Screen printing mask

Abstract

To intend to make it possible to form a printing pattern on a printing target with high accuracy and to improve durability of a mask, by suppressing elongation and shrinkage of a mask due to tensile stress and compression stress generated on a mask due to sliding resistance of a squeegee.SOLUTION: A screen printing mask comprises lower layer 2 having a group of pattern openings 3 and an upper layer 1 having a group of adjustment openings 4 corresponding to the pattern openings 3, wherein an upper surface of the upper layer 1 is a squeegee surface 6 on which a squeegee S is slid, a friction reducing section 13 in which a recess is formed on the squeegee surface 6 is provided, and a depth dimension of the recess in the friction reducing section 13 is formed as a thickness dimension of the lower layer 2.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] This invention is a method for fine printing of internal electrodes of ceramic capacitors and multilayer chip inductors. Screen printing masks used to form patterns by screen printing . [Background technology]

[0002] This type of screen printing mask is disclosed in, for example, Patent Document 1 previously proposed by the present applicant. The screen printing metal mask (mask) described in Patent Document 1 is a group of patterns. A mask plate (lower layer) with turn openings and cut mark openings, and a pattern opening and cut mark openings are and a squeegee plate (upper layer) having a group of adjustment openings corresponding to the squeegee mark openings. The squeegee plate and the mask plate are each made of metal. The squeegee surface is the surface that comes into contact with the surface of the squeegee. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-127126 A Summary of the Invention [Problem to be solved by the invention]

[0004] During printing, the squeegee moves in one direction with the tip of the squeegee pressed against the squeegee surface. While the squeegee is moving, the squeegee tip is moved toward the moving direction of the squeegee. The mask on the upper side is subjected to tensile stress, while the mask on the lower side in the direction of the squeegee movement is subjected to In the mask of Patent Document 1, the squeegee surface, i.e., the squeegee plate, is subjected to compressive stress. The top surface of the plate is flat except for a group of adjustment holes and cut mark holes. Therefore, the tip of the squeegee, which makes line contact with the squeegee surface, is almost completely in the length direction. The squeegee surface and the squeegee tip are in contact with each other while the squeegee is moving. The sliding resistance caused by friction is large. If the sliding resistance of the squeegee is large, the friction acts on the mask accordingly. The tensile and compressive stresses caused by the mask also increase, causing the mask to expand and contract, resulting in pattern opening. If the mouth is deformed, it is not possible to obtain a print pattern with the correct shape. There is also a risk that metal fatigue due to shrinkage will reduce the durability of the mask.

[0005] The present invention is directed to a method for preventing the generation of tensile and compressive stresses in a mask caused by the sliding resistance of a squeegee. This suppresses the expansion and contraction of the mask, enabling the printing pattern to be formed on the printing target with high precision. Another object is to improve the durability of the mask. [Means for solving the problem]

[0006] The screen printing mask of the present invention comprises a lower layer 2 having a group of pattern openings 3 and a pattern and an upper layer 1 having a group of adjustment openings 4 corresponding to the openings 3. The upper surface of the upper layer 1 is The squeegee surface 6 is formed with a recess. The friction reducing portion 13 is provided.

[0007] The friction reducing portion 13 is recessed on the squeegee surface 6 so as to coincide with the position where the adjustment opening 4 is formed. The recess 15 is formed by reducing the surface area.

[0008] The friction reducing portion 13 is a recessed surface area reducing portion formed on the squeegee surface 6, avoiding the position where the adjustment opening 4 is formed. It is composed of grooves 17.

[0009] The upper layer 1 is made of metal, and the lower layer 2 is made of resin.

[0010] The upper layer 1 and the lower layer 2 are integrally formed by one metal layer 40 . Effect of the Invention

[0011] As in the screen printing mask according to the present invention, the squeegee surface 6 has a friction member formed with depressions. When the lightening portion 13 is provided, the upper surface of the upper layer 1 constituting the squeegee surface 6 becomes an uneven surface, The length (area) of the tip of the squeegee S that contacts the squeegee surface 6 is reduced by the friction reducing portion 13. This allows most of the squeegee tip to be in contact with the squeegee surface. Compared to conventional masks, the friction between the tip of the squeegee S and the squeegee surface 6 is reduced, reducing the sliding resistance. This allows the mask to be moved in a straight line, so that the tensile and compressive stresses that occur in the mask when the squeegee S moves can be reduced. The stress can be reduced, and the print pattern can be formed on the print target with higher accuracy. The durability of the mask can also be improved.

[0012] The friction reducing portion 13 is recessed on the squeegee surface 6 so as to coincide with the position where the adjustment opening 4 is formed. When the squeegee surface 6 of the upper layer 1 is configured with a surface-reducing recess 15, the surface-reducing recess 15 is recessed and formed on the squeegee surface 6 of the upper layer 1. This simple structure can reduce friction. In comparison, the mask can be made lighter by the amount of the surface-reducing recess 15. Since the material for forming the upper layer 1 can be reduced, the manufacturing cost of the mask can be reduced.

[0013] The friction reducing portion 13 is a recessed surface area reducing portion formed on the squeegee surface 6, avoiding the position where the adjustment opening 4 is formed. When the squeegee surface 6 of the upper layer 1 is formed with the grooves 17, the grooves 17 can be simply recessed and formed in the squeegee surface 6 of the upper layer 1. It is possible to reduce friction with a simple structure. In addition, compared to conventional masks, the surface area is reduced. The weight of the mask can be reduced by the amount of the groove 17, and the material forming the upper layer 1 can be reduced by the amount of the groove 17. This reduces the manufacturing cost of the mask.

[0014] When the upper layer 1 is made of metal and the lower layer 2 is made of resin, the squeegee plate (upper layer) and Compared to conventional masks in which both the mask plate (lower layer) and the mask plate (lower layer) are made of metal, the weight of the lower layer 2 can be reduced. This allows the mask to be lighter. When the mask is attached to the mask support, the center of the mask can be prevented from bending downward due to its own weight. Therefore, deformation of the group of pattern openings 3 caused by the curvature of the mask can be prevented, and high accuracy of printing can be achieved. In addition, a printing method in which a mask is moved over a fixed printing target is also available. In the clean printing device, the load on the device is reduced by the reduced inertia caused by the mask movement. This can contribute to higher positioning accuracy and shorter printing cycles. Cut.

[0015] When the upper layer 1 and the lower layer 2 are integrally formed by one metal layer 40, the upper layer 1 and the lower layer 2 are Compared to forming two layers, such as metal and metal or metal and resin, there is little peeling between the two layers 1 and 2. This can prevent the mask from being damaged. [Brief description of the drawings]

[0016] [Figure 1] 1 is a vertical sectional side view of a screen printing mask according to a first embodiment of the present invention. [Diagram 2]1 is an overall plan view of a screen printing mask according to a first embodiment, and an enlarged view of a pattern opening and an adjustment opening. [Diagram 3] FIG. 2 is an explanatory diagram showing a primary electroforming step in the method for producing a screen printing mask according to the first embodiment. [Figure 4] FIG. 3 is an explanatory diagram showing a secondary electroforming step in the method for producing a screen printing mask according to the first embodiment. [Diagram 5] 4 is an explanatory diagram showing a resin layer forming step in the method for producing a screen printing mask according to Example 1. FIG. [Figure 6] FIG. 11 is a vertical sectional side view of a screen printing mask according to a second embodiment of the present invention. [Figure 7] FIG. 11 is an explanatory diagram showing a primary electroforming step in the method for producing a screen printing mask according to the second embodiment. [Figure 8] FIG. 11 is an explanatory diagram showing a secondary electroforming step in the method for producing a screen printing mask according to the second embodiment. [Figure 9] 10 is an explanatory view showing a resin layer forming step in the method for producing a screen printing mask according to Example 2. FIG. [Figure 10] FIG. 11 is a vertical sectional side view of a screen printing mask according to a third embodiment of the present invention. [Figure 11] FIG. 11 is an explanatory diagram showing a dummy forming step in the method for producing a screen printing mask according to the third embodiment. [Figure 12] FIG. 11 is an explanatory diagram showing a mask forming step in the method for producing a screen printing mask according to the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] (Example 1) FIG. 1 to FIG. 5 show a screen printing mask according to the present invention (hereinafter, simply referred to as a printing mask). In the present invention, the terms front, back, left, right, top and bottom refer to the same as those in FIG. Also follow the crossed arrows shown in Figure 2 and the indications of front, back, left, right, up and down written near each arrow. The dimensions such as thickness and width in the drawings of the following examples do not represent the actual state. Each is shown diagrammatically.

[0018] The printing mask is a multi-layer ceramic capacitor applied to the surface of the ceramic film to be printed. It is used to print and form the internal electrodes that make up the capacitor by screen printing. The printing mask is formed in a square shape with a side of 250 mm, and the mask is divided into four quadrants. When the substrate is divided into quadrants, a pattern forming area M for printing an electrode pattern is defined in each quadrant. is partitioned, and further, the pattern forming region M is surrounded by a screen printing Printing cut marks that are used when cutting the printed object into a specified shape during the process The cut mark forming area C is partitioned. The printing mask is a single mask or a mask with four peripheries. With a frame fixed to the edge, the mask is attached to a mask fixing portion of a screen printing device.

[0019] As shown in Figure 1, the printing mask is made up of an upper layer 1 made of metal and a lower layer 2 made of synthetic resin (resin). The lower layer 2 has a group of pattern openings 3. The upper layer 2 is provided with a group of adjustment openings 4 corresponding to the pattern openings 3. The outer shape of the adjustment opening 4 is the same as the opening shape of the pattern opening 3 or It may also be formed to be slightly smaller than the opening shape.

[0020] As shown in FIG. 2, the pattern opening 3 formed in the lower layer 2 has a rectangular shape that is long from left to right. The pattern forming regions M are arranged in a matrix. The adjustment opening 4 formed in the upper layer 1 above the opening 3 has a lattice-shaped adjustment rib 5 inside. The adjustment opening 4 has an outer shape similar to that of the pattern opening 3. The adjustment rib 5 is formed to be slightly larger than the opening shape. It is provided to adjust the amount of printing paste supplied.

[0021] Although not shown in the figure, the cut mark forming area C has a long and narrow rectangular shape formed on the lower layer 2. A cut mark opening is formed, and a cover is formed on the upper layer 1 above the cut mark opening. The adjustment opening is formed with a lattice-shaped adjustment rib inside. The cut mark opening is formed into a mesh-like opening, and the outer shape of the cut mark opening is The opening shape is slightly larger than that of the cut mark opening. The outer shape of the opening is the same as the opening shape of the cut mark opening, or It can also be formed slightly smaller than the shape. The opening shape in the mark formation area C may be made different.

[0022] The upper surface of the upper layer 1 constitutes a squeegee surface 6, and during printing, the printing material placed on the squeegee surface 6 is By squeegeeing the paste with the squeegee S, the pattern opening 3 and the cutter The print paste is filled into the openings, and an electrode pattern that matches the pattern openings 3 is printed on the surface to be printed. A printing layer is formed with a cut pattern that matches the cut mark openings. The squeegee S is moved from the front to the rear of the printing mask with its tip in contact with the squeegee surface 6. The "printing paste" mentioned here is solder paste, This concept includes thin solder, liquid solder, conductive ink, etc. The dimensions of the Keysi S, such as thickness and width, are also shown in a reduced schematic form.

[0023] The upper layer 1 of this embodiment is made up of a first metal layer 11 on the upper side, which is relatively thin, and a second metal layer 12 on the lower side, which is relatively thick. The squeegee surface 6 is formed by laminating a large second metal layer 12 on the lower side. The friction reducing portion 13 that reduces the sliding friction between the squeegee S and the squeegee surface 6 is formed as a recess. The adjustment opening 4 is formed in the second metal layer 12, and the first metal layer 11 has a corresponding adjustment opening 4. The through hole 14 is formed around the outer shape of the adjustment opening 4. The through hole 14 and the upper surface of the second metal layer 12 contact the squeegee surface 6. A surface-reducing recess 15 is formed. The adjustment opening 4 is opened at the bottom surface of the surface-reducing recess 15.

[0024] By providing a surface reduction recess 15 corresponding to the adjustment opening 4, the area of ​​the squeegee surface 6 is reduced The recess 15 reduces the friction between the squeegee S and the squeegee surface 6. The friction reduction portion 13 is formed by the surface reduction recess 15 formed in each adjustment opening 4. The squeegee surface 6 in the groove forming region M is in the shape of a lattice frame. The first metal layer 11 enters the alignment opening 4 through the portion 15 and fills the pattern opening 3. The thickness of the first metal layer 11 is set to 2 μm, and the thickness of the second metal layer 12 is set to 16 μm. The thickness of the upper layer 1 is 18 μm. The thickness of the lower layer 2 made of resin is set to 3 μm. The total thickness of the printing mask is 21 μm. A surface-reducing recess 15 may be provided corresponding to the opening.

[0025] As described above, the friction reducing portion 13 is arranged on the squeegee surface so as to coincide with the position where the adjustment opening 4 is formed. Since the squeegee surface 6 of the upper layer 1 is formed with a surface-reducing recess 15, The friction reduction effect can be achieved by simply forming a recess in the mass. In comparison with the conventional mask, the weight of the mask can be reduced by the area of ​​the surface-reducing recess 15. Since the material for forming the upper layer 1 can be reduced by the amount of 5, the manufacturing cost of the mask can be reduced. do.

[0026] An example of a method for manufacturing a printing mask according to this embodiment is shown in FIG. 3 to FIG. 5. The primary electroforming process shown in (a) to (d), the secondary electroforming process shown in FIG. 4(a) to (d), and the secondary electroforming process shown in FIG. The resin layer is formed through the steps of forming a resin layer shown in (a) to (c). As shown in FIG. 3(a), a conductive flat plate-shaped electroforming mold 20 made of stainless steel is provided on the surface thereof. A negative type first photoresist layer 21 is formed. Next, the first photoresist layer 21 is When a first pattern film 22 (photomask) is attached to the top, the stacked structure shown in FIG. A layered body can be obtained.

[0027] Next, the inside of the oven of the ultraviolet irradiation device equipped with the ultraviolet lamp 23 is heated to the oven temperature during the exposure operation. After the preheating is completed, the laminate obtained above is placed in the furnace of the ultraviolet irradiation device, and the laminate is After the layered body is allowed to acclimate to the temperature inside the furnace, it is irradiated with ultraviolet light from an ultraviolet lamp 23, The first photoresist layer 21 is exposed through the first pattern film 22. The body is removed, the first pattern film 22 is removed from the first photoresist layer 21, and the second The unexposed portions of the photoresist layer 21 are dissolved and removed (developed) to obtain the photoresist layer 21 shown in FIG. As shown, a primary pattern resist 24 is formed on an electroforming mold 20. The aperture 24 is an aperture for adjusting the pattern aperture 3 and the cut mark aperture. The resist pattern is made up of a resist body corresponding to the portion.

[0028] Next, as shown in FIG. 3(c), the electroforming matrix not covered with the primary pattern resist 24 is By performing electroforming (plating) on ​​the surface of the mold 20, the height of the primary pattern resist 24 is A primary electroforming layer 25 that will become the second metal layer 12 is formed within the range. After the primary electroforming layer 25 is formed, The surfaces of the primary pattern resist 24 and the primary electroforming layer 25 are polished and smoothed, as shown in FIG. The result will be in state d).

[0029] In the secondary electroforming process, as shown in FIG. 4(a), a primary pattern resist 24 and A negative type second photoresist layer 28 is then formed on the surface of the primary electroforming layer 25. 2. A second pattern film 29 (photomask) is adhered to the photoresist layer 28. The second pattern film 29 has light transmitting holes formed therein corresponding to the through holes 14. Then, ultraviolet light is irradiated from the ultraviolet lamp 23 to cause the second frame to be exposed through the second pattern film 29. The photoresist layer 28 is exposed to light. After exposure, a second pattern film is formed from the second photoresist layer 28. The film 29 is removed, and the unexposed portions of the second photoresist layer 28 are dissolved and removed (developed). As a result, as shown in FIG. 4(b), the primary pattern resist 24 and the primary electroforming layer 25 A secondary pattern resist 30 is formed on the through hole 14. The resist layer is made of a material corresponding to the resist pattern.

[0030] Next, as shown in FIG. 4(c), the primary electrode that is not covered with the secondary pattern resist 30 is By subjecting the surface of the casting layer 25 to electroforming (plating), the secondary pattern resist 30 is highly A secondary electroformed layer 31 that will become the first metal layer 11 is formed within the range of the thickness. After the secondary electroformed layer 31 is formed When the electroforming matrix 20 is removed, the mask precursor shown in FIG. Before removing the electroforming mold 20, the surfaces of the secondary pattern resist 30 and the secondary electroforming layer 31 are The surface may be polished to make it smooth. Polishing may be performed in each step as necessary. do.

[0031] In the resin layer forming process, the inverted mask precursor body is temporarily fixed on a surface plate, as shown in FIG. As shown in FIG. 1, a photocurable emulsion resin (photocurable resin) 34 is poured onto the surface of the mask precursor. The surface of the primary electroforming layer 25 and the primary pattern resist 24 are then bonded to each other by utilizing the fluidity of the emulsion. The emulsion resin 34 is evenly applied to the surface. After the emulsion resin 34 is evenly applied, the emulsion resin 34 is A third pattern film 35 (photomask) is placed on the third pattern film 35. The film 35 can be disposed in close contact with the emulsion resin 34, and can be attached to the emulsion resin 34 with a small gap therebetween. The ultraviolet lamp 23 then irradiates the ultraviolet ray. The emulsion resin 34 is exposed to light through the third pattern film 35 and hardened. After hardening, the third pattern film 29 is removed from the emulsion resin 34, and the unhardened part of the emulsion resin 34 is By removing the oxidized portion, as shown in FIG. 5(b), the primary pattern resist 24 and Then, a lower layer 2 having an opening corresponding to the pattern opening 3 is formed on the primary electroforming layer 25 as a mask precursor. Finally, the primary and secondary pattern resists 24 and 30 are removed and then inverted again. As a result, the completed printing mask shown in FIG. 5(c) can be obtained.

[0032] Since the lower layer 2 in this embodiment is made of a photocurable resin, it is possible to form the lower layer 2 by a photolithography method. The lower layer 2 having a complex planar shape can be easily formed with high accuracy. The photocurable resin is made of photocurable emulsion resin 34, so the emulsion-based The resulting fluidity of the emulsion resin 34 allows it to be easily applied so that the surface of the emulsion resin 34 becomes smooth. The curable emulsion resin 34 is not only curable in response to ultraviolet light, but also in response to visible light. The lower layer 2 is not limited to the photocurable emulsion resin 34 used in this embodiment, The lower layer 2 may be formed of a liquid resist or a sheet resist. Thermosetting resins have better chemical resistance and durability than photocurable resins. Excellent solubility, suitable for printing where printing paste containing acid, alkali, or solvent is used. It can be used in a printing environment. In addition, it can be washed with acid, alkali, or other chemicals after use. It is also advantageous in that cleaning agents containing solvents or the like can be used.

[0033] As described above, the surface-reducing recess 15 is formed on the squeegee surface 6, but the adjustment opening 4 is formed. When the surface is set as the reference surface, the reference surface, i.e., the second metal It can be seen that the first metal layer 11 forms a lattice frame-like protrusion protruding upward from the upper surface of the layer 12. At this time, the upper surface of the lattice frame-shaped protrusions formed of the first metal layer 11 is in contact with the squeegee surface 6. The protrusions are arranged so as to surround the pattern forming area M and / or the cut mark forming area C. The projections are not limited to a lattice frame shape or a continuous shape, but may be discontinuous. It may be in the form of a dotted line.

[0034] (Example 2) FIGS. 6 to 9 show a screen printing mask (hereinafter, simply referred to as a printing mask) according to the present invention. In this embodiment, the structure of the friction reduction portion 13 is different from that in the first embodiment. Specifically, the upper layer 1 is formed by stacking a first metal layer 11 on the upper side and a second metal layer 12 on the lower side. The squeegee surface 6 is formed with a squeegee S and a squeegee surface 6. The friction reducing portion 13 is recessed between the adjacent adjustment openings 4 on the first metal layer 11. The slit 16 is formed in the upper surface of the second metal layer 12, and the squeegee surface is formed by the slit 16 and the upper surface of the second metal layer 12. The surface reduction groove 17 is formed in the adjustment opening 4. An adjustment opening 4 is formed in the squeegee surface 6 adjacent to 17 .

[0035] The area of ​​the squeegee surface 6 is reduced by the area of ​​the surface reduction groove 17, which is formed by the squeegee S and the The friction reducing portion 13 is formed to reduce friction with the keyway surface 6. Due to the surface-reducing grooves 17 formed in a lattice frame shape, the squeegee surface 6 in the pattern forming region M is The squeegee surface 6, which is a rectangular frame that surrounds the adjustment opening 4, is arranged in a matrix. The thickness of the first metal layer 11 is set to 2 μm, and the thickness of the second metal layer 12 is set to 16 μm. The thickness of the upper layer 1 made of a metal layer is 18 μm. The thickness of the lower layer made of a resin layer is 3 The printing mask is set to a total thickness of 21 μm. A surface-reducing recess 15 can be provided to correspond to the adjustment opening for the opening. The rest is the same as in the first embodiment. Therefore, the same members are designated by the same reference numerals and their explanations are omitted. I feel so sad.

[0036] As described above, the friction reducing portion 13 is recessed into the squeegee surface 6 so as to avoid the position where the adjustment opening 4 is formed. Since the squeegee surface 6 of the upper layer 1 is configured with a surface reduction groove 17 formed thereon, the surface reduction groove 17 is recessed and formed in the squeegee surface 6 of the upper layer 1. This simple structure can reduce friction. Compared to conventional masks, The weight of the mask can be reduced by the area of ​​the surface-reducing groove 17. Since the amount of material required for forming the mask can be reduced, the manufacturing cost of the mask can be reduced.

[0037] An example of a method for manufacturing the printing mask according to this embodiment is shown in FIG. 7 to FIG. 9. The primary electroforming process shown in (a) to (d), the secondary electroforming process shown in FIG. 8(a) to (d), and the process shown in FIG. The resin layer is formed through the steps of forming a resin layer shown in (a) to (c). As shown in FIG. 7(a), a conductive flat plate-shaped electroforming mold 20 made of stainless steel is provided on the surface thereof. A negative type first photoresist layer 21 is formed. Next, the first photoresist layer 21 is When a first pattern film 22 (photomask) is attached to the top, the stacked structure shown in FIG. A layered body can be obtained.

[0038] Next, the inside of the oven of the ultraviolet irradiation device equipped with the ultraviolet lamp 23 is heated to the oven temperature during the exposure operation. After the preheating is completed, the laminate obtained above is placed in the furnace of the ultraviolet irradiation device, and the laminate is After the layered body is allowed to acclimate to the temperature inside the furnace, it is irradiated with ultraviolet light from an ultraviolet lamp 23, The first photoresist layer 21 is exposed through the first pattern film 22. The body is removed, the first pattern film 22 is removed from the first photoresist layer 21, and the second The unexposed portions of the photoresist layer 21 are dissolved and removed (developed) to obtain the photoresist layer 21 shown in FIG. As shown, a primary pattern resist 24 is formed on an electroforming mold 20. The aperture 24 is an aperture for adjusting the pattern aperture 3 and the cut mark aperture. The resist pattern is made up of a resist body corresponding to the portion.

[0039] Next, as shown in FIG. 7(c), the electroforming matrix not covered with the primary pattern resist 24 is By performing electroforming (plating) on ​​the surface of the mold 20, the height of the primary pattern resist 24 is A primary electroforming layer 25 that will become the second metal layer 12 is formed within the range. After the primary electroforming layer 25 is formed, The surfaces of the primary pattern resist 24 and the primary electroforming layer 25 are polished and smoothed, as shown in FIG. The result will be in state d).

[0040] In the secondary electroforming process, as shown in FIG. 8(a), a primary pattern resist 24 and A negative type second photoresist layer 28 is then formed on the surface of the primary electroforming layer 25. 2. A second pattern film 29 (photomask) is adhered to the photoresist layer 28. The second pattern film 29 has an adjustment opening 4 for the pattern opening 3 and a cut mark opening. A light transmitting hole corresponding to the opening of the mouth adjustment opening and the slit 16 is formed. Then, ultraviolet light is irradiated from the ultraviolet lamp 23 to form the second photoresist through the second pattern film 29. After exposure, a second pattern filter is formed from the second photoresist layer 28. The film 29 is then removed, and the unexposed portions of the second photoresist layer 28 are dissolved and removed (developed). As a result, as shown in FIG. 8(b), the primary pattern resist 24 and the primary electroforming layer 25 A secondary pattern resist 30 is formed on the second pattern resist 30. The secondary pattern resist 30 has a pattern opening. 3 and the resist body 3 corresponding to the opening of the adjustment opening 4 for the cut mark opening 3, and a resist body 30b corresponding to the slit 16.

[0041] Next, as shown in FIG. 8(c), the primary electrode that is not covered with the secondary pattern resist 30 is By subjecting the surface of the casting layer 25 to electroforming (plating), the secondary pattern resist 30 is highly A secondary electroformed layer 31 that will become the first metal layer 11 is formed within the range of the thickness. After the secondary electroformed layer 31 is formed When the electroforming matrix 20 is removed, the mask precursor shown in FIG. Before removing the electroforming mold 20, the surfaces of the secondary pattern resist 30 and the secondary electroforming layer 31 are may be polished to make it smooth.

[0042] In the resin layer forming process, the inverted mask precursor body is temporarily fixed on a surface plate, and then, as shown in FIG. As shown in FIG. 1, a photocurable emulsion resin (photocurable resin) 34 is poured onto the surface of the mask precursor. The surface of the primary electroforming layer 25 and the primary pattern resist 24 are then bonded to each other by utilizing the fluidity of the emulsion. The emulsion resin 34 is evenly applied to the surface. After the emulsion resin 34 is evenly applied, the emulsion resin 34 is A third pattern film 35 (photomask) is placed on the third pattern film 35. The film 35 can be disposed in close contact with the emulsion resin 34, and can be attached to the emulsion resin 34 with a small gap therebetween. The ultraviolet lamp 23 then irradiates the ultraviolet ray. The emulsion resin 34 is exposed to light through the third pattern film 35 and hardened. After hardening, the third pattern film 29 is removed from the emulsion resin 34, and the unhardened part of the emulsion resin 34 is By removing the oxidized portion, the primary pattern resist 24 and the Then, a lower layer 2 having an opening corresponding to the pattern opening 3 is formed on the primary electroforming layer 25 as a mask precursor. Finally, the primary and secondary pattern resists 24 and 30 are removed to form the The finished printing mask shown in FIG. 9(c) can be obtained.

[0043] As in the above-mentioned respective embodiments, when the lower layer 2 is made of a resin layer, the flow property derived from the emulsion resin 34 is reduced. By utilizing this property, the emulsion resin 34 can be applied thinly and uniformly. The lower layer 2 made of the above can be formed thin and uniform in thickness, so that the mass This improves the printing accuracy of the mask, and also makes it possible to make the mask thinner and lighter. Since it can be applied by utilizing the fluidity derived from the resin, it is easy to form a thin and uniform lower layer. There are some advantages to doing so.

[0044] In the above-mentioned embodiments, the lower layer 2 is formed from a photocurable emulsion resin 34. The sheet may be adhesively fixed to the lower surface of the upper layer 1 to form the lower layer 2. In this case, the adhesive The resin sheet before application is subjected to laser processing to cut out and form the pattern opening 3, and then The upper layer 1 is bonded and fixed to the resin sheet. Alternatively, a resin sheet is bonded and fixed to the upper layer 1, and then laser processing is performed. A printing mask can be obtained by performing a process to remove the pattern opening 3 by sublimation. The resin layer forming step may be performed by the following method: A plastic resin plate is placed on the surface of the mask precursor body that is temporarily fixed on a surface plate, and the softened thermoplastic resin is The resin plate is pressed flat against the mask front body. This causes a part of the resin plate to fit into the receiving recess 16A. The thermoplastic resin plate is cooled and hardened again, and then the The unnecessary parts are removed by sublimation using laser processing, or melted and removed using etching processing to create a pattern. The lower layer 2 is formed by forming the opening 3 .

[0045] The upper layer 1 is made of metal and the lower layer 2 is made of synthetic resin. The weight of the lower layer 2 can be reduced compared to conventional masks in which both the mask plate (lower layer) and the mask plate are made of metal. The mask can be made lighter. When the mask is worn on the face, it prevents the center of the mask from bending downward due to its own weight, so This prevents deformation of the group of pattern openings 3 caused by the curvature of the disk, thereby achieving high printing accuracy. In addition, a screen printer is used to print by moving a mask over a fixed printing target. In the printing device, the load on the device is reduced by the smaller inertia caused by the mask movement. This contributes to higher positioning accuracy and shorter printing cycles.

[0046] In the manufacturing method in each of the above embodiments, the primary pattern resist 24 and the secondary pattern The resin layer forming step was carried out while leaving the resist 30, but the primary pattern resist 24 It is also possible to carry out the resin layer forming step after removing the secondary pattern resist 30. In this case, when removing the primary pattern resist 24 and the secondary pattern resist 30, This prevents the lower layer 2 (photocurable resin 34) from falling off and being removed together. The printing mask of the embodiment uses an electroforming mold in which a recess corresponding to the first metal layer 11 is formed. In the next electroforming step, a primary electroforming layer that becomes the first metal layer 11 is formed in the recess, and a second metal layer 12 is formed. After forming the secondary electroforming layer, the lower layer 2 is formed with the photocurable resin 34 in the resin layer forming process. In this case, the electroforming mold is removed after the resin layer forming step (the formation of the lower layer 2). may be also possible.

[0047] (Example 3) FIG. 10 to FIG. 12 show a screen printing mask according to the present invention (hereinafter, simply referred to as The printing mask of this embodiment is a third embodiment of the printing mask. The printing mask of this embodiment has an upper layer 1 and a lower layer 2. The difference from the second embodiment is that it is formed of one mask metal layer (metal layer) 40. The layer 40 has a thickness portion that forms the group of adjustment openings 4 and constitutes the upper layer 1, and the remaining group of patterns The thickness portion that forms the opening 3 constitutes the lower layer 2. The squeegee surface 6 is provided with a hole 4 to avoid the adjustment opening 4. The surface-reducing grooves 17 constituting the friction-reducing portion 13 are formed so as to reduce the surface area of ​​the friction-reducing portion 13 .

[0048] An example of a method for manufacturing a printing mask according to this embodiment is shown in Fig. 11 and Fig. 12. 11(a) to (d) show the dummy forming process, and FIG. 12(a) to (d) show the mask forming process. In the dummy formation process, as shown in FIG. A negative type photoresist is applied to the surface of a flat stainless steel electroforming mold 42 having electrical conductivity. Then, a pattern film 44 (photoresist layer 43) is formed on the photoresist layer 43. By closely adhering a second mask (not shown) to the first layer, the laminate shown in FIG. 11(a) can be obtained.

[0049] Next, the inside of the oven of the ultraviolet irradiation device equipped with the ultraviolet lamp 45 is heated to the oven temperature during the exposure operation. After the preheating is completed, the laminate obtained above is placed in the furnace of the ultraviolet irradiation device, and the laminate is After the layered body is allowed to acclimate to the temperature inside the furnace, it is irradiated with ultraviolet light from an ultraviolet lamp 45, The photoresist layer 43 is exposed through the pattern film 44. After exposure, the laminate is taken out. Then, the pattern film 44 is removed from the photoresist layer 43, and the photoresist layer 4 The unexposed portion of 3 is dissolved and removed (developed) to obtain the electroformed matrix as shown in FIG. 11(b). A pattern resist 46 is formed on the mold 42. The pattern resist 46 is formed in such a manner that the surface area reduction groove 17 is The resist is made of a material having a corresponding resist.

[0050] Next, as shown in FIG. 11(c), the electroforming mold not covered with the pattern resist 46 is By subjecting the surface of 42 to electroforming (plating) processing, the height range of the pattern resist 46 is After the dummy electroforming layer 47 is formed, the pattern resist 46 and The surface of the dummy electroformed layer 47 is polished and smoothed, and the pattern resist 46 is removed. This results in the state shown in FIG. 11(d).

[0051] In the mask forming process, as shown in FIG. 12(a), an electroforming mold 42 and a dummy electrode are A negative type mask photoresist layer 49 is formed on the surface of the casting layer 47. Then, a mask A mask pattern film 50 (photomask) is adhered to the photoresist layer 49. The mask pattern film 50 has adjustment openings 4 for the pattern openings 3 and cut marks. A light transmitting hole corresponding to the opening of the opening adjustment opening is formed. Next, the ultraviolet lamp 4 5, the mask photoresist layer is irradiated with ultraviolet light through the mask pattern film 50. After exposure, the mask photoresist layer 49 is exposed to a mask pattern film 50. The unexposed portions of the mask photoresist layer 49 are then dissolved and removed (developed). As shown in FIG. 12(b), a mask pattern resist 51 is formed on the electroforming matrix 42. The mask pattern resist 51 has an adjustment opening 4 for the pattern opening 3 and a cut marker. The resist layer is formed in a region corresponding to the opening of the alignment opening for the mask opening.

[0052] Next, as shown in FIG. 12(c), the electrode that is not covered with the mask pattern resist 51 is The surfaces of the casting mold 42 and the dummy electroformed layer 47 are subjected to electroforming (plating) treatment to form a mass. A mask electroforming layer 52 that becomes the mask metal layer 40 is formed within the range of the height of the pattern resist 51. At this time, since the electroforming thickness in the electroforming process is constant, the dummy electroforming layer 47 The portion protrudes upward from the electroforming matrix 42 portion. This provides the pattern opening 3. After the mask electroforming layer 52 is formed, a mask pattern register is formed. The plate 51 is removed, and then the electroforming matrix 42 and the dummy electroforming layer 47 are removed. As shown in FIG. The finished print mask shown in FIG.

[0053] According to this embodiment, the upper layer 1 and the lower layer 2 are formed by one mask metal layer 40. Compared with the case where the upper layer 1 and the lower layer 2 are formed as two layers such as metal and metal or metal and resin, The risk of peeling between the two layers and damage to the printing mask can be avoided. Compared to the printing mask of 2, the printing mask can be manufactured without the resin layer formation process. In the above manufacturing process, the electroforming mold 42 The dummy electroforming layer 47 is firmly integrated with the starting material 42 so that it cannot be separated. Since the mask forming process can be performed as a single mask, the dummy forming process can be omitted and the manufacturing process of the printing mask can be performed. The structure is simplified, and the printing mask can be manufactured more inexpensively. In order to strengthen the adhesion with the electroformed layer 47, an adhesion treatment is performed before forming the dummy electroformed layer 47. In addition, it is preferable to perform a pre-plating treatment (pre-plating treatment) to improve the peelability between the dummy electroformed layer 47 and the metal layer 40. In order to prevent this, it is advisable to perform a peeling treatment on at least the surface of the dummy electroformed layer 47. The electroformed layer 47 and the metal layer 40 are not separated, and the dummy electroformed layer 47 and the metal layer 40 are integrated. In addition, the printing mask of this embodiment has a recess corresponding to the lower layer 2. After forming a mask pattern resist 51 using the electroforming mold, a mask metal layer 4 This can also be achieved by forming a mask electroforming layer 52 that becomes 0.

[0054] As described above, in the screen printing mask according to each of the above-mentioned embodiments, the squeegee surface 6 is Since the friction reducing portion 13 is recessed in the direction of the squeegee surface 6, the upper layer 1 constituting the squeegee surface 6 The length of the tip of the squeegee S that contacts the squeegee surface 6 is set to the length of the friction reducing portion 13. This allows most of the squeegee tip to come into contact with the squeegee surface. Compared to the conventional mask, the friction between the tip of the squeegee S and the squeegee surface 6 is reduced, Since the dynamic resistance can be reduced, the tensile stress generated in the mask when the squeegee S moves It is also possible to suppress compressive stress and form the print pattern on the print target with higher accuracy. In addition, the durability of the mask can be improved.

[0055] The surface-reducing recess 15 and the surface-reducing groove 17 in each of the above-mentioned embodiments are formed as recesses and grooves without steps. However, it can be formed with multi-stage recesses and grooves. The dimensions of each part are the same as those shown in the above embodiment. The printing mask of the present invention is not limited to the above. The mask structure of the printing mask is not limited to that used for printing electrodes. It can also be used as a mask for solder ball mounting, or a mask for solder ball adsorption. It is possible. [Explanation of symbols]

[0056] 1 upper layer 2 Lower layer 3 Pattern opening 4 Adjustment aperture 6 Squeegee surface 13 Friction reduction section 15. Reduced surface area 17 Reducing surface groove 40 Metal layer (mask metal layer) S squeegee

Claims

1. A lower layer (2) having a group of pattern openings (3) and an upper layer (1) having a group of adjustment openings (4) corresponding to the pattern openings (3), The upper surface of the upper layer (1) is a squeegee surface (6) on which the squeegee (S) slides. A friction reducing portion (13) formed by a recess is provided on the squeegee surface (6), A screen printing mask characterized in that the thickness of the lower layer (2) is constant with the depth of the recesses in the friction reducing portions (13) formed as recesses.

2. 2. The screen printing mask according to claim 1, wherein the friction reducing portion (13) is constituted by a surface-reducing recess (15) recessed into the squeegee surface (6) so as to coincide with the formation position of the adjustment opening (4).

3. 2. The screen printing mask according to claim 1, wherein the friction reducing portion (13) is constituted by a surface reduction groove (17) recessed into the squeegee surface (6) to avoid the position where the adjustment opening (4) is formed.

4. 4. The screen printing mask according to claim 1, wherein the upper layer (1) is made of metal and the lower layer (2) is made of resin.

5. 4. The screen printing mask according to claim 1, wherein the upper layer (1) and the lower layer (2) are integrally formed from a single metal layer (40).

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