JP5416483B2 - Electronic component mounting equipment - Google Patents

Description

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

  For example, when a semiconductor chip as an electronic component is mounted on a substrate such as a lead frame, the semiconductor chip is sucked and held at the lower end of a mounting tool and mounted by pressing the semiconductor chip against the substrate.

  At the time of mounting, if the pressing force (mounting load) by which the mounting tool presses the semiconductor chip against the substrate is small, mounting failure may occur, and if it is too large, the semiconductor chip may be damaged, resulting in cracking or chipping. Therefore, the pressing force needs to be set to an optimum value according to the thickness of the semiconductor chip or the substrate.

  A general mounting apparatus that performs such mounting includes a driving body that is driven in a vertical direction by a driving source. The driving tool is provided with the mounting tool displaceable in the vertical direction. The mounting tool is configured such that a load (holding force) that is a resistance to displacement in the vertical direction is applied to the drive body by a voice coil motor, and the drive tool is lifted relative to the drive body. This is detected by a gap sensor.

  The mounting tool is lowered at a high speed from the rising standby position to a predetermined height position by the driver. The lowering during this period is the first search lowering. When the driving body moves down the first search at a high speed, the mounting tool is subjected to an acceleration accompanying the lowering of the driving body, and thus swings in the vertical direction due to the acceleration.

  Therefore, when the mounting tool is moved down together with the driving body at a high speed for the first search, a maximum load is generated in the voice coil motor so as not to swing up and down with respect to the driving body. The implementation tool is held. At this time, the load applied to the mounting tool by the voice coil motor is defined as a first load.

  When the mounting tool reaches a predetermined position, that is, reaches the end height of the first search lowering, the mounting tool decelerates the lowering speed and starts the second search lowering. At this time, the load applied to the mounting tool by the voice coil motor is changed to a second load that is sufficiently lower than the maximum load when the first search is lowered.

  If the holding force of the mounting tool is changed to a second load that is lower than the first load, when the semiconductor chip held on the tip surface of the mounting tool hits the substrate during the second search lowering, Since the mounting tool can be raised relative to the driving body, the impact applied to the semiconductor chip is reduced, and damage and chipping are prevented.

  When the mounting tool rises relative to the driver when the semiconductor chip hits the substrate, this is detected by the gap sensor. When the gap sensor detects that the semiconductor chip has hit the substrate, the load applied by the voice coil motor to the pressing tool is changed to a mounting load suitable for mounting the semiconductor chip on the substrate. The This mounting load is larger than the second load and smaller than the first load. Thereby, the semiconductor chip is mounted on the substrate with an optimal mounting load.

  Patent Document 1 discloses that when a pellet is mounted on a frame, its mounting load is controlled using a voice coil motor.

JP-A-5-131386

  By the way, as described above, when the mounting tool decelerates the descending speed from the first search lowering and shifts to the second search lowering as described above, the load applied by the voice coil motor to the mounting tool is the voice coil motor. The first load, which is the maximum load, is reduced to a second load that is sufficiently lower than the first load.

  When the load applied to the mounting tool is reduced from the first load to the second load at once, the lowering speed of the mounting tool is reduced from the lowering speed of the first search lowering to the lowering speed of the second search lowering. When negative acceleration occurs in the mounting tool, the mounting tool repeatedly vibrates in the vertical direction with respect to the driver due to the acceleration.

  When the mounting tool vibrates in the vertical direction with respect to the driving body, detection by the gap sensor may not be performed accurately. In other words, the surface detection, which is the detection of the height position of the upper surface of the substrate on which the semiconductor chip is mounted, may not be accurately performed by the gap sensor.

  Therefore, in such a case, it is sometimes impossible to precisely feedback control the descent of the mounting tool based on the surface detection, or the detection by the gap sensor is waited until the vibration of the mounting tool with respect to the driver is settled. Therefore, the tact time becomes longer and the productivity is reduced accordingly.

The present invention provides an electronic component mounting apparatus that prevents the mounting tool from swinging up and down with respect to a driver when the mounting tool is decelerated from a first search lowering speed to a second search lowering speed. It is in.

The present invention is an electronic component mounting apparatus for mounting an electronic component on a substrate,
A driving body driven in the vertical direction by a driving source;
A mounting tool is provided on the drive body so as to be vertically displaceable , and has a hook that hits the upper end surface of the drive body at the upper portion thereof,
A height detecting means for detecting that the electronic component held by the mounting tool is in contact with the substrate by detecting a relative movement of the mounting tool with respect to the driving body;
Load setting means for applying a load for preventing the mounting tool from being displaced in the vertical direction with respect to the driving body;
The driving body is held in a state where the saddle is in contact with the upper end surface of the driving body with respect to the mounting tool, and the mounting tool is held in a state of having resistance in the upward direction with respect to the driving body. The first load is applied when the drive source is lowered from the first height to the second height by the drive source at the first speed, and the drive body is moved from the second height to the third height. While applying a load so as to gradually decrease from the first load to a second load smaller than the first load when descending at a second speed slower than the first speed, And a control means for controlling the load setting means so that the second load is applied when the electronic component held by the mounting tool comes into contact with the substrate. In the device.

The control means maintains the load applied to the mounting tool by the load setting means at the second load and lowers the driving body to the third height position, and then applies the load to the mounting tool. It is preferable to change the load to a third load that is larger than the second load and smaller than the first load .

According to the present invention, when the mounting tool is decelerated from the first search lowering speed to the second search lowering speed, it is possible to prevent the mounting tool from swinging up and down with respect to the driving body.

1 is a schematic configuration diagram of a mounting apparatus showing an embodiment of the present invention. The figure which shows the relationship between the height of a drive body , the load given to a mounting tool, and the detection signal which a gap sensor detects.

An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 shows a schematic configuration of a mounting apparatus according to the present invention, and this mounting apparatus has a gantry 1 whose side shape is an inverted L shape. A linear guide 2 is provided on the vertical surface 1a of the gantry 1 along the vertical direction. A driving body 3 is supported on the linear guide 2 by engaging the receiving portion 3a in a movable manner.

  A screw shaft 4 having a vertical axis is screwed onto the driving body 3. The screw shaft 4 is rotationally driven by a drive source 5 provided on the upper surface of the horizontal surface 1 b of the gantry 1. Thereby, the driving body 3 is driven in the vertical direction along the linear guide 2.

  One end of a bracket 6 is fixed to the driving body 3. A cylindrical holder 7 is attached to the other end of the bracket 6. A mounting tool 8 is inserted into and supported by the holder 7 so as to be movable in the vertical direction. The mounting tool 8 has upper and lower ends protruding from the upper and lower ends of the holder 7, and an electromagnetic coil 9 is mounted on the outer peripheral surface of the upper end.

  The electromagnetic coil 9 is accommodated in a cylindrical yoke 10. The yoke 10 is attached to the other end of a connecting member 11 having one end connected to the bracket 6. The electromagnetic coil 9 and the yoke 10 constitute a voice coil motor 12 as load setting means.

  Thereby, if the voltage (current) applied to the electromagnetic coil 9 is controlled, a load for urging the mounting tool 8 in the downward direction is applied. In other words, the mounting tool 8 has a height corresponding to the voltage applied to the electromagnetic coil 9, that is, the ascending direction, at the height of the descending limit where the flange 8a provided on the upper portion of the mounting tool 8 hits the upper end surface of the holder 7. It is held in a state having a predetermined resistance. FIG. 1 shows a state in which the mounting tool 8 is in the ascending limit position with respect to the holder 7.

  One end of the suction hole 14 is opened at the front end surface of the mounting tool 8. The other end of the suction hole 14 opens to the outer peripheral surface of the tip portion of the mounting tool 8, and a tube 15 communicating with a suction pump (not shown) is connected to the other end.

  Accordingly, a suction force can be generated in the suction hole 14 opened in the front end surface of the mounting tool 8, and the semiconductor chip 16 as an electronic component is sucked and held on the front end surface of the mounting tool 8 by the suction force. Be able to.

  A voltage is applied to the electromagnetic coil 9 to hold the mounting tool 8 at a lower limit with respect to the holder 7 of the driving body 3 with a predetermined load. When it rises relatively, the rise is detected by a gap sensor 17 as height detecting means.

The gap sensor 17 is attached to the holder 7 with an L-shaped support 7a with the detection surface 17a facing downward in the vertical direction. One end of a detection plate 18 is connected to the mounting tool 8. The other end of the detection plate 18 faces the detection surface 17 a of the gap sensor 17.

When the mounting tool 8 rises relative to the holder 7 of the driving body 3 and the gap d between the gap sensor 17 and the detection plate 18 becomes smaller than a preset gap, this is the case. 17 is detected.

  The detection signal of the gap sensor 17 is output to the control device 19. The control device 19 controls the intensity of the voltage applied to the electromagnetic coil 9 based on the detection signal of the gap sensor 17 as described later. Further, the control device 19 controls the lowering drive of the driving body 3 by the driving source 5 as described later on the basis of a preset lowering speed and height.

Next, the operation of mounting the semiconductor chip 16 on the plate surface of the substrate S by the mounting apparatus having the above configuration will be described with reference to FIG. In FIG. 2, a broken line A indicates the relationship between the height of the driving body 3 and time, and a broken line B indicates the relationship between the load applied to the mounting tool 8 by the voice coil motor 12 and time. This load is proportional to the voltage value applied to the voice coil motor 12.

The broken line C is against the load applied by the voice coil motor 12 from the change of the gap ( interval d ) detected by the gap sensor 17, that is, from the state in which the mounting tool 8 is held at the lower limit position by the driving body 3. The relationship between the displacement that rises relative to the driving body 3 and time is shown. That is, the state of up and down deflection of the mounting tool 8 is shown.

The driver 3 waits at the first height indicated by H1 of the broken line A before the mounting operation is started. At this time, the semiconductor chip 16 delivered by a delivery tool (not shown) is sucked and held on the front end surface of the mounting tool 8.

  When the mounting operation is started by the control device 19 at time t1, the mounting tool 8 starts descending together with the driving body 3 at the first speed V1 (first search speed). At this time, the control device 19 applies a voltage that lowers the mounting tool 8 to the lower limit relative to the driving body 3 to the voice coil motor 12. That is, the mounting tool 8 is held by the first load indicated by W1 on the broken line B (the maximum load of the voice coil motor 12).

At time t2, the driving body 3 is stored in advance from the first height H1 to a predetermined height, that is, the mounting tool 8 reaches a predetermined distance with respect to the upper surface of the substrate W on which the semiconductor chip 16 is mounted. approaching, second height H2 when lowered to (shown in broken line a), the control unit 19 a lowering speed of the driver 3 second speed V2 slower than the first speed V1 (second search speed) To lower to a third height H3. The time for the driving body 3 to reach the third height H3 is t4.

The control device 19 changes the descending speed of the driving body 3 from the first speed V1 to the second speed V2 at time t2, and at the same time, gradually reduces the voltage applied to the voice coil motor 12.

  As a result, the load applied to the mounting tool 8 gradually decreases from the first load W1 toward the second load W2 as indicated by the broken line B. That is, it decreases at the polygonal line B with an inclination. The load applied to the mounting tool 8 becomes the second load W2 at time t3 before time t4. This time t3 will be described later.

Thus, when the descending speed of the driving body 3 is decelerated from the first speed V1 to the second speed V2, the load applied to the mounting tool 8 by the voice coil motor 12 is suddenly changed to W2, that is, on the broken line B. It did not reduce so that it might become perpendicular | vertical, but it decreased so that it might incline in the broken line B gradually from the load W1 to the load W2.

  Therefore, when the speed is reduced and negative acceleration is generated in the mounting tool 8, the mounting tool 8 is held by the driving body 3 with the first load W1, and gradually increases from the first load W1 to the second load W2. Therefore, the mounting tool 8 does not vibrate in the vertical direction with respect to the driver 3.

While the driving body 3 descends from the second height H2 toward the third height H3, the semiconductor chip 16 attracted and held on the front end surface of the mounting tool 8 is the substrate S (shown in FIG. 1). It hits the top surface. The time at this time is t3 described above, and the height of the driving body 3 is a height h between the second height H2 and the third height H3.

When the semiconductor chip 16 held by the mounting tool 8 at the height h hits the upper surface of the substrate S, the mounting tool 8 rises relative to the driver 3. Thereby, since the gap the gap sensor 17 detects changes, it can be seen that contact without mounting tool 8 on the upper surface of the substrate S is deflected by the change.

The detection signal of the gap sensor 17 is output to the control device 19. In this case, since the mounting tool 8 is not deflected in the vertical direction relative to the drive member 3 as described above, since the displacement point of the mounting tool 8 can be accurately determined, the height of the substrate S top by the gap sensor 17 Detection is performed with high accuracy.

  When the semiconductor chip 16 hits the upper surface of the substrate S, the load applied to the mounting tool 8 by the voice coil motor 12 is changed from the first load W1 to the second load W2 smaller than the first load W1. is decreasing.

The control device 19 that has received the detection signal from the gap sensor 17 keeps the driving body 3 at the height described above in a state where the load applied by the voice coil motor 12 to the mounting tool 8 is maintained at the second load W2. Lower from h to a third height H3.

If the driving body 3 is depressed by a distance of (h−H3) and the driving body 3 is lowered to the third height H3, the control device 19 increases the voltage applied to the voice coil motor 12. The load applied to the mounting tool 8 is changed to the load indicated by W3 on the broken line B, that is, the third load W3 that is larger than the second load W2 and smaller than the first load W1, and in that state for a predetermined time. maintain. The third load W3 is a load suitable for mounting the semiconductor chip 16 on the substrate S. As a result, the semiconductor chip 16 is mounted on the substrate S by an adhesive or the like.

When the semiconductor chip 16 is mounted on the substrate S in this way, the control device 19 sets the voltage applied to the voice coil motor 12 to 0 and raises the driving body 3 to the first height H1. Wait. When the semiconductor chip 16 to be mounted next is supplied to the lower end surface of the mounting tool 8, the above-described steps are repeated.

As described above, when the driving body 3 descends from the first height H1 to the second height H2 and decelerates the descending speed from the first speed V1 to the second speed V2, the voice coil motor 12 Thus, the load applied to the mounting tool 8 is gradually decreased to the second load W2 without abruptly decreasing from the first load W1.

Therefore, it is possible to prevent the mounting tool 8 from swinging up and down with respect to the driving body 3 when the lowering speed of the driving body 3 is switched. Such a detection can be performed with high accuracy.

In addition, since the mounting tool 8 can be prevented from swinging up and down with respect to the drive body 3 when the descending speed of the drive body 3 is switched, the mounting tool 8 is brought into contact with the upper surface of the substrate S until the swing is converged. No need to wait. As a result, the tact time required for mounting can be shortened.

  Further, since the load is gradually decreased (inclined) from W1 to W2, the mounting tool 8 is prevented from swinging, and the distance of the gap sensor 17 is maintained constant. Therefore, the semiconductor chip 16 is prevented from being cracked or chipped at time t3 when the semiconductor chip 16 contacts the upper surface of the substrate S.

  DESCRIPTION OF SYMBOLS 3 ... Drive body, 5 ... Drive source, 8 ... Mounting tool, 9 ... Electromagnetic coil, 10 ... Yoke, 12 ... Voice coil motor (load setting means), 16 ... Semiconductor chip (electronic component), 17 ... Gap sensor (High Detection means), 18 ... actuators, 19 ... control device (control means).

Claims (2)

An electronic component mounting apparatus for mounting an electronic component on a substrate,
A driving body driven in the vertical direction by a driving source;
A mounting tool is provided on the drive body so as to be vertically displaceable , and has a hook that hits the upper end surface of the drive body at the upper portion thereof,
A height detecting means for detecting that the electronic component held by the mounting tool is in contact with the substrate by detecting a relative movement of the mounting tool with respect to the driving body;
Load setting means for applying a load for preventing the mounting tool from being displaced in the vertical direction with respect to the driving body;
The driving body is held in a state where the saddle is in contact with the upper end surface of the driving body with respect to the mounting tool, and the mounting tool is held in a state of having resistance in the upward direction with respect to the driving body. The first load is applied when the drive source is lowered from the first height to the second height by the drive source at the first speed, and the drive body is moved from the second height to the third height. While applying a load so as to gradually decrease from the first load to a second load smaller than the first load when descending at a second speed slower than the first speed, And a control means for controlling the load setting means so that the second load is applied when the electronic component held by the mounting tool comes into contact with the substrate. apparatus.   The control means maintains the load applied to the mounting tool by the load setting means at the second load and lowers the driving body to the third height position, and then applies the load to the mounting tool. 2. The electronic component mounting apparatus according to claim 1, wherein the load is changed to a third load that is larger than the second load and smaller than the first load.

Images