Electric contact structure suitable for back contact battery and laser-induced sintering system

Abstract

The utility model discloses an electric contact structure suitable for a back contact battery and a laser-induced sintering system, which belong to the technical field of solar battery manufacturing, and are characterized in that N-region metal plates are arranged corresponding to N-region grid lines on a battery piece, P-region metal plates are arranged aiming at P-region grid lines, and metal bulges arranged corresponding to two grid lines on the two metal plates are utilized to form an electric contact structure suitable for a back contact battery. Therefore, after the two metal plates abut against and are matched with the battery piece respectively, all the N-region grid lines and all the P-region grid lines on the battery piece are conducted respectively, and electric contact conduction of the main-grid-free back contact battery in the laser-induced sintering process is achieved. The electric contact structure suitable for the back contact battery is simple in structure, convenient to use and capable of effectively improving the power connection and conduction quality of the battery piece, avoiding contact short circuit between grid lines with different polarities, improving the processing quality of the main-grid-free back contact battery and reducing the processing cost of the back contact battery.

Description

Technical Field

[0001] This utility model belongs to the field of solar cell manufacturing technology, specifically relating to an electrical contact structure and laser-induced sintering system suitable for back-contact batteries. Background Technology

[0002] In the process of manufacturing solar cells using laser-induced sintering (LIF) technology, a reverse bias voltage needs to be applied to the cell to complete the operation. For conventional back-contact (BC) cells, the conductive electrodes include not only fine grids but also main grids, with connection points (PADs) distributed on the main grids. In this case, by using probes of different polarities to contact the corresponding PADs, the power application requirements of the laser-induced sintering process can be met, and the entire conduction process is relatively simple to implement.

[0003] With increasing pressure to reduce costs and increase efficiency in the photovoltaic industry, busbar-less (OBB) technology has emerged. This significantly reduces the amount of conductive electrode metallization material used, reduces recombination and shading area, and improves the conversion efficiency of solar cells. However, for busbar-less back-contact (OBB-BC) cells, since the distance between adjacent fine grids is usually less than 1 mm and the adjacent fine grids have opposite polarities, using conventional probe pressing methods to connect the cell grid lines is prone to short-circuit problems.

[0004] In addition, since back-contact batteries often have a hot spot protection design, the leakage current level is relatively large. When laser-induced sintering process is applied, the circuit current will increase, which also puts forward new requirements for the current carrying capacity of the electrical contact structure. Utility Model Content

[0005] In view of one or more of the above-mentioned defects or improvement needs of the prior art, this utility model provides an electrical contact structure and laser-induced sintering system suitable for back contact batteries, which can accurately meet the electrical contact requirements of back contact batteries during laser-induced sintering process, avoid short circuit problems between grid lines of different polarities, and improve the processing efficiency and quality of back contact batteries.

[0006] To achieve the above objectives, one aspect of this utility model provides an electrical contact structure suitable for back-contact batteries, comprising at least one P-region metal plate and at least one N-region metal plate; the at least one P-region metal plate is used to abut against all P-region grid lines on the battery cell; the at least one N-region metal plate is used to abut against all N-region grid lines on the battery cell.

[0007] Each metal plate includes a metal substrate and a plurality of spaced metal protrusions that protrude from one end face of the metal substrate; the two metal plates can be spaced apart in a first direction when they abut against the battery cell, and the metal protrusions on the P-region metal plate and the metal protrusions on the N-region metal plate are staggered in a second direction.

[0008] Multiple metal protrusions on the same metal plate are spaced apart in a second direction, and each metal protrusion on the same metal plate is used to abut against the same type of grid lines spaced apart along the second direction on the battery cell; wherein, the second direction is perpendicular to the first direction.

[0009] As a further improvement of this utility model, the part of the electrical contact structure used for receiving electricity is located on the end face of the metal substrate away from the metal protrusion, and the area of ​​the end face of the metal substrate away from the metal protrusion is greater than the sum of the areas of the contact surfaces of all the metal protrusions on the metal substrate.

[0010] or

[0011] The portion of the electrical contact structure used for electrical connection is located on the side wall of the metal substrate, and the cross-sectional area of ​​the side wall is not less than 1.5 mm². 2 .

[0012] As a further improvement of this utility model, the width of the contact surface of the metal protrusion used to abut the grid line is 30μm~500μm;

[0013] and / or

[0014] The metal protrusions are provided with a gold layer on the contact surface of the grid lines.

[0015] and / or

[0016] The contact surface of the metal protrusion used to abut the grid line is either flat or curved.

[0017] As a further improvement of this utility model, an insulating layer is provided in the space between two adjacent metal protrusions, which is either a hollow area or the space between two adjacent metal protrusions.

[0018] and / or

[0019] The metal protrusions are formed by etching on a metal plate using photolithography, or by depositing on a metal plate using mask electroplating or PVD deposition techniques.

[0020] As a further improvement of this utility model, the metal protrusion for contacting and communicating with the same grid line includes a plurality of protrusion units spaced apart along a first direction, and the centers of at least two of the protrusion units are offset in a second direction.

[0021] As a further improvement of this utility model, the offset distance between the two mutually offset protruding units in the second direction does not exceed 10μm.

[0022] As a further improvement of this utility model, there are multiple P-region metal plates and / or N-region metal plates, and the two types of metal plates of different types are alternately spaced along the first direction and the two types of grid lines are respectively connected.

[0023] As a further improvement of this utility model, in multiple metal plates of the same type, each metal substrate has metal protrusions for all grid lines of the same type, and the distance between adjacent metal protrusions on the same metal plate is equal to the distance between adjacent grid lines of the same polarity, so that each metal plate can simultaneously conduct all grid lines of the same type after abutting the battery cell.

[0024] or

[0025] In multiple metal plates of the same type, each metal substrate has metal protrusions for a portion of the grid lines of the same type, and the distance between at least some adjacent metal protrusions on the same metal plate is N times the distance between adjacent grid lines of the same polarity, where N is a natural number not less than 2; then, multiple metal plates of the same type can simultaneously abut against the battery cell to connect and conduct all the grid lines of the same type.

[0026] As a further improvement of this utility model, the cross-sectional shape of the metal protrusion is rectangular, or trapezoidal, or the side of the cross-section is arc-shaped, or the bottom surface of the area between two adjacent metal protrusions is curved.

[0027] As a further improvement of this utility model, the metal plate is made of copper.

[0028] As a further improvement of this utility model, it also includes a base plate located below the metal substrate facing away from the metal protrusion end face, and an elastic member connecting the base plate and the metal substrate facing away from the metal protrusion end face.

[0029] Another aspect of this utility model also provides a laser-induced sintering system, which includes the aforementioned electrical contact structure suitable for back contact batteries, and further includes a laser processing module, an adsorption and transfer mechanism, a visual inspection mechanism, and a position correction mechanism.

[0030] The adsorption and transfer mechanism is used to fix and place the battery cell to be processed. It includes a rotary drive mechanism and multiple hollowed-out support platforms connected to the rotary drive mechanism. The laser-induced sintering system has an imaging position and a processing position. The rotary drive mechanism drives the support platforms to pass through the imaging position and the processing position in sequence. The laser processing module and the electrical contact structure are both located at the processing position. The laser processing module is located above the support platform, and the electrical contact structure is located below the support platform at the corresponding hollowed-out position. The laser processing module is used to emit a laser beam to scan the battery cell while a reverse voltage is applied to the battery cell through the electrical contact structure.

[0031] The visual inspection mechanism is located at the imaging position and includes a camera inspection system located below the support platform, used to acquire the relative position data of the battery cells placed on the adsorption and transfer mechanism;

[0032] The position correction mechanism is connected to the electrical contact structure and is used to adjust the position of the electrical contact structure according to the relative position data of the battery cells.

[0033] As a further improvement of this utility model, it also includes a support device set at the processing position. The support device includes a transparent support plate and a lifting mechanism connected to the transparent support plate. The lifting mechanism is used to drive the transparent support plate closer to or away from the carrier platform. The transparent support plate is located below the laser processing module and above the adsorption and transfer mechanism.

[0034] The aforementioned improved technical features can be combined with each other as long as they do not conflict with each other.

[0035] In summary, the beneficial effects of the above-described technical solutions conceived by this utility model compared with the prior art include:

[0036] This invention relates to an electrical contact structure applicable to back-contact batteries. Its structure is simple, consisting of an N-region metal plate corresponding to the N-region grid lines on the battery cell and a P-region metal plate corresponding to the P-region grid lines. Metal protrusions on these two metal plates, corresponding to the two types of grid lines, allow the two metal plates to conduct electricity to all N-region and P-region grid lines on the battery cell after contacting it. This achieves electrical contact conductivity in gridless back-contact batteries during laser-induced sintering, improving the battery cell's electrical conductivity quality and preventing short circuits between grid lines of different polarities. The N-region metal plate connects to the positive terminal of the power supply, and the P-region metal plate connects to the negative terminal. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0038] Figure 1 This is a schematic diagram of the metal plate structure of the electrical contact structure applicable to the back contact battery in this embodiment of the present invention.

[0039] Figure 2 This is a schematic diagram of the end face of the solar cell to be connected for laser-induced sintering process in an embodiment of this utility model.

[0040] Figure 3 This is a schematic diagram of the structure of the battery cells connected by a metal plate in an embodiment of this utility model;

[0041] Figure 4 This is a schematic diagram of an embodiment of the present invention where a single metal protrusion is configured as multiple protrusion units;

[0042] Figure 5 This is a schematic diagram of an embodiment of the present invention in which multiple protruding units are arranged in a way that is offset from each other;

[0043] Figure 6 This is a schematic diagram of one embodiment of the present invention that utilizes multiple metal plates to conduct battery cells;

[0044] Figure 7 This is a schematic diagram of another embodiment of the present invention that utilizes multiple metal plates to conduct battery cells;

[0045] Figure 8 This is a schematic diagram of a contact surface groove being formed on the contact surface of a metal protrusion in an embodiment of this utility model.

[0046] In all the accompanying drawings, the same reference numerals denote the same technical features, specifically:

[0047] 100. Metal plate; 200. Battery cell;

[0048] 101. N-zone metal plate; 102. P-zone metal plate; 103. Metal substrate; 104. Metal protrusion; 105. Contact surface groove; 106. Cutout area;

[0049] 201, N-region gate line; 202, P-region gate line. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the present utility model and are not intended to limit the present utility model. Furthermore, the technical features involved in the various embodiments of the present utility model described below can be combined with each other as long as they do not conflict with each other.

[0051] In the description of this utility model, it should be understood that, unless otherwise explicitly specified and limited, the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0052] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0053] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0054] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0055] The following is for reference. Figures 1-8 This invention describes the electrical contact structure of a suitable back-contact battery according to an embodiment of the present invention.

[0056] Among them, a conventional gridless back-contact battery cell 200, such as Figure 2 As shown, two types of fine grid lines are arranged on one side (back side) of the battery cell 200. Exemplarily, these are N-region grid lines 201 and P-region grid lines 202. Both types of grid lines are multiple parallel lines spaced apart, and the N-region grid lines 201 and P-region grid lines 202 are alternately spaced apart. Exemplarily, among the multiple grid lines of the same type, the spacing between adjacent grid lines is equal.

[0057] The purpose of the electrical contact structure in the preferred embodiment is to simultaneously enable all N-region grid lines 201 and all P-region grid lines 202 on the battery cell 200 to be simultaneously turned on.

[0058] In a preferred embodiment, the electrical contact structure applicable to the back contact battery adopts a technical solution by setting multiple metal plates 100, which abut against the grid lines on the back of the battery cell 200 and are connected to electricity, thereby achieving simultaneous conduction of the two types of grid lines.

[0059] Considering that there are two types of grid lines, and each type of grid line needs to be conductive, the metal plate 100 provided in the preferred embodiment also has two types, and the total number of metal plates 100 of the two types is not less than two. The position of each metal plate 100 abutting against the grid line on the battery cell 200 can only be either the N-region grid line 201 or the P-region grid line 202, whichever is selected.

[0060] Specifically, the electrical contact structure includes at least one N-region metal plate 101 and at least one P-region metal plate 102. The at least one N-region metal plate 101 is used to abut against all N-region grid lines 201 on the battery cell 200, and the at least one P-region metal plate 102 is used to abut against all P-region grid lines 202 on the battery cell 200. When there is only one N-region metal plate 101, this single N-region metal plate 101 must be able to abut against all N-region grid lines 201 on the battery cell 200. If there are multiple N-region metal plates 101, it is not required that each N-region metal plate 101 abut against all N-region grid lines 201; it is sufficient that the sum of all N-region metal plates 101 abuts against all N-region grid lines 201 on the battery cell 200.

[0061] like Figure 1 As shown, each metal plate 100 includes a metal substrate 103 and a plurality of spaced metal protrusions 104 protruding from one end face of the metal substrate 103. A cutout area 106 is formed between two adjacent metal protrusions 104. The cutout area 106 can be empty or an insulating layer can be provided within it. After two adjacent metal protrusions 104 abut against two grid lines of the same type, the cutout area 106 can be used to avoid misalignment between different types of grid lines between the two metal protrusions 104. In actual installation, the metal protrusions 104 located at the ends of the metal plates 100 can be flush with their sidewalls or located within the sidewalls of the metal substrate 103 as needed.

[0062] More specifically, the metal substrate 103 is used to support and electrically conduct each metal protrusion 104, and the metal substrate 103 is provided with a part for connecting to electricity, so that the metal substrate 103 can be connected to the positive or negative terminal of the power supply, so that after the metal plate 100 abuts against the grid line of the conducting battery cell 200 through each metal protrusion 104, the corresponding grid line on the battery cell 200 can be connected to electricity.

[0063] More specifically, when the two metal plates 100 abut and mate with the battery cell 200, the two metal substrates 103 are spaced apart in a first direction, and the metal protrusions 104 on the N-region metal plate 101 and the metal protrusions 104 on the P-region metal plate 102 are spaced apart in a second direction; wherein, the first direction is parallel to the grid line extension direction, and the second direction is perpendicular to the first direction. Figure 2 Taking the battery cell 200 as an example, the first direction mentioned above is the vertical direction shown in the figure, and the second direction is the horizontal direction shown in the figure.

[0064] Meanwhile, multiple metal protrusions 104 on the same metal plate 100 are spaced apart in the second direction, and each metal protrusion 104 on the same metal plate 100 is used to abut against the same type of grid lines spaced apart along the second direction on the battery cell 200.

[0065] During the electrical conduction operation, the two metal plates 100 are matched with the battery cell 200 by being spaced apart in a first direction and their respective metal protrusions 104 abut against the two grid lines on the conducting battery cell 200.

[0066] As one possible conduction method, in a preferred embodiment, the metal plate 100 includes an N-region metal plate 101 and a P-region metal plate 102, such as Figure 3 As shown. The metal substrate 103 of the N-region metal plate 101 is provided with metal protrusions 104 that abut against all N-region grid lines 201 on all battery cells 200, and the metal substrate 103 of the P-region metal plate 102 is provided with metal protrusions 104 that abut against all P-region grid lines 202 on all battery cells 200.

[0067] During actual conduction, the two metal plates 100 approach and abut against the grid lines on the back of the battery cell 200. The metal protrusions 104 on the N-region metal plate 101 abut against and conduct all the N-region grid lines 201 on the battery cell 200, and the metal protrusions 104 on the P-region metal plate 102 abut against and conduct all the P-region grid lines 202 on the battery cell 200. Simultaneously, to avoid short circuits between the two metal plates 100, they are spaced apart in the first direction. For example, in... Figure 3 In the preferred embodiment shown, the two metal plates 100 are positioned at both ends of the battery cell 200 in the first direction.

[0068] It should be noted that the conduction of the aforementioned gate lines does not mean that each area along the extension length of each gate line needs to be in contact with the metal protrusion 104. It is sufficient that a portion of each gate line is in contact with the metal protrusion 104, rather than the entire gate line being in contact with the metal protrusion 104.

[0069] Furthermore, to avoid electrical connection interruption due to broken grid lines, the metal protrusions 104 can be segmented or the length of the metal protrusions 104 that abut against and conduct through each grid line can be increased.

[0070] As another possible conduction method, in the preferred embodiment, there are at least two metal plates 100, and the battery cell 200 simultaneously abuts and conducts with more than two metal plates 100. In this case, the multiple metal plates 100 are spaced apart in the first direction and conduct the two types of grid lines respectively. In actual installation, it is further preferred that the two types of metal plates 100 of different types are alternately arranged in the first direction, such as... Figure 6 , Figure 7 As shown in the image.

[0071] It should be noted that the electrical contact structure of this application is not only applicable to standard single-cell solar cells, but also to multi-cell solar cells, such as two-cell, three-cell, or more cells. When used for multi-cell solar cells, each cell requires at least one P-region metal plate 102 and at least one N-region metal plate 101. As one example, when multiple cells are arranged along a first direction, all corresponding metal plates 100 are spaced apart in the first direction and conduct the two types of grid lines on all cells respectively.

[0072] As one configuration, in multiple metal plates of the same type, each metal plate 100 has metal protrusions 104 for all grid lines of the same type (N-area grid line 201 or P-area grid line 202). That is, the number of metal protrusions 104 on each metal plate 100 is the same as the number of all N-area grid lines 201 or all P-area grid lines 202 on a battery cell 200, and the distance between adjacent metal protrusions 104 on each metal plate 100 is equal to the distance between adjacent grid lines of the same type.

[0073] For example, in such Figure 6 In the preferred embodiment shown, there are three N-region metal plates 101 and three P-region metal plates 102, and the number of metal protrusions 104 on each metal plate 100 of the same polarity is equal, which is equal to the number of grid lines of that polarity on the battery cell 200. Furthermore, when the metal plates 100 abut against the battery cell 200, the three N-region metal plates 101 and the three P-region metal plates 102 are alternately spaced in the first direction.

[0074] As another configuration, in multiple metal plates of the same type, each metal plate 100 has metal protrusions 104 for the same type of grid line (N-area grid line 201 or P-area grid line 202). That is, the number of metal protrusions 104 on at least some metal plates 100 is less than the number of all N-area grid lines 201 or all P-area grid lines 202 on a corresponding battery cell 200. At this time, the hollow area 106 between at least some adjacent metal protrusions 104 faces at least three grid lines. In other words, the distance between at least some adjacent metal protrusions 104 in the second direction is N times the distance between two adjacent grid lines of the same polarity, where N is a natural number not less than 2. Meanwhile, among the multiple metal plates 100 of the same polarity, at least two of the metal plates 100 have metal protrusions 104 with different positions, and ensure that when the multiple metal plates 100 of the same polarity simultaneously abut against the matching battery cell 200, all grid lines of the same polarity can be abutted and connected by the metal protrusions 104 distributed on the multiple metal plates 100, that is, each grid line is abutted.

[0075] In the above configuration, by increasing the spacing between two adjacent metal protrusions 104 in the second direction, the reliability of the metal plate 100 in use can be further improved, and the probability of short circuit in the metal plate 100 can be reduced. In addition, by optimizing the number of metal plates 100 with the same polarity, the requirement that the same grid line and multiple metal protrusions 104 simultaneously abut and conduct can be met can be achieved, thereby avoiding the impact of grid breakage.

[0076] For example, in such Figure 7 In the preferred embodiment shown, both types of metal plates 100 include three metal plates 100 with different configurations, namely, N-region metal plates 101a, 101b, and 101c, and P-region metal plates 102a, 102b, and 102c. The two types of metal plates 100 are spaced apart in the first direction, and simultaneously achieve the abutment and conduction of all grid lines in the two polarity grid lines.

[0077] It should be noted that the length of the metal protrusion 104 on a metal plate 100 along the first direction can be less than, equal to, or greater than the length of the metal substrate 103 in the first direction. Generally, to facilitate the fabrication of the metal protrusion 104, it is preferable that the length of the metal substrate 103 in the first direction is greater than or equal to the length of the metal protrusion 104 in the first direction. This also improves the current withstand capability of the electrical contact structure when power is applied from the bottom of the metal substrate 103. Furthermore, it should be noted that when the length of the metal substrate 103 in the first direction is less than the length of the metal protrusion 104 in the first direction, the protruding length of the metal protrusion 104 is less than the spacing in the first direction when the two metal substrates 103 are adjacent and matched on the battery cell 200. This prevents the protruding end of the metal protrusion 104 from short-circuiting due to contact with the edge of the adjacent metal substrate 103.

[0078] Furthermore, to improve the conductivity of the metal protrusion 104, its configuration can be optimized.

[0079] For example, in a preferred embodiment, it is preferable to ensure that the width of the contact surface of the metal protrusion 104 for abutting the grid line (i.e., the size of the contact surface in the second direction) is 30μm to 500μm. This range is set according to the width of the grid line. This range can also prevent short circuits between adjacent P-region electrodes and N-region electrodes of the battery cell, while ensuring that the grid line of the battery cell has a large contact area with the metal contact area, thereby improving the current withstand value.

[0080] Furthermore, since back-contact batteries often have anti-hotspot designs, their leakage current is relatively high. When laser-induced sintering is applied, the circuit current will exceed 10A, which places new demands on the current withstand capability of the electrical contact structure. Preferably, the electrical contact structure in this embodiment not only ensures precise contact between each fine grid on the battery cell 200 and the corresponding metal protrusion 104, but also improves its current withstand value.

[0081] Considering that the electrical contact structure of the application can be energized either on the side of the metal substrate 103 or on the bottom surface of the metal substrate 103 (the end face away from the metal protrusion 104), the requirements for improving the current withstand value differ depending on the energizing location. Furthermore, the portion of the electrical contact structure used for energizing can be located on the end face of the metal substrate 103 away from the metal protrusion 104 (i.e., end face energizing) or on any side wall of the metal substrate 103 (i.e., side energizing).

[0082] In the case of end-face electrification, the area of ​​the end face of the metal substrate 103 facing away from the metal protrusions is greater than the sum of the contact areas of all the metal protrusions 104 on the metal substrate 103. In this case, compared with the technical solution without a metal substrate, the current withstand value of the electrical contact structure will inevitably be significantly increased.

[0083] For side-mounted electrical applications, to improve the current withstand capability of the electrical contact structure, in a preferred embodiment, the cross-sectional area of ​​the sidewall of the metal substrate 103 is not less than 1.5 mm². 2 This configuration ensures that when the metal substrate 103 is powered from the side, the electrical contact structure can withstand a current of at least 15A, meeting the instantaneous high current requirements of the laser-induced sintering process.

[0084] Furthermore, the metal protrusions 104 on a single metal plate 100 for the same grid line are configured as follows: Figure 4 As shown, the metal protrusion 104 corresponding to the same grid line includes a plurality of protrusion units spaced apart along the first direction. By using the spaced arrangement of the plurality of protrusion units, when the metal protrusion 104 abuts and conducts with a certain grid line, the plurality of protrusion units can abut against different parts on the axis of the grid line respectively, saving materials, reducing the weight of the metal plate 100, and ensuring the reliability of the metal plate 100 abutting and conducting as much as possible.

[0085] It is understandable that the aforementioned arrangement of a single metal protrusion 104 divided into multiple protrusion units can also be applied to... Figure 6 or Figure 7 The technical solutions shown will not be elaborated upon here.

[0086] More specifically, for Figure 4 The arrangement of the multiple protruding units shown can be further transformed into, for example... Figure 5 In this form, among the multiple protrusion units of the same metal protrusion 104, the centers of at least two protrusion units are offset in the second direction.

[0087] by Figure 5 Taking the illustrated technical solution as an example, the metal protrusion 104 for the same gate line includes three protrusion units 104a, 104b, and 104c with parallel axes. Relative to protrusion unit 104b, the center of protrusion unit 104a is offset to the left by a distance... w The center of the protruding unit 104c is offset to the right by a distance. w .

[0088] By offsetting each protruding unit in the second direction, a certain lateral deviation exists between the centers of each protruding unit; this arrangement better meets the positioning requirements of the electrical contact structure. In actual installation, the center offset distance between two offset protruding units in the second direction does not exceed 10μm.

[0089] For example, in a preferred embodiment, a gold layer (such as an Au plating layer applied by electroplating) is preferably provided on the contact surface of the metal protrusion 104 for abutting the gate line, in order to improve the conductivity and oxidation resistance of the conductive plane.

[0090] Meanwhile, in actual setup, the contact surface of the metal protrusion 104 used to abut the grid line can be set as a plane or a curved surface. The curved surface can be set as a raised curved surface or a concave curved surface.

[0091] In actual setup, the concave curved surface is set as follows: Figure 8 As shown, a contact surface groove 105 is formed on the side of the metal protrusion 104 facing away from the metal substrate 103. Simultaneously, the maximum depth of the contact surface groove 105 is... h The depth H is less than 106 of the hollow area.

[0092] More preferably, an insulating layer is provided (e.g., filled) in the space between two adjacent metal protrusions 104, that is, the hollow area 106, so as to prevent the fine gate of the opposite electrode from contacting the metal substrate 103.

[0093] More specifically, in the preferred embodiment, the metal protrusion 104 is preferably formed by etching on the metal plate 100 using photolithography, or the metal protrusion 104 is preferably formed by depositing on the metal substrate 103 using mask electroplating or PVD deposition technology.

[0094] In addition, for the metal protrusion 104 in the preferred embodiment, its cross-sectional shape can preferably be rectangular or trapezoidal, or the side of the cross-section can be arc-shaped, or the bottom surface of the area between two adjacent metal protrusions 104 can be curved. That is, the structure and combination of the metal protrusion 104 and two adjacent metal protrusions 104 can be diversified.

[0095] In actual installation, the material of the metal plate 100 can be determined as needed. For example, in a specific preferred embodiment, the metal plate 100 is made of copper, which has good electrical conductivity and is inexpensive.

[0096] Furthermore, the electrical contact structure also includes a base plate located below the metal substrate facing away from the metal protrusion end face, and an elastic element connecting the base plate and the metal substrate facing away from the metal protrusion end face. This elastic element, for example, is a spring. By providing the elastic element, a buffering effect can be achieved when the electrical contact structure abuts against the grid lines on the back of the battery cell, preventing the metal protrusion from making hard contact with the grid lines and preventing battery fragmentation. When the electrical contact structure is connected to the position correction mechanism described below, the base plate is a component of the position correction mechanism.

[0097] As another aspect of this utility model, based on the aforementioned electrical contact structure, a laser-induced sintering system is also proposed for laser-induced sintering of the battery cells in back contact with the battery.

[0098] Specifically, the laser-induced sintering system in the preferred embodiment includes the aforementioned electrical contact structure, as well as a laser processing module, an adsorption and transfer mechanism, a visual inspection mechanism, and a position correction mechanism.

[0099] The electrical contact structure includes at least one N-region metal plate 101 and at least one P-region metal plate 102. The metal substrate 103 of each N-region metal plate 101 is connected to the positive terminal of an external power supply, and the metal substrate 103 of each P-region metal plate 102 is connected to the negative terminal of an external power supply.

[0100] Meanwhile, in the preferred embodiment, the adsorption and transfer mechanism is used to fix and place the battery cell 200 to be laser-induced sintering. In the preferred embodiment, the adsorption and transfer mechanism is a conventional turntable device, which includes a rotary drive mechanism and multiple support platforms connected to the rotary drive mechanism. Each support platform is hollowed out to facilitate the metal plate 100 to abut against the back of the battery cell 200 from below, and to facilitate visual inspection by the camera from below.

[0101] The laser-induced sintering system has an imaging position and a processing position. The rotary drive mechanism drives the carrier stage to pass through the imaging position and the processing position in sequence. The laser processing module and the electrical contact structure are both located in the processing position. The laser processing module is located above the carrier stage, and the electrical contact structure is located below the carrier stage at the corresponding hollow position. The laser processing module is used to emit a laser beam to scan the battery while the battery is being subjected to a reverse voltage through the electrical contact structure.

[0102] Furthermore, in the preferred embodiment, the visual inspection mechanism is located at the photographing position and includes a camera inspection system located below the support platform. The camera inspection system is used to identify position recognition points or battery edge positions on the battery cell to obtain relative position data of the battery cell 200.

[0103] More specifically, the position correction mechanism is connected to the electrical contact structure and is used to change the relative position of the metal plates 100 according to the relative position data of the battery cells 200 obtained by the vision inspection system, thereby aligning the metal protrusions with the grid lines on the back of the battery. In specific operation, the position correction mechanism receives the relative position data of the battery cells 200 obtained by the vision inspection mechanism and adjusts the position of each metal plate 100 according to the relative position data, thereby achieving precise alignment of the metal protrusions 104 on each metal plate 100 with the corresponding polarity grids on the battery cells 200. The position correction mechanism can be a conventional structure in the prior art, such as a UVW alignment platform.

[0104] Furthermore, the laser-induced sintering system in the preferred embodiment also includes a support device disposed at the processing position. The support device includes a transparent support plate and a lifting mechanism connected to the transparent support plate. The lifting mechanism is used to drive the transparent support plate closer to or away from the carrier platform. The transparent support plate is located below the laser processing module and above the adsorption and transfer mechanism. By setting the transparent support plate, it can provide support when the electrical contact device rises to contact the battery, achieving close contact between the metal protrusion and the battery cell. At the same time, the transparent form of the support plate allows the laser beam to pass through and scan the battery cell for processing. In actual installation, the front support device of the battery cell is preferably a quartz glass plate, which has good heat resistance, high strength, and high spectral transmittance, and can meet the requirements of scanning the battery cell by lasers of various wavelengths.

[0105] By utilizing the corresponding settings of the laser-induced sintering system, the laser-induced sintering process of the solar cell 200 can be realized.

[0106] This invention relates to an electrical contact structure applicable to back-contact batteries. The structure is simple, consisting of an N-zone metal plate corresponding to the N-zone grid lines on the battery cell and a P-zone metal plate corresponding to the P-zone grid lines. The N-zone metal plate is connected to the positive terminal of the power supply, and the P-zone metal plate is connected to the negative terminal. Metal protrusions and hollow areas on the two metal plates, corresponding to the two types of grid lines, allow the two metal plates to conduct electricity to all N-zone and P-zone grid lines on the battery cell after contacting it. This achieves electrical contact conduction in the laser-induced sintering process of the gridless back-contact battery, improving the electrical conductivity quality of the battery cell and preventing short circuits between grid lines of different polarities.

[0107] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An electrical contact structure for a back contact cell, characterized by The metal plates include at least one P-zone metal plate and at least one N-zone metal plate; the at least one P-zone metal plate is used to abut all P-zone grid lines on a cell; the at least one N-zone metal plate is used to abut all N-zone grid lines on the cell; Each metal plate includes a metal substrate and a plurality of spaced metal protrusions protruding from one side end surface of the metal substrate; the two types of metal plates can be spaced in the first direction when abutting the cell, and the metal protrusions on the P-zone metal plate and the metal protrusions on the N-zone metal plate are staggered in the second direction; The plurality of metal protrusions on the same metal plate are spaced in the second direction, and each metal protrusion on the same metal plate is used to abut the same type of grid lines spaced in the second direction on the cell; wherein the second direction is perpendicular to the first direction.

2. The electrical contact structure for a back contact cell as claimed in claim 1, wherein, The part for electrical connection on the electrical contact structure is provided on the end surface of the metal substrate away from the metal protrusions, and the area of the end surface of the metal substrate away from the metal protrusions is greater than the sum of the areas of the contact surfaces of all the metal protrusions on the metal substrate. Or The part for electric connection on the electric contact structure is arranged on the side wall surface of the metal substrate, and the cross-sectional area of the side wall surface is not less than 1.5mm 2 .

3. The electrical contact structure for a back contact cell as claimed in claim 1, wherein, The width of the contact surface of the metal protrusion for abutting the grid line is 30 μm to 500 μm; And / or The contact surface of the metal protrusion for abutting the grid line is provided with a gold layer; And / or The contact surface of the metal protrusion for abutting the grid line is a plane or a curved surface.

4. The electrical contact structure for a back contact cell as claimed in any one of claims 1 to 3, wherein, The space between the two adjacent metal protrusions is a hollow area or provided with an insulating layer. And / or The metal protrusion is formed by etching on the metal plate through a photolithography technique, or the metal protrusion is formed by depositing on the metal plate through a mask plating or PVD deposition technique.

5. The electrical contact structure for a back contact cell of claim 1, wherein, The metal protrusion for abutting the same grid line includes a plurality of protrusion units spaced in the first direction, and the centers of at least two protrusion units are offset in the second direction.

6. The electrical contact structure for a back contact cell as claimed in claim 5, wherein, The offset distance between the two offset protrusion units in the second direction is not more than 10 μm.

7. The electrical contact structure for a back contact cell as claimed in any one of claims 1 to 3, 5, 6, wherein, The P-zone metal plate and / or the N-zone metal plate is a plurality of plates, and the two types of metal plates of different types are alternately spaced in the first direction and conduct the two types of grid lines respectively.

8. An electrical contact structure for a back contact cell as defined in claim 7, characterized in that In a plurality of metal plates of the same type, each metal substrate is provided with metal protrusions for all grid lines of the same type, and the distance between the adjacent metal protrusions on the same metal plate is equal to the distance between the adjacent grid lines of the same polarity, so that each metal plate can simultaneously conduct all grid lines of the same type after abutting the cell. Or In a plurality of metal plates of the same type, each metal substrate is provided with metal protrusions for part of the grid lines of the same type, and the distance between at least part of the adjacent metal protrusions on the same metal plate is N times the distance between the adjacent grid lines of the same polarity, N being a natural number not less than 2; then a plurality of metal plates of the same type can simultaneously abut the cell to abut and conduct all grid lines of the same type.

9. The electrical contact structure for a back contact cell of claim 1 wherein, The cross-sectional shape of the metal protrusion is rectangular or trapezoidal, or the side of the cross section is arc-shaped, or the bottom surface of the area between the two adjacent metal protrusions is curved.

10. The electrical contact structure for back contact cells as claimed in claim 1, wherein, The material of the metal plate is copper.

11. The electrical contact structure for back contact cells as claimed in claim 1, wherein, The back plate is arranged below the metal substrate away from the metal protrusion end face, and the elastic member is connected between the back plate and the metal substrate away from the metal protrusion end face.

12. A laser-induced sintering system, characterized by The electric contact structure of the back contact battery comprises the electric contact structure of any one of claims 1-11, a laser processing module, an adsorption and transfer mechanism, a visual detection mechanism, and a position correction mechanism. The adsorption and transfer mechanism is used for fixing and placing the battery piece to be processed, and comprises a rotating driving mechanism and a plurality of hollow bearing tables connected to the rotating driving mechanism; the laser-induced sintering system has a photographing position and a processing position; the rotating driving mechanism drives the bearing tables to pass through the photographing position and the processing position in sequence; the laser processing module and the electric contact structure are located in the processing position; the laser processing module is located above the bearing tables, and the electric contact structure is located below the bearing tables at a position corresponding to the hollow part; the laser processing module is used for emitting a laser beam to scan the battery piece while the battery piece is applied with a reverse voltage by the electric contact structure; The visual detection mechanism is located at the photographing position and comprises a camera detection system located below the bearing tables, which is used for acquiring relative position data of the battery piece placed on the adsorption and transfer mechanism; The position correction mechanism is connected with the electric contact structure and is used for adjusting the position of the electric contact structure according to the relative position data of the battery piece.

13. The laser-induced sintering system of claim 12, wherein The support device is arranged at the processing position and comprises a transparent support plate and a lifting mechanism connected with the transparent support plate; the lifting mechanism is used for driving the transparent support plate to approach or move away from the bearing tables; the transparent support plate is located below the laser processing module and above the adsorption and transfer mechanism.

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