JP2014017328A - Mounting device and measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mounding device capable of performing measurement adjustment for obtaining a preferred mounting result even in mounting a large-sized chip.SOLUTION: A contact pin is buried in a surface of a substrate stage. A mounting part is lowered so that a nozzle suction surface is brought into contact with a tip of the contact pin, and a relative movement amount between the mounting part and a mounting unit in such a case is determined. A degree of parallelization between the substrate stage and the nozzle suction surface can be numerically obtained by determining the relative movement amount at a plurality points within the nozzle suction surface.

Description

  The present invention relates to a so-called electronic component mounting apparatus for mounting an electronic component on a circuit board and a measurement method performed in the apparatus. More specifically, the present invention relates to a mounting apparatus suitably used for mounting an IC chip called a flip chip having bumps (convex electrodes) on a circuit board, and a measurement method using the mounting apparatus.

  In recent years, with the miniaturization of electronic devices, it is required to mount electronic components on a circuit board at a higher density. In order to meet these demands, the positional accuracy during mounting has been increased, and at the same time, the interval between components (the pitch) has been promoted. Further, as a new form, an example in which an electronic component is mounted in a cavity provided in a multilayered substrate is increasing. The electronic component used here has a fine structure in order to have a high function, and is required to be suitably mounted on a circuit board without applying an excessive load.

  Patent Documents 1 to 3 disclose techniques for suppressing the addition of an excessive load in such an electronic component mounting process. A suitable joining state is obtained by causing sliding in the ultrasonic region between the bumps of the electronic component and the substrate electrode while applying an appropriate pressing load while avoiding an excessive load. In consideration of the case where a preferable bonding state cannot be obtained only by vibration in the ultrasonic region, Patent Documents 3 and 4 also disclose a technique for obtaining a preferable bonding by applying heat at the time of bonding. By appropriately applying these techniques, even electronic components having a precise and relatively fragile structure can be suitably bonded to a circuit board.

JP 2009-267277 A JP 2009-267238 A JP 2009-253256 A JP 2010-0050465 A JP 2009-033026 A

  2. Description of the Related Art In recent years, along with higher performance and higher functionality of electronic devices, various functions are also assigned to the electronic components to be mounted, so that even if the electronic components themselves become larger, the electronic device can be made smaller and more functional. An approach has been made. Along with this, in order to obtain the above-described preferred bump-electrode bonding state, all the bumps dispersed and arranged in a certain region or more are in contact with the electrode evenly and an equal load is applied. Is required. In recent years, electronic components having an optical function have been used, and the electronic components are bonded to a circuit board to which an optical waveguide or the like is added while maintaining high parallelism. It is hoped that

Conventionally, this is dealt with by measuring the mounting nozzle at a stage before the mounting process. As a specific method, for example, pressure-sensitive paper is arranged on the surface of the circuit board holding stage, and the parallelism is measured by pressing the suction surface of the mounting nozzle on this, and the mounting nozzle is adjusted based on the measurement result. Is going. However, such a measurement adjustment process requires a great deal of effort, and it is desired that the process can be simplified to ensure stable parallelism at the time of mounting.

  The present invention has been made in view of the above situation, and ensures high parallelism between an electronic component and a circuit board, and allows the mounting process to be performed while maintaining this. It is an object of the present invention to provide a mounting apparatus and a measurement method using the mounting apparatus.

In order to solve the above problems, a mounting apparatus according to the present invention is a mounting apparatus for mounting an electronic component on a circuit board, the mounting unit holding the electronic component on a holding plane and mounting the circuit board on the circuit board, and a mounting A mounting portion main body that supports the unit so as to be movable in a predetermined axial direction, a relative movement amount measuring means that can measure a relative movement amount of the mounting portion main body and the mounting unit in a predetermined axial direction, and a perpendicular to the predetermined axis. Relative movement amount measuring means comprising: a substrate stage that supports the circuit board on the surface and is movable in the surface; and a contact pin that is embedded in one of the substrate stage and the holding plane and protrudes toward the other. Is characterized by measuring a relative axial movement amount of the mounting unit main body and the mounting unit caused by contact of the contact pin with the other.
In the mounting apparatus, it is preferable that the tip of the contact pin has a curved surface protruding toward the other side. Moreover, in this apparatus, it is preferable that the other and the contact pin abut at a plurality of positions by the movement of the substrate stage. Further, it is more preferable that the relative movement amount measuring means detects the position of the electronic component to be mounted in a direction along a predetermined axis.

Further, in order to solve the above-described problem, the measurement method according to the present invention includes a mounting apparatus for mounting an electronic component on a circuit board, and a parallel holding plane for holding and mounting the electronic component and a substrate stage surface for supporting the circuit board. A mounting unit for holding an electronic component on a holding plane and mounting it on a circuit board, and a mounting unit body for supporting the mounting unit so as to be movable in a predetermined axial direction. A lowering step of lowering the mounting unit by a predetermined amount, and a relative movement step of relatively moving the mounting unit body and the mounting unit by bringing the other into contact with a contact pin protruding from one of the substrate stage surface and the holding plane toward the other. Obtained by a repeated calculation process, a calculation process for calculating a relatively moved amount, a descent process, a relative movement process, and a calculation process at a plurality of other positions. A comparison step of comparing the relative amount of movement, and having a.
In addition, this invention also includes the program which makes a control apparatus perform each process in the said measuring method.

According to the present invention, it is possible to easily and accurately execute measurement adjustment work for obtaining the parallelism of the mounting nozzle suction surface before the mounting process, and it is possible to stably perform the mounting process of large electronic components and the like. It becomes possible.

It is a figure which simplifies and shows the principal part structure in the mounting apparatus which concerns on one Embodiment of this invention. It is a figure which shows schematic structure of the mounting apparatus which concerns on one Embodiment of this invention. It is a figure which shows the outline of the structure in the axial cross section of the mounting part 50 used in one Embodiment of this invention. It is a figure which shows typically the relationship between the structure relevant to the mounting unit 57, and the substrate stage 11 regarding the measuring method of the nozzle parallelism which is one Embodiment of this invention. It is a figure which shows the example of the parallelism measurement point in the nozzle suction surface 51b. It is a figure which shows the measuring method of the nozzle parallelism which is one Embodiment of this invention as a flowchart. It is a figure which shows the structure for performing the measuring method by the mounting apparatus which concerns on one Embodiment of this invention as a functional block.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of a main part of a mounting apparatus according to the present invention, and FIG. 2 shows a simplified schematic configuration of the apparatus. As shown in FIG. 2, this apparatus includes a base plate table 10 that supports a circuit board, a component supply table 20 that supports electronic components, a component take-in unit 30 that supports a take-out nozzle, and a mounting unit 50 that supports a mounting nozzle. It consists of. In the following description, the electronic component is referred to as a chip according to the embodiment, and the circuit board is referred to as a substrate.

  The substrate table 10 includes a substrate stage 11 that actually supports the substrate by vacuum suction or the like, an X-axis drive motor 13 that drives the substrate stage 11 in the X direction indicated by an arrow in the figure, and a Y axis that drives the substrate stage 11 in the Y direction. A drive motor 15 and a component recognition camera 17 for recognizing the posture and the like of an electronic component held by a mounting nozzle described later are provided. In the present embodiment, the component recognition camera 17 is fixed to the substrate stage 11 and always has a fixed positional relationship with the substrate stage 11.

  The component supply table 20 includes a table 21 on which components are placed, a drive motor (not shown) that drives the table 21 in the XY direction, and a rotation drive motor 23 that rotates the table 21 on the XY plane. Yes. On the table 21, a component mounting substrate having a shape substantially equal to the shape of a wafer on which electronic components such as flip chips are spread is fixed by vacuum suction or the like. These electronic components are simply placed on a component mounting board, and can be easily taken out from the board.

  The component take-in unit 30 includes a take-out nozzle 33 that is rotatably supported by a rotary shaft 31 that is turned upside down, and a take-out nozzle elevating motor 35 that drives the rotary shaft 31 and the take-out nozzle 33 up and down. These are integrated as a capturing unit 39 and supported by a capturing unit base 37 so as to be driven in the X-axis direction by a drive motor (not shown). The component take-in unit 30 further includes a supply component recognition camera 41 and a pre-alignment camera 43, which are fixed and supported on the base 37 independently of the unit 39 including the take-out nozzle 33 and the like. ing.

  The pre-alignment camera 43 images the chip held by the take-out nozzle 33. The video thus obtained is subjected to image processing, and the amount of deviation from the reference position or reference posture when the chip is held is obtained. The deviation is obtained as the X direction, the Y direction, and the angle θ. These misregistration amounts are calculated by a control device (not shown), and the control device constitutes a misregistration amount detecting means together with the pre-alignment camera 43.

  The mounting unit 50 includes, for example, a mounting nozzle 51 having a function of mounting electronic components on a circuit board using ultrasonic waves, and θ for rotationally driving the mounting nozzle 51 about an axis perpendicular to the XY plane. The rotary motor 53 and the mounting nozzle raising / lowering motor 55 for raising and lowering the nozzle 51 and the motor 53 are provided. These are integrated as a mounting unit 57 and supported by a mounting portion base 59 so as to be driven in the Y-axis direction by a driving motor (not shown). Note that a substrate mark recognition camera 61 is fixed and supported on the mounting unit 57 independently of the mounting nozzle 51, the θ rotation motor 53, and the lifting motor 55.

  The driving of each component in the X-axis direction and the Y-axis direction described above is performed by a combination of a ball screw shaft and a guide rail directly connected to each driving motor. Therefore, the description regarding these structures is abbreviate | omitted here. Moreover, these structures are well-known, and it is desirable to change suitably with another well-known structure according to the required stop precision and drive speed. In this embodiment, the take-out nozzle moves in the X-axis direction and the mounting nozzle moves in the Y-axis direction. However, the take-out nozzle moves in the Y-axis direction and the mount nozzle moves in the X-axis direction. good.

  Here, the mounting unit 57 will be described in detail with reference to FIG. The mounting unit 57 includes an ultrasonic oscillator 67 and an ultrasonic horn 69 fixed to the ultrasonic oscillator 67. The mounting nozzle 51 is inserted and fixed in a hole 69 a formed in a vibration antinode (maximum amplitude portion) of the ultrasonic horn 69. The hole 69 a functions as a mounting nozzle fastening hole in the ultrasonic horn 69. Ultrasonic vibration is applied to an electronic component (not shown) adsorbed on the tip of the mounting nozzle 51 via an ultrasonic horn 69, and the electrodes of the electronic component and the substrate are joined by the ultrasonic vibration energy. In the ultrasonic horn 69, a vibration node (minimum vibration portion) is mechanically held by a clamp 501, and the clamp 501 is mechanically fastened to a shaft 503 having an axis in the Z direction. At this time, the shaft fastening hole 501a of the clamp 501 and the mounting nozzle fastening hole 69a of the ultrasonic horn 69 exist on the same axis, and the rotation θ of the shaft 503 and the rotation θ of the mounting nozzle 51 coincide.

  The shaft 503 is divided into a first shaft portion 503a having a polygonal cross section supported by the spline 505 in the Z direction and a second shaft portion 503b having a circular cross section supported by the slide rotary bush 507 in the θ direction. Is done. An outer cylinder of the spline 505 is supported by a bearing 509. Therefore, the shaft 505 can freely move in the Z-axis direction and rotate around the Z-axis. The spline 505 and the bearing 509 are located in the vicinity of the clamp 501 at the lower end in the Z-axis direction of the shaft 503.

  More specifically, the spline 505 and the bearing 509 are disposed closer to the clamp 501 than the voice coil motor 511 when viewed from the solenoid 513. By satisfy | filling the said arrangement | positioning, the mounting nozzle 51 can be hold | maintained with high rigidity. The movement of the shaft 503 in the Z direction is given by a voice coil motor 511, and this voice coil motor 511 gives a pressing force to the electronic component at the tip of the mounting nozzle 51. Accordingly, the shaft 503 is driven in the Z-axis direction by the voice coil motor 511. Further, the bearing case 515 connected to the solenoid 513 installed above the Z axis of the shaft 503 is brought into contact with the block 517, thereby preventing the shaft 503 from freely moving in the Z direction. That is, the movement of the shaft 503 in the Z-axis direction is restricted by the solenoid 513.

  The inertial mass of the shaft 503 cannot be held by the voice coil motor 511 described above. For this reason, when the entire mounting unit 57 is moved in the Z-axis direction, the shaft 503 moves in the mounting unit 57 due to inertia. In the present invention, in order to prevent this, the shaft 503 is held in a predetermined arrangement by the force of the solenoid 513. The θ direction operation of the shaft 503 is conducted to the outer cylinder of the spline 505 via the flange by the θ rotation motor 53 incorporating the speed reducer, and is transmitted to the first shaft portion 503a via the spline 505. In the present invention, as the spline 505, a rolling bearing or a sliding bearing (air slide) using compressed air as a lubricant can be used. By using an air slide that does not deteriorate over time, such as a load such as friction or a mechanical bearing, a stable sliding state can be obtained for a long period of time, and a high stopping system can be maintained.

  The mounting part body 50a in the mounting part 50 holds the mounting unit 57 slidably in the Z-axis direction via the voice coil motor 551 as described above. Further, a linear scale 521 is disposed between the mounting unit main body 50a and the mounting unit 57, and has a function of detecting the position of the chip to be mounted in the Z-axis direction, for example.

  In the present embodiment, contact pins are embedded at predetermined positions on the surface of the substrate stage 11 described above, and the positional relationship between the nozzle suction surface (see reference numeral 51b in FIG. 3) and the surface of the substrate stage 11 is obtained using them. I am going to do that. Details will be described with reference to FIG. 4 (a) and 4 (b) schematically show the relationship between the related configuration in the mounting unit 57 and the substrate stage 11, FIG. 4 (a) is before measurement, and FIG. 4 (b) is FIG. Each state during measurement is shown. The main body 50a of the mounting portion 50 holds the mounting unit 57 slidably in the Z-axis direction via the voice coil motor 511 as described above. Further, the linear scale 521 described above can measure the relative position change in the Z-axis direction.

  A contact pin 523 is embedded at a predetermined position on the surface of the substrate stage 11 so as to face the nozzle suction surface 51 b that contacts and holds the chip in the mounting nozzle 51. The top of the contact pin 523 has a spherical shape to stabilize the contact point and prevent damage to the nozzle suction surface 51b. The contact pin 523 functions as a reference jig for measuring the parallelism of the mounting nozzle suction surface 51. As described above, the substrate stage 11 is movable in the XY plane. Accordingly, by moving the substrate stage 11, the contact pin 523 can be made to correspond to various positions of the nozzle suction surface 51b. The tip of the contact pin 523 is preferably spherical for the reasons described above, but the material of the holding plane that is the nozzle suction surface 51b can be variously modified depending on the surface condition, the material of the contact pin, and the like. It is.

  As described above, in the present embodiment, in addition to the linear scale 521 and the substrate stage 11 that are already arranged in the mounting unit 50 of the mounting apparatus, it is desirable to simply embed the contact pins 523 in the substrate stage 11. Can be measured. Therefore, the present invention can be easily applied to a currently used apparatus or the like.

  Next, an actual parallelism measuring operation that is a measuring method of the mounting apparatus according to the embodiment of the present invention will be described. First, the substrate stage 11 is driven, and as shown in FIG. 4A, the measurement point on the nozzle suction surface 51b and the tip of the contact pin 523 are opposed and aligned in the Z-axis direction. Subsequently, the solenoid 513 is operated to lower the mounting unit 50 along the Z axis. When the descent continues until a predetermined amount is reached and the nozzle suction surface 51b and the tip of the contact pin 523 come into contact with each other, only the mounting unit 57 rises in the Z-axis direction. More specifically, the mounting unit 57 rises relatively along the Z-axis direction with respect to the mounting portion main body 50a. Since the linear scale 521 described above can measure the relative movement amount of the mounting unit main body 50a and the mounting unit 57, the rising of the mounting unit 57 is detected by the linear scale 521. By these operations, the height from the surface of the substrate stage 11 at the measurement position on the nozzle suction surface 51b of the suction nozzle 51 is obtained.

  In actual measurement of parallelism, the above height measurement is performed on a plurality of points in the suction surface 51b. A specific example of the height measurement position is shown in FIG. FIG. 5 schematically shows a state in which the nozzle suction surface 51b is viewed from below the Z axis, with the measurement points 1 to 4 at the four corners of the rectangular nozzle suction surface 51b with the suction port 51a disposed in the center as the center. Is arranged. For example, in the actual measurement, when the determination is performed with reference to the measurement point 1, the relative movement amount indicated by the linear scale 521 when the mounting unit 50 is lowered by a predetermined amount is set to the height reference 0 of the measurement point 1, and On the other hand, how many μm the relative movement amount of the measurement points 2 to 4 is shifted up and down is obtained. Furthermore, the shift variation for each obtained measurement point is obtained, and if this is larger than a predetermined threshold value, it is determined that the parallelism has not reached the desired value, and the adjustment may be performed.

  Hereinafter, a parallelism measurement method according to an embodiment of the present invention will be described with reference to FIG. When measuring the parallelism, first, the substrate stage 11 is driven in step S 1, and the above-described measurement point 1 is arranged immediately above the contact pin 523. Next, the mounting unit 50 is lowered by a predetermined amount (step S2), and the height of the measurement point 1 is obtained from the linear scale 521 by the above-described operation. After calculating the height, in step S4, it is determined how many times the measurement is performed. In this case, since the measurement of the measurement points 2 to 4 has not been performed yet, the flow returns to step S1 again to measure the height of the measurement point 2. Thereafter, this operation is repeated n times corresponding to the number of measurement points. When the measurement is completed for all points, the flow proceeds to step S5, and the reference height is set from these measurement points.

  After the reference height is set, in step S6, the height variation of each measurement point with respect to the reference height is calculated. This variation is compared with a threshold value in step S7, and if it is smaller than the threshold value, the measurement process is terminated, assuming that parallelism without any problem is secured even if the actual mounting process is performed. If the variation is equal to or greater than the threshold value, it is determined that the device is in an unsuitable state for performing the mounting process as it is, an alarm such as a buzzer is issued in step S8, and then the measurement process is terminated. By performing the above operation, the operator of the mounting apparatus can easily and quickly confirm the parallelism of the suction nozzle based on specific numerical values. In addition, since it is possible to know the degree of variation at each measurement point, even if adjustment is necessary, it is possible to make adjustments based on numerical values. Becomes easy.

  In the above-described embodiment, the measurement of the relative movement amount between the mounting unit main body 50a and the mounting unit 57 is performed by the linear scale 521. However, the embodiment of the present invention is not limited to this, and other various modes such as various other contact sensors and optical sensors can be applied as long as the amount of movement relative to the contact can be measured. It is. Therefore, the configuration is preferably grasped as a relative movement amount measuring unit capable of measuring the relative movement amount of the mounting unit main body 50a and the mounting unit 57 in the predetermined axis (Z-axis) direction. Moreover, although the tip shape of the contact pin 523 is spherical, it suffices if a portion protruding toward the nozzle suction surface is disposed and the portion is configured by a curved surface. The measurement result of the variation may be mapped and displayed as an image on a monitor. Further, the suction surface for holding the chip is a holding plane, but it is not necessary to be a front plane, and the flatness of the holding surface is flat with the circuit board holding surface where the chip holding surface is flat and the region of the holding plane can be placed on the substrate stage 11. It only has to be secured. Further, in the above-described embodiment, the contact pin 523 is arranged on the substrate stage 11 side. However, the contact pin 523 may be embedded in the holding plane. Accordingly, the contact pin is preferably defined as a contact pin that is embedded in one of the substrate stage and the holding plane and protrudes toward the other, and measuring the relative movement amount by contacting the other. It is preferred that

  Next, a functional configuration for executing the above-described flow will be described. FIG. 7 is a block diagram illustrating a control unit that executes a flow based on a functional configuration. A control device 600 that controls the mounting device includes a control unit 605, a storage unit 607, a processing unit 610, and an output unit 609. The control unit 605 is connected to the above-described relative movement amount measuring unit 620 (linear scale 521) and the instruction input unit 630. The instruction input unit 630 is used, for example, for setting the number of measurement points and their positions, the above-described threshold value, or the display mode in the display unit 640 that executes the above-described monitor display. Further, data input from these components and various numerical values calculated by the processing unit 610 described later are stored in the storage unit 607.

  The relative movement amount sent from the control unit 605 to the processing unit 610 is processed by the reference value setting unit 611 and the variation amount calculation unit 113 arranged in the processing unit 610. The reference value setting unit 611 obtains the average value of the plurality of relative movement amounts described above, for example, and sets the reference height by a deviation based on the average value. The variation amount calculation unit 113 is set and calculates the variation amount at each point based on the reference height. The control unit 605 sends the calculated variation amount or a comparison result between the variation amount and the threshold value to the output unit 609. The output unit 609 performs an operation instruction of the alarm 650 or a display instruction of the variation amount on the display unit 640 according to the comparison result with the threshold value.

  By using the mounting device configured as described above, the parallelism between the nozzle suction surface and the surface of the substrate stage is always maintained with high accuracy even when mounting large-sized chips and chips including optical elements. The result can be obtained. The present invention also configures software (program) that implements the functions of the above-described embodiments, and supplies the system or apparatus to the system or apparatus via a network or various storage media. The system or apparatus computer (or CPU, MPU, etc.) ) Includes reading and executing a program.

2: chip, 10: substrate table unit, 11: substrate stage, 13: X-axis drive motor, 15: Y-axis drive motor, 17: component recognition camera, 20: component supply table, 21: table, 23: for rotation drive Motor: 30: parts take-in part, 31: rotary shaft, 33: take-out nozzle, 35: motor for raising / lowering nozzle, 37: take-in part base, 39: take-in part unit, 41: camera for recognizing supply parts, 43: pre-alignment Camera: 50: Mounting portion, 50a: Mounting portion main body 51: Mounting nozzle, 51a: Through-hole suction port, 51b: Nozzle suction surface, 53: θ rotation motor, 55: Nozzle lifting motor, 57: Mounting unit, 59: Mounting base, 61: Camera for substrate mark recognition, 501: Clamp, 503: Shaft, 503a: first shaft portion, 503b: second shaft portion, 505: spline, 511: voice coil motor, 513: solenoid, 517: block, 521: linear scale, 523: contact pin, 600: control device, 605 : Control unit, 607: storage unit, 609: output unit, 610: processing unit, 611: reference value setting unit, 613: variation amount calculation unit, 620: relative movement amount measuring means, 630: instruction input unit, 640: display Means, 650: Alarm

Claims (6)

A mounting device for mounting electronic components on a circuit board,
A mounting unit for holding the electronic component on a holding plane and mounting the electronic component on the circuit board;
A mounting portion main body that supports the mounting unit so as to be movable in a predetermined axial direction;
A relative movement amount measuring means capable of measuring a relative movement amount of the mounting unit main body and the mounting unit in the predetermined axial direction;
A substrate stage that supports the circuit board in a plane perpendicular to the predetermined axis and is movable in the plane;
A contact pin embedded in one of the substrate stage and the holding plane and projecting toward the other,
The relative movement amount measuring means measures a relative movement amount in the predetermined axial direction between the mounting portion main body and the mounting unit, which is generated when the contact pin comes into contact with the other.   The mounting device according to claim 1, wherein a tip end of the contact pin is a curved surface protruding toward the other side.   The mounting apparatus according to claim 1, wherein the other and the contact pins abut at a plurality of positions by the movement of the substrate stage.   The mounting apparatus according to claim 1, wherein the relative movement amount measuring unit detects a position of the electronic component to be mounted in a direction along the predetermined axis. In a mounting apparatus for mounting an electronic component on a circuit board, the electronic component is held and mounted, and a method for measuring parallelism between a holding plane for mounting and a substrate stage surface for supporting the circuit board,
A mounting unit that holds the electronic component on a holding plane and mounts it on the circuit board, and a mounting unit main body that supports the mounting unit so as to be movable in a predetermined axial direction, toward the surface of the substrate stage. A descent process to lower,
A relative movement step of relatively moving the mounting unit body and the mounting unit by bringing the other into contact with a contact pin protruding from one of the substrate stage surface and the holding plane toward the other;
A calculation step for calculating the amount of relative movement;
Performing the descent process, the relative movement process, and the calculation process at a plurality of positions of the other,
And a comparison step of comparing the relative movement amounts obtained by the repeated calculation steps.   The program which makes a control apparatus perform each process in the measuring method of Claim 5.

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