Photovoltaic module hot spot protection diode

Abstract

The utility model discloses a hot spot protection diode for a photovoltaic module, which comprises a diode chip, a diode chip positive electrode lead, a diode chip negative electrode lead, a positive electrode metal shell, a negative electrode metal shell and a plastic package body, the positive electrode pin of the diode chip is connected with one end of the diode chip positive electrode lead, and the negative electrode pin of the diode chip is connected with the other end of the diode chip negative electrode lead. The other end of the anode lead of the diode chip is connected with the interior of the anode metal shell, the cathode pin of the diode chip is connected with one end of the cathode lead of the diode chip, and the other end of the cathode lead of the diode chip is connected with the interior of the cathode metal shell. The diode chip, the diode chip anode lead and the diode chip cathode lead are all fixed in the plastic package body, and two ends of the plastic package body are respectively contacted and fixed with the interiors of the anode metal shell and the cathode metal shell. According to the utility model, the reliable contact between the hot spot protection diode of the photovoltaic module and the metal base is realized, and the installation and replacement of the hot spot protection diode of the photovoltaic module are facilitated.

Description

Technical Field

[0001] This utility model relates to the field of diode technology, and in particular to a photovoltaic module hot spot protection diode. Background Technology

[0002] In recent years, global photovoltaic (PV) installations have grown rapidly. PV modules are the core component of PV power plants. The core of a PV module is a string of PV cells connected in series and parallel. A PV cell string is formed by multiple PV cells connected in series. A hotspot protection diode is connected in parallel across the PV cell string. When the PV module is operating normally, the hotspot protection diode is reverse-biased and does not conduct. When some PV cells in the PV module are shaded, forming hotspots, the hotspot protection diode is forward-biased and conducts. After the hotspot protection diode is forward-biased and conducts, the current in the PV module is discharged through the diode's circuit, preventing further heating and damage to the PV cell string containing the shaded PV cells.

[0003] Common diode packaging structures include axial, surface-mount, and modular structures. These types of diodes are widely used in electronic circuit boards. Currently, the photovoltaic module hot spot protection diodes used in the photovoltaic industry adopt the diode structure used in the electronics industry, that is, the aforementioned conventional diode packaging structures.

[0004] Applying diode structures from the electronics industry to hot spot protection in photovoltaic (PV) modules only allows for two methods: snap-fit ​​and soldering. Snap-fit ​​uses the elasticity of metal to secure the diode leads to the PV junction box. However, because the diode leads used in the electronics industry are small, the snap-fit ​​method results in unreliable contact between the diode leads and the base due to the small contact area. With PV modules having a lifespan of up to 30 years, this snap-fit ​​method frequently causes the PV junction box to overheat and fail. To address this issue, some companies solder the hot spot protection diodes in the PV module junction box to the junction box base. However, soldering makes replacing damaged hot spot protection diodes extremely inconvenient. Especially now, to ensure the airtightness of PV junction boxes, they are typically sealed with potting compound. Furthermore, modern PV modules weigh over 30 kilograms, have an area of ​​nearly 3 square meters, and can be installed at heights exceeding 3 meters. When the hot spot protection diode fails, the PV module must be manually removed from the PV support, the junction box disassembled, and the potting compound destroyed to locate the failed hot spot protection diode. Since there was no suitable AC power supply on site, the photovoltaic modules had to be moved to a location with AC power first. Then, the failed hotspot protection diodes were removed using a soldering iron, or the photovoltaic modules were directly transported to the manufacturer for replacement of the failed hotspot protection diodes and junction boxes. This process was not only time-consuming and labor-intensive, but it could also damage the modules, and the entire process required a significant amount of labor and time costs. Utility Model Content

[0005] To address the problem of inconvenient replacement of hot spot protection diodes in existing technologies, this invention proposes a diode structure specifically for hot spot protection of photovoltaic modules. This structure enables the photovoltaic module hot spot protection diode to reliably contact its base without welding, and also allows for easy disassembly and replacement of failed photovoltaic module hot spot protection diodes at the photovoltaic power station site.

[0006] The technical solution adopted in this utility model is as follows:

[0007] A photovoltaic module hot spot protection diode includes a diode chip, a positive lead of the diode chip, a negative lead of the diode chip, a positive metal casing, a negative metal casing, and a molding compound. The positive lead of the diode chip is connected to one end of the positive lead of the diode chip, and the other end of the positive lead of the diode chip is connected to the inside of the positive metal casing. The negative lead of the diode chip is connected to one end of the negative lead of the diode chip, and the other end of the negative lead of the diode chip is connected to the inside of the negative metal casing. The diode chip, the positive lead of the diode chip, and the negative lead of the diode chip are all fixed inside the molding compound. The two ends of the molding compound are respectively connected to the inside of the positive metal casing and the inside of the negative metal casing.

[0008] Furthermore, the positive electrode metal casing is a columnar metal casing.

[0009] Furthermore, the cross-sectional shape of the positive electrode metal shell is any one or more combinations of circular, triangular, quadrilateral, pentagonal, and hexagonal shapes.

[0010] Furthermore, the positive electrode metal casing has a boss on its exterior.

[0011] Furthermore, the interior of the positive electrode metal casing is connected to the positive electrode lead of the diode chip via solder paste.

[0012] Furthermore, the negative electrode metal shell is a columnar metal shell.

[0013] Furthermore, the cross-sectional shape of the negative electrode metal shell is any one or more combinations of circular, triangular, quadrilateral, pentagonal and hexagonal shapes.

[0014] Furthermore, the interior of the negative electrode metal casing is connected to the negative electrode lead of the diode chip via solder paste.

[0015] Furthermore, the encapsulated body is a cylindrical encapsulated body.

[0016] Furthermore, the cross-sectional shape of the molding compound is any one or more combinations of a circle, triangle, quadrilateral, pentagon, and hexagon.

[0017] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0018] This invention improves the structure of the positive and negative leads of the photovoltaic module hot spot protection diode chip by welding the positive and negative leads to the positive and negative metal casings. This significantly increases the surface area of ​​the positive and negative metal electrodes of the photovoltaic module hot spot protection diode, allowing for reliable contact between the diode and its base via a snap-fit ​​connection, thus avoiding welding. The improved photovoltaic module hot spot protection diode encapsulates and fixes its diode chip and positive and negative leads inside the metal casing, resulting in more reliable encapsulation, unlike current structures that only encapsulate the hot spot protection diode chip.

[0019] The above description is only an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, the preferred embodiments of this utility model are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the positive electrode structure of this utility model;

[0021] Figure 2 This is a schematic diagram of the negative electrode structure of this utility model;

[0022] Figure 3 This is a schematic diagram of the overall structure of this utility model;

[0023] Explanation of reference numerals in the attached diagram: 1-1, Positive metal casing; 1-2, Negative metal casing; 2-1, Positive lead of diode chip; 2-2, Negative lead of diode chip; 3, Solder paste; 4, Molded enclosure; 5, Diode chip. Detailed Implementation

[0024] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.

[0025] like Figure 1 As shown, a photovoltaic module hot spot protection diode includes a positive electrode structure and a negative electrode structure. The positive electrode structure includes a positive electrode metal shell 1-1, a diode chip positive electrode lead 2-1, and solder paste 3. The interior of the positive electrode metal shell 1-1 is connected to one end of the diode chip positive electrode lead 2-1 through the solder paste 3.

[0026] like Figure 2As shown, the negative electrode structure includes a negative electrode metal shell 1-2, a diode chip negative electrode lead 2-2, and solder paste 3. The interior of the negative electrode metal shell 1-2 is connected to one end of the diode chip negative electrode lead 2-2 through the solder paste 3.

[0027] like Figure 3 As shown, a photovoltaic module hot spot protection diode also includes a diode chip 5 and a molding compound 4. The positive terminal of the diode chip 5 is connected to the other end of the positive lead 2-1 of the diode chip, and the negative terminal of the diode chip 5 is connected to the other end of the negative lead 2-2 of the diode chip. The diode chip 5, the positive lead 2-1 of the diode chip, and the negative lead 2-2 of the diode chip are all fixed inside the molding compound 4. The two outer ends of the molding compound 4 are in contact with and fixed to the interior of the positive metal shell 1-1 and the negative metal shell 1-2, respectively.

[0028] Among them, diode chip 5 includes, but is not limited to, Schottky diodes.

[0029] This utility model does not specifically limit the materials and shapes of the positive lead 2-1 and the negative lead 2-2 of the diode chip. For example, the material can be copper plated with tin, copper plated with nickel, iron-nickel alloy, gold or silver; the shape can be wire or sheet.

[0030] This invention does not impose specific limitations on the connection method between the positive and negative leads of diode chip 5 and the positive lead 2-1 and negative lead 2-2 of diode chip 5. For example, the connection method can be through solder paste or conductive adhesive.

[0031] The positive electrode metal casing 1-1 is a columnar metal casing made of one or more of copper plated with tin, copper plated with nickel, or iron-nickel alloy.

[0032] The cross-sectional shape of the positive electrode metal casing 1-1 is any one or more combinations of circular, triangular, quadrilateral, pentagonal and hexagonal shapes.

[0033] When the cross-sectional shape of the positive electrode metal casing 1-1 is set to be circular, the diameter is 2-20mm; when the cross-sectional shape of the positive electrode metal casing is set to be equilateral triangle, the side length is 2-20mm. If the size is too small, the contact will be poor. This size can also match the current junction box size; when the cross-sectional shape of the positive electrode metal casing is set to be square, the side length is 2-20mm; when the cross-sectional shape of the positive electrode metal casing is set to be regular pentagon, the side length is 2-20mm; when the cross-sectional shape of the positive electrode metal casing is set to be regular hexagon, the side length is 2-20mm.

[0034] The axial length of the positive electrode metal casing 1-1 is 2-20mm.

[0035] The wall thickness of the positive electrode metal casing 1-1 is 0.1-2mm.

[0036] The positive metal casing 1-1 has a protrusion on its exterior. The end with the protrusion is the positive terminal of the photovoltaic module hot spot protection diode, which can be easily distinguished from the negative terminal. When replacing it at high altitude, the positive and negative terminals can be quickly and easily identified by touch.

[0037] The negative electrode metal casing 1-2 is a columnar metal casing made of one or more of copper-plated tin, copper-plated nickel, or iron-nickel alloy.

[0038] The cross-sectional shape of the negative electrode metal casing 1-2 can be any combination of one or more of the following: circular, triangular, quadrilateral, pentagonal, and hexagonal. When the cross-sectional shape of the negative electrode metal casing 1-2 is circular, the diameter is 2-20 mm; when the cross-sectional shape of the negative electrode metal casing 1-2 is equilateral triangular, the side length is 2-20 mm; when the cross-sectional shape of the negative electrode metal casing 1-2 is square, the side length is 2-20 mm; when the cross-sectional shape of the negative electrode metal casing 1-2 is regular pentagonal, the side length is 2-20 mm; and when the cross-sectional shape of the negative electrode metal casing 1-2 is regular hexagonal, the side length is 2-20 mm.

[0039] The axial length of the negative electrode metal casing 1-2 is 2-20mm.

[0040] The wall thickness of the negative electrode metal casing 1-2 is 0.1-2mm.

[0041] The encapsulation body 4 is a columnar encapsulation body made of any one or more of epoxy resin, polybutylene terephthalate, polyphthalamide, polyimide, silicone resin, or ceramic.

[0042] The cross-sectional shape of the molding compound 4 is any combination of one or more of the following: circular, triangular, quadrilateral, pentagonal, and hexagonal.

[0043] When the cross-sectional shape of the encapsulant 4 is set to a circle, the diameter is 2-20mm; when the cross-sectional shape of the encapsulant 4 is set to an equilateral triangle, the side length is 2-20mm; when the cross-sectional shape of the encapsulant 4 is set to a square, the side length is 2-20mm; when the cross-sectional shape of the encapsulant 4 is set to a regular pentagon, the side length is 2-20mm; when the cross-sectional shape of the encapsulant 4 is set to a regular hexagon, the side length is 2-20mm.

[0044] The axial length of the encapsulated body 4 is 6-50mm.

[0045] The photovoltaic module hot spot protection diode in this invention can be applied to split-type photovoltaic junction boxes or integrated photovoltaic junction boxes.

[0046] The photovoltaic module hot spot protection diode of this utility model can be formed through the following steps:

[0047] 1) Lead wire filling: Connect one end of the positive lead 2-1 and the negative lead 2-2 of the diode chip to the positive and negative pins of the diode chip 5, respectively;

[0048] 2) Metal casing filling: Connect the other ends of the positive lead 2-1 and the negative lead 2-2 of the diode chip to the inside of the positive metal casing 1-1 and the negative metal casing 1-2, respectively;

[0049] 3) Mold closing: Place the filled diode chip positive lead 2-1, diode chip negative lead 2-2, diode chip 5, positive metal shell 1-1, and negative metal shell 1-2 into the packaging mold and close the mold.

[0050] 4) Molding: Molding material is injected into the packaging mold to form a molded body 4;

[0051] 5) Curing: Curing the finished product after plastic packaging.

[0052] When connecting the diode of this invention to a photovoltaic module, the diode can reliably contact a base with a suitable shape through a snap-fit ​​mechanism.

[0053] This invention, through the design of the encapsulation structure of the photovoltaic module hot spot protection diode, greatly increases the cross-sectional area of ​​the diode electrode, enabling reliable contact between the photovoltaic module hot spot protection diode and its base without soldering, and making the replacement of a failed photovoltaic module hot spot protection diode as convenient as replacing a fuse.

[0054] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A photovoltaic module hot spot protection diode, characterized in that, The diode chip (5), the diode chip positive lead (2-1), the diode chip negative lead (2-2), the positive metal shell (1-1), the negative metal shell (1-2) and the plastic package (4) are included, the positive pin of the diode chip (5) is connected with one end of the diode chip positive lead (2-1), the other end of the diode chip positive lead (2-1) is connected with the inside of the positive metal shell (1-1), the negative pin of the diode chip (5) is connected with one end of the diode chip negative lead (2-2), the other end of the diode chip negative lead (2-2) is connected with the inside of the negative metal shell (1-2), the diode chip (5), the diode chip positive lead (2-1) and the diode chip negative lead (2-2) are fixed in the inside of the plastic package (4), and the two ends of the plastic package (4) are connected with the inside of the positive metal shell (1-1) and the negative metal shell (1-2) respectively.

2. The photovoltaic module hot spot protection diode of claim 1, wherein, The positive metal shell (1-1) is a columnar metal shell.

3. The photovoltaic module hot spot protection diode of claim 1, wherein, The cross-sectional shape of the positive metal shell (1-1) is any one or a combination of more than one of a circular shape, a triangular shape, a quadrilateral shape, a pentagonal shape and a hexagonal shape.

4. The photovoltaic module hot spot protection diode of claim 1, wherein, The positive metal shell (1-1) is provided with a boss outside.

5. The photovoltaic module hot spot protection diode of claim 1, wherein, The inside of the positive metal shell (1-1) is connected with the diode chip positive lead (2-1) through the tin paste (3).

6. The photovoltaic module hot spot protection diode of claim 1, wherein, The negative metal shell (1-2) is a columnar metal shell.

7. The photovoltaic module hot spot protection diode of claim 1, wherein, The cross-sectional shape of the negative metal shell (1-2) is any one or a combination of more than one of a circular shape, a triangular shape, a quadrilateral shape, a pentagonal shape and a hexagonal shape.

8. The photovoltaic module hot spot protection diode of claim 1, wherein, The inside of the negative metal shell (1-2) is connected with the diode chip negative lead (2-2) through the tin paste (3).

9. The photovoltaic module hot spot protection diode of claim 1, wherein, The plastic package (4) is a columnar package.

10. The photovoltaic module hot spot protection diode of claim 1, wherein, The cross-sectional shape of the plastic package (4) is any one or a combination of more than one of a circular shape, a triangular shape, a quadrilateral shape, a pentagonal shape and a hexagonal shape.

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