JP2003025543A - Screen printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a screen printer in which filling properties and scrapability can be compatible. SOLUTION: The screen printer prints a paste on a base via pattern holes by moving a closed squeegee head on a mask plate 12. The printer comprises slide contacts 37 disposed at both ends of a lower surface of a body 30 of the squeegee head 13 and integrally coupling a scraping member 39 bringing into slide contact at its lower end with an upper end of the plate 12 to scrape a cream solder in squeezing to a filling member 38 for filling the solder in pattern holes by rolling the solder by a filling surface in squeezing and having a mounting surface 38a for mounting the member 39 and a filling surface 38b at a predetermined angle to the mounting surface. Thus, the filling properties and the scrapability can be compatible.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen printing apparatus for printing paste such as cream solder or conductive paste on a substrate. 2. Description of the Related Art In an electronic component mounting process, screen printing is used as a method for printing paste such as cream solder or conductive paste on a substrate. In this method, a mask plate in which pattern holes are opened according to a printing target portion is set on a substrate, and the paste is printed on the substrate through the pattern holes of the mask plate by squeezing. As a squeezing method for screen printing, a method using a closed squeegee head is known. This method differs from ordinary screen printing in that a paste is not directly supplied onto a mask plate, but a squeegee head in which paste is stored is used. In this method, the paste is sequentially filled into the pattern holes of the mask plate via the paste contact surface by moving the squeegee head while the paste contact surface provided on the lower surface of the squeegee head is in contact with the mask plate. Let it. [0004] However, the screen printing using the conventional closed squeegee head described above involves the following.
There were the following problems. In squeezing, while filling the pattern holes with paste,
It is necessary to scrape off the paste adhering to the upper surface of the mask plate.However, if the squeegee provided on the squeegee head is formed in a shape and mounting angle that satisfies the filling property, in general, good scraping properties cannot be obtained. Use of a squeegee having such a shape as to ensure removability has a contradictory property that the filling property is deteriorated. For this reason, the conventional screen printing apparatus using the closed squeegee head has a problem that it is difficult to achieve both the filling property and the scraping property. [0005] Therefore, an object of the present invention is to provide a screen printing apparatus capable of satisfying both the filling property and the scraping property. According to a first aspect of the present invention, there is provided a screen printing apparatus for printing a paste on a substrate through a pattern hole of a mask plate by moving a squeegee head on the mask plate. An apparatus, wherein the squeegee head is moved in a horizontal direction with respect to the mask plate, and horizontal moving means for moving up and down,
Lifting and lowering means, pressing means for pressing the squeegee head against the mask plate, a printing space provided in the squeegee head, containing a paste and contacting the surface of the mask plate through an opening formed on the lower surface, Comprising two opposed sliding contact portions that form front and rear walls in the squeezing direction of the printing space and that are in sliding contact with the upper surface of the mask plate;
The sliding contact portion is a scraping member that scrapes off the paste on the upper surface of the mask plate during squeezing, the lower end portion being made of a flexible plate member that slides on the upper surface of the mask plate,
It consists of a flexible block-shaped member having a mounting surface on which the scraping member is mounted and a filling surface forming a predetermined angle with respect to the mounting surface. And a filling member to be filled into the body. According to the present invention, two slidable portions which slidably contact the upper surface of the mask plate are formed of a flexible plate member whose lower end portion slidably contacts the upper surface of the mask plate. A scraping member for scraping off, a flexible block-shaped member having a mounting surface on which the scraping member is mounted and a filling surface forming a predetermined angle with respect to the mounting surface. By forming a structure in which the paste is rolled and integrally joined with a filling member for filling the pattern holes, the filling property and the scraping property can be compatible. Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a front view of a screen printing apparatus according to an embodiment of the present invention, FIG. 2 is a side view of the screen printing apparatus according to an embodiment of the present invention, and FIGS. 3, 4, 5, and 7 are views of the present invention. FIG. 6 is a partial cross-sectional view of a squeegee head of a screen printing apparatus according to an embodiment of the present invention. FIG. 6 is an explanatory diagram of an operation of the squeegee head in screen printing according to an embodiment of the present invention. First, the structure of the screen printing apparatus will be described with reference to FIGS. 1 and 2, the substrate positioning section 1 is configured by disposing a substrate holding section 2 on a moving table (not shown). The substrate 3 to be screen-printed is held by the clamper 4 of the substrate holding unit 2, and by driving the moving table, the substrate holding unit 2 is moved.
Is held in the horizontal and vertical directions. A screen mask 10 is provided above the positioning section 1. The screen mask 10 is configured by mounting a mask plate 12 on a holder 11, and a pattern hole 12 a corresponding to a printing portion of the substrate 3 to be printed is formed in the mask plate 12. A squeegee head 13 is provided on the screen mask 10 so as to be able to move up and down by a head elevating unit 20. The head elevating unit 20 includes a cylinder 22 erected on a plate member 21. The squeegee head 13 is connected to the lower end of the rod 22 a of the cylinder 22 via a connecting member 15. By driving the cylinder 22, the squeegee head 13 moves up and down with respect to the mask plate 12, and presses the squeegee head 13 against the mask plate 12. The head elevating unit 20 is a squeegee head 1
3 serves as an elevating means for elevating the screen mask 3 with respect to the screen mask 10. The cylinder 22 is a squeegee head 1
3 is a pressing means for pressing the mask plate 3 against the mask plate 12. Sliders 23 are fixed at both ends to the lower surface of the plate member 21 of the head elevating unit 20, and the slider 23 is slidably fitted on a guide rail 24 provided on the upper surface of the frame 25. I have. A nut 26 is coupled to the lower surface of the plate member 21, and a feed screw 27 screwed to the nut 26 is driven to rotate by a motor 28. By driving the motor 28, the plate member 21 moves horizontally, and therefore the head lifting / lowering unit 20 is moved.
Also moves horizontally. By driving the motor 28 with the squeegee head 13 lowered, the squeegee head 13 moves horizontally on the mask plate 12. That is, the motor 28, the feed screw 27, and the nut 26 serve as horizontal moving means for horizontally moving the squeegee head 13 on the mask plate 12. At the lower part of the squeegee head 13, there is provided a printing section 14 which abuts on the surface of the mask plate 12 and fills the pattern holes 12a with the cream solder 5 as a paste. The structure of the printing unit 14 will be described with reference to FIG. In FIG. 3, reference numeral 30 denotes a main body, which is a block-shaped member that is elongated in the width direction of the mask plate 12. The length of the main body 30 is set so as to cover the width of the substrate 3 to be printed as shown in FIG. Main unit 30
Is formed with a concave portion 30a in which a cartridge 31 in which the cream solder 5 is stored is detachably mounted. The cartridge 31 is a reservoir (paste reservoir) for the cream solder 5 in which a predetermined amount of the cream solder 5 is stored in advance, and is mounted on the main body 30 at the time of printing. A pressure plate 32 for pressing the cream solder 5 inside is fitted into the opening on the upper surface of the cartridge 31. The pressure plate 32 is connected to the rod 16 a of the cylinder 16 arranged above, and by driving the cylinder 16,
The pressure plate 32 moves up and down in the cartridge 31. The cylinder 16 is connected to an air source 18 via a valve V and a regulator R. The regulator R can set the pressure of the air supplied to the cylinder 16 according to the pressure setting signal from the control unit 19, and pushes down the cream solder 5 in the cartridge 31 with a predetermined pressure. The bottom of the cartridge 31 has a cream solder 5
The extruding plate 31a has a large number of openings 31b. When the pressing plate 32 is pressed downward by the cylinder 16, the cream solder 5 in the cartridge 31 is pressed, and the pressing plate 31a is pressed.
Through the opening 31b. Cylinder 1
The pressing plate 6 and the pressing plate 32 serve as a paste pressing means for pressing the cream solder 5 which is a paste. The control of the pressurization at this time is performed by controlling the valve V and the regulator R by the control unit 19. At the bottom of the main body 30, a cartridge 31 is provided.
A diaphragm plate 34 provided with a large number of openings 34a is mounted similarly to the extrusion plate 31a. When the cream solder 5 is extruded by the cylinder 16, the extruding plate 3
It passes through the opening 31b of 1a and the opening 34a of the diaphragm plate 34 in two stages and moves downward. The extruded cream solder 5 enters a space formed below the main body 30, that is, a printing space 35 surrounded by a squeegee 36 provided on the lower surface of the main body 30 and the lower surface of the main body 30. To reach. In the movement path of the cream solder 5, the pressure of the cream solder 5 passes through the many small openings 31b and 34a, so that the viscosity of the cream solder 5 is reduced and the solder 5 is modified into a property suitable for screen printing. Next, the squeezing section 36 and the printing space 35 will be described with reference to FIG. Squeezing part 3
Reference numeral 6 denotes a lower surface of the main body 30, which is formed of four wall surfaces that surround the periphery, and a printing space 3 is provided inside these wall surfaces.
5 are formed. As shown in FIG.
At both ends in the squeezing direction (the direction of arrow a), two sliding contact portions 37 forming front and rear wall surfaces of the printing space 35 are provided. At the time of the printing operation, the printing space 35 contains the pressurized cream solder 5, and the cream solder 5 is supplied to the mask plate 12 through the lower surface of the printing space 35, that is, the opening formed between the two sliding contact portions 37. Contact surface. The sliding contact portion 37 has a configuration in which a plate-shaped scraping member 39 and a block-shaped filling member 38 are combined and integrally connected. The scraping member 39 is provided in the printing space 3.
5 is in sliding contact with the upper surface of the mask plate 12 at an obtuse angle α. Here, the detailed shape of the sliding portion 37 will be described with reference to FIG. The scraping member 39 is a flexible plate member whose lower end 39a is in sliding contact with the upper surface of the mask plate 12, and scrapes the cream solder 5 on the upper surface of the mask plate 12 during squeezing. The filling member 38 includes a mounting surface 38a on which the scraping member 39 is mounted, and the mounting surface 38a.
And a filling surface 38b forming an acute angle γ with respect to the upper surface of the mask plate 12 located in the printing space 35 at a predetermined angle β, and a substantially square block shape made of a flexible material such as an elastomer. Is formed. The filling member 38 causes the cream solder 5 to roll by the filling surface 38b during squeezing, and fills the pattern holes 12a. As shown in FIG. 5A, the scraping member 3
9, the lower end 39a of the filling member 38 projects downward slightly below the lower end 38c of the filling member 38.
Is kept in contact with the mask plate 12, the lower end 39a of the scraping member 39 must be
To contact the upper surface. When the printing pressure is applied to the squeegee head 13, the sliding contact 37 is pressed against the mask plate 12, whereby the sliding contact 37 is deformed by the load as shown in FIG. Then, the filling surface 38b is deformed into a curved shape and deformed into a shape suitable for imparting a rolling property to the cream solder 5, and the scraping member 39 is bent into a downwardly convex shape, which is suitable for scraping the cream solder 5. Deformed into the shape. In this embodiment, the scraping member 39
Although the lower end portion 39a of the scraping member 39 is shown in a state where the lower end portion 39a of the
If the combination of the dimensions and materials of the scraping member 39 and the filling member 38 is set so that the bottom surface 39a of the filling member 38 does not protrude, 38c may be aligned. The screen printing operation by the squeegee head 13 will be described. When the squeegee head 13 is moved in the direction of arrow b in a state where the cream solder 5 is pushed out from above and filled in the printing space 35 as shown in FIG. Among them, the rolling flow as shown by the arrow c is given to the cream solder 5 located near the front surface of the sliding contact portion 37 by the filling surface 38b. Thereby, during the movement of the squeegee head 13, the cream solder 5 enters the pattern holes 12a of the mask plate 12 and fills the inside well. FIG. 6B shows a state where the cream solder 5 attached to the upper surface of the mask plate 12 is scraped off by the scraping member 39. That is, the portion where the sliding contact portion 37 comes into contact with the mask plate 12 is a scraping member 39 having a shape suitable for scraping the cream solder 5, and the sliding contact portion 37 is pressed against the surface of the mask plate 12. When the squeegee head 13 moves in a state where the squeegee head 13 is moved, the cream solder 5 is scraped off from the surface of the mask plate 12. The configuration of the sliding contact portion is similar to the sliding contact portion 37 'shown in FIG.
8 ′ may be configured to be detachable and detachable. In this configuration example, a mounting surface 40a of a scraping member 39 ', a mounting surface 40b of a pressing member 40' of a filling member 38 'and a mounting block 40 provided with a locking claw portion 40c are mounted on the lower surface of the main body 30. . When the sliding portion 37 'is mounted, the filling member 3
The scraping member 39 ′ is fixed to the mounting surface 40 a by the holding plate 41 and the bolt 42 while the 8 ′ is sandwiched between the pressing surface 40 b and the scraping member 39 ′. By adopting such a configuration,
The scraping member 39 'and the filling member 38' are separated and can be individually replaced as needed during maintenance. According to the present invention, the two sliding contact portions sliding on the upper surface of the mask plate and the flexible plate member having the lower end sliding on the upper surface of the mask plate are used for masking in squeezing. In squeegeeing, a scraping member for scraping the paste on the upper surface of the plate, a flexible block-shaped member having a mounting surface on which the scraping member is mounted, and a filling surface forming a predetermined angle with respect to the mounting surface. Since the paste is rolled by the filling surface and the filling member for filling the pattern holes is integrally connected, the filling property and the scraping property can be made compatible.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of a screen printing apparatus according to an embodiment of the present invention. FIG. 2 is a side view of a screen printing apparatus according to an embodiment of the present invention. FIG. 4 is a partial cross-sectional view of a squeegee head of the screen printing apparatus according to one embodiment of the present invention. FIG. 4 is a partial cross-sectional view of a squeegee head of the screen printing apparatus of one embodiment of the present invention. FIG. 6 is a partial cross-sectional view of the squeegee head of the printing apparatus. FIG. 6 is an explanatory diagram of the operation of the squeegee head in screen printing of one embodiment of the present invention. FIG. 7 is a part of the squeegee head of the screen printing apparatus of one embodiment of the present invention. Cross-sectional view [Description of Signs] 3 Substrate 5 Cream solder 12 Mask plate 12a Pattern hole 13 Squeegee head 20 Head elevating part 35 Printing space 36 Squeezing part 37 Sliding contact part 3 Scraping member filling member 38b filling surface 39

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Ryo Maeda             Matsushita Electric, 1006 Kadoma, Kazuma, Osaka             Sangyo Co., Ltd. (72) Inventor Hirotoshi Sakamoto             Matsushita Electric, 1006 Kadoma, Kazuma, Osaka             Sangyo Co., Ltd. F term (reference) 2C035 AA06 FA31 FB24 FC08 FD05                       FD17 FD35 FD37 FD42                 5E319 AC01 BB05 CD29

Claims (1)

Claims: 1. A screen printing apparatus for printing a paste on a substrate through a pattern hole of a mask plate by moving a squeegee head on the mask plate, wherein the squeegee head is mounted on the mask plate. A horizontal moving means for moving and raising and lowering the squeegee head against the mask plate, and an opening provided on the squeegee head for receiving paste and formed on the lower surface. A printing space that is in contact with the surface of the mask plate via a portion, and two opposed sliding contact portions that form front and rear walls in the squeezing direction of the printing space and that are in sliding contact with the upper surface of the mask plate; The contact portion is made of a flexible plate-like member whose lower end portion is in sliding contact with the upper surface of the mask plate, and has a A ski comprising a scraping member for scraping the paste on the upper surface of the plate, a flexible block-shaped member having a mounting surface on which the scraping member is mounted, and a filling surface forming a predetermined angle with respect to the mounting surface. A screen printing apparatus, wherein a filling member for rolling the paste by the filling surface and filling the inside of the pattern hole in the jing is integrally formed.