JPH1065325A - Automatic supply method and device for solder paste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a proper amount of solder supplying to each junction position on a substrate by stopping discharges of solder paste, in response to what detected weight increase amount of a substrate attains with respect to a scheduled supply weight. SOLUTION: When supply of solder paste to a junction position on a circuit board 4 is started form a discharge nozzle 1a of a dispenser 1, a control device 7 detects an amount of weight increase for a substrate by an electronic balance 3, based on a substrate weight at the time of start of solder paste supply, and when it attains to a scheduled supply weight which is stored in a table, a specified command is given to a discharge adjustment mechanism 6. Then, the discharge adjustment mechanism 6 starts, and the supply of solder paste is stopped. Since this motion is repeated for a junction place at each pattern number, a proper amount of solder paste can be accurately supplied to each junction place.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for automatically supplying an appropriate amount of solder paste to an intended junction on a printed wiring board by using an injection type dispenser. More particularly, the present invention relates to an automatic solder paste supply method and apparatus which controls the start and stop of solder supply while accurately grasping the amount of supplied solder using a feedback method.

[0002]

2. Description of the Related Art In recent years, environmental pollution by lead has been becoming a problem in various industrial fields.
Lead contained in solder has been regarded as a problem. As a solution to such a problem, while minimizing the amount of surplus solder discarded at the time of manufacturing the component mounting board, we aim to optimize the amount of solder supplied to each joint on the board, thereby reducing It is conceivable to reduce the amount of eluted lead as much as possible.

Conventionally, as a method of manufacturing a component mounting board on which surface mounting components are mounted, a solder supply method using a screen printing technique has been adopted. In this solder supply method, as shown in FIG. 6, a screen mask b is overlapped with an appropriate gap provided on a circuit board a, and a solder paste c is applied on the screen mask b with a squeegee d.
Then, the solder paste c extruded from the opening e of the screen mask b is transferred to a portion to be joined on the circuit board a. FIG.
(A) is a schematic top view of the screen printing machine, FIG.
(B) is the same side sectional view, and f is a print mask frame.

According to such a solder supply method, the supply amount of the solder paste to each joint is controlled according to the accuracy of the screen mask, so that an appropriate amount of solder paste is supplied to each joint without waste. can do. On the other hand, a large amount of solder paste is always left on the screen mask b due to the transfer principle of pushing out the solder paste c from the opening e while rubbing with the squeegee d, and this kind of solder paste deteriorates with time. As a result, there is a problem that a large amount of solder paste is wasted.

[0005] As a method of manufacturing a component mounting board on which surface mounting components are mounted, a solder supply method using a dispenser, which is an injection type viscous fluid supply device, is also known. According to such a solder supply method, it is possible to reduce the amount of waste solder paste due to its property that only the used amount is injected. On the other hand,
It is very difficult to control the amount of solder paste injected from the dispenser with high precision by hand, and as a result, the amount of solder paste supplied varies at each joint, making it difficult to optimize the amount of solder supplied. There is.

[0006]

As described above, in the method of supplying the solder paste, the method of supplying the solder paste by using the screen printing technique has a problem in terms of optimizing the amount of the supplied solder. Although effective, a large amount of solder paste is discarded wastefully, which poses a problem of environmental pollution due to solder discarded at the manufacturing stage. On the other hand, when the solder paste is supplied by using a dispenser, there is little waste of the solder paste in the manufacturing stage, but it is difficult to control the injection amount. there were.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to minimize the amount of excess solder discarded at the time of manufacturing a component mounting board and to reduce the amount of each solder on the board. It is an object of the present invention to provide a method and an apparatus for automatically supplying a solder paste that optimizes the amount of solder supplied to a joint portion and thereby reduces the amount of lead eluted into the environment after product disposal as much as possible.

[0008]

According to a first aspect of the present invention, there is provided an apparatus for supplying an appropriate amount of solder paste to a joint on a substrate by an injection type dispenser. Storage means for storing the expected solder paste supply weight for each of the above joints, and a trace weight detection means for detecting an increase in the weight of the board due to the supply of the solder paste to the joints on the board, Discharging of the solder paste from the solder paste discharge nozzle of the dispenser is started, and in response to the board weight increment detected by the trace weight detecting means reaching the scheduled supply weight stored in the storage means, the solder paste is discharged. And a control means for stopping the discharge of the paste.

In the present invention, the stop of the discharge of the solder paste from the dispenser is controlled by detecting and feeding back the weight increase on the substrate side due to the supply of the solder paste. Here, the "micro weight detection means" could be realized using, for example, an electronic balance or the like.

According to a second aspect of the present invention, there is provided an apparatus for supplying an appropriate amount of solder paste to a joint portion on a substrate by an injection type dispenser. Storage means for storing the expected solder paste supply weight, a minute weight detection means for detecting weight loss of the dispenser due to the supply of the solder paste to the joint on the substrate, and a solder paste for the dispenser. Discharging of the solder paste from the discharge nozzle is started, and discharging of the solder paste is performed in response to the dispenser weight decrease detected by the trace weight detecting means reaching the scheduled supply weight stored in the storage means. And a control means for stopping the solder paste.

According to the second aspect of the present invention, the stop of the discharge of the solder paste from the dispenser is controlled by detecting and feeding back the weight loss on the dispenser side due to the supply of the solder paste. here,
The “micro weight detection means” could be realized using, for example, an electronic balance or the like.

According to a third aspect of the present invention, there is provided an apparatus for supplying an appropriate amount of solder paste to a joint on a substrate by an injection type dispenser, wherein Storage means for storing a predetermined solder paste supply volume, a small volume detection means for detecting a decrease in solder paste volume in the dispenser due to the supply of the solder paste to the joint on the substrate, and the dispenser Starting the discharge of the solder paste from the solder paste discharge nozzle, and responding to the fact that the solder paste volume decrease detected by the minute volume detection means has reached the scheduled supply volume stored in the storage means, And a control means for stopping the discharge of the paste.

According to the third aspect of the present invention, by detecting and feeding back the volume decrease of the solder paste on the dispenser side due to the supply of the solder paste, the stop of the discharge of the solder paste from the dispenser is controlled. I have. Here, as the "micro volume detection means", for example,
It could be realized using a resistance-measuring level meter or the like.

According to a fourth aspect of the present invention, there is provided a method for supplying a proper amount of solder paste to a joint on a substrate by an injection type dispenser, wherein the solder paste is discharged from a solder paste discharge port of the dispenser. Starting the discharge of the solder paste, detecting the increase in the board weight due to the supply of the solder paste onto the board by the discharge, and detecting the detected board weight increase in the solder paste at the joint. Stopping the discharge of the solder paste in response to the supply weight being reached.

According to a fifth aspect of the present invention, there is provided a method for supplying an appropriate amount of solder paste to a joint on a substrate by an injection type dispenser, wherein the solder paste is discharged from a solder paste discharge port of the dispenser. Starting the discharge of the solder paste, detecting the weight loss of the dispenser due to the discharge of the solder paste, and the detected weight loss of the dispenser has reached the expected solder paste supply weight at the joint. Stopping the discharge of the solder paste in response to the method.

The invention according to claim 6 of this application is a method for supplying an appropriate amount of solder paste to a joint on a substrate by an injection type dispenser, wherein the solder paste is supplied from a solder paste discharge port of the dispenser. Starting the discharge of the solder paste; detecting a decrease in the volume of the solder paste in the dispenser due to the discharge; and detecting the decrease in the volume of the solder paste that has reached a predetermined solder paste supply volume at the joint. Stopping the discharge of the solder paste in response to the operation.

According to the invention described in each of these claims, it becomes possible to accurately supply an appropriate amount of solder paste to the joint on the substrate by the injection type dispenser.

[0018]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

First, a first embodiment of a method and an apparatus for automatically supplying solder paste according to the present invention will be described with reference to FIGS.

In FIG. 1, reference numeral 1 denotes an injection type dispenser for discharging a solder paste 2 filled therein from a discharge nozzle 1a, 3 an electronic balance which is located below the dispenser 1 and functions as a minute weight detecting means, Reference numeral 4 denotes a circuit board mounted on a horizontal stage 3a of the electronic balance 3 and having a plurality of joints specified by a pattern number described later on its upper surface, and 5 is supplied to one of the joints on the circuit board 4. Solder paste.

Although not shown, the dispenser 1
Between the discharge nozzle 1a and each joint of the circuit board 4
A three-axis relative positioning mechanism for positioning the two along the XYZ axes is provided. By the operation of a separately provided positioning control device, an arbitrary pattern number can be designated,
The discharge nozzle 1a of the dispenser 1 can be positioned with respect to the joint specified by the pattern number.

Reference numeral 6 denotes a discharge adjusting mechanism for starting and stopping the discharge of the solder paste from the discharge nozzle 1a of the dispenser 1, and 7 operates the discharge adjusting mechanism 6 based on a signal from the electronic balance 3 which is a minute weight detecting means. This is a control device for controlling the start and stop of the discharge of the solder paste.

The control device 7 is constituted by a microcomputer or the like, and its internal memory stores a table having the contents shown in FIG. This table stores the expected supply weight of the solder paste for each pattern number. Here, the “each pattern number” is a number assigned to each joint on the circuit board 4. Since the expected supply weight of the solder paste usually differs depending on the size of the joint, the unique expected supply weight for each individual joint is stored in this table.

Next, the operation of the automatic solder paste supply device having the above configuration will be described. When the pattern number of the joint is specified, the discharge nozzle 1a of the dispenser 1 is positioned above the joint specified by the pattern number by the operation of a three-axis relative positioning mechanism (not shown).
Then, upon receiving a command from the control device 7, the discharge adjusting mechanism 6
Is activated, and supply of the solder paste from the discharge nozzle 1a of the dispenser 1 to the corresponding joint on the circuit board 4 is started.

When the supply of the solder paste is started, the total weight of the circuit board 4 is increased by a small amount, though small. The weight of the circuit board 4 is measured by the electronic balance 3 constituting a minute weight detecting means, and the measured value is sent to the control device 7.

The control device 7 calculates the weight increment based on the substrate weight at the start of the supply of the solder paste to the joint, and determines when the weight increment reaches the scheduled supply weight stored in the table shown in FIG. Then, a predetermined command is given to the discharge adjusting mechanism 6. Then, the discharge adjusting mechanism 6 operates, and the supply of the solder paste from the discharge nozzle 1a of the dispenser 1 to the joint on the circuit board 4 is stopped.

As a result of the above operation being repeated for the joints of each pattern number, it becomes possible to supply an appropriate amount of solder paste to each joint accurately.

Next, a second embodiment of a method and an apparatus for automatically supplying solder paste according to the present invention will be described with reference to FIG.

In FIG. 3, reference numeral 1 denotes an injection type dispenser for discharging the solder paste 2 filled therein from the discharge nozzle 1a, 10 denotes a horizontal stage located below the dispenser 1, and 4 denotes a horizontal stage mounted on the horizontal stage 10. The circuit board 5 which is placed and has on its upper surface a plurality of joints specified by a pattern number to be described later is solder paste supplied to one of the joints on the circuit board 4.

Although not shown, even in this example, a three-axis relative position between the discharge nozzle 1a of the dispenser 1 and each joint of the circuit board 4 for positioning them along the XYZ axes. A positioning mechanism is provided, and by the operation of a positioning control device provided separately, it is possible to specify an arbitrary pattern number and to position the discharge nozzle 1a of the dispenser 1 with respect to the joint specified by the pattern number. It has been done.

6 is a discharge adjusting mechanism for starting and stopping the discharge of the solder paste from the discharge nozzle 1a of the dispenser 1, and 8 is a weight reduction of the dispenser 1 due to the supply of the solder paste to the joint on the circuit board 4. An electronic balance 9 functioning as a minute weight detecting means capable of detecting the minute amount is a control device that controls the start and stop of the discharge of the solder paste by operating the discharge adjusting mechanism 6 based on a signal from the electronic balance 8.

The control device 9 is constituted by a microcomputer or the like, and its internal memory stores a table having the contents shown in FIG. 2 as described in the previous example. This table stores the expected supply weight of the solder paste for each pattern number. here,
“Each pattern number” is a number assigned to each joint on the circuit board 4. Since the expected supply weight of the solder paste usually differs depending on the size of the joint, the unique expected supply weight for each individual joint is stored in this table.

Next, the operation of the automatic solder paste supply device having the above configuration will be described. When the pattern number of the joint is specified, the discharge nozzle 1a of the dispenser 1 is positioned above the joint specified by the pattern number by the operation of a three-axis relative positioning mechanism (not shown).
Then, upon receiving a command from the control device 9, the discharge adjusting mechanism 6
Is activated, and supply of the solder paste from the discharge nozzle 1a of the dispenser 1 to the corresponding joint on the circuit board 4 is started.

When the supply of the solder paste is started, the total weight of the dispenser 1 is reduced by the amount of the supplied solder paste, though the amount is small. The weight of the dispenser 1 is measured by an electronic balance 8 constituting a minute weight detecting means, and the measured value is sent to a control device 9.

The controller 9 calculates the weight loss based on the weight of the dispenser at the start of the solder paste supply to the joint, and the weight reduction reaches the scheduled supply weight stored in the table shown in FIG. At this point, a predetermined command is given to the discharge adjusting mechanism 6. Then, the discharge adjusting mechanism 6 operates, and the supply of the solder paste from the discharge nozzle 1a of the dispenser 1 to the joint on the circuit board 4 is stopped.

As a result of the above operations being repeated for the joints of each pattern number, it becomes possible to supply an appropriate amount of solder paste to each joint accurately.

Next, a third embodiment of a method and an apparatus for automatically supplying a solder paste according to the present invention will be described with reference to FIGS.

In FIG. 4, reference numeral 1 denotes an injection type dispenser for discharging the solder paste 2 filled therein from a discharge nozzle 1a, 10 denotes a horizontal stage located below the dispenser 1, and 4 denotes a horizontal stage mounted on the horizontal stage 10. The circuit board 5 which is placed and has on its upper surface a plurality of joints specified by a pattern number to be described later is solder paste supplied to one of the joints on the circuit board 4.

Although not shown, even in this example, a three-axis relative position between the discharge nozzle 1a of the dispenser 1 and each joint of the circuit board 4 for positioning them along the XYZ axes. A positioning mechanism is provided, and by the operation of a positioning control device provided separately, it is possible to specify an arbitrary pattern number and to position the discharge nozzle 1a of the dispenser 1 with respect to the joint specified by the pattern number. It has been done.

6 is a discharge adjusting mechanism for starting and stopping the discharge of the solder paste from the discharge nozzle 1a of the dispenser 1, and 11 is an electrode rod 12 inserted vertically into the solder paste storing section of the dispenser 1 and an outer wall 13 of the storing section. This is a resistance meter that measures the resistance value between. The resistance meter 11 outputs a resistance measurement value corresponding to the volume of the solder paste stored in the dispenser 1. That is, the ohmmeter 11 that measures the electric resistance value between the electrode rod 12 and the outer wall 13 of the storage unit detects the volume decrease of the dispenser 1 due to the supply of the solder paste to the joint on the circuit board 4. It functions as a possible trace volume detection means.

A control device 14 controls the start and stop of the discharge of the solder paste by operating the discharge adjusting mechanism 6 based on a signal from the electronic balance 8. The control device 14 is constituted by a microcomputer or the like, and its internal memory stores a table having the contents shown in FIG. This table stores the expected supply volume of the solder paste for each pattern number. here,
“Each pattern number” is a number assigned to each joint on the circuit board 4. Since the scheduled supply volume of the solder paste usually differs depending on the size of the joint, the unique scheduled supply volume for each joint is stored in this table.

Next, the operation of the automatic solder paste supply device having the above-described configuration will be described. When the pattern number of the joint is specified, the discharge nozzle 1a of the dispenser 1 is positioned above the joint specified by the pattern number by the operation of a three-axis relative positioning mechanism (not shown).
Then, the discharge adjustment mechanism 6 is operated in response to a command from the control device 14, and the supply of the solder paste from the discharge nozzle 1 a of the dispenser 1 to the corresponding joint on the circuit board 4 is started.

When the supply of the solder paste is started, the volume of the solder paste in the dispenser 1 is reduced by the amount of the supplied solder paste, albeit a small amount. The volume of the solder paste in the dispenser 1 is measured by a resistance meter 11 constituting a minute volume detecting means, and the measured value is sent to a control device 14.

The controller 14 calculates the volume decrease based on the solder paste volume in the dispenser at the start of the solder paste supply to the joint, and the volume decrease is scheduled to be stored in the table shown in FIG. When the supply volume is reached, a predetermined command is given to the discharge adjustment mechanism 6. Then, the discharge adjusting mechanism 6 operates, and the supply of the solder paste from the discharge nozzle 1a of the dispenser 1 to the joint on the circuit board 4 is stopped.

As a result of the above operation being repeated for the joints of each pattern number, it becomes possible to supply an appropriate amount of solder paste to each joint accurately.

[0046]

As is apparent from the above description, according to the present invention, it is possible to minimize the amount of excess solder discarded at the time of manufacturing a component mounting board and to adjust the amount of solder supplied to each joint on the board. Therefore, the amount of lead eluted into the environment after product disposal can be reduced as much as possible.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a solder paste automatic supply device according to the present invention.

FIG. 2 is an explanatory diagram showing the contents of a table stored in a control device 7 of FIG.

FIG. 3 is a configuration diagram showing a second embodiment of the automatic solder paste supply device according to the present invention.

FIG. 4 is a configuration diagram showing a third embodiment of the automatic solder paste supply device according to the present invention.

5 is an explanatory diagram showing the contents of a table stored in a control device 14 of FIG.

FIG. 6 is an explanatory view showing an example of a conventional solder paste supply method.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Dispenser 2 Solder paste 3 Electronic balance (for measuring board weight) 4 Circuit board 5 Solder paste supplied on board 6 Discharge adjusting mechanism 7 Control device 8 Electronic balance (for measuring dispenser weight) 9 Control device 10 Horizontal stage 11 Resistance Total 12 Electrode rods 13 Reservoir outer wall 14 Control device

Claims (6)

[Claims] 1. An apparatus for supplying an appropriate amount of solder paste to a joint on a substrate by an injection type dispenser, wherein a supply weight of solder paste scheduled for each joint on the substrate is stored. Storage means, and a trace weight detecting means capable of detecting an increase in the weight of the board due to the supply of the solder paste to the joint portion on the board; and starting discharge of the solder paste from a solder paste discharge nozzle of the dispenser. Control means for stopping the discharge of the solder paste in response to the increment of the substrate weight detected by the trace weight detection means reaching the scheduled supply weight stored in the storage means. Automatic solder paste supply device. 2. An apparatus for supplying an appropriate amount of solder paste to joints on a substrate by an injection type dispenser, wherein a supply weight of the solder paste scheduled for each joint on the substrate is stored. Storage means, a minute weight detecting means capable of detecting weight loss of the dispenser due to the supply of the solder paste to the joint portion on the substrate, and starting discharge of the solder paste from a solder paste discharge nozzle of the dispenser. And control means for stopping discharge of the solder paste in response to the dispenser weight decrement detected by the trace weight detection means reaching the scheduled supply weight stored in the storage means. A solder paste automatic supply device characterized by the above-mentioned. 3. An apparatus for supplying an appropriate amount of solder paste to a joint on a substrate by an injection type dispenser, wherein a predetermined solder paste supply volume is stored for each joint on the substrate. Storage means, a small volume detection means capable of detecting a decrease in the volume of the solder paste in the dispenser due to the supply of the solder paste to the joint on the substrate, and discharge of the solder paste from a solder paste discharge nozzle of the dispenser. And control means for stopping the discharge of the solder paste in response to the solder paste volume decrement detected by the trace volume detection means reaching the scheduled supply volume stored in the storage means, An automatic solder paste supply device comprising: 4. A method for supplying an appropriate amount of solder paste to a joint on a substrate by an injection type dispenser, the method comprising: starting discharge of solder paste from a solder paste discharge port of the dispenser. Detecting a board weight increment caused by the supply of the solder paste onto the board by the discharging; and responding to the fact that the detected board weight increment reaches a solder paste supply weight expected at the joint. Stopping the discharge of the solder paste. A method for automatically supplying solder paste, comprising: 5. A method for supplying an appropriate amount of solder paste to a joint on a substrate by an injection type dispenser, the method comprising: starting discharge of solder paste from a solder paste discharge port of the dispenser; Detecting a weight loss of the dispenser due to the discharge of the solder paste, and discharging the solder paste in response to the detected weight loss of the dispenser reaching a solder paste supply weight expected at the joint. A method for automatically supplying a solder paste, comprising the steps of: 6. A method for supplying an appropriate amount of solder paste to a joint on a substrate by an injection type dispenser, the method comprising: starting discharge of solder paste from a solder paste discharge port of the dispenser; Detecting a solder paste volume decrease in the dispenser due to the discharging; and, in response to the detected solder paste volume decrease reaching a predetermined solder paste supply volume at the joining portion, the solder paste Stopping the discharge; and a method for automatically supplying a solder paste.