JP2003179088A - Conductive ball mounting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solder ball mounting apparatus which is so designed to precisely control the number of solder balls in a solder ball container within a prescribed range. <P>SOLUTION: The solder ball mounting apparatus comprises a container 2 for storing a plurality of solder balls 1; a counter 69 which measures the total floating time of the solder balls 1 by counting clock signals from an oscillator 67 only while reflected light from the solder balls 1 floating in the container 2 is received by a light blocking sensor 66; and a calculating means 70 which calculates the number of the solder balls 1 in the container 2 based on the measurement result of the counter 69. From the correlation between the total floating time and the number of the solder balls, the number of the solder balls 1 in the container 2 can be precisely controlled, increasing the productivity. <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 suck the solder balls 1 into the suction holes 6 of the alignment mask 7.

At this time, as shown in FIG. 6, 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 1 are sucked by the alignment mask 7, the suction surface is C
An image is picked up by a CD camera, the image is processed by an image processing means, and the suction state of the solder balls 1 by the alignment mask 7 is inspected. Then, when non-sucking or excessive sucking occurs, all the solder balls 1 sucked by the alignment mask 7 are discarded, and the retry operation of again sucking the solder balls 1 by the alignment mask 7 is performed. Therefore, as the number of suction holes 6 of the alignment mask 7 increases,
That is, the larger the number of solder balls that are adsorbed in one adsorption operation, the greater the number of occurrences of the retry operation and the lower the productivity.

When the solder mask 1 is attracted by the alignment mask 7, when the number of the solder balls 1 in the solder ball container 2 is small, non-adsorption is likely to occur, and when the number of the solder balls 1 is large. However, excess adsorption is likely to occur. Therefore, the solder balls 1 in the solder ball container 2
Is required to be controlled within a proper range.

As a method for controlling the number of solder balls 1 in the solder ball container 2 within an appropriate range, the consumption amount of the solder balls 1 is calculated from the number of times the solder balls 1 are aligned by the alignment mask 7 (the number of times the solder balls 1 are taken out). In addition, when the number of solder balls 1 in the solder ball container 2 reaches the lower limit of the specified range, new solder balls 1 are supplied into the solder ball container 2.

However, the solder balls 1 in the solder ball container 2 are not only sucked out by the alignment mask 7 and taken out, but also the surface of the solder balls 1 is extremely discolored,
The solder balls 1 may be discarded due to a defect in the solder balls 1 themselves, such as a single solder ball 1 or a mixture of solder balls 1 having different sizes. Therefore, the solder balls 1 in the solder ball container 2
It was difficult to manage the number of

In view of the above circumstances, the present invention accurately manages the number of solder balls in a solder ball container within an appropriate range even if the consumption of solder balls is unpredictable.
An object of the present invention is to provide a solder ball mounting device capable of improving productivity.

[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 supply section (59) having a container (2) containing a plurality of solder balls (1), 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), and the solder balls (1) are sucked from the solder ball supply section (59) to the suction holes. In the container (2) of the solder ball supply part (59), which is taken out and the solder mask (1) is mounted on the connection terminals of the package (12) positioned on the mounting part (25). Based on the measurement means (68) for measuring the number of the solder balls (1) and the measurement result by the measurement means (68), when the number of the solder balls (1) is less than the specified range, the container (2) The solder ball (1) is instructed to be replenished in the inside, and when the number of the solder balls (1) exceeds the specified range, an alarm is generated and the solder ball mounting device (10)
And a control means (71) for stopping the operation of the conductive ball mounting apparatus.

According to a second aspect of the present invention, in the invention according to the first aspect, the solder ball supply section (59) is
The measuring means (68) has a floating means (4) for floating the solder balls (1) in the container (2), the measuring means (68) oscillates a clock signal of a constant frequency, and a projected light beam. A light-shielding sensor (66) of a reflection type for detecting the reflected light of the solder ball (1) that traverses the oscillator, and the oscillator (67) while the light-shielding sensor (66) receives the reflected light from the solder ball (1). ) And a counter (69) for counting the clock signal oscillated from
The solder ball mounting device is characterized by having a computing means (70) for computing the number of solder balls (1) based on the count value of 9).

The reference numerals in parentheses are for convenience of showing the corresponding elements in the drawings, and therefore the present description is not limited to the description in the drawings.

[0014]

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 apparatus to which the present invention is applied, FIG. 2 is a configuration diagram of a measuring means according to the present invention, and FIG. 2 is a time chart showing the measuring method of the measuring means in FIG. 2, and FIG. 4 is a characteristic diagram showing the correlation between the total floating time of solder balls and the number of solder balls.

In FIG. 1, a solder ball mounting device 10 is provided.
Is a drive unit which is arranged on the base 11 and which supplies and discharges the package 12 on which the solder balls 1 are mounted, the mounting unit 25 which positions the package, the flux supply jig 56 and the alignment mask 7. Part 30
A flux supply section 51 for supplying the flux 9 to the package 12 positioned by the mounting section 25; a solder ball mounting section 57 for mounting the solder ball 1 on the connection terminals of the package 12 coated with the flux 9; The detection unit 61 detects the position of the connection terminal of the package 12 positioned at the 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, and a pair of pulleys 17 are fixed to both ends of the shaft 16, respectively.
The belt 19 is stretched in parallel with the longitudinal direction of 5 (direction of arrow X). 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 arrow X direction. 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 includes a bearing (not shown) slidably fitted to the rail 32 and a nut (not shown) screwed with the ball screw 35. It moves along the rail 32 in the arrow Y direction (the front-back direction of the paper surface of FIG. 1). This slider 3
On the front of 7, the arrow X
A pair of rails 39 extending in the direction and forming a linear guide device.
Is fixed. 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. And this ball screw 4
One end of 1 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 and a nut (not shown) screwed into the ball screw 41,
By the operation of the motor 42, the motor 42 is moved in the arrow X direction along the rail 39. 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 constitute a linear guide device, are fixed. In addition, on the front surface of the slide plate 43, a rail 45 is provided so as to be positioned between the rails 45 via a bearing 46.
A ball screw 47 is rotatably supported in parallel 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 is provided with a bearing 51 slidably fitted to the rail 45 and a nut (not shown) screwed to the ball screw 47, and 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 any position in the X, Y, and Z directions by operating the motor 36, the motor 42, and the motor 49.

The flux supply section 51 comprises a flux supply means 52 supported by the base 11 and a flux supply jig 56 supported by the mount head 50.

The flux supply means 52 is provided with a flux container 53 having a flat surface formed therein, and a squeegee 55 for scraping and leveling the flux 9 supplied into the flux container 53. Then, the squeegee 55 is opposed to the flat surface of the flux container 53 at a predetermined interval and is moved in the direction of the arrow X to scrape and level the flux 9 supplied into the flux container 53, whereby the flux 9
To form a film.

The flux supply jig 56 has a plurality of pins (not shown) in the same arrangement as the arrangement of the connection terminals of the package 12.

The solder ball mounting portion 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 attracting and holding the solder balls 1.

The solder ball supply means 59 is arranged on the base 11 and, as shown in FIG. 2, a solder ball container 2 for accommodating a plurality of solder balls 1 and the solder ball 1 in the solder ball container 2. The piezoelectric vibrator 4 as a floating means for floating the and the drive power source 8 for the same. The piezoelectric vibrator 4 operates with a sinusoidal voltage signal applied from the driving power source 8 to generate a sinusoidal displacement vibration to vibrate the solder ball container 2 and float the contained solder ball 1. Let

As the floating means for floating the solder balls 1 in the solder ball container 2, the piezoelectric vibrator 4 is used.
Alternatively, compressed air may be ejected from the bottom surface of the solder ball container 2.

The alignment mask 7 is formed in a hollow box shape, and a plurality of suction holes 6 are formed on the suction surface in the same arrangement as the arrangement of the connection terminals of the package 12. The diameter of the suction hole 6 is the solder ball 1 to be mounted on the package 12.
Is smaller than the diameter of. Also, this alignment mask 7
Is connected to a vacuum supply source 5 by a pipe 3.

Therefore, the alignment mask 7 is arranged so as to cover the opening of the solder ball container 2, 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, the solder ball 1 floats from the bottom of the solder ball container 2 toward the suction surface of the alignment mask 7, and thus the floating solder ball 1 is attracted to the suction hole 6 by the flow of air sucked from the suction hole 6. Are held by adsorption.

As shown in FIG. 1, the detector 61 includes a ring light 62 mounted on the mount head 50,
A CCD camera 63 is provided. Then, the image captured by the CCD camera 63 is analyzed by an image processing device (not shown) to calculate the position of the connection terminal of the package 12.

Further, the solder ball mounting apparatus 10 is shown in FIG.
The measuring means as shown in FIG. The sensor 66 is, for example, a reflection-type light-shielding sensor that detects the reflected light of the solder ball 1 that crosses the projected light beam, and is attached to the solder ball container 2. The oscillator 67 oscillates a clock signal having a constant frequency (for example, 1 MHz).

The measuring means 68 has a counter 69 and a computing means 70. The counter 69 counts the clock signal oscillated from the oscillator 67 only while the sensor 66 receives the reflected light of the solder ball 1. And add up. The calculation means 70 calculates the number of solder balls 1 in the solder ball container 2 based on the number of clock signals counted by the counter 69.

The control means 71 controls the drive power source 8, the sensor 66, the oscillator 67 and the measuring means 68. Also,
When the number of the solder balls 1 measured by the measuring means 68 is less than the specified range, the solder ball container 2 is instructed to be replenished with the solder balls 1. When the number of solder balls 1 is larger than the specified range, an alarm is generated and the solder ball mounting device 10 is stopped.

With the above construction, the conductive ball mounting apparatus 10 operates the cylinder 22 when the carrier 21 having the package 12 mounted thereon is supplied 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, in the flux supply means 51, the squeegee 55 is moved to scrape and even the flux 9 in the flux container 53 to form a thin film of the flux 9.

In the drive unit 30, the motor 36, the motor 42
Also, the motor 49 is operated to move the mount head 50 in the X, Y, and Z directions, and the flux supply jig 56 is moved.
And the alignment mask 7 are inserted into the flux container 53 and the solder ball container 2, respectively. Then, the pins of the flux supply jig 56 penetrate into the thin film of the flux 9 formed in the flux container 53, and the required amount of 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 from the vacuum supply source 5 through the pipe 3. At the same time, in response to a command from the control means 71, the drive power source 8 is activated to vibrate the solder ball container 2 to float the solder balls 1 contained therein.

The oscillator 67 outputs a clock signal having a constant frequency as shown in FIG. 3A in response to a command from the control means 71. Further, the sensor 66 projects a light beam in accordance with a command from the control means 71, and FIG.
The detection signal that receives the reflected light from the floating solder ball 1 is output as shown in FIG. In FIG. 3B, A indicates a detection signal when the reflected light of one solder ball 1 is received, and B indicates a detection signal when the reflected light of a plurality of solder balls 1 is continuously received.

As shown in FIG. 3C, the counter 69 counts and integrates the number of clock signals applied from the oscillator 67 only while the sensor 66 outputs the detection signals A and B.

When the time required for sucking the solder balls 1 into all the preset suction holes of the alignment mask 7 has elapsed, the control means 71 stops the drive power supply 8, the sensor 66, and the oscillator 67. On the other hand, the arithmetic means 70 reads out the number of clock signals counted by the counter 69 and resets the counter 69.

The calculating means 70 calculates the total floating time, which is considered as the floating of the solder ball 1, from the count value (the number of clock signals) read from the counter 69, and FIG.
The number of solder balls 1 in the solder ball container 2 is obtained from the correlation between the floating time of the solder balls 1 and the number of solder balls 1 accommodated in the solder ball container 2 as shown in FIG.

There is a correlation as shown in FIG. 4 between the floating time of the solder balls 1 and the number of the solder balls 1, and by using the range in which there is a linear correlation, the solder balls are The number of solder balls 1 can be accurately calculated from the floating time of 1.

The control means 71 determines whether or not it is necessary to refill the solder balls 1 from the number of the solder balls 1 applied from the arithmetic means 70, and displays the result. That is, when the number of the solder balls 1 calculated by the arithmetic unit 70 is less than the lower limit of the specified range (the range in which non-adsorption or excess adsorption is least generated when the solder balls 1 are adsorbed by the alignment mask 7). When an instruction to replenish the solder balls 1 is output to the solder ball container 2 and the number of the solder balls 1 calculated by the calculation means 70 is larger than the specified range,
An alarm is oscillated to stop the solder ball mounting device 10.

The solder balls 1 can be supplied to the solder ball container 2 manually or by using a dedicated jig. When the number of solder balls 1 is large, the solder balls 1 in the solder ball container 2 are manually
Are excluded in an appropriate amount.

On the other hand, the motor 36 and the motor 4 of the drive unit 30
2 and the motor 49 actuate to move the mount head 50 in the X, Y, and Z directions, and move the CCD camera 63 to a position facing the package 12 at the mounting position.
Then, the ring light 62 is turned on, and the CCD camera 63
Take the package 12 with. The image analysis device extracts the image of the connection terminal from the captured image data, calculates the position of the image, and sends the calculation result to a control device (not shown).

The control device operates the motor 36 and the motor 42 of the drive unit 30 based on the position data of the connection terminals of the package 12 input from the image analysis device, and connects the pins of the flux supply jig 56 to the package 12. Move to a position facing the terminal. 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.

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 of the alignment mask 7 is released, and the solder balls 1 are released from the alignment mask 7. In this state, when the motor 49 operates to raise the mount head 50, 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. It

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.

The method of floating the solder balls 1 may be by jetting compressed air in addition to the above vibration. Also, the solder ball mounting device is shown in FIG.
As shown in, the flux and the solder balls may be transferred and mounted on the package, respectively, or the flux may be attached to the solder balls adsorbed by the alignment mask and mounted on the package.

[0056]

As described above, according to the present invention, when the solder balls are attracted by the alignment mask, the number of solder balls in the solder ball container is measured. Even if it is consumed, it is possible to always manage the number of solder balls in the solder ball container within the specified range (appropriate range), and it is possible to greatly reduce the occurrence of non-adsorption and excess adsorption. It is possible to greatly improve the sex.

[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 measuring unit according to the present invention.

FIG. 3 is a time chart showing the measuring method of the measuring means in FIG.

FIG. 4 is a characteristic diagram showing the correlation between the total floating time of solder balls and the number of solder balls.

FIG. 5 is a process drawing showing a solder ball suction process using an alignment mask.

FIG. 6 is a front view showing a suction state of solder balls by an alignment mask.

FIG. 7 is a front view showing a suction state of solder balls by an alignment mask.

[Explanation of symbols]

1 ... Conductive ball (solder ball) 2 ... Container (solder ball container) 4 Floating means (piezoelectric vibrator) 7 ... Alignment mask 10 ... Conductive ball mounting device (solder ball mounting device) 12 ... Package 25 ... Mounting part 59 ... Conductive ball supply unit (solder ball supply means) 66 ... Shading sensor 67 ... Oscillator 68 ... Measuring means 69 ... Counter 70 ... Calculation means 71 ... Control means

Claims (2)

[Claims] 1. A mounting portion for positioning a package having a plurality of connection terminals formed thereon, a conductive ball supply portion having a container for storing a plurality of conductive balls, and a package connected to a vacuum source and attached to the suction surface of the package. A plurality of suction holes are formed in the same arrangement as the plurality of connection terminals formed in, and the conductive balls are sucked and taken out from the conductive ball supply portion to the suction holes, and the package positioned in the mounting portion is connected. An alignment mask for mounting the conductive balls on the terminals, a measuring unit for measuring the number of the conductive balls in the container of the conductive ball supply unit, and the number of the conductive balls based on the measurement result by the measuring unit. When the number of conductive balls is less than the specified range, it instructs to refill the conductive balls in the container.When the number of the conductive balls is more than the specified range, an alarm is generated and the conductive balls are A control means for stopping the Le mounting device, and the provided, characterized in that, the conductive ball mounting apparatus. 2. The conductive ball supply unit comprises a floating means for floating the conductive balls in the container, and the measuring means traverses an oscillator for oscillating a clock signal of a constant frequency and a projected light beam. A reflection type light-shielding sensor for detecting the reflected light of the conductive ball, a counter for counting a clock signal oscillated from the oscillator while the light-shielding sensor receives the reflected light from the conductive ball, and the counter. The conductive ball mounting device according to claim 1, further comprising a calculation unit that calculates the number of conductive balls based on the count value of.