JP3350529B1 - Solder joining apparatus and solder joining method - Google Patents

Abstract

The present invention relates to a solder bonding apparatus used for bonding a solder layer to a wiring or a pad of a semiconductor device or an electronic component.
To improve the soldering throughput compared to the past, and to prevent the generation of residues on the substrate after soldering. Kind Code: A1 A magazine for accommodating a plurality of substrates W having solder layers A at intervals, a loading port 3a for storing the magazines 2 and loading the substrates W into the magazine 2, and a transport for unloading the substrates W from the magazine 2. A heating chamber 3 having an outlet 3b, and a carry-in port 3a and a carry-out port 3 for shielding the heating chamber 3 from outside air.
b, the first air shielding mechanism 8 and the second
Air shielding mechanism 9, a heater 4 arranged so as to confine the magazine 2 in the heating chamber 3, a formic acid supply mechanism 6 for supplying formic acid to the heating area, and an exhaust mechanism for discharging formic acid out of the heating chamber 3. 16 is included.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soldering apparatus and a soldering method, and more particularly, to a semiconductor device,
The present invention relates to a solder joining apparatus used for joining a solder layer to wirings and pads of an electronic component, and a solder joining method.

[0002]

2. Description of the Related Art As a method of joining solder (solder) to a metal pattern such as an electrode pad and a metal wiring of a semiconductor device, a solder is formed on a metal pattern by a plating method, a printing method, a ball mounting method, or the like. A method has been adopted in which solder is heated and melted and joined to and formed on an electrode pad.

[0003] When the solder is melted, an oxide film on the surface of the solder and the electrode pad thereunder is usually removed using a flux, and the solder is melted and joined while being cleaned. The solder bonding step using the flux is performed, for example, by the following method. First, the flux applied to the surface of the metal pattern, which is the surface on which the solder is to be applied, protects the surface of the metal pattern while activating the surface by heating, prevents oxidation, and maintains the active state. At the same time, the solder melts and spreads on the surface of the metal pattern. A part of the flux is decomposed by the melting of the solder.

[0004] Thereafter, the solder is cooled and solidified to be joined to the surface of the metal pattern. At the same time, the flux and decomposition products remaining on the metal pattern solidify. After solder bonding using such a flux, the solidified flux is removed by washing. However, at the time of washing, decomposition products cannot be easily removed with an organic solvent containing neither chlorofluorocarbon nor trichlene, so that it is necessary to use a large amount of the organic solvent used for washing.

However, since an organic solvent has an adverse effect on the environment, development of a soldering method that does not require cleaning is desired. Also, in the mounting process of the electronic component module, it is common to adopt a process of applying a flux or a flux-containing paste to a solder joint portion and then mounting. In this case, since the flux is decomposed by the heat generated during the mounting to generate harmful gases, it is necessary to ensure work safety. Further, if a halogen component remains in the module as a residue of the flux, corrosion of the wiring of the module and migration of the wiring are promoted, so that thorough cleaning is required, which causes an increase in manufacturing cost.

In order to solve these problems, the following methods or apparatuses are known. First, a soldering method using a carboxylic acid having a reducing action is described in, for example,
90584, JP-A-6-267632, JP-A-7-164141, JP-A-11-23393
No. 4, for example.

[0007]

However, the conventional soldering apparatus has the following problems. First, a first problem is to improve the throughput of solder bonding in a known solder bonding apparatus. The solder is formed on a wiring or a pad of a semiconductor substrate, a ceramic substrate, a circuit board, or the like, and then conveyed into a solder bonding apparatus, where it is heated and melted and bonded to the wiring or the pad. Such a soldering apparatus has a so-called single-wafer processing structure in which substrates are taken in and out one by one, so that the efficiency of soldering does not increase. Therefore, an apparatus in which a plurality of solder bonding areas are adjacent to each other in order to increase the processing capacity of a substrate is disclosed in
Although this is described in FIGS. 2 and 3 of Japanese Patent No. 233934, this is substantially equivalent to using a plurality of soldering apparatuses, which not only increases the cost but also requires a large area.

[0008] A second object is to prevent the generation of residues on a substrate after solder bonding. JP-A-7-1
Japanese Patent No. 64141 discloses that a mixture of a carboxylic acid and a diketone is introduced into a solder melting region at the time of solder bonding. However, the mixture supplied to the solder melting region in a liquid form has a residue on a substrate. Easily occur. The object of the present invention is
It is an object of the present invention to provide a soldering apparatus and a soldering method for improving the throughput of soldering as compared with the related art, or for preventing generation of residues on a substrate after soldering.

[0009]

An object of the present invention is to provide a magazine for accommodating a plurality of bases having a solder layer at intervals, a loading port for storing the magazines and loading the bases into the magazine, and a magazine. A heating chamber having a carry-out port for carrying out the substrate, a first air shielding mechanism and a second air shielding mechanism installed at each of the carry-in port and the carry-out port for shielding the heating chamber from outside air; A soldering device having a heater arranged so as to confine the magazine in the heating chamber, a formic acid supply mechanism for supplying formic acid to the heating area, and an exhaust mechanism for discharging the formic acid out of the heating chamber. Will be resolved.

In addition, the above-mentioned problems are a step of placing a plurality of substrates having a metal pattern to which a solder layer is attached in a magazine at intervals, and a step of covering the magazine supplied with formic acid with a heater in a heating area. Heating the solder layer by the heater to join the solder layer to the metal pattern; and introducing the cooling gas into the heater to discharge the formic acid in the heater to the outside and to remove the formic acid from the solder layer. And a step of cooling the metal pattern and the base, a step of removing the heater from around the magazine, and a step of unloading the base from the magazine.

Next, the operation of the present invention will be described. According to the present invention, since there are provided a magazine in which a plurality of bases each having a metal pattern to which a solder layer is attached at intervals and a heater arranged so as to confine the magazines, a plurality of bases are provided. Since the solder is joined at the same time, the throughput is improved as compared with the conventional case.

Further, after the solder layer is heated and melted by the heater, the heater is removed from the periphery of the magazine, so that the temperature of the solder layer can be easily lowered and the time from heating to cooling can be shortened. it can. Further, since a structure in which the cooling gas introduction mechanism is attached to the heater is employed, cooling can be performed more rapidly by the cooling gas immediately after the heating of the solder layer is completed, and the solder cooling time is shortened.

When formic acid is supplied to the solder layer, excessive supply of formic acid is suppressed by mixing two fluids of formic acid and gas, or excess formic acid can be supplied by mist-forming formic acid with ultrasonic waves. Is suppressed. In addition, since the magazine is contained only in the heating chamber, the contamination of the substrate during heating can be prevented by preventing the contaminants in the air from adhering to the magazine.

Further, since the heater and the magazine are confined in the heating chamber from the introduction of formic acid into the heater to the discharge thereof, leakage of formic acid from the heating chamber to the outside is prevented.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention. FIG. 1 is a plan view showing a solder (solder) bonding apparatus according to an embodiment of the present invention, and FIG.
FIG. 2 is a sectional view taken along line II of FIG. 1. 1 and 2, a processing magazine 2 made of stainless steel, which is moved by a magazine moving mechanism 10, is mounted on a magazine mounting table 1, and a processing magazine (transport mechanism) is provided in a moving area of the processing magazine 2. A heating and melting chamber 3 made of stainless steel and covering the housing 2 is attached.

At the center of the heating and melting chamber 3, a processing magazine 2 is provided.
A bell-shaped heater 4 with an open bottom that can be lifted higher than that is arranged. The heater 4 is constituted by one or a combination of a conduction heat heater, an infrared lamp heater, and a coil heater, and has a support shaft 5 a of a drive mechanism 5 attached to a central upper portion of the heating and melting chamber 3.
Is moved up and down. An inert gas purge nozzle 4 drawn from a nitrogen supply source (not shown) outside the heating / melting chamber 3 is provided at one or more locations above the heater 4.
a is connected.

At the center of the heating and melting chamber 3, on both sides of the processing magazine 2, formic acid spray nozzles 6 connected to a formic acid supply mechanism 7 outside the heating and melting chamber 3 are arranged. As shown in FIG. 3, formic acid spray nozzle 6 has a plurality of formic acid spray holes 6a formed toward the center of heating and melting chamber 3 on its side. A loading port 3a is provided in one of the moving directions of the processing magazine 2 in the heating and melting chamber 3, and a loading port 3b is provided in the other direction.
And the carry-out port 3b are structured to be opened and closed by shutters 8 and 9, respectively. These shutters 8, 9
The purpose is to prevent formic acid introduced into the heated and molten vagina 3 from leaking to the outside. Leakage of formic acid into the atmosphere not only gives a pungent odor to humans, but also causes an explosion due to contact of formic acid with the atmosphere.

A loader 11 for storing a wafer W to which solder in an unbonded state has been attached is placed on the magazine mounting table 1 outside the carry-in entrance 3a. Also, the exit 3b
An unloader 12 for receiving a substrate W from the processing magazine 2 is placed on the magazine mounting table 1 outside the above. Below the mounting area of the loader 11, a first pusher 13 is attached to push up the wafer W in the loader 11 from the outside of one end of the magazine mounting table 1 and into the processing magazine 2 through the loading port 3a. ing. Further, below the heating and melting chamber 3 near the carry-out port 3b, the wafer W in the processing magazine 2 rises through the opening 1a of the magazine mounting table 1 and passes through the carry-out port 3b.
A second pusher 14 for extruding into the second 2 is attached. Above or below the opening 1a, a shutter 15 for closing the opening 1a while the second pusher 14 is waiting under the magazine mounting table 1 is attached.

The first and second pushers 13 and 14 are
Elbow portions 13b, 1 which are respectively moved up and down by driving portions 13a, 14a mounted below the magazine mounting table 1.
4b, arms 13c, 14c which retreat horizontally from the elbows 13b, 14b toward the carry-in port 3a or the carry-out port 3b of the heating and melting chamber 3, and a processing magazine 2 which is vertically attached to the tips of the arms 13c, 14c. And plates 13d and 14d having a smaller width.

An exhaust device 16 for discharging gas in the heating / melting chamber 3 or in the heating / melting chamber 3 to the outside of the heating / melting chamber 3 is mounted below a region of the magazine mounting table 1 where the heater 2 is mounted. And an exhaust port (not shown) of the exhaust device 16
Is connected to a formic acid recovery mechanism 17 via an exhaust pipe 16a. When the internal space of the heater 4 covering the processing magazine 2 is depressurized, for example, a dry pump is used as the exhaust device 14, and when the internal space is set to normal pressure, for example, a sirocco fan is used.

At the ceiling of the heating and melting chamber 3, the heating and melting chamber 3
A sirocco fan 18 for introducing outside air into the inside is attached. The processing magazine 2 described above is, for example, as shown in FIG.
As shown in the figure, a frame 2a formed in a cubic shape and a frame 2
a and a plurality of horizontal bars 2b attached in a lattice shape at intervals on the both sides in the vertical direction. The horizontal bar 2b is
It has a support surface 2c protruding inside the frame 2a, and is arranged so as to support a base such as a wafer, a semiconductor substrate, and a support plate by the left and right support surfaces 2c of each stage of the horizontal bar 2b. The spacing between the supporting surfaces 2c of the horizontal bars 2b arranged vertically, that is, the slot spacing is 5 from the viewpoint of solder bump bonding.
mm or more. The space between the horizontal bars 2b also functions as a formic acid introduction space.

The loader 11 and the unloader 12 have a plurality of mounting surfaces on which wafers, substrates and the like are mounted at the same position as the support surface 2c of the processing magazine 2. Such a loader 11 and unloader 12 may employ the same structure as the processing magazine as shown in FIG. The processing magazine 2, the loader 11, and the unloader 12 face the front face without the horizontal bar 2b to the carry-in port 3a and the rear face without the horizontal bar 2b to the carry-out port 3b. Is placed. On each stage of the processing magazine 2, the loader 11, and the unloader 12, for example, a substantially circular semiconductor wafer W as shown in FIG. A plurality of solder layers A are formed on the plurality of semiconductor devices C as shown in FIG.

As shown in FIG. 6A, for example, the semiconductor device C includes an insulating film 21a formed on a semiconductor wafer W having transistors, capacitors, multilayer wiring, and other semiconductor elements, and an insulating film 21a formed on the insulating film 21a. And an electrode pad 21b formed on the substrate. The electrode pad 21b is
It is electrically connected to the semiconductor element and is exposed through the opening 21d of the insulating cover film 21c formed thereon. An underlying metal layer 21e made of titanium and nickel is formed on an exposed portion of the electrode pad 21b, and a solder layer A is formed on the underlying metal layer 21e by an electroless plating method, an electrolytic plating method, a printing method, or the like. .

The electrode pad 21b and the solder layer A are shown in FIG.
As shown in (2), there is a case where they are formed at separate positions and are electrically connected to each other via a lead-out wiring (relocation wiring) 21f. The lead wiring 21f is made of the insulating cover film 2
1c, one end of which is connected to the electrode pad 21b through the opening 21d of the insulating cover film, and the other end of which is formed through the opening 21h of the upper insulating cover film 21g which covers the lead wiring 21f. 21e and the solder layer A.

The formic acid recovery mechanism 17 described above is, for example, shown in FIG.
As shown in (a), the exhaust device 16 has a structure in which an exhaust pipe 16a is connected to a lower portion in a bathtub 17a, and an exhaust pipe 17b is connected to an upper portion of the bathtub 17a. Bathtub 17
Examples of the solution 17c that can be put in such an amount that it does not contact the lower end of the exhaust pipe 17b in a are alcohol, water, and the like. Further, a plate 17d made of a porous material or a plate 17d formed with a large number of holes 17e as shown in FIG. 7B is provided at the connection port between the exhaust pipe 16a of the exhaust device 16 and the bathtub 17a.
Is inlaid. The plate 17d turns the formic acid-containing exhaust gas introduced from the exhaust pipe 16a of the exhaust device 16 into a number of bubbles. Therefore, the formic acid-containing exhaust gas is bubbled in the solution 17c to dissolve the formic acid component in the solution, and is discharged from the exhaust pipe 17b with a low formic acid content. That is,
Since the contact area of the formic acid-containing exhaust gas with the solution 17c increases, the formic acid recovery efficiency increases, and the formic acid is recovered safely.

The processing magazine 2 is moved, the heater 4 is moved up and down, the formic acid supply mechanism 7 is driven, the exhaust device 16 is driven, the pushers 13 and 14 are driven, the shutters 15, 8 and 9 are opened and closed, and the sirocco fan 18 is driven. The control of the temperature of the heater 2 and the introduction and stop of the nitrogen gas from the inert gas purge nozzle 4a are performed by a control circuit (not shown).

Next, the method of joining the solder layer (solder bump) A and the electrode pad 21b shown in FIG. 6A by using the solder heating / melting device shown in FIGS. The method of connecting the solder layer A and the lead wiring 17f shown in FIG. 6B will be described with reference to FIGS. First, FIG.
As shown in (a), the shutter 8 at the entrance 3a of the heating and melting chamber 3 is opened, and the shutter 9 at the exit 3b is closed. Also, the elbow portions 13b of the first and second pushers 13 and 14,
14b, arms 13c, 14c, plates 13d, 14
d is lowered below the upper surface of the magazine mounting table 1. Further, the heater 4 is lifted up by the support shaft 5a in the heating and melting chamber 3 and is heated to, for example, the melting point of the solder layer A or higher.

A plurality of semiconductor wafers W spaced apart from each other
Is placed on the magazine mounting table 1 outside the loading port 3a, and the processing magazine 2 is loaded into the loading port 3a.
Put on. Subsequently, as shown in FIG. 8 (b), after the elbow 13b is raised by the drive unit 13a of the first pusher 13, the arm 13c is extended toward the loader 11, and the loader 11 is moved by the plate 13d at the tip thereof. The plurality of wafers W are transferred onto the horizontal bar 2b of each stage of the processing magazine 2 while keeping the vertical interval.

Next, as shown in FIG. 8 (c), the processing magazine 2 is moved toward the center of the heating and melting chamber 3, and at the same time, the shutter 8 of the carry-in entrance 3a is closed. Then, the movement of the processing magazine 2 is stopped when the processing magazine 2 is located immediately below the heater 4. Thereafter, the loader 11 is removed from the magazine mounting table 1. Then, the formic acid-containing gas G is sprayed toward the processing magazine 2 from the formic acid supply nozzle 6 located on the side of the processing magazine 2. This allows
In the processing magazine 2, gaseous formic acid is in a state of being floated in a gap between the wafer W and the wafer W. Gaseous formic acid is in a liquid state before being vaporized.
It is a solution in which the concentration of formic acid is set to be less than vol.% and converted into a gaseous state, thereby ensuring safety without explosion.

Next, as shown in FIG.
The processing magazine 2 is covered with the heater 4 by lowering the support shaft 5a from the above. By the heating of the heater 4, the plurality of solder layers A on each wafer W are heated and melted, and are joined to the electrode pads 21b or the lead wires 21f thereunder.
Here, the formic acid-containing gas supplied into the processing magazine 2 is further prevented from leaking outside by being surrounded by the heater 4.

In this case, the heating temperature of the heater 4 may be controlled. For example, as a first step, in order to remove an oxide film on the surface of the solder layer A by the reducing action of formic acid, the solder layer A
Is controlled to be about 50 to 90 ° C. lower than the melting point of Formic acid starts to work effectively at a temperature lower by about 50 ° C. than the melting point of the solder layer A,
The oxide film on the surface is removed. When the solder layer A is made of eutectic tin-lead, the temperature at which the reducing action by formic acid is effective is 15
0 ° C. or higher. When the solder layer A is made of a high melting point solder material, for example, tin silver, the temperature at which the reducing action by formic acid is effective is about 180 ° C. or more.

As the second stage of controlling the temperature of the heater 4, the temperature is set to the melting point of the solder layer A or higher. As a result, the temperature of the solder layer A rises, the gas generated or existing inside the solder layer A in the course of the rise gradually escapes, and the solder layer A gradually melts to form the electrode pad 21b.
Alternatively, it is joined to the lead wiring 21f. Thereby, the solder layer A
Scattering and formation defects do not occur. The shape of the solder layer A becomes as shown by the broken lines in FIGS. 6 (a) and 6 (b) by melting.

In the step of heating the solder layer A,
Since the processing magazine 2 is confined in the narrow heater 4, the temperature control in the processing magazine 2 is easy. Next, as shown in FIG.
a while introducing nitrogen gas into the interior of the heater 4;
The exhaust mechanism 16 is driven to discharge the formic acid-containing gas in the heater 4 to the nitrogen recovery mechanism 17 together with the nitrogen gas. Thus, the solder layer A is cooled and solidified, and the formic acid on the surface of the semiconductor layer A and the electrode pads 21c or the extraction wiring 21f is promoted to be removed by vaporization. At this stage, the temperature of the heater 4 may be lowered to the melting point of the solder layer A or lower. In addition,
From the inert gas purge nozzle 4a, an inert gas such as argon or neon may be introduced instead of nitrogen.

Next, as shown in FIG. 9C, the heater 4 is lifted by raising the support shaft 5a while driving the sirocco fan 18 on the ceiling of the heating and melting chamber 3. Thus, the processing magazine 2 is exposed in the heating and melting chamber 2, and the gas remaining in the processing magazine 2 is driven by the exhaust mechanism 16 and exhausted to the formic acid recovery mechanism 17. As a result, formic acid slightly diffused into the heating and melting chamber 3 is also exhausted, and the semiconductor wafer W in the processing magazine 2 is further cooled to approach room temperature.

Thereafter, the sirocco fan 18 and the exhaust device 16 are stopped. Thereafter, as shown in FIG. 10 (a), the processing magazine 2 is moved to the outlet 3b. Next, as shown in FIG. 10 (b), the elbow 14b of the second pusher 14 is lifted, and the shutter 9 of the carry-out port 3b is opened.

Then, as shown in FIG. 10 (c), the arm 14c of the second pusher 14 is extended toward the carry-out port 3b, and the processing magazine 2 is moved by the plate 14d at the tip.
Are extruded and transferred to the unloader 12. Before closing the shutter 9 of the loading port 3b and attaching the processing magazine 2 to the loading port 3a, a new wafer W
Is mounted outside the shutter 8 at the entrance 3 of the heating and melting chamber 3.

As described above, one cycle of processing from the loading and unloading of the semiconductor wafer W in the heating and melting chamber 3 is completed, and such a series of processing is repeatedly performed. According to the above-described series of operations, the soldering on a plurality of wafers can be simultaneously performed by one solder heating and melting process, so that the throughput is improved as compared with the conventional single wafer processing. In addition, since the solder layer A is forcibly placed in a flow of nitrogen (inert) gas after the solder layer A is heated and melted, not only can the temperature of the solder layer A be rapidly lowered and cooled, but also the processing can be performed. Formic acid in the magazine 2 can be recovered in a short time, and the reaction product gas present on the surface of the solder layer A can be removed and recovered by the flow of nitrogen gas.
As a result, when the solder layer A is cooled, the reaction product gas is prevented from solidifying and adhering to the surface of the solder layer A as a residue. Such a residue causes reoxidation of the solder layer A.

Further, according to the above-described solder heating / melting apparatus, the heater 4 for heating the solder has a mechanism for confining the processing magazine 2 in the heater 4 at the time of heating by raising and lowering the solder. It is possible to quickly raise the temperature of the layer A and quickly release the solder layer A from heating. In addition, since the processing magazine 2 is confined in the heater 4 so as to surround the processing magazine 2 from the side, heat is well transmitted to the center of the processing magazine 2 and the distribution of heat in the heater is substantially uniform, so that the semiconductor wafer Heat unevenness due to the difference in position on the W upper surface is eliminated.

Further, the heater 4 is provided for each cycle described above.
Since the formic acid in the heating and melting chamber 3 is recovered, the plurality of semiconductor wafers W are transferred from the inside of the heating and melting chamber 3 to the unloader 12 or in the next cycle.
During the transfer of the formic acid from the loader 11 into the heating / melting chamber 3, formic acid does not leak out of the heating / melting chamber 3, thereby preventing environmental pollution.

When a dry pump is used as the exhaust mechanism 16, the inside of the heater 2 is depressurized by the dry pump while the processing magazine 2 is covered by the heater 4. Further, in the above description, the formic acid supply nozzle 6 is located on the side of the heater 2, but is arranged so as to enter the inside of the heater 2 so that the amount of formic acid which spreads in the heating and melting chamber 3 is reduced in advance. Is also good.

The above-mentioned heating and melting of the solder layer A is performed to join the solder layer A to the pad or the wiring. However, when the pad of the semiconductor chip and the wiring of the circuit board are joined via the solder. Also, the above-described solder heating and melting device may be used. FIG. 11 shows a case where the semiconductor wafer C shown in FIG. 5A is divided and the semiconductor device C is formed into chips, and then the solder layer A is heated and melted using the above-described solder bonding apparatus. A jig 19 may be used.

The jig 19 has substantially the same shape as the circular semiconductor wafer W, and has a concave portion 19a on which a chip-shaped semiconductor device D is mounted on the upper surface thereof. In order to quickly raise and lower the temperature of the solder layer A on the semiconductor device D, it is preferable that the jig 19 is formed of a thin, tough and highly thermally conductive material. Examples of such a material include an inorganic material such as quartz and a metal material such as aluminum nitride. In order to increase and decrease the temperature of the jig 19, the thickness of the quartz jig 19 under the concave portion 19a should be set to 0.5.
mm or less, and the thickness under the concave portion 19a of the jig 19 made of aluminum nitride is preferably 1.0 mm or less.

Incidentally, the processing magazine 2 described above is not limited to the structure shown in FIG.
As shown in the figure, a plurality of net shelves 2 are placed in a cubic frame 2d.
e may be adopted. The vertical pitch between the net shelves 2e is large enough to secure a gap of 5 mm or more between the wafers with the wafers placed on the net shelf 2e. The space between the net shelves 2e also functions as a formic acid introduction space.

According to the processing magazine 2 having such a structure, the restriction on the size of the object to be heated placed therein is reduced, and the versatility is expanded. Moreover, since heat is transmitted to the object to be heated through the eyes of the net shelf 2e, the uniformity of heating to the object to be heated is not impaired. Such a structure may be adopted for the loader 11 and the unloader 12. Further, the formic acid supply mechanism 7 includes the nozzle 6 having the spray holes 6a as shown in FIG. 3, but is not limited to this.

For example, as shown in FIG. 13A, a sprayer having a structure in which formic acid and an inert gas are mixed and mist is formed near the spray hole may be arranged in the heating and melting chamber 3. The sprayer 22 shown in FIG. 13A has a main body 22a having a gas mixing space 22c connected to the spray hole 22b, a formic acid introduction pipe 22d and an inert gas introduction pipe 22e connected to the gas mixing space 22c. . The spray hole 22b of the sprayer 22 is provided with a throttle-type injection valve 22f. The pressure of the inert gas introduced from the inert gas introduction pipe 22e increases the pressure of the gas mixing space 22c. As shown in FIG.
2f is extruded to open the spray hole 22b, and the formic acid introduced from the formic acid introduction pipe 22d is atomized to form the spray hole 2b.
2b to the processing magazine 2.

When the introduction of the inert gas into the gas mixing space 22c is stopped, the injection valve 22f is retracted to close the spray hole 22b, and the discharge of formic acid from the spray hole 22b is stopped. In this case, the spray hole 2 by the injection valve 22f
Since 2b is closed, dripping from the spray hole 22b is prevented. Note that the injection valve 22f may be moved forward and backward by operation of an external force instead of the gas pressure.

As the formic acid supply mechanism, a sprayer 23 having an ultrasonic vibrator as shown in FIG. 14 may be employed. The sprayer 23 shown in FIG. 14 has a main body 23a having a gas mixing space 23c connected to the spray hole 23b, and a formic acid introduction pipe 23d and an inert gas introduction pipe 23e connected to the gas mixing space 23c. The gas mixing space 23
An ultrasonic vibrator 23f is attached to c, and formic acid and an inert gas are mixed on the ultrasonic vibrator 23f to form a mist of ultrasonic formic acid, and the mist is directed to the processing magazine 2 from the spray holes 23b. Release. Ultrasonic transducer 2
3f is driven at the time of mist supply, and controls supply and stop of the formic acid-containing gas by not driving at other times.

In place of the shutters 8 and 9 at the entrance 39 and the exit 3b of the heating and melting chamber 3, a nozzle 25 for discharging an air curtain of nitrogen (inert gas) may be provided. An air curtain may coexist. This makes it possible to reliably prevent formic acid from leaking out of the heating and melting chamber 3. Further, in a state where a wafer or the like is accommodated in the processing magazine 2, an inert gas may be introduced from the nozzle 25 or the inert gas purge nozzle 4a to make the inside of the heating and melting chamber 3 an inert gas atmosphere. (Supplementary Note 1) A magazine for accommodating a plurality of substrates having a solder layer at intervals, a carry-in port for storing the magazine and carrying the substrate into the magazine, and a carry-out port for carrying the substrate out of the magazine. A heating chamber, a first air shielding mechanism and a second air shielding mechanism installed at each of the carry-in port and the carry-out port for shielding the heating chamber from outside air, and confining the magazine in the heating chamber. A solder bonding apparatus comprising: a heater disposed so as to be capable of supplying the formic acid to the heating area; and an exhaust mechanism for discharging the formic acid out of the heating chamber. (Supplementary note 2) The soldering apparatus according to supplementary note 1, further comprising a cooling gas introduction mechanism for introducing a cooling gas into the heater from outside. (Supplementary note 3) The soldering apparatus according to supplementary note 2, wherein the cooling gas is an inert gas. (Supplementary Note 4) The soldering apparatus according to any one of Supplementary Notes 1 to 3, wherein the first and second air shielding mechanisms are at least one of a shutter and an air curtain. (Supplementary Note 5) The solder bonding apparatus according to Supplementary Note 4, wherein the air curtain is an inert gas shower. (Supplementary Note 6) The formic acid supply mechanism has an introduction portion for introducing a mixed mist of formic acid and an inert gas.
6. The soldering apparatus according to any one of claims 1 to 5, wherein (Supplementary note 7) The soldering apparatus according to any one of supplementary notes 1 to 5, wherein the formic acid supply mechanism includes an ultrasonic vibration element for converting formic acid into a mist. (Supplementary note 8) The solder joining apparatus according to Supplementary note 1, 6, or 7, wherein the formic acid supply mechanism has a formic acid introduction part of a solution having a formic acid concentration of 76 vol% or less. (Supplementary note 9) The soldering apparatus according to any one of supplementary notes 1 to 8, wherein the exhaust mechanism has a function of depressurizing the inside of the heater while the magazine is confined by the heater. (Supplementary note 10) The soldering apparatus according to any one of supplementary notes 1 to 19, further comprising a formic acid decomposition mechanism or a formic acid recovery mechanism connected to an exhaust part of the exhaust mechanism. (Supplementary Note 11) The solder joining apparatus according to Supplementary Note 10, wherein the formic acid recovery mechanism includes a heating unit that includes a bath in which a solution for passing exhaust gas discharged from the exhaust mechanism is passed. (Supplementary Note 12) Supplementary note 1 characterized in that a ventilation portion having a plurality of holes through which the exhaust gas passes is provided in the bathtub.
2. The solder bonding apparatus according to 1. (Supplementary note 13) The solder joining apparatus according to supplementary note 12, wherein the solution is water or alcohol. (Supplementary note 14) The solder jointing apparatus according to Supplementary note 10, wherein the formic acid decomposition mechanism has a heating unit that heats the exhaust gas discharged from the exhaust mechanism to 400 ° C or higher. (Supplementary Note 15) The magazine according to any one of Supplementary Notes 1 to 14, wherein the magazine has a support surface for supporting the wafer-shaped base and a formic acid introduction space through which the formic acid passes. The soldering apparatus according to the above description. (Supplementary Note 16) The magazine according to any one of Supplementary Notes 1 to 14, wherein the magazine has a mesh-like support surface that supports the wafer-like base, and a formic acid introduction space into which the formic acid is introduced. A soldering apparatus according to any one of the above. (Supplementary Note 17) The supplementary note 1, 15 or supplementary note, wherein the base is a chip-shaped semiconductor device and is supported by a support, and the support is supported by a plurality of pieces at intervals in the magazine. 17. The soldering apparatus according to item 16. (Supplementary note 18) The soldering apparatus according to supplementary note 17, wherein the support has a concave portion for positioning the semiconductor device and is made of an inorganic material or a metal material. (Supplementary Note 19) Supplementary notes 1 to 18 characterized by having a transport mechanism for moving the magazine in the heating chamber.
The soldering apparatus according to any one of the above. (Supplementary note 20) The soldering apparatus according to any one of supplementary notes 1 to 19, wherein the base is any one of an electronic component, a circuit board, a semiconductor wafer, and a semiconductor chip. (Supplementary note 21) The soldering apparatus according to any one of supplementary notes 1 to 20, further comprising an inert gas introduction mechanism for introducing an inert gas into the heating chamber. (Supplementary Note 22) A step of placing a plurality of substrates having a metal pattern to which a solder layer is attached in a magazine at intervals, a step of covering the magazine with formic acid supplied by a heater in a heating area, and Heating the solder layer and joining the solder layer to the metal pattern,
A step of cooling the solder layer, the metal pattern and the substrate by introducing a cooling gas into the heater and discharging the formic acid in the heater to the outside, and a step of removing the heater from around the magazine; Carrying out the substrate from the magazine. (Supplementary note 23) The solder joining method according to Supplementary note 21, further comprising a step of collecting the formic acid discharged from the inside of the heater by a formic acid collecting mechanism. (Supplementary note 24) The soldering method according to supplementary note 21, further comprising a step of decomposing the formic acid discharged from the heater by a formic acid decomposition mechanism. (Supplementary Note 25) Supplementary note 2 further comprising a step of depressurizing the inside of the heater with the magazine covered.
2. The solder joining method according to 1.

[0049]

As described above, according to the present invention, there is provided a magazine for accommodating a plurality of substrates having a metal pattern to which a solder layer is attached at intervals, and a heater arranged so as to confine the magazine. As a result, the solders on a plurality of substrates can be respectively simultaneously bonded, and the throughput can be improved as compared with the conventional case.

Further, after the solder layer is heated and melted by the heater, the heater is removed from the periphery of the magazine, so that the temperature of the solder layer can be easily lowered and the time from heating to cooling can be shortened. it can. Further, since a structure in which the cooling gas introduction mechanism is attached to the heater is adopted, the cooling can be performed more rapidly by the cooling gas immediately after the heating of the solder layer is completed, and the solder cooling time can be shortened.

When formic acid is supplied to the solder layer, two fluids of formic acid and gas are mixed to suppress the excessive supply of formic acid, or the formic acid is mist-formed by ultrasonic waves. Supply can be suppressed. In addition, since the magazine is contained only in the heating chamber, it is possible to prevent the contaminants in the air from adhering to the magazine and prevent contamination of the substrate during heating.

[Brief description of the drawings]

FIG. 1 is a top view showing a solder bonding apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II of FIG. 1;

FIG. 3 is a perspective view showing a part of a formic acid supply nozzle used in the solder bonding apparatus according to the embodiment of the present invention.

FIG. 4 is a perspective view showing a processing magazine used for the soldering apparatus according to the embodiment of the present invention.

FIGS. 5A and 5B are a perspective view and a side view showing a semiconductor wafer on which solder to be joined by the solder joining apparatus according to the embodiment of the present invention is formed.

6 (a) and 6 (b) are cross-sectional views showing a part of the semiconductor device shown in FIG. 5 (b).

FIG. 7A is a cross-sectional view showing a formic acid recovery mechanism used in the soldering apparatus according to the embodiment of the present invention;
(b) is a sectional view showing a plate incorporated in the formic acid recovery mechanism.

FIGS. 8A to 8C are explanatory views (part 1) of the operation of the soldering apparatus according to the embodiment of the present invention.

FIGS. 9A to 9C are explanatory views (part 2) of the operation of the soldering apparatus according to the embodiment of the present invention.

FIGS. 10A to 10C are explanatory views (part 3) of the operation of the soldering apparatus according to the embodiment of the present invention.

FIGS. 11A and 11B are perspective views showing a jig for mounting a plurality of chip-shaped semiconductor devices on which solder to be joined by a solder joining apparatus according to an embodiment of the present invention is formed. It is a side view.

FIG. 12 is a perspective view showing another processing magazine used for the soldering apparatus according to the embodiment of the present invention.

FIGS. 13 (a) and 13 (b) are cross-sectional views showing another formic acid supply mechanism used in the soldering apparatus according to the embodiment of the present invention.

FIG. 14 is a sectional view showing still another formic acid supply mechanism used in the soldering apparatus according to the embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Magazine mounting table, 2 ... Processing magazine, 3 ... Heat melting chamber, 4 ... Heater, 4a ... Inert gas purge nozzle, 5 ...
Drive mechanism, 5a: support shaft, 6: formic acid spray nozzle,
7 ... formic acid supply mechanism, 8, 9 ... shutter, 10 ... magazine moving mechanism, 11 ... loader, 12 ... unloader, 13,
14 pusher, 15 shutter, 16 exhaust device, 17 formic acid recovery mechanism, 18 sirocco fan, 19
... Jigs, 22, 23 ... Sprayers.

────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI H05K 3/34 507 H05K 3/34 507J 507K 507L // B23K 101: 40 B23K 101: 40 (56) References JP-A-8- 107271 (JP, A) JP-A-3-164040 (JP, A) JP-A-62-124073 (JP, A) JP-A-2001-244618 (JP, A) JP-A-11-233934 (JP, A) JP-A-11-114667 (JP, A) JP-A-6-63733 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B23K 1/00-3/00 B23K 31/02 H05K 3/34

Claims (10)

(57) [Claims] A magazine for accommodating a plurality of substrates having a solder layer at intervals, a loading port for storing the magazine and loading the substrate into the magazine, and a loading opening for unloading the substrate from the magazine. A heating chamber having: a first air shielding mechanism and a second air shielding mechanism installed at each of the carry-in port and the carry-out port to shield the heating chamber from outside air; and the magazine in the heating chamber. A solder bonding apparatus comprising: a heater disposed so as to be confined; a formic acid supply mechanism for supplying formic acid to the heating area; and an exhaust mechanism for discharging the formic acid out of the heating chamber. 2. The solder joining apparatus according to claim 1, further comprising a cooling gas introduction mechanism for introducing a cooling gas from outside into the heater. 3. The solder joining apparatus according to claim 1, wherein the first and second air shielding mechanisms are at least one of a shutter and an air curtain. 4. The solder joining apparatus according to claim 1, wherein said formic acid supply mechanism has an introduction portion for introducing a mixed mist of formic acid and an inert gas. 5. The solder joining apparatus according to claim 1, wherein the formic acid supply mechanism has an ultrasonic vibration element for converting formic acid into a mist. 6. The solder joint according to claim 1, wherein the exhaust mechanism has a function of depressurizing the inside of the heater while the magazine is confined by the heater. apparatus. 7. The soldering apparatus according to claim 1, further comprising a formic acid decomposition mechanism or a formic acid recovery mechanism connected to an exhaust part of the exhaust mechanism. 8. The magazine according to claim 1, wherein the magazine has a support surface for supporting the wafer-shaped substrate, and a formic acid introduction space through which the formic acid passes. The soldering apparatus according to any one of the above. 9. The magazine according to claim 1, wherein said magazine has a mesh-like support surface for supporting said wafer-like substrate, and a formic acid introduction space for introducing said formic acid therein. 8. The soldering apparatus according to any one of items 7. 10. A step of placing a plurality of substrates having a metal pattern to which a solder layer is attached in a magazine at intervals, a step of covering the magazine with formic acid supplied thereto with a heater in a heating area, Heating the solder layer to join the solder layer to the metal pattern; and introducing a cooling gas into the heater to cool the solder layer, the metal pattern and the base, and to mix the formic acid in the heater. A step of discharging the heater to the outside, a step of removing the heater from around the magazine, and a step of carrying out the substrate from the magazine.