CN107068802A - Improve the pretreatment unit and its processing method of polysilicon chip etching matte uniformity - Google Patents

Abstract

The invention provides the pretreatment unit for improving polysilicon chip etching matte uniformity, including a thermostat for accommodating thermostatted water and the conveying roller being arranged in thermostat, the conveying roller is placed under the thermostatted water, silicon chip to be etched is placed on the conveying roller, the conveying roller is rotated, the silicon chip motion to be etched is driven, described device also includes the air-dried mechanism of constant temperature of one and the port of export UNICOM of the thermostat.Beneficial effects of the present invention are embodied in：The polysilicon chip for needing to etch is maintained at temperature for 8 10 DEG C in advance, it is suitable with etching groove temperature, uniformity between uniformity and piece can be greatly improved in the piece of polysilicon chip matte, the aberration piece ratio of cell piece, the qualification rate of raising cell piece is reduced.

Description

Pretreatment device and treatment method for improving uniformity of etched textured surface of polycrystalline silicon wafer

technical field

The invention belongs to the technical field of solar battery components, and in particular relates to a pretreatment device and a treatment method for improving the uniformity of etched textured surfaces of polycrystalline silicon wafers.

Background technique

The manufacturing process of polysilicon cells is generally cleaning and making suede, then diffusing to make PN junction, etching and dephosphorizing silicon glass, PECVD coating, screen printing electrode sintering, and finally testing and packaging. Cleaning and etching are the first process for manufacturing solar cells. How to obtain a uniform etching texture on the surface of p-type silicon wafers and maintain the consistency of the texture of each batch of silicon wafers is an important issue considered by the cleaning section. Existing polysilicon wafers are generally directly loaded into the etching tank, and the surface temperature of the silicon wafer is 20-25 ° C. After entering the etching tank, since the temperature of the chemical solution in the etching tank is 8-10 ° C, the surface temperature of the silicon wafer The temperature difference between the chemical solution and the etching tank is large, resulting in uneven etching on the surface of the silicon wafer.

Contents of the invention

The invention provides a pretreatment device and a treatment method for improving the uniformity of the etched suede surface of a polycrystalline silicon wafer.

The purpose of the present invention is achieved through the following technical solutions:

The pretreatment device for improving the uniformity of etched suede surface of polycrystalline silicon wafers includes a constant temperature tank containing constant temperature water and transmission rollers arranged in the constant temperature tank, the transmission rollers are placed under the constant temperature water, and the silicon wafers to be etched are placed On the transmission roller, the transmission roller rotates to drive the movement of the silicon wafer to be etched, and the device also includes a constant temperature air-drying mechanism connected with the outlet end of the constant temperature tank.

Preferably, the constant temperature air-drying mechanism includes a transmission roller on the same plane as the transmission roller in the constant temperature tank, and a constant temperature air knife is arranged above the transmission roller.

Preferably, the transmission rollers are provided with upper and lower transmission rollers, and the silicon wafer to be etched is arranged between the upper and lower transmission rollers, and the upper and lower transmission rollers rotate to drive the silicon wafer to be etched for transmission.

Preferably, a solution tank is provided below the constant temperature tank, and the constant temperature tank and the solution tank are circulated through a water pump. A constant temperature control mechanism is arranged in the solution tank, and both the constant temperature tank and the solution tank are provided with There is a temperature sensor electrically connected with the constant temperature control mechanism.

Preferably, the temperature of the constant temperature water is 8-10°C, and the constant temperature water is deionized water.

Preferably, the transport rollers are provided with separation strips, and the distance between adjacent separation strips on the same transport roller is equivalent to the width of the silicon wafer to be etched.

Preferably, the device further includes a drive motor for driving the rollers to rotate.

Preferably, the discharge end of the device is sealed and connected to the feed end of the etching device.

A pretreatment method for improving the uniformity of the etched textured surface of polysilicon wafers, comprising the following steps,

S1. Constant temperature adjustment and control of the solution in the solution tank; the solution in the solution tank is controlled at a temperature of 8-10°C through a constant temperature control mechanism;

S2. Put the polysilicon wafer into the constant temperature tank, and put the polysilicon wafer between the upper and lower transmission rollers of the constant temperature tank;

S3. Inject the solution into the constant temperature tank, and keep the temperature at 8-10°C, inject the solution in the solution tank into the constant temperature tank through the water pump of Unicom, and immerse the transmission roller and the surface of the polysilicon wafer in the constant temperature tank;

S4. Put 8-10°C deionized water into the constant temperature tank, submerge the transfer rollers, so as to cool down the silicon wafer and reduce the surface temperature of the silicon wafer to 8-10°C;

S5. After the silicon wafer leaves the water bath in the constant temperature tank, it enters the constant temperature air drying mechanism. The constant temperature air knife is activated to dry the surface of the silicon wafer, and then enters the etching tank. The temperature of the constant temperature air knife is 8-10°C.

The beneficial effect of the present invention is reflected in: the polysilicon wafer to be etched is maintained at a temperature of 8-10°C in advance, which is equivalent to the temperature of the etching tank, and the intra-chip uniformity and inter-chip uniformity of the suede surface of the polycrystalline silicon wafer can be greatly improved. Reduce the ratio of the color difference film of the cell and improve the qualified rate of the cell.

Description of drawings

Figure 1: Schematic diagram of the structure of the present invention.

detailed description

The technical scheme of the present invention is specifically described below in conjunction with the examples. The present invention discloses a pretreatment device that improves the uniformity of the etched suede surface of polycrystalline silicon wafers. A constant temperature air-drying mechanism connected to the outlet end of the constant temperature tank. The discharge end of the device is closed and connected with the feed end of the etching device, and further, the constant temperature air-drying mechanism is closed and connected with the feed end of the etching device.

The constant temperature tank 2 is provided with transmission rollers placed under the constant temperature water, and the transmission rollers include an upper transmission roller 3 and a lower transmission roller 4 . The silicon wafer to be etched is arranged between the upper and lower layer transmission rollers; the device also includes a driving motor for driving the rotation of the rollers, and the rotation of the upper and lower layer transmission rollers drives the silicon wafer to be etched for transmission . The temperature of the constant temperature water is 8-10° C., and the constant temperature water is deionized water.

The constant temperature air-drying mechanism includes a transmission roller 6 on the same plane as the transmission roller in the constant temperature tank, and a constant temperature air knife 7 is arranged above the transmission roller 6 . In the present invention, the same plane is further limited to the same horizontal plane, and when the polysilicon wafer in the constant temperature tank is at the outlet end, it can well enter into the constant temperature air-drying mechanism to realize seamless docking.

In order to better control the water temperature and water volume of the deionized water in the constant temperature tank 2, a solution tank 1 is arranged below the constant temperature tank, and the constant temperature tank 2 is connected to the solution tank 1 through a water pump circulation. A constant temperature control mechanism is arranged in the tank 1, and a temperature sensor electrically connected to the constant temperature control mechanism is arranged in the constant temperature tank 2 and the solution tank 1 .

In order to carry out more quantified silicon wafer transmission, the transfer rollers are provided with separation strips 5 , and the distance between adjacent separation strips on the same transmission roller is equivalent to the width of the silicon wafers to be etched. The number of separation belts 5 used in the present invention is 4, and the transmission rollers are divided into 5 areas, so that five rows of silicon wafers can be simultaneously transported.

The following describes the pretreatment method for improving the uniformity of the etched textured surface of polysilicon wafers by using the device, including the following steps,

S1. Constant temperature adjustment and control of the solution in the solution tank; the solution in the solution tank is controlled at a temperature of 8-10°C through a constant temperature control mechanism;

S2. Put the polysilicon wafer into the constant temperature tank, and put the polysilicon wafer between the upper and lower transmission rollers of the constant temperature tank;

S3. Inject the solution into the constant temperature tank, and keep the temperature at 8-10°C, inject the solution in the solution tank into the constant temperature tank through the water pump of Unicom, and immerse the transmission roller and the surface of the polysilicon wafer in the constant temperature tank;

S4. Put 8-10°C deionized water into the constant temperature tank, submerge the transfer rollers, so as to cool down the silicon wafer and reduce the surface temperature of the silicon wafer to 8-10°C;

S5. After the silicon wafer leaves the water bath in the constant temperature tank, it enters the constant temperature air drying mechanism. The constant temperature air knife is activated to dry the surface of the silicon wafer, and then enters the etching tank. The temperature of the constant temperature air knife is 8-10°C.

Table 1 is a comparison table of the influence of the pretreatment in the present invention on the reflectivity of the final product and the prior art:

Example Prior art reflectivity Invention Technology Reflectivity 1 20.56 20.36 2 21.23 19.46 3 21.89 19.54 4 22.47 19.47 5 20.14 20.39 6 21.58 20.58 7 19.58 20.14 8 22.36 19.78 9 21.8 20.62 10 19.08 19.68 standard deviation 1.17 0.47

. The above fully shows that the method of the present invention ensures that before the product enters the etching tank, the temperature on the surface of the silicon wafer is reduced to the same temperature as the etching tank chemical solution, which not only does not affect the concentration of the etching tank chemical solution, but also can uniformly React with liquid medicine.

The present invention still has multiple specific implementation modes. All technical solutions formed by equivalent replacement or equivalent transformation fall within the protection scope of the present invention.

Claims (9)

1. improve the pretreatment unit that polysilicon chip etches matte uniformity, it is characterised in that：Thermostatted water is accommodated including one Thermostat and the conveying roller being arranged in thermostat, the conveying roller are placed under the thermostatted water, and silicon chip to be etched is placed in On the conveying roller, the conveying roller is rotated, and drives the silicon chip motion to be etched, described device also include one with it is described The constant temperature of the port of export UNICOM of thermostat air-dries mechanism.

2. the pretreatment unit that polysilicon chip etches matte uniformity is improved as claimed in claim 1, it is characterised in that：It is described Constant temperature, which air-dries mechanism, to be included the conplane delivery roll of conveying roller in thermostat, the delivery roll top are provided with constant temperature Air knife.

3. the pretreatment unit that polysilicon chip etches matte uniformity is improved as claimed in claim 1, it is characterised in that：It is described Conveying roller is provided with upper and lower layer conveying roller, and silicon chip to be etched is arranged between the upper and lower layer conveying roller, it is described it is upper, Lower floor's conveying roller is rotated, and drives silicon chip to be etched to be transmitted.

4. the pretreatment unit that polysilicon chip etches matte uniformity is improved as claimed in claim 1, it is characterised in that：It is described Solution tank is provided with below thermostat, the thermostat is connected by water pump circulation with the solution tank, set in the solution tank Thermostatic control mechanism is equipped with, the thermostat is with being provided with what is be electrically connected with the thermostatic control mechanism in the solution tank Temperature sensor.

5. the pretreatment unit that polysilicon chip etches matte uniformity is improved as claimed in claim 1, it is characterised in that：It is described The temperature of thermostatted water is 8-10 DEG C, and the thermostatted water is deionized water.

6. the pretreatment unit that polysilicon chip etches matte uniformity is improved as claimed in claim 3, it is characterised in that：It is described Width of the distance between the adjacent dividing strip being provided with conveying roller on dividing strip, same conveying roller with silicon chip to be etched Quite.

7. the pretreatment unit that polysilicon chip etches matte uniformity is improved as claimed in claim 2, it is characterised in that：It is described Device also includes the motor for driving the roller to rotate.

8. the pretreatment unit that polysilicon chip etches matte uniformity is improved as claimed in claim 1, it is characterised in that：It is described The feed end closing of the discharge end and etching device of device is connected.

9. improve the preprocess method that polysilicon chip etches matte uniformity, it is characterised in that：Comprise the following steps,

The thermostatic control of solution in S1, solution tank, control；The solution in solution tank is controlled in temperature by thermostatic control mechanism For 8-10 DEG C；

S2, polysilicon chip are put into thermostat, and polysilicon chip is put between the upper and lower layer conveying roller of thermostat；

Injection solution in S3, thermostat, and maintain the temperature at 8-10 DEG C, the solution in solution tank is injected by the water pump of UNICOM To thermostat, and submerge the conveying roller in thermostat and polysilicon chip surface；

8-10 DEG C of deionized water is passed through in S4, thermostat, did not had conveying roller, so as to give silicon chip cooling, makes silicon chip surface Temperature drops to 8-10 DEG C；

S5, silicon chip go out after the water-bath of thermostat, enter constant temperature and air-dry mechanism, constant temperature air knife starts, silicon chip surface is dried up, entered One step enters etching groove, and the temperature of the constant temperature air knife is 8-10 DEG C.