JP2000068331A - Electronic component bonding apparatus and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an electronic component bonding apparatus and method which can stabilize bonding quality. SOLUTION: In this method for eutectically bonding a chip 8 onto a substrate 6 heated in an inert-gas atmosphere, nitrogen gas is supplied from a nitrogen gas blow-out port provided in the heat block 22 to surroundings of the substrate 6, while the substrate 6 is heated by a heat block 22 carrying the substrate 6. Then the heated nitrogen gas is supplied from a plurality of holes in a periphery of an opening 23a made in a cover member 23, provided to cover the heat block 22 and corresponding to an elevating position of a bonding tool 32 to the surroundings of the chip 8. Thereby a stable low-oxygen atmosphere can be provided to the surroundings of the chip 8 to be bonded, thus making a bonding quality stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component bonding apparatus and method for bonding electronic components to a substrate.

[0002]

2. Description of the Related Art As a method for mounting an electronic component on a substrate,
Methods of performing bonding while heating the substrate, such as eutectic bonding and solder bonding, are known. In this method, an electrode of an electronic component is bonded to a substrate by heating the substrate to a predetermined temperature such as a eutectic temperature or a melting point of solder. In this joining process, it is common practice to supply an inert gas such as nitrogen gas around the joint to reduce the oxygen concentration in order to prevent oxidation of the metal surface of the joint and obtain good joining quality. I have. Conventionally, as a method for supplying nitrogen gas, a method has been known in which a nitrogen gas supply hole is provided in a heat block on which a substrate is placed and heated, and nitrogen is supplied around the substrate. In order to prevent the nitrogen gas from diffusing from the periphery of the substrate, a cover member is often provided over the substrate. The cover member has an opening through which a bonding tool for holding an electronic component moves up and down with respect to the substrate. However, since this opening also serves as an inert gas outflow hole, it is necessary to take measures to prevent nitrogen gas from flowing out from this opening. For this reason, conventionally, a method has been used in which a nozzle of a hot gun is provided outside the opening and nitrogen gas ejected from the nozzle is blown in through the opening to reduce the outflow of nitrogen gas.

[0003]

However, when nitrogen gas is blown, oxygen in the surrounding atmosphere is also blown into the inside of the cover member from the opening at the same time, so that oxygen is supplied around the electronic components. Was. For this reason, it is difficult to form a stable low-oxygen atmosphere around the joint, and as a result, there is a problem that the bonding quality is not stable.

It is an object of the present invention to provide an electronic component bonding apparatus and a bonding method capable of stabilizing bonding quality.

[0005]

According to a first aspect of the present invention, there is provided an electronic component bonding apparatus for bonding an electronic component to a substrate heated in an inert gas atmosphere. A heat block to be placed and heated; a first inert gas supply unit provided in the heat block to supply an inert gas around the placed substrate; and an electronic component mounted on the substrate and bonded. A bonding tool, a cover member disposed over the heat block, the cover member having an opening corresponding to an elevation position of the bonding tool, and a plurality of holes provided around the opening of the cover member. A second inert gas supply unit for supplying an inert gas to the periphery of the electronic component from the above, and heating the inert gas supplied from the second inert gas supply unit And a scan heating means.

According to a second aspect of the present invention, there is provided a bonding apparatus for an electronic component, wherein the heat block on which the substrate is mounted is horizontally moved relative to the bonding tool and the cover member. A moving means for moving is provided.

According to a third aspect of the present invention, there is provided a method for bonding an electronic component to a substrate heated in an inert gas atmosphere, wherein the electronic component is bonded by a heat block on which the substrate is placed. While heating the substrate, the first
An inert gas supply unit for supplying an inert gas around the substrate, and a plurality of peripheral parts around an opening provided on a cover member disposed over the heat block so as to correspond to an elevation position of a bonding tool. The inert gas heated by the gas heating means is supplied to the periphery of the electronic component from the hole by the second inert gas supply unit.

According to the invention described in each claim, an inert gas is supplied by a first inert gas supply section provided on a heat block on which a substrate is placed and heated, and the heat block is covered by the first inert gas supply section. The inert gas heated by the gas heating means is supplied to the second inert gas supply unit from a plurality of holes around the opening provided in the cover member corresponding to the elevation position of the bonding tool. Thus, a stable low oxygen atmosphere can be formed around the electronic component to be bonded.

[0009]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a perspective view of an electronic component bonding apparatus according to an embodiment of the present invention. FIG. 2 is a perspective view of a bonding portion of the electronic component bonding apparatus.
3A is a side view of a bonding portion of the electronic component bonding apparatus, FIG. 3B is a front view of a bonding portion of the electronic component bonding device, FIG. 4 is a cross-sectional view of the bonding heat block, and FIG. (A), (b) is a perspective view of the nitrogen gas nozzle unit of the bonding device of the same electronic component.

First, the structure of the bonding apparatus will be described with reference to FIG. The bonding apparatus includes a substrate supply unit 1, transport paths 2A and 2B, a bonding unit 3, a chip supply unit 4,
It comprises a position correction unit 5. The substrates 6 are stacked and stored in the stocker 11 of the substrate supply unit 1. The substrate 6 is sucked by the nozzle 13 of the transfer head 12 and transferred from the stocker 11 onto the transport path 2A. The transport path 2 </ b> A includes a plurality of heat blocks 15, and transports the substrate 6 placed on the upstream side to the bonding unit 3 by sequentially feeding the substrate 6 with the transport claws 16. During this transfer, the substrate 6 is heated by the heat block 15 and rises to the eutectic bonding temperature.

The bonding section 3 is provided with a heat block 2 on a movable table including an X table 20 and a Y table 21.
2 is mounted. The heat block 22 is covered with a cover 23, and a nitrogen gas nozzle unit 24 for supplying nitrogen gas as an inert gas is mounted on the cover 23.

A chip supply section 4 is provided beside the bonding section 3. The chip supply unit 4 supplies a chip 8 which is an electronic component of the wafer 7, and the chip 8
It is picked up by one nozzle 32 and temporarily placed in the position correction unit 5. The position corrector 5 corrects the position of the chip 8 by pressing the position regulating claw 34 against the chip 8 temporarily placed on the table 33.

The chip 8 whose position has been corrected here is
It is picked up by the bonding tool 36 of the bonding head 35, mounted on the substrate 6 mounted on the heat block 22, and subjected to eutectic bonding. A gold preform supply unit 39 is provided on the other side of the bonding unit 3, and the gold tape 40 derived from the supply unit 39 is cut into gold preforms 40 a according to the size of the chip 8. You. The cut gold preform 40a is supplied to the nozzle 3 of the preform head 37.
Then, the wafer is vacuum-sucked by 8 and transferred to the substrate 6. The bonding head 35 mounts and bonds the chip 8 on the gold preform 40a.

Next, the bonding section 3 will be described with reference to FIGS. In FIG. 2, the X table 20
A heat block 22 is mounted on a Y table 21 stacked on the table. A notch 22a is provided on the upper surface of the heat block 22, and the substrate 6 conveyed on the heat block 15 on the upstream side is pushed by the conveying claw 16 so that the substrate 6 is placed on the notch 22a of the heat block 22. Is sent and placed.

The X table 20 has a heat block 22
A cover member 23 that covers the upper surface of the cover is fixed. The cover member 23 is provided with an opening 23a for mounting the chip 8 and an opening 23b for chip recognition. The chip 8 held by the bonding tool 36 is mounted on the substrate 6 on the heat block 22 via the opening 23a. The substrate 6 is recognized by the camera 41 via the opening 23b. Openings 23a, 23b and bonding tool 3
The positional relationship between the camera 6 and the camera 41 is fixed, and the X table 20 and the Y table 21 move the heat block 22 on which the substrate 6 is placed relative to the bonding tool 36 and the cover member 23 in the horizontal direction. It is a means of transportation.

Around the opening 23a, a nitrogen gas nozzle unit 24 as a second inert gas supply means is mounted. As shown in FIG. 5A, a large number of nitrogen gas blowing holes 24a are provided on the lower surface of the nitrogen gas nozzle unit 24. A nitrogen gas supplied from a gas supply source (not shown) is heated by a heater 47 as gas heating means. The heating temperature is detected by a temperature sensor 46, and the nitrogen gas whose temperature is controlled by a temperature control unit (not shown)
It is blown out from a.

The nitrogen gas nozzle unit 24 is shown in FIG.
As shown in (2), it is mounted in alignment with the opening 23a. The cover member 23 is provided with a nitrogen gas supply hole 23c corresponding to the position of the blowout hole 24a. Therefore,
By driving the nitrogen gas nozzle unit 24, a nitrogen gas heated to a predetermined temperature is supplied around the opening 23a, and a low oxygen atmosphere is formed around the chip 8 to be bonded. The arrangement of the nitrogen gas supply holes 23c is not limited to the linear arrangement shown in FIG.
It may be arranged so as to surround the periphery of a. By employing such an arrangement, a more stable low oxygen atmosphere can be formed concentrated around the chip 8. Further, by mounting the nitrogen gas unit 24 on the cover member 23, an effect of increasing the rigidity of the cover member 23 is obtained, and the bending of the cover member 23 that occurs during heating can be effectively prevented.

As described above, the opening 23 of the cover member 23
Since the positional relationship between the bonding tools 36 and the camera 41 is fixed, the openings 23a, 23b,
3b can be limited to the minimum required size. In the conventional bonding apparatus, since the cover member is fixed to the Y table, when the X table is driven, the cover member moves relative to the bonding tool. For this reason, the opening for bonding must be formed into a long hole shape that covers the relative movement, and it is necessary to provide an opening with a large opening area. This is one of the factors that makes it impossible to realize a stable low oxygen atmosphere in the conventional bonding apparatus. Compared with the structure of the cover member in such a conventional bonding apparatus, according to the cover member 23 of the present embodiment, the bonding opening 23a and the recognition opening 23b are reduced to a minimum opening area. Thus, a stable low oxygen atmosphere can be realized by minimizing the outflow of nitrogen gas.

Openings 23a,
A shutter 42 for opening and closing the opening 23a is provided.
b can be opened only when necessary. A shutter 44 is also provided on the side surface of the heat block 22. By driving the cylinder 45, the end of the notch 22a can be opened and closed. As described above, by providing the shutter at the opening, the hermeticity of the space where the substrate 6 is placed above the heat block 22 on which the substrate 6 is placed is improved, and a more stable low oxygen atmosphere is formed. be able to.

Next, the structure of the heat block 22 will be described with reference to FIG. In FIG. 4, on the upper surface of the cut portion 22a of the heat block 22, a large number of nitrogen blowing holes 22b as a first inert gas supply portion are provided. The nitrogen outlet 22b is connected to a nitrogen gas supply source (not shown) through the inner hole 22c. A heater 50 is embedded inside the heat block 22. By driving the heater 50, the substrate 6 placed on the cutout 22a is heated and the nitrogen gas blown out from the nitrogen blowout hole 22b is removed. Heat.

The heat block 22 is mounted on the Y table 21 via a heat insulating material 51 and a porous member 52. A space 52a is provided in the porous member 52,
By supplying cooling air into the space 52a via the pipe 55, air is sent into the fine holes of the porous member 52, absorbing heat from the heater 50 and conducting the heat downward. To prevent The porous member 52 is a bolt 53
The heat block 22 is fixed to the porous member 52 by bolts 53. Accordingly, there is no good heat conductor that directly conducts the heat from the heat block 22 to the Y table 21, and an excellent heat insulating effect can be obtained in combination with the cooling effect of the porous member 52.

This electronic component bonding apparatus is configured as described above, and the bonding operation will be described below. In FIG. 1, the substrate 6 of the stocker 11 is placed on the uppermost stream heat block 15 of the transport path 2A by the transfer head 12. While the substrate 6 is sequentially conveyed on the downstream heat block 15, the substrate 6 is heated and its temperature rises. And the heat block 2 of the bonding part 3
The substrate 6 fed onto 2 is heated to the eutectic temperature of the chip 8. The preform head 3 is
7, the gold preform 40a is mounted, and the chip 8 whose position has been corrected by the position correction unit 5 is mounted on the gold preform 40a, and eutectic bonding is performed.

At this time, nitrogen gas is blown out around the entire substrate 6 from nitrogen blowing holes 22 b provided in the heat block 22, and the chip 8 to be bonded is blown through nitrogen gas supply holes 23 c provided in the cover member 23. , The surroundings of the bonding site can be maintained in a stable low oxygen atmosphere. The bonding space on the upper surface of the heat block 22 is such that the openings 23a and 23b of the cover member 23 are
As a result, the end of the cut portion 22a can be opened and closed by the shutter 44, so that these opening portions are opened only when necessary, so that the heat block 2
2. The nitrogen gas supplied into the space above 2 can be effectively prevented from flowing out, and a stable low oxygen atmosphere is maintained during bonding, thereby suppressing the oxidation of the metal surface of the joint. And good bonding quality can be obtained.

The substrate 6 after bonding is sent out to the transport path 2B, and is sequentially transported on the heat block 15 to the downstream side, so that the temperature is gradually lowered and cooled. The cooled substrate 6 is sent into the stocker 17 by the carry-in claw 16 to complete the bonding process.

[0025]

According to the present invention, a cover member for supplying an inert gas by a first inert gas supply unit provided in a first heat block for mounting and heating a substrate and covering the substrate. By supplying the inert gas heated by the second inert gas supply unit provided in the above, a stable low oxygen atmosphere can be formed around the electronic component to be bonded. Therefore, oxidation of the metal surface of the bonding portion can be prevented in the bonding process, and stable bonding quality can be ensured.

[Brief description of the drawings]

FIG. 1 is a perspective view of an electronic component bonding apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view of a bonding unit of the electronic component bonding apparatus according to one embodiment of the present invention;

3A is a side view of a bonding unit of the electronic component bonding apparatus according to one embodiment of the present invention; FIG. 3B is a front view of a bonding unit of the electronic component bonding apparatus according to one embodiment of the present invention;

FIG. 4 is a sectional view of a bonding heat block according to an embodiment of the present invention.

5A is a perspective view of a nitrogen gas nozzle unit of an electronic component bonding apparatus according to an embodiment of the present invention. FIG. 5B is a perspective view of a nitrogen gas nozzle unit of an electronic component bonding apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate supply part 2A, 2B conveyance path 3 Bonding part 4 Chip supply part 6 Substrate 8 Chip 20 X table 21 Y table 22 Heat block 22b Nitrogen blowing hole 23 Cover member 23a Opening 24 Nitrogen gas nozzle unit 47 Heater

Claims (3)

[Claims] 1. An electronic component bonding apparatus for bonding an electronic component to a substrate heated in an inert gas atmosphere, comprising: a heat block for mounting and heating the substrate; A first inert gas supply unit for supplying an inert gas around the mounted substrate, a bonding tool for mounting an electronic component on the substrate for bonding, and the bonding tool disposed over the heat block. A cover member provided with an opening corresponding to the elevating position of the electronic component, and a second supplying an inert gas to the periphery of the electronic component through a plurality of holes provided around the opening of the cover member. An electronic component bonding apparatus comprising: an inert gas supply unit; and gas heating means for heating an inert gas supplied from the second inert gas supply unit. Location. 2. A bonding apparatus for electronic parts according to claim 1, further comprising moving means for relatively moving a heat block on which said substrate is mounted on said bonding tool and said cover member in a horizontal direction. apparatus. 3. A method of bonding an electronic component to a substrate heated in an inert gas atmosphere, the method comprising bonding the electronic component to the substrate while heating the substrate with the heat block on which the substrate is mounted. An inert gas is supplied to the periphery of the substrate by the first inert gas supply unit provided, and an opening is provided in a cover member disposed over the heat block so as to correspond to an elevation position of the bonding tool. The inert gas heated by the gas heating means is passed through the plurality of holes around the
And supplying the electronic component around the electronic component by an inert gas supply unit.