An electrical connection structure for a back contact battery

Abstract

This utility model discloses an electrical connection structure for a back-contact battery, belonging to the technical field of back-contact battery technology. It includes an insulating substrate and multiple electrical contacts and conductive circuits disposed on the front and back sides of the insulating substrate. By creating conductive holes in the insulating substrate and placing conductive elements within these holes, with the top of the conductive element serving as an electrical contact, the conductive elements connect multiple electrical contacts to the same conductive circuit. These contacts then abut against the grid lines of the back-contact battery. Different conductive circuits then connect to the positive and negative terminals of an external power source, thereby achieving electrical connection of the back-contact battery grid lines. This electrical connection structure solves the electrical contact problem during grid line conduction in back-contact batteries, ensuring the accuracy and quality of grid line conduction while avoiding battery fragmentation or microcracks caused by uneven pressure distribution. It also improves the convenience of back-contact battery processing and testing, and reduces the processing and application costs of back-contact batteries.

Description

Technical Field

[0001] This utility model belongs to the technical field of back contact batteries, specifically relating to an electrical connection structure for back contact batteries. Background Technology

[0002] A back-contact cell (BC) is a type of battery in which both the PN junction and the metal electrodes are located on the back side, allowing for greater utilization of incident light and reduced optical losses. The back of a BC features an alternating arrangement of fine grids for the positive and negative electrodes, forming a dense network. While this layout helps improve battery efficiency and aesthetics, it also presents challenges for applications requiring a closed circuit, such as testing the battery's electrical performance, electroluminescence (EL) measurement, laser-induced sintering (LIF) treatment, and quantum response (QE) testing.

[0003] Traditional electrical conduction methods mostly employ probe bonding, which exerts significant pressure on the battery and is prone to fragmentation. This is especially true for gridless (OBB) structures that only contain fine grids and no main grid. When using traditional probe bonding for testing, since OBB-BC batteries lack a main grid line, at least one probe must be placed for each fine grid to ensure conduction, leading to a high demand for probes. Furthermore, because the distance between adjacent fine grids is often very small, while the mounting portion of conventional probes is typically large, this easily causes short circuits between the positive and negative electrodes, and the high-density probe layout also increases alignment complexity. Additionally, to ensure good electrical contact, appropriate pressure must be applied during probe bonding for conduction; however, traditional probe bonding methods struggle to apply pressure uniformly, potentially leading to battery fragmentation or microcracks.

[0004] Therefore, there is an urgent need to develop a power supply structure for back-contact batteries to solve the above-mentioned problems in the existing technology, thereby achieving a more efficient and reliable electrical connection, while reducing the number of probes and preventing short-circuit risks, and thus supporting the performance evaluation and processing of back-contact batteries in various application scenarios. Utility Model Content

[0005] In response to one or more of the above-mentioned defects or improvement needs of the prior art, this utility model provides an electrical connection structure for back contact batteries, which can efficiently and reliably achieve electrical conduction of back contact batteries, avoid the short circuit risk of traditional probe pressing methods, and support the performance evaluation and processing of back contact batteries in various application scenarios.

[0006] To achieve the above objectives, this utility model provides an electrical connection structure for a back contact battery, comprising:

[0007] An insulating substrate, wherein a plurality of first and second through holes are spaced apart on the insulating substrate and penetrate its front and back sides, the positions of the first and second through holes corresponding to the positive grid line and the negative grid line of the back contact battery, respectively.

[0008] The conductive element includes a plurality of first electrical conductive elements and a plurality of second electrical conductive elements, which are respectively embedded in the first conductive hole and the second conductive hole;

[0009] The top of the conductive element is a contact portion, and each contact portion protrudes or is flush with the front side of the insulating substrate; the top of the first electrical conductive element is a first electrical contact portion, and the top of the second electrical conductive element is a second electrical contact portion. The first electrical contact portion and the second electrical contact portion are respectively used to contact the positive grid line and the negative grid line of the back contact battery.

[0010] The conductive circuit, located on the back side of the insulating substrate, includes a first circuit and a second circuit that can be electrically connected to electrodes of different polarities of an external power source. The first circuit is connected to at least a portion of the first conductive element, and the second circuit is connected to at least a portion of the second conductive element.

[0011] As a further improvement of this utility model, the through hole is an elongated through hole, the conductive element is elongated, and the contact portion at the top of the conductive element is elongated.

[0012] Alternatively, the through hole is a cylindrical hole, and the contact portions on two adjacent through members are spaced apart;

[0013] Alternatively, the through hole is a columnar hole, with multiple through holes corresponding to the same grid line, and the contact portions on the multiple through holes corresponding to the same grid line are connected as a whole in an elongated shape.

[0014] As a further improvement of this utility model, the contact portion is integrally formed with or separately formed from other parts of the conductive component.

[0015] As a further improvement of this utility model, the insulating substrate is a glass plate, FR-4 plate, ceramic substrate, CEM-3 plate, polyimide plate, PTFE plate or Rogers plate;

[0016] and / or

[0017] The thickness of the insulating substrate is 0.2mm to 10mm;

[0018] and / or

[0019] The surface of the contact portion protrudes from the front side of the insulating substrate, and the protrusion height is 5μm~100μm.

[0020] As a further improvement of this utility model, the portion of the insulating substrate without a contact portion is made hollow or made of a transparent material.

[0021] As a further improvement of this utility model, the portion of the insulating substrate without a contact portion is provided with an adsorption hole, and the insulating substrate is provided with an adsorption channel communicating with the adsorption hole.

[0022] As a further improvement of this utility model, the width of the contact portion is greater than the width of other parts of the conductive element;

[0023] and / or

[0024] The contact portion is used to contact the grid wires. The conductive surface is either a plane or a curved surface.

[0025] As a further improvement of this utility model, the width of the contact portion is between 10μm and 500μm.

[0026] As a further improvement of this utility model, the contact portion includes a metal protrusion and a surface coating disposed on the surface of the metal protrusion, the surface coating being used to contact the battery cell grid lines.

[0027] As a further improvement of this utility model, the thickness of the surface coating is 10μm~200μm, and / or the material of the surface coating is gold.

[0028] As a further improvement of this utility model, the conductive element is made of any one of copper, aluminum, silver, gold, tungsten, titanium, and nickel, or an alloy thereof.

[0029] As a further improvement of this utility model, the conductive circuit is a wire, or the conductive circuit is made by spraying nano-conductive ink, electroplating a metal layer, or patterning a whole metal plate.

[0030] As a further improvement of this utility model, the through hole is a columnar hole, and the contact portions on two adjacent through members are spaced apart; wherein, among the contact portions on the insulating substrate used to contact the same gate line, at least two contact portions are offset along the extension direction perpendicular to the gate line.

[0031] As a further improvement of this utility model, it also includes an elastic device connected to the back side of the insulating substrate, which provides cushioning when the insulating substrate abuts against the grid lines on the battery cell with its contact portion.

[0032] The aforementioned improved technical features can be combined with each other as long as they do not conflict with each other.

[0033] In summary, the beneficial effects of the above-described technical solutions conceived by this utility model compared with the prior art include:

[0034] The electrical connection structure for back contact batteries in this invention can solve the electrical connection problem when the grid lines on the back of the back contact battery are connected by the common arrangement of multiple contact parts and conductive circuits on both the front and back sides of the insulating substrate. This ensures that the contact parts accurately contact the grid lines of the back contact battery, achieving a more efficient and reliable electrical connection. At the same time, it can also reduce the risk of short circuits.

[0035] Furthermore, by providing adsorption holes in areas on the surface of the insulating substrate where no contact portion is provided, battery fragmentation or microcracks caused by uneven pressure distribution can be avoided, improving the convenience of back contact battery processing and testing, and reducing the processing and application costs of back contact batteries. Attached Figure Description

[0036] 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.

[0037] Figures 1-5 This is a cross-sectional schematic diagram of five electrical connection structures in the embodiments of this utility model;

[0038] Figure 6 This is a front view of the electrical connection structure in Embodiment 1 of this utility model;

[0039] Figure 7 This is a schematic diagram of the back structure of the electrical connection structure in Embodiment 1 of this utility model;

[0040] Figure 8 This is a front view of the electrical connection structure in Embodiment 2 of this utility model;

[0041] Figure 9 This is a schematic diagram of the back structure of the electrical connection structure in Embodiment 2 of this utility model;

[0042] Figure 10 This is a front view of the electrical connection structure in Embodiment 3 of this utility model;

[0043] Figure 11 This is a schematic diagram of the back structure of the electrical connection structure in Embodiment 3 of this utility model;

[0044] In all the accompanying drawings, the same reference numerals denote the same technical features, specifically:

[0045] 1. Insulating substrate; 101. Through hole; 102. Embedded hole;

[0046] 2. Contact area; 201. Metal protrusion; 202. Surface coating;

[0047] 3. Conductor;

[0048] 4. Conducting circuit; 401. First circuit; 402. Second circuit. Detailed Implementation

[0049] 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.

[0050] 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.

[0051] 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 that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0052] 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.

[0053] 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.

[0054] The following is for reference. Figures 1-5 This invention describes an electrical connection structure for a back contact battery according to an embodiment of the present invention.

[0055] like Figures 1-5 As shown, the electrical connection structure for the back contact battery in this invention includes an insulating substrate 1 made of insulating material, and a plurality of through holes 101 penetrating both the front and back sides are spaced apart on the substrate 1. Among the plurality of through holes 101, there are first through holes and second through holes, and the positions of the two types of through holes correspond to the positive grid lines and negative grid lines on the back side of the back contact battery, respectively.

[0056] Meanwhile, each through hole 101 is respectively embedded with a conductive element 3, namely a first electrical conductive element embedded in the first through hole and a second electrical conductive element embedded in the second through hole, and there are multiple first electrical conductive elements and multiple second electrical conductive elements. Here, "embedded" means that the conductive element 3 can be directly manufactured in each through hole 101, or the conductive element 3 can be made and then embedded into the through hole 101.

[0057] Furthermore, the top of each conductive element 3 (located at one end of the front side of the insulating substrate 1) is a contact portion 2, and each contact portion 2 protrudes or is flush with the front side of the insulating substrate 1. Among them, the top of the first conductive element is the first electrical contact portion, and the top of the second conductive element is the second electrical contact portion, which are used to contact the positive grid line and the negative grid line of the back contact battery, respectively.

[0058] In addition, there are multiple first electrical contacts and multiple second electrical contacts, and each contact 2 is made of conductive material.

[0059] Furthermore, a conductive circuit 4 is provided on the back side of the insulating substrate 1 (the side facing away from the contact portion 2), and the conductive circuit 4 includes a first circuit 401 and a second circuit 402 that can be connected to electrodes of different polarities (positive or negative) of an external power supply. The first circuit 401 is connected to at least a portion of the end of the first conductive element facing away from the contact portion 2, and the second circuit 402 is connected to at least a portion of the end of the second conductive element facing away from the contact portion 2.

[0060] This configuration allows the insulating substrate 1 to conduct all grid lines of both types (all P-region grid lines and all N-region grid lines) to the positive and negative terminals of the external power supply via the first circuit 401 and the second circuit 402 when each contact portion 2 on its front side is in close contact with all grid lines on the back side of the battery.

[0061] In actual installation, the arrangement, quantity, and position of the first and second conductive elements on the insulating substrate 1 can be determined based on the extension form, quantity, and position of all the grid lines to be contacted on the back of the battery. It can be understood that the aforementioned grid lines to be contacted can be main grids, fine grids, or both main and auxiliary grids can be in contact simultaneously.

[0062] In a preferred embodiment, since there are multiple grid lines on the back side of the back contact battery, there are multiple first and second conductive elements on the insulating substrate 1. As an example, the first circuit 401 is connected to the ends (the ends away from the contact portions) of all the first conductive elements, and the second circuit 402 is connected to the ends of all the second conductive elements. However, as another example, when there are multiple conductive elements 3 on the insulating substrate 1 for the same grid line, the first circuit 401 can also be connected to the ends of some of the first conductive elements, and the second circuit 402 can be connected to the ends of some of the second conductive elements, as long as the contact portion 2 on the conductive element 3 can achieve a reliable electrical connection with all the grid lines that need to be contacted. In addition, by setting the number of first and second conductive elements on the insulating substrate 1 to multiple, different grid line patterns of the back contact battery can also be accommodated. In this case, it is only necessary to connect the first circuit 401 and the second circuit 402 to the conductive elements 3 at the corresponding arrangement positions according to the grid line pattern.

[0063] Furthermore, considering that both the main grid lines and sub-grid lines on the back of the battery are strip-shaped, when actually opening the through-hole 101, the through-hole 101 can be multiple spaced columnar holes or elongated strip-shaped holes. Correspondingly, the conductive members 3 embedded in each through-hole 101 are columnar or elongated. For a single grid line, it can simultaneously contact the independent contact portions 2 on the top of multiple columnar conductive members 3, or it can contact the elongated contact portion 2 on the top of a single elongated conductive member 3.

[0064] More specifically, the through hole 101 is an elongated through hole, the through member 3 is an elongated structure embedded in the through hole 101, and the contact portion 2 at the top of the through member 3 is elongated.

[0065] Alternatively, the through hole 101 is a columnar hole, and the contact portions 2 on two adjacent conductive members 3 are spaced apart. In this case, the contact portion 2 is preferably also columnar, and the shape of the conductive surface of the contact portion 2 used for contacting the grid line is not limited.

[0066] When the contact part 2 is elongated, the number of contact parts corresponding to the same grid line can be more than one.

[0067] The specific shape of the through hole 101, whether cylindrical or elongated, can be selected according to actual needs. The main advantages of multiple cylindrical holes are simple manufacturing, low processing cost, and saving on conductive material. As for the elongated through hole 101, both the final conductive element 3 and the contact portion 2 are elongated, allowing the elongated conductive element 3 to contact and conduct with the grid line, reducing contact loss and improving conductivity.

[0068] In addition, as a special configuration, when the through hole 101 is a plurality of columnar holes spaced apart, the contact portion 2 formed on the front side of the insulating substrate 1 can be connected as a strip to contact the strip-shaped main grid line or sub-grid line. Preferably, the extension direction of the contact portion 2 is parallel or perpendicular to the extension direction of the grid line on the battery cell.

[0069] Of course, in each embodiment, regardless of whether the contact portion 2 is columnar or elongated, whether its contact surface protrudes from the front side of the insulating substrate 1 can be optimized according to the actual situation, and will not be elaborated here.

[0070] The contact part 2 and the conductive part 3, except for the contact part 2, can be integrally formed or separately formed.

[0071] The electrical connection structure for back contact batteries in this invention can solve the electrical contact problem when the grid lines on the back of the back contact battery are connected by the common arrangement of multiple contact parts and conductive circuits on both the front and back sides of the insulating substrate. This ensures that the contact parts accurately contact the grid lines of the back contact battery, achieving a more efficient and reliable electrical connection. At the same time, it can also reduce the risk of short circuits.

[0072] More specifically, the aforementioned insulating substrate 1 is made of a high-temperature resistant material, which is further preferably any one of a glass plate, an FR-4 plate (glass fiber reinforced epoxy resin plate), a ceramic substrate, a CEM-3 plate (composite copper clad laminate), a polyimide plate, a PTFE plate (polytetrafluoroethylene plate), or a Rogers plate.

[0073] Preferably, the thickness of the insulating substrate 1 is 0.2 mm to 10 mm. In actual installation, the thickness of the insulating substrate 1 is preferably related to the material of the insulating substrate 1. For example, when the material of the insulating substrate 1 is glass, its thickness is preferably 0.2 mm to 1 mm; when the material of the insulating substrate 1 is FR-4, its thickness is preferably 0.5 mm to 10 mm.

[0074] More specifically, regarding the contact portion 2 in the preferred embodiment, it can be disposed flush with the front surface of the insulating substrate 1, or it can be disposed protruding from the front surface of the insulating substrate 1, such as... Figures 1-2As shown, the latter is as Figures 3-5 As shown in the image.

[0075] As follows, through Figures 1-5 Two configurations of the contact portion 2 in the preferred embodiment of this utility model will be described.

[0076] exist Figure 1 In the middle, the top of the contact portion 2 is flush with the front side of the insulating substrate 1.

[0077] exist Figure 2 In this case, the surface of the contact portion 2 is flush with the front side of the insulating substrate 1. At this time, it is equivalent to having an embedding hole 102 for embedding the contact portion 2 on the front side of the insulating substrate 1, and after the contact portion 2 is connected to the conductive member 3, it is embedded in the embedding hole 102.

[0078] exist Figure 3 In the middle, the top of the contact portion 2 protrudes from the front side of the insulating substrate 1.

[0079] exist Figure 4 In this configuration, the contact portion 2 protrudes entirely from the front surface of the insulating substrate 1 and is flush with the top of the conductive member 3 on the front surface of the insulating substrate 1. At this time, the width of the contact portion 2 may be equal to or not equal to the width of the conductive member 3; for example, in the figure, the width of the contact portion 2 is greater than the width of the conductive member 3.

[0080] exist Figure 5 In the middle, part of the contact portion 2 is embedded in the embedded hole 102 opened on the front side of the insulating substrate 1, and part of it protrudes from the front side of the insulating substrate 1.

[0081] More specifically, for the arrangement of the contact portion 2 protruding from the front side of the insulating substrate 1, the protrusion size of the contact portion 2 is preferably 5μm to 100μm. Within this range, the breakage rate of the battery cell and the contact conductivity quality when the contact portion 2 contacts the battery cell can be balanced, while saving the material of the contact portion 2.

[0082] More preferably, the portions of the insulating substrate 1 where the contact portions 2 are not provided are made hollow or made of transparent material. When some portions are hollowed out, on the one hand, the weight of the insulating substrate 1 can be reduced, improving the portability of the insulating substrate 1; on the other hand, the hollowed-out design also facilitates the observation of the alignment between the insulating substrate 1 and the battery cell when they are matched. Of course, the insulating substrate 1 can also be aligned between the contact portions 2 and the back contact battery by making some areas transparent.

[0083] Furthermore, by creating a perforation on the insulating substrate 1, an adsorption hole can be formed on the insulating substrate 1 through the perforation, and an adsorption channel communicating with the adsorption hole can be provided in the insulating substrate 1. This can improve the bonding quality between the electrical connection structure and the back contact battery by negative pressure adsorption when the contact part 2 comes into contact with the back of the back contact battery, improve the bonding degree between the contact part 2 and the grid line on the back of the battery, prevent fragmentation, and improve the conductivity of the electrical connection structure.

[0084] More specifically, the vias 101 on the insulating substrate 1 can be formed by laser or other perforation processing methods.

[0085] For contact portion 2, when contact portion 2 is formed separately from other parts of conductive member 3, one end of it is used to abut against the grid lines on the back of the battery, and the other end is used to connect to other parts of conductive member 3. The end of other parts of conductive member 3 away from contact portion 2 is connected to conductive circuit 4. Conductive member 3 enables the grid lines on the back of the battery to be connected to the conductive circuit 4 of the corresponding polarity, so as to complete tasks such as battery testing or laser-induced sintering processing.

[0086] As a feasible example, the width of the contact portion 2 is greater than the width of other parts of the conductor 3. This ensures the contact reliability of the contact portion 2 and the conduction function of the conductor 3, while also saving costs due to the smaller material required for the conductor 3. Furthermore, by setting the width of the contact portion 2 to be greater than the width of other parts of the conductor 3, the conducting cross-sectional area of ​​the contact portion 2 is greater than that of the conductor 3. This arrangement also helps prevent electrical overload during the use of the electrical connection structure.

[0087] It should be noted that the aforementioned "width" refers to the dimension in the width direction of each grid line on the back of the back contact battery when the insulating substrate 1 and the back contact battery are mated and abutted. It can be understood that when the cross-section of the contact portion 2 and the conductive member 3 is circular, the aforementioned "width" is actually the outer diameter of the contact portion 2 and the conductive member 3. In this case, the contact portion 2 and the conductive member 3 are preferably coaxially arranged.

[0088] In actual setup, the contact part 2 can be a plane or a curved surface for contacting the grid wires.

[0089] For example, in a preferred embodiment, to improve the conductivity of the electrical connection structure, each contact portion 2 is preferably provided with an arc-shaped groove on its contact surface, forming a concave arc-shaped conductive surface. The two ends of the arc-shaped groove extend through both sides of the outer periphery of the contact portion 2, and the axis of the arc-shaped surface is preferably parallel to the gate wire to be crimped. Simultaneously, the depth of the arc-shaped groove is not greater than the height of the contact portion 2 protruding from the front of the insulating substrate 1. By utilizing the concave arc-shaped surface, the contact area when the gate wire is crimped with the contact portion 2 can be effectively increased, thereby improving the conductivity between the contact portion 2 and the gate wire.

[0090] More preferably, depending on the size of the grid line of the contact portion 2, the width of the contact portion 2 is preferably between 10 μm and 500 μm.

[0091] In addition, in actual installation, the contact portion 2 can protrude entirely from the front surface of the insulating substrate 1 as needed, or it can be partially embedded in the front surface of the insulating substrate 1 as needed. In the latter case, part of the contact portion 2 is embedded in the insulating substrate 1, and the other part protrudes from the front surface of the insulating substrate 1. In this case, it is equivalent to the other parts of the conductive member 3 not completely filling the through hole 101.

[0092] In the case where the two contact portions are embedded in the through hole 101, such as Figure 2 As shown, an embedding hole 102 can be further formed on the front side of the insulating substrate 1 for each through hole 101, and one end of the contact portion 2 that connects to other parts of the conductive member 3 is embedded in the embedding hole 102.

[0093] To further improve the conductivity of the contact portion 2, in a preferred embodiment, the contact portion 2 further includes a metal protrusion 201 and a surface plating layer 202 disposed on the surface of the metal protrusion 201. The surface plating layer 202 is used to contact the battery cell grid lines. By providing the surface plating layer 202 on the metal protrusion 201, the contact performance between the contact portion 2 and the back contact battery can be increased.

[0094] More preferably, the material of the metal protrusion 201 is the same as that of the contact portion 2, and the two can be integrally formed or manufactured separately. Furthermore, the surface plating 202 disposed on the surface of the metal protrusion 201 is preferably a gold layer. The thickness of the surface plating 202 is 10 μm to 200 μm, which, within this range, can improve contact performance and save costs.

[0095] Furthermore, in actual installation, the material of the conductive element 3 (including the contact portion 2 and other parts of the non-contact portion 2 of the conductive element 3) is preferably any one of copper, aluminum, silver, gold, tungsten, titanium, and nickel, or an alloy of any one of these metals, such as copper alloys or aluminum alloys. The materials of the contact portion 2 and other parts of the conductive element 3 can be the same or different. It should be noted that when the conductive element 3 is made of an alloy, it must be an alloy material available from the prior art, and improvements to the alloy material are not the focus of this invention.

[0096] Furthermore, in the preferred embodiment, the electrical connection structure also includes an elastic device (not shown) located on the back side of the insulating substrate 1. This elastic device is connected to the back side of the insulating substrate 1. By providing the elastic device, a buffering effect can be achieved when the electrical connection structure abuts against the back grid lines of the battery cell, preventing the contact portion 2 from making hard contact with the back grid lines of the battery and preventing battery fragmentation. Preferably, the elastic device includes a mounting plate and elastic elements (e.g., springs) arranged in an array on the mounting plate. One end of the elastic element is connected to the mounting plate, and the other end is connected to or abuts against the back side of the insulating substrate 1.

[0097] Furthermore, the forming method of the conductive element 3 can be any one of screen printing, inkjet printing, or electroplating. The forming methods of the contact portion 2 and other parts of the conductive element 3 can be the same or different. Of course, the forming method of the conductive element 3 is not limited to the aforementioned methods; other methods that can achieve similar setting effects can also be used for its forming. For example, the conductive element 3 can be made of metal material into a columnar or elongated shape and then embedded in the through hole 101, for example, by inserting it into the through hole 101. In a preferred embodiment, when the contact portion 2 and other parts of the conductive element 3 are formed separately, the forming method of the other parts of the conductive element 3 is preferably obtained by filling the through hole 101 with nano-metal paste through screen printing or inkjet printing, or by electroplating or metal seed deposition. The forming method of the contact portion 2 is preferably to apply a mask to the surface of the insulating substrate 1 and then fabricate it by metal deposition or electroplating. In another embodiment, the contact portion 2 and the conductive element 3 are integrally formed, in which case the forming method of the contact portion 2 is preferably the same as the forming method of the conductive element 3.

[0098] More specifically, in order to improve the conductivity quality when the contact part 2 is crimped with a single grid line, in actual installation, for the conductivity of a single grid line, it is preferable to include multiple contact parts 2 connected to the same conduction circuit 4, and use multiple contact parts 2 to crimp different areas on the extension path of the single grid line, thereby ensuring the conductivity quality of the grid line and avoiding conductivity problems caused by local grid breakage.

[0099] Preferably, the through hole 101 is a columnar hole, and the contact portions 2 on two adjacent conductive members 3 are spaced apart; wherein, among the multiple contact portions 2 on the insulating substrate 1 used for contacting the same gate line, at least two contact portions 2 are offset along the extension direction perpendicular to the gate line, so as to better achieve the requirement of positioning and aligning the electrical contact structure with the gate line.

[0100] Furthermore, in the preferred embodiment, the conducting circuit 4 is used to connect multiple conductive elements 3 spaced apart to the same circuit, and to form at least one circuit on the back side of the insulating substrate 1 that can be connected to the positive terminal of an external power supply, and at least one circuit that can be connected to the negative terminal of an external power supply, thereby providing a conducting power supply of corresponding polarity to the contact portions 2 at different positions.

[0101] In specific selection, the conductive loop 4 is preferably a finished metal wire, such as a copper wire. Based on the division of the conductive area, all conductive elements corresponding to the same polarity grid line are connected to the same wire, and the wire is connected to the positive or negative terminal of an external power supply. In actual installation, it is preferable to connect multiple conductive elements 3 corresponding to the same grid line to the same wire branch (this wire branch is also preferably a copper wire), and then connect multiple wire branches to at least one main wire formed by copper wire. Furthermore, the connection between the wire branch and the conductive element, and between the wire branch and the main wire, can be further preferably welded, such as by laser spot welding.

[0102] Of course, in addition to using copper wires, other methods can be used to set up the conductive circuit 4 in the preferred embodiment. For example, it can be done by using nano-conductive ink / paste spraying, electroplating a metal layer, or welding the whole metal plate / sheet after patterning. As long as the function of conductive circuit 4 can be achieved, it is acceptable.

[0103] It is understood that for different back-contact batteries, the grid arrangement on the back of the battery is different. The number and arrangement of the contact portions 2 on the insulating substrate 1 in the aforementioned electrical connection structure of this application are different, and the arrangement of the conductive circuit 4 on the back of the insulating substrate 1 is also different.

[0104] For example, in a specific embodiment, the back contact battery is a gridless battery (OBB-BC). Multiple fine grids are arranged in parallel at intervals on the back side of the back contact battery. The grid lines corresponding to the P-region and the grid lines corresponding to the N-region are arranged parallel to each other and alternate sequentially. In this case, as one example, the contact portion 2 on the insulating substrate 1 in the electrical connection structure is a staggered array of columnar structures, with the arrangement on both the front and back sides as follows: Figure 6 , Figure 7 As shown, the conductive channels corresponding to the two polarity gate lines are staggered in the direction perpendicular to the extension of each fine gate (i.e., the vertical direction shown in the figure).

[0105] When the back contact battery is a gridless battery (OBB-BC), as another example, the contact portion 2 on the insulating substrate 1 in the electrical connection structure is a staggered strip structure (relative to multiple columnar through holes 101 corresponding to the same fine grid line being a single elongated through hole 101). In this case, the conductive element 3 embedded in the elongated through hole 101 is also elongated, and an elongated contact portion 2 is formed on the front side of the insulating substrate 1, so that the elongated contact portion 2 abuts against the elongated fine grid for conduction. Of course, the form in which the through hole 101 is opened can still be as follows... Figure 7 The columnar hole shown is replaced by a contact portion 2 on the front side of the insulating substrate 1, which is a long strip structure that simultaneously connects the ends of multiple conductive elements 3 (equivalent to...). Figure 6 The four horizontally spaced contact portions are replaced with horizontally extending strip-shaped structures, thereby allowing the strip-shaped contact portions 2 to abut and conduct with the fine grid lines on the back of the battery cell.

[0106] Preferably, for a gridless battery (OBB-BC), when the contact portion 2 is elongated, its extension direction is parallel to the sub-grid direction, contacting the sub-grid line.

[0107] In a specific embodiment two, the back contact battery is a battery with a main grid. In this case, as one example, the contact portions 2 on the insulating substrate 1 of the electrical connection structure are arranged in an array, and the arrangement of the front and back sides of the insulating substrate 1 is as follows. Figure 8 , Figure 9 As shown, the conductor 3 is correspondingly set at the main gate position, and the main gates of different polarities are electrically connected to external power supplies of different polarities through the conductor 3.

[0108] In a specific embodiment three, the back contact battery is another type of battery with a main grid. In this case, as another example, the contact portion 2 on the insulating substrate 1 of the electrical connection structure is arranged as follows: Figure 10 The diagram shows a columnar shape, and the conductive loop 4 on the back side of the insulating substrate 1 is arranged as follows: Figure 11 As shown, the conductor 3 is correspondingly disposed at the fine gate position, and the fine gates of different polarities are electrically connected to the power supply of different polarities through the conductor 3.

[0109] As another example, for a back-contact battery with main grid lines, the contact portion 2 and the conductive element 3 on the insulating substrate 1 can also be set for the main grid on the battery cell, so that the contact portion 2 abuts and conducts with the main grid on the battery cell; at this time, the contact portion 2 is a plurality of cylindrical contact portions 2 spaced apart in the main grid extension direction or a long strip contact portion 2 continuously extending in the main grid extension direction. The first electrical contact portion and the second electrical contact portion abut against the main grid of the two polarity grid lines on the battery cell respectively, so as to realize the conduction between the electrical connection structure and the two grid lines of the battery cell.

[0110] In addition, as another example, for a back contact battery with main grid lines, the insulating substrate 1 can also provide contact portions 2 for the main grid and fine grid of different polarities on the battery cell, so that when the insulating substrate 1 comes into contact with the battery cell, the grid lines of different polarities have contact portions 2 to abut and conduct; at this time, the contact portions 2 provided for the main grid and the sub-grid can be multiple cylindrical structures, or single or multiple strip structures.

[0111] In other words, for a back contact battery with a main grid, when the contact part 2 is elongated, its extension direction can be parallel to the sub-grid direction to contact the sub-grid line, parallel to the main grid direction to contact the main grid line, or a combination of both.

[0112] The electrical connection structure for back contact batteries in this invention can solve the electrical contact problem when the grid lines on the back of the back contact battery are connected by multiple contact parts and multiple conductive circuits on both the front and back sides of the insulating substrate. This ensures the conductivity and quality of the grid lines of the back contact battery, while avoiding battery fragmentation or microcracks caused by uneven pressure distribution. It also improves the convenience of back contact battery processing and testing, and reduces the processing and application costs of back contact batteries.

[0113] 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 connection structure for a back contact cell, characterized by, include: An insulating substrate, wherein a plurality of first and second through holes are spaced apart on the insulating substrate and penetrate its front and back sides, the positions of the first and second through holes corresponding to the positive grid line and the negative grid line of the back contact battery, respectively. The conductive element includes a plurality of first electrical conductive elements and a plurality of second electrical conductive elements, which are respectively embedded in the first conductive hole and the second conductive hole; The top of the conductive element is a contact portion, and each contact portion protrudes or is flush with the front side of the insulating substrate; the top of the first electrical conductive element is a first electrical contact portion, and the top of the second electrical conductive element is a second electrical contact portion. The first electrical contact portion and the second electrical contact portion are respectively used to contact the positive grid line and the negative grid line of the back contact battery. The conductive circuit, located on the back side of the insulating substrate, includes a first circuit and a second circuit that can be electrically connected to electrodes of different polarities of an external power source. The first circuit is connected to at least a portion of the first conductive element, and the second circuit is connected to at least a portion of the second conductive element.

2. The electrical connection structure for a back contact battery according to claim 1, characterized in that, The through hole is an elongated through hole, the conductive element is elongated, and the contact portion at the top of the conductive element is elongated; Alternatively, the through hole is a cylindrical hole, and the contact portions on two adjacent through members are spaced apart; Alternatively, the through hole is a columnar hole, with multiple through holes corresponding to the same grid line, and the contact portions on the multiple through holes corresponding to the same grid line are connected as a whole in an elongated shape.

3. The electrical connection structure for back contact cells according to claim 1, characterized in that, The contact portion is integrally formed with or separately formed from other parts of the conductive component.

4. The electrical connection structure for back contact cells according to claim 1, characterized in that, The insulating substrate is a glass plate, FR-4 plate, ceramic substrate, CEM-3 plate, polyimide plate, PTFE plate or Rogers plate; and / or The thickness of the insulating substrate is 0.2mm to 10mm; and / or The surface of the contact portion protrudes from the front side of the insulating substrate, and the protrusion height is 5μm~100μm.

5. The electrical connection structure for back contact cells according to claim 1, characterized in that, The portion of the insulating substrate without contact parts is either hollowed out or made of transparent material.

6. The electrical connection structure for back contact cells according to claim 1, characterized in that, The insulating substrate has adsorption holes at the parts without contact portions, and an adsorption channel communicating with the adsorption holes is provided inside the insulating substrate.

7. The electrical connection structure for back contact cells according to claim 1, characterized in that, The width of the contact portion is greater than the width of other parts of the conductive element; and / or The contact portion has a flat or curved surface for contacting the grid lines.

8. The electrical connection structure for back contact cells according to claim 1, characterized in that, The width of the contact portion is between 10μm and 500μm.

9. The electrical connection structure for back contact cells according to claim 1, characterized in that, The contact portion includes a metal protrusion and a surface coating disposed on the surface of the metal protrusion, the surface coating being used to contact the cell grid lines.

10. The electrical connection structure for back contact cells according to claim 9, characterized in that, The thickness of the surface coating is 10μm~200μm; And / or, the material of the surface coating is gold.

11. The electrical connection structure for a back contact battery according to any one of claims 1 to 10, characterized in that, The conductive component is made of any one of copper, aluminum, silver, gold, tungsten, titanium, or nickel, or an alloy thereof.

12. The electrical connection structure for a back contact battery according to claim 1, characterized in that, The conductive circuit is a wire, or the conductive circuit is made by printing nano-conductive ink, electroplating a metal layer, or patterning a whole metal plate.

13. The electrical connection structure for a back contact battery according to claim 1, characterized in that, The through hole is a columnar hole, and the contact portions on two adjacent through members are spaced apart; wherein, among the contact portions on the insulating substrate used to contact the same gate line, at least two contact portions are offset along the extension direction perpendicular to the gate line.

14. The electrical connection structure for a back contact battery according to claim 1, characterized in that, It also includes an elastic device connected to the back side of the insulating substrate for providing cushioning when the insulating substrate abuts against the grid lines on the battery cell with a contact portion.

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