CN216993523U

CN216993523U - Doctor blade for paste printing

Info

Publication number: CN216993523U
Application number: CN202220167416.2U
Authority: CN
Inventors: 王海峰
Original assignee: Heli Photovoltaic Technology Shanghai Co ltd
Current assignee: Heli Photovoltaic Technology Shanghai Co ltd
Priority date: 2022-01-21
Filing date: 2022-01-21
Publication date: 2022-07-19
Anticipated expiration: 2032-01-21

Abstract

The utility model relates to a squeegee for paste printing, the squeegee (1) comprising a connection member (10), a main squeegee (20) fixed to the connection member (10) and at least one isolation barrier squeegee (30) fixed to the main squeegee (20), the main squeegee (20) comprising a push side (21) for pushing paste forward and being connected to a printing machine via the connection member (10), the at least one isolation barrier squeegee (30) being fixed to the push side (21) of the main squeegee (20) and extending in a printing direction (F) to allow at least two different pastes to be printed onto an object to be printed in isolation from each other. By means of the scraping glue (1), at least two different sizing agents are allowed to be printed on the same object to be printed, so that at least two different sizing agents can be accurately compared and tested, and errors caused by printing on different objects to be printed are avoided.

Description

Doctor blade for paste printing

Technical Field

The utility model relates to the field of paste printing, in particular to a frictioning for paste printing.

Background

In the field of photovoltaic solar power generation, conductive silver wires are required to be printed on a solar cell sheet for collecting current. Therefore, the silver paste has a significant influence on the energy conversion efficiency and economic cost of the solar cell sheet. In order to test the performance of the silver paste, the silver paste is generally printed on a silicon wafer used for preparing a solar cell by a screen printing technique, and then the line width and the resistance of the printed silver line are measured.

In the process of screen printing, the frictioning pushes the silver paste placed on the printing screen plate from one end to the other end of the printing screen plate under the driving of the printing machine, the frictioning applies a certain pressure on the printing screen plate, and the silver paste is extruded to a silicon wafer below the printing screen plate through meshes of the printing screen plate, so that silver wires are printed on the silicon wafer.

The currently used squeegees can only print one slurry at a time. However, since there is a difference in film thickness and thus different brightness between different silicon wafers, this causes a significant difference in test results obtained when measuring the line width of silver lines using a 3D microscope, the higher the brightness, the larger the measured line width. Therefore, the test results obtained when the same paste is printed on different silicon wafers are different, which is misleading to test judgment.

In order to reduce the slurry test error caused by the difference between silicon wafers, it is desirable to print at least two different slurries on the same silicon wafer so as to perform a comparative test on the different slurries, thereby developing a slurry with excellent performance.

SUMMERY OF THE UTILITY MODEL

The object of the present invention is to solve at least one aspect of the above-mentioned problems existing in the prior art.

According to the present invention, there is provided a squeegee for paste printing characterized in that the squeegee comprises a connection member, a main squeegee fixed to the connection member and at least one isolation barrier squeegee fixed to the main squeegee, the main squeegee comprising a push side for pushing paste forward and being connected to a printing machine via the connection member, the at least one isolation barrier squeegee being fixed to the push side of the main squeegee and extending in a printing direction to allow at least two different pastes to be printed onto an object to be printed in isolation from each other. Therefore, at least two different sizing agents can be printed on the same object to be printed, so that the different sizing agents can be compared and tested, and the sizing agent with excellent performance can be developed.

According to a preferred embodiment of the utility model, the pushing side comprises a first edge and a second edge opposite to the first edge, the first edge forming a printing edge for abutting against the printing screen, the at least one isolation barrier squeegee comprising a first face extending from the pushing side adjacent to the printing edge, the first face being offset with respect to the printing edge by a distance towards the second edge. Preferably, the distance is not more than 1 mm. This prevents the isolation barrier squeegee from damaging the printing screen, but still allows it to effectively isolate different pastes.

According to a preferred embodiment of the present invention, a second face of the isolation barrier squeegee fixed to the main squeegee forms an angle with the first face of the isolation barrier squeegee, the angle corresponding to an angle of the push side face of the main squeegee with respect to the printing direction. This allows the first side of the isolation barrier squeegee to be reliably held against the printing screen. For example, the included angle is 55 °.

According to a preferred embodiment of the utility model, the hardness of the isolation barrier squeegee is less than the hardness of the main squeegee. This prevents the isolation barrier squeegee from damaging the printing screen. Preferably, the isolation barrier frictioning has a shore hardness of 55-75 degrees and/or the primary frictioning has a shore hardness of 70-80 degrees.

According to a preferred embodiment of the present invention, the squeegee includes a separation blocking squeegee fixed to an intermediate position of the main squeegee in a width direction of the main squeegee. This allows two different pastes to be printed on the object to be printed in the same area.

According to a preferred embodiment of the utility model, the isolation barrier squeegee is bonded to the main squeegee against the pushing side of the main squeegee.

According to a preferred embodiment of the utility model, the end of the isolation barrier squeegee opposite to the end fixed to the main squeegee is pointed. This allows the isolation barrier squeegee to better separate different slurries.

Drawings

The utility model is described in detail below by way of exemplary embodiments with reference to the accompanying drawings, in which:

fig. 1 is a front view of a squeegee for paste printing according to an embodiment of the present invention;

FIG. 2 is a top view of the squeegee shown in FIG. 1;

FIG. 3 is a left side view of the squeegee shown in FIG. 1;

fig. 4 is a view of the view of fig. 3 rotated at an angle.

The figures are purely diagrammatic and not drawn to scale. They show only those parts which are necessary for clarifying the present invention, and other parts may be omitted or simply mentioned. The utility model may also comprise other components than those shown in the figures.

Detailed Description

A squeegee for paste printing according to an embodiment of the present invention is described below with reference to the drawings. In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention to those skilled in the art. It will be apparent, however, to one skilled in the art that the present invention may be practiced without some of these specific details. Furthermore, it should be understood that the utility model is not limited to the specific embodiments described. Rather, it is contemplated that the utility model may be practiced with any combination of the following features and elements, whether or not they relate to different embodiments. Thus, the following features, embodiments and advantages are merely illustrative and should not be considered elements or limitations of the claims except where explicitly recited in a claim.

The doctor blade of a preferred embodiment of the utility model is described in detail below with reference to a specific embodiment of printing conductive silver lines on a silicon wafer used to prepare a solar cell sheet. It is clear, however, that the spreading of the utility model can also be used in any situation where it is desired to carry out comparative tests on at least two different slurries.

Fig. 1 to 3 show a squeegee 1 according to a preferred embodiment of the present invention in front, top and left side views. Fig. 4 is a view shown in fig. 3 rotated at an angle such that the printing direction F of the printing press is in a horizontal direction, in order to make it easier to understand the operation of the squeegee 1.

As shown in fig. 1 to 4, a squeegee 1 according to an embodiment of the present invention includes a connection member 10, a main squeegee 20 fixed to the connection member 10, and a barrier dam squeegee 30 fixed to the main squeegee 20. The main squeegee 20 includes a pushing side 21 for pushing the paste forward and can be connected to a printer via a connecting member 10, so that the paste is pushed by the pushing side 21 under the drive of the printer to print the paste onto a silicon wafer (i.e., an object to be printed) via a printing screen. In the printed state, the isolation barrier squeegee 30 extends in the print direction F (shown in fig. 4) to allow different pastes to be printed onto the silicon wafer in an isolated manner from each other.

As shown in fig. 1, the connecting member 10 includes a connecting hole 11, and the connecting member 10 can be fixed to a printing machine via a jig which is clamped to the connecting member 10 through the connecting hole 11. It will be appreciated that the connector 10 may be secured to the printer by any suitable method.

As shown in fig. 1 to 3, the main squeegee 20 has a rectangular parallelepiped shape. The main squeegee 20 has a width W1 (shown in fig. 2) and a height H1 (shown in fig. 4). In a preferred embodiment, the width W1 is substantially equal to the width of a silicon wafer, e.g., about 180mm, and the height H1 is about 13 mm. However, it should be understood that main squeegee 20 may have any suitable width W1 and height H1.

The push side 21 comprises a first edge forming a printing edge 22 for abutting against a printing screen and comprises a second edge 23 opposite the first edge. During printing, the main squeegee 20 pushes the paste from one end of the printing screen to the other end of the printing screen by pushing the side surface 21 under the driving of the printing machine, and the printing edge 22 abuts against the printing screen and applies a certain pressure on the printing screen, so that the paste is printed on the silicon wafer through the mesh of the printing screen. Obviously, it should be understood that the main squeegee 20 may have any suitable shape as long as it has suitable pushing sides and printing edges.

As shown in fig. 3, the isolation barrier squeegee 30 is bonded to the main squeegee 20 against the pushing side 21 of the main squeegee 20. The connecting piece 10 is bonded to the main frictioning 20 against the side of the main frictioning 20 opposite to the pushing side 21. It should be understood that connector 10 may be bonded to other sides of main squeegee 20 and may be secured to main squeegee 20 in other suitable manners, such as a threaded connection. Similarly, isolation barrier squeegee 30 may also be secured to main squeegee 20 in other suitable manners, such as a threaded connection.

As shown in fig. 4, the isolation barrier squeegee 30 includes a first face 31 extending from the push side 21 adjacent the printing edge 22 of the main squeegee 20, the first face 31 being offset a distance D with respect to the printing edge 22 of the main squeegee 20 toward the second edge 23 of the push side 21 of the main squeegee 20. During printing, the printing edge 22 bears against the printing screen and exerts a certain pressure on the printing screen, thereby deforming the printing screen, which allows the first face 31 of the isolating barrier squeegee 30 to bear against the printing screen. By setting the distance D, the isolation blocking squeegee 30 is not easy to damage the printing screen. Preferably, the distance D is not greater than 1mm so that different slurries can be effectively separated by the isolation barrier squeegee 30.

To further avoid damage to the printing screen, the hardness of the isolation barrier squeegee 30 is selected to be less than the hardness of the main squeegee 20. Preferably, isolation barrier skim 30 has a shore hardness of 55-75 degrees and main skim 20 has a shore hardness of 70-80 degrees. More preferably, isolation barrier skim 30 has a shore hardness of 65 degrees and main skim 20 has a shore hardness of 80 degrees.

As shown in fig. 3 and 4, the second face 32 of the separation blocking squeegee 30 fixed to the main squeegee 20 forms an angle α with the first face 31 of the separation blocking squeegee 30, which corresponds to the angle of the pushing side face 21 of the main squeegee 20 with respect to the printing direction F. Thus, the first side 31 of the barrier squeegee 30 can be brought into abutment with the printing screen during printing. Typically, the included angle is 50 ° to 70 °. Preferably, the included angle is 55 °.

As shown in fig. 1 and 2, the squeegee 1 includes a barrier dam squeegee 30, and the barrier dam squeegee 30 is fixed to the main squeegee 20 at a middle position in the width direction of the main squeegee 20 so that two different pastes can be printed on a silicon wafer in the same area. Obviously, it should be understood that the squeegee 1 may include more than one barrier isolation squeegee 30 for printing more various pastes, and the position of the barrier isolation squeegee 30 may or may not be provided at the intermediate position of the main squeegee 20 as needed.

As shown in fig. 1 to 4, the barrier dam squeegee 30 is a prism table having a trapezoidal section in the printing direction F. As shown in fig. 2 and 4, the barrier dam 30 has a width W2, a bottom length L2, and a height H2. If the width W2 is too wide, the barrier squeegee 30 will take up too much print area when printing; if the width W2 is too narrow, the separation blocking squeegee 30 may be deformed during printing. If the bottom length L2 is too short, an effective isolation barrier effect is not achieved; if the bottom length L2 is too long, the spacer squeegee 30 tends to wobble or break the printing screen during printing. In a preferred embodiment, the width W2 of barrier dam 30 is 5mm to 8mm and the bottom length L2 is 37 mm. It should be understood that one skilled in the art may select an appropriate width W2 and bottom length L2 for barrier dam 30 based on the hardness of barrier dam 30, the viscosity of the slurry, etc. In addition, as shown in fig. 3 and 4, the height H2 of the barrier dam bar 30 is greater than the height H1 of the main bar 20. In a preferred embodiment, height H1 is 13mm and height H2 is 15.5 mm. However, it should be understood that height H2 of barrier dam 30 may be equal to or even less than height H1 of main dam 20.

As shown in fig. 1 to 3, the free end of the isolation barrier squeegee 30 opposite to the end fixed to the main squeegee 20 is pointed to better separate the different slurries. The tip is in the shape of an isosceles triangle as viewed from the top of the barrier dam 30. However, it should be understood that the free end portion may also be of any suitable shape, such as rounded or even flat.

Although the present invention has been described with reference to the preferred embodiments, it is not limited thereto. Various changes and modifications within the spirit and scope of the present invention may be made by those skilled in the art without departing from the spirit and scope of the present invention, and therefore the scope of the present invention should be determined by that defined in the appended claims.

Claims

1. A squeegee (1) for printing of paste, characterized in that the squeegee (1) comprises a connection member (10), a main squeegee (20) fixed to the connection member (10) and at least one barrier squeegee (30) fixed to the main squeegee (20), the main squeegee (20) comprising a push side (21) for pushing paste forward and being connected to a printing machine via the connection member (10), the at least one barrier squeegee (30) being fixed to the push side (21) of the main squeegee (20) and extending in a printing direction (F) to allow at least two different pastes to be printed onto an object to be printed in a manner isolated from each other.

2. A squeegee (1) for paste printing according to claim 1, wherein the push side (21) comprises a first edge and a second edge (23) opposite the first edge, the first edge forming a printing edge (22) for abutting against a printing screen, the at least one isolation barrier squeegee (30) comprising a first face (31) extending from the push side (21) adjacent to the printing edge (22), the first face (31) being offset with respect to the printing edge (22) by a distance (D) towards the second edge (23).

3. Doctor blade (1) for paste printing according to claim 2, characterised in that said distance (D) is not greater than 1 mm.

4. Squeegee (1) for paste printing according to claim 2 or 3, wherein a second face (32) of the isolation barrier squeegee (30) fixed to the main squeegee (20) forms an angle (α) with the first face (31) of the isolation barrier squeegee (30), which angle (α) corresponds to the angle of the pushing side (21) of the main squeegee (20) with respect to the printing direction (F).

5. Doctor blade (1) for paste printing according to claim 4, characterised in that the angle (α) is 55 °.

6. A squeegee (1) for paste printing according to any one of claims 1-3, wherein the hardness of the barrier squeegee (30) is less than the hardness of the main squeegee (20).

7. Doctor blade (1) for paste printing according to claim 6, characterised in that the barrier dam doctor blade (30) has a shore hardness of 55-75 degrees and/or the main doctor blade (20) has a shore hardness of 70-80 degrees.

8. A squeegee (1) for paste printing according to any one of claims 1-3, wherein the squeegee (1) comprises one of the separation barrier squeegees (30), the separation barrier squeegee (30) being fixed to the main squeegee (20) at an intermediate position in the width direction of the main squeegee (20).

9. A squeegee (1) for paste printing according to any one of claims 1-3, wherein the isolation barrier squeegee (30) is bonded to the main squeegee (20) against the push side (21) of the main squeegee (20).

10. A squeegee (1) for paste printing according to any one of claims 1-3, wherein the end of the isolation barrier squeegee (30) opposite to the end fixed to the main squeegee (20) is pointed.