A photovoltaic bypass diode module unit and its processing technology

Abstract

A photovoltaic bypass diode module unit and its processing technology. It relates to the field of semiconductor chip packaging technology, and in particular to improvements in the structure and processing technology of optical module type photovoltaic diodes. It provides a photovoltaic bypass diode module unit with clear polarity, easy identification, and good heat dissipation performance and its processing technology. It includes a frame one, a frame two, a chip, a jumper and a package body, the chip is fixedly welded on the frame two, the jumper connects the chip to the frame one to form a diode unidirectional conduction circuit, the package body seals the chip and the jumper, the package body is in a U or C shape, and the opening direction of the U or C shaped package body is toward the frame one. The product of the present invention is provided with a heat dissipation metal sheet (heat sink), which improves the heat dissipation effect and current carrying capacity.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor chip packaging, and in particular to improvements in the structure and processing technology of an optical module type photovoltaic diode. Background Art

[0002] During the use of solar cell modules, some parts may be shielded, which then consumes energy and generates heat as a load. This is the hot spot effect, which has a serious destructive effect on the module. Connecting a bypass diode in parallel at both ends of the solar cell module can effectively prevent the hot spot effect from damaging the battery module. With the development of technologies such as large silicon wafers and double-sided double-glass in the photovoltaic module industry, the power of the module continues to increase, and higher requirements are placed on the current carrying capacity of the diode. Under high current, in order to make the bypass diode work normally without being burned, on the one hand, the internal resistance of the chip should be reduced or multiple chips should be used, and on the other hand, the heat dissipation capacity of the package should be improved.

[0003] In order to avoid damage to diodes caused by lightning surges, the prior art (such as the photovoltaic power generation component bypass protection module 201620644097.4 of the present applicant) adopts a block circuit bypass structure for a group of solar cell components. Once a problem occurs in one of the chips, the entire module will fail.

[0004] To this end, CN110061695A, 2019-7-26, proposed a module for a solar cell junction box, which essentially encapsulates a diode chip to meet the needs of photovoltaic power generation.

[0005] However, the photovoltaic power generation industry still faces two realistic problems that need to be solved. First, my country has a vast territory. Even in a certain place on the same day, there will be huge differences in sunshine conditions, which places high demands on the overall heat dissipation performance of the module. Second, when assembling a large number of photovoltaic power generation components, the polarity identification of photovoltaic bypass diode modules must be solved. Summary of the invention

[0006] In view of the above problems, the present invention provides a photovoltaic bypass diode module unit with clear polarity, easy identification and good heat dissipation performance and a processing technology thereof.

[0007] The technical solution of the present invention is: it includes frame one, frame two, chip, jumper and package body, the chip is fixedly welded on frame two, the jumper connects the chip with frame one to form a one-way diode conduction circuit, the package body seals the chip and the jumper, the package body is in a U or C shape, and the opening direction of the U or C shaped package body is toward frame one.

[0008] A notch is provided in the frame 1 in the direction toward the package body, and a protrusion is provided in the frame 2 in the direction toward the package body. The protrusions extend into the notch and retain insulating gaps between them. The chip is fixedly arranged on the protrusions.

[0009] The frame 2 is provided with a busbar hole groove, and the busbar hole groove is located outside the packaging body.

[0010] A portion of the notch is located inside the package body, and another portion of the notch is located outside the package body.

[0011] It also includes a heat sink, which is in contact with the bottom surfaces of the first frame and the second frame, and an insulating oxide layer is provided on the surface of the heat sink; the bottom surface of the heat sink is at the same height as the bottom surface of the packaging body.

[0012] The heat sink is provided with convex columns at two corners facing the frame 1.

[0013] The bottom surface of the heat sink is provided with a removable protective film.

[0014] A concave groove is formed on the bottom surface of the heat sink.

[0015] A method for processing a photovoltaic bypass diode module unit, comprising the following steps:

[0016] 1) Stamping frame 1 and frame 2,

[0017] 2) Place the frame 1 and frame 2 into the welding device, then place the chip and jumper wire, and weld them;

[0018] 3) Attach a removable protective film to the bottom surface of the heat sink having a surface insulating oxide layer, and place the removable protective film downward into the packaging mold, place the welding assembly obtained in step 2) on the heat sink, and keep the top surface of the heat sink tightly fitted with the frame 1 and the frame 2; packaging;

[0019] 4) After packaging, remove the removable protective film.

[0020] On the basis of ensuring the performance of the product, the present invention sets the package body in a U or C shape, so that the operator can easily identify the polarity direction of the product during the assembly process, avoiding the need to carefully observe and identify the polarity of the product during busy work. In addition, in order to adapt to extreme climates, the product of the present invention is provided with a heat dissipation metal sheet (heat sink), which improves the heat dissipation effect and current carrying capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a three-dimensional schematic diagram of the present invention,

[0022] Figure 2It is a structural schematic diagram of the present invention,

[0023] Figure 3 It is a schematic diagram of the structure of the frame 1 in the present invention,

[0024] Figure 4 It is a structural schematic diagram of the frame 2 in the present invention,

[0025] Figure 5 is a schematic diagram of the structure of the heat sink in the present invention,

[0026] Figure 6 yes Figure 5 Middle AA section view,

[0027] Figure 7 is a schematic diagram of the internal structure of the module unit in the present invention,

[0028] Figure 8 yes Figure 7 Bottom view of

[0029] Fig. 9 is a schematic diagram of the structure of the encapsulated module unit in the present invention,

[0030] Fig.10 yes Fig. 9 Bottom view of .

[0031] In the figure, 1 is frame one, 11 is a notch, 2 is frame two, 21 is a protrusion, 22 is a busbar slot, 3 is a chip, 4 is a jumper, 5 is a package body, 6 is a heat sink body, 61 is a protrusion, 62 is an insulating oxide layer, 63 is a dent, and 7 is a removable protective film. DETAILED DESCRIPTION

[0032] The following is combined with Figure 1-10 Further explanation of the present invention: it includes frame 1, frame 2, chip 3, jumper 4 and package 5, chip 3 is fixedly welded on frame 2, jumper 4 connects chip 3 with frame 1 to form a diode unidirectional conduction circuit, package 5 seals chip 3 and jumper 4, package 5 is in U or C shape, and the opening direction of the U or C shape package faces frame 1. Of course, the polarity description of this patented product can be set according to the specific requirements of customers, and will not be repeated in this case.

[0033] A notch 11 is provided in the frame 1 towards the package body 5 , and a protrusion 21 is provided in the frame 2 towards the package body 5 . The protrusion 11 extends into the notch 21 and retains an insulating gap therebetween. The chip 3 is fixedly disposed on the protrusion 21 .

[0034] The frame 2 is provided with a busbar slot 22 , which is located outside the packaging body 5 .

[0035] Part of the notch 11 is located inside the package body 5, and the other part is located outside the package body 5. The part of the notch 11 located outside the package body 5 can be used as a busbar on one side of the connection frame 1.

[0036] It also includes a heat sink 6, which contacts the bottom surfaces of the frame 1 and the frame 2 1, and an insulating oxide layer 62 is provided on the surface of the heat sink 6; the bottom surface of the heat sink 6 is at the same height as the bottom surface of the package body 5. The heat sink 6 can be made of a material with good thermal conductivity such as aluminum alloy, and the insulating oxide layer 62 can be made of a dense metal oxide such as aluminum oxide, which has good corrosion resistance and good heat transfer.

[0037] The thermal conductivity of metal is much greater than that of plastic encapsulation material, so using metal heat sink to replace part of plastic encapsulation material for heat conduction can greatly improve the heat dissipation capacity of the package. The surface of the heat sink metal sheet is insulated and its shape is cylindrical. The thickness is the distance from the lower surface of the frame to the lower surface of the plastic encapsulation body. The cylindrical shape is consistent with the shape of the lower surface of the plastic encapsulation body. Its size is the size when all edges are 0.5mm away from each edge of the lower surface of the plastic encapsulation body. The 0.5mm margin ensures the bonding of the heat sink in the plastic encapsulation body and the strength of the plastic encapsulation body, avoiding the problem of the heat sink falling off or the plastic encapsulation body being easily damaged. This is a heat dissipation design that tends to the limit. In addition, considering the processing difficulty and cost of irregular metal sheets, the heat sink can also be designed to be a regular shape, and the size can be correspondingly reduced, but the heat dissipation capacity will be reduced to a certain extent.

[0038] The heat sink 6 is provided with protruding columns 61 at two corners facing the frame 1. The protruding columns 61 and the two corners of the frame 1 can be overlapped and packaged together, which can improve the structural strength of the package.

[0039] The bottom surface of the heat sink 6 is provided with a removable protective film 7 .

[0040] A notch 63 is provided on the bottom surface of the heat sink 6. The notch 63 facilitates quick finding of the overlap between the removable protective film 7 and the heat sink 6, so as to facilitate tearing off the protective film 7.

[0041] The processing method of the present invention is processed according to the following steps:

[0042] 1) Stamping frame 1 and frame 2,

[0043] 2) Place frame one 1 and frame two 2 into the welding device, then place the chip 3 and jumper wire 4, and weld them;

[0044] 3) Attach a removable protective film 7 to the bottom surface of the heat sink 6 having a surface insulating oxide layer, and place the removable protective film 7 into the packaging mold with the face downward, place the welding assembly obtained in step 2) on the heat sink 6, and keep the top surface of the heat sink 6 in close contact with the frame 1 and the frame 2; packaging;

[0045] 4) After packaging, remove the removable protective film 7.

[0046] The specific operation process is as follows: a sticky film (removable protective film 7) that can withstand high temperatures (the temperature range needs to be specified) is attached to the lower surface of the heat sink 6. A specific jig is used to place the corresponding number of heat sinks 6 into the cavity of the plastic encapsulation mold, and then the welded parts are placed for plastic encapsulation. Because the lower surface of the metal sheet is flush with the lower surface of the plastic encapsulation body, residual glue may remain after the plastic encapsulation is completed. At this time, the film (removable protective film 7) can be torn off to remove the residual glue and expose the surface of the metal sheet.

[0047] The present invention is not limited to the above-mentioned embodiments. On the basis of the technical solution disclosed in the present invention, technicians in this field can make some substitutions and deformations to some technical features therein according to the disclosed technical content without creative labor, and these substitutions and deformations are all within the protection scope of the present invention.

Claims

1. A photovoltaic bypass diode module unit, comprising a frame 1, a frame 2, a chip, a jumper and a package, wherein the chip is fixedly welded on the frame 2, the jumper connects the chip to the frame 1 to form a diode unidirectional conduction circuit, and the package seals the chip and the jumper, characterized in that: The package body is in a U or C shape, and the opening direction of the U or C-shaped package body faces the frame 1; It also includes a heat sink, which is in contact with the bottom surfaces of the first frame and the second frame, and an insulating oxide layer is provided on the surface of the heat sink; the bottom surface of the heat sink is at the same height as the bottom surface of the packaging body; the shape of the heat sink is cylindrical, the thickness is the distance from the lower surface of the frame to the lower surface of the plastic packaging body, and the shape of the cylinder is consistent with the shape of the lower surface of the plastic packaging body; The heat sink is provided with convex columns at two corners facing the frame 1 respectively; the convex columns and the two corners of the frame 1 are overlapped and packaged together.

2. A photovoltaic bypass diode module unit according to claim 1, characterized in that: A notch is provided in the frame 1 in the direction toward the package body, and a protrusion is provided in the frame 2 in the direction toward the package body. The protrusions extend into the notch and retain insulating gaps between them. The chip is fixedly arranged on the protrusions.

3. A photovoltaic bypass diode module unit according to claim 1, characterized in that: The frame 2 is provided with a busbar hole groove, and the busbar hole groove is located outside the packaging body.

4. A photovoltaic bypass diode module unit according to claim 2, characterized in that: A portion of the notch is located inside the package body, and another portion is located outside the package body.

5. A photovoltaic bypass diode module unit according to claim 1, characterized in that: The bottom surface of the heat sink is provided with a removable protective film.

6. A photovoltaic bypass diode module unit according to claim 1, characterized in that: A concave groove is formed on the bottom surface of the heat sink.

7. A method for processing a photovoltaic bypass diode module unit according to claim 1, characterized in that: Processing is as follows: 1) Stamping frame 1 and frame 2, 2) Place the frame 1 and frame 2 into the welding device, then place the chip and jumper wire, and weld them; 3) Attach a removable protective film to the bottom surface of the heat sink having a surface insulating oxide layer, and place the removable protective film downward into the packaging mold, place the welding assembly obtained in step 2) on the heat sink, and keep the top surface of the heat sink tightly fitted with the frame 1 and the frame 2; packaging; 4) After packaging, remove the removable protective film.

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