JP2009194015A - Workpiece mounting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a workpiece mounting apparatus capable of high-speed and high-precision output power in a wide load area ranging from low load to high load to obtain fine pressure bonding quality. <P>SOLUTION: The workpiece mounting apparatus includes a pressure bonding tool 5 that presses a workpiece 10, and first and second press means 1 and 2 that give the pressure bonding tool 5 a load for pressing the workpiece 10. The first press means 1 is composed of an air actuator that gives the pressure bonding tool 5 a load based on an instruction value. The second press means 2 is composed of a linear motor that gives a load that corrects an output load difference by the first press means 1 from the instruction value. The first and second press means 1 and 2 apply a load needed for workpiece mounting, to the workpiece 10. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a workpiece mounting apparatus that mounts a workpiece such as an electronic component by pressing it against a substrate or the like.

  When bonding an electronic component (work) to a substrate, a pressing force is applied to a crimping tool for pressing the electronic component, and the electronic component is pressed and bonded to the substrate. As means for pressing the crimping tool, there is one that employs an air actuator (Patent Document 1). That is, in the semiconductor chip mounting apparatus described in Patent Document 1, air of a predetermined pressure supplied to the air cylinder serves as a driving force, presses the crimping tool with this driving force, and directs the electronic component toward the substrate. And pressurizing and mounting. In this case, the load applied to the crimping tool is controlled by controlling the air pressure using a regulator.

  Moreover, as means for pressing the crimping tool, there is one that employs a linear motor such as a voice coil motor (Patent Document 2). That is, a voice coil motor is used as a drive source for the vertical movement of the crimping tool, and an electric current is passed through the coil wound around the crimping tool to move the crimping tool up and down. In this case, the load applied to the crimping tool is controlled by controlling the current flowing through the coil.

By the way, when an electronic component is mounted on a substrate by pressure bonding, it is necessary to obtain good pressure bonding quality. In order to prevent the substrate from cracking or chipping, it is necessary to reduce the load as much as possible when the electronic component contacts the substrate or the like. In addition, in order to obtain a good solder bonding state, an appropriate load profile that does not cause solder bonding failure is set in advance in the process of bonding the electronic component and the substrate, and the pressing force is highly accurate according to this load profile. Need to control.
JP 2007-287792 A JP 2002-281728 A

  Since the upper limit of the air pressure is determined in the air actuator as described in Patent Document 1, it is necessary to determine the upper limit of the output load by increasing the pressure receiving area or the like when applying a large output load. However, in this case, since the resolution of the regulator used for air pressure control is constant, when the output load is increased, the load resolution is lowered and it becomes difficult to output in the low load region. Further, the larger the load is output, the more the error from the preset load value increases due to the decrease in load resolution.

  In the case of controlling a linear motor, the thrust can be increased by increasing the current value. However, if the current value is increased too much, the coil generates heat and the crimping tool is heated, and this heating causes expansion. This causes a problem of breaking the electronic component. In addition, since the amount of current that can be passed through the coil is determined, when further increasing the load, it is necessary to increase the size of the linear motor, and it is also necessary to increase the device size. However, when the size of the device is increased, a large installation space is required. Furthermore, since the weight of the crimping tool increases, the impact load increases, resulting in a problem that a low load cannot be output. In addition, there is a possibility that the vibration becomes large due to the increase of inertia due to the high speed movement of the crimping tool, and the electronic component is broken by this vibration.

  As described above, in this type of conventional device, when the output load is increased, the load constituted by the air actuator is reduced, so that it is difficult to output in the low load region because the load resolution is reduced. In the case of the above, it is difficult to output in a low load region due to an increase in the weight of the crimping tool which is a movable part. For this reason, the pressing force of the crimping tool cannot be controlled in accordance with a preset load value in a wide range of loads from a low load to a high load, and good crimping quality cannot be obtained.

  In view of the above-described problems, the present invention provides a workpiece mounting apparatus that can output at high speed and high accuracy in a wide range of load from low load to high load, and can obtain good pressure bonding quality.

  The workpiece mounting apparatus according to the present invention is a workpiece mounting apparatus including a crimping tool that presses a workpiece and first and second pressing means that apply a load for pressing the workpiece to the crimping tool. The pressing means is composed of an air actuator that applies a load based on a command value to the crimping tool, and the second pressing means is a linear that applies a load that corrects a difference in output load by the first pressing means from the command value. It is comprised by a type | mold motor, and applies the set load which is a load required at the time of mounting to a workpiece | work by the said 1st, 2nd press means.

  According to the workpiece mounting apparatus of the present invention, since the two types of pressing means of the air actuator and the linear motor are provided, the difference in the output load by the first pressing means is corrected by the second pressing means from the command value. can do. In this case, the linear motor can adjust the thrust by adjusting the current flowing through the coil, so that errors caused by the air actuator can be corrected, and the load required for mounting can be applied to the workpiece with high accuracy. can do. Furthermore, since the linear motor has a faster response than the air actuator, the output load can be corrected at high speed.

  The linear motor can be a linear motor or a linear actuator. The linear motor is a drive device that gives a linear motion (reciprocating motion) directly to an object by electromagnetic force. The linear actuator is not a linear rotary motor developed linearly, but has a unique electromagnetic configuration and is different from a linear motor.

  The first pressing means and the second pressing means can be disposed on the axis of the crimping tool.

  The first pressing means can be disposed on the opposite side of the second pressing means.

  The load detector that detects the load applied to the workpiece, the load information detected by the load detector, and the set load are detected to detect excess and deficiency, and the second pressing means is controlled based on this excess and deficiency. And a control means for correcting the set load.

  In the present invention, the error between the load by the first pressing means based on the command value and the set load can be corrected by the second pressing means. For this reason, even if the error with the set load is large, the error can be corrected, and a highly accurate output is not required for the air actuator. Therefore, this workpiece mounting apparatus can output with high accuracy in a wide load range from low load to high load. Therefore, when a workpiece is mounted, an appropriate load can be applied, the workpiece can be prevented from being broken or chipped, and good bonding quality can be obtained. Furthermore, since the load can be adjusted at high speed, it can be output with higher accuracy.

  When the linear motor is a linear motor or a linear actuator, a driving mechanism can be simplified because a driving force can be applied to an object to be driven without contact. In addition, since high responsiveness can be obtained, it is possible to follow a steep gradient, there are few changes over time in characteristics, and there are advantages such as excellent maintainability and controllability.

  If the first pressing means and the second pressing means are arranged on the axial center of the crimping tool, a force can be applied to the center of gravity of the mechanism, and an excessive moment load is not generated. Vibration can be reduced. Therefore, it is possible to mount the workpiece without damaging it, and the mechanism can be simplified by not generating an extra moment load or the like, so that the apparatus can be made compact.

  If the first pressing means is disposed on the opposite side of the second pressing means, the pressure receiving area of the first pressing means can be increased, so that the efficiency is improved and the size of the second pressing means is reduced. As a result, the apparatus can be made more compact.

  By providing a load detector and control means, it is possible to accurately detect the load applied to the workpiece, and to stably control the load applied to the workpiece by feedback correcting the difference between the set load and the detected load. And better crimping quality can be obtained.

  Embodiments of the present invention will be described below with reference to FIGS.

  FIG. 1 shows a workpiece mounting apparatus according to the present invention. This workpiece mounting apparatus mounts an electronic component (work) 10 such as a semiconductor chip on a predetermined position of a mounting board (board) 11 with an adhesive made of solder 13. The semiconductor chip 10 is configured to be pressurized and heated toward the substrate 11.

  As shown in FIG. 1, the workpiece mounting apparatus includes a first pressing unit 1 and a second pressing unit 2 that apply a load for pressing the workpiece 10 to the crimping tool 5, and a first pressing unit 1 and a second pressing unit. 2, the pressurizing body 3 that also functions to detect the load applied to the work 10 and the control means 17 that controls the pressing force by the second pressing means 2. The first pressing means 1 and the second pressing means 2 are disposed on the axial center of the crimping tool 5, and the first pressing means 1 is disposed on the opposite side of the second pressing means 2.

  The 1st press means 1 is comprised with the air actuator. That is, the air actuator includes a hollow cylindrical body 9 to which compressed air is supplied, a pressure receiving portion 4 that receives a pressing force of the compressed air, and a pressure receiving portion 4 that is connected to the crimping tool 5 to reduce the pressing force of the compressed air. It is composed of a transmission portion 8 that transmits to the crimping tool 5. The cylindrical body 9 is provided with a hole 12 through which compressed air (high pressure gas) is supplied from a compressed air supply source (not shown). When the pressure receiving portion 4 receives the pressure of compressed air, a pressing force corresponding to the pressure receiving area is generated in the cylindrical body 9 and can be applied to the crimping tool 5 via the transmission portion 8. In this case, the pressure of the compressed air supplied to the cylinder 9 can be controlled by a control means for the air actuator (not shown). That is, the pressing force of the air actuator can be controlled when the control means inputs the load command value.

  The second pressing means 2 is composed of a linear motor. Linear motors are roughly classified into linear motors and linear actuators. A linear motor is a drive device that gives a linear motion (reciprocating motion) directly to an object by electromagnetic force, and a linear actuator is not a linear rotation type of a cylindrical rotary motor, It has a unique electromagnetic configuration and is different from a linear motor. Linear motors include linear induction motors, linear synchronous motors, linear DC motors, linear hybrid motors, and linear pulse motors. The linear actuator includes a linear vibration actuator, a linear electromagnetic solenoid, and a linear electromagnetic pump.

  In the present embodiment, the linear motor is configured by a voice coil motor that is a linear DC motor. That is, the voice coil motor has a magnet disposed on the outer peripheral side of the crimping tool 5 and a coil disposed on the outer peripheral side of the magnet. When an electric current is passed through the coil, a thrust is generated between the magnetic flux and the crimping tool 5 can be moved upward or downward. Further, when a reverse current is passed through the coil, the crimping tool 5 can be moved in the reverse direction. In this case, the magnitude of the current flowing through the coil can be controlled by the control means 17 for the linear motor so that the thrust applied to the crimping tool 5 can be controlled at a high speed and the direction of the current flowing through the coil can be controlled. Thus, the direction of thrust applied to the crimping tool 5 can be controlled. Thereby, the adjustment load which correct | amends the difference of the output load by a 1st press means from a command value can be provided. In this embodiment, the air actuator and the linear motor are provided as the control means. However, it is also possible to provide one that controls both the air actuator and the linear motor at the same time. Good.

  A pressure member 3 that applies a load to the workpiece 10 is provided at the tip of the crimping tool 5. The pressurizing body 3 includes a load detector 16 (see FIG. 3) that detects a load applied to the workpiece 10.

  Next, a mounting method for mounting the semiconductor chip 10 on the substrate 11 using the work mounting apparatus will be described. First, the work mounting apparatus is moved to above the substrate 11 on which the semiconductor chip 10 is to be mounted. Thereafter, a predetermined amount of compressed air is supplied to the air actuator, and the setting means 15 (see FIG. 3) controls the load to be set in advance. That is, a command value serving as a set load is output to the air actuator from the air actuator control means (not shown).

  In this case, the load applied to the semiconductor chip 10 is detected by the load detector 16. For example, when the load detector 16 detects a cylinder output value as shown by the dotted line in FIG. 2, an excess or deficiency from the load command value indicated by the solid line in FIG. . Note that the load command value as shown by the solid line in FIG. 2 assumes a load value that can obtain an optimal bonding state of the solder 13 to the semiconductor chip 10 in the crimping process between the semiconductor chip 10 and the substrate 11. It is determined according to the type of the workpiece 10. In addition, in order to simplify the explanation, the load command value is linear in FIG. 2, but it is actually preferable to increase it in a plurality of steps. Here, increasing stepwise means that after a constant load is applied for a predetermined time (for example, in units of 0.1 seconds), a load larger than the constant load is applied for a predetermined time.

  When an error between the cylinder output value and the load command value is detected, the error information is transmitted to the control means 17. Then, the thrust of the second pressing means 2 is controlled by the control of the control means 17 so that the pressing force of the first pressing means 1 and the second pressing means 2 substantially coincides with the load command value. That is, since the second pressing means 2 corrects an error, the pressing force (thrust) of the second pressing means 2 is positive or negative. For this reason, what reciprocates linearly, such as a voice coil motor, is optimal as the second pressing means 2. Thus, the workpiece mounting apparatus of the present invention can press the semiconductor chip 10 against the substrate 11 with a preset load command value. Thereby, when the crimping tool 5 comes into contact with the semiconductor chip 10, the solder 13 is brought into contact with a small load, and in the process of crimping the semiconductor chip 10, an optimal joining state of the solder 13 to the semiconductor chip 10 can be obtained. Such a load can be applied.

  In the present invention, since two types of pressing means, that is, an air actuator and a linear motor, are provided, the second pressing means 2 corrects an error between the load by the first pressing means 1 and the set load based on the command value. be able to. Therefore, the air actuator is not required to output with high accuracy, and can be output with high accuracy in a wide load range from low load to high load. In this case, since the linear motor can adjust the thrust by adjusting the current flowing through the coil, the error due to the air actuator can be corrected, and the load required during mounting can be accurately applied to the semiconductor chip 10. Can be loaded. For this reason, when the semiconductor chip 10 is mounted, an appropriate load can be applied, cracking or chipping of the semiconductor chip 10 can be prevented, and good bonding quality can be obtained. In addition, since the linear motor has a faster response than the air actuator, the output load error can be corrected at high speed, and output can be performed with higher accuracy.

  Since the linear motor is a linear motor, it is possible to apply a propulsive force in any direction without contact with the object to be driven, and the drive mechanism can be simplified. In addition, since high responsiveness can be obtained, it is possible to follow a steep gradient, there are few changes over time in characteristics, and there are advantages such as excellent maintainability and controllability.

  Since the first pressing means 1 and the second pressing means 2 are arranged on the axial center of the crimping tool 5, a force can be applied to the center of gravity of the mechanism, and an extra moment load is generated. Therefore, vibration during operation can be reduced. Therefore, it is possible to mount the workpiece without damaging it, and the mechanism can be simplified by not generating an extra moment load or the like, so that the apparatus can be made compact.

  Since the first pressing means 1 is disposed on the side opposite to the workpiece of the second pressing means 2, the pressure receiving area of the first pressing means 1 can be increased, so that the efficiency is improved and the second The pressing means 2 can be downsized, and the apparatus can be further downsized.

  By providing the load detector 16 and the control means 17, the load applied to the semiconductor chip 10 can be detected accurately, and the semiconductor chip 10 is loaded by feedback correcting the difference between the set load and the detected load. The load can be stably controlled, and a better pressure bonding quality can be obtained.

  As described above, the embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and various modifications can be made. For example, even if the air cylinder and the linear motor are arranged in reverse. Good. Further, the load detector 16 may be attached to the lower surface of the semiconductor chip 10. In this case, there is an advantage that the weight of the crimping tool 5 which is a movable part can be reduced, and the impact load caused by applying the load can be reduced. The number of air actuators is not limited to one and may be two or more. The shape of the crimping tool 5 is not limited to a columnar shape, but can be a cylindrical one or a quadrangular column as long as it can be pressed by an air actuator and can be pressed by a linear motor. Various shapes can be employed.

  This work mounting apparatus can also be used for a die bonder provided with a collet that adsorbs the semiconductor chip 10. That is, instead of the pressurizing body 3, a collet that can pick up and hold the semiconductor chip 10 may be used. In this case, the work mounting apparatus can be moved in the XYZ directions by the conveying means, picks up the semiconductor chip 10 from the supply unit to which the semiconductor chip 10 is supplied, holds it by a collet, and performs a lead frame as a bonding position. The substrate 11 is pressed (crimped). Thus, the workpiece mounting apparatus can be used for a die bonder, a flip chip bonder, or the like.

  In the present invention, the linear motor includes a piezoelectric element or an ultrasonic motor. A piezoelectric element is a kind of ferroelectric material, which generates a voltage when a force such as vibration or pressure is applied, and conversely expands and contracts when a voltage is applied. There are monomorphs with a structure in which a thin piezoelectric element and a metal plate are bonded together, bimorphs with a structure in which two piezoelectric elements are bonded together, and a stacked type in which a large number of piezoelectric elements are stacked in a rod shape. When constituted by a piezoelectric element, it has a large displacement at a low voltage, is highly rigid and has good responsiveness, and is small and lightweight. An ultrasonic motor is a motor that drives a rotor or a linear driven body using ultrasonic vibration. There are traveling wave type / standing wave type based on wave principle, resonant type / non-resonant type based on vibration mode, and disc type / flat plate type / wedge type based on shape. When configured with an ultrasonic motor, high torque can be obtained at a low speed of several tens to several hundreds of revolutions per minute, so that direct drive is possible without requiring a gear reduction mechanism. In addition, since the rotor inertia (inertia) is small and the braking force due to the friction of the motor is large, it exhibits excellent responsiveness, the speed control can be changed steplessly, and the mechanical time constant is 1 msec or less. Also, it has excellent controllability, and highly accurate speed control and position control are possible. In addition, it has a simple structure and light weight, requires no gear deceleration at low speed, and uses vibration in the ultrasonic region that cannot be heard by the human ear as a drive source, so it has the advantage that the operation sound is extremely quiet. is there.

It is a simplified perspective view of the workpiece | work mounting apparatus which shows embodiment of this invention. It is a graph which shows the load loaded on a workpiece | work when bonding using the workpiece | work mounting apparatus of this invention. It is a block diagram which shows the mechanism which controls the load loaded with the workpiece | work mounting apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st press means 2 2nd press means 5 Crimping tool 10 Workpiece 16 Load detector

Claims (6)

A workpiece mounting device comprising a crimping tool for pressing a workpiece and first and second pressing means for applying a load for pressing the workpiece to the crimping tool,
The first pressing means includes an air actuator that applies a load based on a command value to the crimping tool,
The second pressing means is composed of a linear motor that applies a load for correcting a difference in output load by the first pressing means from a command value,
A workpiece mounting apparatus that applies a set load, which is a load required at the time of mounting, to the workpiece by the first and second pressing means.   The workpiece mounting apparatus according to claim 1, wherein the linear motor is a linear motor.   2. The workpiece mounting apparatus according to claim 1, wherein the linear motor is a linear actuator.   The work mounting apparatus according to any one of claims 1 to 3, wherein the first pressing means and the second pressing means are arranged on an axis of a crimping tool.   The work mounting apparatus according to any one of claims 1 to 4, wherein the first pressing means is disposed on a side opposite to the work of the second pressing means.   A load detector for detecting a load applied to the workpiece, and detecting an excess or deficiency between the load information detected by the load detector and the set load, and controlling the second pressing means based on this excess or deficiency, The work mounting apparatus according to claim 1, further comprising a control unit that corrects the load to be a set load.

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