CN108258083A - A kind of preparation process of silicon chip laser doping SE - Google Patents
A kind of preparation process of silicon chip laser doping SE Download PDFInfo
- Publication number
- CN108258083A CN108258083A CN201810052422.1A CN201810052422A CN108258083A CN 108258083 A CN108258083 A CN 108258083A CN 201810052422 A CN201810052422 A CN 201810052422A CN 108258083 A CN108258083 A CN 108258083A
- Authority
- CN
- China
- Prior art keywords
- laser
- silicon chip
- range
- sheet resistance
- ablation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 title claims abstract description 33
- 229910052710 silicon Inorganic materials 0.000 title claims abstract description 33
- 239000010703 silicon Substances 0.000 title claims abstract description 33
- 238000002360 preparation method Methods 0.000 title claims abstract description 7
- 238000000608 laser ablation Methods 0.000 claims abstract description 21
- 238000009792 diffusion process Methods 0.000 claims abstract description 18
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims abstract description 12
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 12
- 239000011574 phosphorus Substances 0.000 claims abstract description 12
- 238000002161 passivation Methods 0.000 claims abstract description 11
- 238000007650 screen-printing Methods 0.000 claims abstract description 8
- 238000002679 ablation Methods 0.000 claims abstract description 4
- 238000005520 cutting process Methods 0.000 claims description 8
- 229910017107 AlOx Inorganic materials 0.000 claims description 6
- 229910004205 SiNX Inorganic materials 0.000 claims description 6
- 229910017604 nitric acid Inorganic materials 0.000 claims description 6
- 241000407429 Maja Species 0.000 claims description 3
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims description 3
- 239000004411 aluminium Substances 0.000 claims description 3
- 229910052782 aluminium Inorganic materials 0.000 claims description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 3
- 238000004140 cleaning Methods 0.000 claims description 3
- 238000000151 deposition Methods 0.000 claims description 3
- 230000008021 deposition Effects 0.000 claims description 3
- 238000003698 laser cutting Methods 0.000 claims description 3
- 239000011259 mixed solution Substances 0.000 claims description 3
- 238000012544 monitoring process Methods 0.000 claims description 3
- 238000000623 plasma-assisted chemical vapour deposition Methods 0.000 claims description 3
- 238000005245 sintering Methods 0.000 claims description 3
- 229910052751 metal Inorganic materials 0.000 claims description 2
- 239000002184 metal Substances 0.000 claims description 2
- 238000000034 method Methods 0.000 abstract description 10
- 238000003892 spreading Methods 0.000 abstract description 2
- 238000005516 engineering process Methods 0.000 description 5
- 239000011521 glass Substances 0.000 description 3
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 2
- 239000010931 gold Substances 0.000 description 2
- 229910052737 gold Inorganic materials 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 101001073212 Arabidopsis thaliana Peroxidase 33 Proteins 0.000 description 1
- 101001123325 Homo sapiens Peroxisome proliferator-activated receptor gamma coactivator 1-beta Proteins 0.000 description 1
- 206010068052 Mosaicism Diseases 0.000 description 1
- 102100028961 Peroxisome proliferator-activated receptor gamma coactivator 1-beta Human genes 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 210000004027 cell Anatomy 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 210000003765 sex chromosome Anatomy 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/26—Bombardment with radiation
- H01L21/263—Bombardment with radiation with high-energy radiation
- H01L21/268—Bombardment with radiation with high-energy radiation using electromagnetic radiation, e.g. laser radiation
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
- H01L31/06—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices characterised by potential barriers
- H01L31/068—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices characterised by potential barriers the potential barriers being only of the PN homojunction type, e.g. bulk silicon PN homojunction solar cells or thin film polycrystalline silicon PN homojunction solar cells
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/18—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
- H01L31/1804—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof comprising only elements of Group IV of the Periodic Table
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/547—Monocrystalline silicon PV cells
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Electromagnetism (AREA)
- General Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- High Energy & Nuclear Physics (AREA)
- Manufacturing & Machinery (AREA)
- Life Sciences & Earth Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Sustainable Development (AREA)
- Optics & Photonics (AREA)
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Toxicology (AREA)
- Physical Vapour Deposition (AREA)
Abstract
The present invention relates to a kind of preparation processes of silicon chip laser doping SE, including being cleaned, spreading successively to silicon chip, laser ablation, wash phosphorus, back of the body passivation, front side of silicon wafer plated film, silicon chip back side plated film, laser opening and silk-screen printing, wherein ablation when laser energy attenuation in the range of 30W~50W, the sheet resistance of ablated area is located in the range of 20~50 Ω.The present invention carries out SE laser ablations in diffusion technique using low square resistance, solves diffusion for high square resistance instability problem, also solves the problems such as diffused surface concentration is inadequate, laser ablation phosphorus source is inadequate and laser ablation easily forms dead and wounded layer.
Description
Technical field
The present invention relates to solar cell preparing technical field more particularly to a kind of systems for silicon chip laser doping SE
Standby technique.
Background technology
Current technical field of solar batteries, high-efficiency battery technology application are constantly progressive, such as the high-efficiency batteries such as PERC,
The transfer efficiency of its battery is constantly being promoted, and in continuous superimposing technique, one of them can be doped using laser,
Prepare selective emission electrode (SE) battery.SE batteries are prepared mainly to have there are two feature：1) metal grid lines and silicon chip contact zone
Domain is heavily doped region, can form good Ohmic contact, improves fill factor；2) light area is lightly doped district, can
To improve the response of shortwave, low surface concentration reduces the compound of few son, so as to improve open-circuit voltage and short circuit current.Swash
Light phosphorosilicate glass doping method is the more SE new technologies of recent research, it mainly by the use of phosphorosilicate glass (PSG) as phosphorus source, is used
The mode of laser ablation forms heavily doped, and the characteristics of technology is that technological process is simple, it is easy to accomplish.Common process is to prepare at present
The phosphorus source of the phosphorosilicate glass on surface by laser ablation in silicon chip is promoted, ultimately forms heavy doping by high square resistance silicon chip again.But
At present this technique there are the problem of have：First, laser ablated region easily forms dead and wounded layer, and it is bad to eventually lead to Ohmic contact, leads
Send a telegraph performance parameter decline；2nd, because surface needs enough phosphorus sources, so very high surface concentration is needed in silicon face, so
Increase the surface concentration after diffusion, but this way easily increases the surface concentration of shallow junction, eventually leads to SE and fails to realize it
Function；3rd, higher sheet resistance, sheet resistance its stability for holding that pressure and electric current can be better but higher are more difficult to control.
Invention content
The technical problem to be solved by the present invention is to：In order to overcome deficiency in the prior art, the present invention provides a kind of silicon chip
The preparation process of laser doping SE, with solve in prior art diffusion for high square resistance unstability, diffused surface concentration not enough,
Laser ablation phosphorus source is inadequate and the problem of laser ablation easily forms dead and wounded layer.
The technical solution adopted by the present invention to solve the technical problems is：A kind of preparation process of silicon chip laser doping SE,
Including being cleaned, spreading successively to silicon chip, laser ablation, wash phosphorus, is back of the body passivation, front side of silicon wafer plated film, silicon chip back side plated film, sharp
Light trepanning and silk-screen printing, the diffusion technique have following steps：
(1), it cleans：By silicon chip in HF/HNO3It is cleaned in mixed solution, removal surface damage layer, cutting stria and gold
Belong to ion；
(2), it spreads：Silicon chip after cleaning is subjected to low pressure DIFFUSION TREATMENT, sheet resistance during diffusion is controlled in 50~80 Ω models
In enclosing；
(3), laser ablation：Silicon chip after diffusion is subjected to front laser ablation, during ablation laser energy attenuation 30W~
In the range of 50W, and the sheet resistance of ablated area is made to reach in the range of 20~50 Ω；
(4), phosphorus is washed：It is cleaned and is etched using HF/HNO3 and KOH, remove the PSG on surface and carry out polished backside,
And the sheet resistance of its heavily doped region is made to control in 50~90 Ω, the sheet resistance in shallow junction region is in the range of 100~150 Ω；
(5), back of the body passivation：Back of the body passivation is carried out using MAIA or ideal, deposition prepares AlOx layer, is then plated with SiNx layer, the back of the body
The overall thickness of AlOx layer and SiNx layer after passivation is controlled between 50nm~300nm；
(6), front plated film：Front plated film is carried out using tubular type PECVD, film thickness monitoring is between 50nm~120nm；
(7), laser grooving：By silicon chip back side carry out laser cutting, wherein laser dig bore dia control 20um~
Between 100um；
(8), silk-screen printing：Silicon chip after cutting is subjected to silk-screen printing sintering back of the body aluminium paste, back electrode and positive electrode.
The beneficial effects of the invention are as follows：The present invention carries out SE laser ablations in diffusion technique using low square resistance, solves
Diffusion for high square resistance instability problem, also solve diffused surface concentration not enough, laser ablation phosphorus source not enough and laser
Ablation easily forms the problems such as dead and wounded layer.
Specific embodiment
A kind of preparation process of silicon chip laser doping SE has following steps：
(1), it cleans：By silicon chip in HF/HNO3It is cleaned in mixed solution, removal surface damage layer, cutting stria and gold
Belong to ion；
(2), it spreads：Silicon chip after cleaning is subjected to low pressure DIFFUSION TREATMENT, sheet resistance during diffusion is controlled in 50~80 Ω models
In enclosing；
(3), laser ablation：Silicon chip after diffusion is subjected to front laser ablation, during ablation laser energy attenuation 30W~
In the range of 50W, and the sheet resistance of ablated area is made to reach in the range of 20~50 Ω；
(4), phosphorus is washed：It is cleaned and is etched using HF/HNO3 and KOH, remove the PSG on surface and carry out polished backside,
And the sheet resistance of its heavily doped region is made to control in 50~90 Ω, the sheet resistance in shallow junction region is in the range of 100~150 Ω；
(5), back of the body passivation：Back of the body passivation is carried out using MAIA or ideal, deposition prepares AlOx layer, is then plated with SiNx layer, the back of the body
The overall thickness of AlOx layer and SiNx layer is controlled after passivation between 50nm~300nm；
(6), front plated film：Using tubular type PECVD carry out front plated film, film thickness monitoring between 50nm~120nm,
To reduce head-on reflection, increase carrier lifetime, improve electric current；
(7), laser grooving：By silicon chip back side carry out laser cutting, wherein laser dig bore dia control 20um~
Between 100um；Since laser is a branch of hot spot, the quality that detects laser is illustrated with spot size, and cutting width is exactly
The diameter of laser facula, length are accordingly converted with die size, and therefore, cutting is defined using bore dia；
(8), silk-screen printing：Silicon chip after cutting is subjected to silk-screen printing sintering back of the body aluminium paste, back electrode and positive electrode.
The present invention carries out SE laser ablations in diffusion technique using low square resistance, and it is unstable for high square resistance to solve diffusion
Sex chromosome mosaicism, also solve diffused surface concentration not enough, laser ablation phosphorus source is inadequate and laser ablation easily forms dead and wounded layer etc. and asks
Topic.
Using above-mentioned desirable embodiment according to the present invention as enlightenment, by above-mentioned description, relevant staff is complete
Various changes and amendments can be carried out without departing from the scope of the technological thought of the present invention' entirely.The technology of this invention
Property range is not limited to the content on specification, it is necessary to determine its technical scope according to right.
Claims (1)
1. a kind of preparation process of silicon chip laser doping SE, it is characterized in that：With following steps：
(1), it cleans：By silicon chip in HF/HNO3Cleaned in mixed solution, removal surface damage layer, cutting stria and metal from
Son；
(2), it spreads：Silicon chip after cleaning is subjected to low pressure DIFFUSION TREATMENT, sheet resistance during diffusion is controlled in the range of 50~80 Ω；
(3), laser ablation：Silicon chip after diffusion is subjected to front laser ablation, laser energy attenuation is in 30W~50W during ablation
In the range of, and the sheet resistance of ablated area is made to reach in the range of 20~50 Ω；
(4), phosphorus is washed：It is cleaned and is etched using HF/HNO3 and KOH, remove the PSG on surface and carry out polished backside, and
The sheet resistance of its heavily doped region is made to control in 50~90 Ω, the sheet resistance in shallow junction region is in the range of 100~150 Ω；
(5), back of the body passivation：Back of the body passivation is carried out using MAIA or ideal, deposition prepares AlOx layer, is then plated with SiNx layer, back of the body passivation
AlOx layer and the overall thickness of SiNx layer afterwards is controlled between 50nm~300nm；
(6), front plated film：Front plated film is carried out using tubular type PECVD, film thickness monitoring is between 50nm~120nm；
(7), laser grooving：Silicon chip back side is subjected to laser cutting, the bore dia that wherein laser is dug is controlled in 20um~100um
Between；
(8), silk-screen printing：Silicon chip after cutting is subjected to silk-screen printing sintering back of the body aluminium paste, back electrode and positive electrode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810052422.1A CN108258083A (en) | 2018-01-19 | 2018-01-19 | A kind of preparation process of silicon chip laser doping SE |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810052422.1A CN108258083A (en) | 2018-01-19 | 2018-01-19 | A kind of preparation process of silicon chip laser doping SE |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN108258083A true CN108258083A (en) | 2018-07-06 |
Family
ID=62741563
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810052422.1A Pending CN108258083A (en) | 2018-01-19 | 2018-01-19 | A kind of preparation process of silicon chip laser doping SE |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108258083A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109873042A (en) * | 2019-03-28 | 2019-06-11 | 深圳市拉普拉斯能源技术有限公司 | One kind being suitable for selection emitter solar battery diffusion technique |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101997060A (en) * | 2010-10-25 | 2011-03-30 | 山东力诺太阳能电力股份有限公司 | Selective diffusion technology for crystalline silicon solar cell |
| CN103151428A (en) * | 2013-03-26 | 2013-06-12 | 浙江晶科能源有限公司 | Method for realizing selective emitter of crystalline silicon solar cell |
-
2018
- 2018-01-19 CN CN201810052422.1A patent/CN108258083A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101997060A (en) * | 2010-10-25 | 2011-03-30 | 山东力诺太阳能电力股份有限公司 | Selective diffusion technology for crystalline silicon solar cell |
| CN103151428A (en) * | 2013-03-26 | 2013-06-12 | 浙江晶科能源有限公司 | Method for realizing selective emitter of crystalline silicon solar cell |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109873042A (en) * | 2019-03-28 | 2019-06-11 | 深圳市拉普拉斯能源技术有限公司 | One kind being suitable for selection emitter solar battery diffusion technique |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR101084067B1 (en) | Solar cell and manufacturing method of the same | |
| CN107394012A (en) | A kind of silicon chip laser doping SE diffusion technique | |
| CN109244194B (en) | Preparation method of low-cost P-type full back electrode crystalline silicon solar cell | |
| US20110189810A1 (en) | Crystalline silicon pv cell with selective emitter produced with low temperature precision etch back and passivation process | |
| CN112259621A (en) | High-efficiency PERC solar cell and preparation method thereof | |
| CN110004472A (en) | The method of contact structures is formed on the solar cell | |
| CN113809205B (en) | Preparation method of solar cell | |
| CN108365022A (en) | The preparation method of the black policrystalline silicon PERC battery structures of selective emitter | |
| CN106784152B (en) | A kind of preparation method of IBC batteries | |
| WO2012135915A1 (en) | Hybrid solar cell contact | |
| Mondon et al. | Plated nickel-copper contacts on c-Si: from microelectronic processing to cost effective silicon solar cell production | |
| CN108963006A (en) | A kind of solar battery and preparation method thereof and cell piece and photovoltaic module based on it | |
| CN102800740A (en) | Manufacturing method of back contact crystalline silicon solar cell | |
| CN101969082B (en) | Process for manufacturing solar cell by twice screen printing and grooving | |
| JP4322082B2 (en) | Manufacturing method of solar cell | |
| CN104362200A (en) | Efficient crystalline silicon solar cell and production method thereof | |
| CN213304149U (en) | High-efficiency PERC solar cell | |
| CN108258083A (en) | A kind of preparation process of silicon chip laser doping SE | |
| CN102800741B (en) | Method for manufacturing back contact crystalline silicon solar battery piece | |
| CN103594532B (en) | A kind of preparation method of N-type crystalline silicon solar cell | |
| CN101937941A (en) | Method for manufacturing crystalline silicon solar cell selective emitter junction | |
| CN102629641B (en) | Preparation method of back contact silicon solar cell | |
| CN109411565B (en) | Solar cell piece, preparation method thereof and photovoltaic module | |
| CN101997060A (en) | Selective diffusion technology for crystalline silicon solar cell | |
| CN103280492A (en) | Method for manufacturing high-sheet-resistance solar cells |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20180706 |
|
| WD01 | Invention patent application deemed withdrawn after publication |