Lead-free copper slurry applied to silicon solar battery electrode and preparation method thereof

A silicon solar cell and lead-copper technology, applied in the field of solar cells, can solve the problems of increased production costs, lower application safety factors, lower silver paste prices, etc., and achieve the effects of reducing microcracks, reducing series resistance, and cheap prices

Inactive Publication Date: 2013-09-18
SHENZHEN SENLONT ELECTRONICS
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] Although silver paste has excellent performance in terms of conductivity, solderability, and adhesion, due to the limited amount of silver reserves in the world, it has been over-exploited in recent years, resulting in a sharp increase in the price of precious metal silver in recent years, causing enterprises to produce cost increase
Due to the rapid increase of production enterprises in recent years and fierce market competition, manufacturers keep lowering the price of silver paste, while foreign-funded enterprises take advantage of technological advantages to occupy the high-end market, further reducing profits
Moreover, under the action of DC bias, silver is prone to migration and cause short circuit, which greatly reduces the safety factor of the application

Method used

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  • Lead-free copper slurry applied to silicon solar battery electrode and preparation method thereof
  • Lead-free copper slurry applied to silicon solar battery electrode and preparation method thereof
  • Lead-free copper slurry applied to silicon solar battery electrode and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] Mixed copper powder is prepared using the following three types of copper powder:

[0033] The particle size distribution of spherical copper powder A is 0.5-2μm, the particle size distribution of flake copper powder B is 1-3μm, and the particle size distribution of spherical copper powder C is 4-7μm. The mixed copper powder adopts various mixing ratios. For specific mixing ratios, see Table 1.

[0034] Table-1 Mixing ratio of mixed copper powder

[0035] Mixed Copper Powder No.

Cu1#

Cu2#

Cu3#

Cu4#

[0036] Copper powder A(wt%)

63.6

61.5

66.7

58.3

Copper powder B(wt%)

27.3

30.8

25.0

33.3

Copper powder C(wt%)

9.1

7.7

8.3

8.4

A:B:C mixing ratio

7∶3∶1

8∶4∶1

8∶3∶1

7∶4∶1

[0037] Accurately weigh copper powder A, copper powder B, and copper powder C according to the ratio in Table-1, and mix them in a mixer for...

Embodiment 2

[0040] Highly thixotropic organic vehicles can produce various viscosities according to the proportion of their materials. Different viscosities are suitable for different environments. Organic vehicles with a large proportion of ethyl cellulose and acrylic resin have high viscosity and are suitable for use in summer. On the contrary, the viscosity is small, which is suitable for use in winter. The ratio of each component of the high thixotropic organic carrier related to the present invention is shown in Table-2.

[0041] Table-2 The ratio of each component of the relevant high thixotropic organic vehicle

[0042]

[0043] The preparation process of the organic carrier: accurately weigh various materials according to the above ratio, place them in a stainless steel container, heat them with an oil bath heating device, and heat them at 80°C to 100°C with heat preservation and stirring until the heat preservation and stirring are completed, and then cool to After room temper...

Embodiment 3

[0045] Examples of preparation of lead-free copper paste for silicon solar cell electrodes, the proportions are shown in Table-3 and Table-4.

[0046] Table-3 Examples of preparation of lead-free copper paste for silicon solar cell electrodes

[0047]

[0048]

[0049] Table-4 Examples of preparation of lead-free copper paste for silicon solar cell electrodes (continued table)

[0050]

[0051] Accurately weigh the above-mentioned various materials, carry out strict mixing and grinding, and carry out thorough dispersion and rolling, and finally produce a paste-like liquid with uniform color, and the production is completed.

[0052] Print the finished lead-free copper paste on the silicon solar cell substrate with a 200-325 mesh stainless steel screen, place it flat at room temperature for 10-15 minutes, dry it at 130-160°C for 10-15 minutes, and then place it in a tunnel-type nitrogen-protected conveyor belt furnace Medium sintering, peak temperature 800°C, peak hol...

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Abstract

The present invention provides lead-free copper slurry applied to a silicon solar battery electrode and a preparation method thereof. The lead-free copper slurry is prepared from, by mass, 60% to 85% of mixed copper powder, 1% to 10% of inorganic binder, 10% to 30% of organic binder, 1% to 30% of mixed additive and 5% to 20% of organic solvent. The mixed copper powder comprises copper powder A whose particle diameter distribution is 0.5 to 2 microns, copper powder B whose particle size distribution is 1 to 3 microns and copper powder C whose particle diameter distribution is 4 to 7 microns, wherein the mass ratio of the three kinds of copper powder is 5 to 8:1 to 4:1. The mixed additive is composed of a first additive and a second additive. The first additive is the mixture of one or more than two of a defoaming agent, a silane coupling agent KH-550 and lecithin or span. The second additive is one or more of elements or compounds of transition family or III, IV and V family elements. Ratio restriction on the additive amount of the first additive and the second additive does not exist, and adding is carried out according to the actual situation. The lead-free copper slurry has the advantages of low cost and excellent conductivity, weldability and ohmic contact property, and can be used as universal electrode slurry of electrodes on front and back of a solar battery.

Description

technical field [0001] The application of the present invention relates to a lead-free copper paste for electrodes of silicon solar cells and a preparation method thereof, belonging to the technical field of solar cells. Background technique [0002] Conductive silver paste for solar back electrodes is an important material for solar cells, and it plays the role of conduction and welding in solar cell electrodes. At present, the conductive pastes for solar back electrodes mainly include silver pastes for front electrodes, aluminum pastes for back electrodes, silver aluminum pastes and silver pastes. Because silver-aluminum paste is inferior to silver paste in terms of conductivity and solderability, silver-aluminum paste is gradually being replaced. [0003] Although silver paste has excellent performance in terms of conductivity, solderability, and adhesion, due to the limited amount of silver reserves in the world, it has been over-exploited in recent years, resulting in ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01B1/22H01B1/16H01B13/00H01L31/0224
Inventor 叶志龙张炳胡教军周作文
Owner SHENZHEN SENLONT ELECTRONICS
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