Ribbon Silicon
Although single-crystal silicon technology is well developed,the Czochralski and float-zone processes are complex and expensive (as are the ingot -casing processed discussed under multicrystalline silicon)Another group of crystal-producing processed,however ,goes by the general name of "ribbon growth" .The single crystal may cost less than other processes, because thy form the silicon directly into thin,usable wafers of single-crystal silicon.these methods involve forming .Thin crystalline sheets directly,thus avoiding the slicing step required of cylindrical rods.
One"ribbon growth"technique-edge-defined film-fed growth starts with two crystal seeds that grow and capture a sheet of meterials between them as they are pulled from a source of moltem silicon.A frame entrains a thin sheet of material when drawn from a melt .This technique does not waste much material,but the quality of the material is not as high as Cz and Fz silicon.
Mulyicrystalline Silicon
Multicrystalline Silicon devices are generally less efficient than those of single-crystal silicon,but they can be less expensive to produce .The multicrystalline silicon can be produced in variety of ways.The most popular commercial methods involve a casting process in which molten silicon is directly cast into a mold and allowed to solidify into an ingot.The starting material can be a refined lower-grade silicon,rether that the higher grade semiconductor grade required for single-crystal material .The cooling rate is one factor that determines the final size of crystals in the ingot and the distribution of impurities.The mold is usually square,producing an ingot that can be cut and sliced into square cells that fit more compactly into a pv module .(Round cells have spaces between them in modules ,but square cells fit together better with a minimum of wasted space)
2009年4月10日星期五
Single-crystal Silicon
Single-Crystal Silicon
To creat a silicon in a single-crystal state,we must first melt high-purity silicon.we then cause it to reform or solidify very slowly in contact with a single crystal"seed" the silicon adapts to the pattern of the single-crystal seed as it cools and gradually solidifies.Not surprisingly,because we start form a seed,we say this process is "growing"a new rod (often called a "boule") of single-crystal silicon out of molten silicon.Several different processes can be used to grow a boule of singly-crystal silicon .The most established and dependable processes are the Czochralski (Cz) method and the float-zone(Fz)techique .we also discuss"ribbon-growth" techniques.
Czochralski Silicon
In the Czochralski process, a seed crystal is dipped into a crucible of molten silicon and withdrawn slowly,pulling a cylindrical single crystal as the silicon crystallines on the seed.
Float-zone Silicon
The float-zone process produces purer crystals than the Czochralski method, because they are not contaminated by the crucible used in growing Czochralski crystal .In the float-zone process , a silicon rod is set atop a seed crystal and then field induces an electric field in the rod .Heating and melting the inerface between the rod and the seed.Single-crystal silicon forms at the interface.Growing upward as the coils are slowly raised.
Once the single-crystal rods are produces ,by either the Cz or Fz method, they must be sliced or sawn to form this wafers.Such sawing ,however ,wasters as much as 20% of the valuable silicon as sawdust ,known as"kerf" .The resulting thin wafers are then doped to produce the necessary electric field .They are then treated with a coating to reduce reflection, and coated with electrical contacts to form functioning Pv Cells.
To creat a silicon in a single-crystal state,we must first melt high-purity silicon.we then cause it to reform or solidify very slowly in contact with a single crystal"seed" the silicon adapts to the pattern of the single-crystal seed as it cools and gradually solidifies.Not surprisingly,because we start form a seed,we say this process is "growing"a new rod (often called a "boule") of single-crystal silicon out of molten silicon.Several different processes can be used to grow a boule of singly-crystal silicon .The most established and dependable processes are the Czochralski (Cz) method and the float-zone(Fz)techique .we also discuss"ribbon-growth" techniques.
Czochralski Silicon
In the Czochralski process, a seed crystal is dipped into a crucible of molten silicon and withdrawn slowly,pulling a cylindrical single crystal as the silicon crystallines on the seed.
Float-zone Silicon
The float-zone process produces purer crystals than the Czochralski method, because they are not contaminated by the crucible used in growing Czochralski crystal .In the float-zone process , a silicon rod is set atop a seed crystal and then field induces an electric field in the rod .Heating and melting the inerface between the rod and the seed.Single-crystal silicon forms at the interface.Growing upward as the coils are slowly raised.
Once the single-crystal rods are produces ,by either the Cz or Fz method, they must be sliced or sawn to form this wafers.Such sawing ,however ,wasters as much as 20% of the valuable silicon as sawdust ,known as"kerf" .The resulting thin wafers are then doped to produce the necessary electric field .They are then treated with a coating to reduce reflection, and coated with electrical contacts to form functioning Pv Cells.
Silicon
Silicon used to make some the earliest photovoltaic(PV)decices is still the most popular material for solar cells.Outranked only by oxygen,silicon is also the second-most abundant element in the earth's cust.However ,to be useful as a semiconductor material in solar cells,silicon must be refined to a purity of 99.9999%
In single-crystal silicon ,the molecular structure-which is the arrangement of atoms in the material is uniform,because the entire stucture is grown from the same crystal.This uniformity is ideal for transferring electrons effciently through the material .To make an effective Pv cell, however ,silicon has to be “doped” with other elements to make it n-type and p-type.
Simicrystalline silicon ,in contrast,consist of several smaller crystals or grains ,which introduce boundaries.These boundarias impede the flow of electrons and encourage them to recombine with holes to reduce the power output of the solar cell.However ,semicrystalline silicon is much less expensive to produce than single-crystalline silicon.So researchers are working on other ways to minimize the effects of grain boundaries .
In this section,we will cover silicon solar cell materials in :
Single-crystal silicon
Multicrystalline silicon
Amorphous silicon
In single-crystal silicon ,the molecular structure-which is the arrangement of atoms in the material is uniform,because the entire stucture is grown from the same crystal.This uniformity is ideal for transferring electrons effciently through the material .To make an effective Pv cell, however ,silicon has to be “doped” with other elements to make it n-type and p-type.
Simicrystalline silicon ,in contrast,consist of several smaller crystals or grains ,which introduce boundaries.These boundarias impede the flow of electrons and encourage them to recombine with holes to reduce the power output of the solar cell.However ,semicrystalline silicon is much less expensive to produce than single-crystalline silicon.So researchers are working on other ways to minimize the effects of grain boundaries .
In this section,we will cover silicon solar cell materials in :
Single-crystal silicon
Multicrystalline silicon
Amorphous silicon
DIY Solar Guide
DIY Solar Guide
Welcome to solar shop. Solar cell is high technology product,while it’s easy to install at home. It’s really rewarding after you have installed .It gives us green electricity,bright life,happy future .
What do we need a solar kits for ?
Solar light ,solar security, solar garden light ,solar mobile recharger ….
What are the benefits of installing a solar kit?
Solar electricity is free, energy-saving, money saving, and environmentally friendly!
There are a number of benefits in installing your own solar kit solar kits are cheaper when you install them yourself, we do offer an installation service, if you would prefer us to install your solar panel system for you please call 86-15989515015( Cher zheng )for free advice.
Solar power:
• requires no maintenance (or running costs)
• cuts your electricity bills
• produces electricity in daylight, not just sunlight ,work in cloudy day .
• is kinder to the environment
• is easily integrated with a property
• Increase price of property
• gives you the option of selling surplus electricity
• produces no carbon emissions or pollution
• leaves no waste for future generations
• solar photovoltaic panels are proven technology
• reduces dependence on fossil fuels
• Teach your children the way forward!
• You can also register as an independent energy generator and sell your own electricity to the Gas and Electricity Market Authority.
A photovoltaic (PV) solar energy system installed by Solar Shop will produce many benefits for you and the environment, now and in the future.
Unlike many other Energy providers, once you have installed a PV solar energy system, you will be able to generate electricity for free. The system has no ongoing costs, and because there are no mechanical or moving parts it does not require maintenance.
With a PV solar energy system you will be reducing your dependence on the national grid to fulfil your electricity requirements. The amount of money you will save will depend on how much electricity your household or building uses and how energy-efficient the building and appliances are.
Our photovoltaic panels are among the best available today made up of highly efficient cells that generate electricity even on cloudy days.
Solar systems reduce our requirement for mass installations such as power stations or wind farms and miles of pylons and cables to generate and distribute electricity. By having your own renewable energy source you will be minimising the impact on our landscape and protecting the environment.
Photovoltaic panels generate power without burning any fossil fuels, so by using solar electricity you will be helping to conserve our finite fossil-fuel resources for the current and future generations.
Using sunlight to generate electricity is clean, silent and limitless. It allows you to create power without creating carbon dioxide or other pollutants that contribute to global warming.
As well as being very clean, solar power allows you to generate electricity without leaving harmful waste products that build up to become a problem for us and future generations. Solar power is therefore a proven, reliable and very safe way of producing electricity.
Whether you are designing and constructing a new building or want to retrofit a solar electricity system to an existing building, this type of renewable energy source can be easily incorporated. We can make and design a solar system for you .
As a renewable energy source, photovoltaic panels have been used for some time. They have proved to be reliable and they do work as a way of reducing your reliance on less ‘green’ energy production, and will ultimately save you a large amount of money.
How do Install a solar kit?
Technical helpline 86-15989515015
Email:solarpanelcn@gmail.com
Solar.module@hotmail.com
Cher_zheng@solar-global.cn
MSN: cher_zheng@yahoo.com.cn
Skype: cher_zheng
QQ: 9096785
How does it work?
When light hits the silicon in a solar PV cell, electrical energy is created.
The electricity flows through a cable and is collected at a central point, often located in your roof space.
At this central point the electricity is converted from Direct Current (DC) to Alternating Current (AC) and carries on into your household electricity system.
Contact
Cher Zheng(Ms)
Mobile: 86-15989515015
Email:solarpanelcn@gmail.com
Solar.module@hotmail.com
Cher_zheng@solar-global.cn
MSN: cher_zheng@yahoo.com.cn
Skype: cher_zheng
QQ: 9096785
Welcome to solar shop. Solar cell is high technology product,while it’s easy to install at home. It’s really rewarding after you have installed .It gives us green electricity,bright life,happy future .
What do we need a solar kits for ?
Solar light ,solar security, solar garden light ,solar mobile recharger ….
What are the benefits of installing a solar kit?
Solar electricity is free, energy-saving, money saving, and environmentally friendly!
There are a number of benefits in installing your own solar kit solar kits are cheaper when you install them yourself, we do offer an installation service, if you would prefer us to install your solar panel system for you please call 86-15989515015( Cher zheng )for free advice.
Solar power:
• requires no maintenance (or running costs)
• cuts your electricity bills
• produces electricity in daylight, not just sunlight ,work in cloudy day .
• is kinder to the environment
• is easily integrated with a property
• Increase price of property
• gives you the option of selling surplus electricity
• produces no carbon emissions or pollution
• leaves no waste for future generations
• solar photovoltaic panels are proven technology
• reduces dependence on fossil fuels
• Teach your children the way forward!
• You can also register as an independent energy generator and sell your own electricity to the Gas and Electricity Market Authority.
A photovoltaic (PV) solar energy system installed by Solar Shop will produce many benefits for you and the environment, now and in the future.
Unlike many other Energy providers, once you have installed a PV solar energy system, you will be able to generate electricity for free. The system has no ongoing costs, and because there are no mechanical or moving parts it does not require maintenance.
With a PV solar energy system you will be reducing your dependence on the national grid to fulfil your electricity requirements. The amount of money you will save will depend on how much electricity your household or building uses and how energy-efficient the building and appliances are.
Our photovoltaic panels are among the best available today made up of highly efficient cells that generate electricity even on cloudy days.
Solar systems reduce our requirement for mass installations such as power stations or wind farms and miles of pylons and cables to generate and distribute electricity. By having your own renewable energy source you will be minimising the impact on our landscape and protecting the environment.
Photovoltaic panels generate power without burning any fossil fuels, so by using solar electricity you will be helping to conserve our finite fossil-fuel resources for the current and future generations.
Using sunlight to generate electricity is clean, silent and limitless. It allows you to create power without creating carbon dioxide or other pollutants that contribute to global warming.
As well as being very clean, solar power allows you to generate electricity without leaving harmful waste products that build up to become a problem for us and future generations. Solar power is therefore a proven, reliable and very safe way of producing electricity.
Whether you are designing and constructing a new building or want to retrofit a solar electricity system to an existing building, this type of renewable energy source can be easily incorporated. We can make and design a solar system for you .
As a renewable energy source, photovoltaic panels have been used for some time. They have proved to be reliable and they do work as a way of reducing your reliance on less ‘green’ energy production, and will ultimately save you a large amount of money.
How do Install a solar kit?
Technical helpline 86-15989515015
Email:solarpanelcn@gmail.com
Solar.module@hotmail.com
Cher_zheng@solar-global.cn
MSN: cher_zheng@yahoo.com.cn
Skype: cher_zheng
QQ: 9096785
How does it work?
When light hits the silicon in a solar PV cell, electrical energy is created.
The electricity flows through a cable and is collected at a central point, often located in your roof space.
At this central point the electricity is converted from Direct Current (DC) to Alternating Current (AC) and carries on into your household electricity system.
Contact
Cher Zheng(Ms)
Mobile: 86-15989515015
Email:solarpanelcn@gmail.com
Solar.module@hotmail.com
Cher_zheng@solar-global.cn
MSN: cher_zheng@yahoo.com.cn
Skype: cher_zheng
QQ: 9096785
Home page
Welcome to Solar Shop we are the best priced solar manufactory in China .we have our PECVD and laser processes,don’t worry about supply shortages ,customize different specification for you ,with solar home system, outdoor light, emergency light, mosquito zappers ect.Can always have fresh selection to choose ,contact us today .
contact : Cher zheng
Thanks & Best regards
Cher Zheng(Ms)
MB:86-15989515015
msn:cher_zheng@yahoo.com.cn
yahoo: cher_zheng@yahoo.com.cn
hotmail:solar.module@hotmail.com
skype: cher_zheng
Google talk: solarpanelcn
www.solarglobal.blogspot.com
Shenzhen Global Solar Energy
contact : Cher zheng
Thanks & Best regards
Cher Zheng(Ms)
MB:86-15989515015
msn:cher_zheng@yahoo.com.cn
yahoo: cher_zheng@yahoo.com.cn
hotmail:solar.module@hotmail.com
skype: cher_zheng
Google talk: solarpanelcn
www.solarglobal.blogspot.com
Shenzhen Global Solar Energy
2009年3月26日星期四
非晶硅太阳能电池生产技术
非晶硅太阳能电池生产技术
非晶硅太阳电池的生产主要采用APCVD、PECVD、激光、真空、薄膜、光刻、磁控溅射等高新技术。
整套生产线只要包括：超声清洗设备、非晶硅电池薄膜沉积系统-PECVD设备、磁控溅射镀Al膜设备、激光刻划机、电池测试系统、烘烤系统和其他辅助设备。
非晶硅层叠太阳电池的生产制造工艺流程为：
二氧化锡（SnO2）透明导电玻璃→激光刻划二氧化锡→超声清洗、干燥→预热→PECVD系统沉积非晶硅薄膜（pin/pin）→冷却→激光刻划非晶硅层－溅射镀铝→激光刻铝→测试1→老化→测试2→封装→成品测试→分类包装
主要工序介绍如下：
（1）激光切割二氧化锡，用三光束激光（波长1064nm）系统将二氧化锡切割成相互独立的部分，目的是将整板分为若干块，作为若干个单体电池的电极。
（2）基片清洗，去离子水双面冲洗基片，净化热风充分吹干基片。基片应该是完全干燥的、没有任何碎屑、油污和其他残留物。
3）非晶硅薄膜沉积，非晶硅薄膜沉积是电池组件制造过程中的关键工序之一。该工序设备最复杂，其操作程序直接关系组件的质量。内容包括：基片装盒、基片预热、非晶硅沉积、电池片冷却。预热炉烘烤温度可调，PID温控调节，将装有玻璃的反应盒推进炉中加热，用于沉积PIN薄膜前预热玻璃基板，预热后的基板进入PECVD系统，根据生产工艺要求控制沉积炉真空度，沉积温度，各种工作气体流量，沉积压力，沉积时间，射频电源放电功率等工艺参数，确保非晶硅薄膜沉积质量，提高电池组件合格率、实现工艺重复性。
（4）激光刻划非晶硅层，根据生产预定的线宽以及与SnO2切割线的线间距，用绿激光（波长532nm）将a-Si膜刻划穿，目的是让背电极（金属铝）通过与前电极（SnO2导电膜）相联接，实现整板由若干个单体电池内部串联而成。
（5）铝背电极溅射与激光切铝
铝溅射的目的是形成电池组件的背电极。溅射工艺采用基片移动、平面磁控铝溅射技术，确保背电极的可靠性。该系统包括进片室、溅射室和出片室。采用计算机自动控制。
本生产线设备制造和整个工艺过程中过程中，PECVD沉积系统和PIN薄膜沉积工艺为核心技术，PECVD即等离子体化学气象沉积设备，一次沉积玻璃基板48片，采用不锈钢真空室，配套真空系统；所有真空阀门电器自动操作，计算机系统控制，屏幕显示系统重要器件状态；成套工作气路控制系统，配有害气体探测及报警、废气处理装置；设备配置射频电源；真空室加热PID温控。
另外镀铝磁控溅射设备和Al背电极沉积技术为核心技术，大面积连续磁控溅射设备，整个生产过程由程序自动控制完成；不锈钢真空室，由进片室、溅射室、出片室和过渡室组成；特有的设计结构便于维护和清洁；沉积室采用分子泵系统；控制系统采用计算机控制；操作可采用自动及手动。
以上设备和工艺条件下生产的635*1245mm大面积、双结非晶硅电池组件全面积初始转换效率可达到6.5%；有效面积初始转换效率为7%；按照非晶硅双结电池组件15%计算光致衰退，则全面积稳定转换效率为5.5%；有效面积稳定转换效率为6%。
--------------------by Lijuan Liu
非晶硅太阳电池的生产主要采用APCVD、PECVD、激光、真空、薄膜、光刻、磁控溅射等高新技术。
整套生产线只要包括：超声清洗设备、非晶硅电池薄膜沉积系统-PECVD设备、磁控溅射镀Al膜设备、激光刻划机、电池测试系统、烘烤系统和其他辅助设备。
非晶硅层叠太阳电池的生产制造工艺流程为：
二氧化锡（SnO2）透明导电玻璃→激光刻划二氧化锡→超声清洗、干燥→预热→PECVD系统沉积非晶硅薄膜（pin/pin）→冷却→激光刻划非晶硅层－溅射镀铝→激光刻铝→测试1→老化→测试2→封装→成品测试→分类包装
主要工序介绍如下：
（1）激光切割二氧化锡，用三光束激光（波长1064nm）系统将二氧化锡切割成相互独立的部分，目的是将整板分为若干块，作为若干个单体电池的电极。
（2）基片清洗，去离子水双面冲洗基片，净化热风充分吹干基片。基片应该是完全干燥的、没有任何碎屑、油污和其他残留物。
3）非晶硅薄膜沉积，非晶硅薄膜沉积是电池组件制造过程中的关键工序之一。该工序设备最复杂，其操作程序直接关系组件的质量。内容包括：基片装盒、基片预热、非晶硅沉积、电池片冷却。预热炉烘烤温度可调，PID温控调节，将装有玻璃的反应盒推进炉中加热，用于沉积PIN薄膜前预热玻璃基板，预热后的基板进入PECVD系统，根据生产工艺要求控制沉积炉真空度，沉积温度，各种工作气体流量，沉积压力，沉积时间，射频电源放电功率等工艺参数，确保非晶硅薄膜沉积质量，提高电池组件合格率、实现工艺重复性。
（4）激光刻划非晶硅层，根据生产预定的线宽以及与SnO2切割线的线间距，用绿激光（波长532nm）将a-Si膜刻划穿，目的是让背电极（金属铝）通过与前电极（SnO2导电膜）相联接，实现整板由若干个单体电池内部串联而成。
（5）铝背电极溅射与激光切铝
铝溅射的目的是形成电池组件的背电极。溅射工艺采用基片移动、平面磁控铝溅射技术，确保背电极的可靠性。该系统包括进片室、溅射室和出片室。采用计算机自动控制。
本生产线设备制造和整个工艺过程中过程中，PECVD沉积系统和PIN薄膜沉积工艺为核心技术，PECVD即等离子体化学气象沉积设备，一次沉积玻璃基板48片，采用不锈钢真空室，配套真空系统；所有真空阀门电器自动操作，计算机系统控制，屏幕显示系统重要器件状态；成套工作气路控制系统，配有害气体探测及报警、废气处理装置；设备配置射频电源；真空室加热PID温控。
另外镀铝磁控溅射设备和Al背电极沉积技术为核心技术，大面积连续磁控溅射设备，整个生产过程由程序自动控制完成；不锈钢真空室，由进片室、溅射室、出片室和过渡室组成；特有的设计结构便于维护和清洁；沉积室采用分子泵系统；控制系统采用计算机控制；操作可采用自动及手动。
以上设备和工艺条件下生产的635*1245mm大面积、双结非晶硅电池组件全面积初始转换效率可达到6.5%；有效面积初始转换效率为7%；按照非晶硅双结电池组件15%计算光致衰退，则全面积稳定转换效率为5.5%；有效面积稳定转换效率为6%。
--------------------by Lijuan Liu
非晶硅薄膜电池产业化的优势
目前常见的硅片太阳电池相比，非晶硅薄膜电池产业化的优势为：
（1）制造成本低：①衬底廉价；②非晶硅光吸收系数比晶体硅大一个数量级，电池厚度只需1μｍ左右，约为晶体硅电池的1/200，可节省大量硅材料；③电池的pin结在200℃左右的温度下制造，比晶体硅电池的800℃～1000℃的高温低得多，能源消耗小，能源消耗的回收期短；④制造工艺简单，能够批量生产，可采用集成技术在电池制备过程中一次完成组件，易于大规模生产；⑤电池的单片面积可做到0.7～5.7㎡，组装方便。以上优点可使每瓦太阳电池成本从2.5美元降至1.2美元。（2）发电量多，对于同功率的太阳电池阵列，非晶硅电池的发电量比单晶硅、多晶硅电池发电要多约8%-10%；低光性能好，非晶硅光电产品在光度很弱的情况下依旧运行很好，而其它光伏产品的效率则明显降低。（3）非晶硅薄膜光电的一大优势为薄膜光伏电池模板易在两片玻璃之间进行密封。薄膜光电模板的质量和寿命不仅可与晶硅模板相媲美（一般寿命为25年），而且玻璃密封使得他们更耐用，而且可防止天气变化引起的递减。非晶硅薄膜光电模板的质量和寿命都可超过晶体硅。（4）这种高科技新产品可与建筑物屋顶、墙体材料如玻璃幕墙融为一体(BIPV，光伏建筑一体化)，既可并网发电又能节约建筑材料、美化环境。（5）耐侯性好，在温度增高的情况下丧失的效率较少。晶体硅高温下的发电性能明显不如非晶硅光伏电池稳定。（6）品种多，用途广，对大量仪器的高适配性。非晶硅太阳电池易于实现集成化，器件功率、输出电压、输出电流都可自由设计制造，可以较方便地制作出适合不同需求的多品种产品。
-------------------------------from LIJUAN lIU
Transalte by Cher zheng :
（1）制造成本低：①衬底廉价；②非晶硅光吸收系数比晶体硅大一个数量级，电池厚度只需1μｍ左右，约为晶体硅电池的1/200，可节省大量硅材料；③电池的pin结在200℃左右的温度下制造，比晶体硅电池的800℃～1000℃的高温低得多，能源消耗小，能源消耗的回收期短；④制造工艺简单，能够批量生产，可采用集成技术在电池制备过程中一次完成组件，易于大规模生产；⑤电池的单片面积可做到0.7～5.7㎡，组装方便。以上优点可使每瓦太阳电池成本从2.5美元降至1.2美元。（2）发电量多，对于同功率的太阳电池阵列，非晶硅电池的发电量比单晶硅、多晶硅电池发电要多约8%-10%；低光性能好，非晶硅光电产品在光度很弱的情况下依旧运行很好，而其它光伏产品的效率则明显降低。（3）非晶硅薄膜光电的一大优势为薄膜光伏电池模板易在两片玻璃之间进行密封。薄膜光电模板的质量和寿命不仅可与晶硅模板相媲美（一般寿命为25年），而且玻璃密封使得他们更耐用，而且可防止天气变化引起的递减。非晶硅薄膜光电模板的质量和寿命都可超过晶体硅。（4）这种高科技新产品可与建筑物屋顶、墙体材料如玻璃幕墙融为一体(BIPV，光伏建筑一体化)，既可并网发电又能节约建筑材料、美化环境。（5）耐侯性好，在温度增高的情况下丧失的效率较少。晶体硅高温下的发电性能明显不如非晶硅光伏电池稳定。（6）品种多，用途广，对大量仪器的高适配性。非晶硅太阳电池易于实现集成化，器件功率、输出电压、输出电流都可自由设计制造，可以较方便地制作出适合不同需求的多品种产品。
-------------------------------from LIJUAN lIU
Transalte by Cher zheng :
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