JP2003291554A - Screen mask and method for cleaning the same screen mask - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a screen mask used to print a cream solder to be cleaned until the mask can endure continuous printing and to be realized at low cost. <P>SOLUTION: The screen mask 1 includes a printing region made of a pore group for a printing pattern, and comprises: cleaning liquid passing holes 2 provided out of the printing region to pass the cleaning liquid used to clean the mask after printing. The mask 1 further comprises: a wet type cleaning unit 41 disposed under the mask to supply and clean the lower surface of the mask, and a dry cleaning unit 42 disposed above the mask and having a cleaner for wiping the upper surface of the mask. In this mask, the mask is cleaned to be wiped by both the units. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen mask used for printing cream solder or the like on a substrate or the like, and a method for cleaning the screen mask.

[0002]

2. Description of the Related Art Conventionally, when soldering electronic parts on a printed circuit board or the like, cream solder is usually used, and as a device for printing / applying such cream solder to a desired pattern, generally, FIG. The printing device X as shown in FIG. 9 was used.

This has a large number of small holes 310 so that a desired pattern can be obtained, and a screen mask 200 that is positioned and mounted on the printed circuit board 100 and can be slid linearly on the screen mask 200. Squeegee 40
0 and residual solder 55 attached to the screen mask 200
And a mask cleaning device 600 that cleans and removes 0.

The mask cleaning device 600 includes a wet cleaning unit 610 that uses a mask cleaning liquid and applies ultrasonic waves to clean the lower surface of the screen mask 200, and the upper surface of the screen mask 200 is composed of a dry towel or paper. The dry cleaning unit 620 is composed of a pair of a dry cleaning unit 620 configured to be wiped with a cleaning body, and the dry cleaning unit 620 has a squeegee 4 as shown in FIG.
It is configured so that it can be moved up and down so as to be contradictory to the squeegee 400 while being linked to 00.

That is, both of them are constructed so that they can be moved up and down by a cylinder or the like, and the dry cleaning unit 620 is in the raised position when the squeegee 400 is lowered, and the dry cleaning unit 620 is in the lowered position when the squeegee 400 is raised.

When actually printing using the printing apparatus X, first, the screen mask 200 is positioned and set on the printed circuit board 100 or the like to be printed, and the cream solder 500 is supplied to the printing area 700, As shown in FIG. 9, the squeegee 400 is used as a screen mask 200.
Print by sliding linearly above.

As the screen mask 200, a metal mask made of metal which is excellent in printing accuracy and durability is usually used.

That is, as shown in FIG. 10, the screen mask 200 has a rectangular frame 220 and a mesh portion 230 made of stainless steel or a polyester material.
And a nickel alloy mask portion 240 is provided via the mesh portion 230. The mask portion 240 includes
A print pattern small hole group 300 including a large number of small holes 310 formed by etching or laser processing so as to correspond to the print pattern is provided (see FIG. 7). Figure 10
Inside, 700 includes the printing pattern small hole group 300,
It is a printing area substantially used for solder printing.

On the other hand, as semiconductor devices are becoming smaller, bumps and the like formed by solder printing are also being made finer. As shown in FIG. 8, residual solder 550 is left in the small holes 310 of the screen mask 200. If there is a residue, a print defect 800 may occur as shown in FIG.

Therefore, as described above, the wet cleaning unit 610 which applies ultrasonic vibration and cleans the lower surface of the mask using a mask cleaning liquid containing alcohol or the like.
And a dry cleaning unit 620 for wiping the upper surface of the mask with a dry towel or the like.
The screen mask 200 is cleaned every time printing is performed to remove the residual solder 550 and the like.

That is, the dry cleaning unit 610 disposed on the upper side of the mask is interlocked with the squeegee 400 as described above, and is configured to reciprocate on the upper surface of the mask together with the squeegee 400. When printing is performed, the squeegee 400 is on standby after being separated from the upper surface of the mask, and the squeegee 400 is set to the initial position (FIG.
(Indicated by the one-dot chain line in Fig. 2), the squeegee 400 moves up and the dry cleaning unit 610 descends, and the residual solder 550 is wiped off while sliding on the upper surface of the mask. 200 is washed. When the cleaning is completed, the printing is returned to the initial position and the next printing is started.

By the way, the reason why the dry cleaning unit 620 is provided on the upper surface of the mask and the wet cleaning unit 610 having a high cleaning ability is not provided as in the above-described structure is that the wet cleaning unit 62 is also provided on the upper side of the mask.
When 0 is provided, dripping of the mask cleaning liquid occurs, and if the cream solder 500 is supplied with the cleaning liquid remaining in the small holes 310 and the like, this also causes printing failure. Because it is not suitable for.

[0013]

However, in the conventional mask cleaning apparatus 600 described above, even if the mask cleaning is performed every time printing is performed, the screen mask 200 is still used.
Since the cleaning unit disposed on the upper surface side of the mask is a dry type that only wipes it off, the cleaning performance on the upper surface of the mask is inferior and residual solder 55
There were many cases such as 0 left.

As a result, a printing defect such as a printed surface is easily broken (see FIG. 11), and it is difficult to obtain a uniform printed pattern with a good finish.

It is an object of the present invention to provide a screen mask and a method for cleaning the screen mask which can solve the above problems.

[0016]

In order to solve the above problems, according to the present invention, in a screen mask provided with a print region consisting of a small hole group for a print pattern, a mask after printing is provided outside the print region. A cleaning liquid passage hole was provided for passing the cleaning liquid used for cleaning.

Further, according to the present invention as set forth in claim 2, a wet cleaning unit for supplying a cleaning liquid to the lower surface of the screen mask for cleaning is arranged below the screen mask, and a cleaning surface for cleaning the upper surface of the mask is cleaned above the screen mask. In a method of cleaning a screen mask, in which a dry cleaning unit having a wiping body is arranged and the screen mask is wiped and cleaned by both units, the screen mask has a portion outside a printing area including a group of small holes for a printing pattern. A cleaning liquid passage hole was previously provided at one position, and a part of the cleaning liquid of the wet cleaning unit was infiltrated into the wiping body of the dry cleaning unit through the cleaning liquid passage hole.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a screen mask provided with a printing region consisting of a group of small holes for a printing pattern, and a washing liquid passing through the outside of the printing region to pass a washing liquid used for washing the mask after printing It is provided with holes.

In the present invention, when cleaning the screen mask, the purpose is to further enhance the cleaning power. To this end, it is not necessary to improve the cleaning device or introduce a new device. Instead, the screen mask itself is subjected to simple processing to greatly improve the removal rate of residual solder.

That is, the solder mask screen mask is provided with a printing area consisting of a group of small holes for the printing pattern, and a cleaning liquid passage hole of a desired size is provided outside the printing area. , Dry cleaning in which a plurality of mask cleaning liquids are provided above the screen mask from a wet cleaning unit disposed below the screen mask through each cleaning liquid passage hole so as to cross the printing area The dry cleaning unit is used as a semi-wet type so that it can be soaked in a cleaning body such as a towel of the unit.

In the method of cleaning the screen mask having the above-mentioned structure, the cleaning device used is not different from the conventional one, and a wet cleaning unit for supplying a cleaning liquid to the lower surface of the screen mask for cleaning is arranged below the screen mask. In addition, a dry cleaning unit having a wiping body for wiping the upper surface of the mask is arranged above the screen mask, and both units clean and wipe the screen mask.

Then, the configuration of the screen mask is
As described above, since the cleaning liquid passage hole is provided in advance at the outer position of the printing area including the small hole group for the printing pattern, a part of the cleaning liquid of the wet cleaning unit is transferred through the cleaning liquid passage hole. Can be infiltrated into the wiper of the dry cleaning unit, and the mask cleaning liquid that was originally used for the lower surface of the mask can be used for the upper surface of the mask. It is possible to always maintain a clean state in which no occurrence occurs. Therefore, even if continuous printing is performed, the finish of the printing surface is beautiful, and printing defects such as deformation of the printing surface can be reduced as much as possible.

Moreover, by appropriately changing the shape and size of the cleaning liquid passage hole and the number thereof, the amount of the mask cleaning liquid supplied to the dry cleaning unit above the mask can be easily controlled and supplied to the upper surface of the mask. By controlling according to the amount of cream solder to be used, the type of the same solder, or the tendency of solder residue due to the printing pattern, a clean screen mask can be maintained at any time, and continuous printing with minimal printing defects is possible. The yield is also greatly improved.

As described above, in the present embodiment, the mask cleaning ability can be greatly improved even though the structure is extremely simple.

Hereinafter, embodiments of the present invention will be described more specifically with reference to the accompanying drawings.

FIG. 1 is an explanatory view of the screen mask according to the present embodiment, FIG. 2 is an end view of the screen mask, and FIG.
Is a schematic explanatory view of the mask cleaning device, FIGS. 4 and 5 are functional explanatory views when cleaning the screen mask according to the present embodiment, and FIG. 6 is an explanatory view of a cross section of a printing surface.

As shown in FIGS. 1 and 2, the screen mask 1 according to the present embodiment has basically the same structure as the conventional screen mask 200 described with reference to FIG.

That is, a stainless steel mesh portion 12 is stretched over a rectangular frame 10, a nickel alloy mask portion 13 is provided through the mesh portion 12, and a printing pattern is formed on the mask portion 13. A printing pattern small hole group 15 composed of a large number of small holes 14 formed by etching or laser processing is provided corresponding to the above, and a printing region including the printing pattern small hole group 15 is substantially used for printing. A metal mask having 16 is used.

A feature of the above construction is that a cleaning liquid passage hole 2 is provided outside the printing region 16 for passing a cleaning liquid used for cleaning the mask after printing.

In the present embodiment, a plurality of cleaning liquid passage holes 2 each having a predetermined size are provided outside the printing area 16 so that the length thereof is longer than the side of the printing area 16. The mask portions 13 are arranged linearly so as to cross the mask portion 13. That is, the cleaning liquid passage holes 2 are linearly arranged in a direction orthogonal to the moving direction of the squeegee 3 used for printing.

In the present embodiment, the cleaning liquid passage holes 2 formed in a small oval shape are arranged in a zigzag pattern in the longitudinal direction. In other words, the plurality of cleaning liquid passage holes 2 are arranged at predetermined intervals in the longitudinal direction. Lined cleaning liquid passage 2
0, and the cleaning liquid passage portions 20 are provided in two rows, and each cleaning liquid passage hole 2 is located between two adjacent cleaning liquid passage holes 2 of the adjacent cleaning liquid passage portion 20. There is. The cleaning liquid passage hole 2 can be easily formed by laser processing or etching, like the small hole 14 for printing.

The screen mask 1 having the above structure is
Each time the solder printing is executed, the cleaning process is performed so that the solder printing can be continuously performed.

The cleaning device 4 for performing the mask cleaning process is shown in FIG.
As shown in FIG. 5, this also has the same configuration as that described in the conventional technique.

That is, the cleaning device 4 is incorporated in the solder printing device 5, and the wet cleaning unit 41 for cleaning the lower surface of the mask using the mask cleaning liquid while applying ultrasonic vibration.
And a cleaning body 4 such as a dry towel connected to the squeegee 3.
3 and a dry cleaning unit 42 for wiping the upper surface of the mask. The cleaning body 4 of the dry cleaning unit 42
3 is sent out from the sending roller 44 and taken up by the take-up roller 45.
1 includes an ultrasonic wave generator 47, which peels off residual solder and the like in the small holes 14 by ultrasonic vibration, and
The cleaning cloth 46 soaked with the mask cleaning liquid is also sent from the sending roller 44 to wash the lower surface of the mask and then wound by the take-up roller 45. In the figure,
Reference numeral 48 is a unit lifting cylinder, 31 is a cream solder supply pipe having an opening arranged near the tip of the squeegee 3, and 32 is a squeegee lifting cylinder.

By printing with the solder printing device 5 having the above-mentioned configuration, the screen cleaning device 4 attached thereto cleans the screen mask 1 every time printing is performed, and each small mask on the screen mask 1 and in the printing region 16 is cleaned. Although the residual solder and the like in the holes 14 are removed, in the present embodiment, since the cleaning liquid passage hole 2 is formed in the screen mask 1, the cleaning effect is significantly improved.

That is, as shown in FIGS. 4 and 5, when the mask cleaning process is started, the dry cleaning unit 42 above the screen mask 1 is lowered and
Wet cleaning unit 41 under the screen mask 1
Rise to bring the screen mask 1 into a sandwiched state.

At this time, the mask cleaning liquid impregnated in the wiping cloth 46 of the wet cleaning unit 41 exudes to the upper surface of the screen mask 1 through the cleaning liquid passage hole 2 (FIG. 5).
(Refer to arrow F), and further into the wiping body 43 of the dry cleaning unit 42. Then, the wiping body 43 slides in a state where a desired amount of the mask cleaning liquid is soaked, the lower surface of the mask can be cleaned with a sufficient amount of the conventional cleaning liquid, and the upper surface of the mask does not drip. It becomes possible to clean with a small amount of mask cleaning liquid, and a sufficient cleaning effect can be produced.

Further, as described above, each cleaning liquid passage hole 2
Is located between two adjacent cleaning liquid passage holes 2 of the adjacent cleaning liquid passage portion 20, so that the wiping body 43 of the dry cleaning unit 42 exerts a semi-wet function at least for the entire printing region 16. The upper surface of the mask can be effectively cleaned.

Therefore, the dry cleaning unit 42, which has only wiped the upper surface of the screen mask 1 with the dry wiper 43, becomes a semi-wet state containing an appropriate amount of the mask cleaning liquid, and the upper surface of the screen mask 1 and the printing area. The cleaning effect in each small hole 14 in 16 is remarkably enhanced, and the cleaning ability of the cleaning device 4 is significantly improved. The amount of the mask cleaning liquid that permeates the wiping body 43 can be controlled by the size and shape of the cleaning liquid passage hole 2.

As described above, in the present embodiment, the cleaning liquid passage hole 2 is formed in the screen mask 1 without newly introducing a printing device or a cleaning device, and the mask 1 has a simple structure. It is possible to enhance the cleaning effect of and to effectively remove residual solder and the like.

When solder printing is performed using such a screen mask 1, even if continuous printing is performed, effective mask cleaning is performed every time printing is performed. Therefore, as shown in FIG. The solder-printed surface 7 printed on the object has a good beautiful finish without losing its shape.

Therefore, for example, when manufacturing a semiconductor device requiring solder printing, it is possible to significantly reduce the occurrence of printing defects in the solder printing process and improve the product yield.

By the way, in the present embodiment, the cleaning liquid passage hole 2 has been described as an elliptic shape and arranged in two rows, but the shape and size of the cleaning liquid passage hole 2 are appropriately determined. be able to.

For example, as shown in FIG. 7, the cleaning liquid passage hole 2 has an elliptical shape, but the cleaning liquid passage holes 2 are vertically arranged in three stages and alternately arranged in two stages. It may be configured. In addition, the best cleaning effect can be achieved by appropriately changing it according to the print pattern, the properties of the cream solder, and the like.

[0045]

The present invention is carried out in the form as described above, and has the following effects.

(1) According to the present invention as set forth in claim 1, in a screen mask provided with a print region consisting of a group of small holes for a print pattern, the screen mask is used outside the print region for cleaning the mask after printing. By providing the cleaning liquid passage hole for passing the cleaning liquid, when cleaning the screen mask, a part of the cleaning liquid is transmitted to the upper surface of the mask through the cleaning liquid passage hole,
The cleaning ability is greatly improved to prevent the generation of residual solder, etc. In addition, since the cleaning liquid does not drip, continuous printing is possible, and printing defects due to the deformation of the printing surface etc. are prevented as much as possible. Therefore, the product yield can be improved.

(2) According to the second aspect of the present invention, a wet cleaning unit for supplying a cleaning liquid to the lower surface of the screen mask for cleaning is arranged below the screen mask, and the upper surface of the screen mask is wiped above. In a method of cleaning a screen mask, in which a dry cleaning unit including a wiping body is arranged and the screen mask is wiped and cleaned by both units, the screen mask includes a printing area of a small hole group for a printing pattern. By previously providing a cleaning liquid passage hole at the outer position, and allowing a part of the cleaning liquid of the wet cleaning unit to infiltrate into the wiping body of the dry cleaning unit through the cleaning liquid passage hole, the cleaning liquid passage hole is formed. A part of the cleaning liquid of the wet cleaning unit can be soaked in the wiping body of the dry cleaning unit through The mask cleaning liquid originally used for the lower surface of the mask can be diverted to the upper surface of the mask to greatly improve the cleaning performance also for the upper surface of the mask and prevent the generation of residual solder, and the cleaning liquid does not drip. Therefore, continuous printing is possible, and furthermore, it is possible to prevent the occurrence of printing defects due to the deformation of the printing surface, etc., and it is possible to improve the product yield.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a screen mask according to this embodiment.

FIG. 2 is an end view of the screen mask.

FIG. 3 is a schematic explanatory view of a mask cleaning device.

FIG. 4 is a functional explanatory diagram at the time of cleaning the screen mask according to the present embodiment.

FIG. 5 is a functional explanatory diagram at the time of cleaning the screen mask according to the present embodiment.

FIG. 6 is an explanatory diagram of a printing surface.

FIG. 7 is an explanatory diagram showing an example of a cleaning liquid passage hole.

FIG. 8 is an explanatory diagram of a conventional printing apparatus.

FIG. 9 is an explanatory diagram of a conventional printing apparatus.

FIG. 10 is an explanatory diagram of a conventional screen mask.

FIG. 11 is an explanatory diagram of a printing surface printed with a conventional screen mask.

[Explanation of symbols]

1 screen mask 2 Cleaning liquid passage hole 3 squeegee 4 cleaning equipment 5 Solder printer 14 small holes 16 print area 41 Wet cleaning unit 42 Dry cleaning unit 43 Cleaning body

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) B41F 35/00 B41F 35/00 D 5E343 H05K 3/34 505 H05K 3/34 505D // H05K 3/26 3/26 A F term (reference) 2C250 FA06 FB01 FB12 FB23 2H114 AB15 AB17 DA25 EA04 GA27 GA31 3B116 AA02 AA47 AB53 BA08 BA35 3B201 AA02 AA47 AB53 BA08 BA35 BB57 BB95 5E319 AA03 CC22 CD01 GG20 5E343 BB13 DDFF23BB34 DD13FF34BB34 DD13BB34 BB33 DD13EE

Claims (2)

[Claims] 1. A screen mask provided with a printing region consisting of a group of small holes for a printing pattern, wherein a cleaning liquid passage hole for passing a cleaning liquid used for cleaning the mask after printing is provided outside the printing region. Characteristic screen mask. 2. A wet cleaning unit for supplying a cleaning liquid to the lower surface of the screen mask for cleaning is disposed below the screen mask, and a dry cleaning unit having a cleaning body for cleaning the upper surface of the mask is disposed above the screen mask. In the method for cleaning a screen mask, the cleaning liquid passing holes are arranged in advance in an outer position of a printing area composed of a group of small holes for a printing pattern, the cleaning liquid passing holes being provided by wiping and cleaning the screen mask with both units. A method for cleaning a screen mask, characterized in that a part of the cleaning liquid of the wet cleaning unit is allowed to infiltrate into the wiping body of the dry cleaning unit through the cleaning liquid passage hole.