JP3489463B2 - Screen printing device and printing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen printing apparatus and a screen printing method for printing cream solder on a thin substrate such as a flexible substrate.

[0002]

2. Description of the Related Art Prior to a mounting process for mounting electronic components on a board, cream solder is applied to the surface of the board. A method using screen printing is widely used as a method for applying cream solder. In this screen printing, a screen mask provided with a pattern hole only in the area where the cream solder is printed is set on the upper surface of the substrate, and the cream solder supplied onto the screen mask is scraped by a squeegee to pass through the pattern hole. The cream solder is printed.

By the way, in recent years, thin substrates such as flexible substrates have been used. Since this thin substrate is easily bent and difficult to handle as it is, it is generally handled while mounted on a pallet. The mounting on the pallet is performed by fitting the positioning holes of the thin board to the positioning pins provided on the pallet. Also in the screen printing process described above, the thin substrate is supplied to the screen printing apparatus in a state of being positioned on the pallet by the positioning pins. Then, a screen mask is set on the upper surface of the thin substrate mounted on the pallet, and printing is performed.

When setting the screen mask, it is necessary to bring the upper surface of the thin substrate into close contact with the lower surface of the screen mask. However, in the case of a thin substrate having a small thickness, the protrusion allowance of the positioning pin cannot be made equal to or less than the thickness of the substrate, and the substrate is positioned with the positioning pin protruding from the upper surface. In this state, the screen mask abuts on the positioning pins and cannot be brought into close contact with the substrate.Therefore, in the conventional case where a thin substrate is targeted, there is no choice but to escape by embossing etc. to the position where the screen mask positioning pins abut. It was dealt with by providing.

[0005]

However, only the upper surface of the embossed screen mask is not smoothed, and good printing may be hindered by the pattern holes provided in the vicinity. At the same time, the squeegee is constantly in contact with this convex portion and is damaged, which shortens the life of the component. As described above, in the conventional screen printing, when a thin substrate is targeted, a special screen mask subjected to embossing or the like is necessary, and further, there is a problem that print quality and component durability are deteriorated. there were.

Therefore, an object of the present invention is to provide a screen printing apparatus and a screen printing method which can use a normal screen mask even on a thin substrate and can secure printing quality.

[0007]

According to another aspect of the present invention, there is provided a screen printing apparatus including a movable table and a movable table.
Hold the pallet with the thin substrate mounted on it
It is provided with a moving holder and a moving table in between.
The first transfer unit for transferring pallets with thin substrates
The pallet is provided with a hole , the hole is formed in the pallet, the hole is slidably inserted into the pallet to project from the upper surface of the pallet, and the pallet is fitted into a positioning hole provided in the thin substrate. wherein a positioning pin for positioning the thin substrate, provided with a biasing means for biasing the positioning pins provided on the lower surface of the pallet upwardly Te.

The screen printing method according to claim 2,
A screen printing method for cream solder using the screen printing device according to claim 1 , wherein the first transport conveyor is provided.
Moves the pallet with thin board mounted on the holder
And hold it in the holder and drive the moving table
Then, the thin substrate on the pallet is against the screen mask
Positioning process and mask plate on top of thin substrate
Abut on the mask plate with the positioning pin.
Pressing down process and moving the squeegee to
Clean the upper surface of the thin substrate through the pattern hole of the lean mask.
The process of printing ream solder and mask play of a thin substrate
The positioning pin acts as a biasing means by separating it from the bottom surface of the
Push it up further and fit it perfectly into the positioning hole of the thin board.
And the pallet from the holder to the second conveyor
Discharging further downstream .

According to the invention described in each claim, a positioning pin fitted in a positioning hole formed in the thin substrate is slidably provided on the pallet, and is biased upward by a biasing means to form a screen mask. Since the positioning pin is pushed downward at the time of contact, a normal screen mask can be used without requiring special processing for releasing the positioning pin.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. 1 is a perspective view of a screen printing apparatus according to an embodiment of the present invention, FIG. 2 is a partial sectional view of the screen printing apparatus, and FIGS. 3A, 3B, and 3C are steps of the screen printing method. FIG.

First, the structure of the screen printing apparatus will be described with reference to FIG. In FIG. 1, a screen printing device 1
Has a moving table 2. The moving table 2 is composed of an X table 3 having an X axis motor 4 and a Y table 5 having a Y axis motor 6.

A holder 7 is arranged on the upper surface of the Y table 5. The holder 7 holds the pallet 8 and moves up and down by an up / down moving mechanism (not shown). On the upper surface of the pallet 8,
The thin substrate 9 is mounted, and the thin substrate 9 is positioned by fitting the positioning pins into the positioning holes formed in the thin substrate 9.

With the moving table 2 in between, the first and
The second transfer conveyors 11 and 12 are provided, and the pallet 8 on which the thin substrate 9 is preliminarily mounted is transferred from the first transfer conveyor 11 to the holder 7, and the pallet 8 after the printing operation is completed is the second pallet. It is discharged by the conveyor 12.

A screen mask 20 is arranged above the moving table 2. As shown in FIG. 2, the screen mask 20 has a mask plate 22 mounted on a frame portion 21, and the mask plate 22 has pattern holes 23 corresponding to the electrode positions of the thin substrate 9 to be printed. . A squeegee 24 is arranged on the upper surface of the mask plate 22 so that its lower end portion is in sliding contact with the upper surface of the mask plate 22 and is slidable in the horizontal direction. While the cream solder 25 is being supplied onto the mask plate 22, the print object is brought into close contact with the lower surface of the mask plate 22, and the cream solder 25 is scraped by the squeegee 24, so that the cream solder 25 is masked through the pattern holes 23. Plate 22
Is printed on the lower surface of the print target.

Next, the pallet 8 on which the thin substrate 9 is mounted
Will be described. As shown in FIG. 2, the pallet 8 is provided with a hole 8a, and the positioning pin 10 is slidably inserted into the hole 8a. The positioning pin 10 projects upward from the upper surface of the pallet 8 and fits into a positioning hole provided in the thin substrate 9 to position the thin substrate 9.

The lower end of the positioning pin 10 is a dish-shaped stepped portion 10a, and the stepped portion 10a is urged upward by a leaf spring 13 fixed to a bolt 14 on the lower surface of the pallet 8. As a result, the stepped portion 10a is pressed against the lower surface of the pallet 8, and in this state, the upper end portion of the positioning pin 10 projects from the upper surface of the thin substrate 9. That is, the leaf spring 13 serves as a biasing means for the positioning pin 10.

The screen printing apparatus is constructed as described above, and its operation will be described below. First, in FIG. 1, the pallet 8 to which the thin substrate 9 is attached in advance is moved from the transport conveyor 11 onto the holder 7 and held. Next, by driving the moving table 2, the thin substrate 9 on the pallet 8 is positioned with respect to the screen mask 20.

Next, as shown in FIG. 3A, the holder 7
The pallet 8 held on the screen rises with respect to the screen mask 20. At this time, the cream solder 25 is supplied onto the mask plate 22. Next, as shown in FIG. 3B, the upper surface of the thin substrate 9 contacts the mask plate 22, but the positioning pin 10 is pushed by the mask plate 22 because it is in the state of being biased by the leaf spring 13. The upper ends of the positioning pins 10 do not protrude from the upper surface of the thin board 9.

By moving the squeegee 24 in the direction of the arrow in this state, the cream solder 25 is scraped by the squeegee 24 and printed on the upper surface of the thin substrate 9 through the pattern holes 23. At this time, since the positioning pin 10 does not protrude from the upper surface of the thin substrate 9 as described above, the mask plate 22 does not need to be embossed for escape at the position of the positioning pin 10, and is used for a normal substrate. The same mask plate as that used can be used.
For this reason, the upper surface of the mask plate 22 is a completely smooth surface without any convex portion due to embossing or the like, and a printing defect that is likely to occur in a pattern hole near the convex portion or a squeegee 24 coming into contact with the convex portion occurs. It is possible to prevent damage to the squeegee due to wear.

Next, as shown in FIG. 3C, the holder 7 is lowered to move the thin substrate 8 to the mask plate 2
Separate from the bottom surface of 2. As a result, the cream solder 25 in the pattern hole 23 comes off the plate, and the printing on the thin substrate 9 is completed. At this time, the positioning pin 10 is pushed up by the leaf spring 13 and completely fits into the positioning hole of the thin substrate 9 to fix the position. After this, the pallet 8 is placed in the holder 7
Is transferred to the transport conveyor 12 and discharged downstream.
Even during this discharging operation, since the positioning pin 10 is completely fitted in the positioning hole of the thin board 9 as described above, the positional deviation does not occur during the transportation, and the electronic component mounting step of the next step is also performed. Similarly, it is possible to prevent a defect due to a position shift.

[0021]

According to the present invention, a positioning pin that fits into a positioning hole formed in a thin substrate is slidably provided on a pallet, and is biased upward by a biasing means to abut against a screen mask. Since the positioning pin is sometimes pushed downward, the screen mask does not require a special process for escaping the positioning pin, a normal screen mask can be used, and the facility cost can be reduced. Also, the pallet discharge operation by the second conveyor
Even when the positioning pin is in the positioning hole of the thin board
As they are completely fitted, there will be no misalignment during transportation.
Similarly, it is not positioned in the next electronic component mounting process as well.
It is possible to prevent problems caused by this.

[Brief description of drawings]

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

FIG. 2 is a partial cross-sectional view of the screen printing apparatus according to the embodiment of the present invention.

FIG. 3A is a process explanatory diagram of a screen printing method according to an embodiment of the present invention. FIG. 3B is a process explanatory diagram of a screen printing method according to an embodiment of the present invention. Of the screen printing method

[Explanation of symbols] 2 moving table 8 pallets 9 Thin substrate 10 Positioning pin 13 leaf spring 20 screen mask 22 Mask plate 23 pattern holes 24 squeegee 25 cream solder

Continuation of the front page (56) Reference JP-A-8-300614 (JP, A) JP-A-5-237987 (JP, A) JP-A-3-101293 (JP, A) JP-A-7-164615 (JP , A) Unexamined Japanese Patent Publication No. 4-239797 (JP, A) Actually open 1-80979 (JP, U) Actually open 58-120677 (JP, U) Actually open 57-101035 (JP, U) Actually open 4-87700 (JP, U) (58) Fields surveyed (Int.Cl. ⁷ , DB name) B41F 15/26 B41F 15/08 303 H05K 3/12 610 H05K 3/34 505

Claims (2)

(57) [Claims] 1. A movable table and a movable table provided on the movable table.
Holds the pallet on which the thin substrate is mounted and moves up and down
The holder and the moving table are sandwiched between
A first transfer container for transferring a pallet with a mold substrate attached.
A bear and a second conveyor are provided, and a hole is provided in the pallet , and the pallet is slidably inserted into the pallet to project from the upper surface of the pallet and fitted into a positioning hole provided in the thin board. a positioning pin for positioning the thin substrate Te, screen printing apparatus characterized in that a biasing means for biasing the positioning pins provided on the lower surface of the pallet upwardly. 2. A screen printing apparatus according to claim 1 is used.
That a cream solder of the screen printing method, the first of
The pallet with thin substrates is mounted on the conveyor
The process of moving it to the holder and holding it in the holder
Drive the cable to move the thin board on the pallet
The step of positioning with respect to the disk and the upper surface of the thin substrate.
Abut the disk plate and place the positioning pin
Squeeze plate pressing down process and squeegee transfer
Move the thin base through the pattern hole of the screen mask.
The process of printing cream solder on the upper surface of the board and the thin board
Positioning pin by separating from the lower surface of the mask plate
The urging means pushes up to complete the positioning holes on the thin board.
The process of fitting them all together and the pallet from the holder to the second
And a step of discharging to a downstream side by a conveyer .