Patent Publication Number: US-2022226934-A1

Title: Electrode welding method and electrode welding apparatus

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to an electrode welding method and an electrode welding apparatus by which a device in which plural bump electrodes are disposed on a front surface of a semiconductor chip is welded to electrodes of a wiring substrate. 
     Description of the Related Art 
     Devices such as integrated circuits (ICs) and large-scale integration (LSI) circuits in which bump electrodes are disposed on a front surface of a semiconductor chip of silicon or the like are used for pieces of electrical equipment such as portable phones and personal computers through welding of the bump electrodes to electrodes of a wiring substrate. 
     As methods for welding bump electrodes to electrodes of a wiring substrate, there have been proposed techniques in which irradiation with a laser beam is executed from the back surface side of a semiconductor chip and the bump electrodes are melted to be welded to the electrodes of the wiring substrate (for example, refer to Japanese Patent Laid-open No. Hei 02-249247, Japanese Patent Laid-open No. Hei 05-283479, and Japanese Patent Laid-open No. 2006-140295). 
     SUMMARY OF THE INVENTION 
     In the technique described in the above-mentioned Japanese Patent Laid-open No. Hei 02-249247, the whole of the back surface of the semiconductor chip is irradiated with a laser beam to heat and melt the bump electrodes, and the plural bump electrodes are simultaneously welded to connection terminals of a substrate. However, there is a problem that the plural bump electrodes are not uniformly heated and the welding becomes non-uniform. 
     Further, in the techniques described in the above-mentioned Japanese Patent Laid-open No. Hei 05-283479 and Japanese Patent Laid-open No. 2006-140295, irradiation with a laser beam is individually executed with each individual bump electrode targeted. However, a long time is taken, and it is difficult to accurately position the focal point position toward the bump electrode individually. Moreover, there is a problem that it takes a long time to weld all bump electrodes. 
     Thus, an object of the present invention is to provide an electrode welding method and an electrode welding apparatus that can surely weld bump electrodes to electrodes of a wiring substrate. 
     In accordance with an aspect of the present invention, there is provided an electrode welding method by which a device in which a plurality of bump electrodes are disposed on a front surface of a semiconductor chip is welded to electrodes of a wiring substrate. The electrode welding method includes a laser irradiation apparatus preparation step of preparing a laser irradiation apparatus including a laser oscillator that emits a laser beam with a wavelength having absorbability with respect to the semiconductor chip, a spatial light modulator that adjusts energy distribution of the laser beam emitted from the laser oscillator, and a control unit that adjusts the spatial light modulator in order to make a heating temperature of the plurality of bump electrodes uniform by the laser beam with which irradiation is executed, an electrode positioning step of positioning the bump electrodes corresponding to the electrodes of the wiring substrate, and an electrode welding step of irradiating a back surface of the semiconductor chip with the laser beam and welding the bump electrodes of the device to the electrodes of the wiring substrate, after executing the electrode positioning step. 
     In accordance with another aspect of the present invention, there is provided an electrode welding apparatus that welds a device in which a plurality of bump electrodes are disposed on a front surface of a semiconductor chip to electrodes of a wiring substrate. The electrode welding apparatus includes a laser irradiation apparatus including a laser oscillator that emits a laser beam with a wavelength having absorbability with respect to the semiconductor chip, a spatial light modulator that adjusts energy distribution of the laser beam emitted by the laser oscillator, and a control unit that adjusts the spatial light modulator in order to make a heating temperature of the plurality of bump electrodes uniform by the laser beam with which irradiation is executed, a table that supports the wiring substrate and supports the device in which the bump electrodes are positioned corresponding to the electrodes of the wiring substrate, and a processing movement mechanism that causes relative processing movement of the laser irradiation apparatus and the table. 
     Preferably, the laser irradiation apparatus further includes a beam condenser that condenses a laser beam resulting from the adjustment of the energy distribution by the spatial light modulator. 
     According to the electrode welding method of the present invention, by the spatial light modulator, the heated regions in the semiconductor chip that configures the device are selectively adjusted, and the bump electrodes are uniformly heated, so that the bump electrodes of the device can surely be welded to the electrodes of the wiring substrate. Thus, the problem that melting of the plural bump electrodes becomes non-uniform is eliminated. 
     According to the electrode welding apparatus of the present invention, by the spatial light modulator, the heated regions in the semiconductor chip that configures the device are selectively adjusted, and the bump electrodes are uniformly heated, so that the bump electrodes of the device can surely be welded to the electrodes of the wiring substrate. Thus, the problem that melting of the plural bump electrodes becomes non-uniform is eliminated. 
     The above and other objects, features and advantages of the present invention and the manner of realizing them will become more apparent, and the invention itself will best be understood from a study of the following description and appended claims with reference to the attached drawings showing a preferred embodiment of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an overall perspective view of an electrode welding apparatus of an embodiment of the present invention; 
         FIG. 2  is a block diagram illustrating an optical system of a laser irradiation apparatus disposed in the electrode welding apparatus illustrated in  FIG. 1 ; 
         FIG. 3A  is a perspective view illustrating a suction adhesion part of a conveying arm of a device conveying unit disposed in the electrode welding apparatus illustrated in  FIG. 1  in an enlarged manner; 
         FIG. 3B  is a sectional view along line A-A in  FIG. 3A ; 
         FIG. 4A  is a perspective view illustrating the form of causing suction adhesion of a device by the suction adhesion part of the conveying arm in an electrode positioning step of the present embodiment; 
         FIG. 4B  is a sectional view illustrating one part in the execution form illustrated in  FIG. 4A  in an enlarged manner; 
         FIG. 5  is a perspective view illustrating the form of positioning the device directly under a beam condenser in the electrode positioning step; 
         FIG. 6A  is a side view illustrating the execution form of an electrode welding step; and 
         FIG. 6B  is a conceptual diagram illustrating a section of one part in the execution form illustrated in  FIG. 6A  in an enlarged manner. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An electrode welding method of an embodiment of the present invention and an electrode welding apparatus suitable for the electrode welding method will be described in detail below with reference to the accompanying drawings. 
     In  FIG. 1 , an overall perspective view of an electrode welding apparatus  1  of the present embodiment is illustrated. The electrode welding apparatus  1  includes a base  2 , a holding unit  3  including a table  34  that supports a wiring substrate  10  to be described later, a processing movement mechanism  4  that moves the holding unit  3  over the base  2 , a laser irradiation apparatus  5  including a spatial light modulator (SLM)  54  to be described later, an imaging unit  6 , a device conveying unit  7 , a device supply unit  8 , a display unit  9 , a control unit  100  that adjusts the above-described spatial light modulator  54 , and input means  110  with which predetermined information is input to the control unit  100 . 
     The holding unit  3  includes an X-direction movable plate  31  disposed movably along guide rails  2 A disposed in an X-direction indicated by an arrow X in the diagram, a Y-direction movable plate  33  disposed movably along guide rails  32  disposed in a Y-direction orthogonal to the X-direction over the X-direction movable plate  31 , and the table  34  that has a rectangular shape and is set on the upper surface of the Y-direction movable plate  33  rotatably in a direction indicated by an arrow R 1 . Plural suction holes  342  and suction grooves  343  are formed on a holding surface  341  that configures the upper surface of the table  34 , and the suction holes  342  are connected to suction means, of which diagrammatic representation is omitted, through the inside of the table  34 . By actuating the suction means, a suction negative pressure is supplied to the suction holes  342  and the suction grooves  343 , and the wiring substrate  10  illustrated in the diagram can be sucked and supported. The wiring substrate  10  is a substrate on which a device  16  illustrated in the diagram is mounted through electrode welding, and plural electrodes  14  are formed in a device installing region  12  (illustrated by a one-dot chain line) formed in a front surface  10   a . The XY-plane defined by the above-described X-direction and Y-direction is substantially horizontal. 
     The processing movement mechanism  4  is means that causes relative processing movement of the laser irradiation apparatus  5  and the above-described table  34  and, more specifically, includes an X-direction movement mechanism  41  and a Y-direction movement mechanism  42 . The X-direction movement mechanism  41  has a ball screw  41   b  that extends in the X-direction over the base  2  and a motor  41   a  coupled to a single end part of the ball screw  41   b . A nut part (not illustrated) of the ball screw  41   b  is fixed to the lower surface of the X-direction movable plate  31 . Further, the X-direction movement mechanism  41  converts rotational motion of the motor  41   a  to linear motion by the ball screw  41   b  and transmits the linear motion to the X-direction movable plate  31  through the nut part to cause the X-direction movable plate  31  to advance and retreat in the X-direction along the guide rails  2 A on the base  2 . The Y-direction movement mechanism  42  has a ball screw  42   b  that extends in the Y-direction over the X-direction movable plate  31  and a motor  42   a  coupled to a single end part of the ball screw  42   b . A nut part (not illustrated) of the ball screw  42   b  is formed on the lower surface side of the Y-direction movable plate  33 . Further, the Y-direction movement mechanism  42  converts rotational motion of the motor  42   a  to linear motion by the ball screw  42   b  and transmits the linear motion to the Y-direction movable plate  33  through the nut part to cause the Y-direction movable plate  33  to advance and retreat in the Y-direction along the guide rails  32  on the X-direction movable plate  31 . A rotational drive mechanism (not illustrated) is further included in the processing movement mechanism  4 . The rotational drive mechanism has a motor incorporated in the table  34  and rotates the table  34  in the direction indicated by the arrow R 1  relative to the Y-direction movable plate  33 . 
     On the back side of the holding unit  3  on the base  2 , a frame body  21  including a perpendicular wall part  21   a  that extends upward from the upper surface of the base  2  and a horizontal wall part  21   b  that horizontally extends from the upper end of the perpendicular wall part  21   a  is disposed upright. An optical system of the laser irradiation apparatus  5  including the spatial light modulator  54  in the present embodiment is incorporated in the horizontal wall part  21   b . As is understood from a block diagram that illustrates the outline of the laser irradiation apparatus  5  in  FIG. 2 , the laser irradiation apparatus  5  includes a laser oscillator  51  that emits a laser beam LB, an attenuator  52  that adjusts the output power of the laser beam LB emitted from the laser oscillator  51 , a reflective mirror  53  that changes the optical path of the laser beam LB applied from the attenuator  52  as appropriate, and the spatial light modulator  54  that adjusts the energy distribution of the laser beam LB guided from the reflective mirror  53 . The laser irradiation apparatus  5  further includes a beam condenser  55  including a condensing lens (not illustrated) that condenses a laser beam LB 0  resulting from the adjustment of the energy distribution by the spatial light modulator  54 , the control unit  100  that outputs an instruction signal of the adjustment of the energy distribution by the spatial light modulator  54 , and the input means  110  with which information on the device  16  to be described later is input to the control unit  100 . 
     As illustrated in  FIG. 1 , the beam condenser  55  is disposed on the lower surface of the tip part of the horizontal wall part  21   b  of the frame body  21 . In the present embodiment, an example in which a reflective type (liquid crystal on silicon (LCOS)) is employed as the spatial light modulator  54  is described. However, the present invention is not limited thereto, and a spatial light modulator of a transmissive type (liquid crystal (LC)) may be employed with change in the optical path of the laser beam LB emitted from the laser oscillator  51 . The beam condenser  55  is what is disposed in order to adjust the beam dimensions of the laser beam LB 0  resulting from the adjustment of the energy distribution by the spatial light modulator  54  and can be omitted depending on the size of the workpiece. Further, the attenuator  52  and the reflective mirror  53  are also what are disposed as appropriate according to need and can be omitted as appropriate. 
     In the horizontal wall part  21   b , a Z-direction movement mechanism (not illustrated) that moves the beam condenser  55  in a Z-direction (upward-downward direction) indicated by an arrow Z is disposed. The Z-direction movement mechanism configures a movement mechanism that causes the laser irradiation apparatus  5  and the table  34  to relatively advance and retreat in the Z-direction in the processing movement mechanism  4 . 
     The imaging unit  6  is disposed on the lower surface of the tip of the horizontal wall part  21   b  and at a position at an interval from the beam condenser  55  of the laser irradiation apparatus  5  in the X-direction. In the imaging unit  6 , for example, an optical system including illuminating means that executes irradiation with light including a visible beam and an imaging element (charge coupled device (CCD)) that executes imaging of an image obtained due to reflection of visible light is included. The display unit  9  that displays an image obtained by the imaging by the imaging unit  6  is mounted on the upper surface of the horizontal wall part  21   b  of the frame body  21 . 
     The device conveying unit  7  includes a casing  71  that has a rectangular parallelepiped shape and that extends upward from the termination part of the guide rails  2 A disposed along the X-direction on the base  2 , a support arm  72  that extends in the X-direction and that is supported in such a manner as to be capable of rising and lowering by raising-lowering means that is housed in the casing  71  and of which diagrammatic representation is omitted, and a motor  73  disposed at the tip of the support arm  72 . The device conveying unit  7  further includes a circular plate  74  rotated by the motor  73 , a conveying arm  75  disposed on the circular plate  74 , and a suction adhesion part  76  disposed at the tip of the conveying arm  75 . The suction adhesion part  76  will be described in more detail with reference to  FIGS. 3A and 3B . 
     At the upper stage of  FIG. 3A , a perspective view when the suction adhesion part  76  disposed at the tip of the conveying arm  75  is viewed from an obliquely upper side is illustrated. At the lower stage, a perspective view when the suction adhesion part  76  is viewed from an obliquely lower side is illustrated. As illustrated in the diagram, the suction adhesion part  76  includes a frame part  761  having a substantially rectangular shape in plan view and a rectangular through-hole  762  that is surrounded by the frame part  761  and vertically penetrates. As is understood from the diagram of the lower stage of  FIG. 3A  and  FIG. 3B  that illustrates a section along line A-A in the diagram of the upper stage of  FIG. 3A , a step part  763  is formed on the lower surface side of the frame part  761  of the suction adhesion part  76 , and plural suction holes  764  are disposed in the step part  763  at equal intervals. The suction holes  764  are connected to suction means, of which diagrammatic representation is omitted, through the conveying arm  75 , the support arm  72 , and so forth. By actuating the suction means, suction adhesion of the device  16  with dimensions that substantially correspond with the shape of the step part  763  in plan view can be caused. 
     Referring back to  FIG. 1 , the device supply unit  8  includes a support pedestal  81  formed into a box shape, a support base  82  disposed on the upper surface of the support pedestal  81 , guide rails  82 A disposed along the X-direction on the support base  82 , and an X-direction moving plate  84  disposed movably in the X-direction along the guide rails  82 A. The device supply unit  8  further includes guide rails  84 A disposed along the Y-direction on the X-direction moving plate  84 , a pallet  86  disposed movably in the Y-direction along the guide rails  84 A, an X-direction movement mechanism  83  that moves the X-direction moving plate  84  along the X-direction, and a Y-direction movement mechanism  85  that moves the pallet  86  along the Y-direction. 
     The X-direction movement mechanism  83  of the above-described device supply unit  8  includes a motor  83   a  and a ball screw  83   b  rotated by the motor  83   a , and the Y-direction movement mechanism  85  includes a motor  85   a  and a ball screw  85   b  rotated by the motor  85   a . A configuration by which the X-direction moving plate  84  is caused to advance and retreat in the X-direction by the X-direction movement mechanism  83  and a configuration by which the pallet  86  is caused to advance and retreat in the Y-direction by the Y-direction movement mechanism  85  are substantially the same as that of the above-described processing movement mechanism  4  and therefore, detailed description thereof is omitted. 
     The pallet  86  is formed into a flat plate shape and houses the devices  16  in a surface in which plural regions are marked out in a lattice manner. As illustrated in a sectional view of  FIG. 4B , the device  16  is an object in which plural bump electrodes  18  are disposed on a front surface  17   a  of a semiconductor chip  17 . The pallet  86  in the embodiment illustrated in  FIG. 1  houses 4×4=16 devices  16 . The devices  16  are housed in the pallet  86  in such a manner that the front surface  17   a  on which the plural bump electrodes  18  are formed is oriented downward and a back surface  17   b  is oriented upward. 
     Although a wiring diagram is omitted, the above-described control unit  100  is also connected to, in addition to the spatial light modulator  54  of the laser irradiation apparatus  5 , the X-direction movement mechanism  41 , the Y-direction movement mechanism  42 , and the rotational drive mechanism, of which diagrammatic representation is omitted, in the processing movement mechanism  4 , the device conveying unit  7 , and the X-direction movement mechanism  83  and the Y-direction movement mechanism  85  of the device supply unit  8 . Further, position detecting means of which diagrammatic representation is omitted is disposed for each of the X-direction movement mechanism  41 , the Y-direction movement mechanism  42 , and the rotational drive mechanism, of which diagrammatic representation is omitted, in the processing movement mechanism  4 , the device conveying unit  7 , and the X-direction movement mechanism  83  and the Y-direction movement mechanism  85  of the device supply unit  8 , and the configuration is made in such a manner that the table  34  and the pallet  86  can be accurately moved to a desired coordinate position in the XY-plane. 
     The electrode welding apparatus  1  of the present embodiment has the configuration that is substantially as described above. A description will be made below about an electrode welding method that is executed with use of the electrode welding apparatus  1  and by which the device  16  in which the plural bump electrodes  18  are disposed on the front surface  17   a  of the semiconductor chip  17  is welded to the electrodes  14  of the wiring substrate  10 . 
     The device  16  welded to the wiring substrate  10  by the electrode welding method of the present embodiment is an object including the semiconductor chip  17  and the plural bump electrodes  18  disposed on the front surface  17   a  of the semiconductor chip  17  as described above, and the semiconductor chip  17  is formed of a silicon (Si) chip, for example. Further, in the front surface  10   a  of the wiring substrate  10 , the device installing region  12  in which the electrodes  14  are formed corresponding to the plural bump electrodes  18  of the device  16  is formed. 
     In the execution of the electrode welding method of the present embodiment, the laser irradiation apparatus  5  described based on  FIG. 2  is prepared. Specifically, the laser oscillator  51  disposed in the laser irradiation apparatus  5  is what oscillates the laser beam LB with a wavelength having absorbability with respect to this silicon chip, and the laser irradiation apparatus  5  configured to include the spatial light modulator  54  that adjusts the energy distribution of the laser beam LB oscillated by the laser oscillator  51  and the control unit  100  that adjusts the spatial light modulator  54  in order to make the temperature of the plural bump electrodes  18  uniform by the laser beam LB with which irradiation is executed is prepared (laser irradiation apparatus preparation step). 
     After the above-described laser irradiation apparatus preparation step is executed, an electrode positioning step of positioning the bump electrodes  18  of the device  16  corresponding to the electrodes  14  of the wiring substrate  10  is executed. The electrode positioning step is executed through the following procedure, schematically. 
     First, as illustrated in  FIG. 1 , the table  34  is positioned to a carrying-out/in position with which the wiring substrate  10  is carried out and in. 
     Subsequently, the wiring substrate  10  is placed on the table  34  in such a manner that the front surface  10   a  of the wiring substrate  10  is oriented upward and a back surface  10   b  is oriented downward, and the suction means of which diagrammatic representation is omitted is actuated to supply a suction negative pressure to the suction holes  342  and the suction grooves  343  and support the wiring substrate  10 . Next, the processing movement mechanism  4  is actuated to move the table  34 , and the wiring substrate  10  is positioned directly under the imaging unit  6 . The device installing region  12  and the electrodes  14  on the wiring substrate  10  are imaged and the position thereof is detected, and information on the position is stored in a storing section (memory) of the control unit  100  (alignment). The electrodes  14  on the wiring substrate  10  correspond to the plural bump electrodes  18  formed in the device  16 . 
     Before, after, or simultaneously with the above-described alignment, the X-direction movement mechanism  83  and the Y-direction movement mechanism  85  of the device supply unit  8  are actuated, and the pallet  86  is positioned to a predetermined position. The predetermined position is a position with which the device  16  that is housed in the pallet  86  and is desired to be subjected to suction adhesion is positioned at a predetermined suction adhesion position when, as illustrated in  FIG. 4A , the device conveying unit  7  is actuated to rotate the conveying arm  75  in a direction of an arrow R 3  and the suction adhesion part  76  is positioned to the suction adhesion position. After the pallet  86  is positioned to the predetermined position as above, as illustrated in  FIG. 4A , the device conveying unit  7  is actuated to rotate the conveying arm  75  in the direction indicated by the arrow R 3 , and the suction adhesion part  76  is positioned to the suction adhesion position. The device  16  to be conveyed next has been positioned directly under the suction adhesion part  76  positioned to the suction adhesion position. 
     Subsequently, as illustrated in  FIG. 4B , the raising-lowering means, of which diagrammatic representation is omitted, in the device conveying unit  7  is actuated to lower the suction adhesion part  76  in a direction indicated by an arrow R 4 . As illustrated in the diagram, the device  16  in which the plural bump electrodes  18  are formed on the front surface  17   a  of the semiconductor chip  17  is housed in the pallet  86  with the back surface  17   b  oriented upward, and the back surface  17   b  of the semiconductor chip  17  is housed in the step part  763  of the suction adhesion part  76 . Next, the above-described suction means is actuated and a suction negative pressure V is supplied to the suction holes  764 . Suction adhesion of the back surface  17   b  of the semiconductor chip  17  to the suction adhesion part  76  is thereby caused. As a result, suction adhesion of the device  16  by the suction adhesion part  76  is caused. Subsequently, the conveying arm  75  is raised and, as illustrated in  FIG. 5 , the conveying arm  75  is rotated in a direction indicated by an arrow R 5  and the suction adhesion part  76  is positioned directly under the beam condenser  55 . 
     In addition to the positioning of the suction adhesion part  76  directly under the beam condenser  55 , the processing movement mechanism  4  is actuated to move the table  34  in a direction indicated by an arrow R 6  in  FIG. 5 . More specifically, based on the position information of the device installing region  12  and the electrodes  14  of the wiring substrate  10  detected by the alignment, the electrodes  14  of the device installing region  12  of the wiring substrate  10  are positioned directly under the beam condenser  55  of the laser irradiation apparatus  5 . As a result, in plan view, the device  16  and the device installing region  12  of the wiring substrate  10  are positioned directly under the beam condenser  55 . In addition, the plural bump electrodes  18  formed on the front surface  17   a  of the semiconductor chip  17  of the device  16  are positioned corresponding to the electrodes  14  formed in the device installing region  12 . Then, the conveying arm  75  of the device conveying unit  7  is lowered, and the bump electrodes  18  of the device  16  are brought into contact with the electrodes  14  formed in the device installing region  12  of the wiring substrate  10 . Through the above, the electrode positioning step is completed. 
     After the above-described electrode positioning step is executed, an electrode welding step of irradiating the back surface  17   b  of the semiconductor chip  17  with a laser beam and welding the bump electrodes  18  of the device  16  to the electrodes  14  of the wiring substrate  10  is executed. More specifically, first, device information is input to the control unit  100  through the input means  110  in advance. The input means  110  with which the device information is input is not necessarily an essential configuration, and the device information may be what is obtained through a communication network or the like. In the device information, information relating to dimensions of the device  16 , information on the disposing position of the bump electrodes  18  formed on the front surface  17   a  of the semiconductor chip  17 , and information relating to the material, thickness, and so forth of the semiconductor chip  17  are included. Based on these pieces of information, as illustrated in  FIG. 6A , the above-described Z-direction movement mechanism of the processing movement mechanism  4  is actuated to adjust the position of the beam condenser  55  in the Z-direction, and the laser irradiation apparatus  5  is actuated and the instruction signal is sent from the control unit  100  to the spatial light modulator  54 . In addition, the laser beam LB is emitted from the above-described laser oscillator  51  and is guided to the spatial light modulator  54 , and the laser beam LB 0  resulting from adjustment of the energy distribution of the laser beam LB is output from the spatial light modulator  54 , so that the back surface  17   b  of the semiconductor chip  17  is irradiated with the laser beam LB 0  as illustrated in  FIG. 6B . 
     A continuous wave (CW) is employed as the laser beam LB emitted by the laser irradiation apparatus  5  of the present embodiment and is set to the following processing condition, for example. 
     Wavelength: 400 to 1100 nm 
     Average Output Power: 80 to 300 W/cm 2    
     As for the wavelength of the laser beam LB, it is preferable to set the wavelength to 900 to 1000 nm, with which reflection is suppressed at the front surface  17   a  of the semiconductor chip  17  and absorption into Si can be ensured, because the semiconductor chip  17  of the present embodiment is configured by Si. 
     According to the above-described embodiment, as is understood by  FIG. 6B  illustrated as a conceptual diagram, the laser beam LB 0  with which the irradiation is executed from the back surface  17   b  of the semiconductor chip  17  selectively adjusts the heated regions in the semiconductor chip  17  as illustrated by LB 1  to LB 7  and makes the temperature of the bump electrodes  18  an uniform melting temperature to electrically connect the bump electrodes  18  and the electrodes  14  to each other, the electrodes  14  being formed in the device installing region  12  of the wiring substrate  10 . The device  16  is thereby welded to the wiring substrate  10 , and the table  34  becomes the state of supporting the device  16  in which the bump electrodes  18  are positioned corresponding to the electrodes  14  of the wiring substrate  10  as well as the wiring substrate  10 . Through the above, the electrode welding step is completed. 
     After the above-described electrode welding step is completed, the suction negative pressure supplied to the suction adhesion part  76  is stopped, and the above-described raising-lowering means of the device conveying unit  7  is actuated to raise the suction adhesion part  76  together with the conveying arm  75 . In addition, the processing movement mechanism  4  is actuated, and the table  34  is positioned to the carrying-out/in position at which the table  34  is positioned in  FIG. 1 . Subsequently, the suction means connected to the table  34  is stopped, and the wiring substrate  10  integrated with the device  16  is carried out. Next, the unprocessed wiring substrate  10  to which the device  16  has not been welded is placed on the table  34  and is sucked and supported. After the wiring substrate  10  is supported on the table  34 , the above-described electrode positioning step and electrode welding step are executed. By repeating this, the remaining devices  16  housed in the pallet  86  can be welded to the wiring substrate  10 . 
     According to the above-described embodiment, by the spatial light modulator  54 , the heated regions in the semiconductor chip that configures the device  16  are selectively adjusted and the bump electrodes  18  are uniformly heated, so that the bump electrodes  18  of the device  16  can be favorably welded to the electrodes  14  of the wiring substrate  10 . Due to this, the problem that melting of the plural bump electrodes  18  becomes non-uniform is eliminated. 
     The present invention is not limited to the details of the above described preferred embodiment. The scope of the invention is defined by the appended claims and all changes and modifications as fall within the equivalence of the scope of the claims are therefore to be embraced by the invention.