JP2002076043A - Bump forming method, semiconductor device, and bump forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bump forming method, a semiconductor device, and a bump forming device, for forming a solder bump at a terminal electrode with no cleaning. SOLUTION: There are provided a solder particle discharge process where a molten solder particle 3 is discharged toward an electrode 1 provided at a solder chip 2, and an irradiation process where, after the solder particle is discharged, the solder particle 3 and the electrode 1 are irradiated with laser beam 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a bump forming method,
More specifically, the present invention relates to a bump forming method capable of efficiently forming a solder bump on an electrode of an electronic component such as a semiconductor chip or a circuit board, and a semiconductor chip and a circuit manufactured by the method. The present invention relates to a semiconductor device connected to a substrate and a bump forming device.

[0002]

2. Description of the Related Art In mounting a semiconductor chip such as an LSI chip, there is a step of connecting a terminal electrode of the semiconductor chip to a terminal electrode provided on a mounting substrate. In this connection step, roughly, a method of connecting the solder bumps formed on the terminal electrodes of the mounting board to the terminal electrodes of the semiconductor chip, and connecting the terminal electrodes of the mounting board and the terminal electrodes of the semiconductor chip by wire bonding Method is used. In the connection method by the wire bonding, since the bump is formed by the complicated movement of the capillary, the time required for forming the connection portion is long. In addition, since the dimensions of the bump electrode substantially depend on the wire diameter of the above wire bonding, it is necessary to use a small diameter wire in order to form a small diameter bump electrode corresponding to a fine pitch, and the material cost tends to be expensive. there were. Therefore, when a multi-pin, fine-pitch bump electrode is formed by wire bonding, productivity is low and high cost is required.

For this reason, various methods have been proposed for connecting the terminal electrodes of the semiconductor chip and the terminal electrodes on the mounting board with solder bumps in order to use the mounting area efficiently. For example, as shown in FIG. 10, there is proposed a method of (a) heating a pad with a laser beam, supplying a metal powder to the heated pad, and melting and solidifying the pad to form a solder bump (Japanese Unexamined Patent Publication No. -44036). In this method, an electrode 101 formed on a semiconductor chip 102 is locally heated by a laser irradiation device 105, a metal powder 118 supplied to the heated portion is melted, and then solidified to form a solder bump 109. I do. In the semiconductor device illustrated in FIG. 10, the surface other than the portion where the bump is formed is covered with the insulating film 117.

(B) A printing method in which cream solder is thinly applied to the surface of a work in advance, and a laser beam is applied only to the pad to melt and solidify it in a spot, thereby removing the remaining applied cream solder. (JP-A-9-82716). There is also known a printing method (c) in which a bump electrode is formed by printing a paste-like bump material on an electrode land. (D) Further, a method is used in which molten solder is discharged onto a pad by a solder jet nozzle to form a solder bump.

[0005]

However, FIG.
In the method (a) shown in (1), the metal powder is supplied as a raw material for the solder, so that it tends to be excessively supplied, and a step of removing the excessive portion is required. Further, the time required for the metal powder to melt and solidify is relatively long, and it is not possible to efficiently form solder bumps. It is inevitable that the amount of heat input to the terminal electrode portion also increases, which is not desirable from the viewpoint of deformation prevention and power efficiency. Regarding the methods (b) and (c),
An additional step of removing and cleaning the remaining cream solder is required.

On the other hand, a predetermined amount of molten solder droplet is discharged to a pad by a solder jet nozzle (d).
According to the method (1), efficient bump formation is possible, but there are cases where the bonding strength between the solder and the pad varies. For this reason, it is necessary to provide a step of applying a flux to the pad, reflowing and cleaning the pad to eliminate the variation in the bonding strength. When the step of applying the flux, reflowing and washing as described above is provided, the efficiency is reduced and there is a problem in cost.

Accordingly, the present invention provides a bump forming method capable of forming a solder bump on a terminal electrode without cleaning.
It is an object to provide a semiconductor device and a bump forming device.

[0008]

According to the bump forming method of the present invention, there are provided a solder particle discharging step of discharging molten solder particles toward an electrode provided on an electronic component, and a step of discharging the solder particles after the solder particle discharging step. Irradiating the particles and the electrodes with a laser beam.

According to the above-described structure, by irradiating the laser to the solder particles and the electrodes, the temperature of the both can be increased, and the surface can be brought into a surface state in which good bonding can be performed. Therefore, a solder bump having high bonding strength can be formed without cleaning by a short heating process. Since this heating process can be performed locally with high precision and small heat input,
There is no large deformation. The above-described forming method does not need to add a new step or the like, and can be performed efficiently without obstructing the flow of the production line. For this reason, it is possible to adapt to the formation of bumps on fine-pitch multi-pin electrodes, and it is possible to improve the production efficiency, improve the production yield, and reduce the production cost. In addition,
The electronic components include a semiconductor chip, a circuit (mounting) substrate, and the like.

In the bump forming method of the present invention, in the irradiation step, for example, the irradiation of the laser beam to the vicinity of the bottom of the solder particle and the irradiation of the laser beam to the electrode are performed in succession.

With the above structure, the laser beam is moved within a short time, and both the solder particles and the electrodes are irradiated one after another. The movement of the laser beam may be a reciprocating movement. When the irradiation timing is determined based on the time before the solder particles collide with the electrode, the laser beam may be swung between the electrode and a position corresponding to the time before the collision.

In this irradiation, it is possible to adjust the level of irradiation to the solder particles and to adjust the distribution of irradiation to the electrodes and the solder particles. As a result, it is possible to set appropriate irradiation contents according to each case such as a case where importance is attached to the bonding strength and a case where importance is attached to the work efficiency.

In the bump forming method of the present invention, in the irradiation step, for example, the laser beam irradiates the electrodes and also irradiates the solder particles flying into the laser beam.

In this configuration, the laser beam irradiates the electrode exclusively, and the solder particles are heated after entering into the laser beam to have a predetermined surface state. in this case,
Since the laser beam hardly needs to be moved, the present invention can be implemented very easily. When short-wavelength light is used, the electrode surface can be cleaned and cleaned.

In the bump forming method of the present invention, in the solder particle discharging step, it is preferable that the solder particles are discharged toward an electrode surrounded by an inert gas atmosphere.

Since the electrodes are surrounded by an inert gas atmosphere and the solder particles also enter the inert gas atmosphere at least before collision with the electrodes, the laser irradiation is performed in the inert gas atmosphere. Therefore, there is no formation of an oxide film, and a solder bump having high bonding strength can be efficiently formed without cleaning.

In the bump forming method of the present invention, in the solder particle discharging step, preferably, the volume of the discharged solder particle is made equal to the volume of the solder bump formed on the electrode.

Since one solder particle forms a solder bump, a highly reliable solder bump can be formed at a high throughput.

In the bump forming method of the present invention, in the solder particle discharging step, for example, a plurality of solder particles are discharged toward the electrode, and one of the solid solder particles forms one solder bump of the electrode.

Depending on the semiconductor device, a large bump may be formed. Even in such a case, a plurality of solder particles can be flexibly combined to form a solder bump.

In the bump forming method of the present invention, in the irradiation step, the irradiation can be performed with the laser beam diameter smaller than the diameter of the solder particles.

The solder particles irradiated by this small-diameter laser beam are rapidly heated to a high temperature at a local portion. For this reason, expansion or the like occurs locally, and the oxide film of the solder particles is broken, so that the wettability on the electrode is improved, and the bonding surface is largely spread to form a bonding surface. For this reason, a stronger bonding surface can be obtained.

In the bump forming method of the present invention, it is preferable that, in the irradiation step, the laser beam is made to pass through a laser beam introduction path for guiding the laser beam to near the electrode, and then to reach the irradiation position.

With this configuration, if the laser beam introduction path is made compact, the entire bump forming apparatus can be downsized. In addition, since the laser beam can be irradiated to the solder bump formation position with high accuracy, a solder bump having excellent uniformity can be formed.

In the bump forming method of the present invention, the irradiating step includes irradiating the reflecting surface provided on the electronic component having the electrode with a low-power laser beam, and monitoring the reflected light, thereby forming a path of the laser beam. Preferably, the method further includes a step of correcting at least one of the position of the electronic component.

With the above configuration, the laser irradiation position can be constantly maintained at an appropriate position. Therefore, accurate solder bump formation can be performed continuously and stably for a long time, so that it is possible to achieve an improvement in production efficiency, an improvement in yield, and the like.

The bump forming method of the present invention may further include a heating step of heating at least the electrode portion to which the solder particles have adhered after the irradiation step and after the solder particles have adhered to the electrode.

By this heating, (a) solder particles are deformed to increase the bonding surface with the electrode, thereby improving the bonding strength;
And (b) the improvement of the bonding strength due to the growth of the metal compound between the solder and the electrode. In particular, the factor (b) has a meaning of complementing the case of the present invention because the heating time is short and the metal compound does not grow significantly.

In the bump forming method of the present invention, it is desirable that the heating in the heating step is performed by heating for the purpose of performing another process after forming the solder particles on the electrodes.

The bonding strength between the solder bump and the electrode can also be increased by a heat treatment performed later.
Therefore, the joining strength can be further increased without particularly providing a heat treatment.

In the bump forming method of the present invention, in the heating step, it is desirable to heat in a reflow furnace in an atmosphere having an oxygen concentration of 100 ppm or less.

In this configuration, since the heating is performed in an atmosphere in which oxidation does not occur, it is possible to improve the bonding strength by increasing the bonding surface due to the above factor (a).

In the bump forming method of the present invention, in the heating step, heating is performed, for example, by blowing a heated inert gas.

Also in this configuration, since the heating is performed without oxidation, the above-described improvement in the bonding strength can be obtained. In this configuration, since there is no need to have facilities such as a reflow furnace, the improvement in the bonding strength can be easily obtained.

The bump forming method of the present invention may further include a cleaning step of irradiating the electrode surface with at least one of short-wavelength light and inert gas plasma to clean the electrode surface before the step of discharging the solder particles.

By making the electrode surface a clean surface,
The effect of laser irradiation or inert gas blowing on the bonding strength can be made more reliable.

The semiconductor device of the present invention is a semiconductor device in which electrodes of a circuit board and electrodes of a semiconductor chip are connected by solder bumps. This semiconductor device has a reflection surface for reflecting light on at least one surface of a circuit board and a semiconductor chip provided with electrodes.

This reflecting surface is used for monitoring the laser beam path or the position of the electronic component during laser irradiation. Since no problem occurs even if the semiconductor device is arranged without removing the semiconductor device, the semiconductor device can be manufactured without providing a removing process.

According to the bump forming apparatus of the present invention, an electronic component support for supporting an electronic component, a discharge head for discharging molten solder particles toward an electrode of the electronic component supported by the electronic component support, A laser beam irradiation device for irradiating the solder particles and the electrodes with a laser beam;

By using this bump forming apparatus,
A bump having high bonding strength and excellent reliability can be formed without cleaning. According to this forming apparatus, the bump can be easily formed with high efficiency without adding an extra step and without obstructing the flow of the production line.

The bump forming apparatus of the present invention preferably further comprises an inert gas nozzle for blowing an inert gas to the electrode.

An inert gas is blown from the inert gas nozzle to the periphery of the electrode portion to form an inert gas atmosphere, thereby assisting the operation of laser beam irradiation and more reliably forming a highly reliable bump without cleaning. Enable.

The bump forming apparatus of the present invention preferably further includes a condensing device for narrowing the laser beam diameter to the diameter of the solder particles or less.

By narrowing the laser beam diameter to a value equal to or smaller than the diameter of the solder particles, the solder particles can be locally heated rapidly, and the surface coating at that portion can be broken immediately before the collision with the electrode.
Therefore, the impact that collides with the electrode spreads over the electrode due to the impact, and the bonding surface can be formed wider.

The bump forming apparatus of the present invention desirably further includes a laser beam introduction path for guiding the laser beam to near the electrodes.

According to this configuration, the irradiation position of the laser beam can be set with high accuracy, and the size of the bump forming apparatus can be reduced.

The bump forming apparatus of the present invention has a through hole for the discharged solder particles, a laser beam introduction path, and an inert gas introduction port, and forms an inert gas atmosphere surrounding the electronic component. It is desirable to further include a translucent cover.

By providing such a translucent cover, the laser irradiation position can be set with high accuracy, the effect of laser irradiation can be ensured, and a more reliable solder bump can be formed without cleaning. .

The bump forming apparatus of the present invention desirably includes a correction device that receives light reflected from the electronic component and corrects at least one of the path of the laser beam and the position of the electronic component. .

With this correction device, it is possible to stably guide and irradiate a laser beam at an accurate position for a long time. As a result, it is possible to obtain high production efficiency and good yield, and to reduce manufacturing costs.

[0051]

Next, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1) FIG. 1 is a diagram showing a solder bump forming method according to Embodiment 1 of the present invention.
In FIG. 1, a semiconductor chip 2 having electrodes 1 formed thereon is:
It is arranged to face a discharge head 4 that discharges the molten solder particles 3. A laser beam 6 emitted from a laser oscillator 5 is irradiated to the molten solder 3 and the electrode 1 for a short time while blowing an inert gas 8 from a gas nozzle 7 to locally form an inert gas atmosphere near the electrode. The molten solder 3 is attached to the electrode 1 to form a bump. In the above configuration, the molten solder 3 has a volume for one solder bump.

Next, the function of each of the above components will be described in more detail. The semiconductor chip 2 on which the electrodes 1 are formed is disposed facing a discharge head 4 for discharging the molten solder 3 with a gap length a therebetween. Discharge head 4
The temperature of the molten solder 3 gradually decreases while flying over the gap length a, the melting solder cuts its melting point, undergoes a phase of supercooling, and undergoes a phase transformation from the surface to a solid phase. When the gap length is relatively short, for example, on the order of several mm, the molten solder 3 does not completely transform into a solid phase but contains a molten phase. By blowing the inert gas 8, the growth of the oxide film on the surface of the molten solder 3 is suppressed, and the solid phase film is broken by the impact of the collision with the electrode 1, and the solid phase film is wetted and spread on the electrode 1.

If no laser irradiation or the like is performed as in the conventional method, the spread of the wettability to the electrode 1 is insufficient, and a large amount of oxide is interposed between the electrode and the solder. Metal compounds are not sufficiently formed.

On the other hand, according to the embodiment of the present invention, the molten solder 3 and the electrode portion 1 are rapidly heated by the laser beam 6 and solidified together with the blowing of the inert gas, so that the bonding surface is enlarged. In addition, the amount of intervening oxides can be reduced, and the metal compound between the electrode portion 1 and the solder can be formed densely. As a result, it is possible to form the bumps 9 having sufficiently high bonding strength.

As the inert gas 8, nitrogen gas (N ₂ )
In addition to an inert gas such as hydrogen gas, a gas that reduces oxides such as hydrogen gas (H ₂ ) may be included. The temperature of the inert gas may be room temperature, may be higher than room temperature, or may be lower. As described in the first embodiment, a short-time heating by laser irradiation and rapid solidification can form a bump having high bonding strength without washing. Further, in the example shown in FIG. 1, the volume of one molten solder particle matches the volume of one solder bump without excess or shortage, so that a solder bump can be formed with high throughput. It is desirable that the surface of the electrode 1 be cleaned in advance with short-wavelength light or plasma gas.

(Embodiment 2) FIG. 2 is a diagram showing a solder bump forming method according to Embodiment 2 of the present invention.
In FIG. 2, there are two molten solder particles that adhere to the electrode 1 to form a solder bump. However, in general, the number of molten solder particles that form a solder bump is not limited to two, but may be two.
More than the number may adhere to the electrodes to form solder bumps. By forming one bump with a plurality of solder grains in this way, the bump can be flexibly formed according to the type of the semiconductor chip or the like.

(Embodiment 3) FIG. 3 is a diagram showing a method of forming solder bumps according to Embodiment 3 of the present invention.
In FIG. 3, the laser beam 6a is condensed by the condenser lens 10 to a beam diameter smaller than the size of the solder particle 3. By irradiating the solder particle 3 with the laser beam 6a having this small beam diameter, the surface of the solder particle can be locally and rapidly heated. For this reason, a part of the solder particles is locally heated, and a part of the solder particles is locally expanded in volume to break the oxide film on the surface. Therefore, after this, when the solder particles collide with the electrodes, they can be sufficiently wetted and spread. As a result, the interposition of oxides and the like can be reduced, the metal compound between the solder and the electrode can be sufficiently formed, and a solder bump having high bonding strength without cleaning can be formed.

(Embodiment 4) FIG. 4 is a diagram showing a method of forming solder bumps according to Embodiment 4 of the present invention.
In the figure, a laser beam 6 is reflected by two reflecting surfaces 11 facing each other in parallel, is reflected a plurality of times between the reflectors, is guided to an electrode, and irradiates the electrode. As described above, the gap length a between the ejection head 4 and the semiconductor chip 2 can be reduced by providing the laser beam introduction path by the reflection surface to the electrode. By shortening the gap length a, the size of the above-mentioned solder bump forming apparatus can be reduced, and the accuracy of the laser irradiation position with respect to the electrodes can be increased. As a result, the accuracy of the solder bump formation position can be improved. it can. Portions other than the above-described laser beam introduction path are the same as those described in the first embodiment, and thus description thereof will be omitted.

(Embodiment 5) FIG. 5 is a diagram showing a solder bump forming method according to Embodiment 5 of the present invention.
In this embodiment, the translucent cover 12 has a hole 12a through which the molten solder passes, and includes a reflective film 12b that can guide the laser beam to a desired position. further,
An inert gas introduction hole 12c is provided, and an inert gas is introduced and covered between the translucent cover and the semiconductor chip through the inert gas introduction hole 12c to form an inert gas atmosphere. In this inert gas atmosphere, solder particles can be adhered while irradiating a laser beam, so that solder bumps having high bonding strength can be formed without cleaning. Portions other than the light-transmitting cover 12 are the same as those in the first embodiment, and a description thereof will be omitted.

(Embodiment 6) FIG. 6 is a diagram showing a solder bump forming method according to Embodiment 6 of the present invention.
In FIG. 1, the semiconductor chip 2 is provided with a reflective film 13 for alignment. In the present embodiment, the irradiation position is periodically measured by using the alignment reflective film 13 to accurately grasp the irradiation position of the laser beam that fluctuates with time and correct the deviation of the irradiation position. I do. First, the output of the laser beam is set to a low level that does not damage the semiconductor chip and is within the sensitivity of the position sensor. The laser beam 6b from the laser oscillator 5 having the low output is applied to the alignment reflective film 13 described above.
And the reflected light is detected by the position sensor 17 to grasp the spot position. The feedback system 25 operates based on this information, and the drive system 18 drives the reflection mirror 19 to correct the amount of displacement.

By correcting the deviation of the laser beam irradiation position online, the laser beam irradiation to the electrodes and the solder particles can be stably performed for a long time.

(Embodiment 7) FIG. 7 is a diagram showing a method of forming solder bumps according to Embodiment 7 of the present invention.
In the figure, a semiconductor chip 20 on which solder bumps are formed is placed in a reflow furnace 14 in an atmosphere having an oxygen concentration of 100 ppm or less, and passes while being heated. Since the heating by the reflow furnace is performed in a low oxygen concentration atmosphere, the solder can be deformed and the bonding surface between the electrode and the solder can be enlarged without forming an oxide film. In addition, the heating allows the metal compound to grow. Therefore, a solder bump having a higher bonding strength can be formed without cleaning.

(Embodiment 8) FIG. 8 shows a method of forming solder bumps according to Embodiment 8 of the present invention.
In the figure, the solder discharged from the discharge nozzle and attached to the electrode portion while being irradiated with the laser is heated by the high-temperature inert gas 15 from the gas nozzle 7. By the heating in the inert gas atmosphere, the solder can be deformed without the interposition of the oxide film, and the joint surface between the electrode portion and the solder can be enlarged. In addition, the heating allows the metal compound to grow. As a result, a stronger joint between the electrode portion and the solder can be formed without cleaning.

(Embodiment 9) FIG. 9 is a diagram showing a solder bump forming method according to Embodiment 9 of the present invention.
In the figure, a semiconductor chip 20 having solder bumps 9 formed thereon is flip-flop bonded to a circuit board 16. At the time of this flip-flop bonding, the solder bump 9
Are heated for connection with terminals (not shown) of the circuit board. This heating also heats the solder bumps near the electrodes 1 of the semiconductor chip. By the heating in the subsequent step, the bonding surface between the electrode 1 of the semiconductor chip and the solder bump is enlarged, and a stronger bonding portion is formed without cleaning.

(Embodiment 10) Embodiment 1 of the present invention
A value of 0 targets the formation of solder bumps on electrodes (not shown) of the circuit board. The formation of the solder bumps on the electrodes of the circuit board, that is, the mounting board, can be performed using the same method as the formation of the solder bumps on the electrodes of the semiconductor chip in the first to ninth embodiments.
That is, by applying laser irradiation to the electrodes of the circuit board, it is possible to form strong solder bumps without cleaning.

Although the embodiments of the present invention have been described above, the embodiments of the present invention disclosed above are merely examples, and the scope of the present invention is not limited to these embodiments. Not limited. The scope of the present invention is shown by the description of the claims, and further includes all modifications within the meaning and scope equivalent to the description of the claims.

[0068]

By using the bump forming method of the present invention, a highly reliable solder bump without cleaning can be formed on an electrode of a semiconductor chip or a circuit board. The above bump formation method not only improves the quality of the bump,
Since it can be easily performed without providing a new additional step and without obstructing the flow of the production line, high efficiency, high yield, and reduction in production cost can be obtained.

[Brief description of the drawings]

FIG. 1 is a view showing a step of irradiating a molten solder particle and an electrode of a semiconductor chip with laser while blowing an inert gas in the method of forming a solder bump according to the first embodiment of the present invention.

FIG. 2 is a diagram illustrating a case where a plurality of melted solder particles gather to form one solder bump in the solder bump forming method according to the second embodiment of the present invention.

FIG. 3 is a view showing a step of concentrating a laser beam and irradiating a laser beam having a diameter smaller than a molten solder particle to an electrode of a semiconductor chip in a solder bump forming method according to a third embodiment of the present invention; It is.

FIG. 4 is a view showing a step of irradiating a laser beam to a molten solder particle and an electrode of a semiconductor chip via a path for guiding a laser beam in the solder bump forming method according to the fourth embodiment of the present invention.

FIG. 5 is a view showing a step of introducing an inert gas into a translucent cover and performing laser beam irradiation in an inert gas atmosphere in the solder bump forming method according to the fifth embodiment of the present invention.

FIG. 6 shows a method of forming a solder bump according to a sixth embodiment of the present invention, in which a low-output laser beam is applied to a reflective film for alignment provided on a semiconductor chip, and reflected light is detected by a position sensor to correct an irradiation position. It is a figure which shows the process performed.

FIG. 7 shows a method for forming a solder bump according to a seventh embodiment of the present invention, in which a semiconductor chip provided with solder bumps is reflow-heated to enlarge a bonding surface between a solder and an electrode, and a metal compound is grown to increase a bonding strength. FIG. 4 is a view showing a step of improving the density.

FIG. 8 is a cross-sectional view illustrating a method of forming a solder bump according to an eighth embodiment of the present invention. It is a figure which shows the process of growing and improving a joining strength.

FIG. 9 is a view showing a method of forming a solder bump according to a ninth embodiment of the present invention, in which a semiconductor chip provided with solder bumps is heated when flip-chip bonded to a circuit board to enlarge a bonding surface between a solder and an electrode; FIG. 4 is a diagram illustrating a process of improving a bonding strength by growing a metal compound.

FIG. 10 is a diagram illustrating a conventional solder bump forming method.

[Explanation of symbols]

1 electrode part, 2 semiconductor chip (electronic parts), 3 solder particles, 4 solder discharge head, 5 laser oscillator, 6
Laser beam, 6a laser beam focused to a diameter smaller than the solder grain, 7 gas nozzle, 8 inert gas,
9 solder bump, 10 condenser lens, 11 reflecting surface,
12 Translucent cover, 12a Solder grain passage hole, 12b
Reflective surface, 12c inert gas introduction hole, 13 reflective film for alignment, 14 reflow furnace, 15 high temperature inert gas, 16 circuit board (electronic parts), 17 position sensor, 18 drive system, 19 reflecting mirror, 20
Semiconductor chip with bumps formed, 25 feedback system.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05K 3/34 505 B23K 101: 40 // B23K 101: 40 H01L 21/92 604A 604Z

Claims (21)

[Claims] 1. A solder particle discharging step of discharging molten solder particles toward an electrode provided on an electronic component, and after the solder particle discharging step, irradiating the discharged solder particles and the electrode with a laser beam. An irradiation step. 2. The bump forming method according to claim 1, wherein, in the irradiation step, the irradiation of the laser beam to the vicinity of the bottom of the solder grain and the irradiation of the laser beam to the electrode are performed in succession. 3. The bump forming method according to claim 1, wherein, in the irradiating step, the laser beam irradiates the electrode and also irradiates solder particles flying into the laser beam. 4. The bump forming method according to claim 1, wherein in the solder particle discharging step, the solder particles are discharged toward the electrode surrounded by an inert gas atmosphere. 5. The bump forming method according to claim 1, wherein in the solder particle discharging step, the volume of the discharged solder particles is made equal to the volume of the solder bump formed on the electrode. 6. The solder particle discharging step according to claim 1, wherein a plurality of solder particles are discharged toward said electrode, and said plurality of solid solder particles form one solder bump of said electrode. The bump forming method according to any one of the above. 7. The bump forming method according to claim 1, wherein in the irradiating step, the laser beam is irradiated with a beam diameter of the laser beam smaller than a diameter of the solder particle. 8. The method according to claim 1, wherein in the irradiating step, the laser beam is caused to reach a position of the irradiation after passing through a laser beam introduction path for guiding the laser beam to near the electrode. The bump forming method according to the above. 9. The path of the laser beam and the electronic component by irradiating a low-power laser beam to a reflection surface provided on the electronic component having the electrode and monitoring the reflected light. The bump forming method according to claim 1, further comprising: correcting at least one of the positions. 10. The method according to claim 1, further comprising, after the irradiating step, a heating step of heating at least an electrode portion to which the solder particles have adhered after the solder particles have adhered to the electrode. Bump formation method. 11. The bump forming method according to claim 10, wherein the heating in the heating step is performed by heating for another processing performed after forming the solder particles on the electrode. 12. An oxygen concentration of 10 in the heating step.
The bump forming method according to claim 10, wherein the heating is performed in a reflow furnace having an atmosphere of 0 ppm or less. 13. The bump forming method according to claim 10, wherein in the heating step, heating is performed by blowing a heated inert gas. 14. The method according to claim 1, further comprising a cleaning step of irradiating the electrode surface with at least one of short-wavelength light and inert gas plasma to clean the electrode surface before the solder particle discharging step. The bump forming method according to the above. 15. In a semiconductor device in which electrodes of a circuit board and electrodes of a semiconductor chip are connected by solder bumps, at least one surface of the circuit board and the semiconductor chip provided with the electrodes reflects light to reflect light. A semiconductor device having a surface. 16. An electronic component support for supporting an electronic component, a discharge head for discharging molten solder particles toward an electrode of the electronic component supported by the electronic component support, A bump forming apparatus, comprising: a laser beam irradiation device that irradiates a laser beam to an electrode. 17. The bump forming apparatus according to claim 16, further comprising an inert gas nozzle for blowing an inert gas to said electrode portion. 18. The bump forming apparatus according to claim 16, further comprising a light condensing device for narrowing the laser beam diameter to a size equal to or smaller than the diameter of the solder particles. 19. The apparatus according to claim 1, further comprising a laser beam introduction path for guiding the laser beam to a position near the electrode.
19. The bump forming apparatus according to any one of 6 to 18. 20. A passage hole for the discharged solder particles,
20. The light-emitting device according to claim 16, further comprising a light-transmitting cover having the laser beam introduction path and the inert gas introduction port, and surrounding the electronic component to form an inert gas atmosphere. Bump forming equipment. 21. The apparatus according to claim 16, further comprising a correction device that receives reflected light from the electronic component and corrects at least one of a path of the laser beam and a position of the electronic component. 3. The bump forming apparatus according to claim 1.