JP2002164646A - Soldering and removing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a soldering and removing device having a function of moving an electronic component with a pressure suitable for soldering and removing without applying an excessive pressure to the component. SOLUTION: The device is provided with a vacuum bit 12 for sucking an electronic component, a hot air supplying means 13 for supplying hot air around the bit 12, a servo motor 11 for moving up and down a base having the bit 12 and the means 13 against an electronic circuit board P, and a table 3 for holding the board P to move it in a horizontal direction. In the device, a load cell 15 detects a load of a vacuum pipe 14 for supplying a negative pressure to the bit 12 to control the motor 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for positioning and soldering an electronic component to a printed circuit board, and for removing an electronic component soldered to the printed circuit board.

[0002]

2. Description of the Related Art When mounting an IC on a printed circuit board, a soldering device adsorbs the IC to a vacuum bit at a tip end of a hot air injection device which can be moved up and down as shown in, for example, JP-A-8-46351. Then, the IC is sucked, dropped and placed on the corresponding conductive pattern on the printed circuit board on which the cream solder is applied, and heated by blowing hot air controlled at a constant temperature from a nozzle. .
Removal of an IC soldered to a printed circuit board is performed by bringing a nozzle into contact with an IC on the board, heating, adsorbing a vacuum bit in the nozzle, and removing the IC from the board.

[0003]

However, the temperature must be set far from the original melting temperature of the solder, and the position of the component in the vertical axis (Z-axis) direction must be controlled. It is difficult to set the pressing force accurately because the pressing position is limited by a method of restricting the descending position by a stopper or by a biasing force such as a spring or a weight. Furthermore, semiconductor devices having a thickness of several millimeters or less, such as recent ultra-fine parts such as CSP, micro BGA, and flip chips, are easily damaged by a pressing force, a positional error in the Z direction, and thermal expansion during heating. There is a problem of doing. The present invention has been made in view of such a problem, and an object of the present invention is to move an electronic component with a pressure suitable for soldering or removal without applying excessive pressure to the electronic component. It is an object of the present invention to provide a soldering and detaching device having a function of causing the soldering and the removing.

[0004]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a vacuum bit for sucking an electronic component, a hot air supply means for supplying hot air near the vacuum bit, the vacuum bit and In an electronic component soldering / dismounting apparatus comprising: elevating means for elevating and lowering a base on which a hot air supply means is mounted on a circuit board; and a table which holds an electronic circuit board and moves in a horizontal direction, a negative pressure Load detecting means for detecting the load of the vacuum pipe for supplying the pressure, and controlling the elevating means based on a signal from the load detecting means.

[0005]

When the electronic component held by the vacuum bit is pressed against the circuit board with a predetermined pressure, the descent stops, so that the electronic component is prevented from being damaged due to excessive stress acting on the electronic component. Is done.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a first embodiment of the present invention. Figures 1 (a) and (b)
1 is a view showing an embodiment of the apparatus of the present invention, each of which includes a horizontal base 1 and a vertical base 2, and an XY table 3 for setting a planar position of a circuit board P is provided on the horizontal base 1. The slide covers 4 and 5 are provided on the upper part. On the other hand, the vertical base 2 is provided with a hot air injection device 6, a touch panel display 7, and an emergency stop command switch 8.

FIG. 2 shows an outline of the above apparatus. A hot air injection device 6 is mounted on a vertical base 2 so as to be vertically movable on a horizontal base 1 by a servomotor 11 connected to an encoder 10. Have been. The hot air injection device 6 has a vacuum bit 1 at its lower end for adsorbing a semiconductor device by negative pressure.
An air heater 13 for supplying hot air to the vacuum bit 12, a vacuum pipe 14 for supplying a negative pressure to the vacuum bit 12, and an upper portion of the vacuum pipe 12 for supporting the vacuum bit 12. And a temperature detecting means, in this embodiment, a thermocouple 16.

As shown in FIG. 3, a load cell 15, a support 30 capable of elastically deforming in a vertical direction while preventing rocking in a horizontal plane, an elastic plate having a cross-shaped branch 31 in this embodiment. The vacuum pipe 14 is penetrated and fixed at the center, and a strain gauge 32 is attached to the branch portion 31.

The thermocouple 16 has two thermocouple wires 34,
The thermal contact 36 is formed so as to penetrate through the vacuum pipe 14 from the upper end to the lower end and to contact the upper surface of the semiconductor device D held by the vacuum bit 12 as shown in FIG. . Note that reference numeral 37 in FIG.
Transmits hot air from the air heater 13 to the vacuum bit 12.
Shows the nozzle that guides the air.

Below the vacuum bit 12, an imaging device 17 for photographing the back surface of the semiconductor device gripped by the vacuum bit 12 and the front surface of the circuit board P is disposed so as to be able to advance and retreat. This imaging device 17 includes a beam splitter, a light emitting element arranged in a rectangular shape, and an imaging element as seen in Japanese Patent Application Laid-Open No. Hei 7-115300, and combines the upper and lower images with the beam splitter to form a CCD. To convert the signal into an electric signal. Further, between the back surface of the XY table 3 and the base 1, a temperature detecting means 18 and a hot air supply device 19 are provided at a position opposite to the vacuum bit on the back surface of the circuit board P, in contact with the circuit board P. A bottom heater is provided.

The temperature detecting means 18 and the hot air supply device 1
Reference numeral 9 denotes a unit which is integrally mounted on a base 40 rotatable about a shaft 39 by a driving means 38 as shown in FIG. 5, and applies hot air to the back surface of the circuit board P by a nozzle 40 communicating with the hot air supply device 19. It is configured to supply. Further, at a position facing the parts feeder 20 for supplying the semiconductor component D and a position facing the circuit board P, height measuring means, in this embodiment, laser distance measuring devices 21 and 22 are arranged.

On the other hand, the control device 23 comprises the encoder 10,
In response to the signals from the load cell 15, the thermocouples 16 and 18 and the command from the touch panel 7, the hot air injection device 6 is raised and lowered, the temperature of the hot air, the pressing force by the vacuum bit 12,
It is configured to control the lifting force, measure the thickness of the semiconductor device D by a signal from the laser distance measuring devices 21 and 22, and further change the display mode of the touch panel 7.

As shown in FIG. 6, the touch panel 7 has a display area 50 in a partial area, in this embodiment, an upper right quarter, a movement control button of the hot air supply device 19 around the display area 50, and a lower part thereof. And a control button for moving the imaging device 17. Reference numeral 51 in the figure indicates a knob for manual operation.

In this embodiment, a heating profile suitable for the semiconductor device D to be soldered by the touch panel 7 is set by a setting button or data of a heating profile (FIG. 7) registered in advance is called. When the semiconductor device D to be hot-air soldered is transported to a predetermined position by the parts feeder 20, the laser distance measuring device 2
1, the distances L1 and L2 between the base of the parts feeder 20 and the surface of the semiconductor device D are measured to detect the thickness (L1-L2) of the semiconductor device D.

The semiconductor device D is transported directly below the vacuum bit 12 by the parts feeder 20 and is held by the vacuum bit 12. In this state, as shown in FIG. 4, the thermal contact 36 of the thermocouple contacts the surface of the semiconductor device D, and the surface temperature of the semiconductor device D is input to the control device 23 as a signal.

Then, the vacuum bit 12 is moved to a centering device (not shown) to regulate the relative position between the vacuum bit 12 and the semiconductor device, and the XY table 3 is moved to move a predetermined conductive pattern of the circuit board P to the vacuum bit 12. Move directly below. The centering device can be configured by urging a claw that regulates four sides of the semiconductor device in the center direction by urging means, as shown in, for example, Japanese Patent Application Laid-Open No. 5-48299.

When the imaging device 17 is moved to this area as required, the image of the bottom surface of the semiconductor device D and the conductive pattern of the circuit board are combined by a half mirror and displayed on the image display area 50 of the touch panel 7. . While viewing this image, the XY table 3 is moved by a fine movement device (not shown).
Fine-tune the position of.

When the positioning is completed, the cover 4,
When the button 5 is closed and the button is pressed, the servomotor 11 operates at a high speed to lower the hot air injection device 6, and the height is detected by the encoder 10. At the stage where the servo motor 11 has descended to the predetermined position, the servo motor 11 rotates at a low speed and continues to descend further. When the bottom surface of the semiconductor device D contacts the circuit board P,
The reaction force acts on the vacuum pipe 14 and the load cell 15
Outputs a load signal. When the load is a predetermined value, for example, 0.
When it reaches 1 g, the servomotor 11 stops.
As a result, the semiconductor device D is positioned on the circuit board P with a pressure suitable for soldering.

Next, when a command for heating is given by the touch panel 7, the thermal contacts 36 in contact with the surface of the semiconductor device D are contacted.
The power to the air heater 13 is controlled such that the time pattern of the temperature detected by the above becomes a preset state. The semiconductor device D accompanying this heating and the circuit board P
When the reaction force (pressure) to the vacuum bit 12 rises due to thermal expansion, the load of the load cell 15 also increases through the vacuum pipe 14, so that the servomotor 11 reversely rotates to keep the pressing force of the semiconductor device D constant. maintain.

As a result, the semiconductor device D is constantly pressed against the circuit board with a constant pressure, so that damage to the semiconductor device D and short-circuit due to crushed solder can be prevented. When the solder cream applied to the circuit board P or the solder particles of the semiconductor device D is melted,
The supply of hot air is stopped, and when the solder is solidified, the servomotor 11 is rotated in the reverse direction, and the hot air injection device 6 is raised to the original position.

At the time of soldering, a temperature detecting means 18 and a hot air supply device 19 constituting a bottom heater as required.
Are advanced to the circuit board side, the temperature detecting means 18 is brought into contact with the circuit board P, and the hot air supply device 19 is operated so that the temperature of the circuit board becomes a predetermined pattern so that the circuit board side is also heated. You may. By heating the circuit board P in this way, the semiconductor device D can be prevented from overheating and soldering can be reliably performed.

On the other hand, when the semiconductor device D soldered to the circuit board P is to be removed for replacement, the XY table 3 is moved so that the semiconductor device faces the laser distance measuring device 22 and the semiconductor device D is removed. Distance L3 to the surface of device D
Is measured. Next, the semiconductor device D of the circuit board P is moved directly below the vacuum bit 12, and a composite image of the semiconductor device D and the vacuum bit 12 is displayed on the touch panel by the imaging device 17, and the position is finely adjusted.

When the button is pressed at the stage when the positioning is completed, the servomotor 11 operates at a high speed to lower the hot air injection device 6, and the height thereof is detected by the encoder 10. At the stage where the servo motor 11
Rotates at low speed and continues to descend further. When the vacuum bit 12 contacts the semiconductor device, the vacuum pipe 1
4 applies a reaction force to the load cell 15 to output a load signal. When the load reaches a predetermined value, for example, 0.1 g, the servomotor 11 stops.

Next, when heating is started, the air heater 13 is set so that the time pattern of the temperature detected by the thermocouple in contact with the semiconductor surface becomes a preset state.
When the power to the semiconductor device D is controlled and the semiconductor device D is fixed and melted, when the servo motor 11 is driven in the reverse direction, the semiconductor device D is gripped by the vacuum bit 12 and peeled off from the circuit board P.

If a negative load signal is output from the load cell 15 at this time, since the unmelted solder is present, the servo motor 11 is rotated forward and hot air is supplied again to reheat the solder. Thus, the semiconductor device can be safely and securely removed without applying an excessive load to the semiconductor device D or the circuit board P. Further, in the above-described embodiment, an example has been described in which the semiconductor device is soldered and removed. However, it is apparent that the same effect is exerted even when applied to a small electronic component. Further, in the above-described embodiment, the temperature of the semiconductor device or the circuit board is measured by a thermocouple. However, it is obvious that the same operation can be obtained by using a resistance temperature measuring element.

[0026]

As described above, in the present invention,
Since the load detecting means for detecting the load of the vacuum pipe for supplying the negative pressure to the vacuum bit is provided, and the lifting means is controlled based on a signal from the load detecting means,
When the electronic component held by the vacuum bit is pressed against the circuit board with a predetermined pressure, the descent is stopped, and damage to the electronic component due to excessive stress can be prevented.

[Brief description of the drawings]

FIGS. 1 (a) and 1 (b) are views showing an embodiment of the apparatus of the present invention with a cover closed and a cover opened, respectively.

FIG. 2 is a configuration diagram showing an embodiment of the apparatus of the present invention.

FIGS. 3A and 3B are a cross-sectional view and a top view, respectively, showing one embodiment of a load cell constituting the same device.

FIG. 4 is a view showing an embodiment of a thermocouple constituting the above device in a structure near a vacuum bit.

FIG. 5 is a view showing one embodiment of a bottom heater used in the above device.

FIG. 6 is a diagram showing one embodiment of a touch panel used in the above device.

FIG. 7 is a diagram illustrating an example of a heating profile of a semiconductor device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Horizontal base 2 Vertical base 3 Table 4, 5 Slide cover 6 Hot air injection device 7 Touch panel display 8 Emergency stop command switch 10 Encoder 11 Servo motor 12 Vacuum bit 13 Air heater 14 Vacuum pipe 15 Load cell 16, 18 Thermocouple 17 Imaging device Reference Signs List 18 Temperature detecting means 19 Hot air supply device 20 Parts feeder 21, 22 Laser distance measuring device 23 Control device 30 Support body 31 Branch 32 Strain gauge 34, 35 Thermocouple wire 36 Hot contact

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Claims (5)

[Claims] 1. A vacuum bit for sucking an electronic component, hot air supply means for supplying hot air to the vicinity of the vacuum bit, and elevating means for raising and lowering a base on which the vacuum bit and the hot air supply means are mounted on a circuit board. When,
An electronic component soldering / dismounting apparatus comprising a table which holds an electronic circuit board and moves in a horizontal direction, the apparatus further comprising: load detecting means for detecting a load on a vacuum pipe for supplying a negative pressure to the vacuum bit; A soldering / dismounting device for controlling the lifting / lowering means based on a signal from the means. 2. The soldering method according to claim 1, wherein the base is controlled to move up and down so that the load detected by the load detection unit is constant during a period in which the hot air is supplied by the hot air supply unit. Removal device 3. The soldering and removing device according to claim 1, wherein temperature detecting means for abutting on the surface of the electronic component attracted to the vacuum bit is built in the vacuum bit. 4. The apparatus according to claim 1, wherein the temperature of the hot air is controlled based on preset temperature profile data. 5. The apparatus according to claim 1, further comprising: a temperature detection unit that contacts the back surface of the electronic circuit board; and a hot air supply unit, in a region below the vacuum bit and on a back surface of the table. Soldering and removing device as described.