JP2002103563A - Cream solder printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cream solder printer capable of printing a cream solder by sufficiently operating a rolling force on the solder moving by a squeegee. SOLUTION: The squeegee 20 provided in the cream solder printer has a square bar-like protrusions 24I to 24K formed along a squeegee surface in a direction perpendicular to a width direction V at both ends in the width direction V. A cream solder 26E moved in the width direction V of the squeegee 20 by moving the squeegee 20 and arriving at the protrusion 24 is restricted in movement in the direction V by the protrusions 24. Thus, solder reservoirs are formed at both ends of the squeegee 20 in the width direction, and a rolling force is operated at the reservoirs toward a screen surface. Thus, when the solder 26E is filled in an opening 32 of the screen 28, a sufficient filling force is operated at the solder 26E. Accordingly, the solder 26E can be stably printed on a surface to be printed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cream solder printing apparatus capable of printing cream solder well.

[0002]

2. Description of the Related Art Screen printing for printing solder on a surface to be printed, such as a printed circuit board, is frequently used. In this screen printing, a cream solder printing apparatus for printing cream solder is generally used.

In a conventional cream solder printing apparatus, a flat squeegee 70 is held by a holder 72 as shown in FIG. 8, and a screen 78 serving as a mask as shown in FIGS. 9 and 10. The cream solder 76 (hereinafter simply referred to as solder 76) supplied on the squeegee 70
The solder 76 is printed on the lands 81 formed on the substrate 80 by moving while pressing. That is, the solder 76 moves in the moving direction U of the squeegee 70.
By moving while being pressed, the roller 82 moves while rolling, and is filled in the opening 82 formed in the screen 78 during the movement and printed on the land 81.

Since the squeegee 70 is flat in the width direction V, as shown in FIG.
Of the squeegee 70 as well as the moving direction U of the squeegee 70. The direction in which the solder spreading in the width direction V of the squeegee 70 moves in this manner differs depending on the position of the solder (U direction, B direction, and V direction in FIG. 9).
See directions). The solder 76E reaching the end of the squeegee 70 in the width direction V moves in the V direction and protrudes from the end of the squeegee.

That is, a force for preventing the movement in the width direction V does not act on the solder 76E reaching the end of the squeegee 70 in the width direction V. As a result, this solder 76E
The rolling force F in the moving direction U of the squeegee 70 (see FIG. 10)
Does not work much. If the rolling force F does not act, the solder 76E simply moves on the screen 78 without rotation.

Therefore, even if the solder 76E reaches the opening 82, the filling force does not sufficiently act on the solder 76E, and there is a problem that printing becomes unstable.

This problem has become particularly serious when electronic components are mounted on a printed circuit board at high density.

Japanese Patent Application Laid-Open No. 6-24167 discloses a cream solder printing apparatus using a metal mask to prevent the diffusion of solder in the width direction (see FIGS. 11 and 12). As shown in FIG. 11, this metal mask 88
This is a mask in which a plurality of ridges 90 toward the center of the mask are formed in parallel with each other, and a direction V ′ perpendicular to the ridges 90 (FIG.
2) is restricted.

[0009] However, there is a drawback that the ridges 90 cannot be easily formed by processing a metal mask requiring precision. Further, since the solder is formed toward the center of the metal mask 88, the solder passing through the center of the metal mask 88 spreads in the width direction of the squeegee 98.

[0010]

SUMMARY OF THE INVENTION In view of the above, the present invention provides a cream solder printing apparatus capable of printing cream solder satisfactorily by sufficiently applying a rolling force to cream solder moved by a squeegee. That is the task.

[0011]

According to the present invention, in a cream solder printing apparatus provided with a squeegee for screen-printing cream solder, the squeegee is provided with projections at both ends in the width direction of the squeegee. The movement of the cream solder in the width direction is restricted by the projections.

[0012] The solder which has moved to the convex portion by moving in the width direction of the squeegee is restricted from moving in the squeegee width direction by the convex portion. For this reason, a solder pool is formed at both ends in the width direction of the squeegee, and a new flow force, that is, a rolling force toward the screen acts on the solder pool.

Thus, when filling the opening of the screen with the cream solder reaching the end in the width direction of the squeegee, a sufficient filling force acts on the cream solder.
Therefore, the cream solder can be stably printed on the printing surface.

In the invention according to claim 2, the convex portion is
It is a bar-shaped protrusion provided along the squeegee surface in a direction perpendicular to the width direction of the squeegee.

Thus, the shape of the projection can be simplified. Note that the rod shape may be a square bar shape or a round bar shape, and the cross-sectional shape of the protruding portion is not particularly limited.

According to a third aspect of the present invention, a plurality of the protrusions are provided in parallel with each other.

[0017] Thus, the solder that has passed over the protruding portion is
The movement in the squeegee width direction is restricted by the adjacent protrusion. Therefore, the height of the protruding portion can be reduced as compared with the invention described in claim 2.

In the invention according to claim 4, the convex portion is
The squeegee is characterized in that the projections are arranged in a staggered manner along a direction orthogonal to the width direction of the squeegee.

Thus, the same effect as the effect according to the third aspect of the present invention can be obtained.

In the invention according to claim 5, the convex portion is
It is characterized in that it is provided at a position where no pressing force is applied to the screen when printing cream solder.

This prevents the projection from scratching the screen and hindering the squeegee angle adjustment.

According to a sixth aspect of the present invention, in the cream solder printing apparatus provided with a squeegee for screen-printing the cream solder, a concave portion is provided at a central portion of the squeegee for restricting movement of the cream solder in a width direction of the squeegee. Is formed.

Thus, by forming the concave portion by simple processing or molding, a convex portion for restricting the movement of the cream solder in the width direction of the squeegee is formed at both ends in the width direction of the squeegee.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A cream solder printing apparatus according to a first embodiment will be described. In the cream solder printing apparatus according to the first embodiment, as shown in FIG. 1, a squeegee 20 is held by a holder 22.

As shown in FIGS. 1 and 2, the squeegee 20
Are square bar-shaped protrusions 2 provided at both ends in the width direction V so as to protrude along the squeegee surface in a direction orthogonal to the width direction V.
4 A plurality of protrusions 24 are provided in parallel with each other at each end of the squeegee 20 in the width direction V, and the movement of the cream solder in the width direction V of the squeegee 20 is regulated by the protrusions 24.

As shown in FIGS. 3 and 4, in order to print cream solder 26 (hereinafter simply referred to as solder 26) on a printed circuit board 30 which is a printing surface, the solder 26 supplied on a screen 28 is printed. Printing is performed by moving the squeegee 20 while pressing in the U direction. That is, solder 2
The screen 6 moves while rolling by being pushed while moving in the movement direction U of the squeegee 20, and the screen 28 moves.
Is filled in the middle of the movement in the opening 32 formed on the printed circuit board 30, and is printed on the land 36 (see FIG. 4) formed on the printed circuit board 30.

At this time, as shown in FIG.
The squeegee 20 moves and spreads not only in the moving direction U but also in the width direction V of the squeegee 20.

The solder 26E reaching the end of the squeegee 20 in the width direction V is restricted from moving in the V direction by the protruding portion 24, even if the solder 26E attempts to move in the V direction. Therefore, a solder pool is formed at both ends in the width direction of the squeegee 20, and a new flow force is applied to the solder pool, that is, a rolling force F such that the solder 26E is stirred toward the screen 28 as shown in FIG. (See FIG. 3).

Therefore, when filling the opening 32 with the solder 26E reaching the end of the squeegee 20 in the width direction V, a sufficient filling force acts on the solder 26E. Thus, the solder 26E can be stably printed on the land 36.

A plurality of protrusions 24 are provided in parallel with each other (see FIGS. 1 to 3). Therefore, as shown in FIG. 3, the solder that has passed over the innermost protruding portion 24I is
Projection 24J provided just outside projection 24I
Accordingly, the movement in the V direction is restricted, and the solder that has also passed over the protrusion 24J is prevented from moving in the V direction by the protrusion 24K provided immediately outside the protrusion 24J.

This makes it possible to reduce the height (projection length) of the projection 24 as compared with the case where only one projection 24 is provided.

As shown in FIG. 4, in this embodiment,
The squeegee 20 moves at an inclination angle of θ = about 60 ° with respect to the screen 28. Based on this, the protrusion 24
Of the protruding portion 24 so that the lower end 24L of the protruding portion 24 lightly contacts the screen 28, or a small gap d is formed between the lower end 24L of the protruding portion 24 and the screen 28 so that the solder 26 is printed. The pod arrangement position is determined.

Thus, when the solder 26 is screen-printed, the projection 28 prevents the screen 28 from being scratched and prevents the angle adjustment of the squeegee 20 from being hindered.

In this embodiment, the protruding portion 24 has a square rod shape. However, as shown in FIG. 5, the squeegee 20 is provided with a protruding portion 37 having a cylindrical surface on the moving direction side (U direction side) of the squeegee 20. It may be provided. Even in this case, the solder 26
A rolling force such that E is stirred toward the screen 28 acts, and the solder 26E can be stably printed on the land.

Next, a cream solder printing apparatus according to a second embodiment will be described. As shown in FIG. 6, the cream solder printing apparatus according to the second embodiment has a squeegee 40
However, at both ends in the width direction V, the prismatic projections 44 arranged in a staggered manner along the direction orthogonal to the width direction V are replaced with square rod-shaped projections 24 (see FIGS. 1 to 3). Have.

Thus, the movement of the solder reaching the protrusion 44 in the width direction V of the squeegee 40 is restricted, so that a solder pool is formed and an opening formed in the screen is formed, as in the first embodiment. When the portion is filled with solder, a sufficient filling force acts on the solder.

It should be noted that the same effect can be obtained even if the projection 44 is cylindrical or triangular pyramid-shaped.

Next, a cream solder printing apparatus according to a third embodiment will be described. As shown in FIG. 7, the squeegee 50 of the cream solder printing apparatus according to the third embodiment has a concave portion 52 formed at the center in the width direction V. As a result, the squeegee 5
Steps are formed at both ends in the width direction of 0 to form the convex portions 54.

The side wall surface 54S inside the convex portion 54 is
The squeegee 50 has a surface substantially perpendicular to the width direction V.

According to the third embodiment, the solder reaching the convex portion 54 is also restricted from moving in the V direction, whereby a solder pool is formed and formed on the screen as in the first embodiment and the second embodiment. When filling the formed opening with solder, a sufficient filling force acts on the solder.

[0041]

According to the present invention having the above-described configuration, the following effects can be obtained.

According to the first aspect of the present invention, when filling the opening of the screen with the cream solder reaching the end in the width direction of the squeegee, a sufficient filling force acts on the cream solder. . Therefore, the cream solder can be stably printed on the printing surface.

According to the second aspect of the invention, the shape of the projection can be simplified.

According to the third aspect of the present invention, the movement of the solder having passed over the projecting portion in the squeegee width direction is restricted by the adjacent projecting portion. Therefore, the height of the protruding portion can be reduced as compared with the invention described in claim 2.

According to the invention set forth in claim 4, according to claim 3,
The same effect as the effect according to the invention described in (1) can be obtained.

According to the fifth aspect of the present invention, it is possible to prevent the projection from scratching the screen and hinder the angle adjustment of the squeegee.

According to the sixth aspect of the present invention, the concave portion is formed by simple processing or molding, so that the convex portion for restricting the movement of the cream solder in the width direction of the squeegee is provided at both ends in the width direction of the squeegee. Is formed.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a squeegee of a cream solder printing apparatus according to a first embodiment.

FIGS. 2A and 2B are a plan view and a side view showing a squeegee of the cream solder printing apparatus according to the first embodiment, respectively.

FIG. 3 is a conceptual plan view showing that cream solder moves on a screen by a squeegee in the first embodiment.

FIG. 4 is a side cross-sectional view taken along line 4-4 of FIG. 3, showing that cream solder moves on a screen by a squeegee in the first embodiment.

FIG. 5 is a conceptual plan view showing that cream solder moves on a screen by a squeegee in a modification of the first embodiment.

FIGS. 6A and 6B are a plan view and a side view showing a squeegee of the cream solder printing apparatus according to the second embodiment, respectively.

FIG. 7 is a perspective view showing a squeegee of a cream solder printing apparatus according to a third embodiment.

8A and 8B are a perspective view and a side view showing a squeegee of a conventional cream solder printing apparatus, respectively.

FIG. 9 is a conceptual plan view showing that cream solder moves on a screen by a squeegee in a conventional cream solder printing apparatus.

FIG. 10 is a side sectional view taken along the arrow line 10-10 in FIG. 9, showing that the cream solder moves on the screen by the squeegee in the conventional cream solder printing apparatus.

FIG. 11 is a plan view of a metal mask disclosed in Japanese Patent Application Laid-Open No. 6-24167.

FIG. 12 is a sectional view taken along line 12-12 of FIG. 11;

[Explanation of symbols]

 Reference Signs List 20 squeegee 24 projecting portion 24I projecting portion 24J projecting portion 24K projecting portion 28 screen 37 projecting portion 40 squeegee 44 projecting portion 50 squeegee 54 projecting portion 70 squeegee 78 screen 88 metal mask (screen) 98 squeegee

Claims (6)

[Claims] 1. A cream solder printing apparatus provided with a squeegee for screen-printing cream solder, wherein the squeegee has protrusions at both ends in the width direction, and the movement of the cream solder in the width direction of the squeegee causes the protrusion to move. A cream solder printing apparatus characterized by being regulated by: 2. The cream solder printing apparatus according to claim 1, wherein the projection is a bar-shaped projection provided along a squeegee surface in a direction orthogonal to a width direction of the squeegee. 3. The cream solder printing apparatus according to claim 2, wherein a plurality of the protrusions are provided in parallel with each other. 4. The cream solder printing apparatus according to claim 1, wherein the protrusions are protrusions arranged in a staggered manner along a direction orthogonal to a width direction of the squeegee. 5. The method according to claim 1, wherein the projection is provided at a position where no pressing force is applied to the screen when printing the cream solder. Cream solder printing equipment. 6. A cream solder printing apparatus provided with a squeegee for screen-printing cream solder, wherein a concave portion is formed at a central portion of the squeegee to regulate movement of the cream solder in a width direction of the squeegee. Cream solder printing equipment.