JPH09216339A - Cream solder coating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cream solder coating apparatus not generating printing irregularity in forward and return passages of continuous printing. SOLUTION: A squeegee 1 is constituted so as to be capable of being moved up and down and rotated by 180 deg.. When cream solder 11 is applied to a first printed wiring board through a screen mask 9, the coating of cream solder is performed by sweeping the printed wiring board from the left end thereof to the right by the squeegee (a), (b). When the coating of the first printed wiring board with cream solder is completed, the squeegee 1 is raised upwardly to be rotated by 180 deg. and the printed wiring board is discharged (c), (d). A second printed wiring board 10' is set (e) and the squeegee 1 is lowered on the screen mask 9. Subsequently, the squeegee 1 is swept to the left (f). As a result, the same surface of the squeegee always comes into contact with cream solder with respect to the reciprocal moving direction of the squeegee and irregularity is eliminated in printing conditions.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cream solder applicator, and more particularly to a screen such as a metal mask screen arranged on a printed circuit board, supplying cream solder to the screen and moving a squeegee on the screen. The present invention relates to a cream solder applying apparatus adapted to apply cream solder to a predetermined position of a printed circuit board.

[0002]

2. Description of the Related Art Conventionally, as one of connection material supply devices for mounting surface mount components of this type, there is one as shown in FIG. As shown in FIG. 3A, a screen mask 32 made of stainless steel, nickel or the like is placed on a printed wiring board 31 made of phenol resin, glass epoxy resin or the like. The screen mask 32 is provided with an opening having a size corresponding to a predetermined pad of the printed wiring board 1 at a position corresponding to the pad. The cream solder 34 is placed on the end of the screen mask 32, and above the screen mask 32,
Imprint the cream solder 34 on the printed wiring board 31 through the opening of the screen mask 32 while applying pressure 2
Book squeegees 35a and 35b are provided so as to face each other. The cream solder 34 is made by kneading particles of solder as a connecting material with a rosin resin and an activator.

Next, the operation of the supply device having the above structure will be described. First, the screen mask 32 is superposed on the printed wiring board 31 so that the pads of the printed wiring board 31 and the openings of the screen mask 32 opened corresponding to the pads match each other. Next, the squeegee 35a on the left side is lowered onto the screen mask 32 as shown in FIG. 3 (a), and a constant speed is applied to the right side as shown in FIG. 3 (b) while applying pressure. And the cream solder 34 is kneaded through the opening of the screen mask 32 and pushed into the opening of the screen mask 32. The squeegee 35 a is stopped after passing through the opening of the screen mask 32 at the right end, and is pulled up from the screen mask 32. Finally, the printed wiring board 31 and the screen mask 32 are separated from each other vertically, so that the cream solder 34 is removed from the screen mask 32 to the printed wiring board 3.
1 is transferred to complete printing of the first sheet.

Next, the printing operation of the second printed wiring board 31 'shown in FIG. At this time, since the cream solder 34 is on the right side of the screen mask 32,
The squeegee 35b is lowered onto the screen mask 32,
As shown in (d) of the figure, printing is performed by sweeping to the left. Similarly, the left squeegee 35a is used for printing the odd number of sheets, and the right squeegee 35 is used for printing the even number of sheets.
The printing operation is continuously performed using b.

However, the above printing method has the following problems. That is, since two squeegees are used, conditions such as printing pressure, angle, and pushing amount must be adjusted separately for each squeegee.
When the setup is changed, that is, when the screen mask is changed to a new one and the printing is started by adjusting the conditions to different kinds of printed wiring boards, the setup change time becomes long and the difference in each adjustment state causes an odd number. There is a problem in that the printing state differs between the first substrate and the even substrate, and the quality varies.

In order to deal with such a problem, a function of jumping a paste onto a squeegee is provided as disclosed in, for example, Japanese Patent Laid-Open No. 62-57664.
An apparatus for performing continuous printing with a squeegee of a book has been proposed.
This device will be described with reference to FIG. This device is different in structure from the device of FIG. 7 because it has one squeegee 35. Note that other reference numerals indicate the same or equivalent parts as in FIG. 7.

Printing on the first printed wiring board 31
As shown in FIGS. 3A and 3B, the squeegee 35 is lowered onto the screen mask 32 and swept rightward. The printing of the first sheet is the same as in the case of FIG. When printing on the second printed wiring board 31 ', the squeegee 35 is temporarily turned on after the printing of the first printed wiring board is finished, as shown in FIG. Pulled up, then moved horizontally to the right, screen mask 3
The second opening is lowered to the right of the solder paste 34. And this time, sweep to the left side and the second wiring board 3
Print on 1 '. Thereafter, similarly, after each printing, the squeegee 35 rides over the cream solder 34 and then performs the next printing.

[0008]

However, the printing method using the printing apparatus as described above has the following problems.

(1) When performing repeated printing, since the odd-numbered sheet and the even-numbered sheet have different surfaces in contact with the cream solder of the squeegee, the printing conditions differ between the odd-numbered sheet and the even-numbered sheet. There is. This is because the tip of the squeegee is worn and deformed due to continuous printing, but the extent of the abrasion is different between the two surfaces.

(2) When printing continuously, there is a problem that it is difficult to adjust the angle of the squeegee. For example, the angle of the squeegee with respect to the screen mask is 70 with respect to the traveling direction.
If you print on the forward path at °, the direction of travel will be reversed on the return path.
Printing is performed at 10 °, and printing is performed at an angle different from the forward path. Alternatively, if it is attempted to print at the same angle as the outward path, it is necessary to readjust the angle before printing. Also, if the angle of the squeegee with respect to the screen mask is 90 °, there is no problem because the same angle will be used for reciprocating without any adjustment, but usually the viscosity characteristics of cream solder, the size of the opening of the screen mask, the pitch, etc. It is necessary to adjust the angle of the squeegee to control the force for printing the cream solder or the force for rolling the squeegee, and the angle of the squeegee with respect to the screen mask is not always 90 °.

(3) Since the squeegee is pressed against the screen mask to move, warpage occurs in the moving process,
In the above-mentioned method, since the direction in which the squeegee warps differs between the forward pass and the backward pass during continuous printing, there is a problem that the squeegee deteriorates faster and the life is shortened.

(4) When the squeegee is separated from the screen mask, the cream solder usually adheres to the squeegee to some extent. It will be dragged backwards against. For this reason, there is a problem that the cream solder attached to the rear side after printing connects the openings of the screen mask to cause printing failure.

An object of the present invention is to eliminate the above-mentioned problems of the prior art, and to provide a cream solder coating apparatus which does not cause variations in printing during the forward and backward passes of continuous printing.

[0014]

In order to achieve the object of the invention described above, the invention of claim 1 is a cream solder which is applied to a printed wiring board through a screen mask by sweeping the cream solder with a squeegee. The coating device is characterized in that the same surface of the squeegee is always in contact with the cream solder with respect to the reciprocating direction of the squeegee.
Further, the invention of claim 2 comprises means for moving the squeegee up and down, means for rotating the squeegee by 180 °, and means for horizontally moving the squeegee, and the squeegee is rotated by 180 ° after each application. The feature is that it is rotated. The invention according to claim 3 further comprises means for moving the squeegee up and down, means for horizontally moving the squeegee, and a clamp for fixing the screen mask, the printed wiring board, and the printing table in an aligned state.
The screen mask fixed by the clamp,
The printed wiring board and the printing table are integrally rotated by 180 °, and the screen mask, the printed wiring board, and the printing table are fixed and rotated by 180 ° before and after the application of the even-numbered printed wiring board. Another feature is that the squeegee is moved horizontally to the outside of the cream solder while the squeegee is raised.

According to the invention of claims 1 to 3, since the same surface of the squeegee always comes into contact with the cream solder when the squeegee reciprocates, the squeegee can always be printed under the same printing conditions. As a result, high quality printing can be performed. Further, as compared with the conventional device that uses both sides for the reciprocating movement of the squeegee, since the squeegee always bends in one direction, the life of the squeegee is less deteriorated and the squeegee moves in the moving direction of the squeegee. It is also possible to eliminate the problem that solder is attached to the rear side and the printed surface becomes dirty.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram showing a configuration of a squeegee device of a cream solder coating device according to an embodiment of the present invention. The squeegee device includes a squeegee 1, a squeegee holder 2 for holding the squeegee 1, a squeegee angle fixing screw 3 for adjusting the angle of the squeegee 2, a rotary stepping motor 4 for rotating the squeegee 180 °, and a vertical direction for vertically moving the squeegee. A moving actuator 5, a rod 6 for transmitting the power of the actuator 5 to a squeegee, and a horizontal moving actuator 7 for horizontally moving the squeegee.
And a guide rod 8 for guiding the actuator 7. 9 is a screen mask.

Next, the operation of this embodiment will be described with reference to FIGS. 2A to 2F are views showing the progress of the operation of the present embodiment, 10 is a printed wiring board, 11 is a cream solder, and other reference numerals are the same as or equivalent to those in FIG. First, the squeegee 1 is moved down onto the screen mask 9 by the vertical movement actuator 5 as shown in FIG. 2 (a). Next, the squeegee 1 is moved to the right by the horizontal movement actuator 7, so that the cream solder 11 is applied to a predetermined position of the printed wiring board 10 through the screen mask 9.
As shown in FIG. 2B, the first printed wiring board 1
When the application to 0 is completed, the squeegee 1 is pulled up by the vertical movement actuator 5 as shown in FIG. Subsequently, as shown in FIG. 3D, the rotary stepping motor 4 rotates 180 °. This time,
When the tip of the squeegee 1 does not come to the outside of the cream solder 11, the horizontal movement actuator 7 moves the tip of the squeegee 1 to the outside of the cream solder 11 at least. In this state, the second printed wiring board is set by a board supply device (not shown). Then, as shown in FIG. 6 (e), the squeegee 1 is lowered by the actuator 5 for moving in the vertical direction.

Printing on the second printed wiring board 10
As shown in FIG. 1F, the squeegee 1 is moved leftward by the horizontal movement actuator 7 to apply the cream solder 11 to a predetermined position on the printed wiring board 10.

According to the cream solder applicator of the present embodiment, the squeegee 1 rotates 180 ° after each printing operation, and the same surface of the squeegee contacts the cream solder 11 with respect to the moving direction. There is no variation in the even-numbered sheets and the odd-numbered sheets due to wear deformation. In addition, since the squeegee always bends in the same direction, the squeegee will not be repeatedly folded back and its life will not deteriorate, and since there is always one squeegee surface in contact with the cream solder, the paste will stick to the rear side in the moving direction. There is nothing to do. Further, by rotating the squeegee by 180 °, even if the squeegee has an angle from the vertical direction, the same angle is reproduced in the reciprocating direction, so that the squeegee can be easily angled.

Next, a second embodiment of the present invention will be described with reference to FIG. This embodiment uses a squeegee 180
° It is designed to rotate the printing table instead of rotating it. The printing table is a printed wiring board 21.
Table 22 for holding and fixing
2, a mask fixing clamp 24 for fixing the screen mask 23 and the printed wiring board 21, and a rotary stepping motor 25 for rotating the whole by 180 ° with these fixed.
After the application, the screen mask 23 and the printed wiring board 21
It is composed of an elevating motor 26 that raises and lowers the printing table to separate the and, and a screw 27.

Next, the operation of this embodiment will be described with reference to FIG.
~ It demonstrates with reference to FIG. In these figures, 1 is a squeegee, 11 is a cream solder, and other symbols are those shown in FIG.
Indicates the same as or equivalent to. When applying the cream solder 11 to the first printed wiring board 21, the squeegee 1 sweeps the cream solder 11 placed on the screen mask 23 leftward as shown in FIG. 4 (a). . Same figure
At (b), the sweep is completed, and the mask fixing clamp 24 is released as shown in FIG.
The drive of 6 drives the print table 22 downward. Then, the first printed wiring board 21 to which the cream solder is applied is discharged.

Next, as shown in FIG.
The first printed wiring board 21 ′ is placed on the printing table 22. After this, the printed wiring board 21 'is attached to the screen mask 2
3, the rotation of the lifting motor 26 is transmitted to the lifting screw 27, the printing table 22 rises, and the printed wiring board 21 ', the screen mask 23, and the printing table 22 come into close contact with each other to complete the alignment. Then, the mask fixing clamp 24 is closed to fix them. Next, as shown in FIG. 6 (e), the rotary stepping motor 25 keeps all 18
While rotating 0 °, the squeegee 1 also moves horizontally at the same time and moves to the right side as shown in FIG. As a result, it is possible to apply the coating operation by contacting the same surface with the cream solder 11 in the moving direction of the squeegee 1 even after the second sheet.

In FIG. 6 (g), the squeegee 1 is lowered onto the screen mask 23 and swept to the left. As a result, the cream solder 11 is applied onto the printed wiring board 21 '. When this sweeping is completed, the result is as shown in FIG. 6 (h), and the printed wiring board 21 'is set so that no trouble occurs in the next process.
Is rotated 180 ° again, and the orientation is returned to the original position as shown in FIG. Then, the mask fixing clamp 24 is released, and the elevating motor 26 is driven to drive the printing table 22 downward. Then, the second printed wiring board 21 'to which the cream solder is applied is discharged to the next step.

After that, the odd-numbered printed wiring boards perform the same operation as the first sheet, and the even-numbered printed wiring boards perform the same operation as the second sheet. By this operation, even if continuous printing is performed,
Since the same surface is always in contact with the cream solder with respect to the moving direction of the squeegee and the coating operation can be performed, the same effect as that of the first embodiment can be obtained.

[0025]

As is clear from the above description, according to the inventions of claims 1 to 3, the following effects can be expected.

(1) Since the same surface of the squeegee is always in contact with the cream solder in the reciprocating direction of the squeegee, there is no variation in printing conditions. Therefore, high quality cream solder application can be realized. Further, since the cream solder does not adhere to the rear of the squeegee in the moving direction, the printed surface is not stained by the cream solder dragged by the squeegee.

(2) Since the squeegee always bends in one direction, the life of the squeegee can be extended as compared with the conventional example in which the squeegee bends in both directions.

(3) Since the squeegee is rotated by 180 ° every time printing is completed so that the same surface of the squeegee contacts the moving direction, even if the squeegee has an acute angle with respect to the vertical direction. , The squeegee can be easily reciprocated at the same acute angle.

(4) Since the squeegee can be rotated by 180 ° during maintenance and condition adjustment, the surface easy to work can be turned to the operator, and highly accurate maintenance and adjustment can be performed in a short time. Will be able to.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a main part of a first embodiment of the present invention.

FIG. 2 is an operation explanatory diagram of the first embodiment.

FIG. 3 is a diagram showing a configuration of a main part of a second embodiment of the present invention.

FIG. 4 is an operation explanatory diagram of the second embodiment.

FIG. 5 is an operation explanatory diagram of the second embodiment.

FIG. 6 is an operation explanatory diagram of the second embodiment.

FIG. 7 is an operation explanatory diagram of the first conventional method.

FIG. 8 is an operation explanatory diagram of a second conventional method.

[Explanation of symbols]

1 ... Squeegee, 2 ... Squeegee holder, 3 ... Squeegee angle fixing screw, 4 ... Rotation stepping motor, 5 ... Vertical movement actuator, 6 ... Rod, 7 ... Horizontal movement actuator, 8 ... Guide rod, 9 ... Screen Mask, 10 ... Printed wiring board, 11 ... Cream solder, 21 ...
Printed wiring board, 22 ... Printing table, 23 ... Screen mask, 24 ... Mask fixing clamp, 25 ... Rotating stepping motor, 26 ... Lifting motor, 27 ... Screw.

Claims (3)

[Claims] 1. A cream solder applicator for sweeping cream solder with a squeegee and applying the cream solder onto a printed wiring board through a screen mask, wherein the same surface of the squeegee is always applied to the reciprocating direction of the squeegee. A cream solder applicator characterized by being in contact with solder. 2. A cream solder applicator for sweeping cream solder with a squeegee and applying it onto a printed wiring board through a screen mask, and means for moving the squeegee up and down, and means for rotating the squeegee 180 °. A means for horizontally moving the squeegee is provided, and the squeegee is rotated by 180 ° after each application so that the same surface is always in contact with the cream solder with respect to the moving direction of the squeegee. Cream solder coating device. 3. A cream solder applicator for sweeping cream solder with a squeegee and applying the cream solder onto a printed wiring board via a screen mask, and means for moving the squeegee up and down, and means for horizontally moving the squeegee, A clamp for fixing the screen mask, the printed wiring board, and the printing table in alignment with each other; and the screen mask fixed by the clamp,
The printed wiring board and the printing table are integrally rotated by 180 °, and the screen mask, the printed wiring board, and the printing table are fixed by 180 before and after the application of the even-numbered printed wiring board.
The rotation of the squeegee and the horizontal movement of the squeegee to the outside of the cream solder while raising the squeegee ensure that the same surface of the squeegee always contacts the cream solder in the moving direction of the squeegee. Applicator for cream solder.