JP7369908B2 - Squeegee and printing device - Google Patents

Description

The present invention relates to a squeegee used in a printing device that prints paste on a substrate through a mask, and a printing device using this squeegee.

The printing device prints on the substrate by filling the openings provided in the mask with the solder paste supplied onto the mask using a squeegee that slides on the mask. The squeegee includes a plate-shaped blade that contacts the mask to fill the openings of the mask with solder paste, and a holding portion that holds the blade at an angle with respect to the mask. During printing, the solder paste can be appropriately printed on the substrate by sliding the blade on the mask while applying a suitable pushing pressure in the direction of the mask.

Urethane and metal are known as materials for such blades. Urethane blades are flexible, so by increasing or decreasing the amount that the blade is pushed into the mask, it is possible to change the amount of bend at the bottom end of the blade and change the angle of attack of the blade relative to the mask. Yes, it is easy to adjust the pushing pressure. On the other hand, urethane blades have the disadvantage of having a short lifespan in which they can be used repeatedly. Although metal blades have a long lifespan, they lack flexibility, resulting in small changes in bending, making it difficult to reduce the angle of attack and increase filling force. Therefore, in Patent Document 1, in order to compensate for the drawbacks of the metal blade, a thin band-shaped recess is formed in a part of the lower end of the metal blade, and the recess is curved by pushing pressure, so that the lower end of the blade is It has been proposed to tilt it at an angle suitable for printing.

Japanese Patent Application Publication No. 2009-45839

However, in Patent Document 1, since the life of the blade is limited by the thickness of the recess, there is a problem that if the thickness of the recess is made thinner in order to increase the curvature of the recess, the life will be shortened.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a squeegee and a printing device that can be used repeatedly, have a long life, and can appropriately print solder paste on a board.

The squeegee of the present invention is a squeegee that prints paste on a substrate by sliding on a mask provided with a predetermined opening, and the squeegee includes a metal blade that fills the opening with the paste, and a metal blade that fills the opening with the paste. a holding part held at an angle with respect to the mask, a part of the blade is provided with a linear softened part along the width direction of the blade , and the blade is brought into contact with the mask. Then, when the blade is further pushed down, the blade bends using the softened part as a fulcrum, and the angle of inclination that the part of the blade below the softened part makes with the mask is the same as the inclination of the blade held by the holding part. smaller than the corner .

A printing apparatus of the present invention includes the squeegee according to claim 1 or 2, and prints a paste on the substrate.

According to the present invention, the solder paste can be appropriately printed on a board with a long life that can be used repeatedly.

Structure explanatory diagram of a printing device according to an embodiment of the present invention A front view showing the structure of a printing device according to an embodiment of the present invention (a) (b) Structure explanatory diagram of a squeegee according to an embodiment of the present invention A front view showing the structure of a squeegee according to an embodiment of the present invention (a) (b) (c) An explanatory diagram of a printing process by a printing apparatus according to an embodiment of the present invention (a) (b) Diagrams explaining the structure and function of the second squeegee according to an embodiment of the present invention (a) (b) Diagrams explaining the structure and function of the third squeegee according to an embodiment of the present invention

An embodiment of the present invention will be described in detail below with reference to the drawings. The configuration, shape, etc. described below are examples for explanation, and can be changed as appropriate depending on the specifications of the printing device. Hereinafter, corresponding elements in all drawings will be denoted by the same reference numerals, and redundant explanation will be omitted. Hereinafter, the conveyance direction of the substrate (the left-right direction in FIG. 2) is referred to as the X direction, the direction orthogonal to the X direction in the horizontal plane (the left-right direction in FIG. 1) is the Y direction, and the direction perpendicular to the horizontal plane (the vertical direction in FIG. 1) is referred to as the Y direction. Defined as Z direction.

First, the structure of the printing apparatus 1 will be explained with reference to FIGS. 1 and 2. A substrate transport mechanism 2 is installed on the base of the printing apparatus 1 in the X direction. The printing device 1 includes a control section C. The substrate transport mechanism 2 is controlled by a control unit C, and transports the substrate 3 carried in from the upstream side in the X direction, holds the substrate 3 at a predetermined clamp position, and moves it up and down. Further, the substrate transport mechanism 2 carries out the substrate 3 on which printing work has been completed to the downstream side. The substrate 3 is a printing material to which a paste P such as solder paste, flux, conductive adhesive, silver paste, ink, etc. is transferred.

Above the substrate 3 held in the clamp position, there is a mask 4 having a plurality of openings 4a (see FIG. 5) provided at positions corresponding to the electrodes 3a (see FIG. 5) formed on the upper surface of the substrate 3. is set up. A print head 6 is provided above the mask 4 and is moved in the Y direction by a print head movement mechanism 5. The print head moving mechanism 5 includes a feed screw 7 extending in the Y direction and a motor 8 that rotationally drives the feed screw 7. The print head 6 includes a movable base 9 that has a thread that engages with the thread of the feed screw 7 and moves in the Y direction as the feed screw 7 rotates. The motor 8 is controlled by a control unit C, and by rotating the feed screw 7 in the forward or reverse direction, the print head 6 including the movable base 9 reciprocates in the Y direction.

In FIGS. 1 and 2, the print head 6 includes two lifting cylinders 10 arranged in the Y direction above a movable base 9. The lifting cylinders 10 raise and lower lifting shafts 11 that extend downward through the movable base 9, respectively. Holding parts 12 are provided at the lower ends of the lifting shafts 11, respectively. The holding parts 12 each hold the blades 13 at an angle with respect to the mask 4. Each blade 13 is inclined in the direction of sliding on the mask.

The two lifting cylinders 10 are controlled by a control section C. When printing the paste P on the substrate 3, the control section C controls the lifting cylinders 10 to lower one of the holding sections 12 and bring the blade 13 into contact with the mask 4 (see FIG. 1). Thereafter, the control unit C controls the print head moving mechanism 5 to move the print head 6 in a direction in which the blade 13 in contact with the mask 4 is inclined. Thereby, the blade 13 slides on the mask 4 and fills the opening 4a of the mask 4 with the paste P (see FIG. 5(a)).

In this way, the holding part 12 and the blade 13 constitute a squeegee 14 that prints the paste P on the substrate 3 by sliding on the mask 4 provided with the predetermined opening 4a. Thereafter, by separating the substrate 3 from the mask 4, the paste P is transferred (printed) onto the electrode 3a of the substrate 3 (see FIG. 5(c)).

Next, the detailed structure of the squeegee 14 will be described with reference to FIGS. 3 to 5. 3(a) and 3(b) are side views of the squeegee 14, and FIG. 3(b) is an enlarged view of the vicinity of the lower end of the squeegee 14. FIG. 4 is a front view of the squeegee 14 seen from the second main surface 13b side of the blade 13, which will be described later. FIG. 5A schematically shows how the blade 13 fills the opening 4a of the mask 4 with the paste P.

In FIGS. 3 and 4, the blade 13 is a plate made of a metal material (for example, stainless steel), and holds its upper end side while being inclined by a first inclination angle θ1 (θ1<90°) with respect to the mask 4. It is fixed to part 12. During printing, the squeegee 14 moves in the direction (printing direction) of the first main surface 13a of the two surfaces of the blade 13 facing the mask 4 (arrow b in FIG. 5(a)). That is, during printing, of the two surfaces of the blade 13, which is a metal plate material, the first main surface 13a facing the mask 4 contacts the paste P and moves the paste P in the printing direction.

Of the two surfaces of the blade 13, the second main surface 13b facing the first main surface 13a faces upward and does not move the paste P. The second main surface 13b has a softening section between the contact end 13c (lower end of the blade 13) where the blade 13 contacts the mask 4 and the holding section 12, from the second main surface 13b to the middle of the inside of the blade 13. A portion 13d is formed. That is, a softened portion 13d is formed in a portion of the second main surface 13b of the blade 13 that is not held by the holding portion 12 and is exposed.

In FIG. 4, the softened portion 13d is formed on the second main surface 13b along the width direction (X direction) of the blade 13 up to the left and right side surfaces 13e of the blade 13, parallel to the contact end portion 13c. The softened portion 13d is formed by linearly heating the second main surface 13b of the blade 13 with a laser beam or an electromagnetic heating device. By heating the metal blade 13, the properties of the softened portion 13d change and the hardness becomes lower than before heating. That is, the softened portion 13d is a low-rigidity portion where the rigidity of the blade 13 is lower than that of other portions. In this way, a linear softened portion 13d is provided in a part of the blade 13 along the width direction of the blade 13.

As shown in FIG. 5(a), when the squeegee 14 is lowered during printing and the contact end 13c of the blade 13 contacts the mask 4, when the squeegee 14 is further pushed down (arrow a), the blade 13 has a low rigidity. It is bent using the softened part 13d as a fulcrum. At this time, the second inclination angle θ2 that the lower end 13f of the blade 13 below the softened part 13d forms with the mask 4 is the attack angle, and the blade 13 is smaller than the first inclination angle θ1 at which the blade 13 is held by the holding part 12. Small (θ2<θ1). Then, the third inclination angle θ3 remaining after subtracting the second inclination angle θ2 from the first inclination angle θ1 is the angle at which the blade 13 bends with the softened portion 13d as a fulcrum.

Next, with reference to FIGS. 5(a) to 5(c), a process of printing paste P on the substrate 3 using the squeegee 14 will be described. In FIG. 5A, the squeegee 14 is pushed down to a state where the blade 13 is bent around the softened portion 13d and a predetermined printing pressure is applied to the mask (arrow a). When the predetermined printing pressure is reached, the squeegee 14 moves in the direction of the first main surface 13a (arrow b). Thereby, the blade 13 in contact with the mask 4 slides on the mask 4 while scraping up the paste P. When the bent lower end 13f of the blade 13 passes through the opening 4a in this process, the paste P is pushed into the opening 4a and filled therein.

When the movement of the mask 4 relative to one substrate 3 is completed, the squeegee 14 rises to its original height. When the squeegee 14 rises and the blade 13 separates from the mask 4, the restoring force of the blade 13 causes the blade 13 to return to the unbent state shown in FIG. 3(a). FIG. 5B shows a state in which the sliding of the squeegee 14 has been completed and each opening 4a of the mask 4 is filled with paste P. In FIG. 5C, when the substrate 3 is then lowered and separated from the mask 4 (arrow c), the paste P is transferred (printed) onto the electrode 3a of the substrate 3.

As described above, the squeegee 14 includes the metal blade 13 that fills the opening 4a with the paste P, and the holding portion 12 that holds the blade 13 at an angle with respect to the mask 4. A linear softened portion 13d is provided in a part of the blade 13 along the width direction of the blade 13. As a result, the solder paste (paste P) can be appropriately printed on the substrate 3, and the life span of the squeegee 14 can be extended.

Note that the length from the contact end 13c of the blade 13 to the softened part 13d (that is, the length of the lower end 13f of the blade 13) and the shape (size, depth, etc.) of the softened part 13d are determined by the markings at the time of printing. It is designed in consideration of the pressure, the viscosity of the paste P, the shape of the opening 4a of the mask 4, etc.

Next, with reference to FIG. 6, the structure of the second squeegee 15 attached to the printing apparatus 1 will be described. 6(a) and 6(b) are side views of the second squeegee 15, and FIG. 6(b) is an enlarged view of the vicinity of the lower end of the second squeegee 15. The second squeegee 15 has the same holding part 12 as the squeegee 14 shown in FIGS. 3 to 5, but has a different blade 16 structure. Hereinafter, the same structures will be denoted by the same reference numerals and detailed explanations will be omitted.

In FIGS. 6(a) and 6(b), the blade 16 has a first main surface 16a that contacts the paste P during printing, and a second main surface 16b that faces the first main surface 16a. have. In the blade 16 of the second squeegee 15, a linear softened portion 16c is formed along the width direction of the blade 16 on the first main surface 16a. The softened portion 16c is formed halfway inside the blade 16 from the first main surface 16a. As a result, like the blade 13, the blade 16 bends around the softened portion 16c, which is a low-rigidity portion, as a fulcrum during printing.

Next, with reference to FIG. 7, the structure of the third squeegee 17 attached to the printing apparatus 1 will be described. 7(a) and 7(b) are side views of the third squeegee 17, and FIG. 7(b) is an enlarged view of the vicinity of the lower end of the third squeegee 17. The third squeegee 17 has the same holding part 12 as the squeegee 14 shown in FIGS. 3 to 5, but has a different blade 18 structure.

In FIGS. 7(a) and 7(b), the blade 18 has a first main surface 18a that contacts the paste P during printing, and a second main surface 18b that faces the first main surface 18a. have. The blade 18 of the third squeegee 17 has a linear softened portion 18c formed along the width direction of the blade 18. The softened portion 18c is formed inside the blade 18 from the first main surface 18a to the second main surface 18b. As a result, like the blade 13, the blade 18 bends around the softened portion 18c, which is a low-rigidity portion, as a fulcrum during printing.

In this way, the printing apparatus 1 is equipped with one of the squeegee 14, the second squeegee 15, and the third squeegee 17, and prints the paste P on the substrate 3. The blades 13, 16, 18 have first main surfaces 13a, 16a, 18a that come into contact with the paste P during printing, and a second main surface 13b that faces the first main surfaces 13a, 16a, 18a. At least one of 16b and 18b is provided with softened portions 13d, 16c, and 18c. As a result, the solder paste (paste P) can be appropriately printed on the substrate 3, and the life span of the squeegee can be extended so that the squeegee can be used repeatedly.

In addition, although the substrate 3, such as a printed circuit board on which components are mounted, has been described as an example of the substrate on which the printing apparatus 1 prints the paste P, the substrate to be printed is not limited to the substrate 3. For example, the printing material may be clothing such as a T-shirt on which paste P such as ink is printed, glass, ceramics, or the like.

The squeegee and printing device of the present invention have the advantage that they can be used repeatedly and have a long life, and can properly print solder paste on a board, and are useful in the field of mounting components on a board.

1 Printing device 3 Substrate 4 Mask 4a Opening 12 Holding section 13, 16, 18 Blade 13a, 16a, 18a First main surface 13b, 16b, 18b Second main surface 13d, 16c, 18c Softening section 14 Squeegee 15 Second squeegee (squeegee)
17 Third squeegee (squeegee)
P paste

Claims (3)

A squeegee that prints paste on a substrate by sliding on a mask provided with predetermined openings,
a metal blade filling the opening with the paste;
a holding part that holds the blade at an angle with respect to the mask,
A part of the blade is provided with a linear softened part along the width direction of the blade ,
When the blade is further pushed down after the blade comes into contact with the mask, the blade bends using the softened part as a fulcrum, and the angle of inclination that the part of the blade below the softened part makes with the mask is the same as that of the blade. is smaller than the inclination angle held by the holding part . The softening portion includes a first main surface that comes into contact with the paste during printing;
The squeegee according to claim 1, wherein the squeegee is provided on at least one of the second main surface facing the first main surface. A printing device comprising the squeegee according to claim 1 or 2 and printing paste on the substrate.

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