WO1997022910A1 - Solder mask compositions - Google Patents
Solder mask compositions Download PDFInfo
- Publication number
- WO1997022910A1 WO1997022910A1 PCT/US1996/020268 US9620268W WO9722910A1 WO 1997022910 A1 WO1997022910 A1 WO 1997022910A1 US 9620268 W US9620268 W US 9620268W WO 9722910 A1 WO9722910 A1 WO 9722910A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- zwitterion
- bιs
- bisphenol
- sulfonium
- coating
- Prior art date
Links
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/004—Photosensitive materials
- G03F7/0045—Photosensitive materials with organic non-macromolecular light-sensitive compounds not otherwise provided for, e.g. dissolution inhibitors
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/004—Photosensitive materials
- G03F7/038—Macromolecular compounds which are rendered insoluble or differentially wettable
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/22—Secondary treatment of printed circuits
- H05K3/28—Applying non-metallic protective coatings
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/22—Secondary treatment of printed circuits
- H05K3/28—Applying non-metallic protective coatings
- H05K3/285—Permanent coating compositions
- H05K3/287—Photosensitive compositions
Definitions
- This invention relates to solder masks, more particularly, to liquid- photoimageable solder masks, and printed wiring boards containing such solder masks
- a feature of a preferred photoimageable solder mask coating is an ability to be developed with an aqueous, slightly alkaline solution, thereby avoiding the use of organic solvents in the developing step.
- the desired solder mask coatings should also exhibit flexibility, heat and chemical resistance, surface hardness, abrasion resistance and a rapid curing rate These stringent requirements imply that the UV curable compound and compositions must be carefully formulated in order that the solder mask can achieve commercial acceptability
- a solder is typically an alloy of about 60 percent tin and 40 percent lead and used to attach electrical components to a printed wiring board (PWB).
- a solder mask is a coating which covers or masks off selected areas of a PWB and prevents those areas from accepting any solder during vapor phase or wave solder processing In wave solder processing, the PWB is passed over a standing wave of flux and, after preheating, is passed over a standing wave of molten solder
- wave relates to a standing wave which may be either a non-aerated liquid or may be an aerated or foaming liquid which is formed by pumping up the liquid from beneath its surface
- the prime function of a solder mask is to restrict the molten solder pick-up to those areas of the PWB (holes, pads, and conductor lines) that are not covered by the solder mask
- Other functions of a solder mask are to reduce solder bridging and eliminate electrical shorts, reduce the volume of solder pick-up to obtain cost and weight savings
- Liquid-photoimageable solder masks are known, and are described, for example, in U.S. Patents 3,660,088, 3,753,720, 4,199,163, 4,361 ,640, 4,436,806, 4,508,916 and 5,006,436 However, all of the solder masks described in these patents are developed with organic solvents Although there are several commercial solder mask materials that are aqueous developable, such as Ciba-Geigy's Probimer® 65M, Probimer® 52M, and Probimer® 71 H, W R Grace's Accumask® CM 2001 , and LeaRonal's Ro ⁇ ascreen® OPSR 5600, all of them contain organic solvents in their formulations.
- liquid-photoimageable solder mask composition which is aqueous-developable, does not contain an organic solvent, can withstand the chemical attack of fluxes and the high temperature of solder baths and maintain good adhesion to the circuit board in spite of the chemicals in the fluxes and the high temperature of solder baths.
- this invention is a solder mask composition
- a solder mask composition comprising an aqueous solution of (1 ) an aryl cyclic sulfonium zwitterion or (2) an aryl cyclic sulfonium zwitterion and a polymer containing two or more carboxyl groups
- this invention is a printed wiring board containing a solder mask comprising a coating of a cured polymer prepared from (1 ) an aryl cyclic sulfonium zwitterion or (2) a mixture of an aryl cyclic sulfonium zwitterion and a polymer containing two or more carboxyl groups
- this invention is a process for producing a solder mask which comprises:
- the sulfonium zwitte ⁇ ons which can be employed in the present invention are polyfunctional monomers represented by the general formula:
- Z represents the bridging groups -O-, -S-, (CH_) c and -CR 2 ", where R" is an alkyl having from 1 to about 4 carbon atoms, and c is an integer from 1 to 10; each sulfonium group is meta or preferably ortho or para to the phenoxide group; R is hydroxyl, chlorine, bromine, an alkyl having from 1 to 16 carbon atoms (preferably from 1 to 4), or an alkoxy having from 1 to 12 carbon atoms (preferably from 1 to 4), said alkyl and alkoxy being optionally substituted with a hydroxyl group; n is an integer from 0 to 2; A' and B' independently are -CH,- or -CH(R" , wherein R'" is hydroxyl or an alkyl or hydroxyalkyl having from 1 to 8 carbon atoms; m is 0, 1 , 2 or 3; and k is 1 or 2.
- R" can also be CF 3 O- (CF 2 )
- Representative polyfunctional monomers within the scope of the above general formula include 1 ,1 '-((1 -methylethyi ⁇ dene)-b ⁇ s(6-hydroxy-3,1 -phenylene)) b ⁇ s(tetrahydroth ⁇ ophen ⁇ um hydrox ⁇ de)b ⁇ s( ⁇ nner salt), which is also referred to herein as p-bisphenol A zwitterion, 1 ,1 '-(d ⁇ methylene-b ⁇ s(oxy-4-hydroxy-2,1 - phenylene))b ⁇ s(tetrahydroth ⁇ ophen ⁇ um hydrox ⁇ de)b ⁇ s( ⁇ nner salt); 1 ,1 '-(methylene- b ⁇ s(4-hydroxy-3,1 -phenylene))b ⁇ s(tetrahydroth ⁇ ophen ⁇ um hydrox ⁇ de)b ⁇ s( ⁇ nner salt), 1 ,1 '-((1 -methylethyl ⁇ dene)-b ⁇ s(6-hydroxy-3,
- Preferred zwitte ⁇ ons which can be employed in the practice of the present invention for preparing a solder mask composition are those represented by the formulas-
- the more preferred zwitterions which can be employed in the practice of the present invention for preparing a solder mask composition are bisphenol A zwitterion and 6-fluoro bisphenol A zwitterion, with the most preferred being bisphenol A zwitterion.
- solder mask composition of the present invention can be prepared by dissolving the zwitterion in water.
- the amount of zwitterion employed depends on a variety of factors including its solubility in water, the desired viscosity of the composition, and its desired end-use, but, in general, the zwitterion can be present in an amount of from 1 to 70 weight percent, preferably from 20 to 65 weight percent, more preferably from 30 to 60 weight percent and most preferably from 40 to 55 weight percent, based on the weight of the composition.
- the solder mask composition can include a polymer containing one or more carboxyl groups for increasing the viscosity of the composition.
- the polymer containing carboxyl groups is neutralized before adding it to the sulfonium zwitterion solution to avoid gelation under acidic conditions.
- any neutralizing agent is suitable for this neutralization, ammonium hydroxide is the most preferred because it regenerates the acid during the drying of the coating prior to the curing reaction.
- the polymers containing carboxyl groups which can be employed in the practice of the present invention for preparing the solder mask composition include the polymers and copolymers of acrylic acid and methacrylic acid. Examples of these polymers are the hydrophilic. water-swellable, cross-linked acrylic acid polymers sold as CarbopolTM resins by B. F. Goodrich Company of Cleveland, Ohio.
- the amount of the polymer containing carboxyl groups most advantageously employed depends on a variety of factors, such as the specific polymer, in general, the polymer containing carboxyl groups is used in an amount of from 0.05 to 10 weight percent, preferably from 0.1 to 5 weight percent, and most preferably from about 0.5 to 1.0 weight percent, based on the weight of the composition.
- solder masks of the present invention are prepared by using as the starting substrate a partially completed printed circuit board.
- the printed circuit board is coated with an aqueous solution of an aryl cyclic sulfonium zwitterion and the coated board is exposed to a UV light source in selected areas through a photomask to polymerize the zwitterion monomer on the exposed areas.
- the coating is developed with water or alkaline aqueous solution and the unexposed, and hence unpolymerized, sulfonium zwitterion is removed, exposing the underlying metal.
- the exposed metal areas are contacted with solder which remains on the exposed metal. Wave soldering methods can be conveniently used.
- the solder in these selected areas is then used to connect various electronic components and wires.
- a 20 percent aqueous solution of bisphenol A zwitterion was poured on to the center of a 4" wafer coated with copper. Some water was allowed to evaporate. The material on the wafer was spread at 500 rpm for 10 seconds and then at 2000 rpm for 30 seconds. A non-sticky film was formed. The film was exposed to UV light through a mask for 100 seconds. After exposure, the wafer is developed in a water bath. Unexposed areas of the film are removed. The wafer is placed in an oven at 100°C for 20 minutes. A hard coating which resisted the scratch of a 6H pencil is obtained. The coating sustained solder material at 260°C. Thickness of the coating is 15 ⁇ m.
- the printed circuit drafting aids were removed The panel was placed in water and then in an oven at 90°C for 15 minutes A hard surface which sustained the scratch of a 6H pencil was obtained on areas not covered with the drafting aids For areas protected with the drafting aids, copper surface was visible. Solder was placed on copper which was not coated with the polymer. The polymer coating was not damaged by the temperature of the solder at 370°C.
- Example 3 The procedure described in Example 3 was repeated, except that a 54 percent and a 40.3 percent aqueous solution of bisphenol A zwitterion are used.
- a hard surface which sustained the scratch of a 6H pencil was obtained on areas not covered with the drafting aids
- copper surface was visible in both examples
- Solder was placed on copper which was not coated with the polymer. In both examples, the polymer coating was not damaged by the temperature of the solder at 370°C.
- Example 6 To a jar is added 91.32 g of water. A Cowles-type mixing blade-rod was attached to an air stirrer and mixing of the water was started at about 2000 rpm To the water was slowly added 0.50 g of CarbopolTM 674 (a cross-linked acrylic acid polymer from B F Goodrich) The solution was left to stir for about a half hour Two drops of 28 weight percent ammonium hydroxide solution was added to the stirring solution.
- CarbopolTM 674 a cross-linked acrylic acid polymer from B F Goodrich
- a 10 mil draw-down bar was used to cast this solution onto a glass plate. After 3 hours of drying the film under ambient conditions, the films were ready for UV curing. Half of the cast film was covered with aluminum foil to prevent exposure to UV radiation. The glass plate was placed under the UV lamp.
- the lamp used for the curing of the coatings was made by the American Ultraviolet Company. It was comprised of a Model PC10-1 -H2 200 WPI Lamp Intensity power supply and a lamp model IR 1000F. The samples were exposed to the lamp for 3 or 5 minutes A flux of 0 85 J/cm 2 was measured by a UVICURE UV Curing Radiometer (Electronics Instrument & Technology, Sterling, VA) for 3 minute exposure at the position of the coating to be cured.
- position of the coating refers to the distance of the coating from the lamp. This distance was adjusted until a flux of 0.85 J / cm 2 was registered by the UVICURE UV Curing Radiometer After 3 and 5 minute exposure times to the UV lamp, patterning was seen after rinsing with a 5 percent ammonium hydroxide solution with a pH of 12 The exposed area stayed on the glass plate and the unexposed area (that covered with the aluminum foil) rinsed off. Both the 3 and 5 minute glass plates were put in an oven at 120°C for 1 hour.
Abstract
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP96943815A EP0868685A1 (en) | 1995-12-21 | 1996-12-18 | Solder mask compositions |
JP09522988A JP2000502463A (en) | 1995-12-21 | 1996-12-18 | Solder mask composition |
KR1019980704642A KR20000064468A (en) | 1995-12-21 | 1996-12-18 | Solder Mask Composition |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US902395P | 1995-12-21 | 1995-12-21 | |
US60/009,023 | 1995-12-21 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1997022910A1 true WO1997022910A1 (en) | 1997-06-26 |
Family
ID=21735136
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1996/020268 WO1997022910A1 (en) | 1995-12-21 | 1996-12-18 | Solder mask compositions |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP0868685A1 (en) |
JP (1) | JP2000502463A (en) |
KR (1) | KR20000064468A (en) |
WO (1) | WO1997022910A1 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2006017014A2 (en) * | 2004-06-30 | 2006-02-16 | Intel Corporation | Energy harvesting molecules and photoresist technology |
EP1662317A3 (en) * | 2004-09-30 | 2006-06-28 | Fuji Photo Film Co., Ltd. | Resist composition and method of pattern formation with the same |
KR100852540B1 (en) * | 2004-06-30 | 2008-08-18 | 인텔 코포레이션 | Energy harvesting molecules and photoresist technology |
Citations (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3636052A (en) | 1969-10-15 | 1972-01-18 | Dow Chemical Co | Hydroxyarylpolymethylenesulfonium zwitterions |
US3660088A (en) | 1970-09-16 | 1972-05-02 | Grace W R & Co | Photo-resist process |
US3723386A (en) | 1971-03-29 | 1973-03-27 | Dow Chemical Co | Polymers from hydroxyarylmethylenesulfonium zwitterions |
US3753720A (en) | 1972-01-10 | 1973-08-21 | Grace W R & Co | Solder resistant photopolymer compositions |
US4001154A (en) | 1973-09-04 | 1977-01-04 | The Dow Chemical Company | Primer adhesive composition |
US4089877A (en) | 1975-10-28 | 1978-05-16 | The Dow Chemical Company | Process for producing hydroxyarylpolymethylenesulfonium salts |
US4199163A (en) | 1978-08-24 | 1980-04-22 | James Nelson | One-piece steerable sled |
US4344993A (en) * | 1980-09-02 | 1982-08-17 | The Dow Chemical Company | Perfluorocarbon-polymeric coatings having low critical surface tensions |
US4361640A (en) | 1981-10-02 | 1982-11-30 | E. I. Du Pont De Nemours And Company | Aqueous developable photopolymer compositions containing terpolymer binder |
JPS5834445A (en) | 1981-08-26 | 1983-02-28 | Japan Synthetic Rubber Co Ltd | Photosensitive material |
US4436806A (en) | 1981-01-16 | 1984-03-13 | W. R. Grace & Co. | Method and apparatus for making printed circuit boards |
US4508916A (en) | 1979-04-11 | 1985-04-02 | Minnesota Mining And Manufacturing Company | Curable substituted urethane acrylates |
EP0413087A1 (en) * | 1989-07-20 | 1991-02-20 | International Business Machines Corporation | Photosensitive composition and use thereof |
US5006436A (en) | 1988-09-20 | 1991-04-09 | Atochem North America, Inc. | UV curable compositions for making tentable solder mask coating |
-
1996
- 1996-12-18 JP JP09522988A patent/JP2000502463A/en active Pending
- 1996-12-18 KR KR1019980704642A patent/KR20000064468A/en not_active Application Discontinuation
- 1996-12-18 EP EP96943815A patent/EP0868685A1/en not_active Withdrawn
- 1996-12-18 WO PCT/US1996/020268 patent/WO1997022910A1/en not_active Application Discontinuation
Patent Citations (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3636052A (en) | 1969-10-15 | 1972-01-18 | Dow Chemical Co | Hydroxyarylpolymethylenesulfonium zwitterions |
US3660088A (en) | 1970-09-16 | 1972-05-02 | Grace W R & Co | Photo-resist process |
US3723386A (en) | 1971-03-29 | 1973-03-27 | Dow Chemical Co | Polymers from hydroxyarylmethylenesulfonium zwitterions |
US3753720A (en) | 1972-01-10 | 1973-08-21 | Grace W R & Co | Solder resistant photopolymer compositions |
US4001154A (en) | 1973-09-04 | 1977-01-04 | The Dow Chemical Company | Primer adhesive composition |
US4089877A (en) | 1975-10-28 | 1978-05-16 | The Dow Chemical Company | Process for producing hydroxyarylpolymethylenesulfonium salts |
US4199163A (en) | 1978-08-24 | 1980-04-22 | James Nelson | One-piece steerable sled |
US4508916A (en) | 1979-04-11 | 1985-04-02 | Minnesota Mining And Manufacturing Company | Curable substituted urethane acrylates |
US4344993A (en) * | 1980-09-02 | 1982-08-17 | The Dow Chemical Company | Perfluorocarbon-polymeric coatings having low critical surface tensions |
US4436806A (en) | 1981-01-16 | 1984-03-13 | W. R. Grace & Co. | Method and apparatus for making printed circuit boards |
JPS5834445A (en) | 1981-08-26 | 1983-02-28 | Japan Synthetic Rubber Co Ltd | Photosensitive material |
US4361640A (en) | 1981-10-02 | 1982-11-30 | E. I. Du Pont De Nemours And Company | Aqueous developable photopolymer compositions containing terpolymer binder |
US5006436A (en) | 1988-09-20 | 1991-04-09 | Atochem North America, Inc. | UV curable compositions for making tentable solder mask coating |
EP0413087A1 (en) * | 1989-07-20 | 1991-02-20 | International Business Machines Corporation | Photosensitive composition and use thereof |
Non-Patent Citations (5)
Title |
---|
DATABASE WPI Section Ch Week 8314, Derwent World Patents Index; Class A89, AN 83-33561K, XP002029195 * |
DATABASE WPI Section Ch Week 9027, Derwent World Patents Index; Class A35, AN 90-207340, XP002029194, ANONYMOUS: "Photocrosslinking of weakly acidic polymers - comprising coating aq. formulation on glass slide, covering with aluminium foil irradiating for 15 minutes with UV" * |
JOURNAL PAINT TECHNOLOGY, vol. 46, no. 588, January 1974 (1974-01-01), pages 41 |
RES. DISCL., 1990 |
RESEARCH DISCLOSURE, vol. 314, no. 055, 10 June 1990 (1990-06-10), EMSWORTH, GB * |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2006017014A2 (en) * | 2004-06-30 | 2006-02-16 | Intel Corporation | Energy harvesting molecules and photoresist technology |
WO2006017014A3 (en) * | 2004-06-30 | 2006-06-22 | Intel Corp | Energy harvesting molecules and photoresist technology |
US7235344B2 (en) | 2004-06-30 | 2007-06-26 | Intel Corporation | Energy harvesting molecules and photoresist technology |
KR100852540B1 (en) * | 2004-06-30 | 2008-08-18 | 인텔 코포레이션 | Energy harvesting molecules and photoresist technology |
EP1662317A3 (en) * | 2004-09-30 | 2006-06-28 | Fuji Photo Film Co., Ltd. | Resist composition and method of pattern formation with the same |
US7914965B2 (en) | 2004-09-30 | 2011-03-29 | Fujifilm Corporation | Resist composition and method of pattern formation with the same |
Also Published As
Publication number | Publication date |
---|---|
EP0868685A1 (en) | 1998-10-07 |
JP2000502463A (en) | 2000-02-29 |
KR20000064468A (en) | 2000-11-06 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP0065352B1 (en) | Light-sensitive polymer composition | |
EP0119719B1 (en) | Radiation sensitive polymer composition | |
JP3511146B2 (en) | Photopolymerizable composition | |
JPH05339356A (en) | Photopolymerizable unsaturated compound, and photosensitive resin composition of alkali development type | |
JP3170174B2 (en) | Polyimide resin composition | |
EP1205804B1 (en) | Photosensitive resin composition and circuit board | |
KR19990077642A (en) | Developer For Photosensitive Polyimide Precursor, and Method of Using It For Patterning | |
EP0819267B1 (en) | Coating compositions | |
JPH1152572A (en) | Photosensitive resin composition and pattern forming method by using the same | |
WO1997022910A1 (en) | Solder mask compositions | |
EP0715490A2 (en) | Method of preparing multilayer wiring board | |
JP2005089659A (en) | Resin composition | |
GB2032939A (en) | Coating Compositions | |
JPH11102069A (en) | Positive photosensitive resin composition | |
JP2003295433A (en) | Photosensitive resin composition | |
JP3651529B2 (en) | Photosensitive resin composition | |
JPH0496067A (en) | Positive photoresist composition | |
EP0424866B1 (en) | Liquid solder mask composition | |
JP3241452B2 (en) | Unsaturated group-containing carboxylic acid resin composition and solder resist resin composition | |
SE445647B (en) | SET TO EDUCATE A SAMPLE OF SOLID METAL ON A LAYER OF AN ELECTRICALLY CONDUCTIVE METAL | |
JPH11217502A (en) | Photosensitive polyimide precursor solution, polyimide coated film obtained therefrom and production of the same | |
TWI704174B (en) | Curable resin composition, dry film, cured product, and printed wiring board | |
JPS63167349A (en) | Photosensitive resin composition | |
JP4090311B2 (en) | Developer for photosensitive polyimide precursor and pattern manufacturing method using the same | |
JP2003295435A (en) | Photosensitive resin composition |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): JP KR SG US |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE |
|
DFPE | Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101) | ||
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
WWE | Wipo information: entry into national phase |
Ref document number: 1996943815 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1019980704642 Country of ref document: KR |
|
WWP | Wipo information: published in national office |
Ref document number: 1996943815 Country of ref document: EP |
|
WWW | Wipo information: withdrawn in national office |
Ref document number: 1996943815 Country of ref document: EP |
|
WWP | Wipo information: published in national office |
Ref document number: 1019980704642 Country of ref document: KR |
|
WWW | Wipo information: withdrawn in national office |
Ref document number: 1019980704642 Country of ref document: KR |