Conveyor furnace, furnaces for the electronic industry.

Conveyor furnace, furnaces for the electronic industry.
	Koyo Thermo Systems Co., Ltd. is represented in Europe by Crystec Technology Trading GmbH
	English deutsch francais Verticals Horizontals RTP Ovens FPD Conveyor Industrial Ceramic LPE Cracker LGO Moldatherm

Furnaces for Solar Cell Production

Firing Furnaces for metallization

The new IR firing furnace was built for the solar cell production. It has got many advantages compared to other furnaces, such as its energy-saving construction. The Al and Ag paste firings require a fast heat-up and cool-down which is one of the reasons why this system saves energy. To reach those fast heat-ups and cool-downs, a fast belt speed is necessary. Unlike the mesh belt conveyor, the walking beam, which is used in this furnace, does not need much energy. Another advantage of this system is the high reliable automatic handling of the wafers. Additionally, the furnace saves space by it's compact design. To reduce the thermal mass on the conveyor material, a "wire" was used instead of a "meshed belt" and to cut off the heat radiation, a "walking beam" was used instead of the "belt conveor". In operation, the mesh belt conveyor furnace needs 62.1 kW and 5300mm of space while the wire conveyor furnace only needs 16.2 kW and 3700mm of space. As a result, the use of energy was reduced by 74% (300,000k W/year) and the need of space was reduced by 30% while the re-alignment of wafers was reduced by 40%.

Exit Side

wire drive mechanism

Specifications

Wafer Size	125mm x 125mm or 155mm x 155mm
Temperature	Max. 2880 sl/hour (4 rows, Tact time; 5 seconds)
Dimension	1650(W)x3700(L)x1550(H) mm

Temperature Profile

Of course you can also use our usal conveyor furnace 47-Mt.

Furnaces for solar cell doping

Koyo Thermo Systems furnace model 206 is designed for this application and for wafers up to 150mm in diameter and fulfills all requirements of this process. The LGO heating elements that are used in this furnace have a very low thermal mass and can reduce therefore the process time. They can also save energy and costs for the doping process. All normal sizes of solar wafers can be processed in this type of furnace. Liquid POCl3 is supplied in a bubbler. Nitrogen passes at a well defined temperature through the liquid and is transporting the dopant. Typical doping temperatures are 800 - 900C.

For higher demands to the homogeneity of the doping profile or to the automation level, vertical furnaces are available. The smallest version of a Koyo Thermo Systems vertical furnace can be very well used especially for the use in research and development of solar cells. The furnace model VF1000 is designed as a mini-batch furnace, has a manual loading and is therefore very flexible regarding sample sizes. This vertical furnace is equipped with a cost saving LGO heating element. The process performance equals the big production versions of vertical furnaces for IC production. The price of this unit is similar to the price of a horizontal tube in a horizontal furnace model 206.

For mass production, Koyo Thermo Systems developed a special vertical furnace, which gives better process results compared to a horizontal one, but still does not increase much the production costs for solar cells. This twin furnace loads 3-4 boats in one vertical tube and has therefore a capacity of 600-800 solar cells. This is the same capacity that you get on a horizontal furnace. Automation is easier to do on a vertical furnace.

Contacting of the photo cells is done by screen printing of metallic thick film pastes. For the backside contacting mostly aluminum paste is used. The finger contacts of the front side consist often of silver. The thick film pastes are then fired in a conveyor furnace. The meshbelt furnace Koyo Thermo Systems model 47-MT has a proven performance for this process. The firing can be done under exclusion of oxygen or even using a reducing atmosphere (forming gas). Automatic loading and unloading is available as an option.

conveyer furnace

Soldering Furnaces

After the testing of the solar cells, they are combined to solar modules in a continuous soldering procedure. This can be done in a Koyo Thermo Systems soldering furnace. Meshbelt transport is used in this soldering furnace. Temperature is 260 °C. The furnace has a downstream gas flow and can be run under nitrogen atmosphere or using a reducing atmosphere (forming gas). Full consideration has been taken on safety mechanisms and for easy handling of the equipment.

soldering furnace

The last step in solar panel production is then the packing between glass plates and testing.

Crystec Technology Trading GmbH will be pleased to further discuss details with you.
Content Page	Are you interested in further information? Please contact us!	Top of Page