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A method for removing blue and black spots after diffusion of photovoltaic silicon wafers

A technology for silicon wafers after diffusion, which is applied in the field of solar cleaning technology, can solve the problems of silicon wafer thinning and poor appearance, and achieve the effect of increasing the fragmentation rate

Active Publication Date: 2018-05-11
DONGFANG HUANSHENG PHOTOVOLTAIC (JIANGSU) CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The main purpose of the present invention is to overcome the shortcomings of the above-mentioned existing methods that cause poor appearance and thinning of the silicon wafer, and provide a simple method for removing the diffused blue-black stain and burnt

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] Embodiment 1: A method for removing blue and black spots after the diffusion of photovoltaic silicon wafers. After the photovoltaic silicon wafers have blue and black spots after diffusion, it is further judged whether the blue and black spots have been turned into white spots through etching and coating processes;

[0029] If there are blue and black spots after diffusion, the photovoltaic silicon wafer should be treated as follows:

[0030] s101. Preparation of rework sheet;

[0031] s102. Removing the diffused oxide layer: using a trough-type texturing machine, configuring a hydrofluoric acid solution with a molar concentration of 5% in the first hydrofluoric acid tank, and soaking the reworked sheet for 5 minutes;

[0032] s103, remove blue and black spots: configure the mixed solution of hydrofluoric acid and hydrogen peroxide in the second hydrofluoric acid tank, wherein: the molar concentration of hydrofluoric acid is 15%, and the molar concentration of hydrogen ...

Embodiment 2

[0042] Embodiment 2: A method for removing blue and black spots after diffusion of photovoltaic silicon wafers. After diffusion, photovoltaic silicon wafers have blue and black spots. It is further judged whether the blue and black spots have been turned into white spots through etching and coating processes;

[0043] If there are blue and black spots after diffusion, the photovoltaic silicon wafer should be treated as follows:

[0044] s101. Preparation of rework sheet;

[0045] s102. Removing the diffused oxide layer: using a trough-type texturing machine, configuring a hydrofluoric acid solution with an 8% molar concentration in the first hydrofluoric acid tank, and soaking the reworked sheet for 6 minutes;

[0046] s103, remove blue and black spots: configure the mixed solution of hydrofluoric acid and hydrogen peroxide in the second hydrofluoric acid tank, wherein: the molar concentration of hydrofluoric acid is 20%, and the molar concentration of hydrogen peroxide is 12%...

Embodiment 3

[0056] Embodiment 3: A method for removing blue and black spots after diffusion of photovoltaic silicon wafers. After diffusion, photovoltaic silicon wafers have blue and black spots. It is further judged whether the blue and black spots have been turned into white spots through etching and coating processes;

[0057] If there are blue and black spots after diffusion, the photovoltaic silicon wafer should be treated as follows:

[0058] s101. Preparation of rework sheet;

[0059] s102. Removing the diffused oxide layer: using a tank-type texturing machine, configuring a hydrofluoric acid solution with a molar concentration of 6% in the first hydrofluoric acid tank, and soaking the reworked sheet for 5 minutes;

[0060] s103, remove blue and black spots: configure the mixed solution of hydrofluoric acid and hydrogen peroxide in the second hydrofluoric acid tank, wherein: the molar concentration of hydrofluoric acid is 18%, and the molar concentration of hydrogen peroxide is 11%...

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PUM

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Abstract

The invention discloses a method for removing blue and black spots generated after photovoltaic silicon wafer diffusion. A diffused oxidized layer on the surface of a silicon wafer with the blue and black spots after diffusion or a coated silicon nitride layer on a to-be-reworked silicon wafer with white spots after film coating is removed with hydrofluoric acid, then the cleaned silicon wafer is soaked in a mixed solution containing hydrogen peroxide, hydrofluoric acid and water for a certain period of time, hydrogen peroxide oxidizes the surface of the silicon wafer to form silicon oxide, then silicon oxide reacts with hydrofluoric acid, and a thin layer of silicon on the surface of the silicon wafer is removed after the reaction so that burnt spots can be removed and texture cannot be damaged; the silicon wafer is cleaned with hydrofluoric acid, washed with water and dried and then subjected to diffusion, etching, film coating and printing sintering, and a battery piece is prepared. On the basis of the method, the texturing effect of the first time is not affected, bad texturing is not caused, the thickness of the silicon wafer is hardly changed, and the fragmentation rate is not increased.

Description

technical field [0001] The invention belongs to the technical field of solar cleaning technology, and relates to a new method for removing blue and black spots after diffusion of photovoltaic silicon wafers. Background technique [0002] The blue-black stains that appear on photovoltaic silicon wafers after texturing and diffusion are burnt, and white spots will appear after etching and coating processes, resulting in rework and degradation. The current common practice is to re-texture, but the re-texture is not appropriate. It will cause poor appearance, and the film will become thinner and easily broken. Contents of the invention [0003] The main purpose of the present invention is to overcome the disadvantages of poor appearance and thinning of the silicon wafer caused by the above-mentioned existing method, and provide a simple method for removing the diffused blue-black stain and burnt. [0004] Above-mentioned purpose of the present invention is implemented and rea...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01L31/18H01L21/02
CPCH01L21/02057H01L31/186Y02E10/50Y02P70/50
Inventor 钱明明王丹萍蒋志强陈克彭彪万柳斌
Owner DONGFANG HUANSHENG PHOTOVOLTAIC (JIANGSU) CO LTD