Screen printing method and screen printing device

Abstract

To provide a screen printing method and a screen printing apparatus in which a printing pattern can be formed by screen printing on the surface of a protrusion of a substrate having the protrusion protruded from a principal surface.SOLUTION: In forming a printing pattern by screen printing on a surface of a protrusion TB protruded from a principal surface SM of a substrate KB, a mesh screen 22 on which a printing opening for forming a printing pattern is formed is pressed against the protrusion TB by a squeegee 33 to copy the shape of an apex of the protrusion TB, paste Pst is pushed toward the substrate KB side from the printing opening by moving the squeegee 33 while maintaining the state, and the printing pattern is formed at the apex of the protrusion TB.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a screen printing method and a screen printing apparatus for forming a print pattern by screen printing on the surface of a convex portion protruding from a main surface of a substrate. [Background technology]

[0002] Conventionally, there has been known a method of screen-printing a print pattern onto a main surface of a substrate. Also, there has been known a method of screen-printing a print pattern onto a main surface of a substrate having protrusions protruding from the main surface, while avoiding the protrusions (see, for example, Patent Documents 1 and 2 listed below). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-139019 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-211862 Summary of the Invention [Problem to be solved by the invention]

[0004] However, for a substrate having protrusions protruding from its main surface, a technique for forming a pattern on the surface of the protrusions by screen printing has not yet been established.

[0005] Therefore, an object of the present invention is to provide a screen printing method and a screen printing apparatus that can form a printing pattern on the surface of a convex portion of a substrate that has a convex portion protruding from its main surface by screen printing. [Means for solving the problem]

[0006] The screen printing method of the present invention is a screen printing method for forming a printing pattern by screen printing on the surface of a convex portion protruding from a main surface, which is a flat upper surface, of a substrate, in which a screen having printing openings for forming the printing pattern formed therein is pressed against the convex portion with a squeegee to conform to the shape of the top of the convex portion, and while maintaining this state, the squeegee is moved to extrude paste from the printing openings toward the substrate, thereby forming a printing pattern on the top of the convex portion, and while the squeegee is pressing the screen downward, When it is located on the convex part The lower end of the squeegee is located at a position lower than the height of the convex portion of the substrate and higher than the height of the main surface of the substrate.

[0007] The screen printing apparatus of the present invention is a screen printing apparatus for forming a printing pattern by screen printing on the surface of a convex portion protruding from a main surface, which is a flat upper surface, of a substrate, and is equipped with a screen in which printing openings for forming the printing pattern are formed, a squeegee made of a plate-shaped member having corners at the lower end, and a squeegee moving means for pressing the screen against the convex portion with the corners of the squeegee to conform to the shape of the top of the convex portion, and by moving the squeegee while maintaining this state, pushing paste out from the printing openings toward the substrate and forming the printing pattern on the top of the convex portion, and When it is located on the convex part The lower end of the squeegee is located at a position lower than the height of the convex portion of the substrate and higher than the height of the main surface of the substrate. [Effects of the Invention]

[0008] According to the present invention, a print pattern can be formed by screen printing on the surface of the protrusions of a substrate having protrusions protruding from its main surface. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing a schematic configuration of a screen printing apparatus according to an embodiment of the present invention. [Figure 2]FIG. 1 is a side view showing a schematic configuration of a screen printing apparatus according to an embodiment of the present invention. [Figure 3] 1 is a perspective view of a substrate on which paste is printed by a screen printing apparatus according to an embodiment of the present invention; [Figure 4] 1 is a cross-sectional view of a portion of a screen printing apparatus according to an embodiment of the present invention; [Figure 5] FIG. 1 is a side view showing a schematic configuration of a screen printing apparatus according to an embodiment of the present invention. [Figure 6] 1 is a cross-sectional view of a portion of a screen printing apparatus according to an embodiment of the present invention; [Figure 7] FIG. 1A is a partial cross-sectional view of a screen printing apparatus according to an embodiment of the present invention; FIG. 1B is a plan view of a mesh screen; [Figure 8] FIG. 1 is a side view showing a schematic configuration of a screen printing apparatus according to an embodiment of the present invention. [Figure 9] 1 is a cross-sectional view of a portion of a screen printing apparatus according to an embodiment of the present invention; [Figure 10] FIG. 1A is a partial cross-sectional view of a screen printing apparatus according to an embodiment of the present invention; FIG. 1B is a plan view of a mesh screen; [Figure 11] 1 is a perspective view of a substrate on which a print pattern is formed by a screen printing apparatus according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Figures 1 and 2 show a screen printing apparatus 1 according to one embodiment of the present invention. The screen printing apparatus 1 is an apparatus for applying a printing pattern to the surface of a substrate KB by performing screen printing on the substrate KB.

[0011] In this embodiment, the substrate KB to be printed by the screen printing apparatus 1 is made of a flat plate-like member that extends along the XY plane as a whole, as shown in Fig. 3. The substrate KB has a flat upper surface (referred to as the "main surface SM") and has multiple protrusions TB protruding upward from multiple locations on the main surface SM. Each of the multiple protrusions TB has a curved surface, and an area of ​​the curved surface near the top forms a pattern formation region PR (the area surrounded by a dashed line in Fig. 3) where a pattern is formed by the screen printing apparatus 1.

[0012] 1 and 2, the screen printing apparatus 1 includes a substrate stage 11, a screen mask 12, a print head 13, and a print head drive unit 14. For ease of explanation in this embodiment, one direction in a horizontal plane is defined as the left-right direction (X direction), and the up-down direction is defined as the Z direction. Furthermore, the direction in the horizontal plane that is perpendicular to the Y direction is defined as the front-back direction (Y direction).

[0013] 1 and 2, the substrate stage 11 has a substrate holding surface 11M with a flat upper surface. The substrate holding surface 11M is provided with a plurality of suction openings (not shown). The substrate stage 11 holds the substrate KB on the substrate holding surface 11M by suctioning the substrate KB through these plurality of suction openings. The substrate stage 11 can be moved in a horizontal plane by a substrate stage moving mechanism 11K.

[0014] 1 and 2, the screen mask 12 includes a screen holding frame 21 and a mesh screen 22. The screen holding frame 21 is made of a rectangular frame member extending along the XY plane. The mesh screen 22 has four sides held by the screen holding frame 21 and is flexible enough to bend in the out-of-plane direction (Z direction). A plurality of printing openings 22K are provided in the center of the mesh screen 22 for forming a printing pattern on the surface of the protruding portions TB of the substrate KB.

[0015] 1 and 2, the print head 13 includes a head base 31, a squeegee holding unit 32, a squeegee 33, a holding member 34, and a backup member 35. The print head drive unit 14 drives the print head 13 in the Z direction and the Y direction. The print head 13 is driven by the print head drive unit 14 in one direction (forward in this embodiment) of the Y direction (front-back direction) to scrape together the paste Pst supplied onto the mesh screen 22 (referred to as "squeegeeing").

[0016] 1 and 2, the head base 31 of the print head 13 is the part that is directly driven by the print head drive unit 14 and has a shape that extends in the X direction as a whole. The squeegee holder 32 is a member that extends downward from the bottom end of the head base 31 and holds the upper end of the squeegee 33. The squeegee 33 is a generally rectangular plate-like member made of an elastic material such as urethane. The squeegee 33 is a member that scrapes the paste Pst on the mesh screen 22 during squeegeeing, and its lower end extends obliquely in the direction (rearward) opposite the direction of travel (forward) during squeegeeing. The lower end of the squeegee 33 forms a downwardly protruding corner 33E (FIG. 2).

[0017] 1 and 2, holding member 34 is made of a plate-like member extending in the X direction and is provided from the lower end of squeegee holding portion 32 along the paste scraping surface (here, the front surface) of squeegee 33. Backup member 35 is also made of a plate-like member extending in the X direction and is provided from the lower end of squeegee holding portion 32 along the surface of squeegee 33 opposite the paste scraping surface (here, the rear surface). In other words, squeegee 33 is attached to the lower part of squeegee holding portion 32 in a state where it is sandwiched between holding member 34 and backup member 35 (FIG. 2). The lower end side of backup member 35 extends to the vicinity of the lower end (corner 33E) of squeegee 33.

[0018] When a printing pattern is formed by printing the paste Pst on the surface of each of the plurality of protrusions TB of the substrate KB (more specifically, on the surface within the pattern formation region PR) using the screen printing apparatus 1 configured as described above, the substrate KB is first held on the substrate holding surface 11M of the substrate stage 11. Then, the substrate stage 11 (i.e., the substrate KB) is positioned below the screen mask 12 by the substrate stage movement mechanism 11K (FIG. 2). At this time, the substrate KB is positioned so that the upper surfaces of the protrusions TB do not come into contact with the mesh screen 22, as shown in FIG. 4 (the V1-V1 cross-sectional view in FIG. 2). The substrate stage movement mechanism 11K also aligns the horizontal position (direction along the XY plane) of the pattern formation region PR of the substrate KB with the position of the printing openings 22K of the mesh screen 22.

[0019] Once the substrate stage 11 is positioned below the screen mask 12, the print head driver 14 positions the print head 13 behind the screen mask 12. At this time, the print head 13 is positioned so that the paste scraping surface (front surface) of the squeegee 33 is positioned behind the paste Pst supplied onto the mesh screen 22 and so that the corners 33E do not come into contact with the mesh screen 22 (FIG. 2).

[0020] After positioning the print head 13 behind the screen mask 12, the print head driver 14 lowers the print head 13 (arrow A in FIG. 5) to place the print head 13 in its initial position. When the print head 13 is in its initial position, the corners 33E of the squeegee 33 abut against the mesh screen 22 and press down on that portion (FIGS. 5, 6, and 7(a)). Here, FIG. 6 is a cross-sectional view taken along line V2-V2 in FIG. 5, and FIG. 7(a) is a cross-sectional view taken along line V3-V3 in FIG. 6.

[0021] When the print head 13 is in the initial position, the portion where the corner 33E of the squeegee 33 abuts against the mesh screen 22 is a band-shaped region (hereinafter referred to as the "squeegee abutment portion 22Q") as shown in FIG. 7(b). Here, FIG. 7(b) is a plan view of the mesh screen 22 at the location shown in FIG. 7(a). When the print head 13 is in the initial position, the lower end (corner 33E) of the squeegee 33 is located at a position lower than the height H1 of the protrusion TB of the substrate KB and higher than the height H2 of the main surface SM, as shown in FIG. 7(a).

[0022] After positioning the print head 13 at its initial position, the print head driver 14 moves the print head 13 forward (arrow B in FIG. 8). This causes the corners 33E of the squeegee 33 to move forward while remaining in contact with the mesh screen 22, scraping the paste Pst on the mesh screen 22 forward. When the corners 33E of the squeegee 33 reach the protrusions TB of the substrate KB as the squeegee 33 moves forward, the corners 33E of the squeegee 33 elastically deform to conform to the surface shape of the protrusions TB, and press a portion of the mesh screen 22 against the surface of the protrusions TB (FIGS. 9 and 10(a)). Here, FIG. 9 is a cross-sectional view taken along line V4-V4 in FIG. 8, and FIG. 10(a) is a cross-sectional view taken along line V5-V5 in FIG. 9.

[0023] When the corners 33E of the squeegee 33 conform to the surface shape of the protrusions TB, as shown in FIG. 10(b), the portions of the squeegee abutment portion 22Q where the mesh screen 22 is in contact with the protrusions TB (contact portions S1) are wider in the front-to-rear direction than the portions of the mesh screen 22 on either side that are not in contact with the protrusions TB (non-contact portions S2). This is because the amount of deformation of the portions of the corners 33E of the squeegee 33 that conform to the surface shape of the protrusions TB is greater than the amount of deformation of the portions that do not conform to the surface shape of the protrusions TB (portions on both sides of the protrusions TB). Note that FIG. 10(b) is a plan view of the mesh screen 22 at the location shown in FIG. 10(a), and the region SR shown in FIG. 10(b) is the region where the mesh screen 22 is in contact with the protrusions TB. The mesh screen 22 in the region SR is in contact with the surface shape of the protrusions TB. This region SR moves forward as the squeegee 33 moves forward.

[0024] As the print head 13 moves further forward, the corners 33E of the squeegee 33 pass over the printing openings 22K of the mesh screen 22 that are in close contact with the protrusions TB of the substrate KB. At this time, the corners 33E of the squeegee 33 push the paste Pst toward the substrate KB, so that the paste Pst is applied to the surfaces of the protrusions TB through the printing openings 22K.

[0025] The portion of the mesh screen 22 that the corner 33E of the squeegee 33 has passed over attempts to return to its original state (the state before being pushed downward by the squeegee 33) due to the restoring force of the mesh screen 22 itself. As a result, after the corner 33E of the squeegee 33 has passed, the mesh screen 22 separates from the surface of the protruding portion TB, resulting in what is known as plate separation. As a result, a printing pattern PPT having a shape corresponding to the shape of the printing opening 22K is formed on the surface of the protruding portion TB (more specifically, on the surface of the pattern formation region PR) (FIG. 11).

[0026] Here, while the squeegee 33 is conforming the corners 33E to the surface shape of the protrusions TB, it receives a large reaction force R in the direction of pushing up (warping) from the protrusions TB through the corners 33E (FIG. 10(a)). However, because a backup member 35 is provided on the rear surface of the squeegee 33, the entire squeegee 33 does not warp or deform, except for localized areas such as the corners 33E. This allows the squeegee 33 to closely adhere the mesh screen 22 to the surface of the protrusions TB over a wide area. Furthermore, because the paste Pst is pressed into the printing openings 22K with an appropriate printing pressure, the printing pattern PPT can be reliably formed over a wide area of ​​the curved surface of the protrusions TB.

[0027] As described above, the screen printing apparatus 1 in this embodiment comprises a mesh screen 22 as a screen in which printing openings 22K for forming the printing pattern PPT are formed, a squeegee 33 consisting of a plate-shaped member having corners 33E at the bottom end, and a print head drive unit 14 as a squeegee moving means that presses the mesh screen 22 against the surface of the convex portion TB with the corners 33E of the squeegee 33 to conform to the shape of the top of the convex portion TB, and moves while maintaining this state, thereby pushing the paste Pst from the printing openings 22K toward the substrate KB and forming the printing pattern PPT on the top of the convex portion TB, and is configured to form a printing pattern by screen printing on the surface of the convex portion TB protruding upward from the main surface SM of the substrate KB.

[0028] In the screen printing method of this embodiment using the screen printing apparatus 1 configured as described above, the mesh screen 22, in which printing openings 22K for forming the printing pattern PPT are formed, is pressed against the surfaces of the protrusions TB with the squeegee 33 so that it conforms to the shape of the apexes of the protrusions TB, and the squeegee 33 is moved while maintaining this state, pushing the paste Pst out from the printing openings 22K toward the substrate KB and forming the printing pattern PPT on the apexes of the protrusions TB. In this method, the squeegee 33 elastically deforms to conform to the shape of the protrusions TB, causing the mesh screen 22 to conform to the shape of the apexes of the protrusions TB, so that the printing pattern PPT can be reliably formed on the curved surfaces of the protrusions TB.

[0029] As described above, according to the screen printing apparatus 1 (screen printing method) of this embodiment, the screen (mesh screen 22) having the printing openings 22K for forming the printing pattern PPT formed therein is pressed against the convex portion TB with the squeegee 33 to conform to the shape of the top of the convex portion TB, and by moving the squeegee 33 while maintaining this state, the paste Pst is pushed out from the printing openings 22K toward the substrate KB to form the printing pattern PPT on the top of the convex portion TB, thereby ensuring that the printing pattern PPT can be reliably formed on the surface of the convex portion TB protruding from the main surface SM of the substrate KB.

[0030] Although the embodiments of the present invention have been described above, the present invention is not limited to the above and various modifications are possible. For example, the shape of the protrusions TB of the substrate KB shown in the above embodiments is an example, and the shape of the protrusions TB is not necessarily limited to that shown in Figure 3 (Figure 11). Furthermore, the printing pattern PPT shown in the embodiments is an example, and is not limited to that shown in Figure 10. [Industrial Applicability]

[0031] A screen printing method and a screen printing device are provided that can form a print pattern on the surface of a substrate having protrusions protruding from its main surface by screen printing. [Explanation of symbols]

[0032] 1 Screen printing equipment 14 Print head drive unit (squeegee moving means) 22 Mesh screen (screen) 22K printing aperture 33 Squeegee 35 Backup member KB board SM main surface TB convex part PPT Print Pattern PST Paste

Claims

1. A screen printing method for forming a print pattern by screen printing on a surface of a convex portion protruding from a flat upper main surface of a substrate, the method comprising: a screen having printing openings for forming a printing pattern formed therein is pressed against the convex portions with a squeegee to conform to the shape of the tops of the convex portions, and the squeegee is moved while maintaining this state to extrude paste from the printing openings toward the substrate, thereby forming a printing pattern on the tops; A screen printing method, wherein when the squeegee is positioned on the convex portion while pressing the screen downward, the lower end of the squeegee is at a position lower than the height of the convex portion of the substrate and higher than the height of the main surface of the substrate.

2. The screen printing method according to claim 1 , wherein the squeegee elastically deforms to conform to the shape of the convex portions, thereby causing the screen to conform to the shape of the tops of the convex portions.

3. The screen printing method according to claim 1 or 2, wherein the squeegee is moved toward the convex portions from a state in which the main surface of the substrate and the convex portions are not in contact with the screen.

4. A screen printing apparatus for forming a print pattern by screen printing on a surface of a convex portion protruding from a main surface, which is a flat upper surface of a substrate, a screen having printing apertures formed therein for forming a printing pattern; a squeegee made of a plate-like member having a corner at its lower end; a squeegee moving means for pressing the screen against the convex portions with the corners of the squeegee to conform to the shape of the tops of the convex portions, and moving the squeegee while maintaining this state, thereby forcing the paste out from the printing openings toward the substrate and forming a printing pattern on the tops; Equipped with A screen printing device wherein, when the squeegee is positioned on the convex portion while pressing the screen downward, the lower end of the squeegee is at a position lower than the height of the convex portion of the substrate and higher than the height of the main surface of the substrate.

5. 5. The screen printing apparatus according to claim 4, further comprising a backup member that prevents the squeegee from being deformed in a warping direction when the corners of the squeegee are in contact with the screen.

6. The screen printing apparatus according to claim 4 or 5, wherein the squeegee is moved toward the convex portions from a state in which the main surface of the substrate and the convex portions are not in contact with the screen.

Images