Frame assembly, stencil, screen printing device and screen printing method

The present invention provides a frame assembly, which comprises a first frame and a second frame provided to surround the first frame. The first frame and the second frame are configured to support mesh fabric therebetween.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the priority of Chinese Patent Application No. 201510601647.4, filed on Sep. 18, 2015, the contents of which are incorporated herein in their entirety by reference.

FIELD OF THE INVENTION

The present invention relates to the field of display technology, and in particular, relates to a frame assembly, a stencil, a screen printing device, and a screen printing method.

BACKGROUND OF THE INVENTION

FIG. 1shows a structure of a touch panel including a visible area (VA)1and a black matrix (BM) area2. The VA1includes a sensing unit made of indium tin oxide (ITO), a touch signal sensed by the sensing unit is transmitted to a flexible printed circuit (FPC) through traces in the black matrix2, and further transmitted to an integrated circuit (IC) to be processed therein.

As shown inFIG. 2, a method for manufacturing the touch panel generally includes steps of: forming the sensing unit and the traces on a large glass substrate by an exposure process, a development process, and the like; cutting the large glass substrate to obtain a plurality of touch panels; and performing edge grinding, secondary screen printing and FPC bonding on each of the touch panels, so as to obtain a finished product. The secondary screen printing needs to be performed, because micro-cracks and notches will occur at an edge of each of the touch panels during the cutting and the edge grinding, damage the black matrix2, and degrade the appearance of a product. Thus, a blank margin3having a width of about 0.5 mm will be introduced to each edge of the touch panels after the cutting and the edge grinding, and secondary screen printing is performed on the blank margin3of each edge of the touch panels after the edge grinding so as to print the blank margin3to be black.

FIG. 3is a schematic diagram showing a screen printing device for secondary screen printing in the prior art, wherein, the peripheral blank area is a frame41, mesh fabric42is provided inside the frame41, the annular area in the mesh fabric42is an ink permeable area (also referred to as a “screen printing area”)43, when a scraper44is driven to scrape the mesh fabric42in the direction as shown by the arrow inFIG. 3, ink permeates through the ink permeable area43but cannot permeate through a non-screen-printing area. That is, ink is filled into a stencil before performing screen printing, and then the scraper is driven to scrape the mesh fabric to enable the ink in the ink permeable area43to permeate through the ink permeable area43, so that ink is printed onto the blank margin3on a surface of a touch panel.

Inventors of the present invention found that there exist at least the following technical problems in the prior art. On one hand, in the printing method of the above secondary screen printing, a large part of the portion, scraped by the scraper, of the mesh fabric does not belong to the ink permeable area. As a result, a large amount of ink remains on the large part of the mesh fabric, and less than 30% of the ink is printed onto the blank margin3on a surface of a touch panel. Thus, the large amount of ink is wasted, and the larger a size of the touch panel is, the lower a utilization ratio of the ink for screen printing is. On the other hand, in order to prevent the ink for secondary screen printing from contaminating the visible area1of a touch panel, a protection film for protecting the visible area1is generally attached to the touch panel to cover the visible area1before performing screen printing. Although the protection film is very thin, it results in a non-negligible segment difference (i.e., unevenness of a surface). The segment difference resulted from the protection film may cause the ink for screen printing in the ink permeable area43to have nonuniform thicknesses, wherein, the ink in an area close to the protection film has a large thickness, whereas the ink in an area far away from the protection film has a small thickness. In a severe case, “ink accumulation” and “ink overflow” may occur, and there is a risk that the scraper44may easily damage the mesh fabric42.

SUMMARY OF THE INVENTION

In view of the technical problems of ink waste and nonuniform thicknesses of scraped ink in the existing secondary screen printing, the present invention provides a frame assembly, a stencil, a screen printing device, and a screen printing method.

The present invention provides a frame assembly, including a first frame and a second frame provided to surround the first frame, wherein the first frame and the second frame are configured to support mesh fabric therebetween.

The present invention further provides a stencil, including the frame assembly as described above and mesh fabric provided between the first frame and the second frame, wherein, at least a part of the mesh fabric is an ink permeable area.

Optionally, the mesh fabric is made of polyester.

Optionally, the ink permeable area is provided to surround the first frame.

Optionally, the first frame is a rectangle.

The present invention further provides a screen printing device, including the stencil as described above and a scraper, wherein a width of the scraper is less than or equal to a width of a gap between the first frame and the second frame.

Optionally, the screen printing device is a screen printing device configured to perform secondary screen printing on a touch panel, the ink permeable area corresponds to a blank margin of the touch panel, a length and a width of the first frame are less than those of the touch panel, respectively, and a length and a width of the second frame are larger than those of the touch panel, respectively.

The present invention further provides a screen printing method, including a step of performing screen printing by the screen printing device as described above.

Optionally, the step of performing screen printing includes steps of:

providing a touch panel under the screen printing device, so that the ink permeable area corresponds to a blank margin of the touch panel; and

driving the scraper to scrape the ink permeable area.

In a case where screen printing is performed by the screen printing device according to the present invention, since the second frame is provided to surround the first frame and the mesh fabric is provided between the first frame and the second frame, an area of the mesh fabric can be reduced. When the screen printing device according to the present invention is in use, ink only needs to be coated onto a portion of the mesh fabric which is located between the first frame and the second frame, and it only needs to drive the scraper to move a lap on the mesh fabric between the first frame and the second frame to cause the ink in the ink permeable area to be printed onto a blank margin of a touch panel. In the present invention, the mesh fabric needs not to be provided inside the first frame, thus an amount of material of the mesh fabric is reduced; in addition, the first frame has a hollow structure and will not bring contamination to the visible area of a touch panel, thus a protection film for protecting the visible area can be omitted, thereby eliminating a segment difference resulted from the protection film, and eliminating a risk that the scraper easily damages the mesh fabric. Furthermore, since an inner side and an outer side of the mesh fabric are fixed to the first frame and the second frame, respectively, forces applied to the mesh fabric are more uniform. As a result, when the scraper scrapes the mesh fabric, the scraped ink has a uniform thickness, and the quality of screen printing and a utilization ratio of the ink are increased. The screen printing device according to the present invention is applicable to performing screen printing on a touch panel.

DESCRIPTION OF REFERENCE SIGNS

DETAILED DESCRIPTION OF THE EMBODIMENTS

To make those skilled in the art better understand the technical solutions of the present invention, the present invention will be described below in detail with reference to the accompanying drawings and the following embodiments.

First Embodiment

The present embodiment provides a frame assembly. As shown inFIG. 4, the frame assembly includes a first frame412and a second frame411provided to surround the first frame412. The first frame412and the second frame411are configured to support mesh fabric42therebetween.

That is, a frame41in the prior art is in a shape of “”. However, the frame assembly according to the present embodiment includes the first frame412and the second frame411provided to surround the first frame412, and thus is in a shape of “”. After mesh fabric42is provided between these two frames of the frame assembly, an inner side and an outer side of the mesh fabric42are fixed to the inner and outer frames (i.e., the first frame412and the second frame411), respectively, thus the forces applied to the mesh fabric42are more uniform.

Second Embodiment

The present embodiment provides a stencil, which includes the frame assembly according to the first embodiment and the mesh fabric42provided between the first frame412and the second frame411, wherein, at least a part of the mesh fabric42is an ink permeable area43.

That is, in a screen printing device in the prior art, a scraper44moves horizontally, as shown by the arrow inFIG. 3. In the present embodiment, however, as shown inFIG. 4, the inner side and the outer side of the mesh fabric42are fixed to the first frame412and the second frame411, respectively, and a scraper44A moves a lap between the first frame412and the second frame411along the arrow as shown inFIG. 4. The mesh fabric42is not provided inside the first frame412, and the first frame412has a hollow structure. Thus, no contamination will be brought to the visible area1of a touch panel, and a protection film for protecting the visible area1can be omitted. The forces applied to the mesh fabric42are more uniform, and when the scraper44A scrapes the mesh fabric42, ink permeates through the ink permeable area43uniformly.

Third Embodiment

The present embodiment provides a screen printing device. As shown inFIGS. 4 and 5, the screen printing device includes the stencil according to the second embodiment and a scraper44A, wherein a width of the scraper44A is less than or equal to a distance between the first frame412and the second frame411(i.e., is less than or equal to a width of a gap between the first frame412and the second frame411), such that the scraper44A can be driven to move between the first frame412and the second frame411along the arrow as shown inFIG. 4.

That is, when the screen printing device according to the present embodiment is in use, ink only needs to be introduced onto a portion of the mesh fabric42which is located between the first frame412and the second frame411, and then it only needs to drive the scraper44A to move a lap on the mesh fabric42between the first frame412and the second frame411to cause the ink in the ink permeable area43to be printed onto the blank margin3of a touch panel. As described above, the mesh fabric42needs not to be provided inside the first frame412, thus an amount of material of the mesh fabric42is reduced. In addition, the first frame412has a hollow structure and will not bring contamination to the visible area1of a touch panel, thus a protection film for protecting the visible area1can be omitted, thereby eliminating a segment difference resulted from the protection film, and eliminating a risk that the scraper44A easily damages the mesh fabric42. Furthermore, since the inner and outer sides of the mesh fabric42are fixed to the first frame412and the second frame411, respectively, the forces applied to the mesh fabric42are more uniform. As a result, when the scraper44A scrapes the mesh fabric42, the scraped ink has a uniform thickness, and the quality of screen printing and a utilization ratio of the ink are increased. The screen printing device according to the present embodiment is applicable to performing screen printing on various touch panels.

Optionally, the mesh fabric42is made of polyester.

That is, after the mesh fabric42is scraped by the scraper44A tens of thousands times, “ink accumulation” and “ink overflow” may occur. In order to avoid “ink accumulation” and “ink overflow,” the mesh fabric42provided between the first frame412and the second frame411may be replaced with a new one. Since the mesh fabric42is made of polyester, a service life of the mesh fabric42can be extended.

Optionally, the ink permeable area43is provided to surround the first frame412.

Optionally, the first frame412is a rectangle.

That is, as shown inFIG. 4, the ink permeable area43corresponds to the blank margin3on a surface of a touch panel. Generally, the ink permeable area43is a rectangular ring, and is provided to surround the first frame412. As a result, forces imposed on the inner side of the mesh fabric42can be uniform.

Optionally, the screen printing device is a screen printing device configured to perform secondary screen printing on a touch panel, and the ink permeable area43corresponds to the blank margin3of the touch panel; a length and a width of the first frame412are less than those of the touch panel, respectively, and a length and a width of the second frame411are larger than those of the touch panel, respectively. In other words, the length of the first frame412is less than that of the touch panel, the width of the first frame412is less than that of the touch panel, the length of the second frame411is larger than that of the touch panel, and the width of the second frame411is larger than that of the touch panel.

That is, the inner side of the mesh fabric42is fixed to the first frame412, and the outer side of the mesh fabric42is fixed to the second frame411. The ink permeable area43is provided in the middle of the mesh fabric42. With such configuration, the inner and outer sides of the mesh fabric42are subjected to uniform forces when the mesh fabric42is scraped by the scraper44A, causing ink to permeate through the ink permeable area43uniformly.

Obviously, many variations may be made to details in the foregoing embodiments. For example, a size of the first frame412or the second frame411may be adjusted according to a practical application, a width of the mesh fabric42or the ink permeable area43may be adjusted according to different products to which the present is applied, and the like.

Fourth Embodiment

The present embodiment provides a screen printing method, including a step of performing screen printing by the screen printing device as described above.

Optionally, the step of performing screen printing specifically includes steps of: providing a touch panel under the screen printing device, so that the ink permeable area43corresponds to the blank margin3of the touch panel (as shown inFIG. 5); and driving the scraper44A to scrape the ink permeable area43of the mesh fabric42. It is apparent to a person skilled in the art that, prior to the step of driving the scraper44A to scrape the ink permeable area43of the mesh fabric42, the screen printing method further includes a step of coating ink on the mesh fabric42.

When screen printing is to be performed, ink only needs to be introduced onto a portion of the mesh fabric42which is located between the first frame412and the second frame411, and then the scraper44A is driven to move a lap, along the frame assembly in the shape of “”, on the mesh fabric42between the first frame412and the second frame411, to cause the ink in the ink permeable area43to be printed onto the blank margin3on a surface of a touch panel.

It should be understood that, the foregoing embodiments are only exemplary embodiments used for explaining the principle of the present invention, but the present invention is not limited thereto. Various variations and improvements may be made by a person skilled in the art without departing from the protection scope of the present invention, and these variations and improvements also fall into the protection scope of the present invention.