4 , the reading head  69  is disposed in a home position (shown in  FIG. 4 ) in the vicinity of the first side frame  61 , and can be reciprocally moved in the primary scanning direction as well as the carriage  37 . The FFC  71  extends from the main board  65  (disposed in the vicinity of the home position of the reading head  69 ) toward the second side frame  63 , and then is folded back assuming a substantially U-shape, and is connected to the reading head  69 . The FFC  71  can be deformed, following the reciprocal movement of the reading head  69 .  
         [0063]     Next, the main board  65  and an operating board  110  will be described. As shown in  FIG. 4 , the main board  65  is disposed adjacent to an outer side of the first side frame  61  and extends substantially parallel to the first side frame  61 . As shown in  FIG. 2 , the main board  65  covered with a shield cover  67  is mounted on the recording apparatus  1 . As shown in  FIG. 4 , the card slots  13   a,    13   b  and  13   c  are provided on the main board  65  so as to face the front side of the recording apparatus  1 , and a USB slot  87  for connection to an external equipment (for example, such as a host computer) is provided on the main board  65  so as to face the rear side of the recording apparatus  1 . The operating board  110 , forming the control panel  11 , is provided on the main board  65  so as to face the upper side of the recording apparatus  1 .  
         [0064]     As shown in  FIG. 4 , electronic elements (including various switches), forming the control panel  11 , are surface-mounted on an operating board  110  (that is, on a mounting face  110   a  described later). The operating board  110  is connected to the main board  65  via a surface mounting type connector  120  and a harness  130  comprising an FFC, and electrical signals are communicated between the operating board  110  and the main board  65 .  
         [0065]     In the operating board  110  of this embodiment, the various electronic elements are surface-mounted on the mounting face  110   a,  and therefore in order to facilitate the insertion and withdrawal of the harness  130  and also to reduce the length of the harness  130  so as to reduce adverse effects of noises, the harness  130  is provided at a reverse face ( 110   b ) side (see  FIG. 7 ) of the operating board  110 . Namely, the surface mounting type connector  120  is mounted on the operating board  110  in such a manner that this connector  120  is fitted in a through hole  111  (see  FIG. 5 ) formed through the operating board  110 , so that the harness  130  can be inserted into and withdrawn from the connector  120  at the reverse face ( 110   b ) side of the operating board  110 .  
         [0066]     Next, the structure of the invention for connecting the circuit board (the operating board  110 ) to the surface mounting type connector  120  will be described in detail with reference to FIGS.  5  to  10 .  
         [0067]     As shown in  FIG. 5 , the through hole  11  of a rectangular shape is formed through a lower right corner portion of the operating board  110  of this embodiment. Lands (conductive pads)  112   a  and  112   b  are formed on that portion of the operating board  110  disposed around the through hole  111  (particularly those portions disposed immediately adjacent respectively to upper and lower edges of the through hole  111  in  FIG. 5 ), and these lands  112   a  and  112   b  are so arranged as to be held in good contact with lead portions  121   a  and  121   b  (see  FIG. 6 ) of the surface mounting type connector  120  (hereinafter, simply referred to as “connector  120 ”), respectively. As shown in  FIG. 4 , the operating board  110  of this embodiment is a single-sided board. An upper face of the operating board  110  defines the mounting face  110   a  on which the electronic elements are to be surface-mounted. Electric circuits are formed only on the mounting face  110   a.  In  FIG. 5 , the electric circuits, formed by conductors, are omitted.  
         [0068]     As shown in  FIGS. 6A, 6B  and  6 C, the connector  120  has a substantially rectangular parallelepiped shape, and the lead portions  121   a  and  121   b  extend from a lower end thereof in a horizontal direction (that is, in a direction parallel to each of upper and bottom faces of the connector  120 ). An inlet  123  is formed in an upper portion (in  FIG. 6 ) of the connector  120 . A distal end (end portion) of the harness  130  (at which center conductors  130   a  are exposed) is inserted into this inlet  123  from the upper side as shown in  FIG. 6C , so that the harness  130  is connected to the connector  120 . In  FIG. 6C , the direction inserting of the harness  130  is indicated by arrow D (This is the same with  FIGS. 7 and 10 .).  
         [0069]     As shown in  FIG. 7 , the connector  120  is fitted into the through hole  111  of the operating board  110  from the mounting face  110   a  side in such a condition that the inlet  123  is faces downward, while the lead portions  121   a  and  121   b  are faces upward (The direction of fitting of the connector  120  is indicated by arrow F.). The lead portions  121   a  and  121   b  of the connector  120  are so disposed as to be opposed respectively to the lands  112   a  and  112   b  of the operating board  110 , and therefore when the connector  120  is fitted into the through hole  111 , the lead portions  121   a  and  121   b  of the connector  120  are positively brought into contact with the lands  112   a  and  112   b  of the operating board  111 .  
         [0070]     Normally, the connector  120  is mounted on a circuit board in such a condition (hereinafter referred to as “normal condition”) that the inlet  123  is provided on the upper side, while the lead portions  121   a  and  121   b  are provided on the lower side, and thereafter this connector  120  is surface-mounted on the circuit board by soldering by a reflow process (described later). On the other hand, in the connecting structure of the invention, the connector  120  is fitted into the through hole  111  (formed through the operating board  110 ) in its reversed condition (hereinafter referred to as “reversed condition”), and the connector  120  is mounted on the operating board  110 . At this time, the lead portions  121   a  and  121   b  of the connector  120  can be soldered respectively to the lands  112   a  and  112   b  of the operating board  110  according to the reflow process (reflow soldering process).  
         [0071]     Here, the soldering process by the reflow process will be described. As described above, the reflow process (reflow soldering process) is used for soldering electronic elements including the connector  120 . In this reflow process, paste-like solder is coated on the mounting face  110   a  of the operating board  110 , and thereafter the whole of the operating board  110  is heated, thereby effecting the soldering. The process for mounting the connector  120  and the other electronic elements on the operating board  110  by the reflow process will be described with reference to  FIG. 8 .  
         [0072]     First, a metal mask is put on the mounting face  110   a  of the operating board  110  (to which soldering is applied) to cover the same (Step S 11 ). For example, a stainless steel mask, having holes arranged in a solder-coating pattern, is used as this metal mask.  
         [0073]     Then, paste-like solder is coated on the mounting face  110   a  by a screen printing method (Step S 12 ). Namely, in Step S 11 , the metal mask has been placed on the mounting face  110   a  to cover the same, and therefore the paste-like solder is coated on the mounting face  110   a  in a pattern corresponding to the solder-coating pattern of the holes of the metal mask. At this time, the paste-like solder is coated on the lands  112   a  and  112   b.    
         [0074]     Then, the connector  120  is fitted into the through hole  111  in the operating board  110 , and is fixed to the operating board  110  as described above, and also the other electronic elements are mounted on the mounting face  110   a  (Step S 13 ).  
         [0075]     Then, the whole of the operating board  110 , having the connector  120  and the electronic elements mounted thereon, is heated in a reflow facility, and as a result the paste-like solder is melted, thereby the soldering process applied to the operating board  110  is completed (Step S 14 ). At this time, the solder, coated on the lands  112   a  and  112   b,  is melted, and then is solidified, thus the soldering of the lead portions  121   a  and  121   b  are completely soldered to the respective lands  112   a  and  112   b.    
         [0076]     Thus, in the structure of the invention for connecting the operating board  110  to the connector  120 , the harness  130  can be inserted into and withdrawn from the connector  120  at the reverse face  110   b  of the operating board  110 , and besides the connector  120  can be satisfactorily connected to the operating board  110  by the reflow process.  
         [0077]     Next, the advantageous effects of the invention will be described, comparing the connecting structure of the invention with a related-art structure (comparative example) for connecting a circuit board and a connector which are shown in  FIGS. 9 and 10 .  
         [0078]     As shown in  FIGS. 9 and 10 , a plurality of through holes  211  for the mounting of a through-hole mounting type connector  220  (hereinafter simply referred to as “connector  220 ″ are formed through a lower right corner portion of the operating board  210 . A face of each through hole  211  is covered with a conductor connected to an electric circuit formed on the operating board  210 . The operating board  210  (comparative example) is a single-sided board similar to the operating board  110  except that the plurality of through holes  211  are provided in place of the through hole  11 , and the electric circuits are formed only on a mounting face  210   a  of the operating board  210 .  
         [0079]     As shown in  FIG. 10 , in the related-art connecting structure, the connector  220  is first located on a reverse face  210   b  of the operating board  210 , and then lead portions  221  of the connector  220  are inserted respectively into the through holes  211 , and the lead portions  221  are soldered respectively to the through holes  211 , thereby mounting the connector  220  on the operating board  210 . The connector  220  has been mounted on the reverse face  210   b  of the operating board  210  (which is the single-sided board in which the electric circuits are formed only on the mounting face  210   a  of the operating board  210  as described above)so as to enable the insertion and withdrawal of the harness  130  at the reverse face  210   b  of the operating board  210  while ensuring the electrical connection of the connector  220  to the electric circuits.  
         [0080]     In this related-art connecting structure, however, it is necessary to electrically connect the lead portions  221  to the respective through holes  211  by a soldering process applied to the mounting face  210   a  of the operating board  210 . And besides, in this soldering process, the soldering need to be carried out manually or by a flow process using a predetermined jig or the like. Therefore, the process of mounting the through-hole mounting type connector  210  and other electronic elements on the operating board  210  has been complicated. Namely, in the process of mounting the connector  220  and other electronic elements on the operating board  210 , first, the electronic elements are surface-mounted on the mounting face  210   a  by the reflow soldering process, and then the connector  220  is fixed to the reverse face  210   b,  and the lead portions  221  are separately soldered to the respective through holes  211 . Thus, in the related-art connecting structure, the two separate soldering processes need to be carried out, and therefore the process of mounting the through-hole mounting type connector and other electronic elements on the operating board  210  becomes complicated.  
         [0081]     On the other hand, in the connecting structure of the invention for connecting the operating board  110  to the connector  120 , the connector  120  is fitted into the through hole  111  of the operating board  110  in the direction of arrow F from the mounting face  110   a,  and is fixed to the operating board  110 , with the inlet  123  directed to the reverse face  110   b  as shown in  FIG. 7 . With this construction, the harness  130  can be easily inserted into and withdrawn from the connector  120  at the reverse face  110   b  of the operating board  110 . And besides, the length of the harness  130  can be reduced, and therefore adverse effects of noises on the harness  130  can be reduced. Further, the lead portions  121   a  and  121   b  of the connector  120  can be satisfactorily brought into contact with the lands  121   a  and  121   b  connected to the electric circuits formed on the operating board  110 , and therefore the soldering of the lead portions  121   a  and  121   b  to the respective lands  112   a  and  112   b  can be carried out simultaneously with the soldering of the other electronic elements by the reflow soldering process. Namely, the two separate soldering processes, carried out in the related-art connecting structure, can be replaced by one reflow soldering process, and therefore the steps of the process for mounting the connector  120  and the other electronic elements can be reduced. As a result, time required for mounting the surface mounting type connector and other electronic elements on the circuit board, as well as the production cost, can be reduced.  
         [0082]     Next, other advantages of the structure of the invention for connecting the operating board  110  to the connector  120  will be described. In  FIGS. 7 and 10 , the thickness of each of the operating boards  110  and  210  is denoted by T, and the height of each of the connector  120  and the connector  220  is denoted by H.  
         [0083]     When the related-art connector  220 , having the height H, is mounted on the operating board  210  as shown  20  in  FIG. 10 , the connector  220  projects downwardly from the reverse face  210   b  of the operating board  210  by an amount equal to the height H. On the other hand, in the structure of the invention for connecting the operating board  110  to the connector  120 , even if the connector  110 , having the same height H, is mounted on the operating board  110 , the height (or amount) of projecting of the connector  110  from the reverse face  110   a  of the operating board  110  is (H-T), and thus the height can be reduced by an amount equal to the thickness T of the operating board  110 . Namely, when a sufficient mounting space is not available on the circuit board in the height direction (the upward-downward direction), the structure of the invention is capable of reducing the projecting height of the connector.  
         [0084]     With this construction, the inlet  123  of the connector  120  can be disposed at the reverse face  110   b  of the mounting face  110   a  of the operating board  110 , and besides the connector  120  can be soldered by the reflow soldering process. As a result, the cable (harness  130 ) can be easily inserted into and withdrawn from the connector  120 , and the steps of the process for mounting the elements on the operating board  110  can be reduced, and the production cost can be reduced.  
         [0085]     Since the size of the through hole  111  is adjusted so that the connector  120  can be fixed to the operating board  110 , the connector  120  is held in the through hole  111 , and therefore the connector  120  can be stably fixed to the operating board  110 .  
         [0086]     Since the connector  120  is fitted into the through hole  111  so that the lead portions (conductive portions)  121   a  and  121   b  of the connector  120  are brought into contact respectively with the lands (conductive pads)  112   a  and  112   b  formed on the mounting face  110   a,  the lead portions  121   a  and  121   b  of the connector  120  can be positively electrically connected to the lands  112   a  and  112   b  of the operating board  110 , respectively.  
         [0087]     Since the connector  120  can be soldered by the reflow soldering process, the steps of the process for mounting the elements on the operating board  110  can be reduced, and the production cost can be reduced.  
         [0088]     The present invention is not limited to the above embodiment, and can be applied to any other suitable embodiment in so far as such embodiment does not depart from the scope of the appended claims. For example, although the above embodiment of the invention is directed to the structure and method for connecting the operating board  110  to the connector  120 , the invention is applicable to any circuit board, having electronic elements mounted thereon, is connected to a surface mounting type connector mounted on the circuit board.  
         [0089]     The invention can be applied not only to the ink jet printer but also to any other suitable recording apparatus in so far as such recording apparatus is incorporating a structure for connecting a circuit board to a surface mounting type connector. Furthermore, the invention is not limited to the recording apparatus, but can be applied to other electrical and electronic equipments.