JP2003179089A - Conductive ball mounting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase the productivity of a solder ball mounting apparatus by preventing the failure to chuck or excessive chucking of solder balls by an alignment mask. <P>SOLUTION: In order to control the number of solder balls 1 in a solder ball container 2 within a prescribed range, the solder ball mounting apparatus is provided with a CCD camera 64 for photographing the inside of the solder ball container 2; and an image processing means 65 which calculates a dominant area of the solder balls 1 in the solder ball container 2 and then calculates the number of solder balls 1 from the calculated dominant area. By remarkably reducing the number of failures to chuck or excessive chucking of the solder balls by means of the alignment mask which are generated when the alignment mask chucks the solder balls to reduce the number of retried chucking, the productivity of the solder ball mounting apparatus can be increased. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a BGA (Ball).
Grid Array), CSP (ChipSize)
Package or Chip Scale Pa
and a conductive ball mounting device that mounts a conductive ball for forming the bump on a connection terminal of a package that uses a conductive protruding contact (hereinafter referred to as a bump) as a connection material with a mounting substrate, such as a package. Is.

[0002]

2. Description of the Related Art As a structure for connecting a package having a large number of connection terminals (input / output terminals) such as a semiconductor package using an LSI to a mounting substrate, a structure in which bumps are formed on the connection terminals of the package is adopted. ing. The bumps are formed by mounting conductive balls (for example, solder balls, hereinafter referred to as solder balls) on the connection terminals of the package and performing reflow (heating and melting).

As a solder ball mounting device for mounting the solder balls on the connection terminals of the package, flux is adhered to the solder balls absorbed by the alignment mask,
There are a device mounted on a connection terminal of a package and a device mounted with a flux on the connection terminal of the package in advance and then mounting a solder ball adsorbed by an alignment mask on the flux.

[0004]

In any of the solder ball mounting devices described above, the solder balls are attracted to the alignment mask by the steps shown in FIG. That is, above the solder ball container 2 accommodating the solder balls 1, the alignment mask 7 connected to the vacuum source 5 via the pipe 3 and having the suction holes 6 is arranged. Then, the solder balls 1 housed by vibrating the solder ball container 2
And the suction holes 6 are connected to the vacuum source 5 and vacuum suction is performed to attach the solder balls 1 to the suction holes 6 of the alignment mask 7.
Is adsorbed.

At this time, as shown in FIG. 11, in the suction holes 6 of the alignment mask 7, there are suction holes 6 in which the solder balls 1 cannot be sucked (unsucked), or as shown in FIG. Of the suction holes 6 of 7, the suction holes 6 that simultaneously suck a plurality of solder balls 1 (excessive suction) may occur. Then, such non-adsorption or excessive adsorption causes bump defects after reflow.

In order to prevent such a phenomenon, after the solder balls are sucked by the alignment mask, the sucking surface is CCD.
It is a common practice to take an image with a camera, process the image, and inspect the suction state. Then, when non-sucking or excessive sucking occurs, the solder ball sucked on the alignment mask is discarded, and a retry operation is performed to suck the solder ball again on the alignment mask. Therefore, the larger the number of suction holes of the alignment mask, that is, the larger the number of solder balls sucked in one suction operation, the more the number of retry operations occurs, which lowers the productivity of the solder ball mounting apparatus. I am letting you.

When solder balls are adsorbed by the alignment mask, non-adsorption is likely to occur when the number of solder balls in the solder ball container is small, and excess adsorption occurs when the number of solder balls is large. Easier to do. Therefore, it is required to manage the number of solder balls in the solder ball container within an appropriate range (specified range).

As a method for controlling the number of solder balls in the solder ball container within a prescribed range, the consumption amount of the solder balls is calculated from the number of times the solder balls are aligned by the alignment mask (the number of times the solder balls are taken out), and When the number of solder balls reaches the lower limit of the specified range, new solder balls are supplied into the solder ball container.

However, the solder balls in the solder ball container are not only adsorbed and taken out by the alignment mask, but also the surface of the solder balls is extremely discolored, or a plurality of solder balls are combined into one. It may be discarded due to defective solder balls themselves, such as mixing of different sizes, and there is unpredictable consumption. Therefore, it is difficult to accurately control the number of solder balls in the solder ball container.

In view of the above circumstances, the present invention can accurately control the number of solder balls in the solder ball container within a prescribed range even if there is an unpredictable consumption of the solder balls, thereby improving the productivity. It is an object of the present invention to provide a solder ball mounting device capable of performing the above.

[0011]

In order to achieve the above object, claim 1 of the present invention provides a mounting portion (25) for positioning a package (12) having a plurality of connection terminals,
A solder ball container (2) for accommodating a plurality of solder balls (1), a solder ball supplier (57) having a bottom surface of the solder ball container (2) as a low reflection surface, and a vacuum source, A plurality of suction holes are formed on the suction surface in the same arrangement as the plurality of connection terminals formed on the package (12),
The solder ball (1) is sucked and taken out from the solder ball supply section (57) to the suction hole, and the mounting section (25)
An alignment mask (7) for mounting the solder balls (1) on the connection terminals of the package (12) positioned in the package, and a solder ball container (2) for the solder ball supply section (57).
Based on the measurement means (63) for measuring the occupied area of the solder ball (1) on the bottom surface of the solder ball and calculating the number of solder balls (1) from the occupied area, and the calculation result by the measuring means (63). A solder ball (1) calculated by the measuring means, and a control means (67) for stopping the solder ball mounting device when the number of the solder balls (1) is out of the specified range. Onboard equipment.

According to a second aspect of the present invention, in the first aspect of the invention, the measuring means (63) is arranged above the solder ball supply section (57), and the solder ball container (2) is provided. A CCD camera (64) for taking a picture of the inside,
Image data output from the CCD camera (64) is processed to calculate an occupied area of the solder ball (1) in the solder ball container (2), and the occupied area is calculated in the solder ball container (2). The image forming means (65) for calculating the number of the solder balls (1) in (1) above.

According to a third aspect of the present invention, in the invention according to the first aspect, the measuring means (63) receives the reflected light from the inside of the solder ball container (2) and is proportional to the amount of the received light. The number of solder balls (1) in the solder ball container (2) is calculated based on the optical sensor (81) that converts the voltage signal and the magnitude of the voltage signal output from the optical sensor (81). Signal processing means (82)
The solder ball mounting device is characterized by comprising:

The reference numerals in parentheses indicate the corresponding elements in the drawings, and the present description is not limited to the description of the drawings.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 show an embodiment of the present invention. FIG. 1 is a perspective view of a solder ball mounting device to which the present invention is applied, and FIG. 2 is a detection part of the solder ball mounting device of the present invention. FIG. 3 is a configuration diagram, FIG. 3 is a flowchart showing a procedure for measuring the number of solder balls by the detection unit in FIG. 2, and FIG. 4 is a characteristic diagram showing a correlation between the occupied area of the solder balls in the solder ball container and the number of solder balls. 5 is a configuration diagram of a solder ball replenishing device used in a solder ball mounting device, and FIG. 6 is an operation explanatory diagram of the solder ball replenishing device in FIG.

In FIG. 1, a solder ball mounting device 1 is provided.
0 is a carrier unit 13 arranged on the base 11 for supplying and discharging the package 12 on which the solder balls 1 are mounted;
A mounting portion 25 for positioning the package 12, a driving portion 30 for moving the flux supplying jig 56 and the alignment mask 7, a flux supplying portion 52 for supplying the flux 9 to the package 12 positioned by the mounting portion 25, and a flux. It has a solder ball supply part 57 for mounting the solder ball 1 on the connection terminal of the package 12 to which 9 is applied, and a detection part 61 for detecting the position of the connection terminal of the package 12 positioned at the mounting position. .

The carrying section 13 is rotatably supported so as to cross the groove 15 at the upper portions of both ends of the groove 15 penetrating the upper surface of the base 11 in the direction of arrow X (left and right direction in FIG. 1). A shaft 16 is provided. A pair of pulleys 17 are fixed to both ends of the shaft 16, and a belt 19 is provided on the pulley 17 in parallel with the longitudinal direction of the groove 15 (direction of arrow X).
Have been passed over. One of the shafts 16 is connected to and driven by a motor 20 fixed to the base 11.

In addition, the transport unit 13 includes a plurality of packages 1.
2 has a carrier 21 on which the carrier 21 is placed, and the carrier 21 is placed on the belt 19 so that an arrow X
Transport in the direction. Inside the groove 15, the cylinder 22 is positioned below the movement path of the carrier 21.
Are arranged. A stopper 23 is attached to the cylinder 22 so as to be movable back and forth with respect to the movement path of the carrier 21.

Therefore, by placing the carrier 21 on the belt 19 and operating the motor 20, the carrier 21 can be conveyed in the direction of the arrow X. Further, at this time, if the stopper 23 is made to project in the movement path of the carrier 21 by the operation of the cylinder 22, the carrier 2
1 can be stopped by bringing 1 into contact with the stopper 23.

The mounting portion 25 is located below the groove 15 and has a linear guide means 26 having a slide member (not shown) movable in the arrow X direction and a screw feed mechanism (not shown). Motor 27 for driving the slide member
Is equipped with. The cylinder 29 is formed in the slide member such that the movable member penetrates the bottom surface of the groove 15 slidably in the arrow X direction and the arrow Z direction (vertical direction in the drawing).
Is fixed, and the mounting table 28 is fixed to the movable member of the cylinder 29.

Therefore, by operating the cylinder 29 and raising the mounting table 28, the carrier 21 stopped by the stopper 23 can be moved from the belt 19 to the upper mounting position. In addition, by operating the motor 27, the package 12 on the carrier 21
The packages 12 arranged on the carrier 21 can be sequentially moved to the mounting position by sequentially moving the arrangement intervals of.

The drive unit 30 is provided with a pair of columns 31 fixed in parallel at a predetermined interval on both ends of the base 11 in the direction of arrow X so as to straddle the groove 15.
Rails 32 forming linear guides are fixed to the upper end surfaces of the columns 31 in parallel at predetermined intervals. A ball screw 35 is rotatably supported on the upper end surface of one column 31 via a bearing 33 in parallel with the rail 32 at a predetermined interval. Then, one end of the ball screw 35 is connected to a motor 36 fixed to the column 31.

The slider 37 has a bearing (not shown) slidably fitted to the rail 32 and a nut (not shown) screwed with the ball screw 35. Then, by the operation of the motor 36, the motor 36 is moved along the rail 32 in the arrow Y direction (the front-back direction of the paper surface of FIG. 1).

On the front surface of the slider 37, a pair of rails 39 are fixed above and below the slider 37 so as to extend in the direction of the arrow X in parallel with each other at predetermined intervals and to form a linear guide device. Also,
A ball screw 41 is rotatably supported on the front surface of the slider 37 via a bearing 40 so as to be located between the rails 39 in parallel with the rail 39 at a predetermined interval.
Then, one end of this ball screw 41 is connected to a motor 42 fixed to the slider 37.

The slide plate 43 has the rail 39.
A bearing (not shown) slidably fitted to the ball screw 41 and a nut (not shown) screwed onto the ball screw 41 are provided. Then, by the operation of the motor 42, the rail 3
Move along arrow 9 in the direction of arrow X.

On the front surface of the slide plate 43, a pair of rails 45, which extend in the arrow Z direction and are parallel to each other at a predetermined interval and which constitute a linear guide device, are fixed. A ball screw 47 is rotatably supported on the front surface of the slide plate 43 via a bearing 46 so as to be positioned between the rails 45 in parallel with the rail 45 at a predetermined interval. Then, one end of the ball screw 47 is connected to a motor 49 fixed to the slide plate 43.

The mount head 50 includes a bearing 51 slidably fitted to the rail 45 and a nut (not shown) screwed to the ball screw 47. The mount head 50 is mounted on the rail 45 by the operation of the motor 49. Move along arrow Z.

Therefore, the drive unit 30 can move the mount head 50 to an arbitrary position in the X, Y, and Z directions by operating the motor 36, the motor 42, and the motor 49.

The flux supply section 52 comprises a flux supply means 53 supported by the base 11 and a flux supply jig 56 supported by the mount head 50.

The flux supply means 53 is provided with a flux container 54 having a flat surface formed therein, and a squeegee 55 for scraping and leveling the flux 9 supplied into the flux container 54. Then, the squeegee 55 is opposed to the flat surface of the flux container 54 at a predetermined interval, moved in the arrow X direction, and the flux 9 supplied into the flux container 54 is scraped and leveled, whereby the flux 9
To form a film.

The flux supply jig 56 is provided with a plurality of pins (not shown) that are individually movable in the arrow Z direction in the same arrangement as that of the connection terminals of the package 12. Then, attach the tip of each pin to the flux 9
The flux 9 is attached to the tip of the pin by immersing it in the film of 1. and the tip of the pin to which the flux 9 is attached is brought into contact with the connection terminal of the package 12.
The flux 9 is transferred to the connection terminals of the package 12.

The solder ball supply unit 57 comprises a solder ball supply means 59 supported by the base 11 and an alignment mask 7 supported by the mount head 50 for adsorbing and holding the solder balls 1.

The solder ball supply means 59 is disposed on the base 11 and is formed so that the bottom surface has a low reflectance, and the solder ball container 2 for accommodating a plurality of solder balls 1 and the inside of the solder ball container 2 are provided. A vibration source (not shown) is provided for floating the solder balls 1 housed in (1) toward the alignment mask 7.

Accordingly, the alignment mask 7 is arranged so as to cover the opening of the solder ball container 2, and the alignment mask 7 is supplied with a vacuum pressure and the solder ball container 2 is vibrated to accommodate the solder contained therein. Float the ball 1. Then, since the solder balls 1 float from the bottom of the solder ball container 2 toward the suction surface of the alignment mask 7, the floating solder balls 1 are attracted to the suction holes by the flow of air sucked from the suction holes 6. , Held by adsorption.

As shown in FIG. 1, the detector 61 includes a ring light 62 mounted on the mount head 50,
It has a CCD camera 64 and, as shown in FIG. 2, a monitor 66 for displaying a photographed image of the CCD camera 64. Further, the CCD camera 64 and the image processing means 65 for processing the photographed image constitute the measuring means 63.

Then, when the CCD camera 64 photographs the connection terminal of the package 12, the image processing means 65 calculates the position of the connection terminal of the package 12. When the CCD camera 64 photographs the solder ball container 2, the number of solder balls 1 is calculated.

When the CCD camera 64 photographs the connection terminal of the package 12, the control means 67 moves the mount head 50 according to the position of the connection terminal of the package 12 calculated by the image processing means 65. Also, CC
When the D camera 64 takes an image of the solder ball container 2, the solder ball 1 in the solder ball container 2 is judged to be in excess or deficiency based on the number of solder balls 1 calculated by the image processing means 65, and the solder balls are determined. Controls such as continuing the work in the mounting device 10 and stopping the solder ball mounting device 10 to oscillate an alarm are performed.

As shown in FIG. 5, the solder ball automatic replenishing device 70 is fixed to, for example, the column 31 (see FIG. 1) and accommodates the solder balls 1, and the hopper 71 and the solder ball container 2. And a cylinder 73 which is swingably supported by the column 31 and holds an intermediate portion of the flexible pipe 72.

With the above structure, the conductive ball mounting apparatus 10 operates the cylinder 22 when the carrier 21 having the package 12 mounted thereon is supplied onto the belt 19 of the transport section 13 from the left side of FIG. The stopper 23 is raised. Then, the motor 20 operates to cause the belt 19 to travel and convey the carrier 21 in the arrow X direction from the left side to the right side in FIG. And the carrier 21 is the stopper 2
Upon contact with 3, the carrier 21 is stopped in that position. When the conveyance of the carrier 21 is completed, the motor 20 stops and the traveling of the belt 19 also stops. Then, the cylinder 22 operates to lower the stopper 23.

The cylinder 29 of the mounting portion 25 operates to raise the mounting table 28, push up the carrier 21 mounted on the belt 19 with the mounting table 28, and mount the package 12 mounted on the carrier 21. Position in position.

On the other hand, the drive unit 30 operates the motor 36 and the motor 42 to move the CCD camera 64 to a position facing the solder ball container 2. At the same time, the motor 49 is operated to move the CCD camera 64 in the arrow Z direction,
The CCD camera 64 is focused on the bottom surface of the solder ball container 2.

In this state, the ring light 62 is turned on and the entire bottom surface inside the solder ball container 2 is photographed by the CCD camera 64 (step S1 in FIG. 3, hereinafter simply referred to as step S ○). At this time, the captured image can be displayed on the monitor 66 as shown in FIG. This image is an image 2a of the bottom surface of the relatively dark solder ball container 2.
And a relatively bright image 1a of the solder ball 1 that reflects the light of the ring light 62.

The image processing means 65 to which the image data is applied from the CCD camera 64 compares each element forming the CCD with a preset threshold value and performs binarization (step S2). For example, an element brighter than the threshold is set to "1" and an element darker than the threshold is set to "0".

The image processing means 65 counts the number of elements set to "1" in the binarized image data (step S3). Then, the total number (known) of the elements forming the CCD is compared with the counted number of elements, and the ratio of "1" in the image data is multiplied by the bottom area (known) of the solder ball container 2, It is calculated as the occupied area of the solder ball 1 (step S4).

Further, the image processing means 65 multiplies the calculated occupied area of the solder ball 1 by a predetermined coefficient (the number of solder balls 1 per unit area) to solder ball container 2
The number of solder balls 1 therein is calculated (step S5).
The coefficient depends on the diameter of the solder ball 1.

There is a correlation as shown in FIG. 4 between the occupied area of the solder balls and the number of solder balls. When the area occupied by the solder balls is S, the number of solder balls having a diameter of 0.76 mm is N1, the number of solder balls having a diameter of 0.5 mm is N2, and the number of solder balls having a diameter of 0.3 mm is N3. , N1 <N2 <N3. That is, even if the occupied area is the same, the number of solder balls in the solder ball container differs depending on the diameter of the solder balls.

The control means 67 controls the number of the solder balls 1 in the solder ball container 2 applied from the image processing means 65 and the lower limit of the preset specified range (specified value lower limit).
And are compared (step S6). When the number of solder balls 1 in the solder ball container 2 is larger than the lower limit of the specified value, the number of solder balls 1 is compared with the upper limit of the specified range (upper limit of the specified value) (step S7).

When the number of solder balls 1 in the solder ball container 2 is less than the upper limit of the specified value, the motors 36, 42 and 49 of the drive unit 30 are operated to move the alignment mask 7 to the solder ball container 2. (Step S8), the mounting work is started.

In step S6, the solder ball container 2
If the number of solder balls 1 therein is less than the lower limit of the specified value, the solder ball mounting device 10 is stopped (step S9). Then, the cylinder 73 of the solder ball replenishing device 70 is operated to push down the intermediate portion of the flexible pipe 72 as shown in FIG.

Then, the flexible pipe 72 is inclined so as to descend from the hopper 71 toward the solder ball container 2, and the solder balls 1 in the flexible pipe 72 and the hopper 71 face the solder ball container 2. And is drained off and replenished (step S10).

To replenish the solder balls 1, for example, after replenishing the solder balls 1 for a certain period of time, the cylinder 73 is operated to move the flexible pipe 72 as shown in FIG.
The flow of the solder balls 1 is stopped and the replenishment is stopped by pulling up the intermediate portion of the. When the replenishment of the solder balls 1 is completed, the steps S1 to S6 are repeated.

The solder balls 1 may be replenished manually. When replenishing the solder balls 1 manually, an alarm can be generated when the solder ball mounting device 10 is stopped.

On the other hand, when the number of solder balls 1 in the solder ball container 2 is larger than the upper limit of the specified value in step S7, the solder ball mounting device 10 is stopped (step S11). At the same time, an alarm is generated (step S12). Then, when a part of the solder balls 1 in the solder ball container 2 is discharged by a manual operation of the operator (step S13) and a restart switch (not shown) is pressed, the steps S1 to S7 are repeated. .

In this way, the number of solder balls 1 in the solder ball container 2 is measured, and the solder balls 1 are replenished,
Since the discharge is performed, the number of solder balls 1 in the solder ball container 2 can be controlled so as to be within the specified range.

The alarm can be displayed by sounding a bell, a buzzer or the like and turning on a lamp.

When the number of solder balls 1 in the solder ball container 2 is within the specified range, the motor 3 of the drive unit 30 is
6, the motor 42 and the motor 49 are operated to move the mount head 50 to move the alignment mask 7 to the solder ball container 2 and the flux supply jig 56 to the flux container 54 of the flux supply means 53. Then, the tips of the pins of the flux supply jig 56 are immersed in the thin film-like flux 9 formed in the flux container 54, and the flux 9 is attached to the tips of the pins.

On the other hand, the alignment mask 7 covers the opening of the solder ball container 2 and a vacuum pressure is supplied through the pipe 3. At the same time, the solder ball container 2 is vibrated to float the solder balls 1 contained therein. When a predetermined adsorption time has elapsed, the vibration of the solder ball container 2 is stopped and the adsorption process is completed.

The motor 36, the motor 42 and the motor 49 of the drive unit 30 are operated to move the mount head 50 to the arrow X,
The CCD camera 64 is moved in the Y and Z directions to a position facing the package 12 at the mounting position. Then, the ring light 62 is turned on and the package 12 is photographed by the CCD camera 64. The image processing means 65 extracts the image of the connection terminal of the package 12 from the photographed image data, calculates the position thereof, and sends the calculation result to the control means 67.

The control means 67 actuates the motor 36 and the motor 42 of the drive section 30 based on the position data of the connection terminals of the package 12 inputted from the image processing means 65, and sets the pins of the flux supply jig 56 to the package 12. Move to a position facing the connection terminal of. Then, the motor 49 is operated, the mount head 50 is lowered, the pins of the flux supply jig 56 are brought into contact with the connection terminals of the package 12, and the flux 9 attached to the pins is transferred to the connection terminals and supplied.

When the supply of the flux 9 is completed, the motor 4
After raising the mount head 50 to a predetermined position by the operation of 9, the motor 36 and the motor 42 are operated,
The solder balls 1 suction-held on the alignment mask 7 are opposed to the connection terminals of the package 12 to which the flux 9 is supplied. Then, the motor 49 is operated to lower the mount head 50 to the position where the solder ball 1 comes into contact with the connection terminal of the package 12.

After stopping the motor 49, the alignment mask 7
The vacuum pressure supplied to the device is cut off, and the inside of the alignment mask 7 is communicated with the atmospheric pressure. Then, the suction force by the vacuum pressure is released, and the solder balls 1 are released from the alignment mask 7.
In this state, the motor 49 operates and the mount head 50
When the (alignment mask 7) is raised, the solder balls 1 remain on the connection terminals of the package 12 due to the adhesive force of the flux 9, and are mounted on the connection terminals of the package 12 from the alignment mask 7.

When the mount head 50 rises, the motor 27 of the mounting portion 25 operates to move the mounting table 28 to the carrier 2
The package 12 placed on 1 is moved by the placement interval, and the next package 12 is moved to the loading position.

When the solder balls 1 are mounted on all the packages 12 mounted on the carrier 21 by repeating such operations, the cylinder 29 of the mounting portion 25 is mounted.
Is operated, the mounting table 28 is lowered, and the carrier 21 is mounted on the belt 19 of the transport unit 13. Then, the motor 2
0 operates to run the belt 19, and the carrier 21 is conveyed toward the right side of FIG. 1 and discharged.

According to the above description, the alignment mask 7
Each time the solder ball 1 is absorbed by the solder ball container 2
The number of solder balls 1 inside is measured,
The measurement interval of the number of solder balls 1 can be set appropriately.

Further, in the above embodiment, the measuring means 63
The CCD camera 64 and the image processing means 65 described above are configured to share the number of the solder balls 1 and the detection of the connection terminals of the package 12. However, a dedicated photographing means and image processing means are provided respectively. Good.

7 to 9 show another embodiment of the detector for measuring the number of solder balls in the solder ball container. FIG. 7 is a block diagram of the detector of the solder ball mounting apparatus. 8 is a schematic diagram showing the field of view of the optical sensor of the detection unit in FIG. 7, and FIG. 9 is a characteristic diagram showing the correlation between the output voltage of the optical sensor and the number of solder balls.

In the figure, the same parts as those in FIGS. 1 and 2 are designated by the same reference numerals. The solder ball container 2 that houses the solder balls 1 is arranged on the base via a piezoelectric vibrator 76 connected to an oscillator 75.

A ring light 79 connected to an illumination power source 77 and an optical sensor 81 having a condenser lens 80 are integrally combined to face the solder ball container 2 and the mount head 50 (see FIG. 1). Not to interfere with
It is arranged in the column 31 (see FIG. 1). The signal processing means 82 is connected to the optical sensor 81, and
The number of solder balls 1 in the solder ball container 2 is calculated based on the output voltage applied from. The measuring unit 63 includes an optical sensor 81 and a signal processing unit 82.

With such a configuration, when the optical sensor 81 can see through the solder ball container 2, the illumination power supply 77
The ring light 79 is turned on by the electric power from the. The reflected light from the inside (bottom surface) of the solder ball container 2 illuminated by the ring light 79 is received by the optical sensor 81 through the condenser lens 80.

At this time, reflected light having a field of view as shown in FIG. 8 is incident on the optical sensor 81. In this field of view,
The bright reflected light 1a from the solder ball 1 and the dark reflected light 2a from the bottom surface of the solder ball container 2 are mixed.
Then, the optical sensor 81 outputs a voltage proportional to the amount of received reflected light.

The signal processing means 82 calculates the area occupied by the solder balls 1 in the solder ball container 2 based on the output voltage applied from the optical sensor 81, and calculates the number of solder balls 1 from the occupied area. , To the control means 67.

That is, when the number of solder balls 1 in the solder ball container 2 is large and the area occupied by the solder balls 1 on the bottom surface is large, the output voltage output from the optical sensor 81 is high, and the number of solder balls 1 is large. When the area occupied by the solder balls 1 on the bottom surface is small, the output voltage output from the optical sensor 81 is low.
Therefore, by detecting the output voltage of the optical sensor 81, the size of the occupied area of the solder ball 1 in the solder ball container 2 can be detected.

Further, the relationship between the occupied area of the solder balls 1 in the solder ball container 2 and the number of the solder balls 1 differs depending on the diameter of the solder balls 1 as in the above embodiment. Therefore, the number of solder balls 1 in the solder ball container 2 can be calculated by multiplying the detected occupied area by a coefficient (the number of solder balls per unit area) corresponding to the size of the solder balls 1. .

If the correlation between the output voltage of the optical sensor and the number of solder balls as shown in FIG. 9 is obtained for each solder ball diameter, the number of solder balls can be directly calculated from the output voltage of the optical sensor. It can also be calculated.

On the other hand, the control means 67 to which the number of the solder balls 1 in the solder ball container 2 is applied from the signal processing means 82 controls the solder ball mounting device as in the above-mentioned embodiment.

The method of floating the solder balls is as follows.
In addition to the above-mentioned vibration, it may be due to the ejection of compressed air. As shown in FIG. 1, the solder ball mounting device may be configured such that the flux and the solder balls are transferred and mounted on the package respectively, or the flux is attached to the solder balls adsorbed by the alignment mask and the package is mounted. It may be configured to be installed in.

[0077]

As described above, according to the present invention, the area occupied by the solder balls on the bottom surface of the solder ball container is detected, and the number of solder balls in the solder ball container is calculated based on the occupied area. Therefore, the number of solder balls can be accurately measured. Therefore, it becomes possible to control the number of solder balls in the solder ball container within a specified range with high accuracy, and to reduce the occurrence of non-adsorption or excess adsorption of the solder balls by the alignment mask to improve the productivity. Can be done.

[Brief description of drawings]

FIG. 1 is a perspective view of a solder ball mounting device to which the present invention is applied.

FIG. 2 is a configuration diagram of a detection unit of the solder ball mounting device in FIG.

3 is a flowchart showing a procedure for measuring the number of solder balls by the detection unit in FIG.

FIG. 4 is a characteristic diagram showing a correlation between an occupied area of solder balls and the number of solder balls in a solder ball container.

FIG. 5 is a configuration diagram of a solder ball replenishing device used in a solder ball mounting device.

FIG. 6 is an operation explanatory view of the solder ball replenishing device in FIG.

FIG. 7 is a configuration diagram of a detection unit of the solder ball mounting device.

8 is a schematic diagram showing a field of view of an optical sensor of the detection unit in FIG.

FIG. 9 is a characteristic diagram showing the correlation between the output voltage of the optical sensor and the number of solder balls.

FIG. 10 is a configuration diagram showing a solder ball suction process using an alignment mask.

FIG. 11 is an explanatory diagram showing a state where solder balls have not been adsorbed on the alignment mask.

FIG. 12 is an explanatory diagram showing a state in which excess solder balls are attracted to the alignment mask.

[Explanation of symbols]

1 ... Conductive ball (solder ball) 2. Conductive ball container (solder ball container) 7 ... Alignment mask 12 ... Package 25 ... Mounting part 57 ... Conductive ball supply unit (solder ball supply unit) 63 ... Measuring means 64 ... CCD camera 65 ... Image processing means 67 ... Control means 81 ... Optical sensor 82 ... Signal processing means

Claims (3)

[Claims] 1. A mounting portion for positioning a package in which a plurality of connection terminals are formed, and a conductive ball container accommodating a plurality of conductive balls, wherein the bottom surface of the conductive ball container is a low reflection surface. A conductive ball supply unit is connected to a vacuum source, and a plurality of suction holes are formed on the suction surface in the same arrangement as the plurality of connection terminals formed on the package. An alignment mask for picking up and picking up the conductive balls and mounting the conductive balls on the connection terminals of the package positioned on the mounting portion; and occupying the conductive balls on the bottom surface of the conductive ball container of the conductive ball supply portion. A measuring unit that measures the area and calculates the number of conductive balls from the occupied area, and the number of solder balls calculated by the measuring unit based on the calculation result by the measuring unit If you are out of range, and a control means for stopping the conductive ball mounting apparatus, and the provided, characterized in that, the conductive ball mounting apparatus. 2. The conductive ball container based on a CCD camera arranged above the conductive ball supply unit for photographing the inside of the conductive ball container and image data output from the CCD camera. 2. The image processing means for calculating the occupied area of the conductive balls in the inside, and calculating the number of the conductive balls in the conductive ball container from the occupied area. Conductive ball mounting device. 3. The optical sensor for receiving the reflected light from the conductive ball container and converting it into a voltage proportional to the amount of the received light, and the measuring means for adjusting the magnitude of the voltage signal output from the optical sensor. The conductive ball mounting device according to claim 1, further comprising a signal processing unit configured to calculate the number of conductive balls in the conductive ball container based on the signal processing unit.