Patent Application
20150287874
This application claims the benefit of Taiwan Patent Application No. 103205871, filed on Apr. 3, 2014, which is hereby incorporated by reference for all purposes as if fully set forth herein.
1. Technical Field
The present invention relates to a metal template structure, and more particularly, to a metal template having feeding guide portions additionally disposed on falling holes, so as to increase the aperture area during slurry falling, thereby obtaining optimal falling effect, and achieving high printing thickness of a finger electrode in a solar cell.
2. Related Art
Referring to
When printing a solar cell, the smaller width and larger thickness of a finger electrode on the substrate 30 result in higher solar energy conversion efficiency; however, the slurry 40 (for example, silver paste) for printing the solar cell electrode has high stickiness, and the falling hole 21 on the conventional metal template 20 has an aperture contacting the scraper the same size as an aperture close to the substrate 30, when the slurry 40 is scraped, the slurry 40 easily adheres to the aperture of the falling hole 21, so that the slurry cannot completely pass through the falling hole 21, resulting in incomplete penetrating or even incapability of penetrating, and therefore, ideal finger electrode printing thickness cannot be achieved, and the solar energy conversion efficiency is reduced.
Moreover, a ratio between the aperture of the falling hole 21 of the conventional metal template 20 and the thickness of the metal template 20 (about 20-50 μm) is less than or equal to 1.2, that is, the thickness of the metal template 20 cannot be greater than 1.2 times of the width of the aperture of the falling hole 21, which is mainly limited by a manufacturing method of processing falling holes on the metal template 20 at this stage, and in consideration that during a single layer structure printing process only using the metal template 20 as a printing template, printing quality is unstable because the metal template 20 lacks supporting, so that the falling holes 21 of the conventional metal template 20 has the limit on aspect ratio, the ratio between the aperture of the falling hole 21 and the thickness of the metal template 20 cannot be greater than 1.2, and it is difficult to improve the printing quality during actual application.
Accordingly, in order to overcome the above defects, the present invention is directed to solve the problem that a falling hole on a conventional metal template has an aperture contacting a scraper the same size as an aperture close to a substrate, the aperture width of the falling hole contacting the scraper is not large enough so that slurry easily adheres to the aperture of the falling hole, thereby resulting in incomplete falling or even incapability of penetrating, and therefore the ideal printing thickness cannot be achieved.
In order to achieve the above objective, the present invention discloses a metal template structure, which is characterized in that, a feeding guide portion extends upwards from an upper periphery of each falling hole, an aperture of the feeding guide portion is greater than an aperture of the falling hole, and the shape of a junction surface of an upper periphery of the feeding guide portion and an upper periphery of the falling hole may assume an inclined surface, a concave surface, or a right angle surface according to the feeding guide portion and different properties of slurry.
The present invention has the advantage that, by using the feeding guide portions having greater aperture, when slurry is scraped, more slurry falls into the falling holes, so as to keep the optimal printing thickness; moreover, the increased feeding guide portion increases the thickness of the metal template, so that the ratio between the aperture of the falling hole and the thickness of the metal template is greater than 1.2, thereby achieving better printing quality.
The disclosure will become more fully understood from the detailed description given herein below for illustration only and thus are not limitative of the disclosure, and wherein:
Detailed content and technical descriptions of the present invention are further illustrated through embodiments, but it should he understood that, the embodiments are only described as examples, and are not intended to limit the present invention.
Referring to
During implementation, a surface of the metal template 200 provided with the feeding guide portion 200 is placed upwards (the upper surface is generally referred to as a scraper surface), a substrate 300 is placed under the metal template 200 (the lower surface is generally referred to as an object contact surface), slurry 400 is placed in the range of the supporting stainless wire cloth 120 defined by the frame 110, and a scraper is used to scrape the slurry 400 to the feeding guide portion 220 on the metal template 200, so that the slurry 400 flows to the falling hole 210 through the feeding guide portion 220, and the slurry 400 forms a printing image on the substrate 300 through the arrangement of the falling holes 210.
Referring to FIG, 5,
Further, feeding apertures X2 of the feeding guide portions 220 are all greater than falling apertures X1 of the falling holes 210, so that when the slurry 400 is scraped to the feeding aperture X2, because the feeding aperture X2 is greater, the area for penetrating is increased, and during implementation, more slurry 400 is easily scraped to the feeding guide portions 220, and the feeding guide portions 220 guides the slurry 400 into the falling holes 210, thereby improving the penetrating rate of the slurry 400, so as to achieve the optimal printing line thickness.
During implementation, a material for forming the feeding guide portions 220 may be a metal material of the metal template 200 through extension or may be an additional polymer material, and a method for forming the falling guide portions 220 is not limited to laser processing, etching, electroforming, or forming by jointing the polymer material or another heterogeneous material. By forming the feeding guide portions 220, when being provided with the falling holes 210 having the same falling aperture X1, the metal template 200 in the present invention has increased thickness (about 5-50 μm), and the thicker metal template 200 has better stability; therefore, the optimal printing quality may be achieved during implementation because of the good stability.
Furthermore, referring to
Furthermore, a protrusion 260 is disposed on the inner side wall of each of the falling holes, and a bottom end of the protrusion 260 extends to a bottom of the falling hole 210 (as shown in
Therefore, the present invention adds the design of the feeding guide portions 220, which increases the penetrating rate of the slurry 400 flowing to the falling holes 210, so that when the slurry is scraped, more slurry 400 falls into the falling holes 210, thereby achieving the optimal printing line thickness. Moreover, because of the feeding guide portions 220, the falling holes 210, when having the same falling aperture X1, increase the thickness of the metal template 200, the thicker metal template 200 has better stability, and good stability may achieve better printing quality.
The present invention is disclosed through preferred embodiments in the foregoing text, however, those skilled in the art should understand that the embodiments are merely for the purpose of describing the present invention, but are not intended to limit the present invention. It should be noted that, equivalent variations and replacements made to the above embodiments shall fall within the scope of the present invention as specified in the following claim.
| Number | Date | Country | Kind |
|---|---|---|---|
| 103205871 | Apr 2014 | TW | national |
