Patent Description:
With the gradual depletion of non-renewable energy such as fossil fuels, photovoltaic power generation, as way for green and renewable energy production, has attracted more and more attention and development.

Photovoltaic power generation involves converting energy from the sun into electricity using photovoltaic modules. One of a few key materials used in the photovoltaic module is an adhesive film. The adhesive film can be used as an internal packaging material of the photovoltaic module, such as crystalline silicon cells, thin film cells, double glass modules, and double-sided cells, and thus plays a key role in the packaging and protection of the photovoltaic module.

The photovoltaic module in related technologies includes a back plate, an adhesive film, solar cells, an adhesive film, and a front plate that are sequentially stacked. Generally, a sum of an area of each of the solar cells is smaller than an area of each adhesive film, and the two layers of adhesive film are separated at the periphery of corresponding solar cells. During laminating, it is easy to cause damage at the periphery of the corresponding solar cells, resulting in edge fragments and thus making the PV module unusable, thereby reducing the yield of the photovoltaic modules.

Therefore, how to provide an adhesive layer, a method for manufacturing the adhesive layer, and a photovoltaic module is a technical problem to be solved.

<CIT> discloses a solar cell panel. The solar cell panel disclosed therein includes a solar cell; a sealing member including a first sealing member disposed on a first surface of the solar cell and a second sealing member disposed on a second surface of the solar cell; a first cover member disposed on the first sealing member and including a glass substrate; and a second cover member disposed on the second sealing member and including a glass substrate, in which the sealing member includes a central region and an outer region positioned outside the central region, and the outer region includes a reinforcing region having a thickness greater than a thickness of the central region.

Chinese patent application <CIT> discloses a packaging adhesive film for a photovoltaic module. The packaging adhesive film includes a central area and an edge area which surrounds the central area and is connected with the central area, wherein the thickness of the edge area is greater than that of the central area; the width of the edge area is larger than or equal to the distance from the solder strip at the outermost side of the cell array of the photovoltaic module to the edge of the photovoltaic module, and the thickness of the edge area is <NUM>-<NUM>% larger than that of the central area.

Chinese patent application <CIT> discloses an adhesive packaging film material. The adhesive packaging film material includes a packaging material and a packaging material surrounding the packaging material, wherein the packaging material is fused with the edge of the packaging material.

Korean patent application <CIT> discloses a coater for hot melt to form an anti-sliding layer or an adhesive layer on the surface of raw cloth such as a mat without winding the raw cloth to a main roller. A coater for hot melt injects hot melt between a main roller and an auxiliary roller installed at a main body through the nozzle of a supply hose connected with a tank so as to allow the injected hot melt to be coated on the raw cloth on a belt conveyer by the main roller, wherein the main roller is filled with a heat transfer medium and is provided with an electric heater for maintaining the melting temperature of the hot melt to be constant, the rotation velocity of the main roller is larger than the transfer velocity of the belt conveyer for preventing the winding of the raw cloth transferred through the belt conveyer to the main roller, and a continuous transfer part is installed at the main body for the continuous coating of the hot melt.

Chinese patent application <CIT> discloses a solar cell module in which solar cells are wrapped between two adhesive films comprising encapsulating materials and sealing materials.

<CIT> discloses a solar cell module comprising: a front substrate; a rear substrate; solar cells disposed between the front substrate and the rear substrate; a barrier layer disposed at least one of between an outer portion of the front substrate and at least one of the solar cells, between the outer portion of the front substrate and the rear substrate, and between the at least one of the solar cells and the rear electrode; and a sealant, at least a part of which is disposed between the rear substrate and the at least one of the solar cells to the inside of the barrier layer in the solar cell module.

US patent application <CIT>discloses a photovoltaic module may include a rigid transparent upper layer followed by a pottant layer and a plurality of solar cells. Below the layer of solar cells, there is another pottant layer of similar material to that found in pottant layer. The solar cell may be recessed so that moisture barrier material may be applied along a substantial length of the edge of the module.

The invention is as set out in claim <NUM>. The preferred embodiments are set out in the appended set of dependent claims.

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the disclosure and together with the description thereof, are intended for explaining the principles of the disclosure.

The reference numerals in the figures are illustrated as follows: <NUM>-first portion, <NUM>-second portion, <NUM>-first sub-portion, <NUM>-second sub-portion, <NUM>-base plate, <NUM>-first edge, <NUM>-roller, <NUM>-axis, <NUM>-discharge device, <NUM>-first discharge device, <NUM>-second discharge device, <NUM>-first roller, <NUM>-second roller, <NUM>-third roller, <NUM>-first adhesive layer, <NUM>-second adhesive layer, <NUM>-solar cell, <NUM>-first glass cover plate, <NUM>-second glass cover plate, <NUM>-adhesive layer, <NUM>-photovoltaic module, X-thickness direction, Y-second direction, and Z-third direction.

Various exemplary embodiments of the disclosure will now be described in detail with reference to the accompanying drawings. It is to be noted that the relative arrangements of components, and the relative order of steps, numeric expressions, and values set forth in these embodiments do not limit the scope of the disclosure unless otherwise specified.

The following description of at least one exemplary embodiment is illustrative only and is not intended to limit the disclosure and application or use of the disclosure.

Techniques, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be regarded as part of the specification.

In all examples shown and discussed herein, any specific value should be interpreted as illustrative only and not as a limitation. Therefore, other examples of exemplary embodiments may have different values.

It is to be noted that like numerals and letters denote like terms in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

<FIG> is a structural schematic view illustrating an adhesive layer according to embodiments of the disclosure, which is a specific embodiment of the adhesive layer <NUM> provided in the disclosure. As shown in <FIG>, the adhesive layer <NUM> has a central region C1 and an edge region C2 at least partially surrounding the central region C1.

The adhesive layer <NUM> includes a first portion <NUM> and a plurality of second portions <NUM>. The first portion <NUM> includes a first material, and each second portion <NUM> includes a second material. The first portion <NUM> is located in the central region C1, and each of the plurality of second portions <NUM> is at least partially located in the edge region C2. In a thickness direction X, the first portion <NUM> and each of the plurality of second portions <NUM> are at least partially overlapped. A maximum thickness of each second portion <NUM> located in the edge region C2 is P, and a maximum thickness of the first portion <NUM> located in the central region C1 is Q, P > Q.

In <FIG>, the first portion <NUM> and each second portion <NUM> are overlapped in the central region C1, and the plurality of second portions <NUM> are merely provided on two sides of the first portion <NUM>. It shall be understood that the first portion <NUM> and each second portion <NUM> may be overlapped in the edge region C2, and each edge of the first portion <NUM> is provided with at least one second portion <NUM>, which can be adjusted according to actual needs. In <FIG>, in an extending direction of each second portion <NUM>, a length of each second portion <NUM> is equal to a length of the first portion <NUM>. Alternatively, the length of each second portion <NUM> may be smaller than the length of the first portion <NUM> in the extending direction of each second portion <NUM>. In addition, each side of two sides of the first portion <NUM> is provided with at least two second portions <NUM>, and the two second portions <NUM> are arranged in sequence in the extending direction of each second portion <NUM>. There is a same interval between any two adjacent second portions <NUM>, etc. There is no restriction on the interval between adjacent second portions <NUM>.

It shall be understood that the adhesive layer <NUM> provided in the disclosure has the central region C1 and the edge region C2 at least partially surrounding the central region C1. The adhesive layer <NUM> includes a first portion <NUM> and a plurality of second portions <NUM>. The first portion <NUM> includes the first material and each second portion <NUM> includes the second material. The first portion <NUM> and the second portion <NUM> are made from different materials, so that the second portion <NUM> can adopt a material with better water and oxygen isolation effect than the first portion <NUM>, which can further improve the packaging effect of the adhesive film and avoid excessive cost. The first portion <NUM> is located in the central region C1, and each of the plurality of second portions <NUM> is at least partially located in the edge region C2. In the thickness direction X, the first portion <NUM> and each second portion <NUM> are at least partially overlapped, which can ensure better connection effect between the first portion <NUM> and each second portion <NUM> and prevent the second portion <NUM> from falling off. The maximum thickness of each second portion <NUM> located in the edge region C2 is P, and the maximum thickness of the first portion <NUM> located in the central region C1 is Q, P > Q. The second portion <NUM> can protect the edge of the solar cell and play a supporting role at the edge of the solar cell, so as to avoid the edge damage of the photovoltaic module caused by the gap at the edge of the solar cell during the laminating, and improve the quality and production efficiency of the photovoltaic modules.

In some alternative embodiments, with continued reference to <FIG>, the first material is an ethylene-vinyl acetate copolymer (EVA) and the second material is a polyethylene octene co-elastomer (POE).

It shall be understood that both the EVA and the POE have the characteristics of high light transmission, ultraviolet resistance, and high temperature resistance. The EVA is the most commonly used film material for photovoltaic modules. The POE is better than EVA in water and oxygen isolation. However, the POE is more expensive than the EVA. Therefore, only the second portions located in the edge region C2 being made from the POE can better prevent water and oxygen from penetrating from the edge of the photovoltaic module, and can also avoid high cost of the adhesive layer <NUM>.

In some alternative embodiments, with continued reference to <FIG>, <NUM> ≤ Q ≤ <NUM>, Q being the maximum thickness of the first portion <NUM> located in the central region C1.

It shall be understood that in the thickness direction X, the maximum thickness of the first portion <NUM> located in the central region C1 is Q. If Q < <NUM>, the adhesion ability of the first portion <NUM> after lamination is relatively weak. If Q > <NUM>, the light transmittance of the first portion <NUM> may be affected and the cost may be increased. Therefore, by setting Q to be in a range of greater than or equal to <NUM> and less than or equal to <NUM> (<NUM> ≤ Q ≤ <NUM>), the adhesion ability of the first portion <NUM> after lamination is relatively strong and the light transmittance of the first portion <NUM> is good.

In some alternative embodiments, with continued reference to <FIG>, each second portion <NUM> includes a first sub-portion <NUM> and a second sub-portion <NUM> that are located in the central region. The first sub-portion <NUM> is disposed on a side of the second sub-portion <NUM> adjacent to the first portion <NUM>.

In the thickness direction X, the first sub-portion <NUM> and the first portion <NUM> are overlapped.

In a second direction Y, a width of the first sub-portion <NUM> ranges from <NUM> to <NUM>.

It shall be understood that the first sub-portion <NUM> is an overlapping region between the second portion <NUM> and the first portion <NUM>. In the second direction Y, the longer the width of the first sub-portion <NUM>, the larger the overlapping region between the second portion <NUM> and the first portion <NUM>, such that the effect of preventing the second portion <NUM> from falling off the edge of the first portion <NUM> is good. However, when the width of the first sub-portion <NUM> is larger than <NUM> in the second direction Y, the increase in the width of the first sub-portion <NUM> cannot further prevent the second portion <NUM> from falling off from the edge of the first portion <NUM>, and may lead to an increase in cost. Therefore, the width of the first sub-portion <NUM> being in the range of <NUM> to <NUM> in the second direction Y is a preferred range, and the first sub-portion <NUM> may have a width outside the range of <NUM> to <NUM>. The width of the first sub-portion <NUM> can be adjusted according to actual situations.

In some alternative embodiments, with continued reference to <FIG>, taking a cross section in the thickness direction and the cross section extending in the second direction Y, the first sub-portion <NUM> is rectangular, right-angled trapezoidal, or right-angled triangular in the cross section.

In other words, in a cross section perpendicular to the extending direction of each second portion <NUM>, the first sub-portion <NUM> is rectangular, right-angled trapezoidal, or right-angled triangular.

In <FIG>, the first sub-portion <NUM> is shown to be rectangular in the cross section. The first sub-portion <NUM> can also be a right-angled trapezoid, a right-angled triangle, or an irregular shape. Alternatively, mutual interpenetration between the first sub-portion <NUM> and the first portion <NUM>.

In some embodiments, a method for manufacturing an adhesive layer is provided. The adhesive layer is implemented by an adhesive layer manufacturing apparatus, and the adhesive layer manufacturing apparatus includes a base plate, a roller, and a discharge device. The base plate includes a first edge. The roller is disposed on a side of the base plate and includes an axis extending in a second direction. The discharge device, adjacent to the first edge and including a first discharge device and a plurality of second discharge devices, where the plurality of second discharge devices are configured as at least two second discharge devices, where the first discharge device is used for containing a first material and each of the at least two second discharge devices is used for containing a second material. The method includes following operations. The first material and the second material are heated through the first discharge device and the plurality of second discharge devices simultaneously, until the first material and the second material are melted. The roller is rotated about the axis. The first discharge device and the at least t wo second discharge devices discharge simultaneously. The first material is positioned between adjacent second materials, and the first material and the second materials are propagated along a third direction on a surface of the base plate, where the third direction is perpendicular to the second direction. The adhesive layer is formed by extruding the first material and the second materials by the base plate and the roller.

In some alternative embodiments, referring to <FIG>, and <FIG>, <FIG> is a schematic view illustrating an adhesive layer manufacturing apparatus for manufacturing the adhesive layer, and <FIG> is a flow chart illustrating a method for manufacturing an adhesive layer by the adhesive layer manufacturing apparatus, which illustrate a specific embodiment of the method for manufacturing the adhesive layer <NUM> provided in the disclosure. The adhesive layer <NUM> provided in the disclosure is manufactured by the adhesive layer manufacturing apparatus, and the adhesive layer manufacturing apparatus includes a base plate <NUM>, a roller <NUM>, and a discharge device <NUM>.

The base plate <NUM> includes a first edge <NUM>. The roller <NUM> is disposed on a side of the base plate <NUM>. The roller <NUM> includes an axis <NUM> extending in a second direction Y. The discharge device <NUM> is adjacent to the first edge <NUM>, and includes a first discharge device <NUM> and a plurality of second discharge devices <NUM>. There are at least two second discharge devices <NUM>. The first discharge device <NUM> is used for containing the first material and the second discharge device <NUM> is used for containing the second material.

The method for manufacturing the adhesive layer includes following operations.

At S1, the first material and the second material are heated through the first discharge device and the plurality of second discharge devices simultaneously, until the first material and the second material are melted.

At S2, the roller <NUM> is rotated about the axis <NUM>.

At S3, the first discharge device <NUM> and the plurality of second discharge devices <NUM> discharge simultaneously, such that the first material is positioned between adjacent second materials, and the first material and the second materials are propagated along a third direction Z on a surface of the base plate <NUM>, where the third direction Z is perpendicular to the second direction Y.

At S4, the base plate <NUM> and the roller <NUM> extrude the first material and the second materials to form the adhesive layer <NUM>.

It shall be understood that in <FIG>, only one first discharge device <NUM> and two second discharge devices <NUM> are illustrated. In the disclosure, there may be more than one first discharge device <NUM> and more than two second discharge devices <NUM>. The roller <NUM> rotates about the axis <NUM>. A height between the roller <NUM> and the base plate <NUM> is not changed, which ensures that a thickness of the adhesive layer <NUM> formed by extrusion of the roller <NUM> is uniform. The first discharge device <NUM> and the second discharge devices <NUM> discharge simultaneously. The first material is located between adjacent second materials. After being extruded by the roller <NUM> and cooling, the first material forms a first portion <NUM> and each second material forms a second portion <NUM>. The second portions <NUM> are located on both sides of the first portion <NUM>. As the roller <NUM> rotates, the first material and the second material are propagated on the surface of the base plate <NUM> in a third direction Z, such that the first material and the second materials are transported to the roller <NUM> for extrusion, to form the adhesive layer <NUM>. During the extrusion of the roller <NUM> and the base plate <NUM>, the first material and the second material are overlapped at a junction of the first material and the second material. The first material and the second material may also penetrate each other at the junction of the first material and the second material, which helps to increase the adhesion between the first portion <NUM> and the second portions <NUM> and prevent the second portions <NUM> from peeling off from the first portion <NUM>.

In some alternative embodiments, with continued reference to <FIG>, the roller <NUM> includes a first roller <NUM>, a second roller <NUM>, and a third roller <NUM> connected in sequence in the second direction Y. The first roller <NUM> has a diameter of M, the third roller <NUM> has a diameter of N, and the second roller <NUM> has a diameter of L, L > M=N.

In the second direction Y, a length of the first roller <NUM> is L1, a length of the third roller <NUM> is L3, and a discharge width of the second material is L4, L4 > L1=L3. In the second direction Y, a length of the second roller <NUM> is L2, and a discharge width of the first material is L5, L5 < L2.

In other words, in the second direction Y, a width of a discharge port of each second discharge device <NUM> is L4, and a width of a discharge port of the first discharge device <NUM> is L5.

It shall be understood that the first discharge device <NUM> corresponds to the second roller <NUM>, and two second discharge devices <NUM> respectively correspond to the first roller <NUM> and the third roller <NUM>. The base plate <NUM> and the roller <NUM> cooperatively extrude the first material and the second materials to form the adhesive layer <NUM>. A side of the base plate <NUM> close to the roller <NUM> is a fixed plane, and a thickness of the adhesive layer <NUM> depends on a distance between the roller <NUM> and the base plate <NUM>. The roller <NUM> has the axis <NUM>. The first roller <NUM> has the diameter of M, the third roller <NUM> has the diameter of N, and the diameter of the second roller <NUM> is L, where L > M=N, such that a distance between the first roller <NUM> and the base plate <NUM> is equal to a distance between the third roller <NUM> and the base plate <NUM>, and is greater than a distance between the second roller <NUM> and the base plate <NUM>. The first roller <NUM> and the third roller <NUM> extrude the second material with the base plate <NUM> respectively, and the second roller <NUM> and the base plate <NUM> extrude the first material, such that the first portion <NUM> is formed and the plurality of second portions <NUM> are respectively formed. Therefore, along the thickness direction X, the maximum thickness of each second portion <NUM> is P, and the maximum thickness of the first portion <NUM> is Q, P > Q, which can protect the edge of the corresponding solar cells and play a supporting role at the edge of the corresponding solar cells, thus avoiding the edge damage of the photovoltaic module caused by the gap at the edge of the solar cell during the laminating. In the second direction Y, the length of the first roller <NUM> is L1, the length of the third roller <NUM> is L3, and the discharge width of the second material is L4, where L4 > L1=L3. In the second direction Y, the length of the second roller <NUM> is L2, and the discharge width of the first material is L5, where L5 < L2. Since L5 < L2, the second material can be extruded into the central region C1 during the extrusion of the roller <NUM> and the base plate <NUM>, so that the first material and the second material may be overlapped.

In some alternative embodiments, with continued reference to <FIG>, the first material in the first discharge device <NUM> may be heated to <NUM> to <NUM>, and the second material in the second discharge device <NUM> may be heated to <NUM> to <NUM>.

It shall be understood that since the first material and the second material have different melting point temperatures, the melting of the first material and the second material can be ensured by heating the first material filled in the first discharge device to <NUM> to <NUM> and heating the second material filled in each second discharge device <NUM> to <NUM> to <NUM>.

In some alternative embodiments, with continued reference to <FIG>, a discharge flow rate of the first discharge device <NUM> is in a range of <NUM> meter per minute (m/min) to <NUM>/min, and a discharge flow rate of each second discharge device <NUM> is in a range of <NUM>/min to <NUM>/min.

It shall be understood that if the first material is EVA, and the second material is POE, since a friction force of the EVA is greater than that of POE, the EVA is more difficult to discharge than POE. Therefore, to ensure smoothness of the adhesive layer <NUM>, a discharge flow rate of the EVA is generally set to be greater than that of the POE. Under the condition that a rotation rate of the roller <NUM> is determined, if the discharge flow rate of the first material of the first discharge device <NUM> and the discharge flow rate of the second material of each second discharge device <NUM> are all less than <NUM>/min, a discharge amount of the first material and the second material may be too little, which may result in uneven or thin adhesive film formed. If the discharge flow rate of the first material of the first discharge device <NUM> and the discharge flow rate of the second material of each second discharge device <NUM> are all greater than <NUM>/min, there may be excessive discharge of the first material and the second material, such that the roller <NUM> cannot effectively extrude the first material and the second material.

Alternatively, if the first material and the second material include same materials, the friction force of the first material is the same as that of the second material, and in this case, to ensure smoothness of the adhesive layer <NUM> and the maximum thickness of each second portion to be greater than the maximum thickness of the first portion, the discharge flow rate of the second material may set to be greater than that of the first material.

In some alternative embodiments, with continued reference to <FIG>, the rotation rate of the roller <NUM> ranges from <NUM> rotations per minute (RPM) to <NUM> RPM.

It shall be understood that when the discharge flow rate of the first material of the first discharge device <NUM> and the discharge flow rate of the second material of the second discharge device <NUM> are determined to be in the range of <NUM>/min to <NUM>/min, if the rotation rate of the roller <NUM> is less than <NUM> RPM, the efficiency of the roller <NUM> is slow. If the rotation rate of the roller <NUM> is greater than <NUM> RPM, the roller <NUM> cannot effectively extrude the first material and the second material.

In some alternative embodiments, <FIG> is a schematic plan view of a photovoltaic module, and <FIG> is a cross-sectional view of the photovoltaic module in direction A-A' of <FIG>, which are specific embodiments of the photovoltaic module <NUM> provided in the disclosure. As illustrated in <FIG> and <FIG>, the photovoltaic module <NUM> includes a glass cover plate including a first glass cover plate <NUM> and a second glass cover plate <NUM> that are disposed opposite to each other in a thickness direction X.

At least one adhesive layer <NUM> is positioned between the first glass cover plate <NUM> and the second glass cover plate <NUM>. The at least one adhesive layer <NUM> includes a first adhesive layer <NUM> and a second adhesive layer <NUM> opposite to each other.

It shall be understood that each of the at least one adhesive layer <NUM> is an adhesive layer described in any foregoing embodiment, which are not repeated herein.

At least one solar cell <NUM> is disposed between the first adhesive layer <NUM> and the second adhesive layer <NUM>.

<FIG> and <FIG> only describes the double-glass module as an example of the photovoltaic module <NUM>, including the adhesive layer <NUM> in the above-mentioned embodiment. It shall be understood that the photovoltaic module <NUM> provided in the embodiment of the disclosure may also be other photovoltaic modules <NUM> having the adhesive layer <NUM>, such as a single-glass module. The photovoltaic module <NUM> provided in the embodiment of the disclosure has the beneficial effect of the adhesive layer <NUM> provided in embodiments of the disclosure. For details, reference may be made to the specific description of the adhesive layer <NUM> in the above embodiments, which are not be repeated herein.

In some alternative embodiments, with continued reference to <FIG> and <FIG>, the splice adhesive film <NUM> includes a first adhesive layer <NUM> and a second adhesive layer <NUM> disposed opposite to each other in the thickness direction X. The at least one solar cell <NUM> is positioned between the first adhesive layer <NUM> and the second adhesive film <NUM>. The at least one solar cell <NUM> each have a thickness D along the thickness direction X, where <NUM>. 4D ≤ P-Q ≤ <NUM>.

Referring to <FIG> and <FIG>, the first adhesive layer <NUM> and the second adhesive layer <NUM> are disposed opposite to each other in the thickness direction X. The at least one solar cell <NUM> is positioned between the first adhesive layer <NUM> and the second adhesive layer <NUM>. The first glass cover plate <NUM> is provided on a side of the first adhesive layer <NUM> away from the second adhesive layer <NUM>. The second glass cover plate <NUM> is provided on the side of the second adhesive layer <NUM> away from the first adhesive layer <NUM>. After the photovoltaic module <NUM> is laminated, the first adhesive layer <NUM> and the second adhesive layer <NUM> wrap the at least one solar cell <NUM>, which can effectively isolate water and oxygen. In addition, <FIG> schematically illustrates that the first portion <NUM> and each second portion <NUM> are overlapped. In an overlapping region between the first portion <NUM> and each second portion <NUM>, the second portion <NUM> is located on a side of the first portion <NUM> away from the solar cell <NUM> in the thickness direction X, which can further prevent water and oxygen penetration. In the thickness direction X, the thickness of each solar cell <NUM> is D, where <NUM>. 4D ≤ P-Q ≤ <NUM>. If P-Q is less than <NUM> D (P-Q < <NUM> D), the second portion <NUM> of the first adhesive film <NUM> and the second portion <NUM> of the second adhesive layer <NUM> has a relatively large spacing, such that the effect of preventing water and oxygen penetration and supporting is poor. If P-Q is greater than <NUM> D (P-Q > <NUM> D), a large stress may be generated on the second portion <NUM> during the laminating. In some embodiments, P-Q=<NUM>/<NUM> D, which can ensure that one side of each of the at least one solar cell <NUM> is close to the first adhesive layer <NUM> and the other side of each of the at least one solar cell <NUM> is close to the second adhesive layer <NUM> during laminating of the photovoltaic module <NUM>. In addition, there is no gap between the first adhesive layer <NUM> and the second adhesive layer <NUM> in the edge region C2, so as to avoid edge damage of the photovoltaic module <NUM> during the laminating.

As can be seen from the above embodiments, the adhesive layer provided in the disclosure at least realizes the following beneficial effects.

Claim 1:
A photovoltaic module (<NUM>), comprising:
at least one glass cover plate, comprising a first glass cover plate (<NUM>) and a second glass cover plate (<NUM>) that are disposed opposite to each other in a thickness direction;
at least one adhesive layer disposed between the first glass cover plate (<NUM>) and the second glass cover plate (<NUM>) and comprising a first adhesive layer (<NUM>) and a second adhesive layer (<NUM>) which are opposite to each other; and
a plurality of solar cells (<NUM>) disposed between the first adhesive layer (<NUM>) and the second adhesive layer (<NUM>), wherein each of the at least one adhesive film comprises:
a first portion (<NUM>), wherein the first portion (<NUM>) includes a first material and is disposed in a central region (C1) of the adhesive film (<NUM>); and
a plurality of second portions (<NUM>), wherein each of the plurality of second portions (<NUM>) includes a second material and is at least partially disposed in an edge region (C2) of the adhesive film (<NUM>), the edge region (C2) at least partially surrounding the central region (C1);
wherein the first material and the second material are different materials, the first portion (<NUM>) and each of the plurality of second portions (<NUM>) are at least partially overlapped in a thickness direction (X), and a maximum thickness P of each of the plurality of second portions (<NUM>) disposed in the edge region (C2) is greater than a maximum thickness Q of the first portion (<NUM>) disposed in the central region (C1) in the thickness direction (X),
characterized in that,
in the thickness direction (X), each of the plurality of solar cells has a thickness of D, wherein <NUM>.4D≤P-Q≤<NUM>.6D.