Photovoltaic cell interconnection pressing tool and stringer machine

Abstract

A photovoltaic cell interconnection pressing tool and a stringer machine. The photovoltaic cell interconnection pressing tool comprises a pressing plate (310) and a plurality of groups of positioning pressing needles (320). Each group of positioning pressing needles (320) is used for pressing a solder ribbon (60). The pressing plate (310) is made of a light-transmitting material. The lower surface of the pressing plate (310) is provided with a plurality of mounting areas (330) for mounting the positioning pressing needles (320). Each group of positioning pressing needles (320) is mounted within a corresponding mounting area (330). The thermal conductivity of the positioning pressing needles (320) is higher than the thermal conductivity of the pressing plate (310). The present solution can improve the uniformity of the heating temperature on battery cells, enhance the dimensional stability of the pressing tool, reduce the energy consumption of soldering, and improve the alignment of solder ribbons during soldering.

Description

Photovoltaic cell interconnection press and string welding machine Technical Field

[0001] The present invention mainly relates to the technical field of photovoltaic cell processing equipment, and in particular to a photovoltaic cell interconnection press and a string welding machine. Background Art

[0002] Traditional photovoltaic cells are usually connected by welding. Specifically, the cells are welded using an automatic stringing machine. During the welding process, the soldering ribbon contacts the electrode area of ​​the battery after a positioning step. A press is used to tightly fit the soldering ribbon to the electrode surface. It then enters a heating light box and, under the action of an external heat source, is welded to the battery electrode. Among them, the heating source widely uses a group of cylindrical radiation sources with uniform infrared radiation brightness in all directions. This type of radiation source is a linear radiation source with a relatively small ratio of cylinder diameter to length. It is also called an infrared lamp tube and is placed at equal intervals on a plane parallel to the photovoltaic cell. During the welding heating process, the radiation source radiates heat to the battery, providing heat to melt the coating on the surface of the soldering ribbon, so that the coating is welded to the battery electrode.

[0003] When using traditional presses, a large proportion of reflected energy, about 65%, will be reflected back to the light source above the press, resulting in energy waste and heat accumulation in the lamp tube itself. In addition, the irregular reflection of infrared rays in the light box makes temperature uniformity control more difficult; about 20% of the heat is absorbed by the press, causing the temperature of the press itself to rise, and the thermal expansion drives the positioning pressure pins fixed on the press for holding the solder strip to move, resulting in a decrease in the ability to position the solder strip; only about 10% of the heat passes through the press in the non-hollow area, resulting in a huge difference in infrared direct radiation energy density between the non-hollow area and the hollow area of ​​the press, resulting in a significant temperature difference in the battery surface area in contact with the press. After measurement, there is a temperature difference of about 50°C between the direct radiation area and the non-direct radiation area. This temperature difference will make it impossible to accurately control the welding quality.

[0004] The main shortcomings of traditional presses are: first, the press will block or absorb part of the infrared heat source, resulting in uneven heating temperature of the battery (cell); second, the press blocks the infrared heat source. Under the same heating effect, the output power of the infrared heat source needs to be increased, which increases the overall energy consumption of the heat source; third, the press itself absorbs a large proportion of infrared radiation, causing it to deform due to heat, which is not conducive to the press aligning with the solder strip.

[0005] Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a photovoltaic cell interconnection press and a string welding machine to improve the uniformity of the heating temperature of the cell and the stability of the press size, reduce welding energy consumption, and enhance the alignment effect of the welding ribbon during the welding process.

[0007] In order to solve the above technical problems, in the first aspect, the present invention provides a photovoltaic cell interconnection press, comprising: a pressing plate and several groups of positioning pressure pins, each group of the positioning pressure pins is used to press a welding strip, wherein the pressing plate is a pressing plate made of a light-transmitting material, and the lower surface of the pressing plate has several installation areas for installing the positioning pressure pins; each group of the positioning pressure pins is installed in the corresponding installation area, and the thermal conductivity of the positioning pressure pins is higher than the thermal conductivity of the pressing plate.

[0008] Optionally, the installation area is an installation groove, and each group of the positioning pressure pins is installed in the corresponding installation groove.

[0009] Optionally, the installation area is a plurality of installation holes, and each positioning pressure pin in each group of the positioning pressure pins is installed in a corresponding installation hole.

[0010] Optionally, the positioning pressure needle is a positioning pressure needle with upward and downward movable buffering performance.

[0011] Optionally, the side edges of the pressing plate are chamfered side edges.

[0012] Optionally, the thermal conductivity of the positioning pressure pin is greater than 100 W / m·K.

[0013] Optionally, the number N of positioning pins corresponding to each solder strip and the length L of the pressure plate along the solder strip have the following relationship: L / 30≤N≤L / 3, wherein L and the values ​​30 and 3 are in millimeters.

[0014] Optionally, the shape of the bottom surface of the positioning pressure pin in contact with the welding strip includes one of the following shapes: circular, rectangular, elliptical or polygonal, and the maximum width of the bottom surface of the positioning pressure pin is greater than 1 mm.

[0015] Optionally, the area of ​​the pressing plate outside the installation area has a hollow area, and the hollow area includes a first hollow area located at both ends of the pressing plate and / or a second hollow area adjacent to the positioning pressure pin.

[0016] Optionally, the material of the pressing plate includes one of the following materials: quartz, glass or transparent high-temperature resistant resin polymer.

[0017] Optionally, the material of the positioning pressure pin includes one of the following non-transparent materials: metal, ceramic thermal conductive material or metal-based composite material.

[0018] Optionally, the material of the positioning pressure pin includes one of the following materials: aluminum alloy, stainless steel, silicon carbide ceramics, beryllium oxide ceramics, silicon nitride ceramics, aluminum-based composite materials or copper-based composite materials.

[0019] Optionally, the upper surface and / or lower surface of the pressing plate has an anti-reflection film.

[0020] Optionally, the upper surface and / or lower surface of the pressing plate in the non-light-transmitting area has a reflective film.

[0021] In a second aspect, the present invention further provides a string welding machine, comprising an infrared heating lamp tube, a conveyor belt, a cooling fan and a machine body, and also comprising the photovoltaic cell interconnection press as described in the first aspect.

[0022] Compared with the prior art, the present invention has the following advantages: a pressure plate is provided which is made of a light-transmitting material, and the lower surface of the pressure plate has several installation areas for installing positioning pressure pins. In addition, each group of positioning pressure pins is installed in the corresponding installation area, and the thermal conductivity of the positioning pressure pins is higher than that of the pressure plate, thereby improving the uniformity of the heating temperature of the battery cell and the stability of the size of the press, improving the ability of the press to position the welding strip, enhancing the welding strip alignment effect during welding, and reducing welding energy consumption.

[0023] Summary of the Figures

[0024] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which:

[0025] FIG1 is a schematic structural diagram of a conventional photovoltaic cell interconnection press;

[0026] FIG2 is a schematic diagram of the spectral transmission, absorption and reflection characteristics of the non-hollowed area of ​​a conventional photovoltaic cell interconnection press;

[0027] FIG3 is a schematic structural diagram of a photovoltaic cell interconnection press according to an embodiment of the present invention;

[0028] FIG4 is a schematic structural diagram of a positioning press pin in a photovoltaic cell interconnection press of the present invention;

[0029] FIG5 is a schematic diagram of another structure of a photovoltaic cell interconnection press in one embodiment of the present invention;

[0030] FIG6 is a schematic diagram of another structure of a photovoltaic cell interconnection press in one embodiment of the present invention;

[0031] FIG7 is a schematic diagram of the spectral transmission, absorption and reflection characteristics of a typical photovoltaic cell interconnection press using the structure shown in FIG5;

[0032] FIG8 is a schematic diagram of the structure of the anti-reflection film in the photovoltaic cell interconnection press of the present invention;

[0033] FIG9 is a schematic diagram of the structure of the reflective film in the photovoltaic cell interconnection press of the present invention;

[0034] FIG10 is a schematic diagram of an application of a photovoltaic cell interconnection press in accordance with an embodiment of the present invention;

[0035] FIG11 is a second schematic diagram of the application of the photovoltaic cell interconnection press in one embodiment of the present invention.

[0036] Figure numerals: 10 - infrared heating lamp; 20 - machine body; 30 - press; 310 - pressure plate, 320 - positioning pressure pin, 330 - installation area, 340 - hollow area (including the first hollow area 3401 and the second hollow area 3402), 350 - anti-reflection film, 360 - reflective film; 40 - cooling fan; 50 - transmission belt; 60 - welding belt.

[0037] Preferred embodiments of the present invention

[0038] The present invention is further described below in conjunction with specific implementation methods and accompanying drawings. More details are set forth in the following description to facilitate a full understanding of the present invention. However, the present invention can obviously be implemented in a variety of other ways different from the description. Those skilled in the art can make similar generalizations and deductions based on actual application situations without violating the connotation of the present invention. Therefore, the scope of protection of the present invention should not be limited by the content of this specific implementation method.

[0039] For example, a description later in the specification of a first feature being formed above or on a second feature may include an embodiment in which the first and second features are directly connected, or an embodiment in which an additional feature is formed between the first and second features, thereby eliminating the need for a direct connection between the first and second features. Furthermore, when a first element is described as being connected to or coupled to a second element, the description includes embodiments in which the first and second elements are directly connected or coupled to each other, as well as embodiments in which the first and second elements are indirectly connected or coupled to each other using one or more other intervening elements.

[0040] Although the present invention is disclosed above with reference to preferred embodiments, this is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modifications, equivalent variations, and modifications made to the above embodiments in accordance with the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection defined by the claims of the present invention.

[0041] Figure 1 is a schematic diagram of the structure of a traditional photovoltaic cell interconnection press. As shown in Figure 1, during the welding process between the photovoltaic cell electrode and the welding ribbon, stainless steel or aluminum alloy is usually used as the press material. A near-infrared light source is used as the heat source of the string welding machine, and the photovoltaic cell is directly heated through the hollow area of ​​the press. Generally, the hollow area of ​​the press accounts for about 60%-70%. In order to maintain sufficient structural strength of the press and ensure that the positioning pressure pins on the press have enough space to be installed on the press, the 30%-40% non-hollow area is difficult to eliminate.

[0042] Figure 2 is a schematic diagram of the spectral transmittance, absorption and reflection characteristics of the non-hollow area of ​​a traditional photovoltaic cell interconnection press. As shown in Figure 2, when using a traditional press, most of the heating energy of the heat source on the photovoltaic cell is the energy directly radiated to the cell by electromagnetic waves in the infrared band, and the transmittance of the press in the infrared band (wavelength above 780nm) is low, with an average value of only about 10%. Most of the infrared electromagnetic waves are reflected from the metal surface and leave the press, and about 20% of the infrared electromagnetic waves are absorbed by the press, heating the press itself.

[0043] To improve the performance of the press 30 and enhance the welding effect of the soldering ribbon 60, this embodiment provides a photovoltaic cell interconnection press. Figure 3 is a schematic structural diagram of a photovoltaic cell interconnection press in one embodiment of the present invention. Referring to Figure 3, the structure of the press 30 shown mainly includes: a pressing plate 310 and several groups of positioning pins 320. Each group of positioning pins 320 is used to press and hold a soldering ribbon 60. The pressing plate 310 is made of a light-transmitting material. The lower surface of the pressing plate 310 has several mounting areas 330 for mounting the positioning pins 320. Each group of positioning pins 320 is mounted in a corresponding mounting area 330. The thermal conductivity of the positioning pins 320 is higher than that of the pressing plate 310.

[0044] Referring to Figure 3, five groups of positioning pins 320 are shown, namely T1, T2, T3, T4 and T5, that is, the press 30 shown in the figure can simultaneously hold and weld five solder strips 60. In this embodiment, the pressing plate 310 is made of a light-transmitting material, so that the infrared light source can transfer heat to the battery cell through the press 30 to the greatest extent, ensuring that the infrared heat source can directly act on the non-pressing pin area of ​​the battery cell, thereby improving the utilization rate of welding heat. In addition, the press 30 has light-transmitting properties, and extremely low heat is absorbed by the press 30. The temperature of the press 30 itself rises very little, avoiding thermal expansion, and the thermal expansion coefficient of the press 30 itself is 1 to 2 orders of magnitude lower than that of metal, which effectively suppresses the displacement of the positioning pins 320 under the irradiation of the light source, greatly improving the ability of the press 30 to position the solder strips 60. Furthermore, the thermal conductivity of the positioning pressure pin 320 is higher than that of the pressure plate 310, and it is made of an opaque material. Its main functions are as follows: 1) During the heating process, the transparent pressure plate 310 causes the non-pressure pin area of ​​the battery cell to heat up rapidly, and the heated battery cell conducts the heat to the battery cell area in the area shielded by the positioning pressure pin 320, and the heat continues to conduct to the soldering ribbon 60, causing the solder on the soldering ribbon 60 to melt. At the same time, under the premise of ensuring the melting of the solder, due to the shielding of the positioning pressure pin 320, the temperature of this area is lower than the temperature of the non-pressure pin area that is directly transmitted; 2) After the battery cell is heated, when it flows to the non-heating area, through the contact between the high thermal conductivity positioning pressure pin 320 and the soldering ribbon 60, the positioning pressure pin 320 with a lower temperature can quickly dissipate heat to the outside and absorb the heat of the soldering ribbon 60 in contact with it, so as to achieve the cooling effect of the welding point between the soldering ribbon 60 and the battery electrode in a very short time, and ensure that the battery cell quickly forms a solid weld before the press 30 is removed. In short, the use of the positioning pressure pin 320 made of opaque material and high thermal conductivity can accelerate the cooling and solidification of the solder, the press 30 can be quickly recovered, the battery cell welding time is shortened, and the production efficiency is significantly improved.

[0045] It should be noted that, in actual use, the pressing tool 30 generally has the pressing plate 310 located above and the positioning pressure pin 320 located below. In the figure, the positioning pressure pin 320 is located above the pressing plate 310 in order to more clearly show the structure of the pressing tool 30 of this embodiment, and does not represent the actual use of the pressing tool 30.

[0046] In one example, the material of the pressure plate 310 includes one of the following materials: quartz, glass, or a transparent, high-temperature-resistant resin polymer. Using quartz, glass, or a transparent, high-temperature-resistant resin polymer for the pressure plate 310 allows the infrared light source to transfer heat to the cell to a greater extent, ensuring that the infrared heat source can directly act on the non-pressing pin area of ​​the cell, thereby improving the utilization rate of the welding heat.

[0047] In one example, the installation area 330 is an installation groove, and each set of positioning pressure pins 320 is installed in a corresponding installation groove.

[0048] In one example, the mounting area 330 is a plurality of mounting holes, and each positioning pressure pin 320 in each group of positioning pressure pins is installed in a corresponding mounting hole.

[0049] When the installation area 330 is in the installation slot mode, each group of positioning pins 320, such as the first group T1 in Figure 3, can be directly installed in the installation slot as a whole, which is convenient and quick. When the installation area 330 is a mounting hole, each positioning pin 320 is installed separately. Compared with the installation slot mode, the installation hole mode requires more installation operations for the positioning pins 320, but the advantages of the installation hole mode are that, first, the area of ​​the slots or holes in the installation area 330 on the pressure plate 310 can be reduced, reducing the risk of the press 30 breaking. Second, each positioning pin 320 is independent of each other, and the number of positioning pins 320 in each group can be changed as needed to meet the actual pressing requirements of the welding strip 60. For example, still taking the positioning pins 320 of the T1 group in Figure 3 as an example, there are currently 10 positioning pins 320 in the T1 group. If the welding of a welding strip 60 of a certain battery cell only requires 5 positioning pins 320, the remaining 5 positioning pins 320 can be directly removed. Therefore, the adaptability of the installation hole mode is better.

[0050] In one example, the positioning pin 320 is a positioning pin with a movable buffering function. Figure 4 is a schematic diagram of the structure of the positioning pin in the photovoltaic cell interconnection press of the present invention. Referring to Figure 4, the main structure of the positioning pin 320 includes an elastic component (such as a spring). When the positioning pin 320 presses the solder ribbon 60, the positioning pin 320 can provide a buffering effect on the solder ribbon 60 to avoid damage to the solar cell.

[0051] In one example, the side edges of the pressing plate 310 are chamfered. In order to prevent the pressing tool 30 (specifically, the pressing plate 310) from causing edge damage due to collision, the pressing plate 310 of the pressing tool 30 can be chamfered to improve its durability. As shown in Figure 5, E in the figure represents the side edge of the pressing plate 310, and A represents the top corner of the pressing plate 310. It can be seen that the chamfering treatment of the pressing plate 310 can be performed on both the side edge of the pressing plate 310 and the top corner of the pressing plate 310. The chamfered design of the outer edge of the pressing plate 310 improves the overall strength and ability to resist external stress of the pressing tool 30, and also increases the life of the pressing tool 30. In addition, in order to prevent the pressing tool 30 from causing edge damage due to collision, the pressing plate 310 can also be treated or improved in other ways. For example, a circle of high-temperature tape (such as Teflon) can be affixed around the side edge of the pressing plate 310, which can also prevent edge damage of the pressing tool 30 to a certain extent.

[0052] In one example, the thermal conductivity of the positioning pressure pin 320 is greater than 100 W / m·K. Furthermore, the material of the positioning pressure pin 320 can include one of the following non-transparent materials: metal, ceramic thermal conductive material, or metal-based composite material. More preferably, the material of the positioning pressure pin 320 can include one of the following materials: aluminum alloy, stainless steel, silicon carbide ceramic, beryllium oxide ceramic, silicon nitride ceramic, aluminum-based composite material, or copper-based composite material.

[0053] In one example, the number N of positioning pins 320 corresponding to each solder strip 60 and the length L of the pressing plate 310 along the solder strip 60 have the following relationship: L / 30≤N≤L / 3, wherein the units of L, the values ​​30, and the value 3 are millimeters (mm), and the above formula can be expressed in detail as Lmm / 30mm≤N≤Lmm / 3mm. Of course, if other units are used, the expression of the above formula will change slightly, but the actual content remains unchanged. For example, if the unit is centimeter (cm), the above formula can be expressed as Lcm / 3cm≤N≤Lcm / 0.3cm. For other units, no further details will be given here. From this relationship, it can be seen that when the length of the pressing plate 310 is constant, the number of positioning pins 320 that hold each solder strip 60 needs to be controlled within a reasonable range. Too few positioning pins 320 cannot effectively hold the solder strip 60. On the other hand, too many positioning pins 320 will cause the structure of the pressing tool 30 to be redundant, wasting materials.

[0054] In one example, the shape of the bottom surface of the positioning pressure pin 320 in contact with the welding strip 60 includes one of the following shapes: circular, rectangular, elliptical or polygonal, and the scale of the maximum width of the bottom surface of the positioning pressure pin 320 is greater than 1 mm. In addition, the bottom surface of the positioning pressure pin 320 can also have a groove or the positioning pressure pin 320 can adopt other shapes, as long as the positioning pressure pin 320 can press the welding strip 60, there is no specific limitation here. It can be understood that although the shape of the bottom surface of the positioning pressure pin 320 can be various forms, the positioning pressure pin 320 with a circular bottom surface is generally used. The advantage is that the positioning pressure pin 320 with a circular bottom surface is easier to prepare (such as making the positioning pressure pin 320 as a whole into a cylindrical shape), and it is also more convenient during installation. In order to ensure the rigid pressing effect of the positioning pressure pin 320, the scale of the maximum width of the bottom surface of the positioning pressure pin 320 is greater than 1 mm, that is, the positioning pressure pin 320 can at least produce a pressing effect on the welding strip 60 that is greater than 1 mm in length. The positioning pressure pin 320 is located within 10 mm of the electrode area to ensure that the welding ribbon 60 is well welded to the battery electrode during the welding process. The position of the positioning pressure pin 320 and the electrode can be positive pressure, tangent or non-intersecting, and the specific position correspondence is determined according to actual conditions.

[0055] In one example, the area outside the installation area 330 on the pressing plate 310 has a hollow area 340 (different from the traditional pressing tool that uses the hollow area to achieve light transmission), and the hollow area includes a first hollow area 3401 located at both ends of the pressing plate 310 and / or a second hollow area 3402 adjacent to the positioning pressure pin 320. In this embodiment, the hollow area of ​​the pressing tool 30 accounts for <50%, and the non-hollow area can maintain the sufficient structural strength of the pressing tool 30, ensuring that the positioning pressure pin 320 on the pressing tool 30 has enough space to be positioned on the pressing tool 30. The hollow area 340 set in this embodiment, wherein the main function of the first hollow area 3401 is to facilitate the installation and positioning of the pressing tool 30, and the main function of the second hollow area 3402 is that the hollow area can effectively volatilize and discharge the flux on the surface of the welding ribbon 60 during the heating and welding process, thereby preventing corrosion of the surface of the pressing tool 30 and preventing corrosion and aging of the battery surface due to excessive flux concentration during the aging process after packaging.

[0056] In one example, the upper surface and / or lower surface of the pressing plate 310 has an anti-reflection film 350. In order to improve the light transmittance level of the pressing tool 30, the pressing tool 30 can be subjected to single-sided or double-sided coating treatment. Refer to Figures 5 and 7. During the welding process, most of the heating energy of the heat source to the photovoltaic cell is the energy directly radiated to the cell by electromagnetic waves in the infrared band. The high infrared transmittance of the pressing tool 30 in the infrared band (wavelength above 780nm) can reach an average transmittance of about 93%. Less than 1% of the infrared electromagnetic waves are absorbed by the pressing tool 30, and the extremely low heat is absorbed by the pressing tool 30, so that the temperature of the pressing tool 30 itself rises very little.

[0057] In this embodiment, an anti-reflection film 350 can be provided on the pressing plate 310, so that the pressing tool 30 can overcome many adverse effects. This is mainly manifested in that the pressing tool 30 in this embodiment reflects only about 6% of the energy in the infrared band, and the energy utilization rate of the light source is significantly high, which will not cause heat accumulation in the lamp tube itself.

[0058] In one example, the upper and / or lower surfaces of the pressing plate 310 in areas not requiring light transmission are provided with a reflective film 360. For example, for areas of the insulating adhesive of an IBC (interdigitated back contact) battery that do not require welding, such as the 5%-15% of the insulating adhesive surface outside the electrodes, reflective film 360 can be added to the corresponding locations on the pressing plate 310 to reduce the heat applied to the insulating adhesive and prevent it from turning yellow due to heat. Anti-reflective film 350 can also be added to other locations that require heat to ensure the necessary welding heat.

[0059] Referring to Figure 8 , an anti-reflection film 350 can be applied to the upper surface of the pressing plate 310, and a reflective film 360 can be applied to a portion of the lower surface of the pressing plate 310 where light transmission is not required. Referring to Figure 9 , a reflective film 360 can also be applied to the upper surface of the pressing plate 310. It can be seen that whether the anti-reflection film 350 and the reflective film 360 are provided, whether they are provided simultaneously, and where they are provided on the pressing plate 310 can be reasonably arranged based on actual needs and will not be listed here.

[0060] An embodiment of the present invention provides a string welding machine, the structure of which includes the aforementioned photovoltaic cell interconnection press. Of course, the string welding machine also includes an infrared heating lamp 10, a conveyor belt 50, a cooling fan 40 and a body 20, etc. To avoid repetition, they are not described here.

[0061] Figure 10 is an application schematic diagram of a photovoltaic cell interconnection press in an embodiment of the present invention. Referring to Figure 10, the highly light-transmitting press 30 can reduce the amount of heat it receives, thereby reducing its thermal stress expansion problem, improving the dimensional stability of the press 30, and enhancing the alignment effect of the soldering ribbon 60 during the welding process.

[0062] FIG11 is a second schematic diagram of the application of a photovoltaic cell interconnection press in one embodiment of the present invention. Referring to FIG11 , the press 30 is provided with a coating. The coating on the press 30 can be single-sided or double-sided. The coating can be an anti-reflection film 350, the main function of which is to improve the light transmittance of the press 30. During welding, the infrared heat source light can pass through the press 30 and directly act on the cell and the soldering ribbon 60, which can greatly reduce the amount of infrared light reflected by the press 30. The better light transmittance reduces the heat required for string welding, thereby reducing welding energy consumption. In addition, the coating on the surface of the press 30 can improve the corrosion resistance of the press 30.

[0063] The photovoltaic cell interconnection press or string welding machine provided in this embodiment has a press plate 310 made of a light-transmitting material, and the lower surface of the press plate 310 has several installation areas for installing positioning pressure pins 320. In addition, each group of positioning pressure pins 320 is installed in the corresponding installation area, and the thermal conductivity of the positioning pressure pins 320 is higher than the thermal conductivity of the press plate, thereby improving the uniformity of the heating temperature of the battery cell and the stability of the size of the press 30, improving the ability of the press 30 to position the welding strip 60, enhancing the welding strip alignment effect during welding, and reducing welding energy consumption.

[0064] The basic concepts have been described above. It will be apparent to those skilled in the art that the above disclosures are merely illustrative and do not constitute limitations on this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and amendments to this application. Such modifications, improvements, and amendments are suggested in this application and remain within the spirit and scope of the exemplary embodiments of this application.

Claims

1. A photovoltaic cell interconnection press, characterized in that: include: A pressing plate and a plurality of groups of positioning pressing pins, each group of the positioning pressing pins is used to press and hold a welding strip, wherein: The pressing plate is a pressing plate made of a light-transmitting material, and the lower surface of the pressing plate has a plurality of installation areas for installing the positioning pressing pins; Each group of the positioning pressure pins is installed in a corresponding installation area, and the thermal conductivity of the positioning pressure pins is higher than the thermal conductivity of the pressure plate.

2. The photovoltaic cell interconnection press as claimed in claim 1, characterized in that: The installation area is an installation groove, and each group of positioning pressure pins is installed in the corresponding installation groove.

3. The photovoltaic cell interconnection press as claimed in claim 1, characterized in that: The installation area is a plurality of installation holes, and each positioning pressure pin in each group of positioning pressure pins is installed in a corresponding installation hole.

4. The photovoltaic cell interconnection press as claimed in claim 1, characterized in that: The positioning pressing needle is a positioning pressing needle with upward and downward movable buffering performance.

5. The photovoltaic cell interconnection press as claimed in claim 1, characterized in that: The side edges of the pressing plate are chamfered side edges.

6. The photovoltaic cell interconnection press as claimed in claim 1, characterized in that: The thermal conductivity of the positioning pressure pin is greater than 100 W / m·K.

7. The photovoltaic cell interconnection press as claimed in claim 1, characterized in that: The number N of positioning pressure pins corresponding to each of the solder strips and the length L of the pressure plate along the solder strip have the following relationship: L / 30≤N≤L / 3, wherein L and the values ​​30 and 3 are in units of millimeters.

8. The photovoltaic cell interconnection press as claimed in claim 1, characterized in that: The shape of the bottom surface of the positioning pressure pin in contact with the welding strip includes one of the following shapes: circular, rectangular, elliptical or polygonal, and the maximum width of the bottom surface of the positioning pressure pin is greater than 1 mm.

9. The photovoltaic cell interconnection press as claimed in claim 1, characterized in that: The area of ​​the pressing plate outside the installation area has a hollow area, and the hollow area includes a first hollow area located at both ends of the pressing plate and / or a second hollow area adjacent to the positioning pressure needle.

10. The photovoltaic cell interconnection press as claimed in claim 1, characterized in that: The material of the pressing plate includes one of the following materials: quartz, glass or transparent high temperature resistant resin polymer.

11. The photovoltaic cell interconnection press as claimed in claim 1, characterized in that: The material of the positioning pressure pin includes one of the following non-transparent materials: metal, ceramic thermal conductive material or metal-based composite material.

12. The photovoltaic cell interconnection press as claimed in claim 11, characterized in that: The material of the positioning pressure needle includes one of the following materials: aluminum alloy, stainless steel, silicon carbide ceramics, beryllium oxide ceramics, silicon nitride ceramics, aluminum-based composite materials or copper-based composite materials.

13. The photovoltaic cell interconnection press as claimed in claim 1, characterized in that: The upper surface and / or the lower surface of the pressing plate has an anti-reflection film.

14. The photovoltaic cell interconnection press as claimed in claim 1, characterized in that: The pressing plate does not need to have a reflective film on the upper surface and / or the lower surface of the light-transmitting region.

15. A string welding machine, comprising an infrared heating lamp tube, a conveyor belt, a cooling fan and a machine body, characterized in that: It also includes the photovoltaic cell interconnection press as described in any one of claims 1 to 14.

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