JP2002299808A - Method of controlling amount of solder ball and solder ball feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep solder balls in a solder ball tray proper in amount always and to enable a pickup head to always carry out a solder ball suction operation stably. SOLUTION: A solder ball tray 2 is vibrated by a vibration generator 6, solder balls 1 (amount of solder balls is so set as to cover 50% or so of the area of the bottom of the tray 2) residing in the solder ball tray 2 are nearly uniformly scattered on the bottom, the density of solder balls 1 residing in a prescribed region in the solder ball tray 2 is detected in this state by a solder ball sensor 7, the amount of solder balls in the solder ball tray 2 is estimated, and a solder ball replenishing command signal is outputted to a solder ball replenishing mechanism 8 when it is judged that the solder balls are required to be replenished.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solder ball for detecting the amount of solder balls in a solder ball tray for storing solder balls and performing control for maintaining an appropriate amount of solder balls in the solder ball tray. The present invention relates to an amount control method and a solder ball supply device to which the solder ball amount control method is applied.

[0002]

2. Description of the Related Art Conventionally, in order to mount a minute ball-shaped solder on a semiconductor chip, an electrode pad of an inner lead of a film carrier, or another circuit board, an apparatus for supplying the minute solder ball to a mounting portion. It has been known. This type of solder ball supply device performs an operation of picking up a predetermined amount of solder balls each time a pickup operation is performed by a pickup head and transferring the solder balls stored in a solder ball tray to the next process. Repeat. Therefore, it is important that an appropriate amount of solder balls always exist in the solder ball tray.

Therefore, it is necessary to replenish the solder balls in the solder ball tray by some method so that the pickup head can cope with each suction operation of the solder balls in the ball tray. For example, tens of thousands of solder balls are stored in a solder ball tray.
Assuming that 00 solder balls are adsorbed, the same number of solder balls are always held in the solder ball tray if 5000 new solder balls are automatically supplied for each adsorption operation. Will be done.

[0004]

Conventionally, after a solder ball is sucked from a solder ball tray, a number corresponding to the number of the sucked solder balls is replenished to the solder ball tray by various methods. However, the number of solder balls that are reduced by being attracted to the pickup head is not necessarily constant each time because the solder balls may adhere to places other than the solder ball suction holes. Furthermore, the number of solder balls to be replenished at one time is determined by the adhesion of solder balls due to static electricity (cluster).
Can not be counted correctly because For these,
It is impossible to accurately supply the solder balls corresponding to the number reduced by being attracted to the pickup head.

For this reason, when the suction and replenishment of the solder balls are repeated by the conventional method, sooner or later the number of solder balls in the solder ball tray will be out of the proper range.
If the number of solder balls in the solder ball tray is not appropriate, the number of solder balls adsorbed on the pickup head tends to be excessive or insufficient.

In order to solve this problem, an apparatus has been developed for refilling the solder balls when the number of solder balls in the solder ball tray becomes smaller than a specified value (Japanese Patent Laid-Open No. 200/200).
0-191125). This device measures the number of solder balls remaining in the solder ball tray after collecting the balls at one corner of the solder ball tray by tilting the solder ball tray in order to improve the measurement accuracy of the number of solder balls.

[0007] Such a method of tilting the solder ball tray has a serious disadvantage that an extra tilting device is required and an extra step is required. Furthermore, such a device employs a method in which balls accumulated in multiple layers in the solder ball tray are blown off by air from below, so that most of the solder balls supplied into the solder ball tray are removed. Since it is exposed to air for a long time without being adsorbed, there is a disadvantage that oxidation of the solder ball surface is accelerated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and accurately detects the amount of solder balls in a solder ball tray and always makes the amount of solder balls in a solder ball tray an appropriate amount. It is an object of the present invention to provide a solder ball amount control method and a solder ball supply device capable of preventing the solder balls from being oxidized by performing such control and stabilizing the suction of the solder balls by the pickup head. .

[0009]

In order to achieve the above object, a method of controlling the amount of solder balls according to the present invention is to provide a method of controlling the amount of solder balls in a solder ball tray for storing an appropriate amount of solder balls capable of coping with a pickup head suction operation. And controlling the solder ball amount in the solder ball tray by controlling the amount of the solder ball in the solder ball tray. Are spread almost uniformly on the bottom surface in the solder ball tray, and in a state where the solder balls are almost evenly distributed, it is detected whether or not the solder ball needs to be replenished, and the solder ball needs to be replenished. Is detected, the solder balls are replenished.

As described above, by vibrating the solder ball tray, the solder balls existing in the solder ball tray are scattered almost uniformly in the solder ball tray, and the solder balls are replenished to the solder ball tray. Is detected, it is possible to accurately detect whether or not the solder ball needs to be replenished. Then, based on this detection result, if the solder balls need to be replenished, the solder balls are replenished, so that the amount of the solder balls in the solder ball tray can always be kept at an appropriate amount, thereby. In addition, it is possible to prevent the solder balls from being oxidized and to stabilize the suction of the solder balls by the pickup head.

[0011] Further, in a state where the solder balls are almost uniformly scattered in the solder ball tray, the amount of the solder balls occupying 30 to 70% of the area of the bottom surface in the solder ball tray is almost entirely over the bottom surface. It is preferable to make the state scattered uniformly.

As described above, the amount of the solder balls in the solder ball tray is set to an amount occupying approximately 50% of the area of the bottom surface in the solder ball tray. This is because when performing the operation, the solder balls are likely to jump uniformly, and if the amount of the solder balls is larger than that, even if the solder ball tray is vibrated, the solder balls interfere with each other and may overlap,
If the parts are too close, the jumping condition tends to be uneven, and conversely, if the amount of solder balls is smaller than that,
This is because it is easy for the pickup head to be excessively or insufficiently attracted to the solder ball.

The detection of whether or not the solder ball tray needs to be replenished with solder balls is performed by detecting the density of solder balls at a predetermined portion in the solder ball tray and determining whether or not the solder ball tray needs replenishment based on the detected density. It is preferable to determine whether

As described above, by detecting the solder ball density at a predetermined portion in the solder ball tray, it is determined whether or not it is necessary to refill the solder ball into the solder ball tray. And it can be determined accurately.

It is preferable that the position where the solder ball density is detected in the solder ball tray is at least a position near a solder ball replenishing portion in the solder ball tray and a position avoiding a solder ball suction range by the pickup head.

Thus, the density of the solder balls can be detected with higher accuracy. That is, in some cases, the replenished solder balls tend to stay near the solder ball replenishing portion, and the density detected at that portion has low reliability as a value representing the density of the entire solder ball tray. Is affected by the suction operation of the pickup head, and also in this case, the density detected at that portion has low reliability as a value representing the density of the entire solder ball tray.

Further, when replenishing the solder balls to the solder ball tray, the replenishment amount is controlled by time, and the amount of solder which is equal to or slightly smaller than one suction amount by the pickup head for a predetermined time is controlled. A ball refill operation is performed.

As described above, when the replenishment amount is managed by time, an operation program for performing replenishment control and a control mechanism for executing the replenishment control can be simplified. Also,
By setting the replenishing amount to be equal to or slightly smaller than the amount of one suction, even if the solder ball sensor fails, the amount of the solder ball tends to decrease. This does not cause problems such as overflow from the surface or insufficient adsorption.

Further, the solder ball supply device of the present invention comprises a solder ball tray for storing solder balls, a solder ball replenishment mechanism for replenishing the solder balls to the solder ball tray, and a solder ball stored in the solder ball tray. A pickup head for adsorbing a predetermined amount of the ball for each suction operation and transferring the solder ball to the next step; a housing for supporting the solder ball tray so that the solder ball tray can vibrate; and a solder ball tray And a solder ball sensor that outputs a replenishment command signal to the solder ball replenishment mechanism when it is determined that replenishment of the solder balls present in the solder ball tray is necessary. By vibrating the solder ball tray with a vibration generator, the solder balls existing in the solder ball tray are replaced with the solder balls. With the solder balls scattered almost uniformly on the bottom surface in the ray, and with the solder balls scattered almost uniformly, the solder ball sensor detects whether or not it is necessary to replenish the solder balls existing in the solder ball tray. When it is detected that the solder ball needs to be replenished, a replenishment command signal is output to the solder ball replenishment mechanism.

As described above, by vibrating the solder ball tray, the solder balls existing in the solder ball tray are almost uniformly scattered in the solder ball tray. Since it is detected whether or not the replenishment is necessary, it is possible to accurately detect whether or not the replenishment of the solder ball is necessary. Then, based on this detection result, if the solder balls need to be replenished, the solder balls are replenished, so that the amount of the solder balls in the solder ball tray can always be kept at an appropriate amount, thereby. , While preventing oxidation of the solder balls,
It is possible to stabilize the suction of the solder ball by the pickup head.

According to another aspect of the present invention, in addition to the above-described solder ball supply device, a solder ball sensor is provided based on density detection means for measuring the density of solder balls at a predetermined portion in a solder ball tray, and the measured density data. And arithmetic operation control means for determining whether or not solder ball replenishment is necessary.

As described above, the density measuring means detects the solder ball density at a predetermined portion in the solder ball tray, and the arithmetic and control means determines whether or not solder ball replenishment is necessary based on the density. The necessity of replenishment of the solder balls can be easily and accurately determined with a simple configuration.

According to still another aspect of the present invention, in addition to the solder ball supply device of the above-mentioned invention, the density detecting means is a proximity sensor.

As described above, since the proximity sensor is used as the means for detecting the density of the solder balls, it is possible to arrange the proximity sensor on the bottom surface of the solder ball tray. Further, it is easy to make the sensor surface of the proximity sensor flush with the bottom surface of the solder ball tray.

Further, the detection position of the solder ball density in the solder ball tray of the solder ball sensor should be at least a position near the solder ball replenishing portion in the solder ball tray and a position avoiding the solder ball suction range by the pickup head. Is preferred.

Thus, the density of the solder balls can be detected with higher accuracy. That is, in the vicinity of the solder ball replenishing portion, the replenished solder ball tends to stay, and the density detected in that portion is low in reliability as a value representing the density of the entire solder ball tray, and the pickup range of the pickup head is This is because the pickup head is affected by the suction operation, and also in this case, the density detected at that portion has low reliability as a value representing the density of the entire solder ball tray.

In another invention, in addition to the solder ball supply device of each of the above-mentioned inventions, when the solder ball replenishing mechanism replenishes the solder balls to the solder ball tray, the replenishment amount is managed by time, and The replenishing operation of the solder ball is performed for a predetermined time and slightly less than the amount of one suction by the pickup head.

As described above, when the replenishment amount is managed by time, an operation program for performing replenishment control and a control mechanism for executing the replenishment control can be simplified. Also,
By making the replenishment amount smaller than the amount of one adsorption,
Even if the solder ball sensor breaks down, the amount of solder balls will decrease, so there will be no problems such as excessive accumulation of solder balls, overflowing the solder ball tray, or insufficient suction. Become.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a solder ball supply apparatus and a solder ball amount control method according to the present invention will be described below with reference to FIGS.

FIG. 1 is a block diagram for explaining an embodiment of a solder ball supply device according to the present invention. In FIG. 1, only parts necessary for explaining the present invention are shown. The solder ball supply device according to the embodiment of the present invention is, roughly,
A solder ball tray (hereinafter referred to as a ball tray) 2 made of stainless steel for storing the solder ball 1 on its bottom surface 2a;
A ball tray support housing 4 that supports an end of the ball tray 2 with an elastic member 3 such as a leaf spring; and a movable member that is movable on the ball tray 2 in the horizontal and vertical directions. , A pickup head 5 having a mechanism for vertically moving with respect to the bottom surface 2a of the ball tray 2 and adsorbing the solder balls 1 stored in the ball tray 2, and a ball tray support housing 4
A vibration generator 6 installed in the ball tray 2 to apply a vibration force to the ball tray 2, a solder ball sensor 7 provided on the bottom surface 2a of the ball tray 2, and a solder ball 1
And a solder ball replenishing mechanism 8 capable of automatically replenishing the solder balls.

The solder ball replenishing mechanism 8 may be provided at a plurality of positions on the ball tray 2 in some cases.
In this embodiment, the number is one. Further, the vibration generator 6 is an electromagnetic solenoid, and magnetizes the iron core 6b in the coil part 6a on the outer periphery to adsorb and non-adsorb the disc-shaped iron material 2b provided below the ball tray 2. Thus, the ball tray 2 is vibrated.

In addition to these components, there are provided a pickup head table 9 capable of moving the pickup head 5 in the horizontal direction and the vertical direction, a vacuum pump 10 for applying a suction force to the pickup head 5 for sucking the solder balls 1 and the like. I have. The pickup head 5 that has absorbed the solder ball 1 is mounted on an electrode pad such as a semiconductor chip on a substrate mounting table (not shown) by a pickup head table 9, and the solder ball 1 is placed on the electrode pad. Will be mounted.

Around the ball tray 2, a nozzle (not shown) for supplying a gas for preventing oxidation such as nitrogen from a tank (not shown) into the ball tray 2 is provided. Oxidation of the solder balls 1 in 2 can be suppressed.

FIG. 2 is a partially cutaway sectional view showing the structure of the pickup head 5 in FIG.

The pickup head 5 has a substantially rectangular head housing 17, a hollow portion 18 formed inside the head housing 17, and a head housing 17.
In the bottom plate, a solder ball suction hole 19 formed to penetrate the hollow portion 18 and a gas for preventing oxidation from being supplied into the hollow portion 18 from a tank (not shown) or to suck the solder ball 1. A nozzle 20 for discharging air from the hollow portion 18, a light receiving element 21 as a detecting member disposed in a through hole formed in an upper plate of the head housing 17, a solenoid coil and a motor attached to the head housing 17. A head vibration generating member 22 that generates vibration based on operations such as the above. The light receiving element 21
Are a plurality of light receiving element groups formed on the upper surface of the hollow portion 18 corresponding to the area where the solder ball suction holes 19 are provided.

FIG. 2 shows a state in which the solder balls 1 are sucked into the respective solder ball suction holes 19. Also, the head housing 1 is formed so that the suction pattern of the solder ball 1 formed by the solder ball suction hole 19 matches the contact pattern of a semiconductor chip or the like on which the solder ball 1 is finally mounted.
7

The light receiving element 21 detects the presence or absence of light from a light emitting element (not shown) disposed below the pickup head 5. When the light reaches the light receiving element 21, the solder ball suction holes 19 are provided. Indicates that the solder ball 1 has not been adsorbed, and when light has not reached the light receiving element 21,
This means that the solder balls 1 are sucked in all the solder ball suction holes 19.

The solder ball sensor 7 is a magnetic proximity sensor and has a disk-shaped detecting portion 7a having a diameter φ of about 8 mm as shown in FIG. It is provided on the same plane as 2a. The solder ball sensor 7 detects the density of the solder balls 1 from the number of the solder balls 1 existing on the detecting portion 7a, and estimates the amount of solder balls in the entire ball tray 2 by using the density detecting means. If it is determined that the total amount of solder balls in the ball tray 2 is equal to or less than a predetermined value (for example, 30,000), an arithmetic control unit that sends a replenishment command signal to the solder ball replenishment mechanism 8 is provided. Have.

As a specific operation example of the solder ball sensor 7, in the case of this embodiment, when the detected density is equal to or more than a predetermined value (this is referred to as th1), Is determined to be an appropriate amount (30,000 to 35,000 in this example). In this case, the solder ball sensor 7 is kept on, and the detected density is less than the value th1. In the case of (1), it is determined that the total amount of solder balls in the ball tray 2 is smaller than an appropriate amount, and the solder ball sensor 7 is turned off. Therefore, when the solder ball sensor 7 changes from the on state to the off state, the off signal is output to the solder ball replenishing mechanism 8 as a replenishment command signal.

As shown in FIG. 3, the position of the detection unit 7a in the ball tray 2 is not very close to the solder ball replenishment unit A from the solder ball replenishment mechanism 8 and the position of the pickup head 5 Suction operation range (Fig. 3
(A portion surrounded by a broken line L).
This is because the replenished solder balls 1 may easily stay around the solder ball replenishing portion A in the ball tray 2, and the density detected at that portion is a reliability that represents the density of the entire ball tray 2. Is low, and the suction operation range of the pickup head 5 is affected by the suction operation of the pickup head 5. Also in this case, the density detected at that portion is not reliable as a value representing the density of the entire ball tray 2. Because it is low.

When receiving an off signal (replenishment command signal) from the solder ball sensor 7, the solder ball replenishing mechanism 8 receives a predetermined amount of solder from a hopper (not shown) storing the solder balls 1. A ball 1 is supplied into a ball tray 2. The solder balls 1 may be supplied by a method of supplying the solder balls 1 filled in the cup or by a parts feeder method of supplying the solder balls 1 by vibration.

The predetermined appropriate amount of solder balls 1
In the present embodiment, the replenishment amount control when supplying to the ball tray 2 is controlled by the replenishment time. That is, when the off signal (replenishment command signal) is received from the solder ball sensor 7, the replenishment of the solder balls 1 is performed for a predetermined time (for example, 5 seconds). As a result, a substantially constant amount of solder balls 1 can be transferred to the ball tray 2 by one replenishing operation.
Will be replenished within.

The replenishment time is set in advance by checking how much solder ball 1 is replenished per second and by what amount of solder ball should be replenished at one time. be able to. In this embodiment, the setting is such that about 5,000 solder balls 1 (actually, there are cases where the number of suction balls is less than 5,000) are replenished by one replenishing operation.

The operation of such a configuration will be described with reference to FIG.

Here, the operation after the end of one suction operation by the pickup head 5 will be described. First, a certain solder ball suction operation (ball suction to mounting of a semiconductor chip or the like on an electrode pad) (operation procedure S1) is performed. Then, the solder ball density is detected from the number of solder balls 1 existing in the device, and the amount of solder balls in the ball tray 2 is estimated based on the detection result (density) (operation procedure S2). That is, the solder ball sensor 7
When the detected density is equal to or greater than the predetermined value th1, the on state is maintained, and when the detected density is determined to be less than the value th1, the state is turned off, and the replenishment command to the solder ball replenishment mechanism 8 Output a signal.

Here, if the detected density is less than th1, the solder ball sensor 7 is turned off and a replenishment command signal is output to the solder ball replenishment mechanism 8. The solder ball replenishing mechanism 8 receiving the replenishment command signal performs the replenishing operation of the solder ball 1 for a predetermined time (for example, 5 seconds) (operation procedure S3). As a result, the solder balls 1 are refilled in the ball tray 2 for only 5 seconds. In this case, nearly 5000 solder balls 1 are refilled.

When the replenishing operation of the solder balls 1 is completed, the vibration generator 6 operates to apply vibration to the ball tray 2 (operation step S4). In addition, this ball tray 2
Since the end portion is supported on the ball tray support housing 4 by an elastic member 3 such as a leaf spring, the ball tray 2 vibrates when a vibration is applied to the bottom surface 2 a by the vibration generator 6. This vibration may be about 1 to 2 seconds.

As described above, when the ball tray 2 vibrates, the solder balls 1 existing in the ball tray 2 are almost uniformly scattered as a whole without overlapping in the vertical direction. At this time, the state of the solder balls 1 in the ball tray 2 is not overlapped in the vertical direction and is almost uniformly scattered as a whole, and of course, the entire area of the bottom surface 2a in the ball tray 2 In this case, it is desirable that the amount of the solder balls 1 is about 50%.

This is because the amount of the solder ball 1 is too small,
If the density of the scatter is too low, the suction rate of the pickup head 5 decreases, and the solder ball is moved to the suction hole 1 within a predetermined time.
This is because a phenomenon of insufficient adsorption occurs in which all of No. 9 cannot be adsorbed. On the other hand, if the density of the scattering is too high, when the ball tray 2 vibrates, the solder balls 1 interfere with each other and do not jump uniformly to a sufficient height. Table 1 shows such a situation. Table 1
To explain the symbols inside, the ◎ mark is excellent,
A mark indicates good, a mark indicates that there is a problem in practical use, and a mark indicates that it is not suitable for practical use. As can be seen from Table 1, there is no practical problem if the amount of the solder balls 1 is 30 to 70% with respect to the entire area of the bottom surface 2a. 〜60% produces the best results.

[0050]

[Table 1]

By applying the vibration to the ball tray 2 in this way, if the solder balls 1 in the ball tray 2 are not overlapped in the vertical direction and are almost uniformly scattered as a whole, The density is detected by the solder ball sensor 7 (operation procedure S5), and the density is determined to be a predetermined value th.
If the value is 1 or more, the solder ball sensor 7 returns to the on state, but if the density is less than the predetermined value th1,
The refilling operation of the solder balls 1 is performed again by the solder ball replenishing mechanism 8 (operation procedure S6).

When the detection density of the solder ball sensor 7 exceeds a predetermined value th1, the solder ball sensor 7
Is turned on, the operation of the solder ball replenishing mechanism 8 is stopped, the next suction operation by the pickup head 5 becomes possible, and the above-described operation procedure S1 and subsequent steps are repeated. At the time of the suction operation, the ball tray 2 is vibrated by the vibration generator 6, and the solder ball 1 moves away from or arrives at the bottom surface 2a.
In the floating state, a large number of solder balls 1 are sucked on the suction surface of the pickup head 5 (a large number of solder ball suction holes 19 each having a circular hole slightly smaller in diameter than the diameter of the solder ball 1 are arranged). You. Thereafter, the solder balls 1 are mounted on the electrode pads of the inner leads of the film carrier.

It should be noted that once the solder ball 1 replenishment operation (operation procedure S3 in FIG. 4) is performed, the ball tray 2
Is vibrated (operation procedure S4 in FIG. 4), and density detection by the solder ball sensor 7 (operation procedure S5 in FIG. 4) is performed again. One refill of the solder ball is about 5000 in this embodiment. The number of the solder balls 1 may be smaller than the number of the solder balls. However, in some cases, when the suction operation is repeatedly performed by the pickup head 5 (in this embodiment, about 5000 solder balls 1 are formed by one suction operation). This is because the solder balls 1 in the ball tray 2 tend to gradually decrease.

That is, if the suction operation by the pickup head 5 is repeated, even if the solder ball is replenished once into the ball head 2, the appropriate amount of solder ball may not be obtained yet. For this reason, after one solder ball replenishment is performed, the ball tray 2 is vibrated to spread the solder balls 1 uniformly, and then the density is detected again by the solder ball sensor 7. The replenishing operation of the solder ball 1 is repeated until it is turned on (until the density becomes equal to or more than the predetermined value th1).

By performing the above-described operations, a proper amount or a little more (about 30,000 to 35,000 solder balls in this embodiment) is always contained in the ball tray 2. 1 are uniformly scattered without overlapping in the vertical direction. Thereby, the suction operation of the solder ball 1 by the pickup head 5 is
In each case, a stable amount of the solder ball 1 can be sucked. In addition, since the solder balls are always present in the ball tray 2 in an appropriate amount or slightly more, the oxidation of the solder balls 1 can be prevented.

Although the above-described embodiment is an example of a preferred embodiment of the present invention, the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention. is there. For example, in the above embodiment,
Although the solder ball sensor 7 is provided at one position, the solder ball sensor 7 may be provided at a plurality of positions, and processing such as obtaining an average of respective densities obtained from the respective solder ball sensors 7 may be performed. Even when the solder ball sensors 7 are provided at a plurality of locations, it is desirable that the installation locations of the respective detection units 7a satisfy the above-described conditions (such as avoiding the vicinity of the solder ball replenishment unit and the suction range of the pickup head 5).

The solder ball sensor 7 is composed of two parts, a sensor part and a judgment part.
The number is compared with a predetermined value in the determination part, and if the number is greater than or equal to the predetermined value, an on signal is output from the determination part, and if less than the predetermined value, an off signal is output from the determination part. May be. Thus, the solder ball sensor 7
Or the step of estimating the total amount of the solder balls 1 may be omitted, the number may be used instead of the density, and the necessity of replenishment of the solder balls 1 may be determined based on the number.

Further, in the above-described embodiment, when refilling the solder balls 1 into the ball tray 2, the replenishment of the solder balls is performed at one place. However, this is not limited to one place. 2 depending on the size of the ball tray 2
It may be more than the number of places.

Further, the replenishment amount X of the solder ball 1 is not set to X = Y (X <Y as a whole tendency) as compared with the suction amount Y of the pickup head 5 as in the above-described embodiment.
X> Y or X = Y (X> Y as an overall trend)
Furthermore, the overall tendency may be substantially such that X = Y. As described above, various methods can be adopted because the solder ball sensor 7 exists,
This is because it is possible to prevent the number of pieces from becoming too small or too large.

In the above-described embodiment, when the density detected by the solder ball sensor 7 is equal to or less than the predetermined value th1, a certain amount (about 5,000 in the above example) is replenished. However, for example, a predetermined value is set in a plurality of steps such as th1, th2, th3,..., And the density of the solder ball is replenished according to each step. It is also possible to control such that the amount of the refilled solder ball is changed according to the size of the solder ball.

The vibration generator 6 is not a system in which the ball tray 2 is sucked by a solenoid, but is a system in which the ball tray 2 is hit, or the ball tray 2 is placed on the vibration generator 6 and the whole is vertically moved. You may make it do. Further, with respect to the entire area of the bottom surface 2a of the ball tray 2,
When the area of the suction surface of the pickup head 5 is set to 10 to 80%, it becomes preferable in terms of the detection of the solder ball 1, the miniaturization of the device, the workability of the suction of the solder ball 1, and the like.
70% is more preferable, and 40-60%
Is the most preferable. Further, although the solder ball sensor 7 is a magnetic proximity sensor, other types of sensors, such as an optical sensor for detecting the number of solder balls 1 by capturing an image, may be used.

[0062]

As described above, according to the present invention,
By oscillating the solder ball tray, the solder balls existing in the solder ball tray are scattered almost uniformly in the solder ball tray, and it is determined whether or not it is necessary to refill the solder balls. The necessity of replenishment can be accurately determined. Then, based on the result of the determination, if the solder balls need to be replenished, the solder balls are replenished, so that the amount of the solder balls in the solder ball tray can always be kept at an appropriate amount. In addition, it is possible to prevent the solder balls from being oxidized and to stabilize the suction of the solder balls by the pickup head.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an embodiment of a solder ball supply device of the present invention.

FIG. 2 is a cross-sectional view showing a structure of a pickup head used in the solder ball supply device shown in FIG.

FIG. 3 is a diagram illustrating a state where a detection unit of a solder ball sensor in the solder ball supply device illustrated in FIG. 1 is installed on a ball tray;

FIG. 4 is a diagram illustrating an operation procedure of a solder ball amount control method according to the embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 solder ball 2 ball tray (solder ball tray) 2 a bottom surface of ball tray 3 elastic member 4 ball tray support housing 5 pickup head 6 vibration generator 7 solder ball sensor 7 a detection unit of solder ball sensor 8 solder ball replenishing mechanism

Claims (10)

[Claims] 1. An apparatus for detecting an amount of solder balls in a solder ball tray for storing an appropriate amount of solder balls capable of coping with a suction operation of a pickup head, and holding an appropriate amount of solder balls in the solder ball tray. A method of controlling the amount of solder balls for controlling, wherein the solder balls existing in the solder ball tray are scattered almost uniformly on the bottom surface of the solder ball tray by vibrating the solder ball tray, In a state where the solder balls are scattered almost uniformly, it is detected whether or not the solder balls need to be replenished.If it is detected that the solder balls need to be replenished, it is necessary to replenish the solder balls. Characteristic solder ball amount control method. 2. The condition where the solder balls are scattered almost uniformly in the solder ball tray means that the solder balls having an amount occupying 30 to 70% of the area of the bottom surface in the solder ball tray are formed on the bottom surface. 2. The method according to claim 1, wherein the solder balls are scattered almost uniformly over the entire surface. 3. A method of detecting whether it is necessary to replenish solder balls in the solder ball tray is performed by detecting a solder ball density in a predetermined portion in the solder ball tray, and replenishing the solder balls based on the detected density. 3. The method according to claim 1, wherein whether or not it is necessary is determined. 4. A position where the solder ball density is detected in the solder ball tray is at least a position near a solder ball replenishing portion in the solder ball tray and a position avoiding a solder ball suction range by the pickup head. The method according to any one of claims 1 to 3, wherein: 5. When replenishing solder balls to the solder ball tray, the replenishment amount is managed by time, and is equal to or slightly less than a single suction amount by the pickup head for a predetermined time. 5. A replenishing operation of an amount of solder balls is performed.
Item 14. A method for controlling the amount of solder balls according to the above item. 6. A solder ball tray for storing solder balls, a solder ball replenishing mechanism for replenishing the solder balls to the solder ball tray, and a solder ball stored in the solder ball tray for each suction operation. A pickup head that sucks a predetermined amount of the solder ball and transfers the solder ball to the next step; a housing that supports the solder ball tray so that the solder ball tray can vibrate; and a vibration that applies a vibration force to the solder ball tray. A generator and a solder ball sensor that outputs a replenishment command signal to the solder ball replenishment mechanism when it is determined that replenishment of the solder balls present in the solder ball tray is necessary; By vibrating the solder ball tray by a vibration generator, the solder balls existing in the solder ball tray are removed from the solder ball tray. In the state where the solder balls are scattered almost uniformly on the bottom surface of the solder ball, and in a state where the solder balls are scattered almost uniformly, the solder ball sensor detects whether or not it is necessary to replenish the solder balls present in the solder ball tray, If it is detected that the solder ball needs to be refilled,
A solder ball supply device which outputs a replenishment command signal to the solder ball replenishment mechanism. 7. A solder ball sensor comprising: a density detecting means for measuring a density of the solder ball in a predetermined portion in the solder ball tray; and whether or not the solder ball needs to be replenished based on the measured density data. 7. The solder ball supply device according to claim 6, comprising arithmetic control means for judging the condition. 8. The solder ball supply device according to claim 7, wherein said density detecting means is a proximity sensor. 9. The detection position of the solder ball density in the solder ball tray of the solder ball sensor at least avoids a vicinity of a solder ball replenishing portion in the solder ball tray and a solder ball suction range by the pickup head. The solder ball supply device according to claim 6, wherein the position is a position. 10. When the solder ball replenishing mechanism replenishes the solder ball to the solder ball tray, the replenishing amount is managed by time, and the amount of one suction by the pickup head is determined for a predetermined time. 7. A refilling operation of a slightly smaller amount of solder balls is performed.
10. The solder ball supply device according to any one of items 1 to 9.