JP2008213215A - Metal mask and metal mask screen plate employing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metal mask, in which no waste of adhesion material such as solder or the like at printing develops and the labor for recovering the adhesion material not used in printing can be reduced or eliminated, and a metal mask screen plate. <P>SOLUTION: This metal mask is made of a metal plate 2, in the region X1 of which patterned holes 4 are provided and is employed as a substance for executing printing on the surface of a material to be printed by being brought into contact with or arranged near the material to be printed and, after the adhesion material is supplied to its surface opposite to the side of the material to be printed, by rubbing the surface with a squeegee 6 having a near rectilinear contact part normal to the contact part (or towards Y-direction) for thrusting out the adhesion material through the patterned holes 4. In addition, a plurality of projected parts 8, on the side of each of which one side face 8a facing to the upstream of the moving direction of the squeegee 6 and being tilted so as to approach nearer at its downstream side than at its upstream side to the center line B are provided in the metal mask at the region locating on both the sides or the left and right sides of the center line B parallel to the moving direction (or the Y-direction) of the squeegee 6 as a reference. Further, the metal mask screen plate is constituted of the metal mask. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a metal mask that is a plate material for screen printing that enables high-precision pattern printing, and a metal mask screen plate using the same.

  2. Description of the Related Art Conventionally, for example, screen printing that enables high-precision pattern printing has been adopted when applying and forming solder paste (cream solder), conductor paste, etc. on a printed wiring board for mounting various electronic components and the like. . In particular, when high-precision pattern printing is desired, a screen printing plate such as a metal mask is used as a plate material for screen printing.

FIG. 15 is a plan view from the squeegee surface side for explaining the operation of screen printing using a metal mask. FIG. 15 shows a state in which solder, printing ink, or other adhering material 112 is supplied to the squeegee surface of the metal mask 110 and the squeegee 106 is on standby (before starting the printing operation).
The metal mask 110 is formed by providing holes 104 having a desired pattern in a predetermined region X ′ of a metal plate 102 made of stainless steel or the like. The squeegee 106 is a plate-like member and rubs the adhering material 112 into the hole 104.

  In screen printing using a metal mask, the surface of the metal mask 110 on the substrate side (the surface facing downward in FIG. 15) is brought into contact with or slightly separated from the surface of the substrate (not shown). And move in the direction of the arrow Y while pressing the squeegee 106 or the like from the surface (squeegee surface) opposite to the substrate side to the surface on the substrate side. Printing is performed on the surface of the substrate by extruding the adhering material. This printing method is particularly suitable when the substrate is a flat plate.

  If the adhering material 112 supplied to the flat squeegee surface is merely rubbed with the squeegee 106, the adhering material 112 is not smoothly rubbed into the hole 104, and there is a concern that the printed image may be lost or the adhering material 112 may accumulate. . Occurrence of missing print images and accumulation of adhering materials during printing impedes the formation of a uniform pattern image. Therefore, these improvements are always desired in reproducing high-definition patterns.

  FIG. 16 is a plan view showing an initial state of the printing operation in which the squeegee 106 is moved halfway from the state of FIG. The adhering material 112 is rubbed into the hole 104 at the site through which the squeegee 106 has passed. Further, the adhering material 112 that has been rubbed and moved by the squeegee 106 spreads in the longitudinal direction of the squeegee 106, and was initially supplied to the range corresponding to the region X ′ that is the printing region (the state in FIG. 15). However, this range is exceeded as indicated by reference numerals 112a and 112b.

  Further, FIG. 17 is a plan view showing a state in the latter half of the printing operation in which the squeegee 106 is moved. As the squeegee 106 moves, the adhering material 112 spreads further in the longitudinal direction, and eventually overflows from the left and right ends of the squeegee 106 as indicated by reference numerals 112a 'and 112b'.

  As described above, the adhering material spreads in the longitudinal direction of the squeegee 106 and exceeds the range of the region X which is the printing region (reference numerals 112a, 112b, 112a ′ and 112b ′. Hereinafter, simply referred to as “112a etc.”). ) Is wasted without being used for printing, leading to waste of resources. In order to save resources, if this is recovered and used again, the operation of recovering the adhering material 112a and the like spread over a wide range becomes complicated, resulting in a decrease in workability. Further, when the adhesion material 112 or the like exceeds the range of the region X ′, the adhesion material 112 in the range of the region X ′ is insufficient, which may cause a printing defect.

JP-A-10-129140

Therefore, the present invention is a metal mask suitable for forming a high-definition pattern such as applying a solder paste to a printed wiring board, a semiconductor substrate, etc. It is an object of the present invention to provide a metal mask and a metal mask screen plate using the metal mask that can reduce or eliminate the labor of collecting the adhered material that has not been used for printing without waste of materials.
Another object of the present invention is to provide a metal mask with improved printability and a metal mask screen plate using the same, which can print a uniform pattern image with no omission or accumulation of print images. To do.

The above object is achieved by the present invention described below. That is, the metal mask of the present invention is provided with a desired pattern of holes in one or more regions of the metal plate,
The contact material is placed in contact with or close to the surface of the printing material, and the adhesion material is supplied to the surface opposite to the printing material side, and then the surface is rubbed in a direction perpendicular to the contact portion with a squeegee whose contact portion is substantially linear. Is a metal mask for printing in a pattern on the surface of the substrate by extruding the pattern from the hole,
With respect to the center line B parallel to the moving direction of the squeegee in the region, both sides of the center line B face the upstream side of the moving direction of the squeegee, on the left and right sides, and with respect to the center line B A convex portion (hereinafter referred to as an “inward-alignment working surface”) that is inclined so as to be closer to the downstream side than the upstream side (hereinafter referred to as “inward-alignment action surface”) Characterized in that it is provided with a plurality of "protrusions".

  According to the metal mask of the present invention, after supplying the adhesion material to the surface (squeegee surface) opposite to the substrate side, the adhesion material spreading in the longitudinal direction of the squeegee when the surface is moved and rubbed with the squeegee, When it comes into contact with the inward acting surface of the convex portion, it is moved in the direction of the center line B due to the inclination of the inward acting surface, and is pushed back to a range corresponding to a predetermined region provided with a pattern-like hole. Therefore, the supplied adhering material is effectively used for printing, and there is no waste, and the labor for collection can be reduced or eliminated. Moreover, since the adhering material does not spread unnecessarily and is effectively used for printing, the amount of adhering material to be supplied can be reduced.

  When a printing operation is performed in any direction by reciprocating the squeegee, it is preferable that the convex portion has an inwardly acting surface corresponding to each moving direction of the squeegee. By configuring in this way, even when the squeegee is moved in any direction, the supplied adhering material is moved toward the center line B direction, and the supplied adhering material is effectively used for printing, and there is no waste. The work effort can be reduced or eliminated, and the amount of the adhering material supplied can be reduced, and the efficiency of the printing work can be improved. It can be a triangular shape with one side as two sides.

The planar shape of the convex portion is not particularly limited as long as it has a line segment (side) having one or two inwardly acting surfaces, but a linear shape having a small contact area with the squeegee. It is preferable to make the contact surface flat or to prevent uneven wear and cracks or chipping at the tip of the squeegee due to a load on the contact portion of the squeegee.
The height of the convex portion from the metal plate cannot be generally specified depending on various conditions. However, in order to reduce the load on the squeegee and suppress the influence on the printed image, the height is 0.1 to 50 μm. It is preferable to be within the range.

  Even if the convex portions are arranged one by one on both ends of the straight line A with which the squeegee comes into contact, the function of the present invention is naturally exerted at the disposed positions, and the effects of the present invention can be expected. However, in order to bring the adhering material inward over the entire area in the moving direction of the squeegee so that it can be effectively used for printing, it is preferable to provide a plurality of both on both ends of the straight line A.

  A second convex portion having an arbitrary planar shape whose height from the metal plate is equal to or less than that of the inwardly convex portion is provided in a portion other than the portion where the pattern-like hole is provided inside and outside the region. It is preferable. By providing the second convex portion, this acts as a barrier for particles contained in the adhesion material such as solder, for example, to improve rolling characteristics (rolling property) and promote the movement of the adhesion material. As a result, the followability of the metal mask to the squeegee surface is enhanced, and the adhering material is leveled and supplied to the pattern-like holes, so that a uniform pattern image free from omission and accumulation can be printed.

  Even if the adhering material is a liquid, it is presumed that particles such as adhering substances in the liquid, as well as particle-like behavior due to intermolecular forces in the liquid, are expressed, and rolling by the second convex portion The effect of homogenizing the pattern image based on the improvement of the performance or the equivalent action is exhibited. Therefore, hereinafter, the description will be made using the expression “improving rolling property” including the case where the particle-like substance is not included in the adhered substance.

  The metal mask of the present invention can be made into a metal mask screen plate that can be used for normal screen printing by fixing the outer periphery of the metal mask to a plate frame via a belt-like elastic stretch band. At this time, the elastic stretch band is preferably a ridge generally used as a mesh (crease) in a metal mask screen plate.

According to the present invention, by providing an inwardly convex portion having an appropriate shape at an appropriate location, the adhering material is brought to the printing area during printing, and solder, printing ink, and other adhering materials are effectively used for printing. Therefore, it is possible to provide a metal mask and a metal mask screen plate using the same that can reduce or eliminate the labor for collecting the adhering material that has not been used for printing without waste.
In addition, according to the present invention, by providing the second convex portion at a more appropriate location, a metal mask with improved printability capable of printing a uniform pattern image with no omission or accumulation of the print image, and the same The used metal mask screen plate can be provided.

[Metal Mask Embodiment]
First, the metal mask of the present invention will be described in detail with reference to the drawings, with some embodiments and modifications thereof.

<First Embodiment>
FIG. 1 is a plan view from the squeegee surface side of a metal mask according to a first embodiment which is an exemplary aspect of the present invention. In FIG. 1, the squeegee 6 is also shown with the metal mask 10 of this embodiment.

The metal mask 10 is provided with a desired pattern-shaped hole 4 in a predetermined region X1 of a metal plate 2 made of stainless steel or the like, and a total of twelve triangular protrusions 8 arranged side by side outside the region X1. It is made. The convex portion 8 has an inwardly acting surface 8a on one side of the triangle, and corresponds to the inwardly convex portion.
In FIG. 1, a center line B (a center line parallel to the moving direction of the squeegee 6 in the region X1) B that equally bisects the metal mask 10 in the traveling direction of the squeegee 6 moving in the arrow Y direction during printing is drawn. It is.

  FIG. 2 is a perspective view of the paper surface of FIG. However, in FIG. 2, for ease of explanation, the illustration of the hole 4 provided in the metal mask 10 is omitted, and only the region X1 where the pattern exists is shown. Similarly, illustration of the squeegee 6 is omitted, and only a straight line A where the squeegee 6 contacts the metal mask 10 is shown. Furthermore, in FIG. 2, only the left and right three convex portions 8 are shown, and the illustration of the back is also omitted.

Only the left one in FIG. 2, that is, only the convex portion 8 indicated by the arrow C is extracted, and the configuration of the inward convex portion in the present invention will be described below with reference to FIGS. However, the right convex part 8 also exhibits the same effect and exhibits the same effect except that it is bilaterally symmetric.
FIG. 3 is an enlarged perspective view in which only the convex portion 8 indicated by the arrow C in FIG. 2 is extracted. FIG. 4 is an enlarged plan view in which only the relationship between the convex portion 8 and the center line B indicated by the arrow C in FIG. 2 is extracted.

  As can be seen from FIGS. 2 to 4, the convex portion 8 has a predetermined thickness (height) and thus has a side surface, and one of the three side surfaces is an inwardly acting surface 8 a. This inward working surface 8a faces upstream in the moving direction of the squeegee 6 and approaches the center line B closer to the downstream side (8a-1) than the upstream side (8a-2) (line segment). b> A side surface inclined by line segment a) (see FIG. 4). By inclining the inwardly acting surface 8a in this way, the spread of the adhering material in the longitudinal direction of the squeegee 6 during printing is suppressed (hereinafter, this effect may be referred to as “inwardly acting”). Used for printing. The operation and effect will be described in detail later.

FIG. 5 is a schematic explanatory diagram for explaining the relationship between the inward acting surface 8a and the center line B in the convex portion 8 indicated by the arrow C in FIG. The angle θ formed by the inwardly acting surface 8a and the center line B is hereinafter referred to as an “inwardly acting angle”.
There is no limitation on the degree of inclination of the inwardly acting surface 8a, and the present invention only needs to satisfy “line segment b> line segment a” (0 ° <inner approach operating angle θ <90 °) shown in FIG. The effect of this is expressed and the effect is achieved. However, if this inclination is too large (the value of the inward movement θ is large), the effect of suppressing the spread of the adhering material in the longitudinal direction of the squeegee 6 becomes small and too small (the value of the inward movement θ is small). A long path is required to bring the adhering material in the direction of the center line B, which is not preferable.

  Specifically, the lower limit of the value of the inward movement θ is preferably 5 ° or more, more preferably 20 ° or more, and further preferably 45 ° or more. On the other hand, the upper limit of the value of the inward movement θ is preferably 85 ° or less, more preferably 80 ° or less, and further preferably 70 ° or less.

  FIG. 6A shows an enlarged cross-sectional view of the inwardly acting surface 8a in the convex portion 8 and its peripheral portion. As indicated by reference sign D, the boundary between the contact surface 8b with the squeegee and the inwardly acting surface 8a is in a state of being angled, effectively damming the adhering material such as solder, and the center line B side It is a shape that can lead to.

  However, it may be in a so-called chamfered state with rounded corners as indicated by reference numeral D 'in FIG. By chamfering in this way, the load on the tip of the squeegee 6 can be reduced, and uneven wear and cracks or chipping can be suppressed. In the case of chamfering, the effects of chamfering and the decrease in the damming effect of the adhering material should be weighed and chamfered to an appropriate degree.

  Next, according to the printing operation by the metal mask of this embodiment, the effect | action and effect of this invention are demonstrated using FIGS. 7-9. 7 to 9 are plan views from the squeegee surface side for explaining the operation of the screen printing using the metal mask of FIG. 1, FIG. 7 is a state before starting the printing operation, FIG. Is a middle stage of the printing operation, and FIG. 9 is a state after a little time has elapsed from the state of FIG.

  First, the metal mask 10 is placed and fixed on the surface to be printed of a printed material such as a printed circuit board so that the surface on the printed material side is in contact, and the squeegee 6 is placed at the position before printing (see FIG. (The printed material is not shown.) Then, as shown in FIG. 7, the adhesive material 12 such as solder is supplied to the moving direction Y side of the squeegee 6.

  Next, the squeegee 6 is moved in the direction of the arrow Y while pressing the squeegee surface of the metal mask 10 to rub the adhering material 12 into the holes 4 and through this, it is pushed out to the substrate. At this time, the adhering material 12 rubbed and moved by the squeegee 6 spreads in the longitudinal direction of the squeegee 6 (both ends of the straight line A in FIG. 2) and initially (state of FIG. 7). Is supplied to the range corresponding to the area X1 which is the print area, and exceeds the range as indicated by reference numerals 12a and 12b. When the sticking materials 12a and 12b in the protruding state hit the inwardly acting surface 8a of the convex portion 8, the inwardly acting effect works, and is pulled back to the center line B side as shown in FIG.

  This inward action does not mean that all of the protruding parts 12a and 12b of the adhering material 12 moving together with the squeegee 6 abut against the inwardly acting surface 8a and be brought to a position corresponding to the area A. The protruding parts 12a and 12b Even if a part or most of 12b rides up and moves on the flat surface portion 8b of the convex portion 8, the effect of the present invention is obtained if the action of the protruding portions 12a and 12b moves toward the center line B and works. Is demonstrated.

  In addition, the adhesion material 12 rides on the convex portion 8 in this way, so that the rolling property of the adhesion material 12 is improved, and the movement of the adhesion material 12 in the region and the vicinity thereof is promoted to follow the surface of the metal plate 22. There is also an effect of increasing the nature. Therefore, even when the adhesion material 12 is a collection of fine particles such as solder, there is no problem even if the height of the convex portion 8 is smaller than the solder particles, damage to the squeegee 6, printability, etc. From this, an appropriate height of the convex portion 8 is selected.

  As described above, according to the metal mask of the present embodiment, when the adhesive material 12 that spreads in the longitudinal direction of the squeegee 6 during printing contacts the inwardly acting surface 8a of the convex portion 8, the inwardly acting surface 8a is inclined. Is pushed in the direction of the center line B and pushed back in the direction of the range corresponding to the region X1 in which the pattern-like hole 4 is provided. Therefore, the supplied adhering material 12 is effectively used for printing, and the labor of the collection work can be reduced or eliminated. Moreover, since the adhering material 12 does not spread unnecessarily and is effectively used for printing, the amount of the adhering material 12 to be supplied can be reduced to an amount close to the necessary minimum.

In the present invention, the planar shape of the convex portion is not limited to a triangular shape like the convex portion 8 of the present embodiment, and there is no particular limitation as long as it has the above-described inwardly acting surface.
FIG. 10 is a plan view showing a modification of the planar shape of the convex portion. In each of FIGS. 10A to 10C, the lower side is the upstream direction of the squeegee, and the right side is the center line B side of the region where the pattern-shaped hole is provided.

A convex portion 8-1 shown in FIG. 10A has a linear shape, and one of the side surfaces is an inwardly acting surface 8-1a. This shape is preferable because it has a small contact area with the squeegee at the time of printing and can suppress uneven wear and cracks or chipping due to a load on the squeegee tip.
The convex portion 8-2 shown in FIG. 10B has a rectangular shape, and one of the long sides is an inwardly acting surface 8-2a. Further, the convex portion 8-3 shown in FIG. 10C has a trapezoidal shape, and the hypotenuse is an inwardly acting surface 8-3a.

When the planar shape has a certain area, such as the planar shape shown in FIGS. 10B and 10C or a triangular shape as in this embodiment, the contact surface with the squeegee (reference numeral in FIG. 3). It is preferable that 8b) be flat because uneven wear and cracks or chipping due to a load on the squeegee tip can be suppressed. Of course, even if the shape is a straight line such as the convex portion 8-1 shown in FIG. 6A, it is desirable to make the contact surface flat when a certain area is recognized in the flat shape.
As the planar shape other than the linear shape, as shown in the present embodiment, it is a triangular shape (with an inwardly acting surface as one side) in which a plurality of convex portions can be arranged efficiently. preferable.

  The thickness of the protrusion (height of the metal mask from the metal plate) is not uniquely determined, but the size (area, thickness) and material of the metal mask, the hole pattern (size and pitch), If the shape is selected appropriately depending on the shape of the projection (various shapes other than 8, 28, 38, and 48), the presence or absence of chamfering, the type of adhering material (material, properties, etc.), the strength of the squeegee, the moving speed of the squeegee Good. For example, when the adhesion material is solder, the thickness of the convex portion is determined to some extent from the solder particle size. The particle size of the solder is approximately 1 μm to 50 μm, and the appropriate particle size range varies depending on the printing application.

Specifically, the thickness of the convex portion is selected from a range of 0.1 μm to 50 μm, and preferably within a range of 0.2 μm to 20 μm.
Further, in order to reduce the load on the squeegee and suppress the influence on the printed image, it is preferably in the range of 0.3 to 10 μm, more preferably in the range of 0.4 μm to 5 μm. More preferably, it is in the range of 0.5 μm to 5 μm. .

As the number of convex portions, in the present embodiment, a total of 12 left and right 6 pieces are arranged, but this number is not limited, and an appropriate number may be selected from the behavior of the attached material to be used. Further, if only one each on the right and left sides is provided at the important point, the inward movement effect is effectively achieved, and an excellent effect peculiar to the present invention can be expected. Furthermore, even if it is arranged only on one side of the left or right, or even if it is arranged at a position that is not the optimum condition, at least the inward action by the inward action surface of the arranged convex part is exerted, so it is unique to the present invention. Can be expected.
Of course, in order to express the inward movement more effectively, it is desirable to provide a plurality of convex portions on the left and right.

  In the present embodiment, the arrangement of the convex portions is bilaterally symmetric, but of course it is not limited thereto, and it may be considered in a staggered or random manner. The spacing between adjacent convex portions does not need to be constant as in the present embodiment. For example, the spacing is gradually designed so that the spacing gradually decreases from upstream to downstream in the moving direction of the squeegee 6. be able to.

<Second Embodiment>
FIG. 11 is a plan view from the squeegee surface side of the metal mask 20 of the second embodiment, which is an exemplary aspect of the present invention. In FIG. 11, as in FIG. 1, a squeegee 26 is also shown together with the metal mask 20 of the present embodiment.

  In the present embodiment, the pattern of the hole 24 provided in the metal plate 22 and its region X2 are the same as the pattern of the hole 4 provided in the metal plate 2 of the metal mask 10 of the first embodiment and its region X1. Yes, and the same squeegee 26 is used. In the present embodiment, the shape of the inward protruding portion is different from the protruding portion 8 of the first embodiment, and the base is parallel to the end side of the metal plate 22 as shown by the protruding portion 28 in FIG. Isosceles triangle shape.

  In this embodiment, as in the first embodiment, the squeegee 26 stands by at the left position L before the start of the printing operation. Then, the squeegee 26 moves in the arrow Y direction at the time of printing, and reaches the position R at the end of printing. After the end of the first printing, the metal mask 20 is placed and fixed on the printing target surface of another substrate (not shown), and then the next printing operation is performed by moving from the position R in the direction of the arrow Y ′. The That is, the moving direction of the squeegee 26 is two directions (reciprocal (Y, Y ′)).

  In the present embodiment, the convex portion 28 forms an inward acting surface with respect to the squeegee 26 that moves in the arrow Y direction, as one of the side surfaces 28a. Further, another side surface 28a 'constitutes an inward acting surface for the squeegee 26 moving in the arrow Y' direction. That is, the convex portion 28 has inwardly acting surfaces 28a and 28a ′ corresponding to the moving directions Y and Y ′ of the squeegee 26, and is an isosceles triangle having these as isosceles and the other one as a base. is there.

  According to the metal mask of the present embodiment, even when the squeegee 26 is reciprocated and a printing operation is performed, due to the action of the inwardly acting surfaces 28a and 28a ′ corresponding to the moving directions Y and Y ′ of the squeegee 26. The supplied adhering material is moved in the direction of the center line B, the supplied adhering material is effectively used for printing, and there is no waste, the labor of collection work is reduced or eliminated, and the amount of adhering material supplied is reduced. In addition, the efficiency of the printing work can be improved.

  The degree of inclination of the inwardly acting surfaces 28a and 28a 'in the convex portion 28 (inwardly acting angle θ: see FIG. 5) is as described in the first embodiment. It should be noted that the inward working angle θ of each of the two inward acting surfaces 28a and 28a ′ may be the same or different.

  The thickness of the convex portion 28 (height from the metal plate of the metal mask) is as described in the first embodiment. Further, as the number of convex portions, in the present embodiment, a total of ten left and right five are arranged. However, in the present invention, this number is not limited and can be appropriately set according to the first embodiment. As described in. Since these (the inward working angle θ, the thickness of the convex portion, and the number of convex portions) are the same in the following embodiments, the description in the section of each embodiment is omitted.

  The planar shape of the convex portion for realizing the functions and effects in the present embodiment is not limited to the isosceles triangle shape as in the convex portion 28 of the present embodiment, and each moving direction Y, squeegee 26, There are no particular restrictions as long as two inward working surfaces corresponding to Y ′ are provided. For example, it may be a polygonal shape such as a quadrangle or pentagon with two sides being inwardly acting surfaces, or any other indefinite shape, or a triangular shape that does not form isosceles, with different inwardly acting angles θ of the respective inwardly acting surfaces. It doesn't matter.

<Third Embodiment>
FIG. 12 is a plan view from the squeegee surface side of the metal mask 20 according to the third embodiment which is an exemplary aspect of the present invention. In FIG. 12, as in FIG. 1, the squeegee 36 is also shown together with the metal mask 30 of the present embodiment.

In the present embodiment, the pattern of the holes 34 provided in the metal plate 32 and the region X3 thereof, as well as the arrangement and shape of the convex portions 38, are provided in the metal plate 2 of the metal mask 10 of the first embodiment. It is the same as the pattern of the hole 4, its region X1, and the convex portion 8, and the squeegee 36 is also the same. This embodiment is different from the first embodiment in that, in addition to the configuration of the first embodiment, a second convex portion 39 is provided inside and outside the region X3.
The second protrusions 39 are basically rectangular in shape, and are regularly arranged over the inside and outside of the region X3. However, the part with the hole 34 has a shape lacking only that part, and the lacked part is perforated.

  The thickness (height from the metal plate) of the second convex portion 39 is the same as or lower than that of the convex portion 38 that is an inwardly convex portion. As long as the respective functions of the inward convex portion and the second convex portion are exhibited, the thicknesses of the both may be different. Specifically, the difference in thickness between the two is preferably within ± 20% on average, but the difference may be wider. Specifically, the thickness of the convex portion 39 is preferably in the range of 0.1 μm to 5 μm, and more preferably in the range of 0.5 μm to 5 μm.

  According to the present embodiment, by providing the second convex portion 39, this serves as a barrier for particles contained in the adhesion material such as solder, for example, so that rolling stagnation is given and rolling property (rolling property) is improved. Then, the movement of the adhering material is promoted, the followability of the metal mask 30 to the squeegee surface is enhanced, and the adhering material is leveled and supplied to the pattern-shaped holes 34 to print a uniform pattern image without any omission or accumulation. be able to.

  In particular, the convex portion 38, which is an inward convex portion characteristic of the present invention, has an effect of bringing the adhering material that is going to spread in the longitudinal direction toward the center line B direction, and at the same time, also exhibits an effect of improving the rolling property at the location. The rolling property of the adhering material is improved over the entire longitudinal direction of the moving squeegee 36, the movement of the adhering material is promoted, and the followability of the metal mask to the squeegee surface is enhanced. Since the adhering material is brought inward by the projections 38 and supplied to the region X3 with a high rolling property as a whole, the adhering material is supplied to the pattern-shaped holes 34 in a uniform manner, so that there is no omission or accumulation. Images can be printed.

  The shape of the second convex portion 39 is rectangular in the present embodiment, but is not limited to this, and is not limited to this, but is a polygonal shape such as a square shape, a triangular shape, or a pentagonal shape, a circular shape, an elliptical shape, or the like. Various shapes including indefinite shapes can be employed. However, it is preferable to have a surface facing the squeegee 36 in parallel when a high rolling performance improvement effect is required.

  Further, as the second convex portion, a surface having the same function as the inwardly acting surface such as the same or similar shape as the inwardly convex portion (the movement of the squeegee having an inclination with respect to the center line B) The shape may be provided with a surface facing upstream in the direction. In this case, however, it is desirable that the surface be inclined so as to be closer to the downstream side than the upstream side with respect to the center line B, as in the case of the inward projection. By arranging the second protrusions in this way, the movement of the adhering material that spreads in the longitudinal direction of the squeegee is limited as it moves with the squeegee if there is no inward protrusion and no second protrusion. Then, a force that gathers in the direction of the center line B acts, and in combination with the rolling property improving effect by these convex portions, the adhering material is leveled and supplied, and a uniform pattern image without omission or accumulation is printed. be able to.

  As the arrangement of the second protrusions, the second protrusions 39 of the present embodiment are mainly arranged in a zigzag pattern on the entire surface of the region A, but they may be arranged vertically and horizontally or randomly. Also good. Further, the density may be varied according to the pattern of the holes 34, or more may be arranged outside the region X.

  As described above, in the present embodiment, the second convex portions 39 are regularly arranged ignoring the pattern of the holes 34, and the hole 34 portions are perforated as they are. It is also possible to select a part where no is located and place the second convex part. Note that even if the thickness of a part of the edge of the hole 34 is increased by the amount of the second convex portion 39 having a height substantially equal to that of the inwardly convex portion, the convexity to such an extent as to cause the inward effect and rolling property. If it is the height of the part, there is no concern of affecting the printability.

<Fourth Embodiment>
FIG. 13 is a plan view from the squeegee surface side of the metal mask 20 according to the fourth embodiment, which is an exemplary aspect of the present invention. In FIG. 13, as in FIG. 1, a squeegee 46 is also shown together with the metal mask 40 of the present embodiment.

In the present embodiment, each of the four regions Xa, Xb, Xc, and Xd of the metal plate 42 is provided with a pattern-like hole, and an inward protrusion corresponding to each of these regions is provided. In FIG. 13, the center line Ba-b in the region Xa and the region Xb and the center line Bc-d in the region Xc and the region Xd are drawn in parallel with the moving direction of the squeegee 6 (arrow Y direction). It is.
Since it is common to the four regions Xa, Xb, Xc, and Xd, the region Xa will be described. In FIG. 13 as well, the reference numerals are attached to only the region Xa together with the lead lines, but of course the same applies to the other three regions.

As can be seen from FIG. 13, the center of the squeegee 46 in the region Xa (the direction of the arrow Y) is parallel to the center line Ba-b on the left and right sides of the squeegee 46 at locations other than the region Xa. One surface (inward working surface 48a) that faces upstream (left side in FIG. 13) in the moving direction (arrow Y direction) and is inclined to approach the center line Ba-b on the downstream side rather than the upstream side. 6 on the left and right sides are provided.
The convex portion 48 is similarly provided in the regions Xb, Xc, and Xd.

  As described above, when a plurality of regions Xa, Xb, Xc, and Xd provided with pattern-like holes 44 are included in one metal mask 40 (four in this embodiment), each region is included in each region. On the other hand, by providing the convex portion 48 functioning as an inwardly convex portion, an inward action occurs in each region, and the outer periphery of the metal mask 40 or its periphery, as well as between the regions Xa-Xc and between the regions Xb-Xd. It is pushed back to a range corresponding to the regions Xa, Xb, Xc, Xd from the place where the hole 44 does not exist. Therefore, the supplied adhering material is used for printing extremely effectively, and there is no waste, and the labor for the collection can be reduced or eliminated. In addition, since the adhering material does not spread unnecessarily and is effectively used for printing, the amount of the adhering material to be supplied can be reduced to an amount close to the necessary minimum.

  The number of the “regions” is four in the present embodiment. However, the number of “regions” is not limited to this in the present invention, and may be more, or may be three or less. Absent. In addition, what kind of area is the area referred to in the present invention is an aggregate of pattern-like holes and has a certain range, and is based on the center line B parallel to the moving direction of the squeegee. Any region can be discussed as a single region as long as it is possible to provide inward protrusions on the left and right sides of the region other than the region.

For example, in FIG. 13, it is assumed that one “region” according to the present invention is configured by four regions Xa, Xb, Xc, and Xd, and the metal mask is the same as in FIG. 1 according to the first embodiment. It is possible to provide the inwardly convex portion only in the vicinity of the long side of 40. Of course, as in this embodiment, it is preferable that the “regions” are finely divided and captured, and the inwardly protruding portions are provided corresponding to these “regions”, so that the supplied adhering material is less wasteful. .
In the present embodiment, the configuration in which the same pattern-shaped holes 44 are provided in the four regions Xa, Xb, Xc, and Xd is illustrated, but the pattern of the holes provided in the plurality of “regions” is different. The size of each region may be different.

The metal mask of the present invention has been described with reference to preferred embodiments and modifications. However, the present invention is not limited to the above embodiments, and those skilled in the art will be able to configure the present invention based on known knowledge. Changes and improvements can be added.
For example, the inwardly convex portion having the shape described in the second embodiment is incorporated into the configuration of the metal mask of the third or fourth embodiment to form a metal mask compatible with reciprocal printing, or the second described in the third embodiment. The configuration of each embodiment can be arbitrarily selected, for example, by incorporating convex portions into the configuration of the metal mask of Example 4 and using a metal mask having a plurality of “regions” to improve the rolling property of the adhesion material over the entire surface. Of course, the metal mask incorporated in the above is included in the scope of the present invention.

[Details of metal mask components]
Next, each element constituting the metal mask of the present invention will be described in detail.
(Metal plate)
In the present invention, the material of the metal plate of the metal mask is not particularly limited, and various metals that have been conventionally used as a metal mask material in a metal mask screen plate can be used without any problem. Specific examples include nickel, iron, copper, and alloys containing these metals. Among these, nickel and its alloys are preferable from the viewpoint of workability and economy.

In the present invention, the thickness of the metal plate is not particularly limited, but is preferably 5 μm or more and more preferably 10 μm or more in order to ensure a certain degree of durability. On the other hand, the upper limit of the thickness of the metal plate can be appropriately thick depending on the purpose, but in order to obtain a high-definition image, it is preferably 100 μm or less, and preferably 50 μm or less. More preferred.
In the present invention, the size of the metal plate depends on the area of the surface to be printed and is not particularly limited. In general, a rectangular plate having a side of 50 mm to 1000 mm is selected. Of course, the shape of the metal mask is not limited to a rectangle.

(Pattern hole (opening))
Since the pattern-like hole (opening) is a pattern to be printed with an adhesive material such as solder paste, there is no limitation on the size and shape, and a desired shape and size are appropriately selected. However, when solder paste is printed for the purpose of wiring or bump formation on a printed circuit board, the opening diameter corresponding to a circle is generally set to 15 μm or more in consideration of the particle size of the solder particles and the function of the printed circuit board. It is desirable.

(Convex)
The inwardly convex portions characteristic of the present invention are (1) a method of forming by integral molding with the metal plate, (2) a method of forming portions by removing portions other than the convex portion from the metal plate, (3 ) A method of forming a convex portion on a metal plate by plating or painting, and (4) a method of separately forming only an inwardly convex portion and affixing it to the metal plate.

(1) “Method of forming by integral molding with the metal plate”
In the case of integrally molding as a method for forming the inwardly protruding portion, a recess capable of forming the inwardly protruding portion is provided in advance in the mold for forming. For example, when a metal plate is formed by rolling, a recess capable of forming the inward protruding portion may be provided in advance on the final roll.

(2) “Method of removing a portion other than the convex portion from the metal plate to form the convex portion”
Examples of the method for removing the portion other than the inwardly protruding portion from the metal plate to form the inwardly protruding portion include two methods, a chemical removing method and a physical removing method. In the case of this method, the operation of forming the convex portion may be performed either before or after the pattern-like hole is drilled in the metal plate.

  The chemical method is a method of forming the inward protrusion by chemical etching. In other words, chemical etching is a method in which a portion where the inwardly protruding portion is formed on the squeegee surface of the metal plate is masked with a resist or the like, and a portion other than the portion is etched with an acid (etching solution) suitable for the material of the metal plate. This is a method of forming an inward projection by melting by etching. By adjusting the type and concentration of the etching solution, the etching time, etc., it is possible to easily form the inward protruding portion having a predetermined height (height from the metal plate), which is a preferable forming method. .

  The physical method is a method in which a part other than the part where the inwardly protruding portion is formed is physically scraped by shot blasting or other various types of polishing. When polishing, by masking the part where the inward convex part is formed, the part other than the part can be efficiently scraped to form the inward convex part, but the part where the inward convex part is formed It is also possible to use a method in which only the other part is shot. According to the physical method, the obtained squeegee surface is appropriately roughened, so that the rolling property of the adhesive material such as solder is improved, but it is difficult to form the inwardly convex portion having a dense shape.

(3) “Method of forming protrusions on metal plate by plating or painting”
In the method of forming the convex portion on the metal plate by plating or painting, the operation of forming the convex portion may be performed either before or after the pattern-like hole is drilled in the metal plate.
In the case of plating, either the same material as the metal plate or a different material can be used as the plating material, and may be selected according to the purpose and application. As a plating method, it is possible to adopt a general method without any particular limitation. However, in order to form a densely shaped inward projection, an electrolytic plating method, an electroless plating method, various vapor deposition methods are used. It is preferable to employ a precise plating method such as.

On the other hand, in the case of coating, it is desirable to form a coating film having a strength that can withstand rubbing with the squeegee. It is desirable to select a paint that can form a film.
In both cases of plating and painting, a portion other than the portion where the inwardly protruding portion is formed on the squeegee surface of the metal plate may be masked with a resist or the like, and then the plating or coating operation may be performed. As a result, plating or painting is performed on a portion other than the masked portion, and an inwardly protruding portion is formed.

(4) Method of separately producing only the inwardly convex portion and pasting it on the metal plate This method creates a so-called seal that becomes the inwardly convex portion and sticks this to the metal plate Is the method. Specifically, an appropriate adhesive may be applied to a sheet made of various resins, various metals, fiber cloths, nonwoven fabrics, ceramic materials, and the like, and bonded to the metal plate. It is desirable to form with the material and adhesive which have the intensity | strength which can be rubbed with a squeegee.

  For example, according to the above-described methods (1) and (2), the material of the inwardly convex portion characteristic of the present invention is inevitably the same material as that of the metal plate, and the above (3) and (4). There is no particular limitation on this method. Specific examples include various metals, resins, and ceramic materials. In the above (3), when the inward projection is formed by plating, it is preferable to select a material that has the strength to withstand the rubbing against the squeegee by fusing with the metal plate. Most preferably.

  On the other hand, the second convex portion can also be formed by the same method as the inwardly convex portion, and the same material can be selected. At this time, it may be formed by a method other than the method selected by the inward projection, or may be formed by the same method. Also, the material may be the same or different. When it is desired to make the heights of the two more uniform, it is desirable to form the inwardly projecting convex portion and the second convex portion at the same time using the same material and the same method.

[Metal mask screen version]
The metal mask of the present invention may be used after being fixed to a plate frame to form a metal mask screen plate. In a normal screen printing plate, soot is provided on the entire surface of the squeegee side by stretching it to the outer periphery of the metal mask and fixing it to the plate frame. However, if the metal mask of the present invention is stretched by a member corresponding to this “紗”, the action of the inwardly convex portion and the second convex portion characteristic of the present invention is spoiled. A belt-like elastic stretch band may be attached to the outer periphery (preferably on the squeegee surface side) of the metal mask of the present invention, and fixed to the plate frame through this.

  FIG. 14 is a plan view of a metal mask screen plate in which the metal mask according to the first embodiment, which is an example of the present invention, is fixed to a plate frame, as viewed from the squeegee surface side. An elastic stretch body 14 having a rectangular opening slightly smaller than the outer shape of the metal mask 10 is attached to the adhesive portion 18 near the outer periphery on the squeegee surface side in the metal mask 10 of the first embodiment. The squeegee surface is glued to reveal. Then, the outer periphery of the elastic stretch body 14 is fixed to the mold frame 16, and the metal mask 10 is stretched over the mold frame 16 via the elastic stretch body 14 (a state similar to a so-called “stretching”); It has become.

  Since such an elastic stretch band is a member having the same significance as that of a screen used in a normal screen printing plate on the outside of the metal mask (metal plate), conventionally, a mesh (mesh) of the metal mask screen plate is used. What has been used as a material can be used without problems. Specific examples include metal meshes such as stainless steel, aluminum, iron, copper, and alloys containing these metals, and resin meshes such as polyester (for example, Tetron (registered trademark)). Moreover, the thing which coat | covered the surface of these resin meshes with the said metal or alloy may be sufficient.

  However, since the collar that can be used as the elastic tension band in the present invention is not provided in the pattern-shaped hole formed in the metal mask, the thickness of the fiber and the density of the fiber (so-called “mesh”) are not affected. There is no limit. The fiber thickness and fiber density are completely arbitrary as long as it has a desired elastic force that can be stretched between the metal mask of the present invention and the plate frame with a tension suitable for printing. The value of Moreover, as long as it has the said desired elastic force, it will not be specifically limited to a collar, It is also possible to employ | adopt a conventionally well-known sheet-like or film-like member as said elastic stretch band. From the viewpoint of durability and cost, it is most convenient and preferable to use a heel as the elastic stretch band.

  Moreover, there is no restriction | limiting in particular as a usable plate frame, The thing conventionally used as a plate frame in a screen printing plate can be used without a problem. When fixed to the plate frame via the elastic stretch band (so-called “saddle tension”), sufficient tension is applied to the elastic stretch band, and it has sufficient shape retention when used for screen printing. If it is a thing, no restrictions will be imposed on its shape, structure, size, and material. As specific materials, various plastic materials may be used in addition to metal materials such as stainless steel, aluminum, iron, and copper.

  The fixing between the metal plate and the elastic stretch band and the fixation between the elastic stretch band and the plate frame are not particularly limited, and may be performed by a conventionally known general method. For example, examples of adhesion fixing methods include welding methods, adhesive methods, plating methods, ultrasonic welding methods, mechanical attachment methods such as attachment by pressing with screws or pressers, and the like. There is no problem even if it is done by any method.

  In the present invention, the plate frame is not an essential component, but in normal screen printing, it is often used while being stretched on the plate frame. However, the case where it can be used for screen printing in a state in which it does not have a plate frame such as that directly attached to a printing apparatus is also assumed, and even in such a case, the metal mask of the present invention can be suitably used.

It is a top view from the squeegee surface side of the metal mask of 1st Embodiment which is an exemplary aspect of this invention. It is the perspective view seen from the upper left in the paper surface of FIG. It is an expansion perspective view of the convex part shown by the arrow C in FIG. It is the enlarged plan view which extracted only the relationship between the convex part shown by the arrow C in FIG. 2, and the centerline B. FIG. 3 is a schematic explanatory diagram for explaining a relationship between an inward acting surface and a center line B in a convex portion indicated by an arrow C in FIG. 2. It is an expanded sectional view which shows the inward effect | action surface in a convex part, and its peripheral part, (a) shows the aspect of the convex part shown by the arrow C in FIG. 2, (a) shows the modification. It is a top view from the squeegee surface side for demonstrating the operation | movement about the screen printing using the metal mask of FIG. 1, and is the state before a printing operation start. It is a top view from the squeegee surface side for demonstrating the operation | movement about the screen printing using the metal mask of FIG. 1, and is a middle step of the printing operation. It is a top view from the squeegee surface side for explaining the operation | movement about the screen printing using the metal mask of FIG. 1, and is the state which time passed for a while from the state of FIG. It is a top view which shows the modification of the planar shape of a convex part. It is a top view from the squeegee surface side of the metal mask of 2nd Embodiment which is an exemplary aspect of this invention. It is a top view from the squeegee surface side of the metal mask of 3rd Embodiment which is an exemplary aspect of this invention. It is a top view from the squeegee surface side of the metal mask of 4th Embodiment which is an exemplary aspect of this invention. It is a top view from the squeegee surface side of the metal mask screen plate which fixed the metal mask of FIG. 1 to the plate frame. It is a top view from the squeegee surface side for demonstrating the operation | movement about the screen printing using the conventional metal mask, and is the state before a printing operation start. It is a top view from the squeegee surface side for demonstrating the operation | movement about the screen printing using the conventional metal mask, and is the state of a printing work initial stage. It is a top view from the squeegee surface side for demonstrating the operation | movement about the screen printing using the conventional metal mask, and is the state of the printing work late stage.

Explanation of symbols

2, 22, 32, 42, 102: Metal plates 4, 24, 34, 44, 104: Patterned holes 6, 26, 36, 46, 106: Squeegees 8, 28, 38, 48: Protrusions 10, 20 , 30, 40, 110: Metal mask 12, 112: Adhering material 14: Elastic tension body 16: Formwork 18: Adhesive part 39: Second convex part

Claims (10)

A desired pattern-shaped hole is provided in one or more regions of the metal plate,
The contact material is placed in contact with or close to the surface of the printing material, and the adhesion material is supplied to the surface opposite to the printing material side, and then the surface is rubbed in a direction perpendicular to the contact portion with a squeegee whose contact portion is substantially linear. Is a metal mask for printing in a pattern on the surface of the substrate by extruding the pattern from the hole,
With respect to the center line B parallel to the moving direction of the squeegee in the region, both sides of the center line B face the upstream side of the moving direction of the squeegee, on the left and right sides, and with respect to the center line B A metal mask comprising a plurality of protrusions having a side surface inclined so as to approach the downstream side rather than the upstream side. 2. The metal mask according to claim 1, wherein the movement direction of the squeegee is two directions of reciprocation, and the convex portion has the one surface corresponding to each movement direction. 3. The metal mask according to claim 2, wherein the planar shape of the convex portion is a triangular shape having two sides of the one surface. The metal mask according to claim 1, wherein a contact surface of the convex portion with the squeegee is planar. The metal mask according to claim 1, wherein the planar shape of the convex portion is a linear shape having the one surface as one side surface. The metal mask according to claim 1, wherein a height of the convex portion from the metal plate is in a range of 0.1 to 50 μm. The metal mask according to claim 1, wherein a plurality of the convex portions are provided on both the left and right sides of the center line B as a reference. A second convex part having an arbitrary planar shape whose height from the metal plate is equal to or less than the convex part is provided in a part other than the part where the pattern-like hole is provided inside and outside the region. A metal mask according to claim 1, wherein: A metal mask screen plate, wherein the outer periphery of the metal mask according to any one of claims 1 to 8 is fixed to a plate frame via a belt-like elastic stretch band. The metal mask screen plate according to claim 9, wherein the elastic stretch band is a ridge.

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