JP2002064116A - Flux coater on solder ball on bga semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flux coater on solder balls on a BGA semiconductor device by which races formed on the flux surface by solder balls dropped on a flux coating disk can be eliminated. SOLUTION: With respect to the flux coater on semiconductor balls on a BGA semiconductor device, a ball stopping scraper 4 is provided in the rearward position of a flattening scraper 3 provided on a flux coating disk 1 in the rotating direction of the disk 1 and flux (a) is supplied between the scrapers 3 and 4 of the flux coating disk 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for applying flux to solder balls in a BGA type semiconductor device.

[0002]

2. Description of the Related Art Conventionally, a ball transfer device is usually used for mounting a solder ball in a BGA type semiconductor device.

In such a ball transfer device, a large number of solder balls are vacuum-adsorbed at predetermined intervals in order to transfer solder balls to through holes formed on the back surface of a frame of a BGA type semiconductor device. After the flux is applied to the outer hemisphere, it is transferred to the through hole of the frame of the BGA type semiconductor device such that the flux applied surface opposes the through hole.

As described above, when a flux is applied to the outer hemisphere of the solder ball vacuum-adsorbed to the transfer device, a flux-coated disk is used. That is, the flux surface is leveled by a scraper while supplying and applying the flux layer on a disk, and the solder balls adsorbed and held by a ball transfer device are partially immersed in the flattened flux layer to perform soldering. Apply flux to the outer hemisphere of the ball.

[0005]

However, when the solder balls held by vacuum suction on the solder ball transfer device are applied by contacting the flux layer on the flux application disk, the solder balls are adsorbed by the ball transfer device. There was a possibility that the film would be peeled off from the holding portion and fall to remain on the flux layer on the disk.

As described above, when the solder balls fall on the flux-applied disc and remain on the flux layer, the applicator disc is rotated in this state while supplying the flux, and the leveling work is performed by the leveling scraper. The solder ball locked on the flattening scraper forms an annular groove with the solder ball on the surface of the flux, and the flux is not sufficiently applied even if the solder ball comes into contact with this groove. As a result, the solder balls are not sufficiently welded to the frame of the die-shaped semiconductor device, and defective products lacking the solder balls are manufactured.

[0007]

According to the present invention, a ball stopper scraper is provided at the rear of the leveling scraper provided on the flux-applying disk in the direction of rotation of the disk, and the flux is applied between the scrapers on the flux-applying disk. And a flux application device for solder balls in a BGA type semiconductor device, characterized in that the flux application device is provided.

[0008] The ball stopper scraper is also characterized in that it can receive the solder ball and discharge it to the outside of the flux-coated disk.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, two scrapers are arranged on a rotatable flux-applied disk in a radial direction from the center of the disk.

That is, a leveling scraper is disposed in front of the disk in the rotation direction, and a ball stopper scraper is disposed behind the disk in the rotation direction of the disk while maintaining a constant interval (angle).

The space between the scrapers is used as a flux supply space.

The surface of the flux coating layer on the disk is leveled by a leveling scraper while rotating the flux-coated disk thus configured, and the solder ball transfer device is moved above the flux-rotating disk to transfer the solder balls. The solder ball sucked and held by the head of the apparatus is immersed in the surface of the leveled flux layer, and the flux is applied to the outer hemisphere of the ball.

In such a flux applying step, when the solder balls are separated from the head of the solder ball transfer device and fall on the surface of the flux layer, the solder ball transfer device is rotated with the rotation of the disk by the leveling operation. Once separated and dropped, the solder balls are first received by the ball stopper scraper at the rear in the disk rotation direction, and the disk is further fed while supplying flux to the flux supply space between the flattening scraper and the disk rotation direction front. When it is rotated, it is received by the ball stopper scraper, and the groove formed by the solder ball is sufficiently filled back by the leveling of the supplied flux by the leveling scraper and disappears, and the rotating direction of the leveling scraper is rotated forward. Are not formed at all by the falling solder balls.

Therefore, the flux can be sufficiently applied to the solder balls adsorbed on the head of the solder ball transfer device by the flux surface having no grooves, and the solder balls can be completely reflowed to the frame.

Further, since the falling solder balls received by the ball stopper scraper can be automatically ejected out of the disk with the rotation of the disk, the step of removing the falling solder balls from the flux-coated disk can be omitted. Things.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a plan view showing a flux coating apparatus A of the present invention, FIG. 2 is a cross-sectional view taken along line II of FIG. FIG.
FIG. 2 is a sectional view taken along the line II-II in FIG. 1.

In FIG. 1, reference numeral 1 denotes a flux-coated disk, and the disk 1 has a rotating shaft 2 on a lower surface of a central portion.
It is linked to a motor (not shown) and is configured to rotate counterclockwise through the rotating shaft 2, that is, to rotate leftward.

At the twelve o'clock position above the disk 1, a leveling scraper 3 for leveling the flux a laminated on the surface of the disk 1 is provided, and the disk rotating direction of the leveling scraper 3 is provided. Behind the ball stop scraper 4
Is disposed, and the ball stopper scraper 4 regulates the height from the disk 1 so that the solder ball b dropped on the disk can be received.

Moreover, the leveling scraper 3 and the ball stopper scraper 4 are disposed in a state of extending radially from the center of the disk 1, and the angles are set so that the angle becomes about 90 degrees or less. keeping.

On the upper surface of the flux-applied disc 1, the space between the flat scraper 3 and the ball stopper scraper 4 within about 90 degrees is defined as a flux supply space s. A flux supply nozzle 5 for supplying the flux is provided, from which the flux is periodically supplied to the flux supply space s for each rotation of the flux application disk 1.

That is, each time the operation of applying the flux to the solder balls b adsorbed on the head d of the solder ball transfer device c is completed on the flux application disk, the flux application disk 1 rotates and this rotation operation is performed. Each time, the flux is supplied onto the same disk, and the upper surface of the flux is leveled by the leveling scraper 3.

The supply of the flux is most efficiently performed during the rotation of the disk 1, but may be performed immediately before the rotation.

The leveling scraper 3 functions to level the surface of the flux a supplied to the disk 1 so as to form a flux layer having a uniform thickness from the disk surface. A straight rectangular plate can be formed by extending from the portion to the peripheral edge of the disk, and the lower edge portion of the flux-applied disk 1 that contacts the surface of the flux layer is formed as a thin blade.

The ball stopper scraper 4 has a function of receiving the solder ball b dropped onto the flux layer from the head d of the solder ball transfer device c. , And a straight rectangular plate extending from the edge of the disk to the periphery of the disk, and at least an interval shorter than the diameter of the solder ball b is provided between the disk and the surface of the disk.

Each of the scrapers 3 and 4 is constructed as described above. Therefore, when applying the flux a to the solder balls b of the solder ball transfer device c, the solder ball transfer device c is placed on the same disk 1. After the outer surface of the solder ball b is immersed in the flattened flux layer on the disk so that the outer surface of the solder ball b is immersed, the solder ball transfer device c is moved to the outer surface of the solder ball b. The solder balls b on which the flux has been applied are transferred to through holes formed in a large number of frames of the BGA type semiconductor device and are transferred to a reflow process. When the solder ball b separates from the head d of the mounting device c and falls on the surface of the flux layer on the disk, the disk 1
Rotate while placing.

Then, the dropped solder ball b is received by the ball stopper scraper 4 and stopped there. Therefore, a streak groove m is formed on the disk by the solder ball b on the flux surface. The new groove supplied to the flux supply space s and the underside thereof are repaired and leveled by the leveling scraper 3 by the leveling scraper 3, and the space between the ball stopper scraper 4 and the leveling scraper 3 is removed. The space on the disk is a flat flux surface without the streaks m.

Further, the ball stopper scraper 4 can be configured not only to receive the solder ball b but also to be able to discharge the solder ball b out of the flux-applied disk 1.

That is, when the ball stopper scraper 4 receives the dropped solder ball b together with the rotation of the disk, the rear side of the ball stopper scraper 4 automatically guides the received solder ball b out of the disk. The ball receiving surface is a convex curved surface 4-1, and the tangent P of the curved surface at the center of the disk of the ball stopper scraper 4 is at least 90 degrees or more with the flat scraper 3 so that the convex curved surface 4 is maintained. As a result, as shown in FIG. 6, the solder balls falling along with the left rotation of the flux-applied disk 1 lie along the convex curved surface 4-1 of the ball stopper scraper 4, as shown in FIG. To move out of the disk, and is eventually discharged out of the disk.

As another embodiment of the ball stopper scraper 4, as shown in FIGS. 4 and 5, a ball is pushed out from the center of the disk toward the peripheral edge along the rear surface of the ball stopper scraper 4. The sliding piece 6 is slidably mounted, and the sliding piece 6 moves with the rotation of the disk to push the dropped solder ball b out of the disk and discharge it.

An interlocking mechanism between the rotation of the flux-applying disk 1 and the sliding piece 6 is provided with a male screw 7 along the ball stopper scraper 4, and the female screw hole of the sliding piece 6 is provided in the male screw 7. And the sliding piece 6 moves with the rotation of the male screw 7 to discharge the solder ball b out of the disk.

[0031]

According to the first aspect of the present invention, since the ball stopper scraper is disposed behind the leveling scraper in the rotating direction of the disk, even if the disk is rotated while supplying the flux, the dropped solder ball is fixed to the ball stopper. Since the flux is received by the scraper and the flux surface is leveled by the leveling scraper in front of the scraper, no streaks are formed by the falling ball on the flux surface. Accordingly, the flux can be sufficiently applied to all the solder balls when performing the flux applying operation to the balls, and there is an effect of preventing the occurrence of defective products in which the solder balls are missing.

According to the second aspect of the present invention, since the ball stopper scraper receives the solder ball and can discharge it to the outside of the flux-applied disk, there is no need to remove the solder ball that has dropped and remained on the flux surface. Therefore, there is an effect that the ball can be automatically discharged to the outside of the disk by the ball stopper scraper, which has an effect of contributing to labor saving of the work of applying the flux.

[Brief description of the drawings]

FIG. 1 is a plan view showing an apparatus for applying a flux to solder balls in a BGA type semiconductor device of the present invention.

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

FIG. 3 is an end view taken along the line II-II of FIG. 2;

FIG. 4 is a plan view of another embodiment.

FIG. 5 is a sectional view taken along line III-III in FIG. 4;

FIG. 6 is a plan view of another embodiment.

[Explanation of symbols]

 Reference Signs List A flux application device a flux b solder ball c solder ball transfer device d head 1 flux application disk 2 rotating shaft 3 leveling scraper 4 ball stopper scraper 5 flux supply nozzle

Claims (2)

[Claims] A ball-stopping scraper (4) is disposed behind a leveling scraper (3) provided on a flux-applied disc (1) in the rotational direction of the disc, and a flux-applied disc is provided.
A flux coating device for solder balls in a BGA type semiconductor device, characterized in that the flux (a) is supplied between the scrapers (3) and (4) of (1). 2. The BGA type semiconductor device according to claim 1, wherein the ball stopper scraper (4) is configured to receive the solder ball and discharge the solder ball to the outside of the flux application disk (1). Flux coating device.