TWI558573B - Printing screen and solar cell - Google Patents

Description

Printing screen and solar cell

This invention relates to a printing technique and, more particularly, to a printing screen.

At present, in the manufacturing process of a solar cell, the front and back collectors of the solar cell are usually fabricated by screen printing, wherein the collector may include a bus bar and a finger. Therefore, the printing of the collector of the solar cell, particularly the front collector, is very important for the photoelectric conversion efficiency of the solar cell.

In general, the main factors affecting the printing quality of the electrodes are screens, doctor blades, conductive pastes, and printing parameters. Since the conductive paste is exposed to the air during printing, and the long-term printing of the conductive paste, the solvent of the conductive paste volatilizes with time, and the viscosity thereof gradually increases. As a result, the conductive paste is likely to be difficult to be inked due to being too dry, thereby causing poorness in electrode printing, resulting in poor printing quality. In addition, the incompleteness or unevenness of the knives of the printing blade and the inaccuracy of the conductive paste also affect the printing quality.

Therefore, with the development trend of printing thinning, it is more and more important to grasp the printing quality of the collector.

Accordingly, it is an object of the present invention to provide a printing screen which provides an indicator during continuous printing for an online worker to instantly determine the viscosity of the printing paste to avoid a continuous large amount due to excessive viscosity of the slurry. The quality of electrode printing is not good, which can effectively improve the electrical output efficiency of solar cells.

Another object of the present invention is to provide a printing screen and a solar cell, which can provide an indicator for the online staff to monitor the overall printing quality in real time without affecting the overall printing appearance, thereby not only enabling the online staff Instantly improve the printing process, this indicator can be used as an indicator of whether the online worker slurry or printing blade needs to be replaced.

It is yet another object of the present invention to provide a printing screen that enhances the stability and yield of the printing process.

According to the above object of the invention, a printing screen is proposed. This printing screen contains a mesh and a barrier layer. The barrier layer is provided on the mesh. The barrier layer includes at least two first barriers and at least one second barrier. Each of the first blocking portions has a plurality of first opening portions, wherein the first opening portions are parallel to each other and spaced apart in the first direction, and each of the first opening portions extends in a second direction different from the first direction. The at least one second blocking portion is disposed between the at least two first blocking portions and extends in the first direction, and has a plurality of second openings. The second openings are parallel to each other and spaced apart in the first direction, and the first width of each of the first openings is greater than or equal to the second width of each of the second openings, and the second widths are different.

According to an embodiment of the invention, the second opening portion is arranged in a small and large order according to the size of the second width.

According to another embodiment of the present invention, the second opening portion is arranged in a large and small order according to the size of the second width.

According to still another embodiment of the present invention, the second width is less than or equal to 80 μm .

According to still another embodiment of the present invention, the second opening portion is not connected to the first opening portion.

According to still another embodiment of the present invention, the second opening portion is connected to the first opening portion.

According to still another embodiment of the present invention, the first opening portion is connected to the second blocking portion.

According to still another embodiment of the present invention, the first opening portion and the second blocking portion are not connected.

According to still another embodiment of the present invention, the barrier layer further includes at least one third opening portion disposed between the first blocking portion and extending along the first direction, wherein the first opening portion is connected to the third opening portion. And the second blocking portion is in the third opening portion.

According to the above object of the present invention, a solar cell is further proposed. The solar cell includes a substrate, a plurality of first electrodes, a plurality of first spaces, and a plurality of second electrodes. The first electrodes are disposed on the substrate and are parallel to each other and spaced apart in the first direction. The first space intersects the first electrode and is arranged in a second direction different from the first direction. The second electrode is located in at least one of the first spaces, wherein the second electrodes are parallel to each other and spaced apart in the first direction, and the first width of each of the first electrodes is greater than or equal to the second width of each of the second electrodes, And these second widths are different.

According to an embodiment of the invention, the second electrodes are arranged in order from small to large according to the second width.

According to another embodiment of the present invention, the second electrodes are sequentially arranged from large to small according to the size of the second width.

According to still another embodiment of the present invention, the second width of the second electrode is less than or equal to 80 μm.

According to still another embodiment of the present invention, the second electrode is not connected to the first electrode.

According to still another embodiment of the present invention, the second electrode is connected to the first electrode.

According to still another embodiment of the present invention, the solar cell further includes a plurality of third electrodes located in the first space, wherein the third electrodes extend in the first direction, and the third electrodes and at least one side of the first electrodes And wherein the third electrode in the at least one of the first spaces further comprises a hollow region surrounding the second electrode.

100a‧‧‧Printing version

100b‧‧‧Printing version

100c‧‧‧Printing version

102‧‧‧Mesh

104a‧‧‧Block

104b‧‧‧Block

104c‧‧‧Block

106‧‧‧First barrier

108‧‧‧First opening

110a‧‧‧second barrier

110b‧‧‧second barrier

110c‧‧‧second barrier

112‧‧‧second opening

114‧‧‧second opening

116‧‧‧second opening

118‧‧‧second opening

120‧‧‧second opening

122‧‧‧second opening

124‧‧‧First direction

126‧‧‧second direction

128a‧‧‧3rd opening

128b‧‧‧ third opening

130‧‧‧second opening

200‧‧‧ finger electrode

202‧‧‧Area

204‧‧‧ indicators

206‧‧‧ indicators

208‧‧‧ indicators

210‧‧‧ indicators

212‧‧‧ indicators

214‧‧‧ indicators

216‧‧‧Concurrent electrode

218a‧‧‧Concurrent electrode

218b‧‧‧ bus electrode

220‧‧‧Unprinted area

222‧‧‧ indicators

224‧‧‧Substrate

226‧‧‧ first direction

228‧‧‧second direction

The above and other objects, features, advantages and embodiments of the present invention will become more <RTIgt; See the schematic.

2 is a partially enlarged schematic view showing a printing screen according to an embodiment of the present invention.

3A and 3B are diagrams illustrating the use of an embodiment of the present invention. A schematic diagram of a screen printing process performed by a printing screen.

Figure 4 is a top plan view of a printing screen according to another embodiment of the present invention.

Figure 5 is a partially enlarged schematic view showing a printing screen according to another embodiment of the present invention.

Figure 6 is a top plan view showing one of the screen printing structures obtained by using a printing screen of another embodiment of the present invention.

Figure 7 is a top plan view of a printing screen according to still another embodiment of the present invention.

Figure 8 is a top plan view showing a screen printing structure obtained by using a printing screen of still another embodiment of the present invention.

In view of the change in the viscosity of the slurry or the unevenness of the blade surface in the conventional screen printing process, the fullness of the printed structure is not good, resulting in poor printing quality. In this case, several kinds of screen designs are proposed to provide indicators for continuous printing, so that the online staff can instantly judge the viscosity of the printing paste and the flatness of the blade surface of the blade, thereby achieving the goal of improving the printing quality. The performance of solar cells.

Please refer to FIG. 1 and FIG. 2 , which are respectively a schematic top view and a partially enlarged schematic view of a printing screen according to an embodiment of the present invention. In the present embodiment, the printing screen 100a can be used to print the front collector of a solar cell. The printing screen 100a mainly comprises a mesh 102 and a barrier layer 104a. The mesh 102 is woven from a plurality of thin wires. In some embodiments, the mesh 102 is woven from metal wires to increase the printing mesh. The life of the version 100a. The barrier layer 104a is disposed on the mesh 102. In an exemplary embodiment, a portion of the barrier layer 104a is filled into the mesh 102 to bond with the mesh 102 and the other portion extends downwardly from the mesh 102. Barrier layer 104a is typically an emulsion layer. In an exemplary embodiment, the material of the barrier layer 104a is a negative photoresist.

In some embodiments, the barrier layer 104a includes at least two first barriers 106 and at least one second barriers 110a. In an exemplary embodiment, as shown in FIG. 1, the barrier layer 104a includes three first blocking portions 106 and two first blocking portions 110a. These first blocking portions 106 are spaced apart along the second direction 126. Moreover, these first blocking portions 106 may be parallel to each other. Additionally, each of the first barriers 106 can extend along the first direction 124. The second blocking portion 110a is also aligned along the second direction 126 and disposed between the adjacent two first blocking portions 106. Moreover, the second blocking portions 110a may be parallel to each other. Further, each of the second blocking portions 110a may extend along the first direction 124.

Each of the first blocking portions 106 has a plurality of first openings 108. These first openings 108 can be used, for example, to form finger electrodes in the front side of the solar cell. In each of the first blocking portions 106, the first opening portions 108 are parallel to each other, and each of the first opening portions 108 is spaced apart in the first direction 124. Further, the first opening portions 108 extend toward the second direction 126. The first direction 124 is different from the second direction 126. In some exemplary examples, the first direction 124 is perpendicular to the second direction 126. In this embodiment, the first opening portion 108 is connected to the second blocking portion 110a.

On the other hand, the second blocking portion 110a has a plurality of second opening portions 112, 114, 116, 118, 120, and 122. In this embodiment, the second The blocking portion 110a has six second opening portions 112, 114, 116, 118, 120 and 122. However, this is for illustrative purposes only and is not intended to limit the case. The number of the second opening portions of the second blocking portion 110a may be Adjusted according to the needs of observation. In addition, in the present case, each of the second blocking portions 110a may be provided with the second opening portions 112, 114, 116, 118, 120, and 122, but as shown in FIG. 1, only one second blocking is required. The second opening portions 112, 114, 116, 118, 120, and 122 may be provided in the portion 110a. Moreover, the second opening portions 112, 114, 116, 118, 120, and 122, except for the adjustable number, may be disposed not only in the partial region of the second blocking portion 110a as shown in FIG. 1, but It is arranged in the entire second blocking portion 110a along the first direction 124.

In the present embodiment, neither of the second openings 112, 114, 116, 118, 120, and 122 is connected to the first opening 108. In the second blocking portion 110a, the second opening portions 112, 114, 116, 118, 120, and 122 are parallel to each other, and each of the second opening portions 112, 114, 116, 118, 120, and 122 is along the first direction 124. Arranged at intervals. In an exemplary embodiment, the second openings 112, 114, 116, 118, 120, and 122 extend toward the second direction 126. In the printing screen 100a, each of the first openings 108 has substantially the same first width, and each of the second openings 112, 114, 116, 118, 120 and 122 has a second width different from each other. In an exemplary embodiment, the second width of the second openings 112, 114, 116, 118, 120, and 122 is less than or equal to 80 μm .

In some embodiments, the second width of the second openings 112, 114, 116, 118, 120, and 122 can be increased by a fixed gap. This fixed gap can be, for example, from 1 μm to 10 μm . In other embodiments, the second width of the second openings 112, 114, 116, 118, 120, and 122 may be increased by a different difference. As shown in FIGS. 1 and 2, in the second blocking portion 110a, the second opening portions 112, 114, 116, 118, 120, and 122 follow the first width 124 in accordance with the respective second widths. , arranged in small and large order. In other embodiments, the second openings 112, 114, 116, 118, 120, and 122 may be arranged in a large and small order along the first direction 124 according to the size of the respective second width.

Moreover, in some exemplary examples, the first width of the first opening 108 is greater than the second width of all of the second openings 112, 114, 116, 118, 120, and 122. In other exemplary embodiments, the first width of the first opening portion 108 may be equal to the second width of the second opening portion 112, 114, 116, 118, 120, and 122, that is, the second opening portion 122. For example, the second width of the second opening portion 122 is substantially equal to the first width of the first opening portion 108, and the second width of the second opening portion 120 is smaller than the second width of the second opening portion 122 by 5 μm . The second width of the second opening portion 118 is smaller than the second width of the second opening portion 120 by 5 μm , and the second width of the second opening portion 116 is smaller than the second width of the second opening portion 118 by 5 μm . the second portion 114 of width smaller than the second width of 5 μ m of the second opening portion 116, and the second width of the second opening portion 112 of the small, 5 μ m width than the second portion 114 of the second opening.

Please refer to FIG. 1 and FIG. 3A and FIG. 3B simultaneously, wherein FIG. 3A and FIG. 3B are schematic diagrams showing a screen printing process performed by using a printing screen according to an embodiment of the present invention. The printing screen 100a can be, for example, Used in the screen printing process of the electrodes of solar cells. When the screen printing process is performed by the printing screen 100a, the screen printing 100a can be used for the first printing, and the other printing screen (not shown) can be used for the second printing. After the first printing is performed by the printing screen 100a, the first electrode, for example, the finger electrode 200, is formed on the substrate 224 by the slurry dropped from the first opening 108. These finger electrodes 200 are parallel to each other and are spaced apart in the first direction 226. Furthermore, these finger electrodes 200 extend in a second direction 228. The first direction 226 is different from the second direction 228. In some exemplary examples, the first direction 226 is perpendicular to the second direction 228. Since each of the first openings 108 in the printing screen 100a has substantially the same first width, the correspondingly formed finger electrodes 200 have substantially the same width. As shown in FIG. 3A, a plurality of first spaces, that is, regions 202 are formed on the substrate 224 at the second blocking portion 110a corresponding to the printing screen 100a. These regions 202 are aligned along the second direction 228 and intersect the finger electrodes 200. These regions 202 can be parallel to one another and each second barrier 110a can extend along the first direction 226.

At the same time, the slurry falling from the second opening portions 112, 114, 116, 118, 120, and 122 respectively forms a plurality of indicators 204, 206, 208, 210 which can be regarded as the second electrodes on the substrate 224, 212 and 214, as shown in Figure 3A. These indicators 204, 206, 208, 210, 212, and 214 can be located in at least one region 202. These indicators 204, 206, 208, 210, 212, and 214 are parallel to each other and are spaced apart along the first direction 226. Moreover, these indicators 204, 206, 208, 210, 212, and 214 extend toward the second direction 228. Additionally, the indicators 204, 206, 208, 210, 212, and 214 may be disconnected from the finger electrodes 200. Due to the second opening portions 112, 114, 116, 118, The second widths of 120 and 122 have different sizes, so the corresponding formed indicators 204, 206, 208, 210, 212, and 214 have different widths from each other. In an exemplary embodiment, the width of each of the finger electrodes 200 is greater than or equal to the width of each of the indicators 204, 206, 208, 210, 212, and 214. The width of the indicators 204, 206, 208, 210, 212, and 214 can be, for example, less than or equal to 80 [mu]m. Since the second widths of the second openings 112, 114, 116, 118, 120, and 122 are different from each other, the judgment can be monitored by observing the structures of the corresponding formed indicators 204, 206, 208, 210, 212, and 214. Whether the ink discharge property of the slurry is deteriorated or not, and the viscosity state of the slurry is judged.

In some embodiments, the indicators 204, 206, 208, 210, 212, and 214 are arranged in a small, large order along the first direction 226 in accordance with the respective widths. In other embodiments, the indicators 204, 206, 208, 210, 212, and 214 may be arranged in a large and small order along the first direction 226 according to the size of the respective widths.

For example, when the second width of the second opening portion 122 is equal to the first width of the first opening portion 108, and the second width of the second opening portions 120, 118, 116, 114, and 112 is decreased by a small 5 μm difference When the new slurry can be discharged from the second opening portion 116, but the index 212 formed by the slurry dropped by the second opening portion 120 during mass printing has a structurally insufficient condition, the viscosity of the slurry is indicated. There may be an upper limit, and it may be necessary to replace the new slurry or adjust the viscosity of the slurry. Therefore, by using the second openings 112, 114, 116, 118, 120 and 122 of the printing screen 100a, the structures of the correspondingly formed indicators 204, 206, 208, 210, 212 and 214 can be observed during the printing process. This allows the online staff to judge the viscosity of the printing paste at any time. In other words, the judgment result can be used as a reference for replacing the new slurry or adjusting the viscosity of the slurry. Therefore, the application of the printing screen 100a not only avoids the poor printing quality due to the excessive viscosity of the slurry, but also increases the stability and yield of the printing process, and avoids the solar acid's poor saturation of the collector structure. The electrical efficiency of the battery is reduced.

After the first printing is completed by the printing screen 100a, the second printing can be performed by using another printing screen having an opening corresponding to the area of the second blocking portion 110a of the printing screen 100a. After the second printing, the bus electrode 216 is formed on the region 202 corresponding to the second barrier portion 110a of the printing screen 100a by printing the paste under the opening tribe of the screen, as shown in Fig. 3B. The finger electrodes 200 are all connected to the bus electrode 216. In addition, the bus electrodes 216 can cover the indicators 204, 206, 208, 210, 212, and 214 formed by the first pass, and the presence of the indicators 204, 206, 208, 210, 212, and 214 is not readily apparent in appearance. Therefore, the present embodiment can achieve the purpose of monitoring the viscosity of the printing paste in real time under the influence of reducing the appearance of the solar cell.

The above embodiment is a dual printing method or a double printing method. However, the technology of the present invention can also be applied to a single printing technique. Please refer to FIG. 4 and FIG. 5 , which are respectively a top view and a partially enlarged schematic view of a printing screen according to another embodiment of the present invention. In the present embodiment, the printing screen 100b is substantially the same as the printing screen 100a of the above embodiment, and the difference is that the barrier layer 104b of the printing screen 100b further has at least a third opening, such as a third opening. Parts 128a and 128b. And at least one second The blocking portion 110b is located in the third opening portion 128a. In the embodiment shown in Fig. 4, only the second blocking portion 110b is provided in the third opening portion 128a, and the second blocking portion 110b is not provided in the other third opening portion 128b. However, the second blocking portion 110b may be provided in the third opening portion 128b according to the judgment request.

As shown in FIG. 4, in the printing screen 100b, the position of the third opening portion 128 corresponds to the second blocking portion 110a of the printing screen 100a, and thus the third opening portion 128 is provided in the adjacent first blocking portion. Between 106, and arranged along the second direction 126. Moreover, the third opening portions 128 may be parallel to each other, and each of the third opening portions 128 may extend along the first direction 124. Further, the third opening portion 128 is connected to the first opening portion 108. As shown in FIG. 5, the second blocking portion 110b is located in the third opening portion 128, and the plurality of second opening portions 112, 114, 116, 118, 120, and 122 are also located in the second blocking portion 110b. Moreover, the second blocking portion 110b blocks the second opening portions 112, 114, 116, 118, 120 and 122 and the third opening portion 128, thus causing the second opening portions 112, 114, 116, 118, 120 and 122 and The third openings 128 are not connected to each other. In addition, the third opening portion 128 also blocks the first opening portion 108 and the second blocking portion 110b such that the first opening portion 108 and the second blocking portion 110b are not connected.

With such a layout design, the printing of the collector of the solar cell can be performed in a single printing manner using the printing screen 100b. Referring to FIG. 6, a top view of a screen printing structure obtained by using a printing screen according to another embodiment of the present invention is shown. When the screen printing process is performed by the printing screen 100b, as in the above embodiment, it falls from the first opening portion 108. The slurry forms a first electrode, such as finger electrode 200, on substrate 224, and the slurry falling from third openings 128a and 128b forms a third electrode, such as bus electrodes 218a and 218b, on substrate 224, respectively. The bus electrodes 218a and 218b are aligned along the second direction 228, the bus electrodes 218a and 218b are parallel to each other, and each of the bus electrodes 218a and 218b can extend along the first direction 226. Further, the bus electrodes 218a and 218b are connected to at least one side of the finger electrodes 200. At the same time, as in the above embodiment, the slurry dropped by the second openings 112, 114, 116, 118, 120, and 122 also forms a plurality of indicators 204, 206 which can be regarded as the second electrodes on the substrate 224, respectively. , 208, 210, 212, and 214, as shown in FIG. On the other hand, the second blocking portion 110b correspondingly forms a hollow region, that is, an unprinted region 220, in the bus electrode 218a. The unprinted area 220 surrounds the indicators 204, 206, 208, 210, 212, and 214, so that the line staff can determine the viscosity of the slurry by observing the structures of the indicators 204, 206, 208, 210, 212, and 214. By using the second opening portions 112, 114, 116, 118, 120, and 122 to have a second width and a different size, the structure of the corresponding formed indicators 204, 206, 208, 210, 212, and 214 can be observed. To monitor whether the ink discharge of the slurry is deteriorated, and then determine the viscosity of the slurry.

In the present embodiment, since the printing screen 100b is designed as a single printing type, and the second blocking portion 110b is provided in the third opening portion 128a corresponding to the bus electrode 218a, the printing screen 100b is used. After the screen printing, the formed bus electrode 218a is different from the other bus electrode 218b. The bus electrode 218a also has an unprinted area 220 and Indicators 204, 206, 208, 210, 212, and 214. Although it can be seen in the printing results that the bus electrode 218a additionally has an unprinted area 220 and indicators 204, 206, 208, 210, 212 and 214 instead of a strip-like structure such as the bus electrode 218b, due to the subsequent solar energy In the string soldering process of the battery, a ribbon is used to cover the bus electrodes 218a and 218b, so that the formed solar cell module does not see the unprinted area 220 and the indicators 204, 206 from the appearance. The presence of 208, 210, 212 and 214. Therefore, the printing screen 100b of the present embodiment can also be applied to the screen printing process to instantly monitor the viscosity of the printing paste without considering the appearance factor of the solar cell.

The printed screen version of this case can also be designed to monitor the overall print quality. Please refer to FIG. 7 , which is a top plan view of a printing screen according to still another embodiment of the present invention. In the present embodiment, the printing screen 100c is substantially the same as the printing screen 100a of the above embodiment, and the difference is that the second opening 130 in the second blocking portion 110c of the barrier layer 104c of the printing screen 100c is different. Corresponding to the position of the first opening portion 108 of the adjacent first blocking portion 106, and corresponding to the corresponding first opening portion 108.

As shown in Fig. 7, in the printing screen 100c, the second openings 130 are arranged in the second blocking portion 110c along the first direction 124. Moreover, the second opening portions 130 are respectively connected to the first opening portions 108 of the adjacent first blocking portions 106. That is, the opposite ends of each of the second opening portions 130 are respectively in contact with the first opening portions 108 of the two first blocking portions 106 located on opposite sides thereof and adjacent thereto. In some embodiments, each of the second openings 130 has the same second width. In other embodiments, the second openings 130 have different second widths, such as a second width that increases in a fixed or unfixed gap. Further, the second width of each of the second opening portions 130 is smaller than the first width of the first opening portion 108. In an exemplary example, when the first width of the first opening portion 108 is 40 μm , the second width of the second opening portion 130 may be 15 μm .

In some embodiments, each of the first openings 108 is correspondingly connected to a second opening 130. In such an embodiment, the monitoring area of the slurry viscosity is distributed throughout each of the first openings 108, so that the printed areas of all of the first openings 108 can be completely monitored. Of course, in other embodiments, only a portion of the first opening portion 108 has a correspondingly connected second opening portion 130 for monitoring the print quality from a partial monitoring manner of the printed area.

Figure 8 is a top plan view showing a screen printing structure obtained by using a printing screen of still another embodiment of the present invention. When the screen printing process is performed by the printing screen 100c, as in the above embodiment, the slurry dropped from the first opening 108 forms a first electrode, such as the finger electrode 200, on the substrate 224. The slurry falling from the second opening portion 130 forms an index 222 on the substrate 224 which can be regarded as the second electrode. Further, the indicator 222 is connected to the finger electrode 200. By designing that the second opening 130 of the printing screen 100c has a second width smaller than the first width of the first opening 108, the structure of the index 222 formed corresponding to the second opening 130 can be observed. The monitoring determines whether the ink discharge property of the slurry is deteriorated, and further determines the viscosity state of the slurry, and can also monitor whether the printing blade has a defect of unevenness.

It can be seen from the above embodiments that one of the advantages of the present invention is that the printing screen of the present invention can provide an index during continuous printing for the online staff to instantly judge the viscosity of the printing paste, thereby avoiding the excessive viscosity of the slurry. The quality of the continuous large number of electrode printing is poor, and the electrical output efficiency of the solar cell can be effectively improved.

It can be seen from the above embodiments that another advantage of the present invention is that the printing screen of the present invention can provide an indicator for the online staff to monitor the overall printing quality in real time without affecting the overall printing appearance. Online staff can instantly improve the printing process, and this indicator can be used as an indicator of whether the online staff slurry or printing blade needs to be replaced. Therefore, the use of the printing screen of the invention can effectively improve the stability and yield of the printing process.

While the present invention has been described above by way of example, it is not intended to be construed as a limitation of the scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

100a‧‧‧Printing version

106‧‧‧First barrier

108‧‧‧First opening

110a‧‧‧second barrier

112‧‧‧second opening

114‧‧‧second opening

116‧‧‧second opening

118‧‧‧second opening

120‧‧‧second opening

122‧‧‧second opening

Claims (16)

A printing screen comprising: a mesh; and a barrier layer disposed on the mesh, wherein the barrier layer comprises: at least two first blocking portions, wherein each of the first blocking portions has a plurality of first portions An opening portion, wherein the first opening portions are parallel to each other and spaced apart along a first direction, and each of the first opening portions extends in a second direction different from the first direction; and at least one second blocking a portion, disposed between the first blocking portions and extending along the first direction, and having a plurality of second openings, wherein the second openings are parallel to each other and spaced along the first direction, each of the One of the first openings has a first width greater than or equal to a second width of each of the second openings, and the second widths are different. The printing screen of claim 1, wherein the second openings are arranged in a small and large order according to the size of the second widths. The printing screen of claim 1, wherein the second openings are arranged in a large and small order according to the size of the second widths. The printing screen of claim 1, wherein the second widths are less than or equal to 80 μm . The printing screen of claim 1, wherein the second openings are not connected to the first openings. The printing screen of claim 1, wherein the second openings are respectively connected to the first openings. The printing screen of claim 1, wherein the first openings are connected to the at least one second blocking portion. The printing screen of claim 1, wherein the first openings Not connected to the at least one second blocking portion. The printing screen according to claim 1, wherein the barrier layer further has at least one third opening portion disposed between the first blocking portions and extending along the first direction, the first opening portions and the at least A third opening is connected, and the at least one second blocking portion is located in the at least one third opening. A solar cell comprising: a substrate; a plurality of first electrodes disposed on the substrate and arranged parallel to each other and spaced apart along a first direction; a plurality of first spaces, the first spaces and the first portions The electrodes intersect each other and are arranged in a second direction different from the first direction; and the plurality of second electrodes are located in at least one of the first spaces, wherein the second electrodes are parallel to each other and along the first The first width of each of the first electrodes is greater than or equal to a second width of each of the second electrodes, and the second widths are different. The solar cell of claim 10, wherein the second electrodes are arranged in order from small to large according to the second width. The solar cell of claim 10, wherein the second electrodes are sequentially arranged from large to small according to the size of the second widths. The solar cell of claim 10, wherein the second widths of the second electrodes are less than or equal to 80 μm. The solar cell of claim 10, wherein the second electrodes are not connected to the first electrodes. The solar cell of claim 10, wherein the second electrodes are connected to the first electrodes. The solar cell as claimed in claim 10, further comprising a plurality of a third electrode is disposed in the first spaces, wherein the third electrodes extend along the first direction, and the third electrodes are in contact with at least one of the first electrodes, wherein the first spaces are located The third electrode of the at least one of the third electrodes further includes a hollowed out region surrounding the second electrodes.