JPH0831685B2 - Pasty adhesive application device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention is suitable for applying a paste-like bonding agent such as cream solder or adhesive to a printed circuit board or the like. Regarding the device.

[Prior Art] Conventionally, a printed circuit board (hereinafter, abbreviated as PCB)
As a method of soldering chip parts to, a predetermined amount of cream solder is attached to the soldering position of the PCB and the chip parts are mounted at the soldering position, and then the PCB is heated in an electric furnace to melt the cream solder. There is known a reflow soldering method in which a chip component is firmly fixed.

As a method of applying cream solder to a PCB in such reflow soldering, conventionally, a dispenser method (for example, a special method in which cream solder filled in an airtight container is discharged from a nozzle to apply grease solder at a predetermined position) (See Japanese Laid-Open Patent Publication No. 59-130561) and a printing method for selectively printing solder on a PCB by attaching the solder with a metal mask formed in a pattern in close contact with the PCB. For example, JP-A-63
-119977 gazette), but especially when it is necessary to increase the supply amount of cream solder and to apply it thickly, or when unevenness with chip parts already mounted is applied to the PCB. When it was necessary to apply solder, a dispenser method was used exclusively.

Then, when performing solder coating on the PCB by the above-mentioned dispenser method, especially when it is necessary to apply solder to a plurality of places, in order to shorten the coating time, prepare a plurality of dispensers to perform coating at the same time, or Or first
As shown in FIG. 12, a multi-nozzle type dispenser having a large number of nozzles 2 at the tip of a syringe 1 is prepared, and cream solder filled in the syringe 1 is discharged from each nozzle 2 at the same time to perform coating. It was.

[Problems to be Solved by the Invention] However, in the method of performing multi-point coating using a large number of dispensers as described above, when the number of coating points is several tens, it is a trade-off with equipment cost. It is impossible to prepare such a number of dispensers, etc.
Eventually, the cream solder was sequentially applied by the required amount by the required amount, and the application time was unavoidably prolonged.

When a multi-nozzle type dispenser is used, the cream solder filled in the syringe 1 is distributed according to the diameter of each nozzle 2 and supplied to the PCB at the same time. Since the ejection resistance of each nozzle 2 varies due to occurrence, the amount of solder ejected from each nozzle 2 is not stable, and there is a drawback that the variation in the amount applied is large. Also, the number of nozzles 2 is practically limited to about 10 in view of the amount of cream solder that can be discharged at one time and the discharge pressure, and it is impossible to cope with more coating points.

In order to solve these drawbacks, an attempt was made to increase the amount of cream solder applied by increasing the thickness of the metal mask in the printing method using a metal mask,
The amount of cream solder applied did not increase as expected, and the method using a metal mask still could not apply the cream solder to the PCB after mounting the chip parts, so it was not practical.

This invention was made under such a background,
When applying a paste-like bonding agent such as cream solder or adhesive to multiple bonding agent application positions on a circuit board such as a PCB, the required amount of paste-like bonding agent can be applied reliably at multiple points in a short time. The purpose is to provide a device.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a paste-like bonding agent for fixing a circuit board such as a PCB and components mounted on the circuit board to a plurality of the circuit boards. A pasting agent applying device for applying to a bonding agent applying position, wherein a plurality of through holes are formed through one surface facing the circuit board and the other surface; A plurality of supply pipes, which are inserted into and fixed to the through holes of the coating substrate, and whose tips extend toward the bonding agent coating positions of the circuit board, and rollers provided on the other surface of the coating substrate so as to be rotatable. A paste-like bonding agent coating device was constructed from the above.

[Operation] In order to apply the paste-like bonding agent using the coating device having the above-described configuration, first the paste-like bonding agent is placed on the other surface of the coating substrate, and then the roller is moved along the other surface of the coating substrate. To roll.
Then, the paste-like bonding agent is sequentially pushed into each supply tube as the roller rolls, and is sequentially applied from the tip of the supply tube to each bonding agent application position on the circuit board.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

As shown in FIG. 1 (a), the coating apparatus of the present embodiment has a flat plate-like shape which is arranged so as to face a printed circuit board (hereinafter abbreviated as PCB) 3 on which chip components 3a to 3c are already mounted. Coating substrate 4, a plurality of supply pipes 5 provided so as to project from the lower surface (one surface) 4a side of coating substrate 4, and a roller arranged on the upper surface (other surface) 4b side of coating substrate 4. 6 and 6 are roughly configured.

In detail, the coating substrate 4 is defined to be slightly larger than the PCB 3 as shown in FIG. 2 and is provided so as to come in contact with and separate from the PCB 3 and has its upper surface 4b as shown in FIG. Is covered with a nickel plating layer 7 to prevent adhesion of cream solder. Further, as shown in FIGS. 1 (a) and 2, when the coating substrate 4 is disposed facing the PCB 3, each solder coating position of the PCB 3 (bonding agent coating position)
A plurality of through holes 8 penetrating the lower surface 4a and the upper surface 4b of the coating substrate 4 are formed at positions facing P1.

On the other hand, each of the supply pipes 5 is a circular pipe made of stainless steel, and the base end of each supply pipe 5 is fitted and fixed in each through hole 8 of the coating substrate 4 as shown in detail in FIG. The mouth of each base end is chamfered integrally with the nickel plating layer 7. Further, the tip of each supply pipe 5 extends straight downward from the lower surface 4a of the coating substrate 4 so that the coating substrate 4
When disposed so as to face the PCB3, each mouth is located near each bonding agent position P1. And
At the mouth of the tip of each supply pipe 5, there is formed a throttle port 9 that reduces the diameter of the tip opening of the supply pipe 5.

Further, as shown in FIGS. 1 (a) and 2, the roller 6 is formed by inserting a steel rod 6b into the center of a cylindrical urethane roll 6a formed to have substantially the same width as the coating substrate 4. ,
The front end of the steel rod 6b is rotatably supported by a moving mechanism (not shown) and is movable in the longitudinal direction of the coating substrate 4. As shown in FIG. 2, a pinion gear 10 is fitted to the other end of the steel rod 6b, meshes with a rack 11 arranged along the longitudinal direction of the coating substrate 4, and the urethane roll 6a. Is rotated around the steel rod 6b as it moves.

In order to apply the cream solder to each solder application position P1 of the PCB3 using the application device configured as described below, first, as shown in FIG. 1 (a), the roller 6 is attached to one end of the application substrate 4 (in the figure, The coating substrate 4 is arranged at a position facing the PCB 3 while being positioned at the right end). Then, the upper surface 4b of the coating substrate 4
Then, a sufficient amount of cream solder 12 is applied to all the solder application positions P1 on the PCB 3, and then the roller 6 is moved from one end to the other end of the application substrate 4 as shown in FIG. 1 (b). Move at a constant speed until. Then, urethane roll
6a moves to the left on the upper surface 4b of the coating substrate 4 while rotating counterclockwise around the axis due to the meshing of the pinion gear 10 and the rack 11, and as a result, as shown in FIG. Sequential supply pipe 5 with rotation
Of the urethane roll 6a is discharged from the throttle port 9 of the supply pipe 5 and supplied to the bonding agent application position P1 of the PCB3. Therefore, the cream solder 12 is applied to all the bonding agent application positions P1 on the PCB 3 by the time the roller 6 reaches the other end of the application substrate 4, and then the PCB 3 is removed from the application substrate 4 as shown in FIG. 1 (c). Then, the application of the cream solder 12 is completed and the PCB 3 is sent to the subsequent process.

Thus, in the coating apparatus of this embodiment, the roller 6
Since the cream solder 12 is applied to each solder application position P1 on the PCB 3 by one movement, the application time is significantly shortened as compared with the conventional dispenser method. By the way, an experiment was conducted to compare the coating time when the coating device of this example was used with that of the conventional dispenser system,
The solder coating positions of 70 points on the PCB were able to be coated in only 4 seconds in the coating apparatus of this embodiment, whereas it took 70 seconds to complete all coating in the case of using the dispenser.

Further, in the coating apparatus of the present embodiment, since the discharge pressure is applied to each supply pipe 5 independently from the peripheral surface of the urethane roll 6a, the solder discharge amount of each supply pipe 5 is the same as that of the other supply pipes 5. It is stable without being affected, and the amount of cream solder 12 corresponding to each caliber is reliably applied to each solder application position P1.

Here, in the above description, it was explained that the application amount of the cream solder 12 is basically determined by the diameter of the supply pipe 5, but in the application device of the present embodiment, there are other conditions that influence the application amount. It exists, and will be explained in order below.

First, even if the diameter of the supply pipe 5 is the same, if the base end side is chamfered as shown in FIG. Cream solder that is pushed inside compared to things
The amount of 12 increases and the coating amount increases.

Further, the coating amount is the peripheral surface of the urethane roll 6a and the coating substrate 4
It also depends on the amount of relative slip between the upper surface 4b and the upper surface 4b.
That is, as shown in FIG. 2, the rotation of the urethane roll 6a is caused by the meshing between the pinion gear 10 and the rack 11 accompanying the movement thereof, so that the pitch circle diameter d _{1 of} the pinion gear 10 and the urethane roll 6a When the diameter d _{2 of} 6a is different, the peripheral speed of the urethane roll 6a does not match the moving speed of the urethane roll 6a, and slippage occurs between the peripheral surface of the urethane roll 6a and the upper surface 4b of the coating substrate 4. Will be done. Then, as shown in FIG. _2, when the diameter d ₂ of the urethane roll 6a is smaller than the pitch circle diameter d ₁ of the pinion gear 10, the urethane roll 6a slides in its rotation direction (arrow Y1 direction in FIG. 3). It moves on the coating substrate 4, whereby more cream solder 12 is pushed into the supply pipe 5 to increase the coating amount. On the contrary, pinion gear
When the diameter of the urethane roll 6a is smaller than the pitch circle diameter d _{1 of} 10, the urethane roll 6a moves the coating substrate 4 while slipping in the direction opposite to the rotation direction thereof, whereby the supply pipe 5
The filling of the cream solder 12 inside is hindered and the application amount is reduced.

In addition to the above conditions, the surface pressure between the peripheral surface of the urethane roll 6a and the upper surface 4b of the coating substrate 4 and the urethane roll 6a
Of the coating substrate 4, the surface roughness of the upper surface 4b of the coating substrate 4, and the viscosity of the cream solder 12 also depend on the ambient temperature, so that the coating amount depends on the above conditions. By grasping the quantitative relationship between the application amount and the application amount, the amount of the cream solder 12 applied to each solder application position P1 of the PCB 3 can be more accurately matched with the desired application amount.

Next, some modifications of the above embodiment will be sequentially described with reference to FIGS. 4 to 9.

4 (a) to 4 (j) show various modifications of the supply pipe. The modified example shown in FIG. 4 (a) is one in which the simple hollow cylindrical supply pipe 5 is simply fixed to the through hole 8 and has an advantage that it can be easily manufactured by cutting a commercially available pipe material. On the other hand, in the modification shown in FIG. 4 (b), the base end of the supply pipe 5 is chamfered,
With such a shape, it is possible to increase the solder coating amount as described in the above-mentioned embodiment. A modified example shown in FIG. 4 (c) has the same effect as this. In this modified example, the base end mouth portion of the supply pipe 5 is expanded by performing a counterbore processing on the mouth of the through hole 8. The amount of cream solder to be pushed into the supply pipe 5 is increased. Further modified examples of these modified examples are modified examples shown in FIGS. 4 (d) to 4 (e), and these modified examples are also found in the above-described embodiment (see FIG. 3). As described above, the end of the supply pipe 5 has a throttle opening 9 for reducing the opening diameter.
Is formed, and the effect of improving the separation of the cream solder from the tip of the supply pipe 5 can be obtained by providing such a throttle opening 9.

Further, in the modification shown in FIG. 4 (f), when the shape of the solder coating position of the PCB is formed in an elliptical shape, the cross section of the supply pipe 5 is formed in an elliptical shape in accordance with this. As described above, in the coating apparatus of the present invention, by changing the cross-sectional shape of the supply pipe 5 in accordance with the shape of the solder coating portion, it is possible to easily deal with irregular-shaped coating.

Further, in the modified examples shown in FIG. 4 (g) and FIG. 4 (h), the supply pipe 5 is formed by notching the tip of the supply pipe 5 obliquely with respect to the PCB 3 or by edging it into a rectangular shape.
The mouth of the is opened to the side, and in these supply pipes 5, the open side of the tip faces the joint between the component temporarily fixed on the PCB and the PCB. By discharging, solder can be placed around the joint. Further, these modified examples are not limited to the simple hollow cylindrical supply pipe 5, but as shown in FIG. 4 (i), the supply pipe 5 already explained.
It is of course possible to chamfer the base end side of the above and also to implement it together with the one in which the squeeze port 9 is provided at the front end (see FIG. 4 (d)).

The modification shown in FIG. 4 (j) is particularly suitable for applying cream solder after mounting the leaded component on the PCB. This modification expands the tip of the supply pipe 5. By doing so, the lead 13 with the lead wire protruding from the PCB 3 is inserted into the inside of the supply pipe 5, and the cream solder is discharged in this state so that the supply pipe 5 can approach the PCB 3 without being disturbed by the lead 13. Lead 13
You can apply cream solder around the.

As described above, in the coating device having the above-described configuration, it is possible to easily cope with various coating modes by changing the shape of the supply pipe 5.

Next, various modifications relating to the movement of the rollers will be described with reference to FIGS.

Modifications shown in FIGS. 5 (a) to 5 (d) are ones in which a single roller 6 is reciprocally moved to perform coating.
In this modification, the roller 6 is provided so as to be movable up and down with respect to the upper surface 4b of the coating substrate 4. In the coating device provided with such a roller 6, first, the cream solder 12 is placed on the upper surface 4b of the coating substrate 4 as shown in FIG. 5 (a), and then shown in FIG. 5 (b). In this way, the roller 6 is moved from the right end to the left end of the upper surface 4b of the application substrate 4 to apply the cream solder 12 to the PCB. When the coating is completed in this way, the roller 6 is mounted on the coating substrate 4 as shown in FIG. 5 (c).
Of the remaining cream solder 12 as it rises from the top surface 4b of
Is moved in the horizontal direction so as to straddle the base plate, and then lowered again to the upper surface of the coating substrate 4 and moved to the opposite side of the cream solder 12. Then, after that, the PCB coated with the cream solder 12 is replaced with a new PCB, and the roller 6 is moved toward the right end of the coating substrate 4 as shown in FIG. 12 is applied. As described above, in the coating apparatus of this modification, the roller 6 reciprocates the coating substrate 4 to repeat the coating, so that the solder coating efficiency can be improved.

Further, in the modified example shown in FIGS. 6 (a) to 6 (d), two rollers 14 and 15 are arranged side by side along the longitudinal direction of the coating substrate 4, and each of these rollers 14 and 15 is arranged. Is rotatable about its own axis in the same manner as in the above-mentioned embodiment, and the coated substrate 4
Is provided so as to be movable along the longitudinal direction thereof and is also provided so as to be movable up and down with respect to the upper surface 4b of the coating substrate 4. In the coating apparatus including the rollers 14 and 15 having such a structure, first, the right roller 14 is brought into close contact with the upper surface 4b of the coating substrate 4 as shown in FIG. The rollers 14 and 15 are moved toward the left end of the coating substrate 4 in a state of being separated from each other to apply the cream solder 12. Next, as shown in FIG. 6 (b), the right side roller 14 is separated from the coating substrate 4 and the left side roller 15 is brought into close contact, and thereafter, the respective rollers 14, 15 are attached as shown in FIG. 6 (c). Application is performed by moving the coating substrate 4 toward the right end, and again, as shown in FIG. 6 (d), the rollers 14 and 15 are respectively brought into close contact with and separated from the coating substrate 4, and the same procedure is repeated. To continue applying cream solder 12. As described above, in this modified example, the horizontal operation of the rollers 14 and 15 is not necessary when switching the reciprocating operation as compared with the case of the single roller 6,
Further, since the ascending / descending operations of the rollers 14 and 15 are similarly performed, the switching time can be shortened and the efficiency can be further improved.

7 (a) to 7 (d), the flat roller scraper 16 having the same width as the roller 6 is provided in parallel with the single roller 6 described above. The scraper 16 is movable along with the roller 6 along the longitudinal direction of the coating substrate 4 and is movable up and down with respect to the upper surface 4b of the coating substrate 4. And such a scraper 16
In the coating apparatus having the above, as shown in FIG. 7 (a), the roller 6 is brought into close contact with the upper surface 4b of the coating substrate 4 and the scraper 16 is made to stand by above the upper surface 4b. As shown in (b), the roller 6 is moved from the right end to the left end of the application substrate 4 to apply the cream solder 12. Then, as shown in FIG. 7 (c), the roller 6 is raised and the scraper 16 is lowered to the vicinity of the coating substrate 4, and then the scraper 16 is moved toward the right end of the coating substrate 4 to remove the cream solder 12. Is evenly spread on the upper surface 4b of the coating substrate 4. Then, as shown in FIG. 7D, the roller 6 is lowered again and the scraper 16 is raised, and the application of the cream solder 12 is continued by repeating the same procedure. As described above, in this modification, the scraper is used when the solder coating is applied once and then the solder coating is changed to the next solder coating.
16 spreads the cream solder 12 gathered at the end of the coating substrate 4 by the roller 6 evenly over the entire upper surface 4b,
Even when the solder coating is repeatedly performed, a partial shortage of the cream solder 12 around each supply pipe 5 of the coating substrate 4 does not occur, and the variation in the amount of the cream solder 12 coated on the PCB is prevented for a long time. .

In the modification shown in FIG. 8 (a), a solder resin guide member 17 made of fluororesin is provided at both ends of the roller 6 so as to project in the traveling direction of the roller 6. In the coating device provided with such a solder guide member 17, even if the cream solder 12 spreads toward both ends of the roller 6 as the roller 6 moves, the cream solder 12 is blocked by the guide member 17 and is removed from both ends of the roller 6. Cream solder 12 to prevent escape
Wasteful consumption of The solder guide member 17 is not limited to the coating device having a single roller 6 and can be applied to a coating device having a plurality of rollers. For example, as shown in FIG. 8 (b), a coating device in which two rollers 14 and 15 are arranged side by side (6th
In the case of (see the drawing), the solder guide member 17 may be formed in a T-shape and arranged so as to close the gap between the rollers 14 and 15.

In addition, in the embodiment and each modification described above, the relation between the coating process used by the coating device and the component mounting process to the PCB is not clarified, but if a general example is shown,
As shown in Fig. (A), first, the cream solder 12 is applied to the solder application position P1 of the PCB3, and then the leaded parts such as the coil 18 are attached to the PCB3 as shown in Fig. 9 (b) and the electric furnace is installed. Can be heated. Also, as shown in FIG. 10 (a), a PC on which leaded components such as the coil 18 have already been mounted.
When attaching the frame foot 19 to B3, paste the cream solder 12 around the joint part of the frame foot 19 by using the supply pipe 5 (see FIG. 4 (g)) whose tip is notched, and then electrically connect the PCB3. The frame foot 19 can be fixed by heating in a furnace as shown in FIG. 10 (b), and further, the component 20 such that the lead 20a sticks out from the PCB 3 as shown in FIG. 11 (a). Even in the case of temporary fixing to, the cream solder 12 is applied with the lead 20a inserted into the inside of the supply pipe 5 by using the supply pipe 5 (see FIG. 4 (j)) whose tip is expanded. Afterwards, PCB3 can be heated in an electric furnace.

Further, in the above-mentioned embodiments and modified examples, the case where the cream solder is applied to the PCB is particularly described, but the application device of the present invention is not limited to this, and the chip component is applied to the PCB.
It is applicable to the application of all kinds of pasty adhesives such as adhesives for temporary fixing.

[Effects of the Invention] As described above, in the coating apparatus of the present invention, the pasty adhesive agent is applied from the tip of each supply pipe to each adhesive agent application position on the circuit board by one rolling of the roller. Therefore, even when the application position of the bonding agent reaches several tens, the application can be completed in an extremely short time. Then, since the discharge pressure is applied to each supply pipe independently from the peripheral surface of the roller, the discharge amount of the pasty bonding agent from each supply pipe is stable without being affected by other supply pipes, and the required amount of The pasty bonding agent is reliably applied to each bonding agent application position on the circuit board.

[Brief description of drawings]

FIGS. 1 to 3 are views showing an embodiment of the present invention, FIGS. 1 (a) to 1 (c) are views showing the constitution and the application procedure thereof, and FIG. 2 is a plan view thereof. FIG. 3 is an enlarged view of the vicinity of the supply pipe, FIGS. 4 to 8 are views showing a modification of the embodiment of the present invention, and FIGS. 4 (a) to 4 (j) are FIGS. 5 (a) to 5 (d) are views showing a coating procedure in the case of a single roller, and FIGS. 6 (a) to 6 (d) are views showing a modified example of the supply pipe shape. FIG. 7 (a) to FIG. 7 (d) are diagrams showing the coating procedure in the case of a plurality of rollers, and FIGS. 8 (a) to 8 (b) are diagrams showing the coating procedure when the scrapers are arranged in parallel. ) Figures showing a modified example in which solder guide members are provided at both ends of the roller, Figs.
FIG. 11 is a view showing the sequence of solder application and component mounting on the PCB using one embodiment of the present invention, and is shown in FIGS.
Figure (b) is a diagram showing the procedure for mounting leaded parts after solder coating, and Figures 10 (a) and 10 (b) are
Fig. 11 (a) to Fig. 11 (b) are the steps for attaching the frame feet to the PCB, and Fig. 11 (b) are the steps for attaching the leaded parts to the PCB first and then soldering them. FIG. 12 is a diagram showing a configuration of a conventional multi-nozzle type dispenser. 3 ... Printed circuit board, 4 ... Coating board, 4a ... Bottom surface (one surface), 4b ... Top surface (other surface), 5 ... Supply pipe, 6, 14, 15 ... Roller, 8 ... … Through hole, 12 …… Cream solder (paste bonding agent), P1… Solder application position (bonding agent application position).

Claims (1)

[Claims] 1. A paste-like bonding agent application device for applying a paste-like bonding agent for fixing a circuit board and components mounted on the circuit board to a plurality of bonding agent application positions on the circuit board, A coating substrate having a plurality of through holes penetrating one surface facing the circuit board and the other surface, a base end is inserted into each of the through holes of the coating substrate and fixed, and a tip end of the circuit board. A plurality of supply pipes extending toward each bonding agent application position,
A paste-like bonding agent coating apparatus comprising: a roller provided on the other surface of the coating substrate so as to be rotatable.