JP2006192371A - Quantitative liquid discharge apparatus and its controlling method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a quantitative liquid discharge apparatus in which the stoppability of a liquid can be enhanced and the dripping of the liquid and the intrusion of air can be restrained after the discharge of the liquid from a nozzle is stopped. <P>SOLUTION: The quantitative liquid discharge apparatus 1 is provided with an air pressure circuit to be connected to a syringe 3 of a dispenser 14. The syringe 3 is connected to a negative pressure generating unit 5 through a stop valve 7 for negative pressure, a pressure control valve 9 for negative pressure and a check valve 8 and a pipeline 25 is kept in negative pressure. The syringe is also connected to an air pressure source unit 4 through a stop valve 6 for positive pressure and a pressure control valve 11 for positive pressure. When the liquid is discharged, the stop valve 6 for positive pressure is opened to keep the inside of the syringe 3 in positive pressure. When the discharge of the liquid is completed, the stop valve 7 for negative pressure is opened instead of the stop valve 6 so that the pressure in the syringe 3 is made to instantaneously change from positive pressure to negative pressure by the negative pressure kept in the pipeline 25. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid quantitative discharge device capable of quantitatively discharging liquid with high accuracy for purposes such as underfilling.

  2. Description of the Related Art In recent years, CSP (Chip Scale Package) has been proposed in response to demands for miniaturization and thinning of electronic devices, and semiconductor chips themselves are also demanded for miniaturization and thinning. In addition, when mounting a semiconductor chip or the like on a substrate, the lower surface is fixed to the substrate with a solder ball or the like as in the case of a BGA (Ball Grid Array) type semiconductor chip having no pins, for example. May be. In such a type, the semiconductor chip can be brought into a state of being in close contact with the substrate, and the thickness thereof can be reduced. In addition, since the number of contacts with the outside can be arranged in a plane on the flip side, many contacts can be concentrated and the chip can be greatly reduced. However, due to high-speed arithmetic processing, the temperature of the chip rises and stress concentrates on the joint, so that it may be possible that the connection of the connected solder balls becomes defective. On the other hand, dust, gas, liquid, or the like may enter the joint and cause deterioration or short circuit of the connection portion. For this reason, underfilling is performed to fill the gap with an adhesive (underfill material) discharged from the nozzle of the dispenser.

  With this underfilling, if the supply of adhesive is small, the gap will not reach the gap sufficiently, resulting in insufficient adhesion, or dust, gas, liquid, etc. may enter the joint, causing deterioration of the connection or short-circuiting. There is a fear. On the other hand, if the supply amount of the adhesive is too large, it overflows from the space to be filled and adheres to an unplanned portion of the substrate, which may damage the product. Therefore, it is necessary to strictly control the discharge amount. In addition, the viscosity of the adhesive varies depending on the application, and further varies depending on the temperature. At this time, if there is dripping from the nozzle of the dispenser, an unscheduled adhesive material is attached to the substrate, or an excessive amount of adhesive material is supplied in excess of the specified amount. On the other hand, if air enters the nozzle from the tip of the nozzle, not only the supply of the adhesive material is insufficient, but also bubbles that cause cracks may be generated. Therefore, it has been necessary to adjust the pressure in the syringe to prevent such dripping and bubbles.

Under such a background, a liquid ejecting apparatus and a liquid ejecting method as described in Patent Document 1 have been proposed. In this liquid ejection apparatus, as shown in FIG. 4, a syringe 101, a pressurized gas supply means 102 for supplying a pressurized pressure thereto, and a negative pressure supply means 104 for supplying a negative pressure for liquid retention to the syringe 101, And a two-position switching valve 103 for selectively communicating the pressurized gas supply means 102 and the negative pressure supply means 104 to the syringe 101. Further, the syringe 101 is connected to a pressure-absorbing means 109 via an exhaust pressure switching valve 108 arranged in parallel with the two-position switching valve 103. Simultaneously with the stop of the liquid discharge, the suction of the internal pressure of the syringe 101 and the supply of the negative pressure for liquid holding into the syringe 101 are started, and when the internal pressure of the syringe 101 decreases to a required value, the syringe internal pressure The liquid discharge method is characterized by stopping the suction of the liquid. According to the liquid ejection device and the liquid ejection method, the liquid running out property at the time of stopping the discharge of liquid is improved, the dripping after the stop of the discharge is prevented, and the cycle time of the discharge cycle is shortened to improve the work efficiency. I was able to.
Japanese Patent Laid-Open No. 11-290745

  However, it is necessary to change the pressure instantaneously after pressurizing for the discharge of the liquid of the syringe 101, in order to improve the liquid drainability after the discharge of the syringe 101 is stopped and to prevent the dripping after the discharge is stopped. There is. In the invention of Patent Document 1, the negative pressure supply means 4 starts the suction of the internal pressure of the syringe 101 and the supply of the negative pressure for liquid holding into the syringe 101 simultaneously with the stop of the liquid discharge. It takes a certain time to apply pressure. Therefore, there is a problem that a delay may occur even if a negative pressure is applied immediately after stopping the discharge.

On the other hand, there is a problem that excessive negative pressure may cause air to enter the nozzle.
In view of the above problems, the present invention provides a liquid fixed-quantity discharge device and a liquid fixed-quantity discharge method that can improve liquid drainage after stopping discharge of a nozzle and suppress liquid dripping and air entry after stop of discharge. There is.

  In order to solve the above-mentioned problem, in the liquid dispensing apparatus according to claim 1, a syringe that stores liquid discharged from a nozzle, a pneumatic pressure source device that applies pressure for liquid discharge to the syringe, and the syringe A negative pressure generating device that applies a negative pressure for liquid holding; a pressurizing on-off valve that opens and closes a conduit disposed between the syringe and the air pressure source device; the syringe and the negative pressure generating device; A negative pressure on-off valve that opens and closes a pipe line disposed between the negative pressure generating device and the negative pressure on-off valve, and the negative pressure of the pipe on the negative pressure on-off valve side And a check valve for maintaining the pressure, and maintaining the pressure in the pipe line between the negative pressure on-off valve and the check valve at a negative pressure equal to or lower than a predetermined pressure.

  In this invention, the negative pressure generating device is provided, and the negative pressure generated here can be maintained at a negative pressure equal to or lower than a predetermined pressure in the pipe line between the negative pressure on-off valve and the check valve. Therefore, there is an effect that a negative pressure can be immediately applied to the syringe simply by opening the negative pressure on-off valve.

  According to a second aspect of the present invention, in the liquid dispensing apparatus according to the first aspect, the conduit connected to the negative pressure on-off valve communicates with the conduit connected to the pressurizing on-off valve. Is the gist.

According to the present invention, the negative pressure maintained in the pipe line between the negative pressure on-off valve and the check valve enables the pipe line connected to the pressurization on-off valve to instantaneously become negative pressure. There is.
According to a third aspect of the present invention, in the liquid dispensing apparatus according to the first or second aspect, a negative pressure control valve is provided between the negative pressure on-off valve and the check valve. The gist.

  In the present invention, by adjusting the negative pressure maintained between the negative pressure on-off valve and the check valve, a strong negative pressure is generated between the negative pressure control valve and the check valve due to the accumulating effect. Even in this case, the negative pressure control valve can suppress excessive negative pressure to make the pressure on the negative pressure on / off valve side appropriate. Therefore, there is an effect that an appropriate negative pressure can be instantaneously applied to the syringe.

  According to a fourth aspect of the present invention, in the liquid dispensing apparatus according to the third aspect, a pressurizing pressure control valve is provided between the pressurizing on-off valve and the air pressure source device, and the pressurizing pressure control valve is The gist is that it is composed of an electropneumatic regulator.

According to the present invention, there is an effect that the pressurization when the syringe discharges the liquid can be made appropriate, and the excessive supply of the liquid due to the excessive pressure can be effectively suppressed.
According to a fifth aspect of the present invention, there is provided the liquid dispensing apparatus according to the fourth aspect, wherein the negative pressure control valve is constituted by an electropneumatic regulator.

In the present invention, since the negative pressure is controlled by the electropneumatic regulator, there is an effect that the negative pressure can be precisely controlled by automatic control by voltage control.
According to a sixth aspect of the present invention, in the liquid dispensing apparatus according to the third aspect, a negative pressure detection device is provided in a pipe line between the negative pressure control valve and the check valve, and the negative pressure generation is performed. The gist is that the device is controlled in accordance with the pressure value detected by the negative pressure detection device.

  In this invention, the negative pressure maintained in the pipe line between the negative pressure control valve and the check valve can be directly monitored, and the negative pressure generator can generate negative pressure as necessary. There is an effect that efficient control can be performed.

According to a seventh aspect of the present invention, in the liquid dispensing apparatus according to the first to sixth aspects, the negative pressure generating device includes an ejector-type vacuum generator.
In this invention, since the negative pressure generator is configured to include a compact and highly efficient ejector-type vacuum generator, there is an effect that the liquid dispensing apparatus itself can be configured compactly.

  According to an eighth aspect of the present invention, in the liquid dispensing apparatus according to the second to seventh aspects, the syringe 3 side tube communicated with both the negative pressure on-off valve and the pressurization on-off valve. The gist is that a syringe pressure detection device is provided in the path.

  In this invention, since the pressure finally applied to the syringe can be measured, in the case of the screw-type dispense pump 15, since the screw can be started after reaching a desired pressure, more precise discharge control can be performed. There is an effect that can be.

  According to a ninth aspect of the present invention, in the liquid dispensing apparatus according to the second to eighth aspects, the syringe-side pipe line communicated with both the negative pressure on-off valve and the pressurization on-off valve. The gist of the present invention is that an open / close valve for residual pressure that is released to the atmosphere is provided.

In the present invention, the pressure of the syringe can be immediately returned to the normal pressure as necessary, so that there is an effect that replenishment and replacement of liquid and various maintenance can be easily performed.
According to a tenth aspect of the present invention, in the method for controlling a liquid dispensing apparatus according to any one of the first to ninth aspects, the control device operates the negative pressure generating device to operate the negative pressure generator. An accumulator step for reducing the pressure of the pipe line between the pressure on-off valve and the check valve to a negative pressure equal to or lower than a predetermined pressure, the pressure on-off valve is opened, and the negative pressure on-off valve is closed to add a syringe. A step of discharging the liquid while applying pressure, and a step of applying a negative pressure to close the pressurization on-off valve and open the negative pressure on-off valve to apply a negative pressure to the syringe when the discharge step is completed The gist of the control method of the liquid dispensing apparatus is

  In this invention, since the negative pressure can be applied to the syringe immediately after the pressurization to the syringe necessary for efficiently discharging the liquid is completed, the liquid breakage after stopping the discharge of the syringe is improved and the discharge is performed. There is an effect that it is possible to suppress dripping and air entry after stopping.

  According to the present invention, it is an object to provide a liquid constant-quantity discharge device and a control method thereof that can improve liquid drainage after stopping discharge of a nozzle and can suppress dripping and entry of air after stop of discharge.

(First embodiment)
Hereinafter, an embodiment of underfilling by a dispensing apparatus provided with a liquid dispensing apparatus 1 embodying the present invention will be described with reference to FIGS.

FIG. 1 is a substantial view showing a liquid dispensing apparatus 1 in the dispensing apparatus of the present embodiment. FIG. 2 is a pneumatic circuit diagram of the pneumatic circuit of the liquid dispensing apparatus 1.
(Dispensing device) The dispensing device includes a liquid dispensing device 1 including a dispenser 14 for supplying an adhesive material AL, which is an underfill material, to a work W, and a pneumatic circuit 2 for applying a predetermined air pressure to the dispenser 14. In addition, a heater unit that applies heat for controlling the viscosity of the adhesive material AL (not shown), a gantry robot that moves the dispenser 14 to the workpiece W, a transport conveyor that transports the workpiece W, and the like are provided.

  The dispenser 14 includes a syringe 3 and a dispense pump 15. The dispense pump 15 includes a preheating device, an encoder for detecting a coating amount, and a drive circuit for rotating the drive motor, in addition to a coating pump body 15a having a drive motor and a nozzle 15b having a screw pump. Then, the drive motor is driven in accordance with a control signal from the control device 17 to apply a predetermined amount of the adhesive material AL to the workpiece W.

  In this embodiment, since the screw pump is provided, it can be said that the pressure change in the syringe is relatively unaffected, but basically, when the adhesive material AL is discharged, the inside of the syringe is set to a positive pressure, Immediately after completion of discharge, negative pressure is applied. If the inside of the syringe is kept at a positive pressure even after the discharge is finished, the dripping of the adhesive material AL from the nozzle may occur, and the workpiece W may be damaged. Therefore, in the present embodiment, immediately after the discharge of the adhesive material AL is finished, a predetermined negative pressure is applied immediately to improve the liquid drainability after the discharge of the syringe 3 is stopped, and the dripping and the entry of air after the discharge is stopped are suppressed. is doing. However, excessive negative pressure allows air to enter the nozzle, which may cause insufficient discharge of the adhesive material AL and generation of bubbles in the workpiece, so apply negative pressure in the syringe. The case timing, pressure setting, and elapsed time need to be strictly controlled.

  In the present embodiment, a seal plug (not shown) is disposed at the origin position, and the nozzle of the dispenser 14 in a standby state is brought into contact with the seal plug, and the tip portion is blocked. In this case, the pressure in the syringe 3 is atmospheric pressure.

  (Syringe and Surroundings) As shown in FIG. 1, the liquid dispensing apparatus 1 includes a pneumatic circuit 2 that adjusts the pressure in the syringe 3 of the dispenser 14, and connects various devices through a plurality of pipes 21 to 26. Configured.

  (Pneumatic circuit 2) The pneumatic circuit 2 will be described below. An air pressure source device 4 that applies pressure for liquid discharge to the syringe 3 is connected to the pipe line 21 of the air pressure circuit 2. A pressure control valve 11 for pressurization is connected to the pipe line 21. The pressurization on / off valve 6 is connected to the pipeline 22 connected to the other port of the pressurization pressure control valve 11, and is connected to the syringe 3 via the pipeline 23.

  The air pressure source device 4 is also connected to a negative pressure generating on-off valve 16 of the negative pressure generating device 5 via a different pipe line. By opening the negative pressure generating on-off valve 16, a negative pressure is generated. Negative pressure is generated by flowing high-pressure air into the generator 5. The negative pressure generated by the negative pressure generator 5 discharges the air in the pipe line 25 from the pipe line 24 connected thereto through the check valve 8 and applies a negative pressure. The negative pressure in the conduit 25 is detected by the negative pressure detection device 10 provided here. Further, the negative pressure control valve 9 is connected to the other end of the pipe 25, and further connected to the negative pressure on-off valve 7 through a pipe 26 connected to the other port of the negative pressure control valve 9. . The negative pressure on-off valve 7 is connected to a pipe line 23 to which the pressurization on-off valve 6 is connected. Further, a residual pressure on-off valve 13 that is released to the atmosphere is connected to the pipe line 23. That is, the syringe 3, the pressurization on-off valve 6, the negative pressure on-off valve 7, and the residual pressure on-off valve 13 are in communication with each other via the pipe line 23. The syringe 23 is connected to the syringe pressure detecting device 12, and the pressure of the pipeline 23, that is, the pressure of the syringe 3 communicated therewith is detected.

  And as a sensor, the negative pressure detection device 10, the syringe pressure detection device 12, the pressurization on-off valve 6, the negative pressure on-off valve 7, the negative pressure control valve 9, the pressurization pressure control valve 11, the residual pressure on-off valve 13. The negative pressure generating on-off valve 16 is connected to the control device 17 via a predetermined interface.

  The control device 17 is composed of a computer having a well-known CPU, RAM, ROM, and HDD. The controller 17 processes a signal input from a sensor based on a program stored in the HDD, operates an actuator, and this embodiment. The method for controlling the liquid dispensing apparatus is executed.

Next, these devices will be described in detail with reference to the pneumatic circuit diagram of FIG.
The air pressure source device 4 is constituted by, for example, a compressor 41 installed in a factory outside the dispensing device, and compresses air to generate high-pressure air. In addition, it accumulates in an air tank (not shown), the compressed air is cooled, the drain is separated, and pressure fluctuation and pulsation are suppressed. Further, impurities in the compressed air are removed by a main line filter or a dryer.

  Subsequently, an FRL (Filter, Regulator, Lubricator) unit 42 is connected in the vicinity of the use end of the air piping in the factory to which the dispensing apparatus is connected. In the FRL unit 42 of the present embodiment, since the dispensing device is configured with an oil-free device, there is no lubricator, and a pressure gauge, a regulator that is a pressure reducing valve with a relief, and a filter with a manual drain discharger. Consists of filters.

  Then, the air pressure is monitored by the sensor 43 with the pressure switch, and is generally adjusted to 0.5 to 0.7 MPa by the regulator of the FRL unit 42. The oil mist in the air is removed by the manually discharged oil mist separator 44. This air pressure source device 4 includes an on-off valve 45 consisting of a 3-port 2-position valve operated by a detent-fixed lever. When in use, the position is switched by lever operation and communicated with a connection end to pass compressed air, and the lever is operated. The returning operation closes the compressed air line and releases the residual pressure at the end of use to the atmosphere. The sound at this time is muted by a silencer.

  This air pressure source device 4 is provided with two connection ends. A regulator 46 is connected to one connection end and the pressure is reduced to approximately 0.4 MPa. A regulator 47 is connected to the other connection end. Is connected and the pressure is reduced to approximately 0.2 MPa.

  A negative pressure generating on-off valve 16 of the pneumatic circuit 2 of the liquid dispensing apparatus 1 is connected to the use end that has been depressurized to 0.4 MPa. The negative pressure generating on-off valve 16 is composed of a normally closed 3-port 2-position valve capable of electromagnetic pilot operation. When this negative pressure generating on-off valve 16 is opened by electromagnetic operation by the control device 17 (FIG. 1), the compressed air flows into the negative pressure generating device 5.

  In the present embodiment, the negative pressure generator 5 is constituted by an ejector-type vacuum generator. This ejector type vacuum generator converts the pressure energy of the fluid into kinetic energy by injecting the compressed air that has flowed in from the nozzle, thereby increasing the flow velocity of the air. The negative pressure is generated by passing the air through the diffuser. The air that has passed through the diffuser is released to the atmosphere via a silencer.

  The negative pressure generated by the negative pressure generator 5 lowers the pressure in the pipe line 24 connected to a predetermined port of the negative pressure generator 5. A check valve 8 is provided at the other end of the conduit 24. A pipe 25 is provided at the other port of the check valve 8. Since the check valve 8 allows air to flow only in the direction from the pipe 25 to the pipe 24, the negative pressure generated by the negative pressure generator 5 causes the pressure in the pipe 25 to decrease due to the negative pressure in the pipe 24. . Even if the pressure in the pipeline 24 increases in this state, air does not flow from the pipeline 24 to the pipeline 25 due to the function of the check valve 8, and the pressure in the pipeline 25 once lowered increases again. Never do. Accordingly, the conduit 25 has a function as an accumulator that accumulates negative pressure. Further, a negative pressure detection device (pressure gauge) 10 is connected to the pipe line 25, and the pressure in the pipe line 25 is monitored by the control device 17. The control device 17 monitors the pressure in the pipe line 25. If the pressure is lower than the predetermined pressure, the negative pressure generating on-off valve 16 is closed to stop the function of the negative pressure generating device 5. On the other hand, when the pressure in the pipe line 25 is higher than a predetermined pressure, the negative pressure generating on-off valve 16 is opened and the negative pressure generating device 5 is operated to generate a negative pressure.

  A negative pressure control valve 9 is connected to the other end of the conduit 25. The negative pressure control valve 9 is composed of an electropneumatic regulator. The electropneumatic regulator can be adjusted in pressure by an electric signal and can be controlled by the control device 17. The electropneumatic regulator itself includes a computer and a pressure detection device, and can autonomously perform feedback control so as to maintain a specified pressure. For this reason, the negative pressure accumulated in the pipe line 25 is used to autonomously adjust the pressure in the pipe line 26 to a specified constant pressure.

  The other end of the pipeline 26 is connected to the negative pressure on-off valve 7. Further, a pipe line 23 is connected to the other port of the negative pressure on-off valve 7. This negative pressure on-off valve 7 is composed of a normally closed 3-port 2-position valve capable of electromagnetic pilot operation. When the on / off valve 7 for negative pressure is opened by electromagnetic operation by the control device 17 (FIG. 1), the pressure of the pipe line 23 is made negative by the negative pressure of the pipe line 26 maintained at a constant negative pressure. When the air in the pipe line 23 flows into the pipe line 26 and the pressure in the pipe line 26 increases, the negative pressure control valve 9 operates, the air in the pipe line 26 flows into the pipe line 25, and the pipe line 26 has a constant negative pressure. To maintain. At this time, since the pipe line 25 is maintained at a sufficiently low negative pressure, even if the pressure in the pipe line 26 is increased, the negative pressure is maintained almost instantaneously. By maintaining the negative pressure in the pipe line 26, once the negative pressure on-off valve 7 is opened, the pipe line 23 that is immediately communicated is also set to a negative pressure similar to that of the pipe line 26. Further, the pipe line 23 is in a state of always communicating with the syringe 3. Therefore, the pressure in the syringe 3 is instantaneously adjusted to the predetermined negative pressure by the pipe line 23 maintained at the predetermined negative pressure in this way.

  On the other hand, the use end whose pressure has been reduced to 0.2 MPa is connected to the pressure control valve 11 for pressurization of the pneumatic circuit 2 through the pipe line 21. A pipe line 22 is connected to the other port of the pressure control valve 11 for pressurization. The pressurizing pressure control valve 11 is also composed of an electropneumatic regulator. Therefore, it is possible to autonomously control according to the set value by the control device 17 as with the negative pressure control valve 9. For this reason, the positive pressure in the pipe line 21 constantly adjusted by the regulator 47 is used to adjust the pressure in the pipe line 22 to a constant positive pressure.

  The other end of the conduit 22 is connected to the pressurization on-off valve 6. A pipe line 23 is connected to the other port of the pressurizing on-off valve 6. The pressurizing on-off valve 6 is composed of a normally closed 3-port 2-position valve capable of electromagnetic pilot operation. When the pressurizing on-off valve 6 is opened by electromagnetic operation by the control device 17 (FIG. 1), the pressure of the pipe line 23 is made positive by the positive pressure of the pipe line 22 maintained at a constant pressure. When air flows into the pipe line 23 from the pipe line 22 and the pressure in the pipe line 22 decreases, the pressure control valve 11 for pressurization works, the air in the pipe line 21 flows into the pipe line 22, and the pipe line 22 has a constant positive pressure. Maintained. At this time, since the pipe line 21 is maintained at a sufficiently high positive pressure, even if the pressure in the pipe line 22 decreases, the pipe line 21 is maintained at a predetermined positive pressure almost instantaneously. By maintaining the positive pressure of the pipe line 22, once the pressurization on-off valve 6 is opened, the pipe line 23 that is immediately communicated is also set to a positive pressure similar to that of the pipe line 22. Further, the pipe line 23 is in a state of always communicating with the syringe 3. Therefore, the pressure in the syringe 3 is instantaneously adjusted to the predetermined positive pressure by the pipe line 23 maintained at the predetermined positive pressure in this way.

A syringe pressure detection device (pressure gauge) 12 is connected to the pipe line 23, and the pressure in the pipe line 23, that is, the syringe 3 is constantly monitored and a detection signal is sent to the control device 17.
A residual pressure on-off valve 13 is connected to the conduit 23. The residual pressure on-off valve 13 is a normally open 3-port 2-position valve that can be operated by an electromagnetic pilot. While the dispensing process is closed by the control device, when the dispensing process is finished, the solenoid is disconnected, the residual pressure on-off valve 13 is opened by the return spring, and the inside of the syringe 3 is released to the atmospheric pressure.

Next, the operation of the liquid dispensing apparatus 1 of the present embodiment configured as described above will be described along the flowchart of FIG.
In the dispensing device, the syringe 3 of the embodiment stores an adhesive material AL for bonding a semiconductor chip mounted on a substrate for an underfilling process.

  (S1 preheating step) When the power is turned on (start), the syringe 3 is preheated to a predetermined temperature by a preheating mechanism (not shown) to adjust the adhesive material AL to a predetermined viscosity. Further, preheating of the housing of the dispense pump 15 and preheating of the workpiece W are performed by a heater unit (not shown).

  (S2 accumulation process) Up to this point, the dispenser 14 is on standby at the work origin, and the nozzle 15b is closed with a sealing plug. At this time, the residual pressure on-off valve 13 is released, and the inside of the syringe 3 is at atmospheric pressure.

  Further, the on-off valve 45 of the air pressure source device 4 is opened, and compressed air is supplied to the air pressure circuit 2. In the initial state, since the negative pressure detection device 10 detects that the pressure is higher than the predetermined negative pressure, the control device 17 opens the negative pressure generating on-off valve 16. If it does so, a negative pressure will generate | occur | produce in the negative pressure generator 5, and the inside of the pipe lines 24 and 25 will be made into a negative pressure. When the negative pressure is accumulated in the pipe line 25, the negative pressure control valve 9 monitors the pressure in the pipe line 26 and uses the negative pressure in the pipe line 25 to control the pressure in the pipe line 26. It adjusts so that it may become the predetermined negative pressure designated from.

On the other hand, since the compressed air is accumulated in the pipe line 21, the pressure control valve 11 for pressurization adjusts the pipe line 22 to a predetermined pressure by the control device 17 using the compressed air.
(S3 Discharging Process) Next, when the preheating and pressure adjustment of each part are completed, the dispensing process is started. The dispenser 14 is controlled by the control device 17 and moved to a place where the adhesive material needs to be discharged by a gantry robot (not shown).

  Next, the controller 17 instructs the dispense pump 15 to discharge a predetermined amount. At this time, in order to pressurize the inside of the syringe 3 as an aid for discharge from the nozzle 15b, the residual pressure on-off valve 13 is closed and the pressurization on-off valve 6 is opened. At this time, the negative pressure on-off valve 7 is closed. For this reason, the pressure in the pipe line 23, that is, the syringe 3 is maintained at the pressure set by the pressure control valve 11 for pressurization.

  From this state, the dispense pump 15 is driven to discharge a predetermined amount of the adhesive material AL from the nozzle 15b to a predetermined position of the workpiece W. When the rotation of the screw pump is detected by the encoder and an accurate amount of the adhesive material AL is discharged, the screw pump is stopped and the discharge is finished.

  (S4 negative pressure applying step) At this time, even if the screw pump is stopped, the adhesive AL adhered to the tip of the nozzle 15b may drop from the tip of the nozzle 15b, so-called dripping may occur. In particular, since the adhesive material AL has various viscosities depending on the application, some of the adhesive material AL easily adheres to the nozzle tip. Therefore, in the present embodiment, when the discharge of the adhesive material AL is completed, the inside of the syringe 3 is set to a negative pressure, and the adhesive material AL attached to the nozzle tip is pulled back from the nozzle opening.

  This procedure will be described in detail. When the control device 17 detects the rotation of the dispense pump 15 by the encoder and determines that the discharge has ended, the control device 17 immediately closes the pressurization on-off valve 6 and opens the negative pressure on-off valve 7. Then, the pressurized air flows from the pressurized syringe 3 and the conduit 23 communicating with the syringe 3 to the conduit 26 maintained at a negative pressure through the negative pressure on-off valve 7. If it does so, the negative pressure of the pipe line 26 will become weak. When the negative pressure in the pipe line 26 is weakened, the pressure in the pipe line 26 is immediately adjusted to a negative pressure by using the negative pressure accumulated in the pipe line 25 by the negative pressure control valve 9. Since the pipeline 25 has a function as an accumulator in which a large negative pressure is accumulated, a negative pressure can be applied immediately when the pressure in the pipeline 26 rises. Specifically, the air in the syringe 3 passes through the negative pressure on-off valve 7 and the negative pressure control valve 9 and is quickly sucked into the conduit 25 until a predetermined pressure is reached. At this time, since the air pressure in the pipe line 25 is kept sufficiently low, the air pressure in the syringe 3 is instantaneously made negative.

  As described above, the state of the air pressure in the syringe 3 is changed from the pressurized state to the negative pressure state immediately after the discharge of the adhesive material AL is completed. In this case, the negative pressure can be applied without a time lag because a strong negative pressure accumulated in the pipe 25 is used in advance. Therefore, dripping of the adhesive material AL adhering to the nozzle tip can be effectively suppressed. Furthermore, a strong negative pressure is accumulated in the pipe line 25, but in the pipe line 26, the negative pressure control valve 9 adjusts to a predetermined pressure, so that an excessive negative pressure is applied to the syringe 3, Air does not enter the nozzle 15b.

  Then, when performing a discharge process (S3) (S5; NO), the step of S2-S4 is repeated. At this time, when the negative pressure accumulated in the pipe line 25 is weakened, the negative pressure is detected by the negative pressure detecting device 10, and the negative pressure generating on-off valve 16 is opened, and the negative pressure is maintained until the pipe line 25 reaches a predetermined air pressure. Are accumulated (S2).

When all the discharge processes (S3) are completed (S5; YES), an end process is performed.
(S6 Termination Process) In the termination process, the control device 17 terminates the heating, moves the dispenser 14 to the work origin by the gantry robot, and sets the nozzle 15b in the sealing plug provided here. In this way, the tip of the nozzle 15b is closed and sealed. The negative pressure on-off valve 7, the pressurizing on-off valve 6, and the negative pressure generating on-off valve 16 are all closed, and the residual pressure on-off valve 13 is opened. Then, the inside of the syringe 3 is released to atmospheric pressure, but there is no problem such as dripping because there is a tight stopper. Thus, the power is turned off and the process is terminated (END).

In the liquid dispensing apparatus of the above embodiment, the following effects can be obtained.
(1) Since a large negative pressure is always accumulated in the conduit 25 in advance and functions as an accumulator, there is no time lag when the negative pressure starts to be generated for the first time after the negative pressure is required, and immediately in the syringe 3 Has the effect of being able to be negative pressure.

  (2) Further, since the on-off valve 6 for pressurization and the on-off valve 7 for negative pressure are connected to the syringe 3 through the pipe line 23, they can be operated independently without switching to either one, There is an effect that there is no operation delay caused by switching.

(3) In particular, since the check valve 8 can maintain the negative pressure once it can be accumulated in the pipe 25, there is an effect that the negative pressure generator 5 need not always be operated.
(4) Furthermore, since the negative pressure accumulated in the pipe 25 is autonomously adjusted by the negative pressure control valve 9, the nozzle 3 does not apply excessive negative pressure to the syringe 3. There is an effect that it is possible to prevent the suction of air from the tip of the 15b.

  (5) In particular, since the negative pressure control valve 9 is constituted by an electropneumatic regulator, the control device 17 can perform precise control. Moreover, since the air pressure in the syringe 3 is constantly monitored by the syringe pressure detecting device 12, the air pressure in the syringe 3 can be automatically adjusted to an optimum state by the control device 17 even if there is a change. .

  (6) Note that the negative pressure of the conduit 25 as an accumulator is constantly monitored by the control device 17 by the negative pressure detection device 10. If the negative pressure is weakened, the negative pressure generator 5 is operated to accumulate the negative pressure up to a predetermined air pressure. Therefore, there is an effect that a stable negative pressure can be supplied at all times and the negative pressure generating device 5 is not operated wastefully.

(7) Since the negative pressure generator 5 includes a compact and highly efficient ejector-type vacuum generator, there is an effect that the liquid metering device 1 itself can be configured compactly.
(8) The syringe pressure detection device 12 is disposed in the pipe line 23 communicating with the syringe 3, and the control device 17 constantly monitors the air pressure in the syringe 3 by the syringe pressure detection device 12. In this invention, since the pressure finally applied to the syringe can be measured, in the case of the screw-type dispense pump 15, since the screw can start rotating after reaching the desired pressure, more precise discharge control can be achieved. There is an effect.

  (9) In addition, when the on-off valve 13 for residual pressure is provided and not in the dispensing process, the inside of the syringe 3 is released to atmospheric pressure, and the tip of the nozzle 15b is closed with a tight plug at the work origin. Therefore, useless energy is not used outside the dispensing process.

In addition, you may change the said embodiment as follows.
In the present embodiment, a simple configuration is obtained by causing the space of the pipeline 25 to function as an accumulator, but the length and thickness are appropriately selected according to the required specifications. Further, if a large negative pressure is required, it does not prevent further provision of a tank type accumulator.

  In the present embodiment, the liquid dispensing apparatus 1 is described by taking an underfill dispense as an example. However, a solder dot dispense, a dam and fill dispense, an encapsulation dispense, a chip-on-board seal using a dispenser. It can be widely used for dispensing, conductive adhesive dispensing, UV adhesive dispensing, and the like.

For example, a thermosetting adhesive is preferably used as the underfill material, but the underfill material is not limited thereto, and a thermosetting or thermoplastic resin may be used.
The negative pressure generator 5 is composed of an ejector vacuum generator, but may be composed of a vacuum pump instead.

  ○ In this embodiment, a screw pump is adopted. However, in the case of a pressure pump, the pressure in the syringe 3 is still important, and more strict control is required. Therefore, it can be suitably applied without delay in control.

O Needless to say, appropriate air pressures such as the syringe 3 and the pipeline 25 are appropriately changed according to the purpose.
○ The pressurizing on-off valve 6 and the negative-pressure on-off valve 7 do not need to be operated alternatively, and can be used to overlap or close simultaneously by air flow. Is. Such an operation is difficult with a switching valve, and more efficient operation is possible.

The present invention is not limited to the underfill material, but is a liquid fixed amount discharge device that discharges liquid precisely and is widely applicable to supply of fixed amounts of chemicals.
The flowchart of the embodiment shows an example of work, and the present invention is not limited to the order.

  It goes without saying that the present invention can be omitted, added, modified, and improved by those skilled in the art without departing from the scope of the claims.

FIG. 3 is a schematic diagram of a liquid dispensing apparatus in the dispensing apparatus of the present embodiment. FIG. 3 is a pneumatic circuit diagram of a liquid dispensing device in the dispensing device of the present embodiment. The flowchart figure which shows the control method of the liquid fixed quantity discharge apparatus in the dispensing apparatus of this embodiment. FIG. 6 is a pneumatic circuit diagram showing a liquid ejection device of the prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Liquid fixed amount discharge device, 2 ... Pneumatic circuit, 3 ... Syringe, 4 ... Air pressure source device, 5 ... Negative pressure generator, 6 ... Pressurization on-off valve, 7 ... Negative pressure on-off valve, 8 ... Check valve, 9 DESCRIPTION OF SYMBOLS ... Negative pressure control valve, 10 ... Negative pressure detection apparatus, 11 ... Pressure control apparatus for pressurization, 12 ... Syringe pressure detection apparatus, 13 ... Residual pressure on-off valve, 14 ... Dispenser, 15 ... Dispense pump, 17 ... Control apparatus, 21, 22, 23, 24, 25, 26 ... conduits.

Claims (10)

A syringe for storing the liquid discharged from the nozzle;
An air pressure source device for applying pressure for liquid discharge to the syringe;
A negative pressure generator for applying a negative pressure for liquid holding to the syringe;
An on-off valve for pressurization that opens and closes a pipe line disposed between the syringe and the air pressure source device;
A negative pressure on-off valve for opening and closing a pipe line disposed between the syringe and the negative pressure generator;
A check valve disposed in a pipe line between the negative pressure generating device and the negative pressure on-off valve, and maintaining a negative pressure on the pipe on the negative pressure on-off valve side;
A liquid dispensing apparatus characterized in that a pressure in a pipe line between the negative pressure on-off valve and the check valve is maintained at a negative pressure equal to or lower than a predetermined pressure. 2. The liquid constant rate dispensing apparatus according to claim 1, wherein a pipe line connected to the negative pressure on-off valve and a pipe line connected to the pressurization on-off valve communicate with each other. The liquid dispensing apparatus according to claim 1 or 2, further comprising a negative pressure control valve between the negative pressure on-off valve and the check valve. A pressure control valve for pressurization is provided between the pressurization on-off valve and the air pressure source device;
The liquid dispensing apparatus according to claim 3, wherein the pressure control valve for pressurization is constituted by an electropneumatic regulator. 5. The liquid dispensing apparatus according to claim 4, wherein the negative pressure control valve comprises an electropneumatic regulator. A negative pressure detection device is provided in a pipe line between the negative pressure control valve and the check valve,
4. The liquid dispensing apparatus according to claim 3, wherein the negative pressure generating device is controlled according to a pressure value detected by the negative pressure detecting device. The liquid dispensing apparatus according to any one of claims 1 to 6, wherein the negative pressure generating device includes an ejector-type vacuum generator. The liquid according to any one of claims 2 to 7, wherein a syringe pressure detection device is provided in a syringe-side conduit communicated with both the negative pressure on-off valve and the pressurization on-off valve. Constant discharge device. 9. A residual pressure on-off valve for releasing to the atmosphere is provided in a syringe-side conduit communicated with both the negative pressure on-off valve and the pressurization on-off valve. Liquid dispensing apparatus described in 1. A control method for a liquid dispensing apparatus according to any one of claims 1 to 9, wherein the control device comprises:
An accumulating step of operating the negative pressure generating device to reduce the pressure of the pipe line between the negative pressure on-off valve and the check valve to a negative pressure equal to or lower than a predetermined pressure;
A step of discharging the liquid while opening the pressure on-off valve and closing the negative pressure on-off valve to pressurize the syringe; and
When the discharge step is completed, the liquid quantification is performed by closing the pressurization on-off valve and opening the negative pressure on-off valve to apply a negative pressure to the syringe. Discharge device control method.

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