阅读说明：本技术 一种光伏电池片切割方法及用该方法制造的电池片 (Photovoltaic cell cutting method and cell manufactured by same ) 是由 蔡后敏 刘亚峰 黄晓 胡剑鸣 于 2020-05-12 设计创作，主要内容包括：本发明公开了一种光伏电池片切割方法,一、把待切割电池片放置激光划片区域；二、使用第一道激光在电池片切割位置的边缘形成第一切割线；三、使用第二道激光,其光斑沿着第一切割线的裂缝前面位置进行局部加热并沿第一切割线所在的方向并向远离所述的边缘的方向移动延伸,同时对被加热位置进行冷却,优点是该方法使得激光切割温度可以显著降低,由于切割过程中无气化或熔融,所以无粉尘产生,而且切割断裂面没有熔渣碎屑或微裂纹,提高了电池和组件的力学性能,即提高机械强度,对于非晶硅膜层的情形,同时避免破坏非晶硅膜层,减少电池片效率损失；本发明还提出一种电池片,采用所述的光伏电池片切割方法切割获得。(The invention discloses a photovoltaic cell slice cutting method, which comprises the following steps of firstly, placing a cell slice to be cut in a laser scribing area; secondly, forming a first cutting line on the edge of the cutting position of the cell slice by using a first laser; thirdly, using a second laser, locally heating the light spot of the second laser along the front position of the crack of the first cutting line, moving and extending along the direction of the first cutting line and in the direction far away from the edge, and cooling the heated position at the same time, wherein the method has the advantages that the laser cutting temperature can be obviously reduced, no dust is generated because no gasification or melting occurs in the cutting process, no slag chips or microcracks exist on the cutting fracture surface, the mechanical properties of the battery and the assembly are improved, namely, the mechanical strength is improved, and for the situation of the amorphous silicon film layer, the amorphous silicon film layer is prevented from being damaged, and the efficiency loss of the battery piece is reduced; the invention also provides a cell slice which is obtained by cutting by adopting the photovoltaic cell slice cutting method.)

1. A photovoltaic cell slice cutting method is characterized in that: the method comprises the following steps:

firstly, placing a battery piece to be cut in a laser scribing area;

secondly, forming a first cutting line on the edge of the cutting position of the cell slice by using a first laser;

and thirdly, using a second laser, locally heating the spot of the second laser along the position in front of the crack of the first cutting line, moving and extending along the direction of the first cutting line and in the direction far away from the edge, and cooling the heated position.

2. The method for cutting a photovoltaic cell sheet according to claim 1, wherein: the length of the first cutting line is in the range of (0, 5 cm), and the depth is in the range of [ 20% and 100% of the thickness of the cell.

3. The photovoltaic cell sheet cutting method according to claim 2, characterized in that: the length of the first cutting line cutting seam is 2-3 cm.

4. The photovoltaic cell sheet cutting method according to claim 2, characterized in that: the cutting depth of the first cutting line is 40-60%.

5. The method for cutting a photovoltaic cell sheet according to claim 1, wherein: and in the third step, the cutting position is cooled by air cooling.

6. The method for cutting a photovoltaic cell sheet according to claim 1, wherein: and in the third step, the cutting position is cooled by liquid cooling.

7. The method for cutting a photovoltaic cell sheet according to claim 1, wherein: and the first laser cuts the front side or the back side of the cell piece.

8. The method for cutting a photovoltaic cell sheet according to claim 1, wherein: the cutting temperature of the second laser is lower than 200 ℃.

9. A battery piece, characterized in that: obtained by cutting by the photovoltaic cell sheet cutting method according to any one of claims 1 to 8.

Technical Field

The invention relates to the technical field of battery piece cutting, in particular to a photovoltaic battery piece cutting method and a battery piece manufactured by the method.

Background

In the photovoltaic market, the half-sheet assembly is popular with customers due to small electrical loss and high assembly power and efficiency, and rapidly occupies the market. The half-chip assembly packaging is to cut the whole cell into half-chips by laser, most of the currently adopted laser is n seconds of infrared, the temperature is over 1000 ℃, the contacted silicon is directly gasified or melted, so that a V-shaped groove is formed on the surface of a silicon chip, and then the half-chip assembly packaging is mechanically broken into half-chips. According to the prior art, the efficiency of surrounding batteries is often affected due to the excessively high cutting temperature, so that the packaging power of the assembly is reduced; particularly, for the Hit battery, the amorphous silicon film layer of the Hit battery is basically damaged at the temperature of over 220 ℃, and the efficiency of the Hit battery is reduced more by using the existing laser cutting method. Moreover, the existing cutting method can cause silicon materials to form a large amount of dust in the cutting process, and the dust has adverse effect on the working environment around equipment.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the method has the advantages that the defects of the prior art are overcome, the laser cutting temperature can be obviously reduced, the damage of high temperature to the battery is reduced, the reduction of the battery efficiency grade is reduced, and the power of the half-piece assembly is improved; particularly, the battery sensitive to temperature, such as a Hit battery, is facilitated, and the efficiency is improved more obviously; because no gasification or melting occurs in the cutting process, no dust is generated, and no slag chips or microcracks exist on the cutting fracture surface, the mechanical properties of the battery and the assembly are improved, namely the mechanical strength is improved, and for the situation of the amorphous silicon film layer, the amorphous silicon film layer is prevented from being damaged, and the efficiency loss of the battery piece is reduced; the half-sheet assembly is obtained by cutting the photovoltaic cell sheet by the photovoltaic cell sheet cutting method.

The technical scheme adopted by the invention is as follows: provided is a photovoltaic cell slice cutting method, which comprises the following steps:

firstly, placing a battery piece to be cut in a laser scribing area;

secondly, forming a first cutting line on the edge of the cutting position of the cell slice by using a first laser;

and thirdly, using a second laser, locally heating the spot of the second laser along the position in front of the crack of the first cutting line, moving and extending along the direction of the first cutting line and in the direction far away from the edge, and cooling the heated position.

After adopting the technical scheme, compared with the prior art, the invention has the following advantages: because the cutting principle is different, the cutting principle of the invention uses a temperature gradient, specifically, a light spot of a second laser is locally heated at a position in front of a crack along a first cutting line, and the locally heated position is cooled to reduce the temperature of the laser reaching the surface of the battery, so that a non-uniform temperature field and a temperature gradient are formed at the position of the light spot, the temperature gradient induces the generation of thermal stress, so that the crack cracks open the battery piece along the moving direction of the light spot, the light spot moves along the direction of the first cutting line in the direction far away from the edge of the first cutting line, the position where the light spot goes is locally heated, the heated position and the adjacent unheated position of the battery piece have different temperatures, so that a temperature field is formed, different thermal stresses (thermal expansion and contraction) are formed by different temperatures, different temperature fields can cause different tensile stress and different compressive stress at different places, thereby achieving the purpose of cutting the battery piece by utilizing the temperature gradient.

Therefore, the laser cutting temperature can be obviously reduced, the damage of high temperature to the battery is reduced, the reduction of the efficiency grade of the battery is reduced, and the power of the half-chip assembly is improved; particularly, the battery sensitive to temperature, such as a Hit battery, is facilitated, and the efficiency is improved more obviously; because no gasification or melting occurs in the cutting process, no dust is generated, and no slag chips or microcracks exist on the cutting fracture surface, the mechanical properties of the battery and the assembly are improved, namely the mechanical strength is improved.

Preferably, the length of the first cutting line is in a range of (0, 5 cm), and the depth of the first cutting line is in a range of [ 20% and 100% of the thickness of the cell slice), and the improvement is favorable for cutting.

Preferably, the length of the first cutting line cutting seam is 2-3 cm, preferably 2, 2.5 or 3cm, which is beneficial to cutting, namely obtaining a cutting stress and easy to cut.

Preferably, the cutting depth of the first cutting line is 40-60% of the thickness of the cell, preferably 40%, 50% or 60%, which is beneficial to realizing no damage to the silicon wafer during cutting and splitting.

Preferably, in the fourth step, the cutting position is cooled by air cooling, and the method is simple.

Preferably, the cutting position is cooled by liquid cooling in the fourth step, so that the cooling speed is higher and the effect is good.

Preferably, the first laser is used for cutting the front side or the back side of the cell piece, and the laser cutting method is very suitable for cutting the cell piece with the power generation structure on both sides, such as a heterojunction cell piece.

Preferably, the cutting temperature of the second laser is lower than 200 ℃, which has the advantages of lower temperature and good cutting performance.

The technical scheme adopted by the invention is as follows: the photovoltaic cell piece is obtained by cutting through the cutting method.

After adopting the technical scheme, compared with the prior art, the invention has the following advantages: the photovoltaic cell slice is obtained by cutting with the method, the cut part is the cell slice, the cutting fracture surface of the cell slice has no slag chips or microcracks, the mechanical property of the cell slice is improved, namely, the mechanical strength is improved, meanwhile, the amorphous silicon film layer of the cell slice is prevented from being damaged, the efficiency loss of the cell slice is reduced, namely, the reduction of the efficiency grade of the cell is reduced, and the power of the cell slice is improved.

Drawings

Fig. 1 is a schematic diagram illustrating a method for cutting a photovoltaic cell according to the present invention.

Fig. 2 is a schematic structural diagram of a photovoltaic cell sheet in a state that a first cutting line is completed.

Fig. 3 is a schematic structural diagram of a photovoltaic cell piece cut into two parts.

Reference number 1, first cutting line.

Detailed Description

The following description is presented to disclose the invention so as to enable any person skilled in the art to practice the invention. The embodiments in the following description are given by way of example only, and other obvious variations will occur to those skilled in the art. The basic principles of the invention, as defined in the following description, may be applied to other embodiments, variations, modifications, equivalents, and other technical solutions without departing from the spirit and scope of the invention.

The figures are purely diagrammatic and not drawn to scale.

It will be understood by those skilled in the art that in the present disclosure, the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "stone", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, which are merely for convenience in describing and simplifying the description, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and thus the above-described terms should not be construed as limiting the present invention.

The invention provides a photovoltaic cell slice cutting method, which comprises the following steps:

firstly, placing a battery piece to be cut in a laser scribing area;

secondly, forming a first cutting line on the edge of the cutting position of the cell slice by using a first laser;

and thirdly, using a second laser, locally heating the spot of the second laser along the position in front of the crack of the first cutting line, moving and extending along the direction of the first cutting line and in the direction far away from the edge, and cooling the heated position.

The length of the first cutting line is in a half-open and half-closed interval (0, 5 cm), and the depth is in a half-closed and half-open interval (20 percent, 100 percent) of the thickness of the cell.