JP2012156329A - Part mounting method and part mounting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a part mounting method and a part mounting device that can perform accurate measurement with a simple construction.SOLUTION: According to a part mounting method, under the state that an electronic part 14 and a circuit board 17 are not held, a pointing head 11 is pressed against a stage 30 by a mounting load thereof from the state that the pointing head 11 is brought into contact with the stage 30, thereby measuring the stage deflection amount of the stage 30. The pointing head 11 approaches the stage 30 under the state that the electronic part 14 and the circuit board 17 are held, and a first position of the pointing head 11 at which the electronic part 14 is brought into contact with the circuit board 17 is measured. The electronic part 14 is pressed against the circuit board 17 by a mounting load thereof and mounted thereon, and a second position of the pointing head 11 is measured under the state that the mounting load is kept after the mounting. The amount of deformation of each bump is calculated on the basis of the stage deflection amount, the first position and the second position.

Description

  The present invention relates to a component mounting method and a component mounting apparatus for mounting an electronic component such as a semiconductor chip on a substrate.

Conventionally, when switching from load control to position control, a component mounting method and a component mounting apparatus for reducing a pressing load by an elevating pressing mechanism at a retroactive timing according to a response delay caused by a control switching operation of a mounting tool have been provided. It is known (see, for example, Patent Document 1).
In the component mounting method and the component mounting apparatus described in Patent Document 1, when mounting an electronic component on a circuit board, the circuit board is placed on a stage and the bonding head holds the electronic component.

Moreover, the component mounting method and component mounting apparatus described in Patent Document 1 bring the bonding head close to the stage.
Then, the component mounting method and component mounting apparatus described in Patent Document 1 contact the bumps provided on the circuit board with the pads formed on the circuit board, and then continue until the bumps are deformed into a barrel shape. Pressing is performed using sound waves in combination.

Japanese Patent Laying-Open No. 2005-236173 (FIG. 4, paragraph 0029)

In conventional component mounting equipment, bump deformation is not measured directly, but only the height of the bonding head is measured, and the bump is deformed to a desired shape when the bonding head reaches a predetermined height. Is common.
However, in recent years, bumps that have been subjected to plating have been frequently used. Since such bumps are made of a hard material, the pressing force required for deformation is larger than in the prior art.

For this reason, when pressing bumps that have been plated, the deflection of the stage that supports the circuit board affects the height position of the bonding head, making accurate measurement impossible, and poor bump connection to the circuit board. May occur.
As described above, since Patent Document 1 does not consider the amount of bending of the stage, for example, when the amount of deformation of the bump is about 2 to 3 μm and the amount of bending of the stage is about 5 μm, the amount of bending of the bump is included in the amount of bending of the stage. The amount of deformation is buried.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a component mounting method and a component mounting apparatus that can accurately measure the deformation amount of a bump with a simple configuration.

  In the component mounting method according to the present invention, an electronic component having a plurality of bumps on one side of a plate-like main body is held on a bonding head, and a circuit board is held on a stage so that a plurality of pads face each bump. The electronic component is brought close to the circuit board with a mounting load of the bonding head until the bumps and the pads are brought into contact with each other until the bumps are deformed into a predetermined shape. Is mounted on the circuit board by pressing with the mounting load from a state in which the bonding head is in contact with the stage in a state in which the electronic component and the circuit board are not held in advance. A deflection amount measuring step for measuring a stage deflection amount of the stage is performed, and then the electronic The first position of the bonding head when the electronic component is brought into contact with the circuit board is measured by bringing the bonding head close to the stage while holding the product and the circuit board. Performing a first position measuring step, and subsequently performing a mounting step of pressing the electronic component against the circuit board by the mounting load, and maintaining the mounting load after completion of the mounting step. A second position measurement step of measuring a second position of the head is performed, and a bump deformation amount calculation step of calculating a deformation amount of each bump from the stage deflection amount, the first position, and the second position is performed.

  A component mounting apparatus according to the present invention includes a bonding head that holds an electronic component having a plurality of bumps on one side of a plate-like main body, and a stage that holds a circuit board so that a plurality of pads face each of the bumps. The electronic component is brought close to the circuit board with a mounting load of the bonding head until each bump and each pad are brought into contact with each other until the bump is deformed into a predetermined shape. A component mounting apparatus for mounting a component on the circuit board by pressing the bonding head from the state in which the bonding head is in contact with the stage in a state where the electronic component and the circuit board are not held. A deflection amount measuring step for measuring a stage deflection amount of the stage; and the electronic component and the circuit board. A first position measuring step of measuring a first position of the bonding head when the electronic component is brought into contact with the circuit board by bringing the bonding head close to the stage while being held And a mounting step of pressing the electronic component against the circuit board by the mounting load, and a second position of the bonding head measured with the mounting load maintained after the mounting step is completed. A position measuring step, and a bump deformation amount calculating step of calculating a deformation amount of each bump from the stage deflection amount, the first position, and the second position.

  According to the component mounting method and the component mounting apparatus of the present invention, there is an effect that the deformation amount of the bump can be accurately measured with a simple configuration.

1 is an overall perspective view of a component mounting apparatus according to an embodiment of the present invention. The side view of the front | former stage of the bending amount measurement process of the component mounting method of one Embodiment which concerns on this invention The side view of the back | latter stage of the deflection amount measurement process of the component mounting method of one Embodiment which concerns on this invention Table used for component mounting method according to one embodiment of the present invention Timing chart for explaining the relationship between the bonding head and the load in the component mounting method according to an embodiment of the present invention The side view of the 1st position measurement process of the component mounting method of one embodiment concerning the present invention. The side view of the mounting process of the component mounting method of one Embodiment concerning this invention The side view of the 2nd position measurement process of the component mounting method of one embodiment concerning the present invention.

Hereinafter, a component mounting method and a component mounting apparatus according to an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, a component mounting apparatus 10 that executes a component mounting method according to an embodiment of the present invention includes a semiconductor chip 14 (FIG. 1) that is an electronic component having a plurality of bumps 13 on one side of a plate-like body 12. 3) is provided.
In addition, the component mounting apparatus 10 includes a board holding unit 15 that holds the circuit board 17 so that the plurality of pads 16 face each bump 13.

Then, the component mounting apparatus 10 mounts the bonding head 11 on the stage 30 constituting the substrate holding unit 15 until the bumps 13 and the pads 16 are brought into contact with each other until the bumps 13 are deformed into a predetermined shape. The semiconductor chip 14 is mounted on the circuit board 17 by pressing with the circuit board 17.
Further, the component mounting apparatus 10 measures the amount of stage deflection of the stage 30 by bringing the bonding head 11 into contact with the stage 30 and pressing it with a mounting load without holding the semiconductor chip 14 and the circuit board 17. A deflection amount measuring step is provided.

Furthermore, the component mounting apparatus 10 brings the bonding head 11 close to the stage 30 while holding the semiconductor chip 14 and the circuit board 17 respectively.
Then, the component mounting apparatus 10 includes a first position measuring step for measuring the first position of the bonding head 11 when the semiconductor chip 14 is brought into contact with the circuit board 17.
In addition, the component mounting apparatus 10 measures the second position of the bonding head 11 while maintaining the mounting load after the mounting process in which the semiconductor chip 14 is pressed against the circuit board 17 by the mounting load. And a second position measuring step.
In addition, the component mounting apparatus 10 includes a bump deformation amount calculation step of calculating the deformation amount of each bump 13 from the stage deflection amount, the first position, and the second position.

As shown in FIG. 1, in the component mounting apparatus 10, a component supply stage 19, a unit assembly stage 20, and a board holding unit 15 are arranged on a base 18 in the Y direction.
A wafer holding table 21 provided in the component supply stage 19 holds a semiconductor wafer 22 on which a plurality of semiconductor chips 14 that are electronic components to be mounted are arranged.
The unit assembly stage 20 collects functional units such as a tool stocker 25, a parts collection unit 26, a calibration reference mark 27, a relay stage 28, and an under camera 29 on a moving table 24 that reciprocates in the X direction by a linear motion mechanism 23. It has the composition arranged in.
The substrate holding unit 15 is configured such that the stage 30 that holds the circuit board 17 is horizontally driven by the XY table mechanism 31, and the semiconductor chip 14 is mounted on the circuit board 17.
A pickup head 32 that moves in the Y direction and advances and retreats in the X direction is provided between the part supply stage 19 and the unit assembly stage 20.

Above the component supply stage 19, the unit assembly stage 20, and the board holding unit 15, a Y-axis frame 33 positioned at the end of the base 18 in the X direction is supported at both ends by support posts 34. It is erected in the direction.
On the front surface of the Y-axis frame 33, a head moving mechanism 36 for incorporating and driving the first head 35 in the Y direction by linear motor driving is incorporated.
A mounting unit 37 having a function of holding the semiconductor chip 14 and mounting it on the circuit board 17 is mounted on the first head 35. The mounting unit 37 has a bonding head 11.

A first camera 38 and a second camera 39 are disposed above the component supply stage 19, the relay stage 28, and the board holding unit 15 for position recognition.
The first camera 38 images the semiconductor chip 14 to be taken out at the component supply stage 19.
The second camera 39 images the semiconductor chip 14 taken out from the component supply stage 19 and temporarily placed on the relay stage 28 for position correction.

The under camera 29 arranged on the unit assembly stage 20 images the semiconductor chip 14 taken out from the component supply stage 19 from below.
The semiconductor wafer 22 has a configuration in which a plurality of semiconductor chips 14 are bonded to a wafer sheet 40 in a predetermined arrangement. A plurality of semiconductor chips 14 in a state of being divided into individual pieces in a face-up posture with the active surface facing upward are adhered and held on the wafer sheet 40.

In the component removal operation, the component mounting apparatus 10 drives the XY table mechanism 31 to move the wafer sheet 40 horizontally in the XY directions.
Thereby, the component mounting apparatus 10 positions a desired semiconductor chip 14 to be taken out of the plurality of semiconductor chips 14 attached to the wafer sheet 40 at the pickup work position.

A pickup head 32 that adsorbs and holds the semiconductor chip 14 is disposed above the component supply stage 19.
The pickup head 32 is held by a pickup arm 41, and the pickup arm 41 extends above the component supply stage 19 from a pickup head moving mechanism 42 that is suspended from the lower surface of the Y-axis frame 33. Is provided.
When the pickup head moving mechanism 42 is driven, the pickup arm 41 moves in the X, Y, and Z directions and rotates about the X direction axis.

As a result, the pickup head 32 moves in the Y direction between the upper part of the component supply stage 19 and the upper part of the unit assembly stage 20 and advances and retreats in the X direction.
Therefore, the pickup head 32 performs an operation of picking up the semiconductor chip 14 from the component supply stage 19 and transferring it to the relay stage 28 provided in the unit assembly stage 20.
Further, when necessary, the pickup head 32 can be retracted in the X direction from above the pickup work position.
Then, the pickup arm 41 can reverse the pickup head 32 by rotating to reverse the posture of the semiconductor chip 14.

The component collection unit 26 has a function of discarding and collecting components that are determined to be unsuitable for mounting on the circuit board 17 such as defective components or mixed different components after being taken out from the component supply stage 19.
The calibration reference mark 27 is a reference mark provided to calibrate a mechanical position error caused by thermal expansion and contraction by imaging with a second camera 39 disposed above.
The relay stage 28 is disposed between the component supply stage 19 and the substrate holding unit 15 and is provided integrally with the tool stocker 25.
On the relay stage 28, the semiconductor chip 14 taken out from the component supply stage 19 by the pickup head 32 is placed for position correction.

The substrate holding unit 15 has a configuration in which a stage 30 for holding the circuit board 17 is provided on the XY table mechanism 31.
A mounting work position for mounting the semiconductor chip 14 on the circuit board 17 held on the stage 30 is set in the substrate holding unit 15, and the second camera 39 is arranged corresponding to the mounting work position. .
When the XY table mechanism 31 is driven, the stage 30 is moved horizontally in the XY direction together with the circuit board 17, and any component mounting point set on the circuit board 17 can be positioned at the mounting work position.

The first head 35 is guided in the Y direction by two guide rails 43 on the front surface of the head moving mechanism 36 provided on the Y-axis frame 33.
A rack 44 constituting a linear motor for driving the first head 35 in the Y direction is disposed between the guide rails 43.

The mounting unit 37 has a function of holding the semiconductor chip 14 that is a component to be mounted, and the first head 35 is moved horizontally in the Y direction and moved up and down.
The mounting unit 37 mounts the semiconductor chip 14 supplied from the component supply stage 19 on the circuit board 17 held on the stage 30.
At this time, there are the following three forms of mounting by the first head 35 to which the mounting unit 37 is mounted, and each can be selectively executed.

The first form is a pre-center mounting form in which the semiconductor chip 14 taken out from the component supply stage 19 by the pickup head 32 and placed on the relay stage 28 is held by the mounting unit 37 and mounted on the circuit board 17.
The second form is a direct mounting form in which the semiconductor chip 14 of the component supply stage 19 is directly held by the mounting unit 37 and mounted on the circuit board 17.
The third mode is a face-down mounting mode in which the semiconductor chip 14 taken out from the component supply stage 19 by the pickup head 32 and held on the pickup head 32 in a reversed state is held by the mounting unit 37 and mounted on the circuit board 17. It is.

As shown in FIG. 2, in the component mounting method, the bonding head 11 is pressed against the stage 30 without holding the semiconductor chip 14 and the circuit board 17 in advance before the deflection amount measuring step. The height H1 is measured.
As shown in FIG. 3, in the component mounting method, the stage 30 bends due to the pressing of the bonding head 11 against the stage 30 in the subsequent stage of the deflection amount measuring step, and the height H2 and the height H1 of the bonding head 11 associated therewith. Measure the deviation.

As shown in FIG. 4, the component mounting apparatus 10 presses the bonding head 11 against the stage 30 without holding the semiconductor chip 14 and the circuit board 17 in advance.
Thereby, the component mounting apparatus 10 stores the table 50 created based on the measurement of the stage deflection amount of the stage 30.
In this table 50, the stage deflection amount of the stage 30 is set in a step shape according to the load value of the bonding head 11 with respect to the stage 30.
In FIG. 4, the solid line indicating the height position of the bonding head 11 is an actual measurement value.

As shown in FIG. 5, the component mounting apparatus 10 brings the bonding head 11 close to the stage 30 while holding the semiconductor chip 14 and the circuit board 17 at time T ₁ .
Then, the component mounting apparatus 10 executes a first position measuring step of measuring the first position (see FIG. 6) A1 of the bonding head 11 when the semiconductor chip 14 is brought into contact with the circuit board 17.

Next, the component mounting apparatus 10 executes a mounting process of pressing the semiconductor chip 14 against the circuit board 17 by increasing the mounting load stepwise or continuously between the time T ₂ and the time T _4. To do.
As a result, as shown in FIG. 8, each bump 13 is deformed into a bowl shape and is crimped to each pad 16, and the stage 30 is bent.
The component mounting apparatus 10, after the mounting step is completed, a second position measuring for measuring a second position A2 of the bonding head 11 in a state maintaining the mounting load of the bonding head 11 relative to the stage 30 (time T ₅₎ Execute the process.

Subsequently, a bump deformation amount calculating step of calculating the deformation amount of each bump 13 from the stage deflection amount obtained from the table 50 and the first position A1 and the second position A2 of the bonding head 11 is executed.
Specifically, the stage deflection amount corresponding to the mounting load is further subtracted from the difference between the first position A1 and the second position A2 of the bonding head 11.
That is, in this bump deformation amount calculation step, since the stage deflection amount corresponding to the mounting load is subtracted from the difference between the first position A1 and the second position A2 of the bonding head 11, the actual deformation amount of each bump 13 is determined. Calculated accurately.
The correction value shown in FIG. 5 is obtained by subtracting the stage deflection amount from the actual measurement value.

  As described above, according to the component mounting method and the component mounting apparatus 10 of the embodiment, accurate measurement can be performed with a simple configuration.

  In the above-described embodiment, the bump deformation amount calculation process is performed in a state where the mounting load of the bonding head 11 with respect to the stage 30 is maintained after the mounting process is completed. However, the bump deformation amount calculation process is performed in the middle of the mounting process. It may be performed at any time or one by one.

For example, if any of the bumps 13 is defective in advance, for example, if the initial height dimension is less than the allowable dimension, if the initial height dimension of each bump 13 is more than the allowable range, In the case where any of 13 is missing, the circuit board 17 is warped in an allowable range, or the equipment side is warped, the bonding at the time T ₁ is performed in the mounting process described above. The height position of the head 11 may become extremely downward.
In these cases, since a large deviation occurs between the actual measurement value and the stage deflection amount stored in the table 50 between the time point T ₁ and the time point T ₄ , the defective product is identified during the mounting process. it can. Even when bumps, electronic components, circuit boards, and the like are non-defective products, it can be similarly determined if they are crushed during the mounting process.
In such a bump deformation amount calculating process, since defective products and equipment defects can be determined before the mounting process is completed, the process time can be shortened.

  In the component mounting method and component mounting apparatus of the present invention, the component supply stage, unit assembly stage, and the like are not limited to the above-described embodiment, and appropriate modifications and improvements can be made.

As described above, according to the component mounting method and the component mounting apparatus of the present invention, accurate measurement can be performed with a simple configuration.
As a result, it is possible to provide high-quality electronic components and improve productivity, and the industrial applicability of the present invention can be said to be great.

DESCRIPTION OF SYMBOLS 10 Component mounting apparatus 11 Bonding head 12 Main body 13 Bump 14 Semiconductor chip (electronic component)
30 stages 16 pads 17 circuit boards

Claims (2)

While holding the electronic component having a plurality of bumps on one side of the plate-shaped main body on the bonding head, the circuit board is held on the stage so that each of the bumps faces each of the bumps,
The electronic component is brought close to the circuit board by a mounting load of the bonding head until the bumps and the pads are brought into contact with each other until the bumps are deformed into a predetermined shape. A component mounting method for mounting on a circuit board,
A deflection amount measuring step of measuring a stage deflection amount of the stage by pressing with the mounting load from a state where the bonding head is in contact with the stage in a state where the electronic component and the circuit board are not held in advance. Done
Next, when the electronic component is brought into contact with the circuit board by bringing the bonding head close to the stage while holding the electronic component and the circuit board, Performing a first position measuring step for measuring one position;
Subsequently, performing a mounting step of pressing the electronic component against the circuit board by the mounting load,
Performing a second position measuring step of measuring the second position of the bonding head in a state where the mounting load is maintained after completion of the mounting step;
A component mounting method for performing a bump deformation amount calculating step of calculating a deformation amount of each bump from the stage bending amount, the first position, and the second position. A bonding head for holding an electronic component having a plurality of bumps on one side of a plate-shaped main body;
A stage for holding the circuit board so that a plurality of pads face each bump,
The electronic component is brought close to the circuit board by a mounting load of the bonding head until the bumps and the pads are brought into contact with each other until the bumps are deformed into a predetermined shape. A component mounting apparatus for mounting on a circuit board,
In a state where the electronic component and the circuit board are not held, a deflection amount measuring step of measuring a stage deflection amount of the stage by pressing with the mounting load from a state where the bonding head is in contact with the stage;
A first position of the bonding head when the electronic component is brought into contact with the circuit board by bringing the bonding head close to the stage while holding the electronic component and the circuit board. A first position measuring step for measuring;
A mounting step of pressing the electronic component against the circuit board by the mounting load;
A second position measuring step of measuring the second position of the bonding head in a state where the mounting load is maintained after the mounting step is completed;
A component mounting apparatus comprising: a bump deformation amount calculating step of calculating a deformation amount of each bump from the stage bending amount, the first position, and the second position.

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