JPH11320822A - Solder printing device and solder printing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a favorable printing with solder by a method wherein an air discharging part, which makes the solder filled in the holes of a mask fall on a board with air pressure, is provided in the contacting part of a squeegee with the mask in the printing of the solder supplied onto the mask on the board by moving the squeegee on the mask. SOLUTION: When a solder 4 is printed on a board 2 in the mounting process of electronic parts, first of all, a make 1 is fixed under the condition that a small clearance is made between the board 2 and the mask 1. Next, a squeegee 6, to which an air feeding tube for feeding a compressed air is connected, is lowered so as to be moved towards one direction under the condition that some part of the mask 1 is brought into close contact with the board 2. Thus, the solder 4 is filled in the holes 1a of the mask 1 within the range of the mask contacting part 6a of the squeegee 6. Further, at this time, within the range B of the mask contacting part 6a, in which the mask 1 separates from the board 2, the solder 4 is forcibly made to be fallen from the holes 1a of the mask 1 on the board 2a by means of the air pressure of the compressed air discharged from an air discharging groove 6b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solder printing apparatus and method for printing solder on a board in an electronic component mounting process.

[0002]

2. Description of the Related Art Conventionally, two types of solder printing methods are used for printing solder on a board in an electronic component mounting process. In the solder printing method, as shown in FIG. 4, the squeegee 3 is moved in the direction a while the entire mask 1 is in close contact with the substrate 2, and the solder 4 on the mask 1 is moved.
Is printed on the substrate 2, and the other solder printing method is to print the solder 4 by bringing only a part of the mask 1 into close contact with the substrate 2 during printing, as shown in FIG. 5. . 1a is a hole in the mask 1.

The former solder printing process shown in FIG. 4 is described in detail below. The mask 1 is brought into close contact with the substrate 2. The squeegee 3 is moved to remove the solder 4 from the hole 1a of the mask 1.
Into

After the movement of the squeegee 3 is completed, the squeegee 3 and the mask 1 are raised, so that the solder 4 in the hole 1a of the mask 1 remains on the substrate 2 and printing is completed. The latter solder printing step shown in FIG. 5 will be described in detail below.

[0005] The mask 1 is fixed with a gap between the substrate 2 and the mask 1. The squeegee 3 is lowered to bring a part of the mask 1 into close contact with the substrate 2. The squeegee 3 is moved to remove the solder 4 from the hole 1a of the mask 1.
Into

At the point where the squeegee 3 has passed,
The mask 1 released from the pressing force of the squeegee 3 rises, and the solder 4 in the hole 1a of the mask 1 remains on the substrate 2. After the movement of the squeegee 3 ends, printing is completed.

[0007]

One of the factors that determine the printability of the solder 4 is the flux (liquid) contained in the solder 4.
There is an amount. When the flux is small, the viscosity increases, and the solder 4 easily adheres to the mask 1. Therefore, at the time of printing, a sufficient amount of solder 4
Does not fall, so-called blurring of the solder 4 occurs.

On the other hand, when the flux is large, since the viscosity of the solder 4 is low, a sufficient amount of the solder 4 can be dropped from the mask 1 onto the substrate 2. However, after printing, the shape of the solder 4 collapses, so-called bleeding of the solder 4 occurs. Therefore, when the land pitch is narrow, there occurs a problem that the adjacent solders 4 mix with each other.

Conventionally, in order to prevent the above-mentioned problems, a solder 4 containing an appropriate amount of flux is used.
It was necessary to keep the solder 4 at a constant viscosity while paying attention to the amount of the volatilizing flux.

As described above, in the conventional technique, since the solder 4 is printed under optimum conditions, the operator must always pay attention to the amount of the flux that changes with time, the viscosity of the solder 4, and the like. It took much time and reduced the work efficiency.

The present invention has been made to solve the above-mentioned problems, and it is possible to prevent the blurring and bleeding and to print the solder well even when the printing conditions slightly change due to the change of the amount of flux, the viscosity of the solder, and the like. It is an object of the present invention to provide a solder printing apparatus and a solder printing method that can be used.

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a solder printing apparatus of the present invention moves a squeegee in a predetermined direction on a mask and prints the solder supplied on the mask on a substrate. An apparatus is provided, wherein an air discharge section is formed at a mask contact portion of a squeegee so that air is supplied and solder filled in holes of the mask is forcibly dropped on a substrate by air pressure.

According to this configuration, even if the printing conditions slightly change due to a change in the amount of the flux, the viscosity of the solder, and the like, it is possible to prevent the blurring and bleeding and to print the solder well.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A solder printing apparatus according to a first aspect of the present invention is a solder printing apparatus for moving a squeegee in a predetermined direction on a mask and printing the solder supplied on the mask on a substrate. , At the mask contact part in the squeegee,
Air is supplied and the air filled in the hole of the mask is forced to fall on the substrate by air pressure to form an air discharge unit, which allows air to be discharged from the air discharge unit when the squeegee moves. Then, the solder filled in the holes of the mask is forcibly dropped onto the substrate by the air pressure from the air discharge portion and printed.

According to a second aspect of the present invention, there is provided a solder printing apparatus according to the first aspect, wherein the air discharging portion extends in a squeegee width direction orthogonal to a squeegee moving direction at a mask contact portion of the squeegee. The squeegee is constituted by an air discharge groove, and supplies air from an air supply pipe connected to the squeegee to the air discharge groove via a communication passage provided inside the squeegee. The air can be satisfactorily supplied to the groove, and the printing state can be improved.

According to a third aspect of the present invention, there is provided a solder printing method in which a squeegee is moved in a predetermined direction on a mask and the solder supplied on the mask is printed on a substrate. By discharging air from an air discharge portion provided at a mask contact portion of the squeegee, the solder filled in the hole of the mask with the squeegee is forcibly dropped onto the substrate by air pressure from the air discharge portion and printed. Because of this, it is forced to drop on the substrate with air pressure and printing, the amount of flux,
Even if the printing conditions slightly change due to a change in the viscosity of the solder or the like, it is possible to prevent the blurring and bleeding and to print the solder well.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIG. Note that components having similar functions are denoted by the same reference numerals and described. As shown in FIG. 1, a solder printing apparatus according to the present invention includes a mask 1 which can be moved up and down and can be arranged at an upper position with a small gap t with respect to a substrate 2 at a predetermined position. A squeegee 6 is provided which is movable on the mask 1 in a predetermined direction (a direction).

An air supply pipe 7 for supplying compressed air is connected to the squeegee 6, and an air discharge groove 6b for discharging compressed air from the air supply pipe 7 is formed in a mask contact portion 6a on the lower surface. Have been. This air discharge groove 6b
Is a mask contact portion 6a of the squeegee 6, as shown in FIG.
, The squeegee extends in the squeegee width direction orthogonal to the squeegee moving direction a. Further, inside the squeegee 6, a plurality of horizontal communication passages 6c extending in the horizontal direction (squeegee width direction) directly from the connection point with the air supply pipe 7, and a plurality of horizontal communication passages 6c are formed at appropriate intervals from the horizontal communication passages 6c and are formed downward. Extend the air discharge groove 6
b and a vertical communication passage 6d communicating with the air supply pipe 7b.
Is supplied to the air discharge groove 6b through the horizontal communication passage 6c and the vertical communication passage 6d.

As shown in an enlarged view in FIG. 3, a portion of the mask contact portion 6a of the squeegee 6 near the moving direction (portion A in FIG. 3) is formed with a horizontal contact surface. The pressed mask 1 comes into close contact with the substrate 2. On the other hand, the air discharge groove 6
The portion of the mask contact portion 6a provided with the b in the rearward direction in the movement direction (portion of the range B in FIG. 3) is formed to be inclined so that the rear side is slightly upward, and the mask 1 pressed by the squeegee 6 Are gradually separated from the substrate 2.

The solder is printed by the solder printing apparatus as follows. The mask 1 is fixed with a slight gap t from the substrate 2.
(See FIG. 1) The squeegee 6 is moved while the squeegee 6 is lowered and a part of the mask 1 is in close contact with the substrate 2.

As shown in FIG. 3, the moving squeegee 6
The solder 4 supplied onto the mask 1 is filled in the holes 1a of the mask 1 by the portion of the range A in the mask contact portion 6a.

In the area B of the mask contact portion 6a of the squeegee 6, the mask 1 is separated from the substrate 2 and the solder 4 is forcibly forced out of the hole 1a of the mask 1 by the air pressure of the compressed air discharged from the air discharge groove 6b. Dropped on the substrate 2.

In the area C where the squeegee 6 has passed, the mask 1 released from the pressing force of the squeegee 6 rises. As described above, when the solder 4 is printed using the solder printing apparatus and the solder printing method, the solder 4 in the mask 1 can be forcibly dropped by the air pressure of the compressed air discharged from the air discharge groove 6b. Therefore, the flux 4 is small, and even the solder 4 that does not easily fall from the mask 1 to the substrate 2 can be easily and reliably dropped.
Blurring of the solder 4 can be prevented. In addition, when the solder 4 having a small flux is used, the bleeding of the solder 4 can be prevented, and the solder 4 can be printed well, so that the print quality is improved. Further, the operator does not have to always pay attention to the amount of the flux that changes with time, the viscosity of the solder 4, and the like.

[0024]

As described above, according to the present invention, since the solder in the mask is forcibly dropped by the compressed air from the squeegee, the blurring or bleeding of the solder can be prevented, so that the print quality is improved. Further, since the operator does not need to always pay attention to the amount of the flux and the viscosity of the solder which change over time, the work efficiency is improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a solder printing apparatus according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view of a squeegee of the solder printing apparatus (FIG. 1);
Arrow sectional view from the direction of arrow D)

FIG. 3 is a partially enlarged view of the solder printing apparatus.

FIG. 4 is a cross-sectional view showing a conventional solder printing method for printing a mask in close contact with a substrate.

FIG. 5 is a cross-sectional view showing a conventional solder printing method for printing a mask away from a substrate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mask 1a Hole 2 Substrate 4 Solder 6 Squeegee 6a Mask contact part 6b Air discharge groove 6c Horizontal communication path 6d Vertical communication path 7 Air supply pipe

Claims (3)

[Claims] 1. A solder printing apparatus for printing a solder supplied on a mask on a substrate by moving a squeegee in a predetermined direction on a mask, wherein air is supplied to a mask contacting portion of the squeegee to form the mask. A solder printing apparatus having an air discharge unit for forcibly dropping the solder filled in the holes onto the substrate by air pressure. 2. The squeegee according to claim 2, wherein the air discharge portion is formed by an air discharge groove extending in a squeegee width direction orthogonal to a squeegee moving direction at a mask contact portion of the squeegee. 2. The solder printing apparatus according to claim 1, wherein the air is supplied to the air discharge groove via a communication path provided inside. 3. A solder printing method for moving a squeegee in a predetermined direction on a mask and printing solder supplied on the mask on a substrate, wherein air is provided at a mask contact portion of the squeegee when the squeegee is moved. A solder printing method in which the air filled in the mask hole is forcibly dropped by an air pressure from the air discharge unit onto the substrate by discharging air from the unit and printing is performed.