Flux supply device and flux supply method

Abstract

This flux supply device comprises: a flux pot that retains a flux supplied from a flux cartridge having stored therein the flux; and a suction pump that keeps a space inside the flux cartridge in a negative pressure state in order to cut off the supply of the flux from the flux cartridge to the flux pot. Accordingly, by keeping the space inside the flux cartridge in the negative pressure state during the supply stop period of the flux, it is possible to prevent the occurrence of dripping due to leakage of the flux from an ejection port through which the flux is ejected from the flux cartridge to the flux pot.

Description

Flux supplying device and flux supplying method

[0001] The present invention relates to a flux supplying device and a flux supplying method.

[0002] Flux applicators that apply liquid flux to packaged components, such as semiconductor chips, have been put to practical use. Flux applicators often incorporate a flux supply device that extracts and supplies flux from a replaceable cartridge containing the flux. The flux supply device uses a pump to supply the flux from the cartridge to a coating unit (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2000-202621

[0004] The amount of flux to be applied to a package is strictly defined. For example, when the package is immersed in flux filled in an immersion bath, the amount of flux supplied to the immersion bath is also strictly controlled. In other words, the amount of flux dispensed from the cartridge must be precise relative to the specified supply amount. Furthermore, although different fluxes may be applied depending on the package, it is undesirable for a flux supply device to drip during supply stop periods, regardless of the type of flux used.

[0005] The present invention has been made to solve such problems, and provides a flux supplying device and the like that can supply flux accurately at a specified supply amount without causing dripping during periods when the supply of flux is stopped.

[0006] A flux supplying device according to a first aspect of the present invention includes a flux pot in which flux is supplied from a flux cartridge containing the flux and stored, and a suction pump that maintains a negative pressure in a space within the flux cartridge to block the supply of the flux from the flux cartridge to the flux spot.

[0007] A flux supplying method according to a second aspect of the present invention includes a supplying step of supplying the flux from a flux cartridge containing the flux to a flux spot storing the flux, and a blocking step of blocking the supply of the flux from the flux cartridge to the flux spot by operating a suction pump to create a negative pressure in the space within the flux cartridge.

[0008] According to the present invention, by maintaining a negative pressure in the space within the flux cartridge during a period when the supply of flux is stopped, it is possible to prevent the flux from leaking from the outlet through which the flux is discharged from the flux cartridge to the flux spot, thereby preventing dripping. Therefore, the present invention can provide a flux supply device and the like that can accurately supply a specified amount of flux without causing dripping during a period when the supply of flux is stopped.

[0009] It is a diagram showing the overall configuration of the flux supply device according to the present embodiment. It is a diagram showing the system configuration of the flux supply device. It is a flowchart explaining the processing procedure of the arithmetic processing unit.

[0010] The present invention will be described below through embodiments of the invention, but the invention according to the claims is not limited to the following embodiments. Furthermore, not all of the configurations described in the embodiments are necessarily essential as means for solving the problems.

[0011] 1 is a diagram schematically illustrating the overall configuration of a flux supplying device 100 according to this embodiment. The flux supplying device 100 supplies flux contained in a flux cartridge 200 to a flux application device. The flux supplying device 100 may be incorporated into the flux application device as an independent unit, or may be configured as a part of the flux application device.

[0012] The flux supply device 100 supplies the flux FX contained in the attached replaceable flux cartridge 200 to the flux application device. That is, when the flux cartridge 200 is attached, it becomes possible to supply the flux FX, and when the contained flux FX is consumed or when a different type of flux FX is to be supplied, the flux cartridge 200 is replaced with a new flux cartridge 200 suited to the purpose.

[0013] The flux supply device 100 mainly includes a flux spot 110, a pressurized pump 120, a suction pump 130, a stage 150, a processing unit 160, and a moving mechanism 170. The flux spot 110 serves as a flux relay function of storing the flux FX supplied from the flux cartridge 200 and supplying the flux FX to an immersion tank 151 provided as a recess on the surface of the stage 150.

[0014] Specifically, the flux pot 110 includes a storage tank 111, which is an internal space whose upper part is open to the surrounding space, and the flux FX supplied from the flux cartridge 200 is temporarily stored in the storage tank 111. Since the stored flux FX is released to atmospheric pressure in this manner, it is easy for an operator to perform maintenance work, such as switching to a different type of flux FX.

[0015] The flux spot 110 also includes a detector 113 that detects the amount of flux FX stored in the storage tank 111. The detector 113 is, for example, a photosensor array installed along the depth direction of the storage tank 111, and detects the amount of stored flux FX by identifying the liquid surface of the flux FX according to the position at which reflected light is received. The detector 113 may have any configuration as long as it includes a sensor that can detect the amount of stored flux FX. A detection signal from the detector 113 is sent to the calculation processing unit 160.

[0016] The flux pot 110 includes a control valve 114 on the bottom surface of a storage tank 111. The control valve 114 is opened and closed by an open / close signal from the calculation processing unit 160. When the control valve 114 is opened, the flux FX stored in the storage tank 111 is discharged to the outside space due to the action of gravity. When the control valve 114 is maintained in a closed state, the flux FX stored in the storage tank 111 does not leak to the outside space.

[0017] The pressurizing pump 120 takes in air from the surrounding space through the air intake 121 and sends it into the internal space 210 of the flux cartridge 200, thereby creating a positive pressure in the gas phase 210b and pushing down the liquid phase 210a, which is the contained flux FX. The pressurizing pump 120 operates in response to a pressurizing signal from the arithmetic processing unit 160.

[0018] The suction pump 130 is a pump that has the function of sucking air from the gas phase 210b of the internal space 210 and discharging it from the exhaust port 131, thereby maintaining the gas phase 210b in a negative pressure state and keeping the contained flux FX in the internal space 210. The suction pump 130 operates in response to a suction signal from the calculation processing unit 160.

[0019] The pressurizing pump 120, the suction pump 130, and the flux cartridge 200 are connected to one another via a three-way valve 145. Specifically, the pressurizing pump 120 and the three-way valve 145 are connected by a first air tube 141, the suction pump 130 and the three-way valve 145 are connected by a second air tube 142, and the three-way valve 145 and a first joint 201 communicating with the gas phase 210b of the flux cartridge 200 are connected by a third air tube 143. That is, the connecting pipe connecting the pressurizing pump 120 and the flux cartridge 200 and the connecting pipe connecting the suction pump 130 and the flux cartridge 200 share a portion of the same pipe on the side of the first joint 201 connected to the flux cartridge 200. With this configuration, even if a flux cartridge has only one joint communicating with the gas phase, the suction pump 130 can be connected to both the pressurizing pump 120 and the flux cartridge 200. It is preferable that the third air tube 143 be provided with a detachment mechanism at the end connected to the first joint 201 to facilitate attachment and detachment to and from the first joint 201 .

[0020] The internal valve of the three-way valve 145 is displaced so that the first air tube 141 and the third air tube 143 pass through it while the pressurizing pump 120 is operating, and is displaced so that the second air tube 142 and the third air tube 143 pass through it while the suction pump 130 is operating. The first air tube 141, the second air tube 142, and the third air tube 143 may be made of, for example, polyvinyl chloride resin piping that is suppressed from expanding and contracting due to the flow of air.

[0021] The flux cartridge 200 includes a first joint 201 communicating with the gas phase 210b and a second joint 202 communicating with the liquid phase 210a. When the flux spot 110 is placed at a supply position where it receives a supply of flux FX, an outlet 148 is provided at a position facing the storage tank 111. One end of a flux tube 147 is connected to the outlet 148, and the other end is connected to the second joint 202. It is preferable that the flux tube 147 be provided with a detachment mechanism at the other end connected to the second joint 202, which facilitates attachment and detachment to and from the second joint 202.

[0022] Furthermore, the flux tube 147 is preferably a pipe made of a transparent resin. Although it is depicted as a relatively short, straight tube in FIG. 1, the attachment position of the flux cartridge 200 and the supply position of the flux spot 110 are often separated from each other, and the relatively long flux tube 147 may be arranged in a curved manner. In particular, in such cases, if the flux tube 147 is made of a transparent resin, it is effective because the operator can check whether the flux FX is flowing smoothly inside the tube.

[0023] The flux cartridge 200 is detachable from the holder 180 provided in the flux supply device 100. When a new flux cartridge 200 is attached to the holder 180, one end of the third air tube 143 is connected to the first joint 201 of the new flux cartridge 200, and one end of the flux tube 147 is connected to the second joint 202 of the new flux cartridge 200. Conversely, when the flux cartridge 200 is removed from the holder, one end of the third air tube 143 is detached from the first joint 201, and one end of the flux tube 147 is detached from the second joint 202.

[0024] The stage 150 is provided with an immersion tank 151 dug into a portion of its surface as a recess. Although FIG. 1 shows only one immersion tank 151 provided on the stage 150, multiple immersion tanks 151 may be provided. The immersion tank 151 is filled with flux FX supplied from the flux spot 110. The flux application device holds and transports the package to be applied, and immerses the application surface of the package in the flux FX filled in the immersion tank 151. After being pulled up, the application surface is dried and then transported to a predetermined position.

[0025] The moving mechanism 170 is a mechanism for moving the flux spot 110 back and forth between a filling position where the immersion tank 151 is filled with flux FX and a supply position where the flux FX is supplied from the flux cartridge 200. The moving mechanism 170 includes, for example, a motor as an actuator and a gear train as a power transmission mechanism, and moves the flux spot 110 to a target position upon receiving a drive signal from the arithmetic processing unit 160. In Fig. 1, the supply position where the flux spot 110 storage tank 111 is located directly below the discharge port 148 is indicated by a solid line, and the filling position where the flux spot 110 control valve 114 is located directly above the immersion tank 151 is indicated by a dotted line.

[0026] 2 is a diagram showing the system configuration of the flux supply device 100. The control system of the flux supply device 100 mainly comprises an arithmetic processing unit 160, a pressurizing pump 120, a suction pump 130, a detection unit 113, a control valve 114, and a movement mechanism 170. The arithmetic processing unit 160 is a processor (CPU: Central Processing Unit) that controls the flux supply device 100 and executes programs. The processor may be configured to work in conjunction with an arithmetic processing chip such as an ASIC (Application Specific Integrated Circuit) or a GPU (Graphics Processing Unit).

[0027] The arithmetic processing unit 160 also serves as a functional calculation unit that executes various calculations in response to processing instructed by the flux supply program. Specifically, the arithmetic processing unit 160 can function as a supply control unit 161 and a drive control unit 162. The supply control unit 161 sends a pressurization signal to the pressurization pump 120 to operate it, thereby putting the gas phase 210b into a positive pressure state and discharging the flux FX in the flux cartridge 200 from the outlet 148. In addition, the supply control unit 161 sends a suction signal to the suction pump 130 to operate it, thereby putting the gas phase 210b into a negative pressure state and blocking the flux FX in the flux cartridge 200 from flowing out from the outlet 148.

[0028] The supply control unit 161 also sends an open / close signal to the control valve 114 to operate it, thereby transferring the flux FX from the storage tank 111 to the immersion tank 151 or blocking the flow. The supply control unit 161 also receives a detection signal from the detection unit 113 to determine the amount of flux FX stored in the storage tank 111, and when the amount of stored flux falls below a preset threshold, for example, the supply control unit 161 cooperates with the drive control unit 162 to start a flux supply process for supplying the flux FX to the storage tank 111.

[0029] The drive control unit 162 sends a drive signal to the moving mechanism 170 to drive the actuator of the moving mechanism, thereby moving the flux spot 110 to a target position on the stage 150. When the drive control unit 162 receives a command from the supply control unit 161 to start the flux supply process, it moves the flux spot 110 to a supply position where it receives a supply of flux FX from the flux cartridge 200. When the drive control unit 162 receives a notification from the control unit of the flux application device that a preset number of mounting assemblies have been immersed in the immersion tank 151, it moves the flux spot 110 to a filling position where the flux FX is filled into the immersion tank 151.

[0030] According to the flux supply device 100 configured as described above, when supplying the flux FX to the flux spot 110, the gas phase 210b of the flux cartridge 200 is immediately switched to a negative pressure state upon completion of supply. This prevents dripping even when handling fluxes of different viscosities. Therefore, an accurate amount of flux FX can be supplied to the flux spot 110 in accordance with the specified supply amount. Furthermore, even when the flux spot 110 is not present at the supply position, the suction pump 130 can be operated to maintain the gas phase 210b of the flux cartridge 200 in a negative pressure state, preventing dripping and therefore avoiding contamination of the stage 150.

[0031] Next, the processing procedure of the arithmetic processing unit 160 when executing a flux supply process for supplying the flux FX from the flux cartridge 200 to the storage tank 111 of the flux spot 110 and a flux filling process for filling the flux FX from the storage tank 111 into the immersion tank 151 will be described. Fig. 3 is a flow diagram for explaining the processing procedure of the arithmetic processing unit 160. The illustrated flow starts when the flux supply process is started and the flux spot 110 is moved to the supply position by the moving mechanism 170.

[0032] In step S101, the supply control unit 161 stops the suction signal that has been sent to the suction pump 130, thereby stopping the operation of the suction pump 130. Subsequently, in step S102, the supply control unit 161 sends a pressurization signal to the pressurization pump 120, thereby starting the operation of the pressurization pump 120. By switching the pump operation in this manner, the gas phase 210b of the flux cartridge 200 is converted to a positive pressure state, and the flux FX is discharged from the discharge port 148.

[0033] In step S103, the supply control unit 161 acquires a detection signal from the detection unit 113 and detects the amount of flux FX stored in the storage tank 111. Then, in step S104, it determines whether the amount has increased to a preset amount, and if it determines that the amount has not increased, it returns to step S103 as supply is incomplete. If it determines that the amount has increased, it proceeds to step S105 as supply is complete.

[0034] When the supply control unit 161 proceeds to step S105, it stops the pressurization signal that it has been sending to the pressurization pump 120, thereby stopping the operation of the pressurization pump 120. Subsequently, in step S106, it sends a suction signal to the suction pump 130, thereby starting the operation of the suction pump 130. By switching the pump operation in this way, the gas phase 210b of the flux cartridge 200 is converted to a negative pressure state, and the outflow of the flux FX from the discharge port 148 is blocked, thereby completing the flux supply process.

[0035] When the drive control unit 162 receives an instruction to start the flux filling process, in step S107, it moves the flux spot 110 to the filling position by sending a drive signal to the moving mechanism 170. When the flux spot 110 reaches the filling position, in step S108, the supply control unit 161 sends an open signal to the control valve 114 to transition it to an open state.

[0036] In step S109, the supply control unit 161 acquires a detection signal from the detection unit 113 and detects the amount of flux FX stored in the storage tank 111. Then, in step S110, it determines whether the amount has decreased to a preset amount, and if it determines that the amount has not decreased, it determines that filling is incomplete and returns to step S109. If it determines that the amount has decreased, it determines that filling is complete and proceeds to step S111.

[0037] When the supply control unit 161 proceeds to step S111, it sends a close signal to the control valve 114 to transition it to a closed state. Subsequently, in step S112, the drive control unit 162 sends a drive signal to the moving mechanism 170 to move the flux spot 110 to the supply position, thereby completing the series of processes. As described above, while the flux spot 110 is not present at the supply position, the supply control unit 161 sends a suction signal to the suction pump 130 to maintain the gas phase 210b of the flux cartridge 200 in a negative pressure state.

[0038] The flux supply device 100 described above includes the pressurized pump 120 and the suction pump 130, but a single pump may be used to switch between exhaust and intake. The discharge of the flux FX from the flux cartridge 200 is not limited to the configuration in which the pressurized pump 120 is operated to convert the gas phase 210b to a positive pressure state. Monitoring the amount of flux FX supplied from the flux cartridge 200 to the storage tank 111 and the amount of flux FX filled from the storage tank 111 to the immersion tank 151 are not limited to the configuration using the detection unit 113. For example, a simpler configuration may be adopted in which the filling amount is kept constant by determining the opening time of the control valve 114.

[0039] DESCRIPTION OF SYMBOLS 100...Flux supply device, 110...Flux pot, 111...Storage tank, 113...Detection unit, 114...Control valve, 120...Pressurization pump, 121...Intake port, 130...Suction pump, 131...Exhaust port, 141...First air tube, 142...Second air tube, 143...Third air tube, 145...Three-way valve, 147...Flux tube, 148...Discharge port, 150...Stage, 151...Immersion tank, 160...Calculation processing unit, 161...Supply control unit, 162...Drive control unit, 170...Moving mechanism, 180...Holder, 200...Flux cartridge, 201...First joint, 202...Second joint, 210...Internal space, 210a...Liquid phase, 210b...Gas phase

Claims

1. A flux supplying device comprising: a flux pot in which flux is supplied from a flux cartridge containing the flux and stored; and a suction pump that maintains a negative pressure in a space within the flux cartridge in order to cut off the supply of the flux from the flux cartridge to the flux pot.

2. A flux supplying device according to claim 1, further comprising a pressure pump for creating a positive pressure in said space in order to supply said flux from said flux cartridge to said flux spot.

3. The flux supply device according to claim 2, wherein a pipe connecting the suction pump and the flux cartridge and a pipe connecting the pressure pump and the flux cartridge share a portion with each other on the side connected to the flux cartridge.

4. The flux supplying device according to claim 1, wherein said suction pump releases the negative pressure in said space in order to supply said flux from said flux cartridge to said flux spot.

5. A flux supplying device as claimed in claim 1, wherein the flux pot has a detection unit which detects the amount of the supplied flux stored therein, and the flux is supplied from the flux cartridge to the flux spot based on the output of the detection unit.

6. The flux supplying device according to claim 1, wherein the flux stored in the flux pot is released to atmospheric pressure.

7. The flux supplying device according to claim 1, wherein a pipe connected to said flux cartridge and supplying said flux to said flux pot is made of a transparent resin.

8. A flux supply device as described in claim 1, comprising: a stage provided with a recess for immersing a mounting body to be coated with the flux in the flux; and a moving mechanism for moving the flux spot back and forth between a filling position for filling the recess with the flux from the flux spot and a supply position for supplying the flux from the flux cartridge to the flux spot, wherein the suction pump maintains a negative pressure in the space within the flux cartridge at least while the flux spot is not present at the supply position.

9. A flux supplying method comprising: a supplying step of supplying a flux from a flux cartridge containing the flux to a flux pot for storing the flux; and a blocking step of blocking the supply of the flux from the flux cartridge to the flux spot by operating a suction pump to create a negative pressure in the space within the flux cartridge.

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