KR100854438B1 - Flux dotting device of ball mounting system for manufacturing semiconductor packages - Google Patents

Abstract

A flux depositing apparatus of a ball mounting system for fabricating a semiconductor package is provided to deposit flux on a precise position of a bonding pad by depositing flux on a strip several times and by re-arranging the position of the strip with respect to the center of movable blocks in each deposition process. A base block(11) is installed on the main body of a ball mounting system, capable of transferring in an arbitrary direction. A plurality of movable blocks(14,15) are installed under the base block, capable of transferring vertically and independently. A plurality of flux pins(16) for depositing flux on each bonding pad(P) of a strip(S) are formed under each movable block. An elevation driving unit vertically elevates each movable block with respect to the base block. A buffer unit(19a) can reduce the impact applied to the movable block when each movable block is elevated.

Description

Flux Dotting Device of Ball Mounting System for Manufacturing Semiconductor Packages

1 is a sectional view showing the main parts of a conventional flux coating apparatus.

FIG. 2 is a cross-sectional view illustrating main parts of a flux applied to a strip by the flux applicator of FIG. 1; FIG.

Figure 3 is a plan view showing a state in which the flux coating device according to an embodiment of the present invention is applied to the ball mounting system

4 to 6 are main cross-sectional views showing the structure and operation of the flux coating device of FIG.

Figure 7 is a plan view showing another embodiment of a state in which the flux coating device of the present invention is applied to a ball mounting system

Figure 8 is a plan view showing another embodiment of a state in which the flux coating device of the present invention is applied to a ball mounting system

Explanation of symbols on the main parts of the drawings

10: flux coating device 11: base block

12: horizontal moving block 13: Z-axis motor

14: first movable block 15: second movable block

16 flux pin 17 first pneumatic cylinder

18: 2nd pneumatic cylinder 19: guide shaft

19a: buffer means C: carrier

S: Strip P: Bonding Pad

Rx: X-axis robot Ry: Y-axis robot

V: Vision Camera

The present invention relates to a device for attaching a ball to a strip in the manufacture of a semiconductor package, and more particularly, flux in each ball mounting position (hereinafter referred to as a 'bond pad') of the strip in the manufacturing process of a BGA type semiconductor package. When applying, the present invention relates to a flux applicator of a ball mounting system for manufacturing a semiconductor package such that the flux can be applied at the correct position of the strip bonding pad.

In the method of manufacturing a semiconductor package, a BGA type semiconductor package forms an external circuit through a ball mounting process of attaching solder balls to a predetermined position of a strip, that is, a bonding pad. This ball mounting process is performed automatically in a ball mounting system.

The ball mounting system continuously applies flux to the bonding pads on each semiconductor chip of the strip taken out from the cassette and continuously attaches the ball to each of the bonding pads to which the flux is applied.

In more detail, the ball mounting system removes the strip from the cassette and mounts it on the carrier, and then returns the carrier to the flux application position, where the bonding pad on each semiconductor chip of the strip is used with the flux application device. Apply flux to the The ball mounting process is then carried out by conveying the carrier to the ball attachment position, supplying the ball to be attached to the strip through the ball supply section, and then attaching the balls on the ball supply section to the respective bonding pads of the strip with a ball mount head to vacuum suction. do.

However, if the deformation occurs in the strip prior to the ball mounting process, as described above, in the process of attaching the ball to the strip in the ball mounting system, an offset between the position of the bonding pad of the strip and the flux pin of the flux applicator is offset. Since the flux is not applied to the correct position of the bonding pads occurs.

That is, the strip is subjected to a molding process before the ball mounting process, in which the strip may shrink or expand or deform, such as bending, by heat. In this case, the position of each bonding pad of the deformed strip is different from the position of each bonding pad of the strip in the normal state, so that the position of each flux pin of the flux applicator and the position of the bonding pad do not exactly match, so that the flux is bonded There is a problem that the coating is not applied to the correct position of the pad.

1 and 2 of the accompanying drawings shows a process in which the flux is applied to the strip by a conventional flux applicator, the conventional flux applicator is movable in the Y-axis and Z-axis direction on the top of the ball mounting system A base block (1) to be installed, a Z axis motor (2) for elevating the base block (1) in the Z-axis direction, a pin holder block (3) fixed to a lower end of the base block (1), and The pin holder block 3 includes a plurality of flux pins 4 installed to correspond to the respective bonding pads P of the strip S.

The conventional flux coating apparatus configured as described above operates as follows.

When the strip (S) is seated on the upper surface of the carrier (C), the carrier (C) is moved to the flux application position along the X-axis linear motion device. At this time, the position of the center point of the strip is detected by the vision camera (not shown) while the carrier C is moving. At the flux application position the carrier C is aligned at a position where the center point of the strip S coincides with the center point of the pinholder block 3 of the flux applicator.

On the other hand, while the carrier C conveys the strip S to the flux application position, the flux applicator embeds the flux F on the flux pins 4 at the flux supply unit (not shown), and then Y axis. Move in the direction to align on the carrier (C).

As described above, when the position between the carrier C and the flux applicator is aligned, the Z-axis motor 2 is operated as shown in FIG. 2 so that the base block 1 is lowered by a predetermined distance toward the carrier C. The flux F of the flux pin 4 is applied to the bonding pad P of the strip S.

However, as described above, when the deformation occurs in the strip S and the position of the bonding pad P is shifted to a certain degree from the normal position, that is, when an offset occurs in the position of the bonding pad P, FIG. 2. As shown in FIG. 5, when the base block 1 and the pin holder block 3 are lowered and the flux pin 4 is connected to the strip S, the flux F is not applied to the bonding pad P correctly. Occurs.

The present invention is to solve the above problems, an object of the present invention to provide a flux coating apparatus of the ball mounting system for manufacturing a semiconductor package that can perform the flux coating operation accurately and quickly even if the deformation occurs in the strip. .

The present invention for achieving the above object, in the flux coating device for applying the flux for ball attachment to the bonding pads of the plurality of semiconductor package region formed in the strip, in any direction on the top of the body of the ball mounting system A base block movably installed; A plurality of movable blocks which are installed to be movable up and down independently of the base block, and having a plurality of flux pins formed thereon to apply flux to each bonding pad of the strip; It provides a flux coating device of the ball mounting system for semiconductor package manufacturing, characterized in that it comprises a lifting drive unit for lifting and lowering each movable block with respect to the base block.

According to the present invention, the flux is applied to the strip in several times in the flux application position and the position of the strip is rearranged with respect to the center of the movable blocks in each application process so that deformation occurs in the strip so that the bonding pad position is in the normal position. Even if it is shifted to some extent, the flux can be applied to the exact position of the bonding pad.

In addition, in the process of applying the flux to the strip in multiple times, the flux may be continuously applied at the flux application position without returning to the flux supply unit before completion of the flux application for one strip. Therefore, the flux application operation can be made quickly, and the productivity can be improved.

Hereinafter, with reference to the accompanying drawings a preferred embodiment of the flux coating device of the ball mounting system for manufacturing a semiconductor package according to the present invention will be described in detail.

First, as shown in Figure 3, the main body of the ball mounting system is configured such that the carrier C on which the strip is seated moves in the X-axis direction by the X-axis robot Rx. In addition, a vision camera V is installed on the movement path of the carrier C to detect the posture and the position of the strip S by photographing the strip S mounted on the carrier C. The flux coating device 10 is configured to move horizontally in the Y-axis direction by the Y-axis robot Ry on the main body of the ball mounting system.

Referring to FIG. 4, the flux applicator 10 is separately installed on the base block 11 and the lower end of the base block 11 so as to be movable in the horizontal and vertical directions by the Y-axis robot Ry. The first movable block 14 and the second movable block 15 and the first and second movable blocks 14 and 15, which are installed to be movable up and down, and the first and second movable blocks 14 and 15 are respectively lifted up and down by a predetermined stroke. A second pneumatic cylinder (17, 18) and a plurality of flux pins 16 are installed in the lower portion of the first and second movable blocks (14, 15) to correspond to each bonding pad of the strip.

The base block 11 is a linear movement device such as a ball screw (not shown) and a Z-axis motor 13 in a horizontal moving block 12 installed to move horizontally in the Y-axis direction by the Y-axis robot Ry. It moves up and down (in the Z-axis direction). Accordingly, the base block 11 moves horizontally in the Y-axis direction from the top of the ball mounting system by the movement of the horizontal moving block 12, and moves in the Z-axis direction by the operation of the Z-axis motor 13. do.

The flux pins 16 of the first movable block 14 apply flux to the bonding pads P of the semiconductor packages corresponding to half of the strip S, and the flux pins 16 of the second movable block 15. Are applied to the bonding pads P of the semiconductor packages corresponding to the other half of the strip S.

In addition, the first movable block 14 and the second movable block 15 are inserted through the guide hole 11a formed in the base block 11, and the first and second with respect to the base block 11. Guide shafts 19 for guiding the lifting motions of the movable blocks 14 and 15 are installed. And, the upper end of each of the guide shaft 19, the first and second movable blocks (14, 15) is provided with a cushioning means (19a) for absorbing the shock when moving downward relative to the base block (11). Therefore, when the first and second movable blocks 14 and 15 are moved up and down by the operation of the first and second pneumatic cylinders 17 and 18, the first and the second movable blocks 14 and 15 are guide shafts. The lifting position is guided by the 19 and the guide hole 11a, and the lowering means absorbs the shock while hitting the upper surface of the base block 11 during the lowering.

In order to mitigate the impact between the flux pin 16 and the bonding pad P of the strip S when the flux fins 16 apply flux on the strip S, the flux pins 16 are It is preferable to flow slightly elastically up and down with respect to the first and second movable blocks 14 and 15. To this end, the flux pins 16 are installed in units of one or a plurality of semiconductor packages on a lower surface of a plurality of pin mount blocks (not shown) installed to elastically move with respect to the first and second movable blocks 14 and 15. do.

The first and second pneumatic cylinders 17 and 18 are installed in the base block 11, and the piston rods thereof are connected to the center of the first and second movable blocks 14 and 15, and are applied by the applied pneumatic pressure. The first and second movable blocks 14 and 15 are moved up and down by a predetermined stroke.

The flux coating device of the present invention configured as described above operates as follows.

As shown in FIG. 4, when the strip S is seated on the upper surface of the carrier C, the carrier C is moved to the flux application position by the X-axis robot Rx. While the carrier C moves to the flux application position, the vision camera V (see FIG. 3) photographs the strip S seated on the carrier C, and the position of the quarter point of the strip S Detects the 3/4 point position.

While the carrier C moves to the flux application position as described above, the flux applicator 10 has a flux applied to the end of the flux pin 16 of the first and second movable blocks 14 and 15 at the flux supply portion. Next, it moves in the Y-axis direction and arranges on the flux application | coating position.

At this time, as shown in Fig. 5, the first movable block 14 of the flux applicator is aligned so that its center coincides with a quarter point of the strip S. The alignment between the first movable block 14 of the flux applicator 14 and the strip S is dependent on the Y-axis movement of the base block 11 of the flux applicator and the X-axis and θ-direction motion of the carrier C. Is made by

As described above, when alignment between the first movable block 14 and the strip S is made, pneumatic pressure is applied to the first pneumatic cylinder 17 to move the first movable block 14 downward by a predetermined distance. do. Accordingly, the ends of the flux pins 16 of the first movable block 14 are lowered than the ends of the flux pins 6 of the second movable block 15.

When the power is applied to the Z-axis motor 13 in this state, the base block 11 is lowered at a constant speed and distance, and the flux that is floating on the lower end of the flux pin 16 of the first movable block 14 It is transferred to the bonding pads P and applied.

Subsequently, the first movable block 14 is raised again to return to the initial position by the operation of the first pneumatic cylinder 17, and the Z-axis motor 13 is operated in the opposite manner to that described above, so that the base block 11 is predetermined. Rise to height

And, as shown in Figure 6, the carrier (C) is moved by a predetermined distance in the X-axis direction so that the center of the second movable block 15 is aligned with the position of the 3/4 point of the strip (S).

Subsequently, while pneumatic pressure is applied to the second pneumatic cylinder 18, the second movable block 15 descends downward by a predetermined distance, and the flux pins 16 of the second movable block 15 are moved to the first movable block 14. Will be moved below the flux pins (16).

Then, when the power is applied to the Z-axis motor 13, the base block 11 is lowered at a constant speed and distance, and the flux that is floating on the lower end of the flux pin 16 of the second movable block 15 strips. Flux F is apply | coated, being connected to the bonding pad P of the other half part of (S).

As such, when flux is applied to the bonding pads P of the other half of the strip S, the second movable block 15 is raised by the operation of the second pneumatic cylinder 18 to return to the initial position, and Z The axial motor 13 operates in reverse to that described above, so that the base block 11 is raised back to its original position. The flux applicator 10 then moves to the flux supply position for the next flux application operation. At the same time, the carrier C moves to the ball mount position, and the ball is attached to each bonding pad P at this position.

The flux applicator 10 repeatedly applies the flux to each bonding pad P of the strip S while repeatedly performing the above-described process.

According to the present invention, when the flux applicator subtracts the flux at the flux supply and then applies the flux to the strip S at the flux application position, the flux S to the flux pin 16 of the first movable block 14. After applying flux to half of, the strip S is rearranged with respect to the second movable block 15 and the second movable block 15 is lowered immediately at the position so that the flux on the remaining half of the strip S Since F) is applied, the flux coating operation is more accurate than before, and the flux coating operation can be performed within a short time.

That is, when the flux is applied to the strip S by dividing twice into the first and second movable blocks 14 and 15 having a half size than the conventional movable block as in the present invention, the strip S Since only half of the flux pin-to-bond pad needs to be absorbed, the amount of error is reduced by half, thus improving the accuracy of the flux application.

On the other hand, the flux coating apparatus of the above-described embodiment is configured to move the movable blocks 14, 15 up and down independently in the base block 11, alternatively three or more movable in the base block 11 The blocks may be constructed to apply flux at least three times per strip.

In addition, in the above-described embodiment, the flux coating device includes only one base block 11, and is configured to perform flux coating only for one strip. Alternatively, the flux coating device may be a dual type or the like. It can also be configured as a multi-type.

For example, as shown in FIG. 7, the base block 11 is configured in plural (two in this embodiment), and the first and second movable block (not shown) pairs are configured for each base block 11. In addition, a plurality of strips S (two in this embodiment) may also be mounted on the carrier C, so that the flux coating operation may be simultaneously performed on the two strips S at a time. Of course, even in this case, the first and second movable blocks of each base block 11 are divided into two flux coating operations for each strip S.

In addition, as shown in Fig. 8, a plurality of (two in this embodiment) Y-axis robots Ry1 and Ry2 and two Y-axis robots Ry1 and Ry2 in the Y-axis direction on the top of the ball mounting system. A plurality of independently applied flux coating apparatuses 10 (two in this embodiment) are provided, and a plurality of (two in this embodiment) X-axis robots Rx1 and Rx2 in the X-axis direction, respectively, It is possible to configure a plurality of carriers C (two in this embodiment) that move independently along the X-axis robots Rx1 and Rx2. A vision camera Y-axis robot Ry is placed on the upper side of the X-axis robot Rx to photograph the strips S of two carriers C moving along the two X-axis robots Rx. The vision camera V is installed in the Y-axis robot Ry for the vision camera.

When the two flux applicators 10 and the carrier C are configured to move independently as described above, one flux applicator 10 performs the flux application to one carrier C while the other Since the flux coating device 10 of the flux coating operation can be performed independently for the other carrier (C) can further increase the efficiency and speed of the flux coating operation.

Further, in the above-described embodiment of the flux applying apparatus, the first and second pneumatic cylinders 17 and 18 are configured as the elevating driving unit for elevating the first and second movable blocks 14 and 15, but in addition to the pneumatic cylinder The lifting drive unit may be configured using a well-known linear motion device such as a rack and pinion gear, a ball screw, or a plurality of pulleys and a belt.

Although the present invention exerts an optimum effect when applied to a flux applicator for applying flux to a strip, the present invention is equally applicable to a ball mount head for performing ball mounting on a strip in a ball mounting system in addition to the flux applicator. Similar applications could be made. That is, a plurality of movable blocks for adsorbing and fixing the ball to the ball mounting head are formed in a plurality, and the movable blocks are configured to move up and down independently of each other, thereby attaching the ball to each bonding pad of the strip. You may be able to do it in parts.

As described above, according to the present invention, the flux is applied to the strip in several times in the flux application position, and in each application process, the position of the strip is rearranged with respect to the center of the movable blocks, so that deformation of the strip occurs and the bonding pad position is increased. The flux can be applied to the exact position of the bonding pad, even if it deviates to some extent from the normal position.

In addition, in the process of applying the flux to the strip in multiple times, the flux may be continuously applied at the flux application position without returning to the flux supply unit before completion of the flux application operation for one strip. Therefore, the flux coating operation can be made quickly, there is an advantage that can improve the productivity.

Claims (6)

A flux coating device for applying flux for ball attachment to bonding pads of a plurality of semiconductor package regions formed in a strip, A base block movably installed in an arbitrary direction on an upper portion of the main body of the ball mounting system; A plurality of movable blocks which are installed to be movable up and down independently of the base block, and having a plurality of flux pins formed thereon to apply flux to each bonding pad of the strip; And a lift drive unit configured to lift and move each of the plurality of movable blocks up and down relative to the base block. The method of claim 1, wherein the plurality of movable blocks comprises a first movable block having flux pins for applying flux to the bonding pads formed on the half of the strip, and the flux on the bonding pads formed on the other half of the strip. Flux coating apparatus of the ball mounting system for manufacturing a semiconductor package, characterized in that consisting of two of the second movable block having flux pins to apply. The method of claim 2, wherein the first movable block is lowered in a state in which the center of the first movable block and a quarter point of the strip are aligned to apply the flux to the bonding pad of the half portion of the strip, the second movable block The movable block is lowered with the center of the second movable block and 3/4 points of the strip aligned to apply flux to the bonding pads of the other half of the strip. Flux applicator. The pneumatic cylinder according to claim 1, wherein the elevating driving unit is fixed to the base block and has a piston rod coupled to each of the plurality of movable blocks to individually lift and move each of the plurality of movable blocks to a predetermined stroke. Wow; Flux coating device comprising a guide member for guiding the lifting motion of each of the plurality of movable blocks with respect to the base block. The flux coating apparatus according to claim 1, further comprising buffering means for reducing a shock applied to the movable block during the lifting movement of each of the plurality of movable blocks. The semiconductor package according to claim 4, further comprising buffering means installed on the upper end of each of the guide members to reduce the impact applied to the movable block while hitting the upper surface of the base block during the lifting movement of each movable block. Flux applicator for manufacturing ball mounting systems.

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