Electrode welding method and electrode welding device

Abstract

To provide an electrode welding method and an electrode welding apparatus capable of appropriately welding a bump electrode to an electrode of a wiring board.SOLUTION: An electrode welding method includes: a laser irradiation device preparation step of preparing a laser irradiation device 5 including an oscillator 51 that oscillates a laser beam LB having a wavelength that is absorptive to a semiconductor chip 17, a spatial light modulator 54 that adjusts the energy distribution of the laser beam LB oscillated by the oscillator 51, and control means 100 that adjusts the spatial light modulator 54 so as to equalize the temperature of a plurality of bump electrodes 18 by the irradiated laser beam LB0; an electrode positioning step of positioning the bump electrodes 18 corresponding to electrodes 14 of a wiring substrate 10; and an electrode welding step of irradiating the back surface of the semiconductor chip with the laser beam LB to weld the bump electrodes 18 of a device 16 to the electrodes 14 of the wiring substrate 10, and there is also provided an electrode welding apparatus suitable for the electrode welding method.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to an electrode welding method and an electrode welding apparatus for welding a device having a plurality of bump electrodes disposed on the surface of a semiconductor chip to electrodes of a wiring board. [Background technology]

[0002] Devices such as ICs and LSIs in which bump electrodes are arranged on the surface of semiconductor chips such as silicon, are used in electrical equipment such as mobile phones and personal computers with the bump electrodes welded to electrodes on a wiring board.

[0003] As a method for welding bump electrodes to electrodes of a wiring board, a technique has been proposed in which a laser beam is irradiated from the back surface side of a semiconductor chip to melt the bump electrodes and fuse them to the electrodes of the wiring board (see, for example, Patent Documents 1 to 3). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 02-249247 [Patent Document 2] Japanese Patent Application Publication No. 05-283479 [Patent Document 3] JP 2006-140295 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the technology described in the above-mentioned Patent Document 1, a laser beam is irradiated onto the entire back surface of a semiconductor chip to heat and melt the bump electrodes, and multiple bump electrodes are simultaneously welded to connection terminals of a substrate. However, there is a problem in that the multiple bump electrodes are not heated uniformly, resulting in uneven welding.

[0006] Furthermore, in the techniques described in the above-mentioned Patent Documents 2 and 3, a laser beam is aimed at each bump electrode and irradiated individually, but this takes time, and it is difficult to accurately position the focal point toward each bump electrode individually, and there are also problems in that it takes time to weld all of the bump electrodes.

[0007] The present invention has been made in consideration of the above-mentioned circumstances, and its main technical object is to provide an electrode welding method and an electrode welding apparatus that can reliably weld the bump electrodes to the electrodes of the wiring board. [Means for solving the problem]

[0008] In order to solve the above-mentioned main technical problem, according to the present invention, there is provided an electrode welding method for welding a device having a plurality of bump electrodes disposed on the surface of a semiconductor chip made of silicon to an electrode of a wiring board, the method comprising: an oscillator for emitting a laser beam having a wavelength of 900 to 1000 nm that is absorbent for the semiconductor chip; and a spatial light modulator for adjusting the energy distribution of the laser beam oscillated by the oscillator in correspondence with each of the plurality of bump electrodes. 、 Irradiated Applicable The present invention provides an electrode welding method comprising: a laser irradiation device preparation step of preparing a laser irradiation device including a control means for adjusting the spatial light modulator so as to uniformize the heating temperature of a plurality of bump electrodes by a laser beam; an electrode positioning step of positioning the bump electrodes corresponding to the electrodes of a wiring board; and an electrode welding step of operating the spatial light modulator to irradiate the laser beam from the back surface of the semiconductor chip while adjusting the energy distribution of the laser beam so as to uniformize the energy distribution of the laser beam corresponding to each of the plurality of bump electrodes, thereby welding the bump electrodes of the device to the electrodes of the wiring board.

[0009] Further, according to the present invention, Made of silicon An electrode welding apparatus for welding a device having a plurality of bump electrodes arranged on the surface of a semiconductor chip to an electrode of a wiring board, the device having an absorptivity for the semiconductor chip 900~1000nm An oscillator that oscillates a laser beam of a certain wavelength and the energy distribution of the laser beam oscillated by the oscillator Corresponding to each of the plurality of bump electrodes The present invention provides an electrode welding apparatus comprising: a laser irradiation device including a spatial light modulator that adjusts the heating temperature of a plurality of bump electrodes by an irradiated laser beam, and a control means that adjusts the spatial light modulator so as to uniformize the heating temperature of the plurality of bump electrodes by an irradiated laser beam; a table that supports a wiring board and a device in which bump electrodes are positioned corresponding to the electrodes of the wiring board; and a processing and moving means that processes and moves the laser irradiation device and the table relatively.

[0010] Preferably, the device includes a condenser for condensing the laser beam whose energy distribution has been adjusted by the spatial light modulator. Effect of the Invention

[0011] The electrode welding method of the present invention is an electrode welding method for welding a device having a plurality of bump electrodes arranged on the surface of a semiconductor chip made of silicon to an electrode of a wiring board, and includes an oscillator that oscillates a laser beam having a wavelength of 900 to 1000 nm that is absorbed by the semiconductor chip, and a spatial light modulator that adjusts the energy distribution of the laser beam oscillated by the oscillator in correspondence with each of the plurality of bump electrodes. 、 Irradiated Applicable The method includes a laser irradiation device preparation step of preparing a laser irradiation device including a control means for adjusting the spatial light modulator so as to uniformize the heating temperature of the plurality of bump electrodes by a laser beam; an electrode positioning step of positioning the bump electrodes corresponding to the electrodes of the wiring board; and an electrode welding step of operating the spatial light modulator to irradiate the laser beam from the back surface of the semiconductor chip while adjusting the energy distribution of the laser beam to uniformize it corresponding to each of the plurality of bump electrodes, thereby welding the bump electrodes of the device to the electrodes of the wiring board. Therefore, the heating area of ​​the semiconductor chip that constitutes the device is selectively adjusted by the spatial light modulator, the bump electrodes are uniformly heated, and the bump electrodes of the device can be reliably welded to the electrodes of the wiring board, eliminating the problem of uneven melting of the plurality of bump electrodes.

[0012] In addition, the electrode welding device of the present invention is Made of siliconAn electrode welding apparatus for welding a device having a plurality of bump electrodes arranged on the surface of a semiconductor chip to an electrode of a wiring board, the device having an absorptivity for the semiconductor chip 900~1000nm An oscillator that oscillates a laser beam of a certain wavelength and the energy distribution of the laser beam oscillated by the oscillator Corresponding to each of the plurality of bump electrodes The heating temperature of the semiconductor chip that constitutes the device is selectively adjusted by the spatial light modulator, the bump electrodes are uniformly heated, and the bump electrodes of the device can be reliably welded to the electrodes of the wiring board, thereby eliminating the problem of uneven melting of the multiple bump electrodes. The heating temperature of the semiconductor chip that constitutes the device is selectively adjusted by the spatial light modulator, the bump electrodes are uniformly heated, and the bump electrodes of the device can be reliably welded to the electrodes of the wiring board, thereby eliminating the problem of uneven melting of the multiple bump electrodes. [Brief description of the drawings]

[0013] [Figure 1] 1 is an overall perspective view of an electrode welding device according to an embodiment of the present invention; [Diagram 2] 2 is a block diagram showing an optical system of a laser irradiation device disposed in the electrode welding device shown in FIG. 1. [Diagram 3] 2A is an enlarged perspective view showing an adsorption portion of a transport arm of a device transport means disposed in the electrode welding apparatus shown in FIG. 1, and FIG. 2B is a cross-sectional view taken along the line AA of FIG. [Figure 4] FIG. 1A is a perspective view showing how a device is sucked by a suction portion of a transport arm in an electrode positioning step of the present embodiment, and FIG. 1B is a cross-sectional view showing an enlarged cross section of a portion of the embodiment shown in FIG. [Diagram 5] FIG. 13 is a perspective view showing an aspect in which the device is positioned directly below the light collector in the electrode positioning step. [Figure 6] FIG. 2A is a side view showing an embodiment of an electrode welding step, and FIG. 2B is a schematic diagram showing an enlarged cross section of a portion of the embodiment shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of an electrodeposition welding method and an electrodeposition welding apparatus suitable for the electrodeposition welding method will be described in detail with reference to the accompanying drawings.

[0015] 1 shows an overall perspective view of an electrode welding apparatus 1 of this embodiment. The electrode welding apparatus 1 includes a base 2, a holding means 3 having a table 34 supporting a wiring board 10 (described later), a processing and moving means 4 for moving the holding means 3 on the base 2, a laser irradiation device 5 including a spatial light modulator (SLM) 54 (described later), an imaging means 6, a device transport means 7, a device supplying means 8, a display means 9, a control means 100 for adjusting the spatial light modulator 54, and an input means 110 for inputting predetermined information to the control means 100.

[0016] The holding means 3 includes an X-direction movable plate 31 arranged on the base 2 so as to be movable along guide rails 2A, 2A arranged in the X direction indicated by the arrow X in the figure, a Y-direction movable plate 33 arranged on the X-direction movable plate 31 so as to be movable along guide rails 32, 32 arranged in the Y direction perpendicular to the X direction, and a rectangular table 34 arranged on the upper surface of the Y-direction movable plate 33 so as to be rotatable in the direction indicated by the arrow R1. A holding surface 341 constituting the upper surface of the table 34 has a plurality of suction holes 342 and suction grooves 343 formed thereon, and the suction holes 342 are connected to a suction means (not shown) through the inside of the table 34. By operating the suction means, a suction negative pressure is supplied to the suction holes 342 and suction grooves 343, and the illustrated wiring board 10 can be sucked and supported. The wiring board 10 is a board on which a device 16 shown in the figure is attached by electrode welding, and a device installation area 12 (indicated by a dashed line) is formed on the surface 10a, on which a plurality of electrodes 14 are formed. Note that the XY plane defined by the X and Y directions is substantially horizontal.

[0017] The processing movement means 4 is a means for processing and moving the laser irradiation device 5 and the above-mentioned table 34 relatively, and more specifically, includes an X-direction movement means 41 and a Y-direction movement means 42. The X-direction movement means 41 has a ball screw 41b extending in the X-direction on the base 2, and a motor 41a connected to one end of the ball screw 41b. A nut part (not shown) of the ball screw 41b is fixed to the lower surface of the X-direction movable plate 31. The X-direction movement means 41 converts the rotational motion of the motor 41a into linear motion by the ball screw 41b, transmits it to the X-direction movable plate 31 via the nut part, and moves the X-direction movable plate 31 forward and backward in the X direction along the guide rails 2A, 2A on the base 2. The Y-direction movement means 42 has a ball screw 42b extending in the Y direction on the X-direction movable plate 31, and a motor 42a connected to one end of the ball screw 42b. A nut portion (not shown) of the ball screw 42b is formed on the underside of the Y-direction movable plate 33. The Y-direction moving means 42 converts the rotational motion of the motor 42a into linear motion by the ball screw 42b and transmits it to the Y-direction movable plate 33 via the nut portion, and moves the Y-direction movable plate 33 forward and backward in the Y direction along the guide rails 32, 32 on the X-direction movable plate 31. The processing moving means 4 further includes a rotation driving means (not shown), which has a motor built in the table 34 and rotates the table 34 relative to the Y-direction movable plate 33 in the direction indicated by R1.

[0018] A frame 21 having a vertical wall portion 21a extending upward from the upper surface of the base 2 and a horizontal wall portion 21b extending horizontally from the upper end of the vertical wall portion 21a is erected on the base 2 at the rear side of the holding means 3. The horizontal wall portion 21b houses an optical system of the laser irradiation device 5 including the spatial light modulator 54 in this embodiment. As can be seen from the block diagram of the schematic diagram in Fig. 2, the laser irradiation device 5 includes an oscillator 51 that oscillates a laser beam LB, an attenuator 52 that adjusts the output of the laser beam LB oscillated by the oscillator 51, a reflecting mirror 53 that appropriately changes the optical path of the laser beam LB irradiated from the attenuator 52, a spatial light modulator 54 that adjusts the energy distribution of the laser beam LB guided from the reflecting mirror 53, a condenser 55 including a condensing lens (not shown) that condenses the laser beam LB0 whose energy distribution has been adjusted by the spatial light modulator 54, a control means 100 that outputs an instruction signal that adjusts the energy distribution by the spatial light modulator 54, and an input means 110 that inputs information of a device 16, which will be described later, to the control means 100. The condenser 55 is disposed on the lower surface of the tip of the horizontal wall portion 21b of the frame body 21, as shown in Fig. 1. In the illustrated embodiment, the spatial light modulator 54 is of a reflective type (LCOS) but the present invention is not limited to this, and a transmissive type (LC) spatial light modulator may be adopted by changing the optical path of the laser beam LB oscillated by the oscillator 51. The condenser 55 is provided to adjust the beam size of the laser beam LB0 whose energy distribution has been adjusted by the spatial light modulator 54, and may be omitted depending on the size of the workpiece. The attenuator 52 and the reflecting mirror 53 are also provided as necessary and may be omitted as necessary.

[0019] In addition, a Z-direction moving means (not shown) for moving the collector 55 in the Z direction (up and down direction) indicated by the arrow Z is arranged within the horizontal wall portion 21b, and the Z-direction moving means constitutes a moving means for moving the laser irradiation device 5 and the table 34 relatively forward and backward in the Z direction in the processing moving means 4.

[0020] The imaging means 6 is disposed on the lower surface of the tip of the horizontal wall portion 21b at a position spaced apart in the X direction from the condenser 55 of the laser irradiation device 5. The imaging means 6 includes, for example, an optical system equipped with an illumination means for irradiating light including visible light, and an image sensor (CCD) for capturing an image obtained by reflecting the visible light. The display means 9 for displaying the image captured by the imaging means 6 is mounted on the upper surface of the horizontal wall portion 21b of the frame 21.

[0021] The device transport means 7 includes guide rails 2A arranged along the X direction on the base 2, a rectangular parallelepiped casing 71 extending upward from the end of 2A, a support arm 72 extending in the X direction and supported so as to be movable up and down by a lifting means (not shown) housed in the casing 71, a motor 73 arranged at the tip of the support arm 72, a disk 74 rotated by the motor 73, a transport arm 75 arranged on the disk, and an adsorption unit 76 arranged at the tip of the transport arm 75. The adsorption unit 76 will be described in more detail with reference to FIG.

[0022] The upper part of FIG. 3(a) shows a perspective view of the suction unit 76 disposed at the tip of the transport arm 75, as viewed from diagonally above, and the lower part shows a perspective view of the suction unit 76 as viewed from diagonally below. As shown in the figure, the suction unit 76 has a frame portion 761 having a substantially rectangular shape in a plan view, and a rectangular through-hole 762 that is surrounded by the frame portion 761 and penetrates vertically. As can be understood from the lower part of FIG. 3(a) and FIG. 3(b) showing the AA cross section of the upper part of FIG. 3(a), a step portion 763 is formed on the lower surface side of the frame portion 761 of the suction unit 76, and a plurality of suction holes 764 are disposed at equal intervals in the step portion 763. The suction holes 764 are connected to a suction means (not shown) via the transport arm 75, the support arm 72, etc. By operating the suction means, it is possible to suction the device 16 having dimensions that are substantially the same as the shape of the step portion 763 in a plan view.

[0023] Returning to FIG. 1 to continue the explanation, the device supply means 8 comprises a box-shaped support table 81, a support base 82 arranged on the upper surface of the support table 81, guide rails 82A, 82A arranged on the support base 82 along the X direction, an X-direction moving plate 84 arranged so as to be movable in the X direction along the guide rails 82A, 82A, guide rails 84A, 84A arranged on the X-direction moving plate 84 along the Y direction, a pallet 86 arranged so as to be movable in the Y direction along the guide rails 84A, 84A, an X-direction moving means 83 for moving the X-direction moving plate 84 along the X direction, and a Y-direction moving means 85 for moving the pallet 86 along the Y direction.

[0024] The X-direction moving means 83 of the device supplying means 8 described above includes a motor 83a and a ball screw 83b rotated by the motor 83a, and the Y-direction moving means 85 includes a motor 85a and a ball screw 85b rotated by the motor 85a. The configuration in which the X-direction moving plate 84 is moved forward and backward in the X direction by the X-direction moving means 83 and the configuration in which the pallet 86 is moved forward and backward in the Y direction by the Y-direction moving means 85 are substantially similar to those of the processing moving means 4 described above, and therefore detailed explanations thereof will be omitted.

[0025] The pallet 86 is formed in a flat plate shape, and contains devices 16 on its surface, which is partitioned into a plurality of regions in a lattice pattern. As shown in the cross-sectional view of Fig. 4(b), the devices 16 are semiconductor chips 17 each having a plurality of bump electrodes 18 disposed on a surface 17a thereof. The pallet 86 in the embodiment shown in Fig. 1 contains 4 x 4 = 16 devices 16, which are contained in the pallet 86 with the surface 17a, on which the plurality of bump electrodes 18 are formed, facing downward and the back surface 17b facing upward.

[0026] Although a wiring diagram is omitted, the control means 100 is connected to the spatial light modulator 54 of the laser irradiation device 5 as well as to the X-direction moving means 41 and the Y-direction moving means 42 of the processing moving means 4, the rotation drive means (not shown), the X-direction moving means 83 and the Y-direction moving means 85 of the device transport means 7 and the device supply means 8. In addition, the X-direction moving means 41 and the Y-direction moving means 42 of the processing moving means 4, the rotation drive means (not shown), the X-direction moving means 83 and the Y-direction moving means 85 of the device transport means 7 and the device supply means 8 are each provided with a position detection means (not shown), so that the table 34 and the pallet 86 can be accurately moved to any coordinate position on the XY plane.

[0027] The electrode welding apparatus 1 of this embodiment has a configuration generally as described above, and the electrode welding method performed using this electrode welding apparatus 1 to weld a device 16 having a plurality of bump electrodes 18 arranged on a surface 17a of a semiconductor chip 17 to an electrode 14 of a wiring board 10 will be described below.

[0028] As described above, the device 16 to be welded to the wiring board 10 by the electrode welding method of the present embodiment includes the semiconductor chip 17 and a plurality of bump electrodes 18 on the surface 17a of the semiconductor chip 17, the semiconductor chip 17 being made of, for example, a silicon (Si) chip. Also, the surface 10a of the wiring board 10 is formed with a device mounting area 12 on which electrodes 14 are formed so as to correspond to the plurality of bump electrodes 18 of the device 16.

[0029] To carry out the electrode welding method of this embodiment, the laser irradiation device 5 described with reference to Fig. 2 is prepared. Specifically, the laser irradiation device 5 is prepared so as to include an oscillator 81 disposed in the laser irradiation device 5 for oscillating a laser beam LB having a wavelength that is absorbed by the silicon chip, a spatial light modulator 54 for adjusting the energy distribution of the laser beam LB oscillated by the oscillator 81, and control means 100 for adjusting the spatial light modulator 54 so as to uniformize the temperatures of the plurality of bump electrodes 18 by the irradiated laser beam LB (laser irradiation device preparation step).

[0030] After the laser irradiation device preparation step is performed, an electrode positioning step is performed in which the bump electrodes 18 of the device 16 are positioned corresponding to the electrodes 12 of the wiring board 10. This electrode positioning step is generally performed according to the following procedure.

[0031] First, as shown in FIG. 1, the table 34 is positioned at a carry-in / out position for carrying the wiring board 10 in and out. Next, the wiring board 10 is placed on the table 34 with the front surface 10a of the wiring board 10 facing upward and the back surface 10b facing downward, and the suction means (not shown) is operated to supply suction negative pressure to the suction holes 342 and the suction grooves 343 to support the wiring board 10. Next, the processing movement means 4 is operated to move the table 34 and position the wiring board 10 directly under the imaging means 6. The device installation area 12 and the electrodes 14 on the wiring board 10 are imaged to detect their positions, and the position information is stored in the storage unit (memory) of the control means 100 (alignment). The electrodes 14 on the wiring board 10 correspond to the multiple bump electrodes 18 formed on the device 16.

[0032] Before, after, or simultaneously with the above-mentioned alignment, the X-direction moving means 83 and the Y-direction moving means 85 of the device supplying means 8 are operated to position the pallet 86 at a predetermined position. The predetermined position is a position where the device 16 to be adsorbed contained in the pallet 86 is positioned at a predetermined adsorption position when the device transporting means 7 is operated to rotate the transport arm 75 in the direction of the arrow R3 and position the suction unit 76 at the predetermined adsorption position, as shown in FIG. 4(a). After the pallet 86 is positioned at the predetermined position in this manner, the device transporting means 7 is operated to rotate the support arm 72 in the direction shown by the arrow R3 and position it at the adsorption position, as shown in FIG. 4(a). The device 16 to be transported next is positioned directly below the suction unit 76 positioned at the adsorption position. Next, as shown in FIG. 4(b), the lifting means (not shown) of the device transporting means 7 is operated to lower the suction unit 76 in the direction shown by the arrow R4. As shown in the figure, the pallet 86 accommodates the device 16, in which a plurality of bump electrodes 18 are formed on the front surface 17a of the semiconductor chip 17, with the back surface 17b facing upward, and the back surface 17b of the semiconductor chip 17 is accommodated in the step portion 763 of the suction portion 76. Next, the suction means described above is operated to supply a suction negative pressure V to the suction hole 764. This causes the back surface 17b of the semiconductor chip 17 to be sucked onto the suction portion 76, and as a result, the device 16 is sucked by the suction portion 76. Next, the transport arm 75 is raised, and as shown in FIG. 5, the transport arm 75 is rotated in the direction indicated by the arrow R5 to position the suction portion 76 directly below the condenser 55.

[0033] The suction portion 76 is positioned directly under the condenser 55, and the processing movement means 4 is operated to move the table 34 in the direction indicated by the arrow R6 in FIG. 5. More specifically, based on the position information of the device installation area 12 and the electrodes 14 of the wiring board 10 detected by the alignment, the electrodes 14 of the device installation area 12 of the wiring board 10 are positioned directly under the condenser 55 of the laser irradiation device 5. As a result, the device 16 and the device installation area 12 of the wiring board 10 are positioned directly under the condenser 55 in a plan view, and the multiple bump electrodes 18 formed on the surface 17a of the semiconductor chip 17 of the device 16 are positioned corresponding to the electrodes 14 formed in the device installation area 12. Then, the transport arm 75 of the device transport means 7 is lowered, and the bump electrodes 18 of the device 16 are brought into contact with the electrodes 14 formed in the device installation area 12 of the mounting board 10. This completes the electrode positioning process.

[0034] After the electrode positioning step described above is performed, an electrode welding step is performed in which a laser beam is irradiated onto the rear surface 17b of the semiconductor chip 17 to weld the bump electrodes 18 of the device 16 to the electrodes 14 of the wiring board 10. More specifically, device information is first input in advance to the control means 100 via the input means 110. Note that the input means 110 for inputting the device information is not necessarily an essential component, and may be obtained through a communication network or the like. The device information includes information on the dimensions of the device 16, information on the positions of the bump electrodes 18 formed on the front surface 17a of the semiconductor chip 17, and information on the material, thickness, etc. of the semiconductor chip 17. Based on this information, as shown in Figure 6(a), the above-mentioned Z-direction moving means of the processing moving means 4 is operated to adjust the position of the collector 55 in the Z direction, and the laser irradiation device 5 is operated to send an instruction signal from the control means 100 to the spatial light modulator 54, and the above-mentioned oscillator 51 oscillates a laser beam LB and guides it to the spatial light modulator 54, and the spatial light modulator 54 irradiates a laser beam LB0 with the energy distribution of the laser beam LB adjusted, which is irradiated onto the back surface 17b of the semiconductor chip 17, as shown in Figure 6(b).

[0035] A continuous wave (CW) laser beam LB oscillated by the laser irradiation device 5 of this embodiment is adopted, and is set to, for example, the following processing conditions. Wavelength: 400~1100nm Average output: 80~300W / cm 2 As for the wavelength of the laser beam LB, since the semiconductor chip 17 of this embodiment is made of silicon (Si), it is preferable to set it to 900 to 1000 nm, which suppresses reflection on the surface 17a of the semiconductor chip 17 and ensures absorption into silicon (Si).

[0036] According to the above-described embodiment, as can be understood from the conceptual diagram of Fig. 6(b), the laser beam LB0 irradiated from the back surface 17b of the semiconductor chip 17 selectively adjusts the heating area of ​​the semiconductor chip 17 as shown by LB1 to LB7, brings the bump electrodes 18 to a uniform melting temperature, and electrically connects the bump electrodes 18 to the electrodes 14 formed in the device mounting area 12 of the wiring board 10. As a result, the device 16 is welded to the wiring board 10, and the table 34, together with the wiring board 10, supports the device 16 with the bump electrodes 18 positioned corresponding to the electrodes 14 of the wiring board 10. With the above, the electrode welding process is completed.

[0037] When the above-mentioned electrode welding process is completed, the suction negative pressure supplied to the suction unit 76 is stopped, the above-mentioned lifting means of the device transport means 7 is operated to raise the suction unit 76 together with the transport arm 75, and the processing movement means 4 is operated to position the table 34 at the carry-in / out position where the table 34 is positioned in FIG. 1. Next, the suction means connected to the table 34 is stopped to carry out the wiring board 10 integrated with the device 16. Next, the unprocessed wiring board 10 to which the device 16 is not welded is placed on the table 34 and supported by suction. When the wiring board 10 is supported on the table 34, the above-mentioned electrode positioning process and electrode welding process are performed. By repeating this, the remaining devices 16 housed in the pallet 86 can be welded to the wiring board 10.

[0038] According to the embodiment described above, the heating area of ​​the semiconductor chip constituting the device 16 is selectively adjusted by the spatial light modulator 54, 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 board 10. This solves the problem of the multiple bump electrodes 18 being melted non-uniformly. [Explanation of symbols]

[0039] 1: Electrode welding device 2: Base 2A: Guide rail 3: Holding means 31:X direction movable plate 32: Guide rail 33: Y direction movable plate 34: Table 341: Holding surface 342: Suction hole 4: Processing movement means 41:X direction movement means 42:Y-direction movement means 5: Laser irradiation device 51: Oscillator 52: Attenuator 53: Reflective mirror 54: Spatial light modulator 55: Concentrator 6: Imaging means 7: Device transport means 71: Casing 72: Support arm 73: Motor 74: Disk 75: Transport arm 76: Adsorption part 761: Frame 762: Through hole 763: Step 764: Suction hole 8: Device supply means 81: Support stand 82:Support base 82A: Guide rail 83:X direction movement means 83a:Motor 83: Ball screw 84:X direction moving plate 85:Y-direction movement means 85a:Motor 85b: Ball screw 86: Palette 9:Display means 10: Wiring board 12: Device installation area 14: Electrode 16: Device 21:Frame body 21a: Vertical wall 21b:Horizontal wall part 100: Control means 110: Input means

Claims

1. 1. An electrode welding method for welding a device having a plurality of bump electrodes disposed on a surface of a semiconductor chip made of silicon to an electrode of a wiring board, comprising the steps of: a laser irradiation device preparation step of preparing a laser irradiation device including: an oscillator that oscillates a laser beam having a wavelength of 900 to 1000 nm that is absorbent for the semiconductor chip; a spatial light modulator that adjusts the energy distribution of the laser beam oscillated by the oscillator in correspondence with each of the plurality of bump electrodes; and control means that adjusts the spatial light modulator so as to uniformize the heating temperature of the plurality of bump electrodes by the irradiated laser beam; an electrode positioning step of positioning the bump electrodes corresponding to the electrodes of the wiring board; and an electrode welding step of operating the spatial light modulator to irradiate the laser beam from the back surface of the semiconductor chip while adjusting the energy distribution of the laser beam to uniformly correspond to each of the plurality of bump electrodes, thereby welding the bump electrodes of the device to the electrodes of the wiring board.

2. An electrode welding apparatus for welding a device having a plurality of bump electrodes disposed on a surface of a semiconductor chip made of silicon to an electrode of a wiring board, comprising: a laser irradiation device including: an oscillator that oscillates a laser beam having a wavelength of 900 to 1000 nm that is absorbent for the semiconductor chip; a spatial light modulator that adjusts the energy distribution of the laser beam oscillated by the oscillator in correspondence with each of the plurality of bump electrodes; and control means that adjusts the spatial light modulator so as to uniformize the heating temperature of the plurality of bump electrodes by the irradiated laser beam; a table for supporting a wiring board and a device having bump electrodes positioned corresponding to the electrodes of the wiring board; a processing movement means for relatively moving the laser irradiation device and the table; An electrode welding device comprising:

3. 3. The electrode welding apparatus according to claim 2, further comprising a condenser for condensing the laser beam whose energy distribution has been adjusted by the spatial light modulator.

Images