JP3245581B2 - Pellet adsorption mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pellet mounting mechanism having a nozzle structure for use in vacuum mounting and mounting (die bonding) pellets in a pellet mounting apparatus used in a semiconductor device manufacturing process.

[0002]

2. Description of the Related Art Conventionally, a pellet mounting apparatus used in a semiconductor device manufacturing process, for example, when mounting a pellet on a lead frame, vacuum-adsorbs the pellet by a suction mechanism having a nozzle structure, and presses the pellet against the lead frame while adsorbing. After mounting, the inside of the nozzle is released to the atmosphere to release the vacuum, and the nozzle is separated from the pellet to complete the pellet mounting.

A conventional pellet suction mechanism attached to such a pellet mounting apparatus will be described with reference to FIG. 3A and 3B are diagrams showing the structure of a conventional pellet adsorption mechanism, wherein FIG. 3A shows a pellet adsorption operation, and FIG. 3B shows a pellet mounting operation.

A conventional pellet suction mechanism as shown in FIG. 3 is attached to a part of a pellet mounting device (not shown), and the whole suction mechanism can move in the X-Y directions, and the pellet suction mechanism is moved. It has a function of performing an operation and a pellet mounting operation.

As shown in FIG. 3, a cylindrical nozzle holder 11 is fitted to a slide type bearing 12 fixed to the pellet mounting device side, and the nozzle holder 1 is mounted.
Numeral 1 can be slid in the vertical direction (Z direction). The nozzle holder 11 is attached to the suction block 13, and the nozzle holder 11 and the suction block 13 move integrally.

In the center of the nozzle holder 11, a central axial suction hole 16 is formed.
Is connected to a vacuum pipe 15 through a vacuum suction hole 15a in the suction block 13 via a radial suction hole 16a.
The nozzle 18 serving as a pellet suction portion at the tip of the nozzle holder 11 is made of rubber, and serves as a cushioning material to prevent breakage of the pellet.

[0007] Further, the bearing 12 and the suction block 1
3, a mounting load spring 14 is stretched between them. The position where the distance a is minimized (regulated by a stopper or the like) is determined by the nozzle holder 11.
Becomes the lowest position, and becomes the reference position of the mount load applied to the pellet by the mount load spring 14 at the time of mounting.

When the pellet mounting is performed using the pellet adsorption mechanism having such a structure, first, FIG.
As shown in (a), the whole wafer is moved by moving the entire pellet suction mechanism onto the pellets 17 individually bonded on a sheet (not shown), and the pellets 17 are pushed up and brought into contact with the nozzles 18. . At the same time, vacuum piping 15
When the air is evacuated, the pellets 17 are separated from the sheet and adsorbed by the nozzles 18.

Next, as shown in FIG. 3B, the entire pellet suction mechanism is moved onto the island, which is the mounting position of the lead frame 19, while the pellet 17 is being suctioned, and the entire pellet suction mechanism is lowered. Pellets 1
7 comes into contact with the lead frame 19 and the nozzle holder 11
Even if the lowering of the bearing stops, the mounting load spring 14 extends because the bearing 12 continues to lower, and the lowering is stopped when a predetermined mounting load is applied to the pellet 17.

At the same time, the valve 20 is switched from vacuum to atmosphere to switch the suction hole 1 in the central axis direction of the nozzle holder 11.
The vacuum in 6 is released and the atmosphere is released at the same time. In this way, the pellet mounting is completed by pressing the pellet onto the island via the adhesive.

An example of such a pellet adsorption mechanism for opening the inside of the nozzle to the atmosphere is disclosed in, for example, JP-A-63-29539.
As disclosed in Japanese Patent Application Laid-Open Publication No. H10-209, there has been proposed a mechanism in which a switching valve is provided in the middle of a vacuum pipe to switch between vacuum in a nozzle and the atmosphere.

[0012]

When the pellet mounting on the island of the lead frame is completed by using the above-mentioned conventional pellet suction mechanism, the valve 20 provided at the end of the vacuum pipe 15 is operated, and The vacuum in the axial suction hole 16 is released to open to the atmosphere, and at the same time, the entire pellet suction mechanism rises, the nozzle 18 separates from the pellet 17, and the pellet 17
9 is fixed.

However, since the path from the nozzle 18 to the valve 20 is long, in a high-speed mounting operation, the release of the vacuum to the atmosphere cannot be made in time, and the nozzle holder 11 rises without the pellet 17 being separated from the nozzle 18.
A so-called pellet take-back phenomenon occurs in which the mounted pellet is peeled off from the adhesive.

An object of the present invention is to solve the problem of the pellet carry-out phenomenon and to provide a pellet suction mechanism capable of performing a high-speed mounting operation capable of easily releasing to the atmosphere.

[0015]

According to the present invention, there is provided a pellet suction mechanism having a nozzle for sucking pellets at a lower end thereof and a nozzle holder slidable up and down via a bearing. In the pellet suction mechanism to be performed, the nozzle holder has a suction block integrally attached to the bearing and the nozzle holder is slidably fitted, and the suction block is provided with a vacuum suction hole that opens on a sliding surface with the nozzle holder. Further, the nozzle holder has a radial suction hole connected to the central axial suction hole, and an open groove is provided on the outer peripheral surface of the nozzle holder above the radial suction hole, and the central axial suction is provided in the open groove. The open-to-atmosphere hole leading to the hole is radially opened.

At the time of the pellet suction operation, the vacuum suction operation of the pellets is performed by matching the positions of the radial suction holes of the nozzle holder and the vacuum suction holes of the suction block. It stays out and shuts off the air from flowing into the open air hole.

Further, at the time of the pellet mounting operation,
Slide the suction block down with respect to the nozzle holder, shift the position of the radial suction hole of the nozzle holder and the vacuum suction hole of the suction block to shut off the vacuum, and at the same time, open the groove out of the suction block to open to the atmosphere. Atmosphere flows into the hole, and the suction hole in the central axis direction of the nozzle holder is opened to the atmosphere to separate the pellet from the nozzle.

In addition to the vacuum suction holes, the suction block is provided with an air inlet hole that opens on the slide surface with the nozzle holder.

In the pellet suction operation, the position of the radial suction hole of the nozzle holder and the position of the vacuum suction hole of the suction block are matched to perform the vacuum suction operation of the pellet. The position of the block is shifted from the air inlet hole to block the inflow of air into the air open hole.

In the above-mentioned pellet mounting operation,
The suction block is slid down with respect to the nozzle holder, and the position of the radial suction hole of the nozzle holder and the position of the vacuum suction hole of the suction block are shifted to shut off the vacuum. Atmosphere flows into the hole, and the suction hole in the central axis direction of the nozzle holder is opened to the atmosphere to separate the pellet from the nozzle.

[0021]

Next, embodiments of the present invention will be described in detail with reference to the drawings. FIGS. 1A and 1B are configuration diagrams showing a first embodiment of a pellet suction mechanism according to the present invention. FIG. 1A illustrates a pellet suction operation, and FIG. 1B illustrates a pellet mounting operation. It is.

First, the configuration of the pellet adsorption mechanism of the present invention will be described with reference to FIG. The pellet adsorption mechanism according to the first embodiment includes a pellet mounting device (not shown).
The whole suction mechanism is capable of moving in the X-Y directions, and has a function of performing a pellet suction operation and a pellet mounting operation.

As shown in FIG. 1, a cylindrical nozzle holder 1 is fitted to a slide type bearing 2 fixed to the pellet mounting device side, and the nozzle holder 1 can slide in the vertical direction (Z direction). It has become.
Further, a suction block 3 is attached to the bearing 2, and the bearing 2 and the suction block 3 have an integral structure. The suction block 3 is provided with a through hole through which the nozzle holder 1 slidably passes.

A central axial suction hole 6 is formed in the center of the nozzle holder 1, and a radial suction hole 6 a connected to the central axial suction hole 6 and a vacuum suction hole 5 a provided in the suction block 3. It is connected to a vacuum pipe 5. The nozzle holder 1 has an open groove 10 formed by cutting a part of the outer periphery of a shaft portion of the nozzle holder 1, and an open air groove 10 a extending radially from the central axial suction hole 6 in the open groove 10. Has been opened.

During periods other than the pellet mounting operation, the open groove 10 is housed in the suction block 3 (the state shown in FIG. 1A), and the air opening hole 10a is closed. The nozzle 8 serving as a pellet suction portion at the tip of the nozzle holder 1 is formed of rubber, and serves as a cushioning material to prevent breakage of the pellet.

Further, a distance b is provided between the suction block 3 and the member 1a mounted on the upper part of the nozzle holder 1.
And the load spring 4 is stretched. The position where the distance b is minimized (regulated by a stopper or the like) is the position where the nozzle holder 1 is at the lowest position, and is the reference position of the mount load applied to the pellet by the mount load spring 4 during mounting.

The case of performing the pellet adsorption and the pellet mounting using the pellet adsorption mechanism of the present invention having such a structure will be described with reference to FIGS. 1 (a) and 1 (b). First, as shown in FIG. 1A, in order to perform a pellet suction operation, the wafer is divided and the entire pellet suction mechanism is moved onto a pellet 7 attached to a sheet (not shown).

Next, when the pellet 7 is pushed up through the sheet to come into contact with the nozzle 8 and at the same time, the vacuum pipe 5 is evacuated, the pellet 7 is separated from the sheet and adsorbed by the nozzle 8. At this time, the positions of the radial suction holes 6a of the nozzle holder 1 and the vacuum suction holes 5a of the suction block 3 match, and the member 1a attached to the upper part of the nozzle holder 11 and the suction block 3 Between
The state of the interval b is maintained.

Next, as shown in FIG. 1B, a pellet mounting operation is performed. First, the entire suction mechanism is moved onto the island, which is the mounting position of the lead frame 9, while the pellet 7 is being suctioned, and the entire suction mechanism is lowered. Even if the pellet 7 comes in contact with the lead frame 9 and the descent of the nozzle holder 1 is stopped, the suction block 3 and the bearing 2 continue to be lowered, so that the mount load spring 4 is extended and drops when a predetermined mount load is applied to the pellet. To stop.

As described above, at the same time when the pellet 7 comes into contact with the lead frame 9, the suction block 3 starts to lower. Then, the opening groove 10 goes out of the suction block 3 and the atmosphere opening hole 10a is also exposed, and the atmosphere flows in. At the same time, the positions of the radial suction holes 6a and the vacuum suction holes 5a are shifted, and the vacuum path is cut off. Therefore, the vacuum in the central axial direction suction hole 6 of the nozzle holder 1 is instantaneously released to the atmosphere, and the pellet 7 is instantaneously separated from the nozzle 8 and is stably supplied onto the lead frame 9.

Next, a second embodiment of the present invention will be described. FIGS. 2A and 2B show a part of a pellet suction mechanism according to the second embodiment. FIG. 2A shows a state during a pellet suction operation, and FIG. 2B shows a state during a pellet mounting operation. , Respectively.

In the first embodiment, at the time of the pellet mounting operation, the opening to the atmosphere is performed by the opening groove 10 formed in the nozzle holder 1 coming out of the suction block 3 by the lowering of the suction block 3. In the present embodiment, the opening groove 10 of the nozzle holder 1 is prevented from coming off from the suction block 3 even when the suction block 3 is lowered, and the suction block 3 has an air inlet hole 10b in addition to the vacuum suction hole 5a. , A plurality of nozzles are provided radially around the nozzle holder 1.

First, as shown in FIG. 2A, at the time of the pellet suction operation, the radial suction holes 6a of the nozzle holder 1 are used.
Since the position of the suction block 3 matches the position of the vacuum suction hole 5a, vacuum suction of the pellet is performed. Next, as shown in FIG. 2B, at the time of the pellet mounting operation, the suction block 3 is moved down, the positions of the radial suction holes 6a and the vacuum suction holes 5a are shifted, and the vacuum is cut off. When the position of the open groove 10 and the position of the air inlet hole 10b of the suction block 3 coincide with each other, the air flows into the central axial direction suction hole 6, and the adsorption of the pellet is released.

According to the present embodiment, since the air opening hole 10a in the open groove 10 does not come out of the suction block 3, dust and foreign matter are not sucked into the air opening hole 10a when the air is opened to the atmosphere. There is no worry about clogging.

[0035]

According to the pellet suction mechanism of the present invention, the addition of the air release hole and the open groove to the shaft portion of the pellet suction nozzle holder allows the nozzle holder to slide while mounting the pellet after suction. The vacuum is shut off, air flows in from the air release hole and the open groove, and the suction hole in the nozzle holder is released to the atmosphere.
Since the shutoff of the vacuum and the opening of the atmosphere, which were conventionally performed by switching the valve far away, are now performed near the pellet, the separation of the pellet from the nozzle can be performed instantaneously.

As described above, the provision of the air opening hole and the opening groove in the nozzle holder allows the pellet separation operation to be performed while responding to the high-speed mounting operation and the weight reduction of the pellet suction mechanism. Can be secured.

[Brief description of the drawings]

FIGS. 1A and 1B show a first embodiment of the present invention. FIG. 1A shows a pellet adsorption operation, and FIG. 1B shows a pellet mounting operation.

FIGS. 2A and 2B show a second embodiment of the present invention. FIG. 2A shows a pellet adsorption operation, and FIG. 2B shows a pellet mounting operation.

FIG. 3 is a diagram showing a conventional pellet adsorption mechanism, and FIG.
Shows a pellet adsorption operation, and FIG. 8B shows a pellet mounting operation.

[Explanation of symbols]

 1,11 Nozzle holder 1a Member 2,12 Bearing 3,13 Suction block 4,14 Mounting load spring 5,15 Vacuum piping 5a, 15a Vacuum suction hole 6,16 Central axis direction suction hole 6a, 16a Radial direction suction hole 7, 17 Pellet 8,18 Nozzle 9,19 Lead frame 10 Open groove 10a Open air hole 10b Open air hole 20 Valve

Claims (6)

(57) [Claims] 1. A pellet suction mechanism for performing a pellet suction operation and a pellet mounting operation, comprising a nozzle holder having a nozzle for suctioning a pellet at a lower end thereof and being slidable vertically through a bearing, and being integrally attached to the bearing. A suction block in which the nozzle holder is slidably fitted, the suction block is provided with a vacuum suction hole that opens on a slide surface with the nozzle holder, and the nozzle holder is provided with a suction hole in the central axial direction. An opening groove is provided on the outer peripheral surface of the nozzle holder above the radial suction hole, and an air opening hole connected to the central axial suction hole is radially opened in the opening groove. A pellet adsorption mechanism. 2. At the time of the pellet suction operation, the vacuum suction operation of the pellets is performed by matching the positions of the radial suction holes of the nozzle holder and the vacuum suction holes of the suction block. 2. The pellet adsorption mechanism according to claim 1, wherein the mechanism stops and blocks the inflow of the atmosphere into the atmosphere opening hole. 3. At the time of the pellet mounting operation, the suction block is slid down with respect to the nozzle holder, the position of the radial suction hole of the nozzle holder is shifted from the position of the vacuum suction hole of the suction block, and the vacuum is cut off. 2. The pellet adsorption according to claim 1, wherein the groove exits from the adsorption block, air flows into the air release hole, and the central axial suction hole of the nozzle holder is opened to the atmosphere to separate the pellet from the nozzle. mechanism. 4. The pellet suction mechanism according to claim 1, wherein the suction block is provided with an air inlet hole opened on a sliding surface with the nozzle holder, in addition to the vacuum suction hole. 5. At the time of the pellet suction operation, the position of the radial suction hole of the nozzle holder and the position of the vacuum suction hole of the suction block are matched to perform the vacuum suction operation of the pellet. 5. The pellet adsorption mechanism according to claim 4, wherein a position of the block is shifted from an air inlet hole to block an inflow of air into the air open hole. 6. At the time of the pellet mounting operation, the suction block is slid down with respect to the nozzle holder, the position of the radial suction hole of the nozzle holder is shifted from the position of the vacuum suction hole of the suction block, and the vacuum is cut off. 5. The pellet adsorption according to claim 4, wherein the groove is coincident with the air inflow hole, the air flows into the air opening hole, and the pellet is separated from the nozzle by opening the central axial suction hole of the nozzle holder to the atmosphere. mechanism.