Business Line (Mr. Zeng)
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2019-03-04 10:18:00 Editor： jushong shares 0
The predecessor of Haohong Co., Ltd. is Shenzhen Kebo Purification, a well-known brand in South China, with a total of more than 2 million square meters of purification area, 20 years of purification engineering experience, a number of industry professional certificates, industry qualification certificates, the entire industry chain clean room System service provider. Today, I will introduce the purification project of the new energy clean and clean workshop.
1. Introduction to photovoltaic new energy silicon wafer
The photovoltaic new energy silicon wafer is a piece of mirror-like bright wafer processed from silicon material, which is the raw material for producing semiconductor integrated circuit chips. At present, the microelectronics industry is developing rapidly, and integrated circuit technology has entered the era of 0.18 micron or less, which has greatly stimulated the development of photovoltaic new energy silicon wafers. At the same time, the requirements for the performance parameters of photovoltaic new energy silicon wafers have also been greatly improved. The development prospects of photovoltaic new energy silicon wafers are very optimistic.
1.1 Photovoltaic new energy silicon wafer production process
In a big way, photovoltaic new energy silicon wafer production includes two major parts: silicon single crystal rod production and photovoltaic new energy silicon wafer production, which are subdivided into the following main processes:
Single Crystal Rod Growth - Single Crystal Rod Cutting and Inspection - OD Grinding - Slicing - Chamfering (Circular Edge) - Grinding / Grinding Sheet Inspection - Etching (Chemical Etching, LP-CVD + AP-CVD, etc.) - PTA Heat treatment - back damage treatment - polishing (ML rough throw, ML fine throw) - washing - quality inspection - clean packaging
From the growth of the single crystal rod to the outer diameter grinding to the silicon single crystal rod production process, the process after the slicing is the photovoltaic new energy silicon wafer production process. Let's take a Japanese silicon wafer factory as an example to introduce the design scheme of air conditioning purification system and automatic control system for photovoltaic new energy silicon wafer production process.
1.2 Environmental control requirements for each production process
A silicon wafer factory produces 4 to 6 inches of photovoltaic new energy silicon wafers with a production capacity of 4.8 million pieces per year. The company's photovoltaic new energy silicon wafers are used in the fabrication of discrete devices, power components and specialty integrated circuits.
2, air conditioning purification system
The design of air conditioning purification is closely integrated with the layout of the process and the production process. The air conditioning purification systems of different types and different uses have their own characteristics. The air conditioning purification system scheme for the production process of photovoltaic new energy silicon wafers is introduced below.
2.1 Air conditioning system
1 The slice chamber, the chamfer chamber and the grinding chamber have only temperature control requirements. The air-cooled heat pump split cabinet air conditioner (PAC) is used to ensure the room temperature requirement. The indoor unit is placed in the workshop, and the air duct is used. Layer louver tuyere side air supply mode; outdoor unit is placed on the roof. The air volume of the slicing chamber is large, and the fresh air is supplemented by direct evaporative heat pump type roof air conditioners S1-1 and S1-2. The workshop has dust-proof requirements, and the air-cooling heat pump split-type air conditioner has a medium-efficiency filter at the air return (air dust counting efficiency: ≥60%, for ≥1μm particles), the same roof type air conditioner needs two-stage filter .
The schematic diagram is shown in the figure:
2 Furnace room and BSD room only have temperature control requirements. Air-cooled electric heating split type air conditioner (PAL) is used to ensure room temperature requirements. The indoor unit is placed in the workshop, and the air duct is connected. Wind mode; the outdoor unit is placed on the roof. The fresh air is coming from the adjacent clean room. The workshop has dustproof requirements, and the air-cooled electric heating split cabinet air conditioner has a medium efficiency filter at the air return (air dust counting efficiency: ≥60%, for ≥1μm particles).
3 The grinding inspection room has temperature and humidity control requirements, and the air-cooled electric heating split type air conditioner (PAL) is used to ensure the room temperature requirement. The indoor unit is placed in the workshop nearby, and the air duct is connected, and the square diffuser is used for sending. Wind mode; the outdoor unit is placed on the roof. After the fresh air is treated by the new air blower unit (MAU-1, 2), it is sent to the air supply pipe and sent to the indoor. The relative humidity is guaranteed by the new air blower unit. The new air unit is shared with the purification system. The workshop has dust-proof requirements, and the air-cooled electric heating split-type air conditioner has a medium-efficiency filter at the air return (air dust counting efficiency: ≥60%, for ≥1μm particles), and the new fan group is equipped with a thick and medium-efficiency filter.
2.2 Purification system
The fresh air conditioning unit (MAU) and the circulating air conditioning unit (AHU) used in the photovoltaic new energy purification engineering system use 6-11 °C chilled water, heating using 0.2 MPa steam, humidification using 0.1 MPa clean steam humidification, clean steam by Pure water is produced by a clean steam generator.
1 CP chamber purification level is 7 grades, the number of air changes is 30 times/hour, and the amount of acid used in the process equipment of CP room is more. The new air conditioning unit (MAU-3) + high efficiency filter air supply port (HEP-ABOX) The way of air conditioning. The air flow process is: fresh air inlet - coarse filter - medium efficiency filter - pre-heater - surface cooler - heater - clean steam humidification - blower - air supply pipe - high efficiency filter air supply - clean area.
2 The ML chamber has a purification level of 7 and the number of air changes is 30 times/hour. The air conditioning mode of the new air unit (MAU) + circulation unit (AHU) + high efficiency filter air outlet (HEP-ABOX) is adopted. The fresh air is connected to the MAU-1 and 2 fresh air groups from other systems.
3 CP/CVD room, LP/CVD room, clean packaging room purification level is 6 levels, the number of air changes is 50 times/hour, using new air unit (MAU) + circulation unit (AHU) + high efficiency filter air supply port (HEP -ABOX) air conditioning. The fresh air is connected to the MAU-1 and 2 fresh air groups shared by other systems.
The airflow form of the 4th and 6th cleanrooms is the air supply at the top high-efficiency filter air supply port, and the air ventilator at the lower side of the room is returned. The air flow process is: new return air mixing! Medium efficiency filter - surface cooler - blower - air supply pipe - high efficiency filter air supply port - clean area - room side lower louver return air inlet - return air pipe - new return air mixing.
5 The cleaning room and quality inspection room have a purification level of 7 and adopt the air conditioning mode of the new air unit (MAU) + circulation unit (AHU) + fan filter unit (FFU). The airflow used is the top FFU air supply, and the room side lower louver air outlet returns. The FFU coverage rate is 33%. The cleaning room and the quality inspection room have requirements for NH4+ and SQx concentrations. A chemical filter is required in the circulation unit (AHU). The flow process of the 5-stage purification room is: new return air mixing-chemical filter (NH4+)-chemical filter (SQx)-medium efficiency filter-cooler-supply fan-supply air duct-air supply static pressure box-fan Filter unit (FFU) - clean area - room side lower louver return air inlet - return air duct - new return air mixing. The fresh air is connected to the MAU-1 and 2 fresh air groups shared by other systems.
6 The fresh air required for the clean room outside the CP is treated centrally by two new air blowers (MAU-1, 2), and the fresh air is concentrated and sent to each cycle unit (AHU). The air flow process is: fresh air inlet - coarse filter - medium efficiency filter - pre-heater - surface cooler - heater - clean steam humidification - blower - air supply pipe - each cycle air conditioning unit (AHU).
7 The amount of acid used in the CP chamber, ML chamber and washing chamber is relatively high. The diffuser plate of the high-efficiency filter air supply port in the CP chamber and the ML chamber must be made of stainless steel. The mesh of the FFU in the washing chamber should be made of stainless steel. .
8 It should also be noted that the quality inspection room should adopt black wallboard and black top plate according to the process requirements, and the black return air inlet should be adopted accordingly. The FFU stencil should adopt black stencil.
3. Automatic control of air conditioning in purification system
The new fan unit (MAU-1, 2) uses an inverter fan, which is controlled by a static pressure sensor on the main air supply pipe. An electric regulating valve is arranged on the new air duct connected to each air volume and positive pressure control circulating unit (AHU), and the positive pressure value of each clean room is used to adjust the opening degree of the electric regulating valve to make the positive pressure value of the clean room It does not change with the change of the exhaust air volume of the production equipment. The change of the opening degree of the electric regulating valve causes the static pressure change on the total air supply pipe, and the fan frequency of the AHU-1 and 2 is adjusted according to the set value thereof to achieve the control purpose.
3.1 Temperature and humidity control in the purification workshop
The humidity of the purification workshop is guaranteed by the new fan group MAU-1, 2, controlling the air supply status of the new fan unit, and adjusting the electric actuator and the air cooler and heater of the dry steam humidifier according to the set value of the air supply state. The opening of the electric two-way valve on the water pipe. The dew point temperature DPT is continuously set by the indoor humidity sensitive element HE in the inspection room.
The temperature of the purification workshop is guaranteed by the circulation unit AHU, and the opening degree of the electric two-way valve on the return pipe of the air cooler is adjusted according to the indoor temperature.
3.2 Cooling system control
In the chilled water system, a primary pump is used, and the load control method is used to determine the number of chillers and corresponding pumps and cooling towers. According to the set supply and return water pressure difference, the pressure difference flow bypass valve between the supply and return water mains is automatically controlled.
Guangdong Yuhong Technology Co., Ltd. was established in 2016 by Shenzhen Kebiao, Dongguan Liren and Dongguan Antai, with a registered capital of 100 million yuan. Shenzhen Kebiao Purification Equipment Co., Ltd. was established in 1999. With years of industry accumulation and precipitation, it has developed into a clean room system full industrial chain group company covering three major business segments: material production, equipment production, intelligent control and engineering installation. . In 2018, the group completed a total sales of 700 million yuan.
The group has 1,062 employees, including 113 R&D and engineering technicians, 249 production, management and sales personnel, and 700 engineering installers. In Shenzhen Nanshan Science and Technology Park, 2200m2 of high-quality office buildings were purchased, and Dongguan Tangxia built 13000m2 industrial park. The professional production of industrial clean industry supporting high-end sheet production capacity of 2 million m2, the annual output of clean equipment FFU reached 50,000 units, and established the first wind tunnel laboratory in South China that meets the US MACA ventilation standards. Fully integrate the clean room industry chain system, set up a group research center, and continuously innovate and develop new products and processes of clean systems. Subsidiary Shenzhen Kebiao has the qualifications of the State Construction Department to award the architectural decoration engineering design B, the architectural decoration and decoration engineering contractor grade, the mechanical and electrical installation and the steel structure. It is the overall builder of the large industrial clean room in China. Professional construction of high-grade industrial clean room and air pressure, vacuum, special gas, ultra-pure gas, process exhaust, pure water, process cooling water, wastewater, electricity, weak electricity, monitoring, fire protection, chemical supply and secondary distribution systems engineering. Future Group will focus on the development, production and sales of clean room construction and supporting materials and products in industrial electronics, flat panel display, precision instruments, biomedicine, medical and health industries.
"Care on the ground, professional integrity" is the company's business philosophy and core values that have been upheld for 20 years. The company's vision is to grow into the most competitive clean room system in China.