JP7329359B2 - screen printing mask - Google Patents

Description

TECHNICAL FIELD The present invention relates to a screen printing mask used for forming fine printed patterns such as internal electrodes of ceramic capacitors and multilayer chip inductors by screen printing. The present invention relates to a screen printing mask of laminated structure.

A screen printing mask of this type is disclosed, for example, in Patent Document 1. The mask described in Patent Document 1 is composed of an upper metal layer made of metal plating (electroforming) having a plurality of mesh patterns and a lower resin layer made of a photosensitive resin having a plurality of printed patterns. . The upper and lower surfaces of the metal layer are flat surfaces, and the resin layer is fixed to the lower surface of the metal layer.

JP 2008-162277 A

According to the mask in which the lower layer having the printed pattern is formed of a resin layer, as in Patent Document 1, the thickness can be made thinner and more uniform than when the lower layer is formed of a metal layer. Therefore, the printing accuracy of the mask is improved, and the thickness and weight of the entire mask can be reduced. However, in the mask of Patent Document 1, the resin layer is adhered and fixed to the lower surface of the flat metal layer only by the adhesive force derived from the photosensitive resin. Therefore, the pressing force of the squeegee acting on the mask during printing and the bending deformation of the mask due to the pressing force repeatedly act on the mask, so that the adhered portions of the upper and lower layers are separated and the two are separated, and the mask is damaged. There is a risk of

SUMMARY OF THE INVENTION An object of the present invention is to firmly adhere and fix an upper layer made of metal and a lower layer made of resin to prevent damage to a mask due to peeling of the upper and lower layers.

The screen printing mask of the present invention comprises a lower layer 2 made of resin having a group of pattern openings 3 and an upper layer 1 made of metal having a group of adjustment openings 4 corresponding to the pattern openings 3 . Between the upper layer 1 and the lower layer 2, there is provided an encroaching portion 13 in which the upper layer 1 partially intrudes into the lower layer 2, or an encroaching portion 13 in which the lower layer 2 partially intrudes into the upper layer 1. It is characterized by

The biting portion 13 is composed of a receiving recess 16 recessed between the adjacent adjustment openings 4 on the lower surface of the upper layer 1 and a biting projection 15 protruding from the upper surface of the lower layer 2 and biting into the receiving recess 16. ing.

The biting portion 13 is composed of a receiving recess 16 recessed in the upper surface of the lower layer 2 and a biting protrusion 15 projecting between the adjacent adjustment openings 4 on the lower surface of the upper layer 1 and biting into the receiving recess 16. ing.

A contact surface between the biting projection 15 and the receiving recess 16 at the rising portion 17 of the biting projection 15 is inclined.

The rising portions 17, 17 facing each other of the biting protrusion 15 are formed in a widening tapered shape in which the protruding tip side widens.

The lower layer 2 can be made of a photocurable resin or a thermosetting resin.

The lower layer 2 is made of a photocurable resin, and the photocurable resin is formed using a photocurable emulsion resin 34 as a material.

Like the screen printing mask according to the present invention, between the upper layer 1 and the lower layer 2, the upper layer 1 partially penetrates into the lower layer 2, or the lower layer 2 partially penetrates into the upper layer 1. In addition to the adhesive force derived from the photocurable resin or the like, one of the upper and lower layers 1 and 2 has a joining force derived from the encroaching portion 13 that penetrates the other. , the upper layer 1 and the lower layer 2 can be fixed in close contact with each other. As described above, according to the screen printing mask according to the present invention, the upper layer 1 and the lower layer 2 can be tightly fixed to each other as compared with the conventional mask in which the resin layer is fixed to the flat surface of the metal layer. Therefore, it is possible to more reliably prevent the upper and lower layers 1 and 2 from peeling off and damaging the mask. It should be noted that it is desirable to use a resin that cures in response to light or heat as the resin that constitutes the lower layer 2 .

The biting portion 13 is composed of a receiving recess 16 recessed between the adjacent adjustment openings 4 on the lower surface of the upper layer 1 and a biting projection 15 projecting from the upper surface of the lower layer 2 and biting into the receiving recess 16. What is and can be done. According to such a biting portion 13, the contact area between the upper and lower layers 1 and 2 can be increased by the amount of contact between the outer peripheral side surface of the biting protrusion 15 and the inner peripheral side surface of the receiving recess 16 compared to the conventional mask. Therefore, both 1 and 2 can be fixed in close contact with each other. Further, when the specific gravity of the resin forming the lower layer 2 is smaller than the specific gravity of the metal forming the upper layer 1, the ratio of the lower layer 2 made of resin increases by the amount of the encroaching portion 13, so that the weight of the mask can be reduced. .

The biting portion 13 is composed of a receiving recess 16 recessed in the upper surface of the lower layer 2 and a biting protrusion 15 projecting between the adjacent adjustment openings 4 on the lower surface of the upper layer 1 and biting into the receiving recess 16. What is and can be done. According to such a biting portion 13, the contact area between the upper and lower layers 1 and 2 can be increased by the amount of contact between the outer peripheral side surface of the biting protrusion 15 and the inner peripheral side surface of the receiving recess 16 compared to the conventional mask. Therefore, both 1 and 2 can be fixed in close contact with each other. In addition, since the portion of the upper layer 1 made of the metal layer occupies increases by the amount of the encroaching portion 13, the structural strength of the mask can be enhanced and damage to the mask due to buckling can be suppressed.

If the contact surface between the rising portion 17 of the biting projection 15 and the receiving recess 16 is provided with a gradient, the contact surface will have a gradient when the projection height of the rising portion 17 is assumed to be the same. Depending on whether or not there is a gradient, the length of the contact surface can be increased, so that the contact area between the upper and lower layers 1 and 2 can be increased.

If the rising portion 17 of the biting projection 15 is formed in a tapered shape that widens on the projecting tip side, the biting projection 15 and the receiving recess 16 can be engaged with each other in a dovetail groove. 1 and 2 can be tightly fixed.

According to the lower layer 2 made of a photocurable resin, the lower layer 2 having a complicated planar shape can be formed simply and with high accuracy by photolithography. Further, according to the lower layer 2 made of a thermosetting resin, since the thermosetting resin is superior in chemical resistance and solvent resistance as compared with the photosetting resin, printing paste containing an acid, an alkali, a solvent, or the like can be used. It can be suitably used even in the printing environment in which it is used. It is also excellent in that a cleaning agent containing an acid, an alkali, a solvent, or the like can be used to clean the mask after use.

When the lower layer 2 is made of a photo-curing resin and the photo-curing resin is formed using a photo-curing emulsion resin 34 as a material, the surface of the upper layer 1 on which the receiving recess 16 is formed is directed upward, and the upper surface of the upper layer 1 is directed upward. By pouring the photo-curing emulsion resin 34 into the surface of the emulsion resin 34, the fluidity derived from the emulsion is used to fill the receiving recess 16 with the resin 34, and the surface of the emulsion resin 34 is easily applied so as to be smooth. can do. Only by irradiating this with light and curing it, it is possible to obtain the lower layer 2 having the encroaching projections 15 and having a uniform thickness from the lower surface of the upper layer 1 . Alternatively, the surface of the upper layer 1 on which the biting protrusions 15 are formed is oriented upward, and a photocurable emulsion resin 34 is poured onto the top surface, thereby covering the biting protrusions 15 with the fluidity derived from the emulsion. The surface of the emulsion resin 34 can be easily applied so as to be smooth. Only by irradiating this with light and curing it, it is possible to obtain the lower layer 2 having the receiving recesses 16 and having a uniform thickness from the lower surface of the upper layer 1 .

1 is a longitudinal side view of a screen printing mask according to Example 1 of the present invention; FIG. 1 is an overall plan view of a screen printing mask according to Example 1, and an enlarged view of pattern openings and adjustment openings. FIG. FIG. 4 is an explanatory view showing a primary electroforming step in the method of manufacturing a screen printing mask according to Example 1; FIG. 4 is an explanatory view showing a secondary electroforming step in the method for manufacturing a screen printing mask according to Example 1; FIG. 4 is an explanatory view showing a resin layer forming step in the method for manufacturing a screen printing mask according to Example 1; FIG. 4 is a vertical cross-sectional view of a main part of a screen printing mask according to Example 2 of the present invention; FIG. 10 is a longitudinal side view of a main part of a screen printing mask according to Example 3 of the present invention; FIG. 10 is an explanatory view showing an etching step in a method for manufacturing a screen printing mask according to Example 3; FIG. 5 is a longitudinal side view of a screen printing mask according to Example 4 of the present invention. FIG. 11 is an explanatory view showing a primary electroforming step in a method for manufacturing a screen printing mask according to Example 4; FIG. 10 is an explanatory diagram showing a secondary electroforming step in the method for manufacturing a screen printing mask according to Example 4; FIG. 10 is an explanatory view showing a resin layer forming step in a method for manufacturing a screen printing mask according to Example 4; FIG. 10 is a vertical cross-sectional view of a main part of a screen printing mask according to Example 5 of the present invention; FIG. 2 is a longitudinal sectional view showing a reference example of a screen printing mask in which an upper layer made of metal and a lower layer made of resin are laminated.

Example 1 FIGS. 1 to 5 show Example 1 of a screen printing mask (hereinafter simply referred to as a printing mask) according to the present invention. In the present invention, front and back, left and right, and up and down follow the crossed arrows shown in FIGS. Dimensions such as thickness and width in each drawing of the following examples do not represent the actual state, but are shown schematically.

The printing mask is used for printing and forming the internal electrodes constituting the multilayer ceramic capacitor on the surface of the ceramic film to be printed by screen printing. In FIG. 2, the printing mask is formed in a square shape with a side of 250 mm, and when the mask is divided into four quadrants, each quadrant has a pattern forming area M for printing an electrode pattern. Furthermore, a cut mark forming area C is defined so as to surround the pattern forming area M for printing cut marks used when cutting a print object into a specified shape in a process after screen printing. The printing mask is attached to the mask fixing portion of the screen printing apparatus as a single mask or in a state in which a frame is fixed to the four peripheral edges of the mask.

As shown in FIG. 1, the printing mask has a two-layer structure in which an upper layer 1 made of metal and a lower layer 2 made of synthetic resin (resin) are laminated. , and the upper layer 1 is provided with a group of adjustment openings 4 corresponding to the pattern openings 3 . The contour shape of the adjustment opening 4 can be formed to be the same as the opening shape of the pattern opening 3 or to be slightly larger than the opening shape of the pattern opening 3 .

As shown in FIG. 2, the opening shape of the pattern openings 3 formed in the lower layer 2 is formed in a laterally long rectangular shape and arranged in a pattern forming region M in a matrix. The adjustment openings 4 formed in the upper layer 1 above the pattern openings 3 are mesh-like openings with lattice-like adjustment ribs 5 formed therein. It is formed slightly smaller than the shape of the opening. The adjustment ribs 5 are provided to adjust the amount of printing paste supplied to the pattern openings 3 .

Although not shown, in the cut mark forming area C, a cut mark opening formed in a long and narrow rectangular shape is formed in the lower layer 2, and an adjustment opening for the cut mark opening is formed in the upper layer 1 above the cut mark opening. is formed. The adjustment opening has grid-like adjustment ribs formed therein to form a mesh-like opening, and the contour shape of the adjustment opening is formed to be slightly smaller than the opening shape of the cut mark opening. The contour shape of the adjustment opening for the cut mark opening can be formed to be the same as the opening shape of the cut mark opening or to be slightly larger than the opening shape of the cut mark opening. Also, the pattern forming region M and the cut mark forming region C may have different opening shapes.

The upper surface of the upper layer 1 constitutes a squeegee surface 6, and when printing, by squeegeeing the printing paste placed on the squeegee surface 6 with a squeegee S, the pattern openings 3 and the cut mark openings are filled with the printing paste, A printing layer composed of an electrode pattern matching the pattern openings 3 and a cut pattern matching the cut mark openings is formed on the surface to be printed. The squeegee S forms a print layer while moving from the front side to the rear side of the print mask while its tip is in contact with the squeegee surface 6 . The term "printing paste" as used herein is a concept including solder paste, cream solder, liquid solder, conductive ink, and the like.

Between the upper layer 1 and the lower layer 2, a biting portion 13 is provided for firmly fixing the two layers 1 and 2 together. The upper layer 1 made of metal is formed by laminating an upper first metal layer 11 having a relatively large thickness and a lower second metal layer 12 having a relatively small thickness. 12 is formed with a grid-shaped notch 14 vertically penetrating between the adjacent adjustment openings 4 . In the lower surface of the upper layer 1, the upper surface of the notch 14 is covered with the first metal layer 11, thereby forming a receiving recess 16A (16) for receiving the biting protrusion 15A (15). Receiving recesses 16A are formed in a grid pattern corresponding to notches 14. As shown in FIG. The thickness of the upper layer 1 is set to 18 μm, and the depth of the receiving recess 16A is set to 3 μm.

A lower layer 2 made of synthetic resin is tightly fixed to the lower surface of the upper layer 1 to form pattern openings 3 . A biting protrusion 15A constituting a biting portion 13 is formed on the upper surface of the lower layer 2 so as to protrude upward. In this embodiment, the biting protrusion 15A provided in the lower layer 2 and the receiving recess 16A provided in the upper layer 1 form a biting portion 13 in which the lower layer 2 partially intrudes into the upper layer 1 . The thickness of the lower layer 2 excluding the encroachment 15A is set to 3 μm. Therefore, the total thickness of the print mask is 21 μm.

In this way, the receiving recess 16A (16) recessed between the adjacent adjustment openings 4 on the lower surface of the upper layer 1 and the biting protrusion 15A (15) protruding from the upper surface of the lower layer 2 and cutting into the receiving recess 16A. ) is provided, the upper and lower layers 1 and 2 are separated by the amount of contact between the outer peripheral side surface of the biting protrusion 15A and the inner peripheral side surface of the receiving recess 16A compared to the conventional mask. Since the contact area of 1 and 2 can be increased, both 1 and 2 can be tightly fixed. In addition, since the ratio of the lower layer 2 made of synthetic resin increases by the amount of the biting portion 13, there is an advantage that the weight of the printing mask can be reduced. The contact area between the upper layer 1 and the lower layer 2 can be increased by increasing the depth of the receiving recess 16A. However, as the depth increases, the structural strength of the upper layer 1 decreases, and there is a risk that the printing mask will be damaged such as buckling due to the pressing force of the squeegee S during printing. is preferably set to less than half the thickness of the

An example of the manufacturing method of the printing mask according to this embodiment is shown in FIGS. 3 to 5. FIG. 3(a) to (d), the secondary electroforming process shown in FIGS. 4(a) to (d), and the resin shown in FIGS. 5(a) to (c). It is formed through a layer forming process. In the primary electroforming step, as shown in FIG. 3A, a negative first photoresist layer 21 is formed on the surface of a plate-like stainless steel electroformed matrix 20 having conductivity. Next, a first pattern film 22 (photomask) is adhered onto the first photoresist layer 21 .

Next, the inside of the furnace of the ultraviolet irradiation device having the ultraviolet lamp 23 is preheated to the furnace temperature during the exposure work. After preheating is completed, the laminate shown in FIG. The first photoresist layer 21 is exposed through the first pattern film 22 . The laminated body after the exposure is taken out, the first pattern film 22 is removed from the first photoresist layer 21, and the unexposed portion of the first photoresist layer 21 is dissolved and removed (developed), thereby obtaining the structure shown in FIG. 3(b). A primary pattern resist 24 is formed on the electroformed matrix 20 as shown. The primary pattern resist 24 is composed of a resist body corresponding to the openings of the adjustment openings 4 for the pattern openings 3 and the adjustment openings for the cut mark openings.

Next, as shown in FIG. 3C, the surface of the electroforming matrix 20 that is not covered with the primary pattern resist 24 is electroformed (plated) so that the surface within the height range of the primary pattern resist 24 is subjected to an electroforming (plating) process. to form the primary electroformed layer 25 that will become the first metal layer 11 . After forming the primary electroformed layer 25, the surfaces of the primary pattern resist 24 and the primary electroformed layer 25 are polished and smoothed to obtain the state shown in FIG. 3(d).

In the secondary electroforming step, as shown in FIG. 4A, a negative type second photoresist layer 28 is formed on the surfaces of the primary pattern resist 24 and the primary electroforming layer 25 . Next, a second pattern film 29 (photomask) is adhered onto the second photoresist layer 28 . The second pattern film 29 has transparent holes corresponding to the openings of the adjustment openings 4 and the cutouts 14 . Next, the second photoresist layer 28 is exposed through the second pattern film 29 by irradiating ultraviolet light from the ultraviolet lamp 23 . After the exposure, the second pattern film 29 is removed from the second photoresist layer 28, and the unexposed portions of the second photoresist layer 28 are dissolved and removed (developed) to form the primary pattern as shown in FIG. 4(b). A secondary pattern resist 30 is formed on the resist 24 and the primary electroformed layer 25 . The secondary pattern resist 30 is composed of a resist body corresponding to the openings of the adjustment opening 4 for the pattern opening 3 and the adjustment opening for the cut mark opening, and a resist body corresponding to the notch 14 .

Next, as shown in FIG. 4C, the surface of the primary electroformed layer 25 that is not covered with the secondary pattern resist 30 is subjected to an electroforming (plating) process to increase the height of the secondary pattern resist 30. A secondary electroformed layer 31 that becomes the second metal layer 12 is formed within the range. After the formation of the secondary electroformed layer 31, the surfaces of the secondary pattern resist 30 and the secondary electroformed layer 31 are polished and smoothed, then the secondary pattern resist 30 is removed, and further the electroformed matrix 20 is removed. Then, the mask front stage body shown in FIG. 4(d) can be obtained. After removing the electroformed matrix 20 and the secondary pattern resist 30, the surfaces of the secondary pattern resist 30 and the secondary electroformed layer 31 may be polished and smoothed. Moreover, depending on the form of the printing mask, the secondary pattern resist 30 may be formed so as to cover the entire regions to be both adjustment openings. In this case, the secondary electroformed layer 31 is not formed in the portions corresponding to the meshes of both adjustment openings. Further, polishing in each step can be applied as necessary.

In the resin layer forming step, the mask front body is temporarily fixed on a surface plate, and a photocurable emulsion resin (photocurable resin) 34 is poured onto the surface of the mask front body, as shown in FIG. Emulsion resin 34 is uniformly applied to the surfaces of the primary and secondary electroforming layers 25 and 31 and the primary pattern resist 24 by utilizing the fluidity derived from the emulsion. Next, a third pattern film 35 (photomask) made of a glass mask is brought into close contact with the emulsion resin 34 . Next, the ultraviolet lamp 23 is used to irradiate ultraviolet light to expose the emulsion resin 34 through the third pattern film 35 to harden it. After curing, the third pattern film 35 is removed from the emulsion resin 34 and the uncured portion of the emulsion resin 34 is removed, thereby forming a pattern on the primary and secondary electroformed layers 25 and 31 as shown in FIG. 5(b). Then, a lower layer 2 having openings corresponding to the pattern openings 3 is formed in the mask front body. Finally, by removing the primary pattern resist 24, the finished print mask shown in FIG. 5(c) can be obtained. The photocurable emulsion resin 34 may be one that cures by reacting to visible light instead of one that cures by reacting to ultraviolet rays. It may also be a thermosetting emulsion resin (resin) that cures in response to heat.

Since the lower layer 2 of this embodiment is composed of a photocurable resin, the lower layer 2 having a complicated planar shape can be formed simply and with high precision by photolithography. Since the photo-curing resin forming the lower layer 2 is formed from the photo-curing emulsion resin 34, the surface of the upper layer 1 on which the receiving recess 16A is formed faces upward, and the photo-curing resin is placed on the upper surface. By pouring the emulsion resin 34, the emulsion resin 34 can be easily applied so as to smooth the surface while filling the receiving recess 16A with the same resin 34 by utilizing the fluidity derived from the emulsion. . Only by irradiating this with light and curing it, it is possible to obtain the lower layer 2 having the encroaching protrusions 15A and having a uniform thickness from the lower surface of the upper layer 1 .

The lower layer 2 can also be composed of a thermosetting resin. Thermosetting resins are superior in chemical resistance and solvent resistance to photo-setting resins, so they can be suitably used even in printing environments where printing pastes containing acids, alkalis, solvents, or the like are used. It is also excellent in that a cleaning agent containing an acid, an alkali, a solvent, or the like can be used for cleaning the mask after use.

In the manufacturing method described above, the resin layer forming step is performed without removing the primary pattern resist 24, but the resin layer forming step may be performed after removing the primary pattern resist 24 together with the secondary pattern resist 30. It is possible. In this case, it is possible to prevent the lower layer 2 from falling off and being removed together with the primary pattern resist 24 when the primary pattern resist 24 is removed. Further, the electroformed matrix 20 may be removed after the lower layer 2 is formed.

Moreover, the following method may be sufficient as a resin layer formation process. A plate-shaped thermoplastic resin plate heated to a softening temperature or higher is temporarily fixed on a surface plate or placed on the surface of a mask preform formed by electroforming on an electroforming master 20, and the softened thermoplastic resin plate is placed. It is pressed flat against the front stage of the mask. As a result, part of the resin plate enters the receiving recess 16A. After the thermoplastic resin plate is cooled and hardened again, the lower layer 2 is formed by sublimating and removing unnecessary portions of the thermoplastic resin plate by laser processing or by melting and removing by etching to form pattern openings 3. Form.

(Example 2) Fig. 6 shows Example 2 of a screen printing mask (hereinafter simply referred to as a printing mask) according to the present invention. The present embodiment differs from the first embodiment in that the rising portions 17, 17 facing each other of the biting protrusion 15A (15) are inclined. The rising portions 17, 17 are formed in a tapered shape that widens on the projecting tip side. The slope of the rising portion 17 can be formed by obliquely irradiating ultraviolet light from the translucent holes corresponding to the notch portions 14 of the second pattern film 29 when exposing the second pattern resist layer 28 . Since other parts are the same as those of the first embodiment, the same reference numerals are given to the same members, and the description thereof will be omitted. The same applies to the following examples.

As described above, the contact surface between the biting projection 15A and the receiving recess 16A at the rising portion 17 of the biting projection 15A is inclined. Since the length of the contact surface can be increased when there is a slope, the contact area between the upper and lower layers 1 and 2 can be further increased. In addition, since the rising portion 17 of the biting projection 15A is formed in a tapered shape, the biting projection 15A and the receiving recess 16A can be engaged with each other in a dovetail shape, so that the upper and lower layers 1 and 2 can be engaged with each other. Further, it can be firmly adhered and fixed.

Example 3 FIGS. 7 and 8 show Example 3 of a screen printing mask (hereinafter simply referred to as a printing mask) according to the present invention. The present embodiment differs from the first embodiment in that the upper layer 1 is formed of only the first metal layer 11 . In addition, although the manufacturing method is the same in the primary electroforming process and the resin layer forming process, it differs from the first embodiment in that the etching process is performed instead of the secondary electroforming process.

In the etching step, as shown in FIG. 8A, a negative type second photoresist layer 28 is formed on the surfaces of the primary pattern resist 24 and the primary electroformed layer 25 . Next, an etching pattern film 38 (photomask) is adhered onto the second photoresist layer 28 . The etching pattern film 38 is formed with transparent holes corresponding to the receiving recesses 16A. Next, the second photoresist layer 28 is exposed through the etching pattern film 38 by irradiating ultraviolet light from the ultraviolet lamp 23 . After the exposure, the etching pattern film 38 is removed from the second photoresist layer 28, and the unexposed portions of the second photoresist layer 28 are dissolved and removed (developed) to form the primary pattern resist as shown in FIG. 8(b). 24 and the primary electroformed layer 25, an etching pattern resist 39 is formed. The etching pattern resist 39 is composed of a resist body corresponding to the receiving recess 16A.

Next, as shown in FIG. 8(c), the surface of the primary electroformed layer 25 not covered with the etching pattern resist 39 is etched to form the receiving recess 16A in the primary electroformed layer 25. Next, as shown in FIG. After the etching process, the etching pattern resist 39 is removed, and the electroformed matrix 20 is removed to obtain the mask preform shown in FIG. 8(d).

Since the upper layer 1 of the present embodiment is composed only of the first metal layer 11, its structural strength can be improved more than the upper layer 1 of the first embodiment composed of the first and second metal layers 11 and 12. , the print mask of Examples 1 and 2 can be more resistant to deflection deformation.

(Example 4) Figs. 9 to 12 show Example 4 of a screen printing mask (hereinafter simply referred to as a printing mask) according to the present invention. In this embodiment, the structure of the biting portion 13 is different from that in the first embodiment. Specifically, as shown in FIG. 9, the upper layer 1 is formed with a biting protrusion 15B (15), and the lower layer 2 is formed with a receiving recess 16B (16). The upper layer 1 made of metal is configured by laminating an upper first metal layer 11 having a relatively large thickness and a lower second metal layer 12 having a relatively small thickness. The second metal layer 12 is formed in a grid pattern between the adjacent adjustment openings 4 on the lower surface of the first metal layer 11 in the pattern forming region M, and the second metal layer 12 forms the encroaching protrusion 15B. is configured as A receiving recess 16B (16) for receiving the biting protrusion 15B is formed on the upper surface of the lower layer 2 made of synthetic resin. The riser 17 is covered with the lower layer 2 . In this embodiment, an encroaching portion 13 in which the upper layer 1 partially intrudes into the lower layer 2 is provided by the encroaching protrusion 15B provided in the upper layer 1 and the receiving recess 16B provided in the lower layer 2 . The thickness of the first metal layer 11 is set to 18 μm, and the thickness of the lower layer 2 is set to 3 μm. Therefore, the total thickness of the print mask is 21 μm. The thickness of the second metal layer 12, ie, the encroaching protrusion 15B is set to 1.5 μm.

As described above, the receiving recess 16B (16) formed on the upper surface of the lower layer 2 and the biting protrusion 15B (16) formed on the lower surface of the upper layer 1 between the adjacent adjustment openings 4 and cutting into the receiving recess 16B ( 15) According to the biting portion 13 configured by 1), the contact between the upper and lower layers 1 and 2 is reduced by the amount of contact between the outer peripheral side surface of the biting protrusion 15B and the inner peripheral side surface of the receiving recess 16B compared to the conventional mask. Since the area can be increased, both 1 and 2 can be tightly fixed. In addition, since the proportion of the metal layer 1 occupied by the upper layer 1 increases by the amount of the encroaching portion 13, there is an advantage that the structural strength can be enhanced and damage to the printing mask due to buckling can be suppressed.

10 to 12 show an example of a method for manufacturing a printing mask according to this embodiment. 10(a) to (d), the secondary electroforming process shown in FIGS. 11(a) to (d), and the resin shown in FIGS. 12(a) to (c). It is formed through a layer forming process. In the primary electroforming step, as shown in FIG. 10A, a negative first photoresist layer 21 is formed on the surface of a plate-like electroformed master mold 20 made of stainless steel having conductivity. Next, a first pattern film 22 is adhered onto the first photoresist layer 21 . Note that the thickness of the first metal layer 11 is thicker than that of the first embodiment, so the thickness of the first photoresist layer 21 is increased.

Next, the inside of the furnace of the ultraviolet irradiation device having the ultraviolet lamp 23 is preheated to the furnace temperature during the exposure work. When the preheating is completed, the laminate shown in FIG. 10(a) is placed in the furnace of the ultraviolet irradiation device, and after the laminate is adapted to the temperature inside the furnace, ultraviolet light is irradiated from the ultraviolet lamp 23. The first photoresist layer 21 is exposed through the first pattern film 22 . The laminated body after the exposure is taken out, the first pattern film 22 is removed from the first photoresist layer 21, and the unexposed portion of the first photoresist layer 21 is dissolved and removed (developed), thereby obtaining the structure shown in FIG. 10(b). A primary pattern resist 24 is formed on the electroformed matrix 20 as shown. The primary pattern resist 24 is composed of a resist body corresponding to the openings of the adjustment openings 4 for the pattern openings 3 and the adjustment openings for the cut mark openings.

Next, as shown in FIG. 10C, the surface of the electroforming matrix 20 that is not covered with the primary pattern resist 24 is electroformed (plated) so that the surface of the electroforming master 20 is formed within the height range of the primary pattern resist 24 . to form the primary electroformed layer 25 that will become the first metal layer 11 . After forming the primary electroformed layer 25, the surfaces of the primary pattern resist 24 and the primary electroformed layer 25 are polished and smoothed, resulting in the state shown in FIG. 10(d).

In the secondary electroforming process, as shown in FIG. 11A, a negative type second photoresist layer 28 is formed on the surfaces of the primary pattern resist 24 and the primary electroforming layer 25 . Next, a second pattern film 29 is adhered onto the second photoresist layer 28 . The second pattern film 29 has light-transmitting holes corresponding to the second metal layer 12 (biting projections 15B). Next, the second photoresist layer 28 is exposed through the second pattern film 29 by irradiating ultraviolet light from the ultraviolet lamp 23 . After exposure, the second pattern film 29 is removed from the second photoresist layer 28, and the unexposed portions of the second photoresist layer 28 are dissolved and removed (developed) to form the primary pattern as shown in FIG. 11(b). A secondary pattern resist 30 is formed on the resist 24 and the primary electroformed layer 25 . The secondary pattern resist 30 is composed of a resist body corresponding to the second metal layer 12 .

Next, as shown in FIG. 11(c), the surface of the primary electroformed layer 25 not covered with the secondary pattern resist 30 is subjected to an electroforming (plating) process to increase the height of the secondary pattern resist 30. A secondary electroformed layer 31 that becomes the second metal layer 12 is formed within the range. After the formation of the secondary electroformed layer 31, the surfaces of the secondary pattern resist 30 and the secondary electroformed layer 31 are polished and smoothed, then the secondary pattern resist 30 is removed, and further the electroformed matrix 20 is removed. Then, the mask front stage body shown in FIG. 11(d) can be obtained. After removing the electroformed matrix 20 and the secondary pattern resist 30, the surfaces of the secondary pattern resist 30 and the secondary electroformed layer 31 may be polished and smoothed. In addition, using an electroforming matrix in which a depression corresponding to the second metal layer 12 (biting protrusion 15B) is formed, the primary electroforming layer 25 that becomes the second metal layer 12 is formed in the depression in the primary electroforming step. It can also be obtained by forming a secondary electroformed layer 31 that becomes the first metal layer 11 in a secondary electroforming process after formation.

In the resin layer forming step, the mask front body is temporarily fixed on a surface plate, and as shown in FIG. Emulsion resin 34 is uniformly applied to the surfaces of the primary and secondary electroforming layers 25 and 31 and the primary pattern resist 24 by utilizing the fluidity derived from the emulsion. Next, a third pattern film 35 is adhered onto the emulsion resin 34 . Next, the ultraviolet lamp 23 is used to irradiate ultraviolet light to expose the emulsion resin 34 through the third pattern film 35 to harden it. After curing, the third pattern film 35 is removed from the emulsion resin 34 and the uncured portion of the emulsion resin 34 is removed, thereby forming a pattern on the primary and secondary electroformed layers 25 and 31 as shown in FIG. 12(b). Then, a lower layer 2 having openings corresponding to the pattern openings 3 is formed in the mask front body. Finally, by removing the primary pattern resist 24, the finished print mask shown in FIG. 12(c) can be obtained.

Since the lower layer 2 of this embodiment is composed of a photocurable resin, the lower layer 2 having a complicated planar shape can be formed simply and with high precision by photolithography. In addition, since the photo-curing resin constituting the lower layer 2 is formed by using the photo-curing emulsion resin 34 as a raw material, the surface of the upper layer 1 on which the biting protrusion 15B is formed is oriented upward, and the photo-curing resin By pouring the emulsion resin 34, the surface of the emulsion resin 34 can be easily coated so as to be smooth while covering the biting protrusion 15B with the fluidity derived from the emulsion. Only by irradiating this with light and curing it, it is possible to obtain the lower layer 2 having the receiving recess 16B and having a uniform thickness from the lower surface of the upper layer 1 . Also in this embodiment, the electroformed matrix 20 may be removed after the lower layer 2 is formed.

(Example 5) Fig. 13 shows Example 5 of a screen printing mask (hereinafter simply referred to as a printing mask) according to the present invention. In this embodiment, the shape of the biting protrusions 15B (15) is different from that of the fourth embodiment, and three (plural) biting protrusions 15B are formed in the upper layer 1, and the receiving recesses 16B corresponding to the biting protrusions 15B are formed. was formed in the lower layer 2. The receiving recesses 16B at both ends are open on one side on the pattern opening 3 side. By providing a plurality of encroaching portions 13 in this manner, the contact area between the upper layer 1 and the lower layer 2 can be increased, so that the two layers 1 and 2 can be tightly fixed.

As described above, in the printing mask of each of the above-described embodiments, between the upper layer 1 and the lower layer 2, the upper layer 1 partially intrudes into the lower layer 2, or the lower layer 2 overlaps with the upper layer 1. Since the biting portion 13 that partially penetrates is provided, in addition to the adhesive force derived from the photocurable synthetic resin, the upper layer 1 is secured by the bonding force derived from one of the upper and lower layers 1 and 2 biting into the other. and the lower layer 2 can be tightly fixed. Therefore, compared with the conventional mask in which the resin layer is fixed to the flat surface of the metal layer, the upper layer 1 and the lower layer 2 can be adhered and fixed more firmly, so that the mask will not be damaged due to peeling of the upper and lower layers 1 and 2. can be prevented.

The biting projection 15 and the receiving recess 16 that constitute the biting portion 13 in each of the above-described embodiments are formed of stepless projections and recesses, but may be formed of multi-step projections and recesses. The dimensions and the like of each part are not limited to those shown in the above embodiments. The printing mask of the present invention is not limited to one used for printing internal electrodes constituting a multilayer ceramic capacitor. Also, the mask structure of the printing mask can be diverted to a vapor deposition mask, a solder ball mounting mask, and a solder ball adsorption mask.

FIG. 14 shows a reference example of a screen printing mask in which an upper layer 1 made of metal and a lower layer 2 made of resin are laminated. In this reference example, the encroaching portion 13 referred to in the present invention is not provided, and the lower layer 2 is formed only on the lower surface of the second metal layer 12 in the fourth embodiment. In the resin layer forming step in Example 4, after applying the photocurable emulsion resin 34 , a pattern film corresponding to the second metal layer 12 is adhered onto the emulsion resin 34 . After the emulsion resin 34 is cured by irradiating it with ultraviolet light from the ultraviolet lamp 23, the pattern film and the uncured portion of the emulsion resin 34 are removed. Thus, a print mask according to the reference example is obtained.

1 Upper layer 2 Lower layer 3 Pattern opening 4 Adjustment opening 13 Biting portion 15 Biting protrusion 16 Receiving concave portion 17 Rising portion 34 Emulsion resin

Claims (5)

a lower layer (2) made of resin having a group of pattern openings (3);
a top layer (1) made of metal having a group of alignment openings (4) corresponding to the pattern openings (3);
with
The lower surface of the lower layer (2) constitutes a surface facing the object to be printed, and an encroaching portion (13) is provided between the upper layer (1) and the lower layer (2),
A biting portion (13) is formed by projecting between a receiving recess (16) formed in the upper surface of the lower layer (2) and adjacent adjustment openings (4) in the lower surface of the upper layer (1). ) and a biting protrusion (15) that bites into the screen printing mask. 2. The screen printing mask according to claim 1 , wherein the contact surface between the biting projection (15) and the receiving recess (16) at the rising portion (17) of the biting projection (15) is sloped. 3. The screen printing mask according to claim 2 , wherein the rising portions (17, 17) facing each other of the biting projection (15) are formed in a widening tapered shape in which the projecting tip side widens. 4. A screen printing mask according to any one of claims 1 to 3 , wherein the lower layer (2) comprises a photocurable resin or a thermosetting resin. 5. The screen printing mask according to claim 4 , wherein the lower layer (2) is made of a photocurable resin and is formed using a photocurable emulsion resin (34) as a material.

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