JPH06126929A - Screen printing method and machine - Google Patents

Abstract

PURPOSE:To stably enable sharp printing even at a fine place by eliminating the blur or running at a printing place. CONSTITUTION:Solder paste 6 is applied and transferred to the surface 7a to be printed of a printed wiring board through a screen 4 having printing patterns drawn thereon to perform printing. In this printing method, a chuck table 3 enabling the surface 7a to be printed of the printed wiring board 7 to come into contact with and to separate from the screen 4 at an almost right angle to hold the printed wiring board 7 in a releasable manner and the printing table 10 arranged so as to freely come into contact with the rear of the screen 4 outside the chuck table 3 are provided. The printed wiring board is separated from the screen through the movement of the chuck table 3 in such a state that the printing table is brought into contact with the rear of the screen 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen printing method used for printed wiring boards and the like and a screen printing machine using the method.

[0002]

2. Description of the Related Art A screen is used for pattern printing, solder resist printing, numbering printing, through-hole printing in the circuit forming process of a printed wiring board, cream solder printing in the mounting process, and exterior (chassis, name plate, operation panel) printing. Printing or the like is used, and many screen printing machines have been proposed.

FIG. 6 is a sectional view schematically showing an example of a conventional screen printer for a printed wiring board.
Referring to FIG. 6, the screen printing machine is mainly composed of a squeegee block 101 and a screen body 1 for printing.
02, chuck table 103.

More specifically, the screen body 102
Is a sheet-shaped screen 1 on which a print pattern is drawn.
04 and a frame portion 105 that holds the screen 104 to hold it. In addition, screen 1
In 04, the print pattern is shown by a groove-shaped opening 104a penetrating vertically, and the solder paste 106 applied to one surface (front surface) side can be transferred to the other surface (back surface) side through this groove-shaped opening 104a. There is.

The chuck table 103 moves so that the printed wiring board 107 as a printed matter is releasably held and the printed surface 107a of the printed wiring board 107 can be brought into contact with and separated from the back surface of the screen 104 at a substantially right angle. It is arranged as possible.

The squeegee block 101 is a screen 1
04, a squeegee 108 for applying the solder paste 106 while extracting it, and a squeegee holder 109 holding the squeegee 108. Of these, the squeegee 108 is formed with a width that allows it to move while tracing the left and right image areas formed on the screen 104. When printing the solder paste 106,
The squeegee 108 is moved integrally with the squeegee holder 109 from one side of the screen 104 to the other side, that is, in the front-rear direction while extracting the solder paste 106, and at this time, the squeegee is transferred to the back side through the groove-shaped opening 104a.

Next, the operation of the screen printing machine configured as described above will be described. First, in printing, the chuck table 103 that chucks the printed wiring board 107 is
The printed surface 107a of the printed wiring board 107 is the screen 10
It is raised until it comes into close contact with the back surface of No. 4 and waits.

Next, the squeegee 108 is attached to the screen 10.
4 is lowered together with the squeegee holder 109 until it comes into contact with the surface of the squeegee 4 (this state is drawn by the one-dot chain line in FIG. 6), and then the squeegee holder 10 is scratched while scraping the solder paste 106.
It moves from one side to the other side together with 9, and stops and waits on the other side (this state is shown by the solid line in FIG. 6). Then, when the squeegee 108 moves, the groove-shaped opening 104 a of the screen 104 is filled with the solder paste 106, and the solder paste 106 is attached to the printed surface 107 a of the printed wiring board 107.

After that, the chuck table 103 slowly descends together with the printed wiring board 107 at a predetermined speed and separates in a direction perpendicular to the screen 104. Further, at this time, the solder paste 10 filled in the groove-shaped opening 104a
6 is pulled out from the groove-shaped opening 104a in a state of being attached to the surface to be printed, transferred to the surface to be printed, and printing is completed. On the other hand, the squeegee 108 rises together with the squeegee holder 109,
stand by. After printing, the printed wiring board 107 on the chuck table 103 is replaced, a new printed wiring board 107 is set, and the solder paste 106 is printed in the same manner.

[0010]

However, in the above-described conventional screen printing machine, the solder paste 1 is used.
Prior to the application of 06, the squeegee 108 descends together with the squeegee holder 109 to come into contact with the surface of the screen 104. The screen 104 is stretched with a certain tension and is flexible, so that the squeegee 10
8 may be abutted against the printed wiring board 107 via the screen 104 in a state in which it can be pushed below the surface of the screen 104. In such a case, when the movement of the squeegee 108 accompanying the application of the solder paste 106 is completed and the chuck table 103 is gently lowered together with the printed wiring board 107, a part of the screen 104 is pushed by the squeegee 108 accordingly. As a result, it is bent as shown in FIG. Then, the separation of the solder paste 106 filled in the groove-shaped opening 104a becomes unstable, and as shown in FIG. 8, the solder paste 106 transferred to the printed wiring board 107 has sagging or bleeding and the shape is unstable. become. For this reason, a clear pattern cannot be printed, and printing of a high-quality solder paste corresponding to an electronic component that is miniaturized at a narrow pitch cannot be obtained, which is a problem in terms of quality.

The present invention has been made in view of the above-mentioned problems, and an object thereof is a screen printing method capable of eliminating bleeding and sagging in a printing portion and stably and vividly printing even in a fine portion. It is to provide a screen printing machine using the method.

[0012]

In order to achieve the above object, the present invention is to apply a paste-like material to a printing surface of a printed matter through a screen on which a printing pattern is drawn, and transfer the paste-like material to perform printing. A first mechanism for holding the printed matter in a releasable manner by allowing the printed surface to come into contact with and separate from the screen at a substantially right angle, and the first mechanism slidably holding the first mechanism. Second mechanism disposed so as to be freely contactable with the back surface of the screen on the outside of the second mechanism, and the first mechanism is in a state where the second mechanism is in contact with the back surface of the screen. The printed matter is separated from the screen through the movement of.

[0013]

According to this, since the printed matter is separated from the screen through the movement of the first mechanism in the state where the second mechanism is in contact with the back surface of the screen, the screen is separated when the printed matter is separated from the screen. It does not move and bend, and the paste-like material can be separated from the screen in a stable manner, eliminating the bleeding and sagging that has been a problem in the past, and enabling large-scale continuous and clear printing over a long period of time. It will be possible.

[0014]

Embodiments of the present invention will be described in detail below with reference to the drawings. 1 to 5 are sectional views schematically showing a screen printer for a printed wiring board shown as an embodiment of the present invention. 1 to 5, the screen printing machine is roughly composed of a squeegee block 1 for printing, a screen body 2, a chuck table 3 as a first mechanism, and a printing table 10 as a second mechanism. ing.

More specifically, the screen body 2 is composed of a sheet-like screen 4 on which a print pattern is drawn, and a frame portion 5 which holds the screen 4 and holds it. In the screen 4, the print pattern is shown by a groove-shaped opening 4a penetrating vertically, and the solder paste 6 applied to one surface (front surface) side can be transferred to the other surface (back surface) side through this groove-shaped opening 4a. It is in a state of.

The chuck table 3 releasably holds a printed wiring board 7 as a printed matter.

The printing table 10 is the chuck table 3
The surface to be printed 7a of the printed wiring board 7 held by is placed in a state in which it can come into contact with and separate from the back surface of the screen 4 at a substantially right angle, and is held movably outside the chuck table 3. In the chuck table 3, the printed surface 7 a of the printed wiring board 7 held by the chuck table 3 is the upper surface 10 of the printing table 10.
It is displaceable between a printing position (see FIGS. 1, 2 and 5) that is substantially flush with a and a position (see FIG. 4) that is lower than this.
Further, the printing table 10 itself can reciprocate integrally with the chuck table 3 in the vertical direction, that is, in the direction in which the printing table 10 can be brought into and out of contact with the back surface of the screen 4 at a substantially right angle.

The squeegee block 1 is a squeegee 8 that is applied onto the screen 4 while extracting the solder paste 6.
And a squeegee holder 9 holding the squeegee 8. Of these, the squeegee 8 is formed with a width that allows it to move while tracing the left and right image areas formed on the screen 4. When the solder paste 6 is printed, the squeegee 8 is moved integrally with the squeegee holder 9 from one side of the screen 4 to the other side, that is, in the front-rear direction while extracting the solder paste 6, and at this time, through the groove-shaped opening 4a. Transferred to the back side.

Next, the operation of the screen printing machine thus constructed will be described in order from FIG. 1 to FIG. First,
In printing, the chuck table 3 chucking the printed wiring board 7 is moved and held in the printing table 10 until the printed surface 7 a of the printed wiring board 7 is substantially flush with the upper surface 10 a of the printing table 10. It Then, in this state, the printing table 10 is lifted and waits until the printed surface 7a of the printed wiring board 7 and the upper surface 10a of the printing table 10 come into close contact with the back surface of the screen 4.

Next, the squeegee 8 is lowered together with the squeegee holder 9 until it comes into contact with the surface of the screen 4 (see FIG. 1).
Then, while pouring out the solder paste 6, it is moved from one side to the other side together with the squeegee holder 9,
The other side stops and stands by (see FIG. 2). Then, when the squeegee 8 is moved, the groove-shaped opening 4a of the screen 4 is filled with the solder paste 6, and the solder paste 6 is attached to the printed surface 7a of the printed wiring board 7.

Thereafter, the print table 10 is displayed on the screen 4
The chuck table 3 slowly moves down in the printing table 10 at a predetermined speed together with the printed wiring board 7 while remaining in contact with the back surface of the printing plate 10 and separates in a direction perpendicular to the screen 4 (see FIG. 3). Further, at this time, the solder paste 6 filled in the groove-shaped opening 4a is extracted from the groove-shaped opening 4a in a state of being attached to the surface 7a to be printed, and transferred to the surface 7a to be printed to complete printing (FIG. 4). reference).

On the other hand, the squeegee 8 rises together with the squeegee holder 9 and is returned to the initial position to stop and stand by. Simultaneously with this operation, the printing table 10 remains separated from the back surface of the screen 4 and does not move, only the chuck table 3 ascends in the printing table 10 together with the printed wiring board 7, and the printed wiring board 7 tops the printing table 10. 10a
And is returned to the same level (see FIG. 5). Thereafter, the printed printed wiring board 107 is removed, a new printed wiring board 107 is set, the same operation is repeated, and printing is sequentially performed.

Therefore, according to this embodiment, since the printed wiring board 7 is separated from the screen 4 together with the chuck table 3 in the state where the printed table 10 is in contact with the back surface of the screen 4, the printed wiring board 7 is moved to the screen 4. When the screen 4 is further separated, the screen 4 does not move and bend, and the solder paste 6 as a paste-like material can be separated from the screen 4 in a stable manner. It is possible to print in large quantities continuously over a long period of time without losing clarity.

In the above embodiment, the screen printing machine for printing the solder paste 6 on the printed wiring board 7 has been described, but the present invention is not limited to the printed wiring board and can be applied to the case of printing on another printing unit. Further, the printed matter is not limited to the solder paste and may be other paste-like material such as ink.

[0025]

As described above, according to the present invention,
Since the printed matter is separated from the screen through the movement of the first mechanism while the second mechanism is in contact with the back surface of the screen, the screen may move and bend when the printed matter separates from the screen. The paste-like material can be separated from the screen in a stable manner, eliminating the bleeding and sagging that has been a problem in the past, and enabling a large amount of continuous vivid printing over a long period of time, improving print quality. To do.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a main part of a screen printing machine as an embodiment of the present invention as viewed from the front direction.

FIG. 2 is a diagram illustrating the operation of the main part of the above screen printing machine shown as the present embodiment.

FIG. 3 is an operation explanatory diagram of a main part of the same screen printing machine as the present embodiment.

FIG. 4 is a diagram illustrating the operation of the main part of the above screen printing machine according to the present embodiment.

FIG. 5 is a diagram illustrating the operation of the main parts of the above screen printing machine according to the present embodiment.

FIG. 6 is a cross-sectional view showing a main part of a conventional screen printing machine as viewed from the front direction.

FIG. 7 is a cross-sectional view illustrating a problem of a conventional screen printing machine.

FIG. 8 is a cross-sectional view illustrating a problem of a conventional screen printing machine.

[Explanation of symbols]

 1 Squeegee Block 2 Screen Body 3 Chuck Table (First Mechanism) 4 Screen 4a Groove Opening 6 Solder Paste (Paste Material) 7 Printed Wiring Board (Printed Material) 7a Printed Surface 8 Squeegee 10 Printing Table (Second Mechanism) )

Claims (4)

[Claims] 1. A screen printing method in which a paste-like material is applied onto a printing surface of a printed matter through a screen on which a printing pattern is drawn, and the printing is performed by transferring the paste-like material to the printing surface. A first means for holding the printed material in a releasable manner, a first means for slidably holding, and an outer side of the first means for abutting contact with the back surface of the screen. And a second means provided, wherein the printed material is separated from the screen through movement of the first means in a state where the second means is in contact with the back surface of the screen. A screen printing method characterized by. 2. A printed wiring board is used as a printed matter,
The screen printing method according to claim 1, wherein a solder paste is used as the paste material. 3. A screen printing machine, wherein a paste-like material is applied onto a printing surface of a printed matter through a screen on which a printing pattern is drawn, and the printing is performed by transferring the paste-like material to the printing surface. A first mechanism capable of holding the printed material in a releasable manner, and a first mechanism slidably held and capable of abutting against the back surface of the screen outside the first mechanism. And a second mechanism that is disposed as a screen printing machine. 4. A printed wiring board is used as a printed matter,
The screen printing machine according to claim 3, wherein a solder paste is used as the paste material.