TW201408381A - Pyrolysis curtain-style supersonic spray coating system - Google Patents

Abstract

A Pyrolysis curtain-style supersonic spray coating system is provided. The spray system includes a heating device for a usage of heating the surface of substrate, a sizing provider for not only store but also provide sizing, a curtain-style supersonic spray device, which nebulizes coating sizing while spraying, a maternal air floating board for making substrate float, a chain-displacement device for moving and replacing substrate, and a air recycle device, which recycle the air during the spay process.

Description

Thermal cracking ultrasonic curtain spray system

The present invention relates to a production process system for a film substrate, and more particularly to a system and method for forming a solar cell film in a non-vacuum environment by a thermal cracking process using a curtain type ultrasonic atomizing spray device.

The development trend of silicon solar cells is to reduce costs and improve efficiency. In order to reduce the cost by using the use of raw materials, various devices are developed toward thin silicon wafers, and the trend of thinning will cause the problem of chip fragmentation to become more serious. Therefore, the future development trend of process equipment will also move toward the whole line. How to improve the efficiency of twin crystal solar cells and reduce manufacturing costs is the focus of future technological development. The development of twin crystal solar cell technology with an efficiency of more than 20% is also a key technology for urgent needs.

Key technologies for high-efficiency twinned solar cell structures, including forward-collecting inverted pyramid structures, selective emitters, double-layer anti-reflective layers, backside passivation films, and backside electrodes are all produced in expensive yellow-light processes and vacuum processes. As a result of the difficulty of mass production, the industry is committed to reducing its production costs and introducing mass production.

At present, the best passivation film material is recognized as aluminum oxide film. Alumina coating equipment generally uses equipment such as ALD and PECVD. Both of them need to be coated in a vacuum environment, and the expensive raw material methyl aluminum is used, so the overall equipment is expensive and the coating rate is too slow. The mass production is difficult, so the development of non-vacuum thermal cracking spray alumina equipment will have two advantages of low equipment cost and low material cost, and has strong competitiveness. Ultrasonic spraying equipment, because it can effectively use the oscillation to make the slurry evenly coated on the substrate, and the area of the sprayable area is getting larger and larger. In addition to the passivation film coating, CIGS, transparent conductive film and anti-reflective film can be used. application.

One of the key processes for PERL (Passivated Emitter, Rear Locally-diffused) structured solar cells is the back passivation layer, in which the aluminum oxide film is currently the best material for the back passivation film, and the current alumina passivation film is plated with ALD (Atomic). Layer deposition) and PECVD (Plasma enhanced Chemical vapor depostion), although the ALD-plated aluminum oxide film has been applied to the back passivation layer, its quality and efficacy have been confirmed, but since only one atomic layer is coated with a film thickness of about 0.5 nm per coating cycle, Therefore, the plating rate is slow to limit its application on solar cells. Although PECVD equipment has a better coating rate, high vacuum and plasma systems increase equipment costs and cannot be mass-produced. Under the consideration of reducing production costs, current solar cells The industry still has doubts about its application.

The main object of the present invention is to effectively solve the problems of porosity and micro crack caused by two processes of general spraying and post-heat treatment, resulting in a film quality far less than that of a vacuum process.

The thermal cracking spray system of the present invention promotes a more precise and uniform spray of the slurry. It can work in a non-vacuum environment. Compared to ALD or PECVD, it is not only low cost but also effective in increasing productivity. The atomization technology can effectively crack the liquid into tiny droplets and concentrate on spraying in local blocks to improve the uniformity and quality of the coating film, so that different slurry can be effectively and uniformly mixed, and then through the high temperature conditions on the substrate. The thermal cracking and chemical reaction are completed to form the desired Al ₂ O ₃ passivation layer. In addition, the temperature also limits the film quality and uniformity of the film, so a cooling and heating control system is required to solve the problem of spraying.

The pyrolysis spraying system disclosed in the present invention comprises a heating device for heating a substrate, a slurry supply device for storing and supplying the slurry required for spraying the substrate, and a curtain type ultrasonic atomizing spraying device for The slurry is atomized and the slurry is sprayed in a curtain shape, and the atomized slurry is cracked and then reacted to form a film on the substrate. A feed air floating mechanism and an air flotation mechanism are used to float the substrate. a chain-driven shifting device for adjustable speed, fixed-speed movement and positioning of the substrate, a gas recovery device for recovering the gas dissipated during the spraying process; wherein the curtain-type ultrasonic spraying device comprises an oscillator device, An oscillator thermostat, an atomization tank, an atomizing gas storage tank, an air knife and a wind knife thermostat, the oscillator device is fixed on the base. The atomization tank body has a slurry injection port, a slurry outlet, a fluid injection port and a fluid outlet. The lower layer of the atomization tank stores the cross-linking fluid, the upper layer stores the slurry, and the upper and lower layers are separated by a partition layer. The slurry required for spraying is injected into the atomization tank body through the slurry injection port, and the cross-linking fluid required for atomization is injected by the fluid. The inlet injection, the fluid injection port, the fluid outlet and the oscillator thermostat form a circulation loop that provides an optimal operating temperature for the oscillator oscillation. An atomizing gas storage tank is disposed above the atomizing tank body, and the atomizing gas storage tank has an air inlet for inputting gas and a gas source After entering the atomizing gas storage tank, the atomized slurry is taken out of the spray by an air knife.

The wind cutter has a fluid injection port, a fluid outlet and a wind knife thermostat. The fluid injection port, the fluid outlet and the air knife thermostat form a circulation loop for maintaining the air knife temperature.

The gas recovery device has an upper and a lower mist collector for recovering the mist which is dissipated during the spraying process, and filtering and cooling the toxic gas and discharging it by the gas discharge device.

The slurry supply device comprises a slurry storage tank having a slurry replenishing port, a slurry output port, and a slurry recovery injection port, wherein the slurry output port passes through the pipeline and delivers the slurry through the pump Feeding to the curtain type ultrasonic spraying device, the slurry output port, the slurry recovery injection port and the atomization tank body form a slurry circulation loop for circulating the slurry between the slurry storage tank and the spraying device. Continuous dosing.

The air floating mechanism has a bottom gas inlet and a surface spray outlet, wherein the air floating mechanism floats the upper substrate and is not in contact with the air floating mechanism, and the air floating mechanism includes a feed air floating mechanism for heating and lifting the substrate. A discharge air float mechanism for cooling and lifting the substrate.

The heating device comprises a plurality of precision IR heating modules capable of setting the temperature, and is arranged above the inlet of the substrate, and can be heated by the stepwise heating, so that the substrate is gradually heated from the low temperature to the required temperature, so that the substrate reaches the design temperature.

The shifting device is configured to transport the substrate, and the substrate is sequentially passed through the feeding air floating mechanism, the heating device, the curtain type ultrasonic spraying device and the discharging air floating mechanism.

The gas discharge device is disposed above the heating device, and comprises a row of fans, a heat dissipating mechanism, and a venting port. The gas discharging device cools the hot air to the exhaust pipe and collects by filtration.

The spraying system of the invention comprises a heating device for heating the substrate, a slurry supply device for storing and supplying the slurry required for spraying the substrate, and a curtain type ultrasonic atomizing spraying device for atomizing the slurry And spraying the slurry in the form of a curtain, so that the atomized slurry is cracked and then reacted to form a film on the substrate, a feed air floating mechanism, and an air flotation mechanism for floating the substrate, a chain The displacement device is used for adjustable speed, constant speed movement and positioning of the substrate, and a gas recovery device for recovering the gas which is dissipated during the spraying process.

Figure 1 shows the main structure (1) of the pyrolysis ultrasonic curtain spray system, including a curtain type ultrasonic atomizing spray device (2), a slurry supply device (3), a gas recovery device (4), Air floatation mechanism (5), heating device (6), displacement device (7), gas discharge device (8), substrate (9) and curtain-like atomized slurry (10).

2 is a view showing a pyrolysis ultrasonic curtain type spraying device (2) of the present invention, which comprises a base (21), an oscillator device (22), an atomization tank body (23), and a diaphragm ( 24) a first diaphragm pressing plate (25), a second diaphragm pressing plate (26), an atomizing gas storage tank (27) and a wind knife (28), wherein the oscillator device is fixed on the base, The atomization tank has a slurry injection port (23a), a slurry outlet (23b), a fluid injection port (23c) and a fluid outlet (23d). The lower layer of the atomization tank stores the cross-linking fluid, the upper layer stores the slurry, and the upper and lower layers are separated by a membrane layer, and the slurry required for spraying is injected into the atomization tank body through the slurry injection port (23a), and the interconnecting fluid required for atomization is atomized. Injected by the fluid injection port (23c), the fluid injection port (23c) and the fluid outlet (23d) form a circulation loop with the oscillator thermostat (23e) to provide an optimal operating temperature for the oscillator oscillation. Vibrating the fluid through the oscillator device (22) to atomize the slurry in the atomization tank. A diaphragm (24) is disposed above the atomization tank to prevent the atomized slurry from being dissipated, and the first diaphragm plate is disposed above the diaphragm. (25) and a second diaphragm platen (26) for fixing the diaphragm and preventing leakage of the atomizing gas. The atomized slurry is stored in the atomizing gas storage tank (27), and the air source required for the air knife (28) is entered by the air inlet (27a), and the atomized slurry is ejected by the air knife (28). The wind cutter has a fluid injection port (28a), first-class The body outlet (28b) and a wind knife thermostat (28c), the fluid injection port, the fluid outlet and the air knife thermostat form a circulation loop for maintaining the air knife temperature.

Figure 3 is a slurry supply device. The slurry is filled into the storage tank (34) by the slurry replenishing port (33), and the slurry output port (31) is passed through the pipeline to transport the slurry through the pump to the curtain type super Sound wave spraying device (2). The lower layer of the atomization tank body (23) stores the cross fluid, the upper layer stores the slurry, and the upper and lower layers are separated by a membrane layer, and the slurry required for spraying is injected into the atomization tank body from the slurry injection port (23a). The slurry output port (31), the slurry recovery injection port (32) and the atomization tank body (23) form a slurry circulation loop for circulating the slurry between the slurry storage tank and the spraying device. Quantitative feeding.

Figure 4 is a view showing the air floating mechanism (5) disclosed in the present invention. In order to prevent the substrate (9) from being scratched by the mechanical component during the spraying process, the air-floating mechanism is used to generate an upwardly ejected airflow to spray the substrate in a floating state. The process, the air floatation mechanism comprises a feed air float mechanism (51) and a discharge air float mechanism (52), the feed air float mechanism is arranged before the spray device, and a heating module (53) is arranged in the feed air float mechanism for Increase the temperature of the gas. The air floatation mechanism further comprises a discharge air float mechanism, and the discharge air float mechanism is disposed behind the spray device.

Figure 5 is a diagram showing a heating device (6) according to the present invention. The heating device comprises a plurality of temperature-programmable precision IR heating modules (61) disposed above the substrate inlet, and the heater temperature setting near the substrate inlet is the lowest. The temperature set by the remaining heaters is gradually increased, so that the substrate temperature can be gradually increased to 500 °C.

Figure 6 is a view showing a displacement device (7) according to the present invention. The displacement device includes a drive motor (71) and a chain (72), and a plurality of traction units (73) are arranged on the chain, and the chain is moved by the traction. The unit moves the substrate to move.

The method of spraying the thermally cracked ultrasonic curtain substrate of the present invention will now be described. The substrate is first placed at the front end of the feed air floating mechanism, and the substrate is floated and floated by the feed air floating mechanism, and then the substrate is guided by the shifting device to enter the heating device, and sequentially passes through a plurality of heaters capable of setting the temperature. The substrate temperature is gradually increased to the required cracking Temperature, the substrate is heated and sprayed, and an ultrasonic curtain type spraying device is disposed under the substrate, the ultrasonic curtain type spraying device atomizes the slurry and sprays the atomized slurry upward from the bottom of the substrate to make the atomization After the slurry is lysed, it is reacted and a film is formed on the lower surface of the substrate. The film-formed substrate is removed by the displacement device, cooled by the discharge air-floating mechanism, and finally the substrate is removed from the spray system. According to the method disclosed by the invention, the atomized slurry is sprayed upward from the bottom of the substrate, which is favorable for the direction of the airflow formed by the thermal gradient generated by the heating device in the non-vacuum high temperature state to be consistent with the spraying direction.

1‧‧‧System structure of thermal cracking equipment

2‧‧‧ Curtain type ultrasonic atomizing spraying device

21‧‧‧Base

22‧‧‧Oscillator

23‧‧‧Atomization tank

23a‧‧‧ slurry injection port

23b‧‧‧Slurry exports

23c‧‧‧ fluid injection port

23d‧‧‧Fluid outlet

23e‧‧‧Oscillator thermostat

24‧‧‧Separator

25‧‧‧First diaphragm platen

26‧‧‧Second diaphragm presser

27‧‧‧Atomizing gas storage tank

27a‧‧‧air inlet

28‧‧‧Air knife

28a‧‧‧Fluid injection port

28b‧‧‧Fluid export

28c‧‧‧Air knife thermostat

3‧‧‧Slurry supply unit

31‧‧‧Slurry outlet

32‧‧‧Slurry recovery injection port

33‧‧‧Slurry refill

34‧‧‧ Storage tank

5‧‧‧Air floatation mechanism

51‧‧‧Incoming air flotation mechanism

52‧‧‧Outlet air floatation mechanism

53‧‧‧heating module

54‧‧‧ gas inlet

55‧‧‧ gas export

6‧‧‧ heating device

61‧‧‧Precision IR heating module

62‧‧‧ fixed plate

7‧‧‧Shift device

71‧‧‧Drive motor

72‧‧‧Chain

73‧‧‧ traction unit

74‧‧‧Substrate entry position

75‧‧‧Substrate output position

9‧‧‧Substrate

10‧‧‧ Curtain-like atomized slurry

Figure 1 shows the main structure of a pyrolysis ultrasonic curtain spray system

Figure 2 is a curtain type ultrasonic atomizing spray device

Figure 3 is a slurry supply device

Figure 4 is an air flotation mechanism

Figure 5 is a heating device

Figure 6 is a shifting device

1‧‧‧Thermal cracking ultrasonic curtain spray system

2‧‧‧ Curtain type ultrasonic atomizing spraying device

3‧‧‧Slurry supply unit

4‧‧‧ gas recovery unit

5‧‧‧Air floatation mechanism

51‧‧‧Incoming air flotation mechanism

52‧‧‧Outlet air floatation mechanism

6‧‧‧ heating device

7‧‧‧Shift device

8‧‧‧ gas discharge device

9‧‧‧Substrate

10‧‧‧ Curtain-like atomized slurry

Claims (9)

A thermal cracking curtain type ultrasonic substrate spraying system, comprising a curtain type ultrasonic atomizing spraying device for atomizing a slurry and spraying the slurry in a curtain shape, and a heating device for heating the substrate, The heating device is disposed above the substrate, and the curtain type ultrasonic atomizing spraying device is disposed under the substrate, and the atomized slurry is cracked and then reacted to form a film on the surface of the substrate. For example, the pyrolysis curtain type ultrasonic spraying system of claim 1 further comprises a slurry supply device for storing and supplying the slurry required for spraying the substrate, and a gas recovery unit for recycling the spraying process. The atomizing gas, an incoming air floating mechanism, is used for floating the substrate, an discharging air floating mechanism, for lifting the substrate, and a substrate shifting device for the fixed speed spraying and positioning of the substrate. For example, in the thermal cracking curtain type ultrasonic spraying system of claim 2, the curtain type ultrasonic spraying device comprises an oscillator, an oscillator thermostat, an atomizing tank body, and an atomizing gas storage tank. a wind knife and a wind knife thermostat device, the oscillator is fixed on the base, the atomization tank body has a slurry injection port, a slurry outlet, a fluid injection port and a fluid outlet, and the atomization tank body lower layer The fluid is stored in the upper layer, the upper layer stores the slurry, and the upper and lower layers are separated by a membrane layer. The slurry required for spraying is injected into the atomization tank from the slurry injection port, and the fluid to be atomized is injected from the fluid injection port. The inlet, fluid outlet and oscillator thermostat form a loop that provides optimum operating temperature for oscillator oscillation. An atomizing gas storage tank is disposed above the atomizing tank body, the atomizing gas storage tank has an air inlet for inputting clean gas, and the gas source enters the atomizing gas storage tank, and the atomized slurry is taken by the air knife Spray out. The thermal cracking curtain type ultrasonic spraying system of claim 3, wherein the slurry supply device comprises a slurry storage tank having a slurry replenishing port, a slurry output port, and a The slurry recovery injection port, the slurry output port transmits the slurry through the pipeline through the pump to the curtain type ultrasonic spraying device, and the slurry output port, the slurry recovery injection port and the atomization tank body form a slurry cycle A circuit for circulating the slurry between the slurry storage tank and the spraying device for continuous dosing. For example, in the thermal cracking curtain type ultrasonic spraying system of claim 4, the heating device comprises a plurality of precision IR heating modules capable of setting the temperature, and is arranged above the substrate inlet, and can be heated by the section temperature to make the substrate low temperature. Gradually heat to the desired temperature to ensure complete substrate movement. For example, in the pyrolysis curtain type ultrasonic spraying system of claim 5, the air floating mechanism has a gas inlet and a plurality of gas outlets for lifting the substrate. For example, in the thermal cracking curtain type ultrasonic spraying system of claim 6, wherein the substrate shifting device is used for transporting the substrate, and the substrate is sprayed into the spraying system at a constant speed, and sequentially passes through the feeding air floating mechanism and the heating device. , curtain type ultrasonic spraying device and discharging air floating mechanism. For example, in the thermal cracking curtain type ultrasonic spraying system of claim 7, wherein the gas recovery unit has an upper and a lower mist collector, and the recovered spraying gas is filtered. A substrate spraying method comprises: disposing a heating device on a substrate, heating the substrate, heating the substrate to a temperature of 500 ° C, and arranging a curtain type ultrasonic spraying device under the substrate to form the atomized slurry in a curtain shape Sprayed on the surface of the substrate to lyse the atomized slurry and then react on the surface of the substrate to form a film.