JPH04201261A - Mask cleaning apparatus - Google Patents

Abstract

PURPOSE:To certainly remove solder paste bonded to the rear of a mask by constituting a cleaning squeezee for pressing waste to the rear of the mask of an elastomer and providing a structure supporting the cleaning squeezee in a freely shakable manner. CONSTITUTION:The cleaning squeezee 4 supported on a cleaning squeezee support part 5 is raised by a contact and separation mechanism 6 and presses the rear of the waste positioned between a pair of guide rolls 25a, 25b to press the waste to the rear of the mask 1. In this case, the cleaning squeezee 4 is supported on the cleaning squeezee support part 5 in a freely shakable manner and constituted of an elastomer whose leading end is formed into a sharp edge shape and the waste 2 is uniformly brought into close contact with the rear of the mask 1 over the entire length of the cleaning squeezee 4. Subsequently, the whole of a cleaning apparatus is laterally moved by a moving mechanism 7 to remove the solder paste bonded to the rear of the mask 1.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a mask cleaning device, and in particular to a mask cleaning device suitable for cleaning a mask of a paste printing machine that prints solder paste using a mask. Regarding equipment.

(Prior Art) As various electronic components such as semiconductor integrated circuits have become finer, the mounting of electronic components on printed wiring boards has also become finer. Especially QFP'IC (Quad Flat
ePackage Iniegral C1rcui
Regarding t), there is a trend toward increasing the pin pitch to 0.5+a+e or less.

Conventionally, electronic components are mounted on printed wiring boards by printing a predetermined pattern of solder paste on the printed wiring board, aligning the electronic components on the printed solder paste, and then applying the solder paste. There is a method of melting and soldering electronic components. Printing of the solder paste is generally performed by a screen printing method in which the solder paste is squeezed using a metal mask in which openings in a predetermined pattern are formed.

However, when printing solder paste using a mask as described above, the solder paste adheres to the back of the mask.
During subsequent printing, the solder paste may adhere to areas other than the predetermined portions of the printed wiring board. If the solder paste adheres to areas other than the predetermined portions of the printed wiring board, the finer the pattern of the solder paste to be printed becomes, the more likely it will cause solder pre-sold shorting defects. Therefore, in order to print fine patterns of solder paste, it is essential to remove the solder paste that has adhered to the back surface of the mask.

Conventionally, solder paste printing machines equipped with a cleaning device for removing solder paste adhering to the back surface of the mask, or solder paste printing machines that can be attached as an option, are commercially available. The cleaning device is configured to remove solder paste by bringing a roll into contact with the back surface of the mask. However, since these cleaning devices do not uniformly contact the roll with the back surface of the mask, they cannot sufficiently remove the solder paste attached to the back surface of the mask, and the desired effect cannot be obtained.

(Problem to be Solved by the Invention) As described above, as a method of printing solder paste on a printed wiring board, a screen is printed by squeezing the solder paste using a mask in which a predetermined pattern of openings is formed. There is a printing method. However, when printing solder paste using this method, the solder paste adheres to the back of the mask, and when the next solder paste is printed, the solder paste adheres to areas other than the designated areas of the printed wiring board. There is a problem in that the finer the printed solder paste pattern becomes, the more likely it is to cause bridge short defects.

In order to prevent this defect from occurring, solder paste printers that are equipped with a cleaning device to remove the solder paste that adheres to the back of the mask, or solder paste printers that can be installed as an option, are commercially available. . The cleaning device is configured to remove solder paste by bringing a roll into contact with the back of the mask, but because the roll does not come into uniform contact with the back of the mask, the solder paste adhering to the back of the mask is removed. There is a problem in that it cannot be removed sufficiently and the desired effect cannot be obtained.

This invention has been made in view of the above problems,
An object of the present invention is to configure a mask cleaning device that automatically and reliably removes solder paste adhering to the back surface of a mask.

[Structure of the Invention] (Means for Solving the Problems) In a mask cleaning device for removing solder paste attached to the back side of a mask used for printing solder paste, the mask cleaning device is connected to a supply device that supports a rag supply reel. A reel support part, a take-up reel support part that supports the waste material take-up reel, a drive device that rotates the take-up reel, and a tensioning device that applies tension to the waste material stretched from the waste supply reel to the take-up reel. a cleaning squeegee made of an elastic body that presses the rag against the back of the mask by pressing the back of the rag stretched from the rag supply reel to the take-up reel; a cleaning squeegee supporting section that supports the cleaning squeegee in a movable manner; a moving mechanism that moves the cleaning squeegee together with the cleaning squeegee supporting section toward and away from the back surface of the rag; In addition to the mechanism, the cleaning squeegee is configured to include a moving mechanism that moves on a plane perpendicular to the moving direction of the cleaning squeegee by the above-mentioned approach and separation mechanism.

(Function) As described above, if the cleaning squeegee for pressing the rag against the back of the mask is made of an elastic material and the cleaning squeegee is supported in a swingable manner, the cleaning squeegee presses the rag against the back of the mask. can be brought into uniform contact with the back surface of the Therefore, by pressing the cleaning squeegee against the back of the rag using the contact/separation mechanism, and moving the cleaning squeegee using the moving mechanism on a plane perpendicular to the direction in which the cleaning squeegee is moved by the contact/separation mechanism, the cleaning squeegee adheres to the back of the mask. Solder paste can be removed reliably.

(Example) Hereinafter, the present invention will be described based on an example with reference to the drawings.

FIG. 1 shows the overall structure of a metal mask cleaning device used for printing solder paste, which is an embodiment of the present invention, and FIG. 2 shows the structure of its main parts. This cleaning device uses a metal mask (
A waste path line mechanism (1) that moves a waste cloth (2) to clean solder paste attached to the back side
3), a cleaning squeegee (4) that presses the back of the rag (2), and this cleaning squeegee (4)
The cleaning squeegee support part (5
), an approach mechanism (6) for moving the cleaning squeegee (4) towards and away from the back surface of the rag (2), and a plane perpendicular to the direction of movement of the cleaning squeegee (4) by this approach/separation mechanism (6). The main component is a moving mechanism (7) that moves the.

The moving mechanism <7) is the base plate of the printing press body ([0)
An X table (I3) that moves in the X-axis direction by the drive of a drive device (12) along a guide rail <11) installed above, and a base plate <14 of this X table (13).
) and an X table (17) that moves in the Y-axis direction by a drive device (16) along a guide rail (15) installed on the top.

The wespass line mechanism (3) is connected to the X table (17).
) has a pair of support plates (20a) and (20b) attached to both ends of the base plate (19), and this end plate (
20a).

A supply reel support part (22
) and a rag take-up reel (23) rotatably arranged between the end plates (20a) and the lower part of the other side of (20b).
a take-up reel support part (24) that supports these, a supply reel support part (22) and a take-up reel support part (24)
) Cleaning squeegee (4) located on the center between
A pair of guide rolls (25a) rotatably supported by end plates (20a) and (20b) sandwiching and close to each other.
, (25b), and an end plate (20a) between the supply reel support section (22) and one guide roll (25a), and between the take-up reel support section (24) and the other guide roll (25b). ).

(20b) Each pair of tension rolls (26a), (2fib) and (27a) are rotatably supported between them.

(27b) and the end plate (20
a) A pair of drive rolls (28a) rotatably supported between (2Qb).

(28b), this drive roll (28a), (28
a kite roll (29) rotatably supported between the take-up reel support part (24) and the take-up reel support part (24), and the drive rolls (28a) and (28b).
) and a drive device (30) whose drive source is a pulse motor (not shown) that rotationally drives the motor. In addition, each pair of tension rolls (26a), (26b), (2
7a), (27b) and drive roll (28a)
, (28b) one roll (26b) , (27
b) and (28b) are respectively the other roll (26
a) , (27a) , and (28a) can be moved toward and away from them.

Therefore, the rag (2) of the rag supply reel (21) supported by the supply reel support part (22) is sequentially transferred to the tension rolls (2Ba), (26b), and the pair of rolls (
25a), (25b), tension roll (27a)
, (27b), drive roll (28a), (28b
) and the guide roll (29), the rag take-up reel (23) supported by the take-up reel support (24)
), and is wound onto the waste take-up reel (23) to a predetermined length by driving the drive device (30) that rotates the take-up reel support part (24) and drive rolls (28a) and (28b). It is now possible to take it.

The cleaning squeegee (4) is attached to the pair of end plates (20
It is arranged at the upper part between a) and (20b) and consists of an elongated elastic body with a sharp edge shape at the tip.

The cleaning squeegee support part (5) has the pair of end plates (20a), (20b) l: L-shaped support plates (32) and (33), one of which is the support plate (32). A cleaning squeegee mounting portion (34) is provided on the top to swingably support the cleaning squeegee (4).

Cleaning squeegee (4) is attached to this part (34)
A rag supply reel (
21) and the rag take-up reel (23) supported by the take-up reel support part (24), and is located on the back side of the rag (2) and is swingable in its longitudinal direction. There is.

The approaching/separating mechanism (6) is connected to the Y table (
Air cylinder (17) fixed to the base plate (19)
36), and one support plate (32) of the cleaning squeegee support part (5) is attached to the operating rod of this air cylinder (36). Also, this support plate (3
2), another air cylinder (37) is attached as an auxiliary device for the contact/separation mechanism (6).

This air cylinder (37) is attached to a cleaning squeegee (4) attached to a cleaning squeegee support part (5).
The actuating rod (38
) and adjust the protrusion length of the adjusted actuating rod (38
) and the stopper (39), the amount of retraction of the operating loft of the air cylinder (36), that is, the amount of retraction of the cleaning squeegee (4) is regulated.

This cleaning device operates as follows.

First, the entire cleaning device is moved by the moving mechanism (7) in the X-axis direction where the mask (1) on which the solder paste has been printed is located, and is positioned below the mask (1).

Next, the cleaning squeegee (4) supported by the cleaning squeegee support part (5) is advanced (raised) by the approach/separation mechanism (6), and the tip of the cleaning squeegee (4) is supported by the supply reel support part (22). The rag is wound around the rag supply reel (21) and the rag take-up reel (23) supported by the take-up reel support section (24), and is located between the pair of guide rolls (25a) and (25b). Press the back side of the mask (2), and this pressure presses the cloth (2) against the back side of the mask (1). In this case, the cleaning squeegee (4), which is swingably supported by the cleaning squeegee support part (5) and is made of an elastic body with a sharp edge shape, extends over the entire length of the cleaning squeegee (4). Spread evenly with a rag (2
) on the back of the mask (1).

Then, the entire cleaning device is moved in the X-axis direction again by the moving mechanism (7), and the cleaning squeegee (
Cloth (2) tightly attached to mask (1) due to suppression of 4)
The solder paste adhering to the back surface of this mask (1) is removed. Thereafter, the cleaning squeegee support part (5) is moved backward (downward) by the contact/separation a mechanism (6), and the drive device drives the rag take-up reel (23) to wind up a certain amount of rag (2). Place the new side of (2) on the cleaning squeegee (4).

Note that the width of the effective surface of the mask (1) is wider than the length of the cleaning squeegee (4), and one movement in the X-axis direction by the moving mechanism (A) does not remove the solder paste from the required area. If it is not possible to remove the solder paste from the back of the mask (1) by moving it in the X-axis direction as described above, move the cleaning squeegee (4) in the Y-axis direction using the moving mechanism (A). Then, by moving the cleaning squeegee (4) in the same way, you can clean the wide mask (
The effective surface of 1) can also be cleaned.

Therefore, according to this cleaning device, unlike conventional cleaning using a roll, the dirty part of the rag (2) can be wound up and always cleaned with a new surface of the rag (2), so the mask (1) ) can reliably remove solder paste attached to the back surface of the device. In addition, the cleaning squeegee (4) has an edge-shaped elastic body and is supported in a swingable manner.
The cloth (2) can be evenly attached to the back of the mask (1), and the solder paste attached to the back of the mask (1) can be completely removed without leaving any residue behind, making it possible to use the mask (1) in printing solder paste. By automatically repeating cleaning for each printing, it greatly reduces bridge short defects of raw solder due to solder paste adhering to the back of the mask (1), which tends to occur when printing fine patterns. I can do two things.

In addition, in the above embodiment, the waste path line mechanism is
Either multiple types of rolls such as tension rolls, guide rolls, and drive rolls are arranged between the supply reel support section that supports the rag supply reel and the take-up reel support section that supports the rag take-up reel, or as a rag pass line mechanism. is not limited to the above mechanism, but may also have a structure in which a plurality of guide rolls or the like are arranged.

Furthermore, in the above embodiment, the cleaning squeegee approach/separation mechanism is configured with an air cylinder, but this approach/separation mechanism may also be implemented using a mechanism using a motor as a driving source.

In addition, although the above embodiment describes a cleaning device for a flat metal mask used for printing solder paste, the present invention can also be applied to various other masks by arbitrarily changing the shape, material, hardness, etc. of the cleaning squeegee. It can also be applied to cleaning.

[Effects of the Invention] A mask cleaning device that removes solder paste adhering to the back side of a solder paste printing mask is equipped with a supply reel support section that supports a rag supply reel and a take-up reel support section that supports a rag take-up reel. , a waste pass line mechanism having a drive device for rotationally driving the take-up reel, and a tension applying device for applying tension to the waste cloth stretched from the waste supply reel to the take-up reel; A cleaning squeegee made of an elastic body that presses the back side of the passed rag against the back of the mask, a cleaning squeegee support section that swingably supports the cleaning squeegee, and a cleaning squeegee support section. and a contact MW& mechanism that moves the cleaning squeegee toward and away from the back surface of the rag, and moves the cleaning squeegee together with the rag pass line mechanism and the approach and separation mechanism on a plane perpendicular to the moving direction of the cleaning squeegee by the approach and separation mechanism. By using a moving mechanism that moves the mask, the dirty part of the rag can be wound up and the rag can always be cleaned with a new surface, so that the solder paste attached to the mask can be reliably removed. Furthermore, since the cleaning squeegee is swingably supported, the rag can be evenly brought into close contact with the mask, and the solder paste attached to the mask can be removed without leaving any residue behind. I wanted to,
By automatically repeating the cleaning of the solder paste printing mask after each printing, the solder bridge short that occurs due to the solder paste adhering to the back of the mask, which is easy to break when printing fine patterns, can be greatly reduced. can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the structure of a mask cleaning device which is an embodiment of the present invention, and FIG. 2 is a diagram showing the structure of its main parts. 1... Metal mask 2... Clothes 3...
Wespath line mechanism 4...Cleaning squeegee 5...Cleaning squeegee support section 6...Approach/separation mechanism 7...Movement mechanism 13.
・X table 17...Y table 21...
- Waste supply reel 22... Supply reel support section 23... Waste take-up reel 24... Take-up reel support section 25a, 25b... Guide rolls 26a, 26b 27a, 27b - Tension roll 2
8a, 28b... Drive roll 30... Drive device 34... Cleaning squeegee installation part 36... Air cylinder agent Patent attorney Norio Ogo

Claims (1)

[Claims] A supply reel support part that supports a waste supply reel, a take-up reel support part that supports a waste take-up reel that winds up the waste from the waste supply reel supported by the supply reel support part, and this winding A drive device that rotationally drives a take-up reel supported by the take-up reel support, and a rag that is stretched from the rag supply reel supported by the supply reel support to the take-up reel supported by the take-up reel support. a rag pass line mechanism having a tension applying device that applies tension to the rag; and a back surface of the rag that is stretched from the rag supply reel supported by the supply reel support section to the take-up reel supported by the take-up reel support section; a cleaning squeegee made of an elastic body that presses the rag against the back of the mask by pressing the squeegee; a cleaning squeegee support section that swingably supports the cleaning squeegee; a moving mechanism that moves the cleaning squeegee together with the waste path line mechanism and the approaching/separating mechanism on a plane perpendicular to a direction in which the cleaning squeegee is moved by the approaching/separating mechanism; A mask cleaning device comprising: