CN112724878A - Nano silver powder conductive adhesive with good conductivity - Google Patents

Nano silver powder conductive adhesive with good conductivity Download PDF

Info

Publication number
CN112724878A
CN112724878A CN201910973596.6A CN201910973596A CN112724878A CN 112724878 A CN112724878 A CN 112724878A CN 201910973596 A CN201910973596 A CN 201910973596A CN 112724878 A CN112724878 A CN 112724878A
Authority
CN
China
Prior art keywords
parts
silver powder
powder conductive
nano silver
conductive adhesive
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.)
Withdrawn
Application number
CN201910973596.6A
Other languages
Chinese (zh)
Inventor
江仁燕
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to CN201910973596.6A priority Critical patent/CN112724878A/en
Publication of CN112724878A publication Critical patent/CN112724878A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J9/00—Adhesives characterised by their physical nature or the effects produced, e.g. glue sticks
    • C09J9/02—Electrically-conducting adhesives
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
    • C09J11/02—Non-macromolecular additives
    • C09J11/06—Non-macromolecular additives organic
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J163/00—Adhesives based on epoxy resins; Adhesives based on derivatives of epoxy resins
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/02—Elements
    • C08K3/08—Metals
    • C08K2003/0806—Silver
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K2201/00—Specific properties of additives
    • C08K2201/001—Conductive additives
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K2201/00—Specific properties of additives
    • C08K2201/002—Physical properties
    • C08K2201/003—Additives being defined by their diameter
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K2201/00—Specific properties of additives
    • C08K2201/011—Nanostructured additives
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K2201/00—Specific properties of additives
    • C08K2201/014—Additives containing two or more different additives of the same subgroup in C08K

Abstract

The invention relates to the technical field of composite conductive adhesives, and discloses a nano silver powder conductive adhesive with good conductivity, which comprises the following raw materials in parts by weight: 100 parts of epoxy resin E-51 matrix resin, 98 parts of curing agent, 0.67 part of curing accelerator, composite self-sintering surfactant consisting of 1-3 parts of benzyltriethylammonium chloride and 1-4 parts of tetrabutylammonium hydrogen sulfate, 140-165 parts of nano silver powder conductive filler, 1 part of malonic acid conductive accelerator, 2 parts of silane coupling agent, 1 part of antioxidant and 2 parts of defoaming agent. The invention solves the technical problem that the existing nano silver powder conductive adhesive has poor conductive performance while meeting high-density connection.

Description

Nano silver powder conductive adhesive with good conductivity
Technical Field
The invention relates to the technical field of composite conductive adhesives, in particular to a nano silver powder conductive adhesive with good conductivity.
Background
With the development of microelectronic assembly industry towards high density and high integration and stricter environmental legislation, it is imperative that conductive adhesives replace soldering lead solder in the field of microelectronic assembly. The conductive adhesive is divided into two types, one is an intrinsic conductive adhesive, which is a conjugated polymer with a molecular structure having a conductive function and mostly consists of a polyphenylene and polyacetylene-based compound, the other is a composite conductive adhesive with conductive particles filled in the polymer, and the composite conductive adhesive generally consists of matrix resin, a curing agent, a curing accelerator, a diluent, conductive particles and other additives.
At present, research is carried out on the nano metal particles as the conductive adhesive filler so as to meet the requirement of high-density connection. Research shows that the addition of the silver nanoparticles can reduce the percolation threshold of the conductive adhesive, however, the conductive adhesive doped with the silver nanoparticles generally shows poor conductivity or even non-conductivity due to the increase of contact points between the silver nanoparticles, because the total resistance is composed of three parts, namely intrinsic resistance of conductive particles, resistance between the conductive particles and a substrate when the conductive adhesive is used for connection, and when the silver nanoparticles are used as conductive fillers, the contact points are more than when the silver nanoparticles are used, and the contact resistance between the conductive particles is larger.
Disclosure of Invention
Technical problem to be solved
Aiming at the defects of the prior art, the invention provides the nano silver powder conductive adhesive with good conductivity, so as to solve the technical problem that the existing nano silver powder conductive adhesive has poor conductivity while meeting high-density connection.
(II) technical scheme
In order to achieve the purpose, the invention provides the following technical scheme:
the nanometer silver powder conductive adhesive with good conductivity comprises the following raw materials in parts by weight: 100 parts of epoxy resin E-51 matrix resin, 98 parts of curing agent, 0.67 part of curing accelerator, composite self-sintering surfactant consisting of 1-3 parts of benzyltriethylammonium chloride and 1-4 parts of tetrabutylammonium hydrogen sulfate, 140-165 parts of nano silver powder conductive filler, 1 part of malonic acid conductive accelerator, 2 parts of silane coupling agent, 1 part of antioxidant and 2 parts of defoaming agent.
Further, the average grain diameter of the silver powder conductive filler is less than or equal to 100 nm.
Further, the curing agent is methyl hexahydrophthalic anhydride (MeHHPA), and the curing accelerator is 2-ethyl-4-methylimidazole (2E4 MZ).
Further, the nano silver powder conductive adhesive comprises the following raw materials in parts by weight: 100g of epoxy resin E-51 matrix resin, 98g of methylhexahydrophthalic anhydride (MeHHPA) curing agent, 0.67g of 2-ethyl-4-methylimidazole (2E4MZ) curing accelerator, 3g of benzyl triethyl ammonium chloride and 1g of tetrabutylammonium hydrogen sulfate composite self-sintering surfactant, 165g of silver powder conductive filler with the average particle size of less than or equal to 100nm, 1g of malonic acid conductive accelerator, 2g of r-aminopropyl triethoxysilane coupling agent, 1g of phenyl hydroquinone antioxidant and 2g of compound silicone defoamer.
(III) advantageous technical effects
Compared with the prior art, the invention has the following beneficial technical effects:
adding a composite self-sintering surfactant consisting of 1-3 parts of benzyltriethylammonium chloride and 1-4 parts of tetrabutylammonium hydrogen sulfate, 140-165 parts of nano silver powder conductive filler and 1 part of malonic acid conductive promoter into a resin matrix, and preparing the nano silver powder conductive adhesive by adopting a grinding and mixing method;
the composite self-sintering surfactant enables the nano silver powder to show obvious sintering behavior in the curing process of the conductive adhesive, so that the interface performance among fillers and between the fillers and a resin matrix is improved, and the contact resistance among conductive particles is reduced;
the volume resistivity of the nano silver powder conductive adhesive prepared by the invention is 4.08 multiplied by 10-4～4.32×10-4Omega cm, conductivity of 2.21X 103～2.53×103S·cm-1；
The volume resistivity of the nano silver powder conductive adhesive prepared by the comparative example is 1.54 multiplied by 10-2Omega cm, conductivity 5.73X 10S cm-1Compared with the prior art, the technical effect of remarkably improving the conductivity of the nano silver powder conductive adhesive is achieved;
therefore, the technical problem that the existing nano silver powder conductive adhesive has poor conductivity while meeting high-density connection is solved.
Detailed Description
The following raw materials were used:
epoxy resin E-51, the epoxy equivalent is 185-208 g/eq, the epoxy value is 0.48-0.54 eq/100g, and the viscosity is less than or equal to 2.5 Pa.s (at 25 ℃);
methylhexahydrophthalic anhydride (MeHHPA), acid number 657.32, free acid 0.18%, iodine number 0.87, freezing point-15 ℃.
The first embodiment is as follows:
the nano silver powder conductive adhesive comprises the following raw materials in parts by weight: 100g of epoxy resin E-51 matrix resin, 98g of methylhexahydrophthalic anhydride (MeHHPA) curing agent, 0.67g of 2-ethyl-4-methylimidazole (2E4MZ) curing accelerator, a composite self-sintering surfactant consisting of 3g of benzyltriethylammonium chloride and 2g of tetrabutylammonium hydrogen sulfate, 140g of silver powder conductive filler with the average particle size of less than or equal to 100nm, 1g of malonic acid conductive accelerator, 2g of r-aminopropyltriethoxysilane coupling agent, 1g of phenylhydroquinone antioxidant and 2g of compound silicone defoamer;
the preparation method of the nano silver powder conductive adhesive comprises the following steps:
the method comprises the following steps: weighing 100g of epoxy resin E-51 matrix resin, 98g of methylhexahydrophthalic anhydride (MeHHPA) curing agent and 0.67g of 2-ethyl-4-methylimidazole (2E4MZ) curing accelerator in sequence into a beaker, stirring for 10min to uniformly mix the components of the matrix, vacuumizing for 30min to remove bubbles, and preparing to obtain a resin matrix;
step two: transferring the prepared resin matrix into an agate mortar, adding a composite self-sintering surfactant consisting of 3g of benzyltriethylammonium chloride and 2g of tetrabutylammonium hydrogen sulfate into the agate mortar, and grinding the mixture to be uniform;
step three: adding 40g of silver powder conductive filler into an agate mortar for the first time, and grinding for 5 min; then adding 1g of malonic acid conduction promoter and 2g of r-aminopropyltriethoxysilane coupling agent, and grinding until the mixture is uniform;
step four: adding 100g of silver powder conductive filler into the agate mortar for the second time, and grinding for 15 min; then adding 1g of phenyl hydroquinone antioxidant and 2g of organic silicon compound defoaming agent, and grinding for 15min to prepare the nano silver powder conductive adhesive.
Example two:
the nano silver powder conductive adhesive comprises the following raw materials in parts by weight: 100g of epoxy resin E-51 matrix resin, 98g of methylhexahydrophthalic anhydride (MeHHPA) curing agent, 0.67g of 2-ethyl-4-methylimidazole (2E4MZ) curing accelerator, a composite self-sintering surfactant consisting of 1g of benzyltriethylammonium chloride and 4g of tetrabutylammonium hydrogen sulfate, 150g of silver powder conductive filler with the average particle size of less than or equal to 100nm, 1g of malonic acid conductive accelerator, 2g of r-aminopropyltriethoxysilane coupling agent, 1g of phenylhydroquinone antioxidant and 2g of compound silicone defoamer;
the preparation method of the nano silver powder conductive adhesive comprises the following steps:
the method comprises the following steps: weighing 100g of epoxy resin E-51 matrix resin, 98g of methylhexahydrophthalic anhydride (MeHHPA) curing agent and 0.67g of 2-ethyl-4-methylimidazole (2E4MZ) curing accelerator in sequence into a beaker, stirring for 10min to uniformly mix the components of the matrix, vacuumizing for 30min to remove bubbles, and preparing to obtain a resin matrix;
step two: transferring the prepared resin matrix into an agate mortar, adding a composite self-sintering surfactant consisting of 1g of benzyltriethylammonium chloride and 4g of tetrabutylammonium hydrogen sulfate into the agate mortar, and grinding the mixture to be uniform;
step three: adding 50g of silver powder conductive filler into an agate mortar for the first time, and grinding for 5 min; then adding 1g of malonic acid conduction promoter and 2g of r-aminopropyltriethoxysilane coupling agent, and grinding until the mixture is uniform;
step four: adding 100g of silver powder conductive filler into the agate mortar for the second time, and grinding for 15 min; then adding 1g of phenyl hydroquinone antioxidant and 2g of organic silicon compound defoaming agent, and grinding for 15min to prepare the nano silver powder conductive adhesive.
Example three:
the nano silver powder conductive adhesive comprises the following raw materials in parts by weight: 100g of epoxy resin E-51 matrix resin, 98g of methylhexahydrophthalic anhydride (MeHHPA) curing agent, 0.67g of 2-ethyl-4-methylimidazole (2E4MZ) curing accelerator, a composite self-sintering surfactant consisting of 3g of benzyltriethylammonium chloride and 1g of tetrabutylammonium hydrogen sulfate, 165g of silver powder conductive filler with the average particle size of less than or equal to 100nm, 1g of malonic acid conductive accelerator, 2g of r-aminopropyltriethoxysilane coupling agent, 1g of phenylhydroquinone antioxidant and 2g of compound silicone defoamer;
the preparation method of the nano silver powder conductive adhesive comprises the following steps:
the method comprises the following steps: weighing 100g of epoxy resin E-51 matrix resin, 98g of methylhexahydrophthalic anhydride (MeHHPA) curing agent and 0.67g of 2-ethyl-4-methylimidazole (2E4MZ) curing accelerator in sequence into a beaker, stirring for 10min to uniformly mix the components of the matrix, vacuumizing for 30min to remove bubbles, and preparing to obtain a resin matrix;
step two: transferring the prepared resin matrix into an agate mortar, adding a composite self-sintering surfactant consisting of 3g of benzyltriethylammonium chloride and 1g of tetrabutylammonium hydrogen sulfate into the agate mortar, and grinding the mixture to be uniform;
step three: adding 65g of silver powder conductive filler into an agate mortar for the first time, and grinding for 5 min; then adding 1g of malonic acid conduction promoter and 2g of r-aminopropyltriethoxysilane coupling agent, and grinding until the mixture is uniform;
step four: adding 100g of silver powder conductive filler into the agate mortar for the second time, and grinding for 15 min; then adding 1g of phenyl hydroquinone antioxidant and 2g of organic silicon compound defoaming agent, and grinding for 15min to prepare the nano silver powder conductive adhesive.
Comparative example:
the nano silver powder conductive adhesive comprises the following raw materials in parts by weight: 100g of epoxy resin E-51 matrix resin, 98g of methylhexahydrophthalic anhydride (MeHHPA) curing agent, 0.67g of 2-ethyl-4-methylimidazole (2E4MZ) curing accelerator, 140g of silver powder conductive filler with the average particle size of less than or equal to 100nm, 2g of r-aminopropyltriethoxysilane coupling agent, 1g of phenylhydroquinone antioxidant and 2g of organosilicon compound defoaming agent;
the preparation method of the nano silver powder conductive adhesive comprises the following steps:
the method comprises the following steps: weighing 100g of epoxy resin E-51 matrix resin, 98g of methylhexahydrophthalic anhydride (MeHHPA) curing agent and 0.67g of 2-ethyl-4-methylimidazole (2E4MZ) curing accelerator in sequence into a beaker, stirring for 10min to uniformly mix the components of the matrix, vacuumizing for 30min to remove bubbles, and preparing to obtain a resin matrix;
step two: transferring the prepared resin matrix into an agate mortar, and grinding the resin matrix to be uniform;
step three: adding 40g of silver powder conductive filler into an agate mortar for the first time, and grinding for 5 min; then 2g of r-aminopropyl triethoxysilane coupling agent is added, and the mixture is ground to be uniform;
step four: adding 100g of silver powder conductive filler into the agate mortar for the second time, and grinding for 15 min; then adding 1g of phenyl hydroquinone antioxidant and 2g of organic silicon compound defoaming agent, and grinding for 15min to prepare the nano silver powder conductive adhesive.
And (3) performance testing:
the nano silver powder conductive adhesives prepared in the above examples and comparative examples were subjected to performance tests, and the test results are shown in table 1.
TABLE 1
Figure BDA0002232911350000061
Figure BDA0002232911350000071

Claims (4)

1. The nanometer silver powder conductive adhesive with good conductivity is characterized by comprising the following raw materials in parts by weight: 100 parts of epoxy resin E-51 matrix resin, 98 parts of curing agent, 0.67 part of curing accelerator, composite self-sintering surfactant consisting of 1-3 parts of benzyltriethylammonium chloride and 1-4 parts of tetrabutylammonium hydrogen sulfate, 140-165 parts of nano silver powder conductive filler, 1 part of malonic acid conductive accelerator, 2 parts of silane coupling agent, 1 part of antioxidant and 2 parts of defoaming agent.
2. The silver powder conductive paste according to claim 1, wherein the silver powder conductive filler has an average particle size of 100nm or less.
3. The silver nanoparticle powder conductive paste according to claim 2, wherein the curing agent is methylhexahydrophthalic anhydride (MeHHPA) and the curing accelerator is 2-ethyl-4-methylimidazole (2E4 MZ).
4. The nano silver powder conductive adhesive according to claim 3, comprising the following raw materials in parts by weight: 100g of epoxy resin E-51 matrix resin, 98g of methylhexahydrophthalic anhydride (MeHHPA) curing agent, 0.67g of 2-ethyl-4-methylimidazole (2E4MZ) curing accelerator, 3g of benzyl triethyl ammonium chloride and 1g of tetrabutylammonium hydrogen sulfate composite self-sintering surfactant, 165g of silver powder conductive filler with the average particle size of less than or equal to 100nm, 1g of malonic acid conductive accelerator, 2g of r-aminopropyl triethoxysilane coupling agent, 1g of phenyl hydroquinone antioxidant and 2g of compound silicone defoamer.
CN201910973596.6A 2019-10-14 2019-10-14 Nano silver powder conductive adhesive with good conductivity Withdrawn CN112724878A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201910973596.6A CN112724878A (en) 2019-10-14 2019-10-14 Nano silver powder conductive adhesive with good conductivity

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201910973596.6A CN112724878A (en) 2019-10-14 2019-10-14 Nano silver powder conductive adhesive with good conductivity

Publications (1)

Publication Number Publication Date
CN112724878A true CN112724878A (en) 2021-04-30

Family

ID=75588689

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201910973596.6A Withdrawn CN112724878A (en) 2019-10-14 2019-10-14 Nano silver powder conductive adhesive with good conductivity

Country Status (1)

Country Link
CN (1) CN112724878A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114262583A (en) * 2021-12-21 2022-04-01 深圳市中金岭南有色金属股份有限公司科学技术开发院 Silver conductive adhesive for high-conductivity interconnection die bonding of high-power LED chips and components
US20230212409A1 (en) * 2021-12-31 2023-07-06 Korea Institute Of Science And Technology Conductive polymer adhesive and method of preparing the same

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114262583A (en) * 2021-12-21 2022-04-01 深圳市中金岭南有色金属股份有限公司科学技术开发院 Silver conductive adhesive for high-conductivity interconnection die bonding of high-power LED chips and components
CN114262583B (en) * 2021-12-21 2022-12-20 深圳市中金岭南有色金属股份有限公司科学技术开发院 Silver conductive adhesive for high-conductivity interconnection die bonding of high-power LED chips and components
US20230212409A1 (en) * 2021-12-31 2023-07-06 Korea Institute Of Science And Technology Conductive polymer adhesive and method of preparing the same

Similar Documents

Publication Publication Date Title
CN106753133B (en) Conductive silver adhesive and preparation method and application thereof
CN109135612B (en) Low-melting-point metal micro-nano powder conductive adhesive and preparation method thereof
JP2010109334A (en) Conductive ink composition and solar cell module formed using the same
WO2018006503A1 (en) Silver salt-doped conductive silver adhesive, and preparation method and use thereof
CN112724878A (en) Nano silver powder conductive adhesive with good conductivity
CN108264879A (en) A kind of low-temperature fast-curing two-component conducting resinl
US10332649B2 (en) Conductive paste
CN100373504C (en) Nano silver wire added conductive composite material, and preparation method
CN114456736B (en) Modified silver-coated copper conductive powder epoxy conductive adhesive and preparation method thereof
CN114276766A (en) Nano-silver sintered conductive adhesive for microelectronic packaging and preparation method thereof
JP2983816B2 (en) Conductive resin paste
CN113257455A (en) Low-temperature-sintered lead-free conductive silver paste
CN115011294B (en) Sintered nano silver conductive adhesive for chip packaging and preparation method thereof
CN110760284A (en) Composite Ag conductive adhesive capable of effectively controlling Ag ion migration
JP2017050119A (en) Manufacturing method of electric conductive paste and electric conductive paste
CN110776848A (en) Silver powder conductive adhesive reliably connected with metal Cu interface
TWI699409B (en) Conductive composition for electromagnetic shielding, electromagnetic shielding layer formed of the same, circuit board laminate comprising the same, and method of forming electromagnetic shielding layer
JP6092754B2 (en) Conductive epoxy resin composition, solar cell using the composition, and method for producing the solar cell
CN1546591A (en) High connecting intensity thermosetting conducting resin
CN107424660A (en) A kind of back silver paste used for solar batteries and preparation method thereof
JP2005317491A (en) Conductive paste and electronic component mounting substrate using it
CN115584231B (en) Modified isotropic conductive adhesive for packaging and preparation method thereof
CN112435773B (en) Low-temperature conductive nano slurry for heterojunction solar cell and preparation method thereof
CN112768969B (en) Improved lightning protection grounding device for graphite grounding body and preparation method thereof
JP7260079B1 (en) Conductive paste, cured product, sintering accelerator, and sintering acceleration method

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
WW01 Invention patent application withdrawn after publication
WW01 Invention patent application withdrawn after publication

Application publication date: 20210430