Abstract:
A method is disclosed for performing rework soldering for removing an electronic component from a printed circuit board and re-soldering the electronic component to the printed circuit board. The method includes the steps of positioning a dual structure body including a heating member and a cooling member between a rework target and a non-rework target placed on the printed circuit board, the heating member and the cooling member being arranged facing each other with a slight space provided therebetween, the heating member being situated toward the rework target, the cooling member being situated toward the non-rework target; heating the heating member; and cooling the cooling member.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2008-137150 filed on May 26, 2008, the entire contents of which are incorporated herein by reference. 
       FIELD 
       [0002]    The embodiments discussed herein are related to a method and an apparatus for rework soldering. For example, a method and apparatus for performing reflow soldering or rework soldering. 
       BACKGROUND 
       [0003]    Newly developed high performance LSIs (Large Scale Integrated Circuit) using, for example, BGA (Ball Grid Array) are widely used by communication devices and information devices. Electric connection failure with respect to a printed circuit board on which a BGA electronic component is mounted, is in many cases, found for the first time during a testing phase after the BGA electronic component is mounted on the printed circuit board. Since the printed circuit boards are relatively expensive, a reworking (replacing) operation is performed on the BGA electronic component for resolving the connection failure. 
         [0004]    In recent years, lead free solder has been promoted in view of environmental protection. Due to the transition from tin/lead eutectic solder to lead free solder, it is becoming difficult to perform rework soldering where solder bumps of a BGA electronic component are thermally melted for reworking. This is because the melting point of lead free solder (for example, approximately 217° C.) is higher than the melting point of tin/lead eutectic solder (approximately 183° C.). 
         [0005]    Furthermore, although increase in the size of electronic components and decrease of space between electronic components (e.g., space no greater than 2 mm) are progressing due to demands for more functions to be provided by an electronic apparatus, improvement of heat resistance of the electronic apparatus is unlikely. Therefore, controlling the temperature at spaces between electronic components is one important aspect. In one example of controlling the temperature in a rework soldering process, the temperature of the electronic component to be replaced is set to be no less than the minimum soldering temperature (e.g., 230° C.) and the temperature of the component (peripheral component) which is not to be replaced is set to be no greater than the heat resistance temperature (e.g., 170° C.) of the peripheral component. 
         [0006]      FIG. 1  illustrates a side view of a rework soldering apparatus according to a related art example. In  FIG. 1 , an electronic component (rework target)  1  and bumps  1   a  of the electronic component  1  are heated by blowing warm air from a warm air nozzle  2  positioned above the electronic component  1  (see arrows in  FIG. 1 ). Further, the bumps  1   a  are also heated via a printed circuit board  3  by blowing warm air from a warm air nozzle  4  positioned below a lower surface of the printed circuit board  3  on which the electronic component  1  is provided. 
         [0007]    A heat insulating material  6  is arranged between the electronic component  1  and another neighboring electronic component (peripheral component)  5  which is not subject to the reworking process, so that the warm air from the warm air nozzle  2  does not blow upon the peripheral component  5 . Further, a heat absorbing material  7  is placed into contact with the peripheral component  5  to prevent the temperatures of the peripheral component  5  and bumps  5   a  of the peripheral component  5  from increasing. 
         [0008]    For example, Japanese Laid-Open Patent Publication No. 2003-188527 discloses a method of heating a lower surface of a substrate having an electronic component mounted on an upper surface of the substrate and compulsorily cooling the upper surface with cool air. As another example, Japanese Laid-Open Patent Publication No. 61-56769 discloses a method of arranging thermal insulating materials between a pre-heating part, a main heating part, and a cooling part of a reflow furnace and thermally separating these parts from each other. 
         [0009]    As the space between the electronic component  1  and the peripheral component  5  is further reduced for achieving high density mounting, the radiant heat and the convective heat of the atmosphere and the heat conducted from the printed circuit board  3  may cause the temperature of the bumps  5   a  facing the electronic component  1  to surpass the heat resistance temperature of 170° C. when the bumps  1   a  facing the peripheral component  5  are heated to a temperature of 230° C. 
         [0010]    Further, enhancing the heat absorbing performance by cooling the heat absorbing material  7  with a cooling agent (e.g., dry ice) and compulsorily reducing the temperature of the bumps  5   a  facing the electronic component  1  may cause the temperature of the bumps  1   a  facing the peripheral component  5  to decrease and degrade solder joining of the bumps  1   a.    
       SUMMARY 
       [0011]    According to an aspect of the invention, a method for performing rework soldering for removing an electronic component from a printed circuit board and re-soldering the electronic component to the printed circuit board includes the steps of: positioning a dual structure body including a planar heating member and a cooling member between a rework target and a non-rework target placed on the printed circuit board, the heating member and the cooling member being arranged facing each other with a slight space provided therebetween, the heating member being situated toward the rework target, the cooling member being situated toward the non-rework target; heating the heating member; and cooling the cooling member. 
         [0012]    According to another aspect of the invention, an apparatus for performing rework soldering for removing an electronic component from a printed circuit board and re-soldering the electronic component to the printed circuit board includes: a dual structure body including a planar heating member and a cooling member positioned between a rework target and a non-rework target placed on the printed circuit board, the heating member and the cooling member being arranged facing each other with a slight space provided therebetween, the heating member being situated toward the rework target, the cooling member being situated toward the non-rework target. 
         [0013]    The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims. 
         [0014]    It is to be understood that both the foregoing generation description and the followed detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0015]      FIG. 1  illustrates a side view of a rework soldering apparatus according to a related art example; 
           [0016]      FIG. 2  is a side view for describing an overall configuration of a rework soldering apparatus according to an embodiment of the present invention; 
           [0017]      FIG. 3  is a side view illustrating an embodiment of a rework soldering apparatus; 
           [0018]      FIG. 4  is a cross-sectional view illustrating a part of an embodiment of a rework soldering apparatus; 
           [0019]      FIG. 5  is a perspective view illustrating an embodiment of a heating/reflecting plate; 
           [0020]      FIG. 6  is a perspective view illustrating an embodiment of a cooling plate; 
           [0021]      FIG. 7  is a perspective view illustrating a first embodiment of a dual structure body; 
           [0022]      FIG. 8  is a perspective view illustrating a second embodiment of a dual structure body; and 
           [0023]      FIG. 9  is a table for describing effects of an embodiment of the present invention. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0024]    In the following, embodiments of the present invention will be described with reference to the accompanying drawings. 
         [0025]    With the below-described embodiments of the present invention, for example, reflow soldering or rework soldering of an electronic component(s) by using lead free solder can be realized. 
       &lt;Overall Configuration of Rework Soldering Apparatus&gt; 
       [0026]      FIG. 2  is a side view for describing an overall configuration of a rework soldering apparatus according to an embodiment of the present invention. In  FIG. 2 , a BGA electronic component (a component subject to a rework/soldering process, hereinafter also referred to as “rework target”)  11  and a first BGA peripheral component (a component not subject to a rework/soldering process, hereinafter also referred to as “non-rework target”)  12  are positioned on an upper surface of a printed circuit board  10 . A second BGA peripheral component (non-rework target)  13  is positioned on a lower surface of the printed circuit board  10 . 
         [0027]    The electronic component  11  can be selectively (partially) heated from both sides of the printed circuit board  10  by, for example, warm air, infrared (IR) rays, or a heating head. 
         [0028]    On the upper surface of the printed circuit board  10 , a first dual structure  200  is positioned between a heating area for heating the electronic component  11  and a cooling area for cooling the first peripheral component  12  and has an end part contacting the upper surface of the printed circuit board  10 . The first dual structure  200  includes a first heating/reflecting plate (heating member)  14  and a first cooling plate (cooling member)  15  that are arranged facing each other with a slight space provided therebetween. On the lower surface of the printed circuit board  10 , a second dual structure  210  is positioned between the heating area for heating the electronic component  11  and a cooling area for cooling the second peripheral component  13  and has an end part contacting the lower surface of the printed circuit board  10 . The second dual structure  210  includes a second heating/reflecting plate (heating member)  16  and a second cooling plate (cooling member)  17  that are arranged facing each other with a slight space provided therebetween. 
         [0029]    The first and second heating/reflecting plates  14 ,  16  are not only configured to heat themselves but also reflect convective heat/radiant heat from the heating area. The first and second cooling plates  15 ,  17  are configured to cool themselves. By providing a space (filled with atmospheric air having low thermal conductivity) between the first heating/reflecting plate  14  and the first cooling plate  15 , the first heating/reflecting plate  14  and the first cooling plate  15  can be thermally separated from each other. Likewise, by providing a space (filled with atmospheric air having low thermal conductivity) between the second heating/reflecting plate  16  and the second cooling plate  17 , the second heating/reflecting plate  16  and the second cooling plate  17  can be thermally separated from each other. 
         [0030]    By providing the dual structures in a manner having end parts of the first and second heating reflecting plates  14 ,  16  and end parts of the first and second cooling plates  15 ,  17  contacting the printed circuit board  10 , convective heat and radiant heat from the atmosphere and thermal conduction from the printed circuit board  10  can be effectively controlled. 
       &lt;Embodiment of Rework Soldering Apparatus&gt; 
       [0031]      FIG. 3  is a side view illustrating an embodiment of a rework soldering apparatus  1000 .  FIG. 4  is a cross-sectional view illustrating a part of the embodiment of the rework soldering apparatus  1000  of  FIG. 3 . In  FIGS. 3 and 4 , a BGA electronic component (rework target)  21 , BGA peripheral components (non-rework targets)  22 ,  23 , and other components are provided on an upper surface of a printed circuit board  20 , and BGA peripheral components (non-rework targets)  25 ,  26  and other components are provided on a lower surface of the printed circuit board  20 . 
         [0032]    The electronic component  21  is partially heated by an infrared heater  27  from an upper side of the printed circuit board  20  and is entirely heated by another infrared heater  28  from a lower side of the printed circuit board  20 . 
         [0033]    A dual structure body  300 A is provided on the upper surface of the printed circuit board  20 . The dual structure body  300 A includes a heating/reflecting plate (heating member)  31  and a cooling plate (cooling member)  32  facing each other with a slight space provided therebetween. The dual structure body  300 A has end parts contacting the upper surface of the printed circuit board  20  between a heating area for heating the electronic component  21  and a cooling area for heating the peripheral component  22 . A dual structure body  300 B is provided on the upper surface of the printed circuit board  20 . The dual structure body  300 B includes a heating/reflecting plate (heating member)  33  and a cooling plate (cooling member)  34  facing each other with a slight space provided therebetween. The dual structure body  300 B has end parts contacting the upper surface of the printed circuit board  20  between a heating area for heating the electronic component  21  and a cooling area for cooling the peripheral component  23 . 
         [0034]    Further, a dual structure body  310 A is provided on the lower surface of the printed circuit board  20 . The dual structure body  310 A includes a heating/reflecting plate (heating member)  35  and a cooling plate (cooling member)  36  facing each other with a slight space provided therebetween. The dual structure body  310 A has end parts contacting the lower surface of the printed circuit board  20  between a heating area for heating the electronic component  21  and a cooling area for cooling the peripheral component  25 . A dual structure body  310 B is provided on the lower surface of the printed circuit board  20 . The dual structure body  310 B includes a heating/reflecting plate (heating member)  37  and a cooling plate (cooling member)  38  facing each other with a slight space provided therebetween. The dual structure body  310 B has end parts contacting the lower surface of the printed circuit board  20  between a heating area for heating the electronic component  21  and a cooling area for cooling the peripheral component  26 . With the dual structure bodies  300 A,  300 B,  310 A,  310 B, the spaces between the heating/reflecting plates  31 ,  33 ,  35 ,  37  and the cooling plates  32 ,  34 ,  36 ,  38  are filled with atmospheric air having low heat conductivity. 
         [0035]    Each of the heating/reflecting plates  31 ,  33 ,  35 ,  37  has one end part contacting the surface of the printed circuit board  20 . Temperature sensors  41 ,  43 ,  45 ,  47  are provided at the vicinity of corresponding end parts of the heating/reflecting plates  31 ,  33 ,  35 ,  37 . Likewise, each of the cooling plates  32 ,  34 ,  36 ,  38  has one end part contacting the surface of the printed circuit board  20 . Temperature sensors  42 ,  44 ,  46 ,  48  are provided at the vicinity of corresponding end parts of the cooling plates  32 ,  34 ,  36 ,  38 . The temperatures detected by the temperature sensors  41 - 48  are supplied to a control part  50 . 
         [0036]    Heating parts (e.g., panel heaters)  51 ,  53 ,  55 ,  57  are provided at the other end parts (distal end parts positioned apart from the surface of the printed circuit board  20 ) of the heating/reflecting plates  31 ,  33 ,  35 ,  37 . Further, cooling parts (e.g., heat releasing fins)  52 ,  54 ,  56 ,  58  are provided at the other end parts (distal end parts positioned apart from the surface of the printed circuit board  20 ) of the cooling plates  32 ,  34 ,  36 ,  38 . 
         [0037]    The control part  50  controls the temperatures of the heating parts  51 ,  53 ,  55 ,  57  separately so that each of the temperatures of the heating/reflecting plates  31 ,  33 ,  35 ,  37  detected by the temperature sensors  41 ,  43 ,  45 ,  47  becomes a predetermined temperature (e.g., no less than 230° C.). Further, the control part  50  controls the temperatures of the cooling parts  52 ,  54 ,  56 ,  58  separately so that the temperatures of the cooling plates  32 ,  34 ,  36 ,  38  detected by the temperature sensors  42 ,  44 ,  46 ,  48  become a predetermined temperature (e.g., no greater than 170° C.). It is to be noted that, in a case where heat releasing fins are used as the cooling parts  52 ,  54 ,  56 ,  58 , the control part  50  controls the temperatures of the cooling parts  52 ,  54 ,  56 ,  58  by controlling the amount of refrigerant (e.g., air, water) to be supplied to the heat releasing fins. 
         [0038]    Alternatively, one temperature sensor can be provided on each surface (upper surface and lower surface) of the printed circuit board  20  instead providing all of the temperature sensors  41 - 48  in the vicinity of the upper and lower surfaces of the printed circuit board  20 , to allow the control part  50  to control the temperatures of the heating parts  51 ,  53 ,  55 ,  57  and the cooling parts  52 ,  54 ,  56 ,  58  based on the temperatures detected by the temperature sensor provided on each surface of the printed circuit board  20 . 
         [0039]    A base/driving part  60 , which serves as a base and a driving part, includes supporting members  61 - 66 . The supporting member  61  supports the heating/reflecting plate  31  and the cooling plate  32 . The control part  50  drives the supporting member  61  to move (change position) in direction Z (thickness direction of the printed circuit board  20 ), direction X (horizontal direction in  FIG. 3 ), or direction Y (depth direction in  FIG. 3 ), to enable the end parts of the heating/reflecting plate  31  and the cooling plate  32  to contact the printed circuit board  20 . 
         [0040]    The supporting member  62  supports the heating/reflecting plate  33  and the cooling plate  34 . The control part  50  drives the supporting member  62  to move (change position) in direction Z, direction X, or direction Y, to enable the end parts of the heating/reflecting plate  33  and the cooling plate  34  to contact the printed circuit board  20 . 
         [0041]    The supporting members  63 ,  64  support the printed circuit board  20 . The control part  50  drives the printed circuit board  20  to move (change position) in direction Z, direction X, or direction Y and drives the printed circuit board  20  to rotate around the Z axis of the printed circuit board  20 . Accordingly, flexibility during selection of the electronic component  21  can be improved. 
         [0042]    The supporting member  65  supports the heating/reflecting plate  35  and the cooling plate  36 . The control part  50  drives the supporting member  62  to move (change position) in direction Z, direction X, or direction Y, to enable the end parts of the heating/reflecting plate  35  and the cooling plate  36  to contact the part of the printed circuit board  20  between the electronic component  21  and the peripheral component  25 . 
         [0043]    The supporting member  66  supports the heating/reflecting plate  37  and the cooling plate  38 . The control part  50  drives the supporting member  66  to move (change position) in direction Z, direction X, or direction Y, to enable the end parts of the heating/reflecting plate  37  and the cooling plate  38  to contact the part of the printed circuit board  20  between the electronic component  21  and the peripheral component  26 . 
         [0044]    As illustrated in  FIG. 3 , bending of the printed circuit board  20  can be prevented because the printed circuit board  20  is in a fixed position by having its upper and lower surfaces held (sandwiched) by the end parts of the heating/reflecting plates  31 ,  33 ,  35 ,  37  and the end parts of the cooling plates  32 ,  34 ,  36 ,  38 . 
       &lt;Structure of Heating/Reflecting Plate&gt; 
       [0045]      FIG. 5  is a perspective view illustrating an embodiment of a heating/reflecting plate  70  (corresponding to the heating/reflecting plate  31 ,  33 ,  35 ,  37 ). In  FIG. 5 , the heating/reflecting plate  70  includes a metal heating plate  71  and a heating plate holding member  72 . For example, a copper plate having high thermal conductivity (403 W/m·k) and a thickness of approximately 3 mm may be used as the metal heating plate  71 . Further, surface treating using, for example, gold plating may be performed on the metal heating plate  71  for restraining heat radiation and heat absorption of the metal heating plate  71 , to control the radiant heat with respect to, for example, a metal cooling plate  81  (described below) to be a minimum amount. Alternatively, other than using copper for the metal heating plate  71 , aluminum, iron, or stainless steel may also be used. 
         [0046]    A buffering member (shock absorbing member)  73  is provided at an end portion of the metal heating plate  71  contacting the printed circuit board  20 . A resin material having heat resistance and high thermal conductivity or a metal leaf spring may be used as the buffering member  73 . Thus, by having the metal heating plate  71  in firm contact with the printed circuit board  20  with the buffering member  73 , heat flow can be effectively controlled (e.g., effectively separated) and the printed circuit board  20  can be prevented from being damaged. 
         [0047]    The metal heating plate  71  is supported by the heating plate holding member  72 . The heating plate holding member  72  is supported by the supporting members  61 - 66  of the base/driving part  60 . The heating parts  51 ,  53 ,  55 ,  57  are attached to a center part  74  of the heating plate holding member  72  for heating the metal heating plate  71 . It is to be noted that, the metal heating plate  71  and the heating plate holding member  72  may be formed as a united body (integrally formed) and a heat pipe may be used to heat the united body. 
       &lt;Structure of Cooling Plate&gt; 
       [0048]      FIG. 6  is a perspective view illustrating an embodiment of a cooling plate  80  (corresponding to the cooling plates  32 ,  34 ,  36 ,  38 ). In  FIG. 6 , the cooling plate  80  includes a metal cooling plate  81  and a cooling plate holding member  82 . For example, a copper plate having a high thermal conductivity (403 W/m·k) and a thickness of approximately 3 mm may be used as the metal cooling plate  81 . Further, surface treating using, for example, gold plating may be performed on the metal cooling plate  81  for restraining heat radiation to and heat absorption by the metal cooling plate  81 , to thereby control the radiant heat absorbed with respect to, for example, the metal heating plate  71  to be a minimum amount. Alternatively, other than using copper for the metal cooling plate  81 , aluminum, iron, or stainless steel may also be used. 
         [0049]    A buffering member (shock absorbing member)  83  is provided at an end portion of the metal cooling plate  81  contacting the printed circuit board  20 . A resin material having heat resistance and high thermal conductivity or a metal leaf spring may be used as the buffering member  83 . Thus, by having the end portion of the metal cooling plate  81  in firm contact with the printed circuit board  20  with the buffering member  83 , heat flow can be effectively controlled (e.g., effectively separated) and the printed circuit board  20  can be prevented from being damaged. 
         [0050]    The metal cooling plate  81  is supported by the cooling plate holding member  82 . The cooling plate holding member  82  is supported by the supporting members  61 - 66  of the base/driving part  60 . A cooling part (corresponding to the cooling part  52 ,  54 ,  56 ,  58 ) is attached to the cooling plate holding member  82  for cooling the metal cooling plate  81 . It is to be noted that, the metal cooling plate  81  and the cooling plate holding member  82  may be formed as a united body (integrally formed) and a heat pipe may be used to cool the united body. 
       &lt;First Embodiment of Dual Structure Body&gt; 
       [0051]      FIG. 7  is a perspective view for describing a first embodiment of a dual structure body having the heating/reflecting plate  70  of  FIG. 5  and the cooling plate  80  of  FIG. 6  assembled together.  FIG. 7  illustrates a dual structure body  90 A having the heating/reflecting plate  70  and the cooling plate  80  supported and fixed to each other by supporting members  91 ,  92  in a manner where the supporting members  91 ,  92  are interposed between the heating/reflecting plate  70  and the cooling plate  80 . The supporting members  91 ,  92  are formed of a heat insulating material such as ceramic. By positioning the heating/reflecting plate  70  and the cooling plate  80  in a manner facing each other and having a slight space (e.g., 1 mm) provided between the heating/reflecting plate  70  and the cooling plate  80 , an air layer, which acts as a thermal insulating material, can be formed between the heating/reflecting plate  70  and the cooling plate  80 . 
         [0052]    In  FIG. 7 , the dual structure body  90 A and dual structure bodies  90 B- 90 D formed in the same manner as the dual structure body  90 A are arranged in a manner surrounding the four sides of the electronic component (rework target)  21  provided on the upper surface of the printed circuit board  20  via the supporting members  91 ,  92  and supporting members  93 ,  94  formed in the same manner as the supporting members  91 ,  92 . 
         [0053]    Accordingly, thermal conductance from the printed circuit board  20  can be restrained (controlled) at an area between the electronic component  21  and the peripheral components  22 ,  23 ,  25 ,  26 , to thermally separate the electronic component  21  and the peripheral components  22 ,  23 ,  25 ,  26  provided on the printed circuit board  20 . 
         [0054]      FIG. 8  is a perspective view for describing a second embodiment of a dual structure body having the heating/reflecting plate  70  of  FIG. 5  and the cooling plate  80  of  FIG. 6  assembled together.  FIG. 8  illustrates a dual structure body  100  having the heating/reflecting plate  70  and the cooling plate  80  supported by and fixed to each other by supporting members  95 ,  96  in a manner where the supporting members  95 ,  96  are interposed between the heating/reflecting plate  70  and the cooling plate  80 . The supporting members  91 ,  92  are formed of a heat insulating material such as ceramic. By positioning the heating/reflecting plate  70  and the cooling plate  80  in a manner facing each other and having a slight space (e.g., 1 mm) provided between the heating/reflecting plate  70  and the cooling plate  80 , an air layer, which acts as a thermal insulating material, can be formed between the heating/reflecting plate  70  and the cooling plate  80 . 
         [0055]    Supporting leg members  101 ,  102  are fixed to the cooling plate  80  at an end part of the cooling plate holding member  82  substantially opposite from the metal cooling plate  81 . The supporting leg members  101 ,  102  together with an end part of the metal heating plate  71  and an end part of the metal cooling plate  81  abut against the printed circuit board  20 , to allow the dual structure body  100  to maintain a predetermined position. 
         [0056]    By preparing various dual structure bodies  100  having different widths W between the heating/reflecting plate  70  and the cooling plate  80 , the dual structure body  100  can be selected in accordance with the length and width of the electronic component  21  (rework target). 
         [0057]    As illustrated in  FIG. 9 , in a case of performing rework soldering, the rated value of the minimum temperature for joining the bumps of the electronic component  21  is no less than 230° C., and the rated value of the heat resistance temperature of the bumps of, for example, the peripheral components  22 ,  23  is no greater than 170° C. 
         [0058]    In a case of performing no temperature control and heating the electronic component  21  and the peripheral components  22 ,  23  simply with the infrared heaters  27 ,  28 , the temperature of the bumps of the electronic component  21  becomes 234° C. and the temperature of the bumps of the peripheral component  22  becomes 235° C. Thus, the temperature of the bumps of the peripheral component  22  surpasses the rated value of 170° C. Further, in a case of using a related art method described with  FIG. 1 , the temperature of the bumps of the electronic component  21  becomes 230° C. and the temperature of the bumps of the peripheral component  22  becomes 205° C. Thus, the temperature of the bumps of the peripheral component  22  surpasses the rated value of 170° C. 
         [0059]    In a case of using the embodiment described with  FIG. 3 , the temperature of the bumps of the electronic component  21  becomes 230° C. and the temperature of the bumps of the peripheral component  22  becomes 167° C. Thus, both the temperatures of the bumps of the electronic component  21  and the bumps of the peripheral component  22  satisfy the rated values. 
         [0060]    According to the above-described embodiments, by using a dual structure body having a heating/reflecting plate and a cooling plate arranged facing each other with a slight space provided therebetween, the heating/reflecting plate and the cooling plate can be mounted in a narrow space(s) between an electronic component and a peripheral component of a printed circuit board. Further, a rework soldering apparatus can be manufactured at a low cost because the dual structure body has a simple configuration. Further, with the dual structure body, lead free soldering of a printed circuit board can be achieved and components can be mounted on a printed circuit board at high density. 
         [0061]    All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiments of the present invention have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.