JP2009012410A - Cleaning apparatus for printing mask, and printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning apparatus which can more surely clean the surface of a printing mask compared with a case in which the cleaning is performed by pressing a roller-shape cleaning member to the printing mask, and to provide a printer. <P>SOLUTION: This cleaning apparatus is equipped with a cleaning sheet 620 which is spanned on a plurality of supporting rollers 602, 603 and 604, and a cleaning head 610 which presses the cleaning sheet 620 to the printing mask 2. The cleaning sheet 620 and the cleaning head 610 are moved along the rear surface of the printing mask 2 in such a manner that the cleaning sheet 620 being pressed by the cleaning head 610 may rub the rear surface of the printing mask 2. The pressing surface of the cleaning head 610 which presses the cleaning sheet 610 is bent into a projected form regarding the moving direction of the cleaning sheet 620. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cleaning device that cleans a printing mask having a plurality of openings, and a printing device that uses the cleaning device.

2. Description of the Related Art Conventionally, a cleaning roller that is a roller-shaped cleaning member that cleans a metal plate (printing mask) used in a printing apparatus that prints cream solder on a printed wiring board or the like is known (see Patent Document 1). This cleaning roller is composed of a drum-shaped body part with an elastic body bonded to a shaft and a cleaning sheet attached to the body part, and the surface of the roller to which the cleaning sheet is attached directly presses against the surface of the metal plate. Hit.
Japanese Patent Publication No. 7-37135

  However, in the conventional cleaning roller, since the contact width between the roller surface and the surface of the metal plate (printing mask) cannot be increased in the cross section perpendicular to the roller axis, cream solder remains on the back surface of the metal plate. However, there is a possibility that the back surface of the metal plate cannot be reliably cleaned.

  The present invention has been made in view of the above problems, and an object thereof is cleaning that can more reliably clean the surface of a printing mask as compared with the case of cleaning by pressing a roller-shaped cleaning member. An apparatus and a printing apparatus are provided.

In order to achieve the above object, the invention of claim 1 is a cleaning device for cleaning a printing mask in which a plurality of openings are formed, a sheet-like cleaning member stretched around a plurality of support rollers, The pressing member that presses the cleaning member against the printing mask, and the cleaning member and the pressing member of the printing mask are rubbed against the surface to be cleaned of the printing mask so that the cleaning member pressed by the pressing member rubs the surface to be cleaned. Drive means for moving along the surface to be cleaned, and the pressing surface of the pressing member that presses the cleaning member is curved in a convex shape in the moving direction of the cleaning member. .
According to a second aspect of the present invention, in the cleaning device according to the first aspect, a groove extending in a direction intersecting a moving direction of the cleaning member is formed on the pressing surface of the pressing member. Is.
According to a third aspect of the present invention, in the cleaning device of the second aspect, the cleaning member is made of a material through which airflow can pass in the thickness direction, and the opening of the groove formed on the pressing surface of the pressing member. It is characterized by comprising suction means for sucking so as to draw airflow from.
According to a fourth aspect of the present invention, in the cleaning device of the second or third aspect, a plurality of the grooves are arranged in parallel in the moving direction of the cleaning member.
According to a fifth aspect of the present invention, in the cleaning device according to any one of the first to fourth aspects, the radius of curvature of the pressing surface of the pressing member curved in a convex shape in the moving direction of the cleaning member is the pressing surface. Is set in accordance with the pressing amount of the pressing member and the tension of the printing mask so as to follow the bending shape of the printing mask.
According to a sixth aspect of the present invention, in the cleaning device according to any one of the first to fifth aspects, the pressing surface of the pressing member is curved in a convex shape in a direction intersecting the moving direction of the cleaning member. It is a feature.
Further, the invention according to claim 7 is the cleaning device according to claim 6, wherein the radius of curvature of the pressing surface of the pressing member curved in a convex shape in the direction intersecting the moving direction of the cleaning member It is set according to the pressing amount of the pressing member and the tension of the printing mask so as to follow the bending shape of the printing mask.
According to an eighth aspect of the present invention, in the cleaning device according to any one of the first to seventh aspects, the sheet-like cleaning member is a fabric cloth for clean room dust-free clothing.
The invention according to claim 9 is the cleaning device according to any one of claims 1 to 8, wherein the surface portion of the pressing member having the pressing surface is formed of a rigid material. .
The invention according to claim 10 is the cleaning device according to any one of claims 1 to 9, wherein the cleaning member and the pressing member are moved along the surface to be cleaned of the printing mask. Rotation driving means for rotating the support roller so as to rotate is provided.
The invention according to claim 11 is the cleaning device according to any one of claims 1 to 9, wherein the cleaning member and the pressing member are not moved along the surface to be cleaned of the printing mask, Rotation drive means for rotating the support roller so as to rotate the cleaning member until the unused surface of the cleaning member faces the printing mask is provided.
According to a twelfth aspect of the present invention, in the cleaning device according to any one of the first to eleventh aspects, the cleaning member is reciprocated along the surface to be cleaned of the printing mask in a direction intersecting the moving direction of the cleaning member. It is characterized by having means for making it.
Further, the invention of claim 13 sets a printing mask having a plurality of openings formed on a printing object, fills the opening of the printing mask with a printing substance, and then the printing mask and the printing object. A printing apparatus that prints the printing substance on a printing surface of the printing object by separating the printing object, and a cleaning apparatus that cleans the surface of the printing mask that faces the printing object. A cleaning device according to any one of 12 to 12 is used.

  The cleaning device according to claim 1 and the printing device according to claim 13 provided with the cleaning device, wherein the cleaning member and the pressing member are moved along the surface to be cleaned of the printing mask, and the cleaning member pressed by the pressing member is the printing mask. By rubbing the surface to be cleaned, deposits to be cleaned such as printing substances adhering to the surface to be cleaned of the printing mask are removed. Here, since the pressing surface of the pressing member that presses the cleaning member is curved in a convex shape in the moving direction of the cleaning member, the surface of the printing mask bends when the cleaning member pressed by the pressing member contacts. However, the surface to be cleaned of the printing mask can be rubbed with the cleaning member in a state where the convex surface of the cleaning member is brought into contact with the curved surface of the printing mask to increase the contact area between the two. Moreover, the curvature of the pressing surface of the pressing member that presses the cleaning member is different from the outer peripheral surface of the roller-shaped cleaning member whose curvature is determined by the radius, the type of print mask to be cleaned, the pressing force of the cleaning member, etc. By setting relatively freely according to the cleaning conditions, it is possible to secure a contact area between the surface to be cleaned of the printing mask and the surface of the cleaning member.

  Further, in the cleaning device of claim 2 and the printing device of claim 13 provided with the cleaning device, the cleaning member is concentrated on the surface to be cleaned of the printing mask at the corner of the groove formed on the pressing surface of the pressing member. Can be pressed. In this state, the cleaning member rubs against the surface to be cleaned of the print mask, so that the adhered matter adhering to the surface to be cleaned of the print mask can be removed so as to be scraped off, thereby further improving the cleaning performance.

  In the cleaning device according to claim 3 and the printing device according to claim 13 provided with the cleaning device, from the printing mask side, suction is performed so as to draw airflow from the opening of the groove formed in the pressing surface of the pressing member. An air current is generated through the cleaning member and drawn into the opening of the groove formed on the pressing surface of the pressing member. By this air flow, the printing mask is strongly pressed by the cleaning member and the cleaning performance by the cleaning member is enhanced, and the adhering matter adhering to the surface to be cleaned of the printing mask can be removed so as to be sucked in, so the cleaning performance is further enhanced.

  Further, in the cleaning device according to claim 4 and the printing device according to claim 13 provided with the cleaning device, a plurality of grooves on the pressing surface of the pressing member are arranged in parallel in the moving direction of the cleaning member. Since the scraping of the deposit on the surface to be cleaned of the print mask by the corner portion of the groove can be performed in multiple stages at a plurality of locations, the cleaning performance is further enhanced.

The printing mask is bent because the cleaning member is pressed by the pressing member, and the degree of the bending changes depending on the pressing amount of the pressing member and the tension of the printing mask.
Therefore, in the cleaning device according to claim 5 and the printing device according to claim 13 provided with the cleaning device, the pressing surface of the pressing member has a bent shape of the printing mask according to the pressing amount of the pressing member and the tension of the printing mask. The radius of curvature of the pressing surface is set so as to be along. Therefore, regardless of the pressing amount of the pressing member and the size of the tension of the printing mask, the cleaning member pressed by the pressing surface of the pressing member comes into contact with the surface to be cleaned of the printing mask without fail. Since the contact area between the surface to be cleaned of the mask and the surface of the cleaning member can be secured, the cleaning performance is further enhanced.

When both ends of the printing mask in a direction crossing the moving direction of the cleaning member are fixed to the frame, when the cleaning member is pressed against the printing mask, the central portion of the printing mask is recessed in a concave shape. Since it is curved, the pressing force of the cleaning member is increased at both end portions in the crossing direction, and the pressing force of the cleaning member is decreased at the central portion side.
Therefore, in the cleaning device according to claim 6 and the printing device according to claim 13 provided with the cleaning device, the pressing surface of the pressing member is curved in a convex shape in a direction intersecting the moving direction of the cleaning member. Even when both ends of the printing mask in the intersecting direction are fixed to the frame, the difference in the pressing force of the cleaning member between the both ends and the center in the intersecting direction is reduced. Therefore, good cleaning performance can be obtained over the entire printing mask.

The degree of bending of the printing mask in the intersecting direction varies depending on the pressing amount of the pressing member and the tension of the printing mask.
Therefore, in the cleaning device according to claim 7 and the printing device according to claim 13 provided with the cleaning device, the pressing surface of the pressing member intersects the printing mask according to the pressing amount of the pressing member and the tension of the printing mask. The curvature radius of the pressing surface is set so as to follow the bending shape at the intersection. Therefore, regardless of the pressing amount of the pressing member and the size of the tension of the printing mask, the cleaning member pressed by the pressing surface of the pressing member comes into contact with the surface to be cleaned of the printing mask without fail. Since the contact area between the surface to be cleaned of the mask and the surface of the cleaning member can be secured, the cleaning performance is further enhanced.

  In the cleaning device according to claim 8 and the printing device according to claim 13 provided with the cleaning device, since the sheet-like cleaning member is a woven fabric, fiber dust is generated as compared with a non-woven fabric. It is difficult to prevent the printing mask from being contaminated with fiber waste. In addition, since the cloth used for the cleaning member is a cloth for clean room dust-free clothing, the fiber dust is less likely to be generated.

When the surface portion having the pressing surface of the pressing member is formed of an elastic body, a part of the cleaning member pressed against the printing mask by the pressing member is deformed so as to enter the opening of the printing mask. The printing material remaining on the inner wall surface of the opening is scraped off. The printing material scraped from the inner wall surface of the opening of the printing mask by the cleaning member adheres to the surface to be cleaned of the printing mask and contaminates the printing mask, leading to a reduction in cleaning performance.
Therefore, in the cleaning device according to claim 9 and the printing device according to claim 13 provided with the cleaning device, the pressing member is pressed against the printing mask by forming the surface portion having the pressing surface with a rigid material. Since the cleaning member is difficult to be deformed so as to enter the opening of the printing mask, it is possible to prevent contamination of the surface to be cleaned by the printing material scraped from the inner wall surface of the opening of the printing mask.

  The cleaning device according to claim 10 and the printing device according to claim 13 provided with the cleaning device rotate the cleaning member and the pressing member while moving the cleaning member and the pressing member along the surface to be cleaned of the print mask. Thus, the relative moving speed of the cleaning member with respect to the surface to be cleaned of the printing mask can be increased, and the cleaning performance is further improved.

  Further, in the cleaning device of claim 11 and the printing device of claim 13 provided with the cleaning device, the cleaning member and the pressing member are not moved along the surface to be cleaned of the printing mask, and the printing mask is placed on the cleaning standby. The cleaning member is rotated until the unused surfaces of the cleaning member face each other. The rotation of the cleaning member during the cleaning standby prevents the used portion of the cleaning member from being reused for cleaning the print mask. Therefore, the print mask is contaminated by the material once removed from the print mask by the cleaning member. Can be prevented.

  In the cleaning device according to claim 12 and the printing device according to claim 13 provided with the cleaning device, the cleaning member is reciprocated along the surface to be cleaned of the print mask in a direction intersecting the moving direction of the cleaning member. The cleaning member is rubbed against the surface to be cleaned of the print mask in the direction of the intersection. Thereby, the removal efficiency of the cleaning member with respect to the deposit | attachment adhering to the to-be-cleaned surface of a printing mask can be improved.

  According to the present invention, since the pressing surface of the pressing member that presses the cleaning member is curved in a convex shape in the moving direction of the cleaning member, the surface of the printing mask is brought into contact with the cleaning member pressed by the pressing member. Can be rubbed against the surface to be cleaned of the printing mask with the cleaning member in a state where the curved surface of the printing mask is brought into contact with the convex surface of the cleaning member to increase the contact area between the two. . Moreover, the curvature of the pressing surface of the pressing member that presses the cleaning member is different from the outer peripheral surface of the roller-shaped cleaning member whose curvature is determined by the radius, the type of print mask to be cleaned, the pressing force of the cleaning member, etc. By setting relatively freely according to the cleaning conditions, it is possible to secure a contact area between the surface to be cleaned of the printing mask and the surface of the cleaning member. Therefore, there is an effect that the surface of the printing mask can be more reliably cleaned as compared with the case where the roller-shaped cleaning member is pressed and cleaned.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a process diagram showing an example of an entire substrate manufacturing method including a printing process employing a printing method according to an embodiment of the present invention. 2A and 2B are respectively an explanatory view and a plan view showing an example of a cross-sectional structure of the electronic circuit board 1 manufactured by the substrate manufacturing method of the present embodiment.
As shown in FIG. 2A, the substrate 1 includes a surface mounting resin exterior component (hereinafter referred to as “resin exterior chip”) 1b as a first electronic component and a surface mounting as a second electronic component. This is an electronic circuit board on which a bare chip component (hereinafter simply referred to as “bare chip”) 1c is mounted. The resin exterior chip 1b is a component such as a semiconductor IC sealed with resin, a resistor, and a capacitor, and the bare chip 1c is a bare semiconductor IC chip before being sealed with resin. Between the substrate 1 and the bare chip 1c, a resin 55 is filled so that the bare chip 1c is stably fixed on the substrate 1. On the other hand, the resin is not filled between the substrate 1 and the resin exterior chip 1b.

  Further, as shown in FIG. 2B, the substrate 1 is a substrate in which a large number (for example, several tens to several hundreds) of individual substrates 1a having a predetermined function and the same shape and circuit specifications are arranged in a lump. It is. The substrate 1 is separated into individual substrates 1a after the resin-coated chip 1b and the bare chip 1c are mounted and subjected to a predetermined function test. Each of the separated individual substrates 1a is used as a circuit module component having a predetermined function.

In the substrate manufacturing method shown in FIG. 1, first, a solder printing step (printing a cream solder 3 as a conductive printing substance (printing agent) on the substrate 1 before mounting the resin-coated chip 1b or the bare chip 1c ( P1) is executed. After this solder printing step, the same mounting component (1) mounts the resin-coated chip 1b at a predetermined position on the substrate 1 (P2) and the bare chip 1c at a predetermined location on the substrate 1. And a second mounting step (P3) to be mounted on. Note that the order of the first mounting step and the second mounting step may be reversed.
Next, a reflow process (P4) is performed after the mounting process of the resin exterior chip 1b and the bare chip 1c. Thus, after performing two mounting processes (P2, P3), the reflow process is performed, whereby the number of heating times for the electronic components on the substrate 1 can be reduced.
Next, after the reflow step, an underfill processing step (P5) is performed in which a gap between the substrate 1 and the bare chip 1c is filled with a resin 55 as a filler that fills the gap.
As described above, the exterior chip 1b not subjected to the underfill process and the bare chip 1c subjected to the underfill process can be mixedly mounted on the same substrate 1.

  As mentioned above, according to the board | substrate manufacturing method of this embodiment, since the frequency | count of a heating with respect to the electronic component mounted on the board | substrate 1 can be reduced, the frequency | count of the heat shock given to these electronic components can be reduced. Moreover, since the reflow process of the resin exterior component 1b and the reflow process of the bare chip 1c, which were conventionally performed individually, are simultaneously performed, the number of processing steps can be reduced and workability can be improved.

  A substrate manufacturing system capable of realizing the above-described substrate manufacturing method includes, for example, a printing apparatus that prints cream solder 3 on a predetermined electrode of the substrate 1, and component mounting that positions and mounts the component at a predetermined position on the substrate 1 A mounting device as a device, a reflow device that heats the substrate 1 on which the bare chip 1c and the resin-coated chip 1b are mounted, and an underfill device that fills the gap between the bare chip 1c and the substrate 1 with the resin 55 are configured. be able to.

  FIG. 3 is a schematic configuration diagram illustrating an example of a printing apparatus that can be used in a printing method (solder printing process). This printing apparatus prints cream solder 3 as a conductive printing substance (printing agent) on a substrate 1 by using a printing mask 2 which is a stencil mask made of a sheet-like plastic material. The printing mask 2 includes a plurality of openings 201 penetrating in the thickness direction formed according to a predetermined printing pattern, and using a capsule on a rectangular mask mounting frame 20 as a mask mounting member with a predetermined tension. It is directly pasted without. The printing mask 2 attached to the mask attachment frame 20 is supported by a mask frame holding member 40 as mask support means.

  The substrate 1 is held on the stage 5 so that the electrode forming surface (printed surface) on which the electrodes are formed is the upper surface. On the lower surface of the stage 5, there is provided a substrate drive unit 7 as drive means for moving the stage 5 linearly along the vertical direction perpendicular to the electrode formation surface (printed surface) of the substrate 1. The substrate driving unit 7 is configured by using a stepping motor 700 that can rotate forward and backward, and a stage vertical movement mechanism 701 that includes a ball screw and a nut (not shown) that is rotationally driven by the motor 700. By controlling the rotation of the stepping motor 700, the stage 5 is driven in the vertical direction, and the substrate 1 is raised to a predetermined printing position in contact with the printing mask 2 or lowered so as to be separated from the printing mask 2. Can be.

  Further, a filling means for filling the cream solder 3 into the opening 201 of the printing mask 2 is provided above the stage 5 moved to the printing position. This filling means includes a squeegee 8 as a filling member for imprinting the cream solder 3 into the opening 201 of the printing mask 2, a squeegee drive unit (not shown) for driving the squeegee 8 in the left-right direction in the figure by a drive belt or the like. It is comprised by.

  As the cream solder printed on the substrate 1, a solder containing a predetermined solder or an additive is used according to the type of the substrate 1 to be printed and the electronic component to be soldered. For example, the cream solder used when printing using the fine pattern printing mask 2 is preferably, for example, a solder having an average particle size of 10 μm or less and a flux component content of about 11% by mass.

  The printing mask 2 is provided with a plurality of openings 201 respectively corresponding to electrodes on which various electronic components are mounted. The opening 201 is a through-hole penetrating in the thickness direction of the print mask, and the shape and size in the print surface direction are set according to the size and shape of the electrode to be printed. For example, when printing a micro print pattern, the size and shape of the opening 201 is a quadrangle having a side of about 100 to 200 μm or a circle having a diameter of the same size. Moreover, as the base sheet of the printing mask 2, for example, a plastic sheet such as biaxially stretched PET (polyethylene terephthalate) or polyimide having a thickness of several tens to several hundreds of micrometers (about 150 μm as a more preferable specific example) is used. Further, the opening is formed by performing laser irradiation, electric discharge machining, press working or the like on the base sheet. In addition, a conductive film made of a polyurethane resin containing carbon may be formed on the surface of the base sheet that is in contact with the object to be printed as a film having a thermal contraction rate larger than that of the base sheet. By forming a conductive film in this way, when printing using the printing mask 2, it is possible to prevent damage to the device on the printed object (substrate) due to static electricity during squeezing or peeling of the printing mask. Can do.

  When the cream solder 3 is printed using the printing mask 2 as in the above printing apparatus, as shown in FIG. 4, a part 3 ′ of the cream solder filled in the opening 201 of the printing mask 2 is replaced with the printing mask. There is a risk of sneaking between the back surface of 2 (the surface facing the substrate) and the substrate 1 and adhering to the back surface of the printing mask 2. The deposits adhering to the back surface of the print mask 2 may adhere to an unscheduled region of the substrate 1 in the next printing process, and may cause problems such as contamination of the substrate 1 or short circuit. Therefore, in the printing apparatus of the present embodiment, the back surface (the surface facing the substrate) of the printing mask 2 is cleaned at a predetermined timing by a cleaning device described later. In particular, when the cream solder 3 for chip mounting is printed on a large number of individual substrates on the substrate 1 at once, and the solder paste 3 having solder particles having a fine particle size (for example, about 10 μm or less) is used. It is difficult to reliably remove the cream solder that remains and adheres to the back surface of the printing mask 2. For this reason, in the present embodiment, the print mask 2 is cleaned using a cleaning device having higher cleaning performance than the conventional one, as will be described below.

  FIG. 5 is a schematic configuration diagram illustrating an example of a printing apparatus for cleaning the print mask 2. When cleaning the printing mask 2 used once or a plurality of times for the printing of the cream solder 3, the stage 5 and the substrate driving unit 7 of the substrate 1 set under the printing mask 2 are connected to the cleaning device 6. Replace. Alternatively, the printing mask 2 set above the stage 5 of the substrate 1 and the substrate driving unit 7 may be moved and set on the cleaning device 6. The cleaning device 6 is driven so that the cleaning head unit 601 set on the main body stage unit 600 moves in a direction along the back surface of the printing mask 2 (B direction in the drawing). One cleaning process of the printing mask 2 may be completed by moving once in one direction (one-way movement) along the back surface of the printing mask 2 or once along the back surface of the printing mask 2. Or you may complete by moving so that it may reciprocate several times. Further, the main body stage unit 600 may be configured so that the relative position of the cleaning head unit 601 in the vertical direction with respect to the print mask can be adjusted.

  As shown in FIGS. 3 and 5, the cleaning device 6, the substrate driving unit 7, and the squeegee driving unit are controlled by a main control unit 100 as control means configured by a computer device including a CPU, RAM, ROM, and the like. The The main control unit 100 reads a program and various control data from the storage device 102 constituted by a hard disk or the like based on a processing instruction input by the operator from the input device 101, and executes the read program to thereby print a mask. The cleaning device 6, the substrate driving unit 7, the squeegee driving unit, and the like are controlled so as to perform a predetermined printing process including a cleaning process.

  FIG. 6 is a schematic configuration diagram showing a configuration example of the cleaning head unit 601. The cleaning head unit 601 includes a sheet-like cleaning member (hereinafter referred to as “cleaning sheet”) 620. The cleaning sheet 620 has an endless belt shape, and is stretched over a plurality of support rollers 602, 603, and 604 and a cleaning head 610 as a sheet pressing member. The support roller 602 also functions as a tension roller for adjusting the tension applied to the cleaning sheet 620, and the support roller 603 rotates the cleaning sheet 620 in the counterclockwise direction indicated by arrow D in the drawing at a predetermined timing. It also functions as a rotational drive roller for the The support roller (rotation drive roller) 603 is connected to a rotation shaft of a motor as a rotation drive source (not shown) via a drive transmission member such as a gear.

  The cleaning head 610 can be lifted to press against the print mask 2 or lowered to be separated from the print mask 2 by the head vertical movement device 15. As the head vertical movement device 15, for example, an air cylinder supplied with a gas of a predetermined pressure from a gas supply device, a ball screw rotated by a drive motor, or the like can be used. Further, the cleaning head 610 is controlled to stop rising at a predetermined upper limit position. For example, a stopper such as a micro switch that operates when the cleaning head 610 reaches a predetermined upper limit position is provided, and the head vertical movement device 15 is configured to stop the upward driving of the cleaning head 610 based on the output of the stopper. To control. Further, a sensor for detecting the tension of the cleaning sheet 620 is provided, and when the output of the sensor reaches a predetermined magnitude, it is determined that the cleaning head 610 has reached a predetermined upper limit position, and the cleaning head 610 is raised. The head vertical movement device 15 may be controlled to stop driving.

  Further, as will be described later, the pressing surface of the cleaning head 610 is curved in a convex shape with respect to the moving direction of the cleaning sheet 620 (the direction of arrow B in the figure). The cleaning head unit 601 including at least the cleaning head 610 and the cleaning sheet 620 is placed on the back surface of the print mask 2 so that the cleaning sheet 620 pressed by the cleaning head 610 rubs the back surface that is the surface to be cleaned of the print mask 2. A cleaning unit driving mechanism is provided as a driving means for moving along.

  FIG. 7 is a schematic configuration diagram showing another configuration example of the cleaning head unit 601. The cleaning head unit 601 is different from the unit shown in FIG. 6 in that a winding-type cleaning sheet 620 is used instead of the endless belt-like cleaning sheet 620, and a sheet supply roller is used instead of the support roller (rotation drive roller) 603. 606 and a sheet collection roller 605 are provided. Of these two rollers 605 and 606, at least the sheet collection roller 605 also functions as a rotation driving roller for rotating the cleaning sheet 620 in the counterclockwise direction indicated by an arrow D in the drawing at a predetermined timing. By this rotation, the used portion of the cleaning sheet 620 is collected by the sheet collecting roller 605 and the unused portion of the cleaning sheet 620 is supplied from the sheet supply roller 606.

  FIG. 8 is a schematic configuration diagram showing still another configuration example of the cleaning head unit 601. Unlike the unit shown in FIG. 6, the cleaning head unit 601 has a simple configuration in which a cleaning sheet 620 is stretched over two support rollers 607a and 607b. One of the two support rollers 607a and 607b also functions as a rotation driving roller for rotating the cleaning sheet 620 in the counterclockwise direction indicated by an arrow D in the drawing at a predetermined timing.

  FIG. 9 is a schematic configuration diagram showing still another configuration example of the cleaning head unit 601. This cleaning head unit 601 is different from the unit shown in FIG. 8 in that a winding-type cleaning sheet 620 is used instead of the endless belt-like cleaning sheet 620, and a sheet collection roller 608a is provided instead of the support roller 607a. A sheet supply roller 608b is provided instead of the roller 607b. Of these two rollers 608a and 608b, at least the sheet collection roller 608a also functions as a rotation driving roller for rotating the cleaning sheet 620 in the counterclockwise direction indicated by an arrow D in the drawing. By this rotation, the used portion of the cleaning sheet 620 is collected by the sheet collection roller 608a, and the unused portion of the cleaning sheet 620 is supplied from the sheet supply roller 608b.

  The cleaning sheet 620 may be rotated when the cleaning head unit 601 is moved, or the unused surface of the cleaning sheet 620 on the printing mask 2 during the cleaning standby without moving the cleaning head unit 601. The cleaning sheet 620 may be rotationally driven until they face each other.

  FIGS. 10A, 10B, and 10C are respectively a front sectional view, a side sectional view, and a plan view showing one configuration example of the cleaning head 610 that constitutes the cleaning head unit 601. The pressing surface 610a of the cleaning head 610 is curved in a convex shape with a predetermined curvature radius in each of two directions intersecting each other along the surface. More specifically, the pressing surface 610a of the cleaning head 610 is curved with a radius of curvature R1 in the moving direction (short direction) of the cleaning head 610 and the cleaning sheet 620 at the time of cleaning, and in the longitudinal direction orthogonal to the moving direction. It is curved with a radius of curvature R2. These curvature radii R1 and R2 are such that the pressing surface 610a follows the bending shape of the printing mask 2, the amount of pressing of the cleaning head 610, the material (base sheet) of the printing mask 2, the tension and the mask mounting frame 20 Is set according to the size of the frame (in particular, the size inside the frame). For example, when the material (base sheet) of the printing mask 2 is PET and the size of the mask mounting frame 20 is about 550 to 650 mm, the curvature radii R1 and R2 are several thousand mm to several 10000 mm (more preferably 9200 mm). Degree). Since the pressing surface 610a of the cleaning head 610 is curved in a convex shape with a predetermined curvature in this way, the cleaning sheet 620 pressed by the cleaning head 610 contacts as shown in FIGS. 11 (a) and 11 (b). Thus, even if the surface of the printing mask 2 is bent, the back surface of the printing mask 2 in a state where the curved surface of the printing mask 2 is brought into contact with the curved surface of the cleaning sheet 620 to increase the contact area between the two. The (cleaning surface) can be rubbed with the cleaning sheet 620.

  FIG. 12 is an explanatory diagram of the pressing amount ΔD of the cleaning head 610. The distance (height of the convex portion) between the center upper end of the pressing surface 610a of the cleaning head 610 and the reference horizontal plane is ΔD1, and the distance between the reference horizontal plane of the pressing surface 610a of the cleaning head 610 and the lower surface of the print mask 2 is Assuming ΔD2, the pressing amount ΔD of the cleaning head 610 against the print mask 2 is the sum of ΔD1 and ΔD2. For example, when ΔD1 and ΔD2 are 0.78 mm and 1.85 mm, respectively, the pressing amount ΔD is 2.63 mm. Moreover, when the tension (elongation amount) of the center part and the edge part of the printing mask 2 in this numerical example was measured, it was 0.58 mm and 0.53 mm.

  The surface portion having the pressing surface 610a of the cleaning head 610 is preferably formed of a rigid material instead of an elastic material. By forming the surface portion of the cleaning head 610 with a rigid material in this way, the cleaning sheet 620 pressed against the print mask 2 by the cleaning head 610 is not easily deformed so as to enter the opening 201 of the print mask 2. Therefore, contamination of the back surface (surface to be cleaned) by the cream solder 3 scraped from the inner wall surface of the opening 201 of the printing mask 2 can be prevented.

  In addition, a plurality of grooves 611, 612, and 613 extending in the longitudinal direction perpendicular to the moving direction of the cleaning head 610 and the cleaning sheet 620 during cleaning are formed on the pressing surface 610 a of the cleaning head 610. Of these grooves, the central groove 611 is a through-hole penetrating to the back side. In the cleaning operation, air is sucked from the upper opening through the through hole of the groove 611. The suction means for sucking the airflow includes a suction airflow path formed in a base member (not shown) to which the cleaning head 610 is fixed by screwing through the mounting hole 614, a vacuum pump, and the suction airflow path and the vacuum pump. It is composed of piping provided so as to connect the two.

  FIG. 13 is an explanatory diagram showing the relationship between the grooves 611, 612 and 613 of the cleaning head 610 and the size of the print mask 2. The length Lc1 in the longitudinal direction of the convex portion where the pressing surface 610a of the cleaning head 610 is formed is shorter than the size Lm1 inside the mask mounting frame 20 so as not to interfere with the mask mounting frame 20 of the printing mask 2. Is set. In addition, the length Lc2 of the groove having the shortest length in the longitudinal direction among the grooves formed on the pressing surface 610a of the cleaning head 610 (in this embodiment, the central through groove 611) is the length Lc2 of the printing mask 2. The length is set to be longer than the length Lm2 of the opening forming region 202 so that at least the opening forming region (printing region) 202 in which the opening 201 is formed can be cleaned. Also, the width of the cleaning sheet 620 is set longer than the length Lm2 of the opening forming region 202 so that the cleaning sheet 620 can be cleaned in contact with the opening forming region 202 of the printing mask 2. Further, the width of the cleaning sheet 620 is such that the pressing surface 610a is formed so that the end of the cleaning sheet 620 in the width direction is not damaged at the corner of the convex portion where the pressing surface 610a of the cleaning head 610 is formed. It is preferable to set the length of the convex portion shorter than the length Lc1 in the longitudinal direction. In order to prevent the opening of the central through groove 611 formed in the pressing surface 610a of the cleaning head 610 from being exposed and applying an excessive load to the suction means, the width of the cleaning sheet 620 is set to the width of the through groove 611. It is preferable to set the length longer than the length Lc2.

  The cleaning head 610 may be composed of a plurality of members divided in the short direction perpendicular to the longitudinal direction. For example, the cleaning head 610 may be composed of three members: a central head member having the central groove 611 and an upstream head member and a downstream head member having grooves 612 and 613 on both sides thereof. . In this case, the protrusion amounts of the three members, that is, the central head member, the upstream head member, and the downstream head member, with respect to the print mask 2 may be set independently of each other.

  The material of the cleaning sheet 620 is preferably a clean cloth-free cloth (cloth type) cloth that is less likely to generate fiber dust so that the print mask can be prevented from being contaminated by fiber dust. Further, the cross-sectional shape of the fiber of the cloth used for the cleaning sheet 620 is preferably not a circle but a polygon (for example, a triangle) that can easily entrain cream solder as a substance to be cleaned. Furthermore, the fibers of the cloth used for the cleaning sheet 620 are preferably thin and have a high density. More specifically, the size (thickness) of the cleaning sheet 620 in the fiber cross section is preferably in the range of 1 to 10 μm (more preferably in the range of 2 to 9 μm).

  If the fibers of the cleaning sheet 620 are too thin or the density is too high, the fibers become too weak, and there is a risk that the solder once taken into the fibers will be released (returned to the printing mask side). The lower limit of the thickness and the upper limit of the density are preferably set in consideration of a balance with the fiber knitting method and the like.

Furthermore, as the material of the cleaning sheet 620, for example, a sheet of resin fiber made of nylon 6 (content: 50%) and polyester (content: 50%), polyethylene terephthalate (content: 66.6%), A sheet of resin fiber containing polycaprolactamamide (content 62.8%) and titanium dioxide (content: less than 0.3) can be used. By knitting resin fibers made of the materials as exemplified above at a basis weight (density): about 100 to 200 g / m ² and a thickness: about 0.18 mm to form a cloth (cross), a cross-type sheet is obtained. be able to. Moreover, a nonwoven fabric type sheet may be used as long as the same characteristics as those of the cloth type sheet can be obtained.

  As the cleaning sheet 620, a commercially available resin fiber sheet can be used. For example, product name: “Benlyse (registered trademark)” manufactured by Asahi Kasei Fibers Co., Ltd., model: TS100-350 * 18, product name manufactured by NI Teijin Shoji Co., Ltd .: “Microstar (registered trademark)”, model: G89001 are used. be able to.

  In cleaning the printing mask 2, it is preferable to use the cleaning sheet 620 in a dry state without spraying a solvent (for example, IPA: isopropyl alcohol) or the like on the cleaning sheet 620. When the solvent or the like is sprayed, the flux component of the cream solder remaining in the opening 201 of the print mask 2 is drawn out to the back side of the print mask 2, and in the next printing process using the print mask 2. There is a risk of printing failure.

As described above, according to the cleaning device for the printing mask 2 and the printing device including the same in the present embodiment, the pressing surface 610a of the cleaning head 610 that presses the cleaning sheet 620 is the moving direction of the cleaning head unit 601 (cleaning sheet 620). Therefore, even if the printing mask 2 is bent by the contact of the cleaning sheet 620 pressed by the cleaning head 610, the cleaning sheet 620 is curved on the curved back surface of the printing mask. The back surface of the printing mask 2 can be rubbed with the cleaning sheet 620 in a state where the front surfaces are in contact with each other and the contact area between the both is increased. Moreover, the curvature of the pressing surface 610a of the cleaning head 610 that presses the cleaning sheet 620 is different from the outer peripheral surface of the conventional cleaning roller in which the curvature is determined by the radius, and the type of the printing mask 2 to be cleaned and the cleaning sheet 620 are different. The contact area between the back surface of the printing mask 2 and the cleaning sheet 620 can be secured by setting relatively freely according to the cleaning conditions such as the pressing force. Therefore, the surface of the printing mask 2 can be more reliably cleaned as compared with the case of cleaning by pressing a cleaning roller which is a conventional roller-shaped cleaning member.
Further, according to the present embodiment, the cleaning sheet 620 can be intensively pressed against the back surface of the printing mask 2 at the corners of the grooves 611, 612, and 613 formed on the pressing surface 610 a of the cleaning head 610. . In this state, the cleaning sheet 620 rubs the back surface of the print mask 2 so that the attached matter such as cream solder 3 attached to the back surface of the print mask 2 can be removed so as to be further cleaned. Will increase.
Further, according to the present embodiment, the suction of the airflow is drawn through the opening of the central groove 611 formed in the pressing surface 610a of the cleaning head 610, thereby opening the central groove 611 through the cleaning sheet 620 from the printing mask 2 side. An air current that draws in is generated. By this air flow, the printing mask 2 is strongly pressed by the cleaning sheet 620 and the cleaning performance by the cleaning sheet 620 is improved, and the attached matter such as cream solder 3 attached to the back surface of the printing mask 2 can be removed so as to be sucked. Further, the cleaning performance is enhanced.
In addition, according to the present embodiment, a plurality of grooves 611, 612, and 613 are arranged in parallel on the pressing surface 610a of the cleaning head 610, so that the deposits on the back surface of the print mask 2 due to the corner portions of the grooves described above. Since scraping can be performed in multiple stages at a plurality of locations, the cleaning performance is further enhanced.
Further, according to the present embodiment, the pressing surface 610a of the cleaning head 610 is curved in a convex shape with respect to the longitudinal direction intersecting the moving direction of the cleaning head unit 601 (cleaning sheet 620). Even when both ends of the mask 2 are fixed to the frame body 20, the difference in the pressing force of the cleaning sheet 620 between the both ends and the center in the longitudinal direction becomes small. Therefore, good cleaning performance can be obtained over the entire printing mask 2.

  In particular, according to the present embodiment, the cream solder 3 for chip mounting is collectively printed on a large number of individual substrates on the substrate 1, and the solder having a fine particle diameter (for example, about 10 μm or less) is used as the cream solder 3. Even in the case of performing high-definition printing using particles having particles, the cream solder that remains and adheres to the back surface of the printing mask 2 can be reliably removed. In the case of a conventional cleaning device using a cleaning roller, a belt-like cleaning defective region occurs in the central portion of the printing region of the printing mask 2 used for such high-definition printing along the cleaning member moving direction. . On the other hand, when the cleaning device of the present embodiment is used, a good cleaning performance can be obtained over the entire back surface of the print mask without the occurrence of the belt-like defective cleaning area.

  FIG. 14 shows the results of a cleaning test in which the cleaning performance was measured when the printing mask 3 was cleaned using the cleaning device 6 having the configuration shown in FIG. In this cleaning test, a fabric cloth for clean room dust-free clothing having a fiber thickness of 2 to 9 μm was used as the cleaning sheet 620. Using this cleaning device 6, the cleaning head unit 601 was reciprocated once so as to clean the back surface of the printing mask 3 used in one printing process. Thereafter, the solder balls remaining on the back surface of the printing mask 2 were observed with a microscope, and the “wiping rate” was determined. Here, the “wiping rate” is obtained by dividing the area of the entire region (all cleaned regions) observed with a microscope into a plurality of observation sections, and one solder ball remains in the total number (N0) of the observation sections. This is the ratio of the number of observation sections (N1) that have not been performed. That is, the “wiping rate” (%) was calculated by N1 ÷ N0 × 100. The printing using the printing mask 2, the cleaning of the printing mask 2, and the measurement of the cleaning performance were repeated five times using the same printing mask 2.

  As shown in FIG. 14, in the cleaning device 6 of this embodiment, when a cleaning sheet 620 made of a fabric cloth for clean room dust-free clothing having a fiber thickness of 2 to 9 μm is used, printing is performed five times. Even in such a case, good cleaning performance with a wiping rate of 80% or more was obtained. On the other hand, when a nonwoven fabric having a fiber thickness of 13 to 16 μm is used as the cleaning sheet, the cleaning performance deteriorates every time printing and cleaning are repeated, as shown in FIG. "Rate" dropped to about 20-40%.

  In the above embodiment, the cleaning sheet 620 is disposed along the back surface (surface to be cleaned) of the printing mask 2 in the longitudinal direction of the cleaning head 610, which is the direction intersecting the moving direction of the cleaning head unit 601. May be reciprocated (vibrated). As described above, the cleaning sheet 620 is reciprocated in the longitudinal direction of the cleaning head 610, whereby the cleaning sheet 620 is slid against the back surface of the print mask 2 in the longitudinal direction. Thereby, the removal efficiency with respect to the deposit | attachment adhering to the back surface of the printing mask 2 can be improved.

FIGS. 16A to 16C are explanatory views of the configuration in which the cleaning sheet 620 is reciprocated in the longitudinal direction together with the cleaning head 610 as viewed from above.
In the example of FIG. 16A, an air cylinder 631 as a head reciprocating means for reciprocating the cleaning head 610 in the longitudinal direction is provided at the longitudinal end of the cleaning head 610. The reciprocating means by the air cylinder 631 may be combined with a compression spring and a tension spring. In this example, when the cleaning head unit 601 is moved in the horizontal direction B in the figure, the air supply to the air cylinder 631 is intermittently performed or the pressure of the supply air is changed. Accordingly, the cleaning head 610 can be reciprocated in the longitudinal direction (E direction in the drawing), and the cleaning sheet 620 against which the cleaning head 610 is pressed can be reciprocated in the same direction.
In the example of FIG. 16B, an ultrasonic generator 632 as a head reciprocating means (microvibration applying means) for reciprocating the cleaning head 610 in the longitudinal direction is connected to the longitudinal end of the cleaning head 610. Has been. The ultrasonic generator 632 can be configured using, for example, a piezoelectric element. In this example, when the cleaning head unit 601 is moved in the horizontal direction B in the figure, the cleaning head 610 is reciprocated in the longitudinal direction (E direction in the figure) by the ultrasonic waves generated by the ultrasonic generator 632. The cleaning sheet 620 against which the cleaning head 610 is pressed can be reciprocated (vibrated) in the same direction.
Further, in the example of FIG. 16C, as a head reciprocating means for reciprocating the cleaning head 610 in the longitudinal direction on the side surface of the cleaning head 610, a rotating member 633 that is rotationally driven by a motor or the like and the rotating member 633. A drive conversion mechanism 634 is provided that converts the rotational movement into a linear movement in the longitudinal direction and transmits the linear movement to the cleaning head 610. The reciprocating means by the air cylinder 631 may be combined with a compression spring and a tension spring. In this example, when the cleaning head unit 601 is moved in the horizontal direction B in the figure, the rotating member 633 is rotated intermittently or rotated while the rotating direction of the rotating member 633 is switched. Accordingly, the cleaning head 610 can be reciprocated in the longitudinal direction (E direction in the drawing), and the cleaning sheet 620 against which the cleaning head 610 is pressed can be reciprocated in the same direction.

16A to 16C, when the cleaning head 610 reciprocates in the longitudinal direction, if the cleaning head 610 and the cleaning sheet 620 move relative to each other, the rubbing, etc. As a result, wings and fibers are cut off on the back surface of the cleaning sheet 620, and the back surface of the cleaning sheet 620 can no longer be used for cleaning the print mask. Or may adhere to the product to be printed.
Therefore, it is preferable that the cleaning head 610 and the cleaning sheet 620 are configured not to move relative to each other when the cleaning head 610 and the cleaning sheet 620 are reciprocated in the longitudinal direction. For example, a guide member and a stop clamp are provided so that the cleaning sheet 620 does not deviate from a predetermined position in the longitudinal direction on the cleaning head 610. Further, a means for sucking the cleaning sheet 620 on the cleaning head 610 side and a means for maintaining the tension of the cleaning sheet 620 at a predetermined tension may be provided.

  In the above embodiment, the printing mask 2 is fixed and the cleaning head unit 601 is moved to clean the printing mask 2. However, the cleaning head unit 601 is fixed and the printing mask 2 is moved. Also good.

  Moreover, although the said embodiment demonstrated the case where the printing target object was the board | substrate 1, this invention is applicable also when printing on the surface of electronic components, such as semiconductor wafers other than the board | substrate 1, as a printing target object.

Process drawing which shows an example of the whole board | substrate manufacturing method including the printing process using the printing apparatus which concerns on embodiment of this invention. (A) And (b) is explanatory drawing and a top view which show an example of the cross-sectional structure of the electronic circuit board manufactured with the same board | substrate manufacturing method, respectively. 1 is a schematic configuration diagram illustrating an example of a printing apparatus during printing. Explanatory drawing of the stain | pollution | contamination of the solder adhering to the back surface of a printing mask. 1 is a schematic configuration diagram illustrating an example of a printing apparatus during cleaning according to an embodiment of the present invention. FIG. 3 is a schematic configuration diagram illustrating a configuration example of a cleaning head unit of the cleaning device according to the embodiment of the invention. The schematic block diagram which shows the other structural example of a cleaning head unit. The schematic block diagram which shows the further another structural example of a cleaning head unit. The schematic block diagram which shows the further another structural example of a cleaning head unit. (A), (b) and (c) are front sectional drawing, side sectional drawing, and top view which show the example of 1 structure of the cleaning head which comprises a cleaning head unit, respectively. (A) And (b) is explanatory drawing which shows the mode of the printing mask which is pressed and bent by the cleaning head. Explanatory drawing of the pressing amount of a cleaning head. Explanatory drawing which shows the relationship between each groove | channel of a cleaning head, and the size of a printing mask. The graph which shows the measurement result of the cleaning performance at the time of using the cleaning sheet of one Example of this invention. The graph which shows the measurement result of the cleaning performance at the time of using the cleaning sheet of a comparative example. (A)-(c) is explanatory drawing of the structure which reciprocates a cleaning sheet with a cleaning head in a longitudinal direction, respectively.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Board | substrate 2 Print mask 3 Cream solder 5 Stage 6 Cleaning apparatus 7 Board drive unit 8 Squeegee 20 Mask mounting frame 41, 42 Mask frame holding member 600 Main body stage part 601 Cleaning head unit 601a Pressing surface 602, 603, 604 Support roller 610 Cleaning Head 611 groove (through hole)
612, 613 groove 620 cleaning sheet

Claims (13)

A cleaning device for cleaning a printing mask having a plurality of openings formed therein,
A sheet-like cleaning member stretched over a plurality of support rollers;
A pressing member that presses the cleaning member against the printing mask;
Drive means for moving the cleaning member and the pressing member along the surface to be cleaned of the printing mask so that the cleaning member pressed by the pressing member rubs the surface to be cleaned of the printing mask;
A cleaning device, wherein a pressing surface of the pressing member that presses the cleaning member is curved in a convex shape in a moving direction of the cleaning member. The cleaning device according to claim 1.
A cleaning device, wherein a groove extending in a direction intersecting a moving direction of the cleaning member is formed on a pressing surface of the pressing member. The cleaning device according to claim 2.
The cleaning member is made of a material through which airflow can pass in the thickness direction,
A cleaning device, comprising: suction means for sucking air so as to be drawn from an opening of the groove formed on the pressing surface of the pressing member. The cleaning device according to claim 2 or 3,
A cleaning device, wherein a plurality of the grooves are arranged in parallel in the moving direction of the cleaning member. In the cleaning apparatus in any one of Claims 1 thru | or 4,
The radius of curvature of the pressing surface of the pressing member that is convexly curved in the moving direction of the cleaning member is such that the pressing amount of the pressing member and the printing are such that the pressing surface follows the bending shape of the printing mask. A cleaning device that is set according to the tension of a mask. The cleaning device according to any one of claims 1 to 5,
The cleaning device, wherein the pressing surface of the pressing member is curved in a convex shape in a direction intersecting the moving direction of the cleaning member. The cleaning device according to claim 6.
The radius of curvature of the pressing surface of the pressing member that is convexly curved in the direction intersecting the moving direction of the cleaning member is that the pressing member is pressed so that the pressing surface follows the bending shape of the printing mask. The cleaning device is set according to the amount and the tension of the printing mask. The cleaning device according to any one of claims 1 to 7,
The cleaning apparatus according to claim 1, wherein the sheet-like cleaning member is a fabric cloth for dust-free clothes in a clean room. The cleaning device according to any one of claims 1 to 8,
A cleaning device, wherein a surface portion of the pressing member having the pressing surface is formed of a rigid material. The cleaning device according to any one of claims 1 to 9,
Rotation drive means is provided for rotating the support roller so as to rotate the cleaning member when the cleaning member and the pressing member are moved along the surface to be cleaned of the printing mask. Cleaning device to do. The cleaning device according to any one of claims 1 to 9,
While the cleaning member and the pressing member are not moved along the surface to be cleaned of the printing mask, the cleaning member is rotated until the unused surface of the cleaning member faces the printing mask during the cleaning standby. A cleaning device comprising a rotation driving means for rotating the support roller. The cleaning device according to any one of claims 1 to 11,
A cleaning device comprising means for reciprocating the cleaning member along a surface to be cleaned of the printing mask in a direction intersecting with the moving direction of the cleaning member. A printing mask on which a plurality of openings are formed is set on a printing object, the printing mask is filled with a printing substance, and then the printing mask and the printing object are separated from each other, thereby printing the printing mask. A printing apparatus for printing the printing material on a surface to be printed of an object,
13. A printing apparatus using the cleaning apparatus according to claim 1 as a cleaning apparatus for cleaning a surface of the printing mask facing the object to be printed.

Images