CN213767785U

CN213767785U - Drying oven for drying or curing solar cell silicon wafer

Info

Publication number: CN213767785U
Application number: CN202020541378.3U
Authority: CN
Inventors: 上官泉元; 庄正军; 邹开封; 范恒灵
Original assignee: CHANGZHOU BITAI TECHNOLOGY CO LTD
Current assignee: CHANGZHOU BITAI TECHNOLOGY CO LTD
Priority date: 2020-04-13
Filing date: 2020-04-13
Publication date: 2021-07-23
Anticipated expiration: 2030-04-13

Abstract

The utility model discloses an oven for drying or curing a solar cell silicon wafer, which comprises a box body, wherein the box body is provided with a first plate inlet gate valve, a first plate outlet gate valve, a gas inlet pipeline and a gas outlet pipeline; a lifting support mechanism is arranged in the box body and is used for parallelly arranging a plurality of rows of support plate supports for supporting the support plates in the vertical direction; heating plates are arranged corresponding to the upper side and the lower side of each row of support plate supports; also has a loading cavity; the loading cavity is provided with a second plate inlet gate valve and a second plate outlet gate valve corresponding to the first plate inlet gate valve; the loading cavity is communicated to the vacuumizing equipment through a first vacuum valve; and an air outlet pipeline of the box body is communicated to the loading cavity through a second vacuum valve. The utility model is placed horizontally, heated and dried by a plurality of layers of silicon wafers, and the silicon wafers can be heated uniformly by heating the two sides simultaneously, so as to realize rapid drying; the volatile organic gas can be uniformly and effectively pumped out in a vacuum pumping and air inlet mode without blowing in a large amount, so that the blowing energy consumption is effectively reduced, and the device has the advantages of high productivity and less occupied area.

Description

Drying oven for drying or curing solar cell silicon wafer

Technical Field

The utility model relates to a solar cell technical field, in particular to solar cell silicon chip is oven for drying or solidification.

Background

Photovoltaic power generation has become a technology that can replace fossil energy, relying on the ever-decreasing production costs and the increase in photoelectric conversion efficiency in recent years. Solar cells can be roughly classified into two types according to the material of the photovoltaic cell sheet: one is a crystalline silicon solar cell, including a monocrystalline silicon solar cell, a polycrystalline silicon solar cell; the other type is a thin film solar cell, which mainly comprises an amorphous silicon solar cell, a cadmium telluride solar cell, a copper indium gallium selenide solar cell and the like. At present, crystalline silicon solar cells using high-purity silicon materials as main raw materials are mainstream products, and account for more than 80%.

In a crystalline silicon solar power generation system, one of the most central steps for realizing photoelectric conversion is a process of processing crystalline silicon into a cell for realizing photoelectric conversion, so that the photoelectric conversion efficiency of the cell also becomes a key index for embodying the technical level of the crystalline silicon solar power generation system.

Improving cell efficiency and establishing passivation contacts is critical. Because photogenerated carriers move rapidly in the silicon wafer, once the photogenerated carriers contact the surface, the photogenerated carriers are recombined and cannot be collected into current to generate power. If a special protective film is plated on the surface, such as silicon oxide, silicon nitride, aluminum oxide, amorphous silicon and the like, because of saturation of surface crystalline silicon surface chemical bonds and a charge field formed between the film and crystalline silicon, the special protective film can effectively prevent minority carriers from being compounded on the surface.

To further improve efficiency, new cell theory simulations require full coverage of the passivation layer, with carriers reaching the conductive layer overlying the passivation layer through tunneling. The HIT battery is a new battery designed based on this concept. The HIT battery is characterized in that a layer of thin amorphous silicon (3-5 nm) covers the front side and the back side of a silicon wafer, and then the surface of the amorphous silicon is plated with phosphorus-doped amorphous silicon and boron-doped amorphous silicon respectively. Due to the fact that the amorphous silicon has excellent passivation performance, the conversion efficiency of the HIT battery is greatly improved. However, the amorphous silicon passivation can only bear a low-temperature process, the amorphous silicon passivation effect is immediately lost at a temperature above 250 ℃, and the conventional silver paste needs to be sintered at 800 ℃ to achieve good conductivity and adhesion, which is not suitable for printing silver paste which is mature in application on conventional batteries. Therefore, the low-temperature silver paste is specially developed for the HIT battery, the paste is transferred to the surface of the silicon wafer through screen printing by using the low-temperature silver paste to form silver lines, the silver paste needs to be dried after being printed to remove an organic solvent carrier, and finally needs to be solidified. The drying temperature and the curing temperature of the low-temperature silver paste are only 200 ℃ or below, and the low-temperature silver paste and the silicon chip are combined through a binder in the silver paste. Generally, the low-temperature silver paste needs to be dried at 80-150 ℃ for about 10 minutes before entering the next printing process after being dried and cured, and hot air or infrared heating or combination of the hot air and the infrared heating is adopted for drying and heating (because organic gas is volatilized in the drying process, the air needs to be blown out).

Because the silver wire printing adopts a screen printing technology, the capacity of a single printer can reach 3000 pieces/hour or more, the HIT battery production needs to print silver wires (main grids and fine grids) which are arranged for many times, the next printing can be carried out after drying is needed in each printing, and after the last printing, the printing and the curing (curing at 200 ℃ for 30-60 minutes) are needed to achieve the best conductive performance of the silver wires. The printing process and the drying and curing process of one production line are connected together, so that the printing capacity and the drying and curing capacity are best matched.

In order to increase the drying and curing capacity, the prior art generally adopts a plurality of tracks of chain type to convey silicon wafers, the silicon wafers are horizontally laid on a conveying chain, and the conveying chain is dried and cured through a high temperature setting area.

There are also proposed improvements: 1. the silicon wafer is vertically placed between two clamping strips, and a plurality of rails continuously pass through a heating zone forwards in a parallel chain manner, so that the density of the silicon wafer placed in unit length is greatly increased, but the silicon wafer placed vertically is easy to break in the running process between the clamping strips, and the silver wire adhesive force is uneven due to uneven heating in the vertical direction; 2. the silicon chip is placed in the basket of flowers, once can put 50 ~ 100, and the basket of flowers is placed and is passed through the zone of heating on a chain track, and the chain is continuous forward motion in the oven, and its shortcoming is that it is difficult for getting rid of to be heated unevenly and between the silicon chip in the basket of flowers in the same silicon chip, and organic solvent stops and need a large amount of air blowing to flow between the silicon chip and the extravagant energy.

SUMMERY OF THE UTILITY MODEL

In order to solve the technical problem, the utility model provides an oven for drying or curing a solar cell silicon wafer, which comprises a box body with a drying cavity, wherein the box body is provided with a first plate inlet door valve corresponding to a feeding end and a first plate outlet door valve corresponding to a discharging end; the box body is also provided with an air inlet pipeline and an air outlet pipeline which are communicated with the drying chamber inside;

a lifting bearing mechanism is arranged in the drying chamber; the lifting and supporting mechanism comprises a lifting driving mechanism, a lifting rod driven by the lifting driving mechanism to vertically lift, and a plurality of rows of support plate supports used for supporting the support plate, wherein the support plate supports are arranged in parallel along the vertical direction of the lifting rod; heating plates are arranged corresponding to the upper side and the lower side of each row of the support plate bracket;

the specification of the carrier plate is M multiplied by N; wherein M is the number of silicon wafer rows in the moving direction of the carrier plate, namely M silicon wafers in each row; and N is the number of silicon chip rows of the carrier plate perpendicular to the movement direction, namely N silicon chips in each row.

Wherein, the lifting driving mechanism is any one of hydraulic pressure, oil pressure and a lifting motor.

The heating plate is a heating wire or a plurality of heating lamps are arranged, the longitudinal length of the heating plate is larger than that of the support plate, and the transverse length of the heating plate is larger than that of the support plate. Therefore, the carrier plate is uniformly heated up and down by a vertical heating mode and the heating area is larger than the area of the carrier plate.

Wherein, the heating lamp is an infrared lamp, a visible light lamp or an ultraviolet lamp. The silicon chip on the support plate is heated by heat generated by the light emitted by the heating lamps, and the heating plate can be provided with LED light-emitting lamps which are densely arranged or other light-emitting lamps or lamp tubes in a plane form.

The oven of above-mentioned structure, it utilizes the support plate support of multirow vertical arrangement can support the support plate that the silicon chip was equipped with of multirow simultaneously, and the upper and lower both sides through corresponding every row of support plate all are provided with the heating source, thereby can effectually realize the upper and lower while even heating of multirow support plate and dry or the solidification (because the organic gas that the solidification stage discharged is few or nothing, consequently, this oven is particularly useful for the solidification stage in order to practice thrift the energy consumption of blowing), and open the realization through admission line and outlet duct's valve and blow in order in time to discharge out the box with volatilizing organic gas on the silicon chip when drying or solidification, thereby realize the batch drying or the solidification of silicon chip fast.

The silicon wafer loading device comprises a box body, a support plate support, a chain type roller conveying line, a lifting roller conveying line and a stacking roller conveying line, wherein the support plate support is arranged in a lifting mode, and support plates loaded with silicon wafers can be conveyed into the box body one by utilizing the chain type roller conveying line and stacked one by one in a one-to-one correspondence mode through the lifting of the support plate support; moreover, each heating plate can be set to be independently controlled in temperature, and the heating mode can be a heating plate heated by distributed heating resistance wires or a heating lamp arranged to heat by light so as to enable the surface of the silicon wafer on the carrier plate to be uniformly heated up and down.

Wherein, each heating plate corresponding to the carrier plate can be respectively set for temperature and independently controlled, and the target temperature is generally set to be 80-200 ℃ so that the silicon chip on each carrier plate can be respectively controlled for heating.

The number of the carrier plates which can be stored in the box body is the number of layers on the carrier plate support, the number of the carrier plates can be matched with the time required for drying, the number of the layers is more, and the stay time of each carrier plate in the box body can be longer in order to achieve the preset capacity. For example, if 40 silicon wafers are placed on each carrier, in order to ensure that the drying time of each silicon wafer reaches 10 minutes and meet the throughput of 3600 wafers/hour, the carrier supports need to be set to 9 layers, that is, 9 carriers can be placed in the box body at the same time. In addition, for a carrier plate with an M × N specification, M is the width of the carrier plate in the running direction to represent M rows of silicon wafers, N is the length direction of the carrier plate perpendicular to the width to represent N rows of silicon wafers, wherein the larger the M value is, the wider the carrier plate is, the more silicon wafers can be placed on the carrier plate, but the occupied area of the equipment is long; similarly, the larger the value of N, the longer the carrier plate, the more silicon wafers can be placed thereon, and the higher the productivity, but the cavity becomes too wide, the deformation is difficult to control, and the uniformity of drying and curing is also difficult to control. Therefore, the carrier specification needs to be designed reasonably according to factors such as the structure of the oven, the layout of the production line, the productivity, and the like, and is usually several specifications such as 4 × 10, 6 × 10, 2 × 8, and the like.

Wherein, the inlet line on the box and the pipeline of giving vent to anger all are equipped with the valve, and the valve of opening the inlet line can let gas such as air, nitrogen gas get into, and the valve of opening the pipeline of giving vent to anger can let gas outgoing such as air, nitrogen gas that mix to have volatile organic gas to realize drying while exhausting.

In addition, in order to make the oven more suitable for the drying stage of the silicon chip and effectively improve the drying efficiency and save the blowing energy consumption for discharging volatile organic gas, on the basis of the structure, the oven is also provided with a loading cavity; the feeding end of the loading cavity is provided with a second plate inlet door valve, the discharging end of the loading cavity is provided with a second plate outlet door valve, and the second plate outlet door valve at the discharging end of the loading cavity corresponds to the first plate inlet door valve at the feeding end of the box body.

And the loading cavity is also communicated to a vacuum pumping device through a first vacuum valve.

And the air outlet pipeline of the box body is communicated to the loading cavity through a second vacuum valve.

In the structure, the loading cavity is connected with the box body through a chain type roller conveying line, the carrier plate loaded with the silicon wafers enters from a second plate inlet door valve of the loading cavity through the chain type roller conveying line, then the second plate inlet door valve, the second plate outlet door valve and the second vacuum valve are closed, and the first vacuum valve is opened so as to vacuumize the loading cavity through a vacuum pump; then opening a second vacuum valve of an air outlet pipeline connected between the loading cavity and the box body to enable the air in the box body to backfill into the loading cavity to enable the air pressure between the loading cavity and the oven to be balanced, and then opening a second plate outlet valve of the loading cavity and a first plate inlet valve of the box body to transfer the support plate to a support plate bracket in the box body; the steps are repeated to realize the stacking loading of the carrier plates on the carrier plate support, the carrier plates can be heated by correspondingly controlled heating plates while being loaded, and the carrier plates can also be heated together after being loaded in multiple layers.

After the carrier plate is transferred to the loading cavity through the rollers, the carrier plate can be vacuumized to reach a set vacuum degree (50-40000 Pa); when the carrier plate is taken out of the oven, an air inlet pipeline valve on the box body is opened to be connected with the atmosphere and clean air (CDA) is injected to the atmospheric pressure. The air exhaust and air intake mode of the oven is beneficial to realizing the rapid emission of organic gas uniformly volatilized in the oven, namely the organic gas of the oven is emitted to a tail gas treatment center through a vacuum pump communicated with the loading cavity, and the air exhaust and air intake cycle period of the oven is the cycle period of the carrier plate entering and exiting the oven, and the cycle period is about 30-60 seconds to realize the synchronous proceeding of loading, air exhaust and air intake and keep the consistent beat; the support plate can be moved out of the oven layer by layer through the chain type roller transmission line after being dried in the oven for a certain time.

Through the technical scheme, the silicon wafer is placed in a lying mode, heated and dried, and the silicon wafer can be uniformly heated through simultaneous double-side heating, so that the silicon wafer can be rapidly and uniformly dried; in addition, the volatile organic gas can be uniformly and effectively pumped out in a vacuum pumping and air inlet mode, so that a large amount of air blowing is not needed, the air blowing energy consumption is effectively reduced, and the box-type structure multilayer loading drying mode has the advantages of high productivity and small occupied area.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described below.

Fig. 1 is a schematic view of an oven structure disclosed in an embodiment of the present invention;

fig. 2 is a schematic structural view of an oven with a loading cavity disclosed in an embodiment of the present invention;

fig. 3 is a schematic view showing a carrier plate and a silicon wafer according to an embodiment of the present invention.

The figures in the drawings represent: 10. a box body; 11. a drying chamber; 121. a first plate inlet valve; 122. a first plate outlet valve; 131. an air intake duct; 132. an air outlet pipe; 14. a lifting drive mechanism; 15. a lifting rod; 16. a support plate bracket; 17. heating plates; 18. a lamp tube; 20. a loading chamber; 211. a second plate inlet valve; 212. a second plate outlet valve; 22. a vacuum pump; 221. a first vacuum valve; 222. a second vacuum valve; 30. a carrier plate; 40. and (3) a silicon wafer.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

Example 1:

referring to fig. 1 and 3, the present invention provides an oven for drying or curing a solar cell silicon wafer, including a box 10 having a drying chamber 11, the box 10 having a first gate valve 121 corresponding to a feeding end and a first gate valve 122 corresponding to a discharging end; the cabinet 10 further has an air inlet duct 131 and an air outlet duct 132 communicating with the inner drying chamber 11; a lifting bearing mechanism is arranged in the drying chamber 11; the lifting and supporting mechanism comprises a lifting driving mechanism 14, a lifting rod 15 driven by the lifting driving mechanism 14 to vertically lift, and a plurality of rows of carrier plate supports 16 arranged in parallel along the vertical direction of the lifting rod 15 and used for supporting the carrier plate 30; heating plates 17 are arranged corresponding to the upper side and the lower side of each row of carrier plate supports 16; the specification of the carrier plate 30 is mxn; wherein M is the number of rows of silicon wafers 40 in the moving direction of the carrier plate 30, i.e., M silicon wafers 40 in each row; n is the number of rows of silicon chips 40 of the carrier plate 30 perpendicular to the moving direction, i.e. N silicon chips 40 per row.

The lift driving mechanism 14 is any one of hydraulic pressure, oil pressure, and a lift motor. The heating plate 17 is heated by a thermal resistance wire or a plurality of heating lamps are arranged, the longitudinal length of the heating plate 17 is greater than that of the support plate 30, the transverse length of the heating plate 17 is greater than that of the support plate 30, and therefore the support plate 30 is uniformly heated up and down by means of up-and-down heating and the heating area is greater than that of the support plate 30. The heating lamp is an infrared lamp, a visible light lamp or an ultraviolet lamp. The silicon wafer 40 on the carrier plate 30 is heated by the heat generated by the heating lamps, and the heating plate 17 may be formed by densely arranged LED lamps or other planar lamps or tubes 18.

In this embodiment 1, the support plate supports 16 vertically arranged in multiple rows can simultaneously support multiple rows of support plates 30 with silicon wafers 40, and heating sources are disposed on the upper and lower sides of each row of support plates 30, so as to effectively achieve simultaneous heating, drying or curing of multiple rows of support plates 30 (the oven is particularly suitable for the curing stage, so as to save the blowing energy consumption), and the valves of the air inlet pipe 131 and the air outlet pipe 132 are opened to achieve blowing so as to discharge the organic gases volatilized from the silicon wafers 40 out of the box 10, thereby rapidly achieving batch drying or curing of the silicon wafers 40.

The carrier plate supports 16 are arranged in a lifting manner, and the carrier plates 30 with the silicon wafers 40 can be conveyed into the box body 10 one by utilizing a chain type roller conveying line and stacked one by one in a one-to-one correspondence manner through the lifting of the carrier plate supports 16; moreover, each heating plate 17 can be set to independently control the temperature, and the heating mode can be a heating plate 17 heated by distributed heating wires or can be a heating lamp arranged to heat the silicon wafer 40 on the carrier plate 30 up and down uniformly by using light.

Wherein, each heating plate 17 corresponding to the carrier plate 30 can be set with temperature and independently controlled, and the target temperature is generally set to 80-200 ℃ so that the silicon wafer 40 on each carrier plate 30 can be controlled to be heated.

The number of the carrier plates 30 that can be stored in the housing 10 is the number of layers on the carrier plate support 16, and the number of the carrier plates can be designed to match the time required for drying, and the larger the number of the layers, the longer the residence time of each carrier plate 30 in the housing 10 can be for the predetermined productivity. For example, if 40 silicon wafers 40 are placed on each carrier 30 (a 4 × 10 carrier 30 is used), in order to ensure that the drying time of each silicon wafer 40 reaches 10 minutes and meet the throughput of 3600 wafers/hour, the carrier supports 16 need to be set to 9 layers, that is, 9 carriers 30 can be placed in the box 10 at the same time.

Wherein, the inlet line 131 and the outlet line 132 on the box 10 are all provided with valves, the valve of opening the inlet line 131 can let air, nitrogen gas and other gases enter, the valve of opening the outlet line 132 can let the air, nitrogen gas and other gases mixed with volatile organic gases discharge, thereby realizing drying and exhausting.

Example 2:

referring to fig. 2, in order to make the oven more suitable for the drying stage of the silicon wafer 40 and effectively improve the drying efficiency and save the blowing energy consumption for discharging the volatile organic gas, on the basis of the above embodiment 1, a loading chamber 20 is further provided; the feeding end of the loading cavity 20 is provided with a second plate inlet door valve 211, the discharging end of the loading cavity 20 is provided with a second plate outlet door valve 212, and the second plate outlet door valve 212 at the discharging end of the loading cavity 20 corresponds to the first plate inlet door valve 121 at the feeding end of the box 10.

The loading cavity 20 is also communicated to the vacuum pump 22 through a first vacuum valve 221; the outlet pipe 132 of the box 10 is connected to the loading chamber 20 through the second vacuum valve 222.

The loading chamber 20 and the box 10 of this embodiment 2 are connected by a chain roller conveyor line, the carrier plate 30 with the silicon wafers 40 enters from the second plate inlet valve 211 of the loading chamber 20 by the chain roller conveyor line, and then the second plate inlet valve 211, the second plate outlet valve 212 and the second vacuum valve 222 are closed, and the first vacuum valve 221 is opened to evacuate the loading chamber 20 by the vacuum pump; then opening a second vacuum valve 222 of the air outlet pipeline 132 connecting the loading cavity 20 and the box body 10 to enable the gas in the box body 10 to backfill into the loading cavity 20 to enable the air pressure between the loading cavity 20 and the oven to be balanced, and then opening a second plate outlet valve of the loading cavity 20 and a first plate inlet valve of the box body 10 to transfer the carrier plate 30 to the carrier plate bracket 16 in the box body 10; the above steps are repeated to realize the stacking loading of the carrier plates 30 on the carrier plate support 16, and the carrier plates can be heated by the correspondingly controlled heating plate 17 while loading, or heated together after being loaded in multiple layers.

After the carrier plate 30 is transferred to the loading cavity 20 through the rollers, the carrier plate can be vacuumized to reach a set vacuum degree (50-40000 Pa); when the carrier plate 30 exits the oven, the inlet duct 131 on the chamber 10 is opened to connect to the atmosphere and inject clean air (CDA) to atmospheric pressure. The air exhaust and air intake mode of the oven is beneficial to realizing the rapid emission of organic gas uniformly volatilized in the oven, namely the organic gas of the oven is emitted to a tail gas treatment center through a vacuum pump communicated with the loading cavity 20, and the air exhaust and air intake cycle period of the oven is the cycle period of the carrier plate 30 entering and exiting the oven, and the cycle period is about 30-60 seconds to realize the synchronous proceeding of loading, air exhaust and air intake and keep the consistent beat; after the carrier plate 30 is dried in the oven for a certain time, it can be moved out of the oven layer by layer through the chain roller transmission line.

Through the technical scheme, the silicon wafer is placed horizontally, heated and dried, and the silicon wafer 40 can be uniformly heated by heating the two surfaces simultaneously, so that the silicon wafer is quickly and uniformly dried; in addition, the volatile organic gas can be uniformly and effectively pumped out in a vacuum pumping and air inlet mode, so that a large amount of air blowing is not needed, the air blowing energy consumption is effectively reduced, and the box-type structure multilayer loading drying mode has the advantages of high productivity and small occupied area.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to the above-described embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. The drying oven for drying or curing the solar cell silicon wafer is characterized by comprising a box body with a drying cavity, wherein the box body is provided with a first plate inlet gate valve corresponding to a feeding end and a first plate outlet gate valve corresponding to a discharging end; the box body is also provided with an air inlet pipeline and an air outlet pipeline which are communicated with the drying chamber inside;

2. The oven for drying or curing the solar cell silicon wafer according to claim 1, wherein the lifting driving mechanism is any one of hydraulic pressure, oil pressure and a lifting motor.

3. The oven according to claim 1, wherein the heating plate is a thermal resistance wire or a plurality of heating tubes are arranged, the longitudinal length of the heating plate is greater than that of the carrier plate, and the transverse length of the heating plate is greater than that of the carrier plate.

4. The oven according to claim 3, wherein the heating lamp is an infrared light lamp, a visible light lamp or an ultraviolet light lamp.

5. The oven for drying or curing the solar cell silicon wafer according to any one of claims 1 to 4, further comprising a loading chamber; the feeding end of the loading cavity is provided with a second plate inlet door valve, the discharging end of the loading cavity is provided with a second plate outlet door valve, and the second plate outlet door valve at the discharging end of the loading cavity corresponds to the first plate inlet door valve at the feeding end of the box body.

6. The oven for drying or curing the solar cell silicon wafer as claimed in claim 5, wherein the loading chamber is further communicated to a vacuum pumping device through a vacuum valve.

7. The oven for drying or curing the solar cell silicon wafer as claimed in claim 6, wherein the gas outlet pipeline of the box body is communicated to the loading cavity through a second vacuum valve.