Abstract:
A method and a apparatus for removing a micro component surely and leveling solder remaining on a substrate without imposing thermal damage to solder lands, the substrate and components on the periphery. A thermosetting adhesive ( 15 ) is provided on the surface ( 12   a ) of a micro component ( 12 ) opposite to the side of a substrate ( 11 ), and the distal end of a component holding pin ( 13 ) having cross-section area falling within the surface ( 12   a ) of the micro component ( 12 ) opposite to the side of the surface ( 11 ) is passed through the thermosetting adhesive ( 15 ) to abut against the surface ( 12   a ) of the micro component ( 12 ). Subsequently, solder ( 16 ) between the micro component ( 12 ) and the substrate ( 11 ) is heated to melt and the component holding pin ( 13 ) is moved in the direction receding from the substrate ( 11 ). Consequently, the micro component ( 12 ) is removed from the substrate ( 11 ).

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This is a continuation of Application PCT/JP2005/012071, filed on Jun. 30, 2005, now pending, the contents of which are herein wholly incorporated by reference. 

   BACKGROUND OD THE INVENTION 
   1. Technical Field 
   A method of and a device for removing a micro component such as a chip component that is equal to or smaller than approximately 1 mm on one side are illustrated. 
   2. Background Art 
   A conventional method of removing a component based on reworking an angular chip component mounted on a substrate is that an operator melts a solder between the angular chip component and the substrate by use of a tapered soldering iron, a tweezers-like soldering iron and thereafter removes the angular chip component while picking up the component. 
   According to the conventional method of manually removing the angular chip component, the manual operation can not be conducted so precisely. It was therefore difficult to remove, for example, the micro component such as an angular chip that is equal to or smaller than 1 mm on one side. 
   Moreover, the heating of the micro component with the soldering iron entails keeping the soldering iron separate from other components. For attaining this, a tip of the solder iron needs tapering on the order of 1 mm or smaller in diameter. When the tip of the soldering iron is tapered, however, a thermal capacity decreases. 
   On the other hand, lead-free soldering has been recently accelerated, and a solder melting temperature rises. Thus, the solder exhibiting the high melting temperature due to the lead-free tendency, as described above, it is difficult to sufficiently melt the solder by employing the soldering iron of which the tip is equal to or smaller than 1 mm in diameter and of which the thermal capacity is small. 
   Such a problem of a decline of the operability therefore arises. Moreover, it happens that the component is raised before the solder gets melted sufficiently. In this case, problems are caused, wherein a solder land is damaged, and a thermal stress is applied to the substrate due to an excess over a predetermined period of heating time. 
   Such being the case, a dedicated rework apparatus is proposed in order to solve these problems. In the rework apparatus, an upper face of the should-be-removed component is sucked by a vacuum nozzle. In this state, the solder between the component and the substrate is heated with warm air and thus melted. Thereafter, the vacuum nozzle is moved upward. The component is thereby removed from the substrate. 
   The conventional rework apparatus, however, employs the vacuum nozzle, and hence, if the component is mounted with a skew on the substrate, a problem is that the component can not be adsorbed by the vacuum nozzle. In this case, the micro component can not be removed. 
   A solution for this type of problem is, it is considered, to expand a diameter of an absorbing port of the vacuum nozzle or to increase the sucking force. If the diameter of the absorbing port and the sucking force are increased, however, such a problem arises that the component itself is sucked into the vacuum nozzle. Further, another problem is caused, wherein the vacuum nozzle sucks the solder and gets clogged. 
   Moreover, in the conventional dedicated rework apparatus, after the component has been removed from the substrate, the solder remaining on the substrate is leveled, and the solder therefore needs reheating after being hardened. In this case, there might be a possibility of exerting thermal damages on the solder land, the substrate and the peripheral components. 
   SUMMARY OF THE INVENTION 
   It is an object, which was devised in view of these problems, to provide a micro component removing method and a micro component removing device capable of surely removing a micro component and leveling solder remaining on a substrate without exerting any thermal damages on a solder land, the substrate and peripheral components. 
   Here is illustrated to solve the problems. 
   A method of removing a micro component soldered to a substrate from the substrate. The method comprising: 
   applying a thermosetting adhesive over a surface, on the opposite side to the substrate, of the micro component; 
   abutting a tip of a component holding pin against the surface of the micro component via the thermosetting adhesive; 
   fixing the component holding pin to the micro component in a way that hardens the thermosetting adhesive by heating the thermosetting adhesive; 
   melting solder by heating the solder between the micro component and the substrate; and 
   removing the micro component from the substrate by moving the component holding pin in such a direction as to get distanced from the substrate. 
   Accordingly, the component holding pin is fixed to the micro component by the thermosetting adhesive, and, after melting the solder between the micro component and the substrate, the micro component is removed from the substrate by moving the component holding pin in such a direction as to get distanced from the substrate. 
   Accordingly, even if the micro component is mounted with a skew on the substrate, the micro component can be surely fixed to the component holding pin. This enables the micro component to be steadily removed. 
   The micro component removing method may further include: 
   embedding, after the solder has been melted, a solder leveling pin into the solder; 
   removing part of the solder adhered to the solder leveling pin by moving the solder leveling pin in such a direction as to get distanced from the substrate in a melted state of the solder; and 
   continuously heating, after adhering part of the solder to the solder leveling pin and removing the solder, the solder remaining on the substrate. 
   In this case, simultaneously with removal of the micro component, the solder can be leveled by continuously heating the solder remaining on the substrate. Consequently, after the solder remaining on the substrate has been cooled and thus hardened, there is no necessity for re-heating this residual solder for leveling, and it is therefore feasible to prevent thermal damages from being exerted on a solder land, components disposed along the periphery of the removed micro component and the substrate. 
   Still further, a micro component removing apparatus for removing a micro component soldered to a substrate is illustrated. The apparatus comprising: 
   a component holding pin having a predetermined sectional area; 
   a pin up-down driving member moving the component holding pin in such directions as to get close to and get distanced from the substrate; and
         a heating member heating a thermosetting adhesive provided on a surface of the micro component and heating the solder between the micro component and the substrate.       

   It is preferable that the heating member includes a soft beam generating portion. In this case, the thermal damages can be prevented from being exerted on the components peripheral to the should-be-removed micro component and on the substrate. White light beams can be exemplified as the soft beams. 
   It is desirable that the pin up-down driving member includes solder leveling pins disposed on both sides of the component holding pin, capable of abutting on lumps of solder exposed on both sides of the micro component, and elastically biased toward the substrate. 
   In this case, the solder leveling pins descend integrally with the component holding pin and abut on the lumps of solder before the lumps of solder are melted. In this state, when the solder is melted, the solder leveling pin is embedded into the solder by dint of elastic biasing force toward the substrate. 
   It is desirable that the predetermined sectional area of the component holding pin is encompassed within the surface of the micro component. 
   In this case, even if an interval between the micro components on the substrate is narrow, when the component holding pin descends, the component holding pin can be prevented from being brought into contact with another micro component neighboring to the should-be-removed micro component. 
   As explained above, the component holding pin is fixed to the micro component by the thermosetting adhesive, and the micro component is removed by raising the component holding pin. 
   Accordingly, even if the micro component is mounted with the skew on the substrate, the component holding pin can be surely fixed to the micro component, and hence the micro component can be steadily removed. 
   Moreover, the solder leveling pins are provided on both sides of the component holding pin, after removing the micro component, in the case of continuously heating the solder, the solder remaining on the substrate can be leveled immediately after the micro component has been removed. 
   Accordingly, after the solder has been cooled and thus hardened, there is no necessity for re-heating in order to level the solder, and it is therefore possible to prevent the thermal damages from being exerted on the solder land, the components peripheral to the should-be-removed micro component and the substrate. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a view illustrating a micro component removing apparatus according to the present invention. 
       FIG. 2  is a view taken along an arrow A in  FIG. 1 , showing a component holding pin and solder leveling pins according to the present invention. 
       FIG. 3  is a sectional view taken along the line B-B in  FIG. 2 , showing a relation between the component holding pin and the micro component according to the present invention, and a relation between the solder leveling pin and solder. 
       FIG. 4  is a flowchart showing a micro component removing method according to the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Such an object is realized that micro components can be surely removed from a substrate, solder remaining on the substrate is leveled without exerting any thermal damages to a solder land, peripheral components to the should-be-removed micro components and the substrate. 
   Detailed descriptions of a micro component removing method and a micro component removing device will hereinafter be made with reference to the drawings. 
     FIG. 1  illustrates a micro component removing apparatus  1 . The micro component removing apparatus  1  is an apparatus that removes a micro component  12  soldered onto a substrate  11  from the substrate  11 . 
   The micro component removing apparatus  1  includes a component holding pin  13  having a predetermined sectional area, a pin up-down driving member  14  that moves the component holding pin  13  in such directions as to get close to and get distanced from the substrate  11 , a thermosetting adhesive  15  provided on a surface  12   a  of the micro component  12 , and a heating member  17  that heats a solder  16  between the micro component  12  and the substrate  11  at a predetermined temperature. 
   In the first embodiment, the sectional area of the component holding pin  13  is a size encompassed within the surface  12   a , on the opposite side to the substrate  11 , of the micro component  12 . 
   Further, the micro component removing apparatus  1  has solder leveling pins  18  provided at the pin up-down driving member  14 . The solder leveling pins  18  are, as illustrated in  FIG. 2 , disposed on both sides of the component holding pin  13  and can abut on the solders  16  exposed on both sides of the micro component  12 . Further, the solder leveling pins  18  are elastically biased toward the substrate  11  by elastic biasing members  28  that will be described later on. 
   Note that a numeral  20  in  FIG. 1  stands for an X-Y stage that moves the substrate  11  in X-Y directions within a horizontal plane, and the numeral  21  represents a solder land (conductor pattern) provided on the substrate  11 . 
   Next, the respective components will be explained. Note that the components other than those described below can involve using general types of components, and hence their detailed explanations are omitted. 
   The micro component  12  can be exemplified by an angular chip that is equal to or smaller than 1 mm on one side and is equal to or smaller than 0.5 mm on the other side. Thus, it is difficult for an operator to manually remove the extremely small micro component  12  from the substrate  11  by use of a soldering iron. 
   The component holding pin  13  is formed in a bar shape. Further, as shown in  FIG. 3 , the component holding pin  13  is formed in a circular shape in section. A sectional area of the component holding pin  13  has a size encompassed within the surface  12   a  of the micro component  12 . 
   In the first embodiment, the solder leveling pin  18  takes a bar shape similarly to that of the component holding pin  13 . Further, the section of the solder leveling pin  18  is formed in a circular shape. Still further, a sectional area of the solder leveling pin  18  has a size encompassed within the surface  12   a  of the micro component  12 . 
   The pin up-down driving member  14  includes, as illustrated in  FIG. 1 , a horizontal arm  25  having a proper length and a moving portion  26  that moves the horizontal arm  25  up and down. 
   The horizontal arm  25  is, as illustrated in  FIG. 2 , an elongate member taking a square shape in section. A leading end of the horizontal arm  25  is fitted with the component holding pin  13  in a way that makes up-down directional positions adjustable. 
   Moreover, the leading end of the horizontal arm  25  is provided with sub-arms  27 ,  27  extending on both sides. The solder leveling pins  18 ,  18  are provided at leading ends of these sub-arms  27 ,  27  via the elastic biasing members  28 . 
   The elastic biasing member  28  includes a bottomed cylindrical member  40  and a compression coil spring  29  provided within the cylindrical member  40 . An upper end of the solder leveling pin  18  is inserted into the cylindrical member  40 . Then, the solder leveling pin  18  is biased by the compression coil spring  29  toward the substrate  11 . 
   Moreover, an interval between the cylindrical member  40 ,  40  in the elastic biasing members  28 ,  28  on both sides is slightly larger than an external interval L between terminal portions  12   b ,  12   b  of the micro component  12 . With this contrivance, the solder leveling pins  18 ,  18  provided at the elastic biasing members  28 ,  28  can abut on the lumps of solder  16 ,  16  exposed sideways of the micro component  12 . 
   Note that before the solder leveling pins  18 ,  18  abut on the lumps of solder  16 ,  16 , a post flux  30  is applied over the leading ends of the solder leveling pins  18 ,  18 . The post flux  30  has a property harmonizing with the solder  16 . 
   As shown in  FIG. 1 , the moving portion  26  of the pin up-down driving member  14  has a screw member  32  and a nut member  33  screwed to the screw member  32 . The horizontal arm  25  is secured to the nut member  33 . Further, a motor  34  capable of making forward and reverse rotations is connected to the screw member  32 . 
   When the motor  34  rotates, the screw member  32  is rotated. With this operation, the nut member  33  slidably moves on the screw member  32 , while the horizontal arm  25 , the component holding pin  13  and the solder leveling pins  18 ,  18  move upward or downward. 
   The heating member  17  includes, as illustrated in  FIG. 1 , a soft beam generating portion  35 , a diaphragm lens  36 , a mask member  37  and a cover member  38 . 
   The soft beam generating portion  35  emits white light beams. The soft beam generating portion  35  can be exemplified by, e.g., a halogen lamp. The diaphragm lens  36  can be exemplified by a convex lens. The diaphragm lens  36  converges the beams generated by the soft beam generating portion  35 . The soft beams are easier in terms of controlling a heating temperature and a period of heating time than by laser beams. 
   The mask member  37  includes a hole  37   a  having a predetermined size. The soft beams converged by the diaphragm lens  36  irradiate only a predetermined range via a hole  37   a . The hole  37   a  has a size equivalent to a range embracing the should-be-removed micro component  12  and the solders  16  exposed sideways of the micro component  12 . Further, the hole  37   a  is formed in such a shape and a size that the components, other than the predetermined range, peripheral to the should-be-removed micro component  12  are not irradiated with the soft beams. 
   The heating member  17  can adjust a focal length of the soft beams by adjusting a distance between the soft beam generating portion  35  and the diaphragm lens  36  and a distance between the diaphragm lens  36  and the mask member  37 . 
   Next, a method, by which the micro component removing apparatus  1  removes the micro component  12  mounted on the substrate  11 , will be described with reference to  FIG. 4 . 
   To begin with, a preparatory step is that before the should-be-removed micro component  12  is disposed immediately under the component holding pin  13 , a proper quantity of thermosetting adhesive  15  is applied over the upper face (surface)  12   a  of the micro component  12  (S 1 ). Here at, the thermosetting adhesive  15  still remains softened. 
   Next, the post flux  30  is applied to lower end faces of the solder leveling pins  18 ,  18  (S 2 ). At this time, the component holding pin  13  and the solder leveling pins  18 ,  18  are disposed in ascending limit positions. 
   Next, an X-Y directional position of the substrate  11  is adjusted by the X-Y stage  20 . With this adjustment, the micro component  12  is disposed just under the component holding pin  13 . The lumps of solder  16 ,  16  extruding sideways from the terminal portions  12   b ,  12   b  of the micro component  12  are disposed directly under the solder leveling pins  18 ,  18  (S 3 ). 
   Next, the horizontal arm  25  of the pin up-down driving member  14  is descended. Then, the component holding pin  13  fitted to the horizontal arm  25  and the solder leveling pins  18 ,  18  abut on the surface  12   a  of the micro component  12  and on the lumps of solder  16 ,  16 , respectively (S 4 ). 
   Subsequently, the soft beam generating portion  35  of the heating member  17  emits the soft beams. The soft beams travel through the diaphragm lens  36  and the hole  37   a  of the mask member  37 , and irradiate the predetermined range embracing the target micro component  12 , the thermosetting adhesive  15  and the lumps of solder  16 ,  16  exposed sideways from the target micro component  12  (S 5 ). 
   When the thermosetting adhesive  15  is irradiated with the soft beams for a predetermined period of time, the thermosetting adhesive  15  gets hardened. The component holding pin  13  is thereby fixed to the micro component  12  (S 6 ). 
   Further, the solder  16  is irradiated with the soft beams for a predetermined period of time and is thereby melted. Then, the solder leveling pin  18  elastically biased toward the solder  16  by the compression coil spring  29  moves toward the substrate  11  and is embedded into the melted solder  16  (S 7 ). 
   At this time, the melted solder  16  is harmonized with the post flux  30  applied to the solder leveling pin  18  and is thus adhered to the solder leveling pin  18 . 
   Next, the horizontal arm  25  of the pin up-down driving member  14  ascends, and the solder leveling pins  18 ,  18  are moved in such a direction as to get distanced from the substrate  11  (S 8 ). 
   With this operation, ascending force acts on the micro component  12  fixed to the component holding pin  13 . At this time, the lumps of solder  16 ,  16  between the micro component  12  and the substrate  11  have already melted, and hence, with the ascendance of the component holding pin  13 , the micro component  12  is removed from the substrate  11 . 
   Further, some of the lumps of solder  16 ,  16  adhered to the solder leveling pin  18  are removed by dint of the ascendance of the solder leveling pin  18 . 
   Thus, simultaneously with the removal of the micro component  12  from the substrate  11 , some of the lumps of solder  16 ,  16  are removed from on a solder land  21 , and thereafter the irradiation of the soft beams continues for a predetermined period of time, e.g., for several seconds (S 9 ). 
   With this operation, the lumps of solder  16 ,  16  remaining on the solder land  21  retain their melted state for the predetermined period of time. Further, a part of the post flux  30  applied to the solder leveling pin  18  is transferred onto the solder  16 . 
   Then, the melted solder  16  is harmonized with the post flux  30 , thereby decreasing a depth of ruggedness formed when removing part of the solder  16 . The solder  16  is thereby leveled in a semicylindrical shape. 
   After the irradiation of the soft beams for the predetermined period of time, the emission of the soft beams is stopped (S 10 ). 
   Thus, in the micro component removing apparatus  1  and the micro component removing method, the component holding pin  13  having the predetermined sectional area is fixed to the micro component  12  by the thermosetting adhesive  15 . 
   Then, after the lumps of solder  16 ,  16  between the micro component  12  and the substrate  11  have been heated and melted by the soft beams, the component holding pin  13  ascends. The micro component  12  is thereby removed from the substrate  11 . 
   Accordingly, even when the micro component  12  is mounted with a skew on the substrate  11 , the component holding pin  13  can be surely fixed to the micro component  12 , and hence the micro component  12  can be certainly removed. 
   Moreover, simultaneously with the removal of the micro component  12 , part of the solder  16  is removed by the solder leveling pin  18 . Thereafter, the solder  16  remaining on the solder land  21  continues to be heated for the predetermined period of time by the soft beams. The solder  16  is thereby leveled. 
   Namely, in continuation with the removal of the micro component  12 , the solder  16  remaining on the substrate  11  is leveled. 
   This operation, for leveling the solder  16  remaining on the solder land  21 , eliminates a necessity for heating again the solder  16  after the solder  16  has been cooled and then hardened. 
   It is therefore feasible to prevent the thermal damages from being exerted on the solder land  21 , the components disposed along the periphery of the removed micro component  12  and the substrate  11 . 
   Further, the predetermined range embracing the thermosetting adhesive  15  and the lumps of solder  16 ,  16  is irradiated spotwise with the soft beams. Accordingly, it is possible to prevent the components peripheral to the should-be-removed micro component  12  from being excessively overheated and to therefore prevent the thermal damages from being exerted on these components. 
   Moreover, the lumps of solder  16 ,  16  between the components peripheral to the should-be-removed micro component  12  and the substrate  11  can be prevented from being melted again, and hence the reliability of the substrate  11  can be prevented from declining. 
   Furthermore, the solder  16  is heated by the soft beams and can be therefore surely melted even when employing the solder exhibiting a high melting temperature as in the case of a lead-free solder. 
   Moreover, the components peripheral to the lumps of solder  16 ,  16  can be prevented from being excessively overheated because of using the soft beams that are easy to control the heating temperature and the heating time in order to heat the lumps of solder  16 ,  16 . The thermal damages can be thereby prevented from being exerted on the components peripheral to the lumps of solder  16 ,  16 . 
   Note that when using the laser beams in place of the soft beams, the heating temperature and the heating time are difficult to be controlled, and there might be a possibility that the components peripheral to the lumps of solder  16 ,  16  are excessively heated. It is therefore not preferable that the laser beams are employed. 
   Moreover, the component holding pin  13  and the solder leveling pin  18  each takes a bar-like shape, and their sectional areas have sizes each encompassed within the surface  12   a , on the opposite side to the substrate  11 , of the micro component  12 . 
   With this contrivance, it is possible to prevent, when the component holding pin  13  and the solder leveling pin  18  descend toward the substrate  11 , the component holding pin  13  and the solder leveling pin  18  from interfering with the components peripheral to the target micro component  12 . 
   Accordingly, the micro component  12  can be removed without being restricted by a component-to-component interval. 
   Note that in the first embodiment, the heating member involves using the soft beam generating portion  35  and can involve employing a heater etc. 
   INDUSTRIAL APPLICABILITY 
   The present invention can be applied to reworking the substrate in the variety of information processing apparatus such as the computer.