US20040112869A1 - Cleaning composition - Google Patents
Cleaning composition Download PDFInfo
- Publication number
- US20040112869A1 US20040112869A1 US10/658,702 US65870203A US2004112869A1 US 20040112869 A1 US20040112869 A1 US 20040112869A1 US 65870203 A US65870203 A US 65870203A US 2004112869 A1 US2004112869 A1 US 2004112869A1
- Authority
- US
- United States
- Prior art keywords
- acid
- composition
- persulfate
- copper
- boric acid
- 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.)
- Abandoned
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- C23F1/00—Etching metallic material by chemical means
- C23F1/10—Etching compositions
- C23F1/14—Aqueous compositions
- C23F1/16—Acidic compositions
- C23F1/18—Acidic compositions for etching copper or alloys thereof
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
- C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
- C23G1/02—Cleaning or pickling metallic material with solutions or molten salts with acid solutions
- C23G1/10—Other heavy metals
- C23G1/103—Other heavy metals copper or alloys of copper
-
- 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
- H05K3/38—Improvement of the adhesion between the insulating substrate and the metal
- H05K3/382—Improvement of the adhesion between the insulating substrate and the metal by special treatment of the metal
- H05K3/383—Improvement of the adhesion between the insulating substrate and the metal by special treatment of the metal by microetching
-
- 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
- H05K2203/00—Indexing scheme relating to apparatus or processes for manufacturing printed circuits covered by H05K3/00
- H05K2203/07—Treatments involving liquids, e.g. plating, rinsing
- H05K2203/0779—Treatments involving liquids, e.g. plating, rinsing characterised by the specific liquids involved
- H05K2203/0786—Using an aqueous solution, e.g. for cleaning or during drilling of holes
- H05K2203/0796—Oxidant in aqueous solution, e.g. permanganate
Definitions
- the present invention is directed to an improved cleaning composition for metal. More specifically, the present invention is directed to an improved cleaning composition for metal which improves metal saturation and crystallization during microetching.
- Metal etchants in particular the chromium salts, create a deleterious environmental impact. Chromium salts also are known to be carcinogenic to humans and their use and disposal are problematic.
- Nitric acid either alone or in combination with sulfuric or copper nitrate, has been reported by Battey (U.S. Pat. No. 4,695,348) to be useful for etching copper in circuit boards.
- nitrogenous oxide gas is a byproduct of this process.
- the process provides anisotropic etching only for certain orientations of copper (i.e., the top surface of the copper crystal structure must have a Miller index of (111) and (200) orientation). This requires first sputtering copper and then electrodepositing more copper. In lieu of sputtered copper, evaporative deposition or electroless deposition also is possible.
- Alkaline-ammonia compositions are used commercially because they are relatively fast, have substantial copper-carrying capacity and are reasonably tolerant of some metal resists and some dry film resists.
- these same compositions have poor selectivity for copper versus other metals and alloys.
- Significant process control is required to achieve acceptable selectivity.
- Such compositions may not work well with fine line copper geometries.
- the dissolved copper is difficult to recover.
- fumes from ammonia present the worker exposure concerns.
- Hydrogen peroxide-sulfuric acid compositions used in copper etching processes are very clean to operate and may be recycled. However, such compositions have relatively slow etching rates and require substantial cooling for stability control due to the autodecomposition reaction of the hydrogen peroxide. Additionally, both the performance of the process and the decomposition of the hydrogen peroxide are sensitive to trace impurities via homo- or hetero-catalysis. Stabilizers are necessary for peak performance but these are metal specific. Brasch (U.S. Pat. No. 4,378,270) teaches phenol-sulfonic acid for copper containing solutions. It also is known from Alderuccio et al. (U.S. Pat. No.
- the process generates voluminous quantities of copper sulfate, which are difficult to reclaim or dispose of.
- Copper may be electroplated out from the copper sulfate. Typically, however, this copper does not deposit as an adherent homogeneous ingot deposit, but rather comes out as a powder which sluffs off and makes recovery difficult.
- Brasch describes the use of phosphoric acid to assist in producing smooth adherent copper deposits on a cathodic surface, but this is at the expense of a slower etch rate.
- Etch compositions containing persulfate without hydrogen peroxide eliminate the problems associated with hydrogen peroxide etch solutions.
- Etch solutions of potassium monopersulfate are prepared by dissolving a desired amount of the salt in a 1% to 3% by volume sulfuric acid solution. The solution is then put into production for lightly etching copper as part of the surface process prior to a chemical process, such as plating, oxide coating, or solder coating. As the panels containing copper circuits are cleaned in the etch bath, the copper is lightly etched, and the surface layers of copper are removed and dissolve in the bath as copper sulfate salts. The process of cleaning is called a microetch due to the removal of surface layers of copper.
- Amounts of copper etched away in the surface preparation step are from 10 to 60 microinches, depending on the particular chemical process to follow. As work is processed through the bath, the copper concentration continues to increase and the concentration of the persulfate solution decreases. Process control is done by a measurement of the copper etch rate by a weight-loss method. The persulfate solution concentration is determined by a redox titration called the available oxygen concentration (AOC) because the active compound, potassium monopersulfate, is an oxidizing agent that contains oxygen. Replenishment of the potassium monopersulfate solution may be made according to the results of the analysis for AOC taking into consideration the etch rate and copper concentration.
- AOC available oxygen concentration
- a persulfate microetch solution which provides for more metal solubility, such as improved copper solubility, in the microetch process may increase the metal parts microetched or cleaned during fabrication of microelectronic packages.
- a particularly suitable persulfate etch solution for copper is one which has a fluorine containing acid.
- a number of persulfate solutions which have a fluorine containing acid suffer from formation and precipitation of an insoluble compound.
- the insoluble compound may be composed of the elements potassium, fluorine and silicon such as a mixture of potassium fluoroborate and potassium fluorosilicate.
- the exact composition of the precipitate is yet uncertain. Nevertheless, the insoluble compound may result in contamination of substrates which are being microetched as well as leading to contamination of microelectronic products. Accordingly, there is a need for an improved persulfate microetch composition.
- the present invention is directed to a composition that includes a persulfate, fluorine containing acids, boric acid or salts of boric acid.
- the composition may also include one or more additional inorganic acids or salts thereof, and adjuvants to assist in cleaning a metal.
- the present invention also is directed to a method of making the composition.
- the composition may be employed as a microetch solution for cleaning metal such as in the manufacture of printed circuit or wiring boards.
- the present invention also is directed to a method of cleaning or microetching a metal.
- the persulfate composition of the present invention is highly suitable for microethcing metal in the manufacture of printed circuit boards and wiring. Accordingly, the present invention also is directed to a method of making printed circuit and wiring boards.
- the persulfate composition of the present invention increases the copper saturation and crystallization concentration in microetch solutions which results in higher yields of metal parts per liter of microetch solution. Accordingly, the persulfate compositions improve microetch efficiency.
- the persulfate compositions also have an increased useful life, and reduce the volume of spent microetch solutions or baths which are sent to waste treatment for chemical precipitation and disposal. Thus, the persulfate compositions are environmentally friendly. Further, the persulfate compositions make metal recycling/recovery processes of electrowinning more efficient due to the increased metal concentrations in microetching baths.
- Another advantage of the persulfate compositions of the present invention is that insoluble precipitates do not form in the microetch solutions or baths.
- Such insoluble precipitates may contaminate microcomponents during the manufacture of printed circuit and wiring boards. Additionally, the insoluble precipitates must be sent to waste treatment to prevent contamination of the environment. Such insoluble precipitates undesirably add to the cost of manufacturing microelectronic packages.
- the present invention is directed to a composition that includes a persulfate, fluorine containing acids, boric acid or salts of boric acid.
- the composition may also include one or more additional inorganic acids or salts of inorganic acids, and adjuvants to assist in cleaning a metal.
- the composition may be employed as a cleaning composition for cleaning metal such as in the fabrication of microelectronic packages and the manufacture of printed circuit and wiring boards. While the composition of the present invention may be employed to clean various metals and metal alloys, the persulfate composition is highly suitable for cleaning copper and copper alloys. Cleaning within the scope of the present invention refers to microetching.
- the process of cleaning is called a microetch or microetching because application of the persulfate composition removes surface layers of a metal, such as copper, or a metal alloy.
- the amount of metal removed may vary depending on the metal being microetched and the particular chemical process which follows the microetch.
- the amount of copper microetched away with a persulfate compositon ranges from 5 to 80 microinches (2.54 centimeters/inch), more typically from 10 to 60 microinches.
- the persulfate compositions may be applied to a metal for microetching by any suitable method as discussed below.
- the persulfate compositions are aqueous solutions.
- the persulfate compositions have from 1.0% by weight to 35% by weight of a persulfate oxidizing agent, preferably from 10% by weight to 25% by weight of the composition.
- a persulfate oxidizing agent preferably from 10% by weight to 25% by weight of the composition.
- Any suitable source of persulfate may be employed to practice the present invention.
- sources of persulfate include, but are not limited to, alkali metal monopersulfate salts such as sodium and potassium monopersulfate.
- a preferred monopersulfate is potassium monopersulfate.
- Persulfate compositions also contain boric acid or a salt of boric acid or a mixture of boric acid and a salt of boric acid.
- Boric acid or a salt of boric acid ranges from 0.1% to 10% by weight of the persulfate composition, preferably from 1% to 5% by weight of the composition.
- Any suitable form of boric acid or salt of boric acid may be used to practice the present invention. Examples of suitable forms of boric acid include, but are not limited to, technical grade boric acid.
- Suitable salts of boric acid include, but are not limited to, alkali metal salts such as lithium, sodium and potassium salts.
- Fluorine containing acids are employed in the persulfate compositions in amounts of from 0.1% by weight to 10% by weight, preferably from 1.0% to 5% by weight of the composition.
- Any suitable fluorine containing acid may be employed in the present invention.
- fluorine containing acids include, but are not limited to, hydrofluoric acid, fluoroboric acid, fluorosilic acid or mixtures thereof.
- a preferred fluorine containing acid is fluoroboric acid.
- Additional inorganic acids that may be employed in the compositions of the present invention include, but are not limited to, sulfuric acid, phosphoric acid, and phosphorous acid or mixtures thereof. Hydrochloric acid and nitric acid preferably are not employed to practice the present invention due to toxic byproducts such as nitrogen oxides and chlorine gas.
- the additional inorganic acids may be employed in ranges of from 0.5% by weight to 15% by weight of the composition, preferably from 5% to 10% by weight of the composition.
- the persulfate composition also may contain optional adjuvants.
- Adjuvants such as surfactants and banking agents may have beneficial effects for the microetchant formulation.
- Surfactants are incorporated into the composition primarily to reduce adhesion of air or gas bubbles to the microetched surface of a metal. If this is not provided for, there is the possibility of creating irregularly-microetched surfaces due to the bubbles preventing fresh microetchant from contacting the metal surface.
- surfactants may be anionic, cationic, nonionic or inner salt types.
- Anionic surfactants may contain phosphate, sulfate, sulfonate or sulfate groups attached to long chain alkyl or aryl moieties.
- Cationic surfactants may be quaternary ammonium salts with a long chain alkyl or aryl moiety.
- Nonionic surfactants may be composed of long chain alkyl or aryl moieties possessing polyethylene oxy functionality.
- Inner salt surfactants contain both anionic and cationic functionalities that are equally balanced to create a charge-neutral material.
- the present invention may employ all types of surfactants described above.
- banking agents are employed to provide greater anisotropy during the microetching process. The greater the difference between vertical and lateral etching rates, the higher is the anisotropy of the process.
- suitable banking agents include, but are not limited to, benzotriazoles such as the unsubstituted benzotriazoles.
- the amounts of optional adjuvants added to the persulfate microetch composition of the present invention may vary depending on the particular microetch process employed and the type of metal to be microetched. Typically adjuvants are employed in conventional amounts well known in the art.
- the remainder of the persulfate compositions of the present invention is water to bring the compositions to 100% by weight.
- the persulfate compositions may be utilized over a wide pH range. Typically the persulfate composition may be utilized over a pH range of from less than 0 to 7.0, preferably from a pH of 2.0 to a pH of 5.0.
- the components of the persulfate composition may be combined together by any suitable method to form an aqueous microetch composition or bath solution.
- the additional inorganic acids are added to a persulfate composition after boric acid or a salt of boric acid has been added or solubilized in the persulfate composition.
- the procedure of adding or solubilizing boric acid or a salt of boric acid is most preferable when the acid employed is sulfuric acid.
- Some grades of boric acid or salts of boric acid present a solubility problem in the presence of some inorganic acids. Accordingly, adding an inorganic acid such as sulfuric acid, phosphoric acid, phosphorous acid, or mixtures thereof to a microetch solution separately from the other components of the solution is preferred.
- the addition of boric acid or a salt of boric acid to the persulfate composition unexpectedly prevents the formation of an undesirable insoluble precipitate in microetch solutions.
- the insoluble precipitate may cause contamination of metal which is being microetched and also may contaminate the microelectronic packages and printed circuit boards.
- the nature of the insoluble precipitate may be a salt of potassium, fluorine or silicon.
- the compositions of the present invention also increase copper saturation and crystallization concentration to greater than 40 grams/Liter in contrast to conventional persulfate microetches which have a lower copper saturation and crystallization concentration of 10 to 15 grams/Liter. Accordingly, the persulfate compositions show an increase in copper saturation and crystallization of 2 to 3 times.
- compositions of the present invention include reduced volume of spent baths to be sent to waste treatment for chemical precipitation and disposal by a factor of 2 to 3; increases the useful life of a persulfate bath by a factor of 2 to 3; and makes the copper recycling/recovery process of electrowinning more efficient due to the significantly higher copper concentration in solution.
- Another advantage of the present invention is the reduced process operating cost by a factor of 2 to 3. Further, since less waste is produced by the microetching methods of the present invention, the present invention is environmentally friendly.
- the microetchant process of the present invention may be performed at room temperature.
- the microetchant process of the present invention is performed at temperatures of from 80 to 100° F. (27 to 38° C.).
- the persulfate composition may be applied to a metal by spraying, or immersion or any other suitable method known in the art.
- the persulfate composition may be employed to etch many metals such as copper, copper in the presence of nickel, or nickel alloys, or overcoated with noble metals such as porous gold and palladium.
- the persulfate composition also may be employed to microetch solder (Sn/Pb).
- the persulfate composition of the present invention may be employed in any method where microetching is employed.
- the persulfate composition of the present invention may be employed in the manufacture of printed circuit or wiring boards as discussed below.
- a copper-clad laminate is formed by taking a 1 ⁇ 2 oz copper foil and a dielectric substrate or support and placing them in direct contact and applying pressure.
- dielectric support examples include thermoplastic and thermosetting resins, ceramics, glass and composites of glass cloth reinforced or unreinforced thermoset resins, specifically phenolic resins such as ABS, polyimides, and polymeric vinyl chloride.
- a photoresist material is applied by either hot roll lamination, vacuum lamination or spin coating techniques.
- the photoresist material may be either negative-working (i.e. the imaged areas are hardened and unimaged areas are developed to uncover the underlying copper foil) or positive-working (i.e. the imaged areas are softened and eventually developed to uncover the underlying copper foil).
- the photoresist material may be applied in liquid form from either an aqueous or solvent based formulation.
- Materials for positive-working photoresist may be based on phenol-aldehyde condensations as the binder resin and o-quinonediazide as the photoactive compound.
- Imaging the photoresist is performed by using glass masters or film and exposing using electromagnetic radiation, preferably ultraviolet radiation in the spectral region of from 365 to 435 nanometers.
- Development of the unexposed areas may be accomplished with organic solvents or aqueous solutions which dissolve the unhardened photoresist.
- solvents include propylene carbonate, gamma butyrolactone, and various ester formulations.
- Aqueous solutions include sodium carbonate.
- Propylene carbonate developer is typically accomplished at from 20° to 30° C., for 3 to 5 minutes in a spray developer at 30 to 40 psi spray pressure.
- Sodium carbonate development is typically accomplished at 80° F. (27° C.), for 3 to 5 minutes in a spray developer at 15 to 25 psi spray pressure.
- Nickel or a nickel alloy may be electroplated or electrolessly plated onto the uncovered copper surfaces that are formed during the development of the imaged photoresist.
- Solvent strip solvents may include propylene carbonate and benzyl alcohol.
- a preferred aqueous solvent is sodium hydroxide.
- Solvent stripping in propylene carbonate may be accomplished at 90° C. to 105° C. for 5 to 8 minutes in a spray stripper at 50 to 60 psi spray pressure.
- Aqueous stripping may be accomplished at 135° F. to 145° F. (57° C. to 63° C.) for 5 to 8 minutes in a spray stripper at 20 to 30 psi spray pressure.
- the unplated copper is microetched leaving any nickel-plated copper circuit patterns.
- the unplated copper is microetched with an aqueous microetch solution of potassium monopersulfate in sulfuric acid with fluoroboric acid and boric acid.
- Microetching may be performed in a spray etcher at 85° F. to 95° F. (29° C. to 35° C.) with a 20-30 psi spray pressure.
- the microetching may also be performed by immersion.
- the microetch rate is greater than 0.001 inches per minute (2.54 centimeters/inch).
- a cleaning bath for copper is prepared by dissolving potassium monopersulfate in a solution of sulfuric, boric and fluoroboric acids.
- a concentrate composed of 30.0-50.0 grams/Liter of boric acid and 35.0-55.0 grams/Liter of fluoroboric acid is prepared without sulfuric acid.
- the sulfuric acid may be added separately to the microetch solution apart from the concentrate.
- the concentrate containing the boric acid and fluoroboric acid may be employed in the microetch solution at 6.5% to 8.5% by volume.
- a copper cleaning bath is prepared in a 100 U.S. gallon tank by dissolving 2.5 U.S. gallons of sulfuric acid 96% by weight in 100 U.S. gallons of water. 100 pounds (453.6 grams/pound) of potassium monopersulfate are added and dissolved with mixing.
- the bath is used in a cleaning process to prepare copper circuits on a panel for the application of solder in a hot air solder leveling process. Panels are processed through the bath and through the HASL machine. As the copper concentration increases in the bath from copper removal from circuits to the range of 12-15 grams/Liter, blue crystals of copper salts may be seen on the parts of the HASL machine where solution evaporates leaving behind dry salts.
- a cleaning bath is prepared in a 100 U.S. gallon tank by the addition of 95 U.S. gallons of water and 5 U.S. gallons of the liquid additive concentrate described in Example 1 above followed by dissolving 100 pounds of potassium monopersulfate.
- the bath is used in a process for cleaning copper circuits prior to the application of solder in the HASL process of Example 2. Panels are processed through the copper cleaner and the HASL process and observations are made for the formation of copper salts above the level of the bath.
- the copper concentration is more than 40 grams/Liter before the dark blue solution began to form blue salts around the level of the bath.
- Example 1 This corresponds to 24,000 square-feet of copper-containing panels or more than 3 times the yield of Example 2 before the bath is dumped, treated for disposal and the copper recovered.
- the operating cost of Example 3 is about 1 ⁇ 3 that of the process in Example 2.
- the persulfate composition of the present invention as disclosed in Example 1 is an improved persulfate microetch solution.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Metallurgy (AREA)
- General Chemical & Material Sciences (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Organic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Microelectronics & Electronic Packaging (AREA)
- ing And Chemical Polishing (AREA)
- Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
- Cleaning By Liquid Or Steam (AREA)
- Detergent Compositions (AREA)
Abstract
A composition composed of a persulfate, boric acid, a fluorine containing acid and an inorganic acid. Adjuvants also may be included in the composition. The composition may be employed as a microetch solution in the fabrication of microelectronic packages.
Description
- The present invention is directed to an improved cleaning composition for metal. More specifically, the present invention is directed to an improved cleaning composition for metal which improves metal saturation and crystallization during microetching.
- Many chemical etching processes for metals, such as copper, on microelectronic substrates are performed with either copper or ferric chlorides, chromium salts, alkaline-ammonia, hydrogen peroxide-sulfuric acid or nitric acid compositions. Such compositions have certain limitations and disadvantages as described below.
- Metal etchants, in particular the chromium salts, create a deleterious environmental impact. Chromium salts also are known to be carcinogenic to humans and their use and disposal are problematic.
- Nitric acid, either alone or in combination with sulfuric or copper nitrate, has been reported by Battey (U.S. Pat. No. 4,695,348) to be useful for etching copper in circuit boards. However, nitrogenous oxide gas is a byproduct of this process. Also, the process provides anisotropic etching only for certain orientations of copper (i.e., the top surface of the copper crystal structure must have a Miller index of (111) and (200) orientation). This requires first sputtering copper and then electrodepositing more copper. In lieu of sputtered copper, evaporative deposition or electroless deposition also is possible.
- Alkaline-ammonia compositions are used commercially because they are relatively fast, have substantial copper-carrying capacity and are reasonably tolerant of some metal resists and some dry film resists. However, these same compositions have poor selectivity for copper versus other metals and alloys. Significant process control is required to achieve acceptable selectivity. Such compositions may not work well with fine line copper geometries. Furthermore, the dissolved copper is difficult to recover. Additionally, fumes from ammonia present the worker exposure concerns.
- Hydrogen peroxide-sulfuric acid compositions used in copper etching processes are very clean to operate and may be recycled. However, such compositions have relatively slow etching rates and require substantial cooling for stability control due to the autodecomposition reaction of the hydrogen peroxide. Additionally, both the performance of the process and the decomposition of the hydrogen peroxide are sensitive to trace impurities via homo- or hetero-catalysis. Stabilizers are necessary for peak performance but these are metal specific. Brasch (U.S. Pat. No. 4,378,270) teaches phenol-sulfonic acid for copper containing solutions. It also is known from Alderuccio et al. (U.S. Pat. No. 3,269,881) that these compositions are adversely affected by chloride or bromide ion at levels of 2 mg/Liter, causing reduced etch rates. Elias (U.S. Pat. No. 4,130,455) teaches that the addition of sodium or potassium thiosulfate can counteract this effect.
- Use of the above additives does not address the basic problem of the catalytic decomposition of the peroxide discussed hereinbefore. This decomposition has two important implications: firstly, the depletion of the peroxide in the etchant solution reduces the etchant rate; and secondly, there is potential for uncontrolled decomposition of large volumes of high temperature solutions, generating high concentrations of oxygen and increasing the safety risks therefrom. Because decomposition of the peroxide is accelerated at elevated temperatures, processing temperatures must be kept low. This adversely affects the rate of the etching process and exacerbates the already low copper-carrying capacity of the peroxide-sulfuric acid composition. Finally, the process generates voluminous quantities of copper sulfate, which are difficult to reclaim or dispose of. Copper may be electroplated out from the copper sulfate. Typically, however, this copper does not deposit as an adherent homogeneous ingot deposit, but rather comes out as a powder which sluffs off and makes recovery difficult. Brasch describes the use of phosphoric acid to assist in producing smooth adherent copper deposits on a cathodic surface, but this is at the expense of a slower etch rate.
- Etch compositions containing persulfate without hydrogen peroxide eliminate the problems associated with hydrogen peroxide etch solutions. Etch solutions of potassium monopersulfate are prepared by dissolving a desired amount of the salt in a 1% to 3% by volume sulfuric acid solution. The solution is then put into production for lightly etching copper as part of the surface process prior to a chemical process, such as plating, oxide coating, or solder coating. As the panels containing copper circuits are cleaned in the etch bath, the copper is lightly etched, and the surface layers of copper are removed and dissolve in the bath as copper sulfate salts. The process of cleaning is called a microetch due to the removal of surface layers of copper. Amounts of copper etched away in the surface preparation step are from 10 to 60 microinches, depending on the particular chemical process to follow. As work is processed through the bath, the copper concentration continues to increase and the concentration of the persulfate solution decreases. Process control is done by a measurement of the copper etch rate by a weight-loss method. The persulfate solution concentration is determined by a redox titration called the available oxygen concentration (AOC) because the active compound, potassium monopersulfate, is an oxidizing agent that contains oxygen. Replenishment of the potassium monopersulfate solution may be made according to the results of the analysis for AOC taking into consideration the etch rate and copper concentration. When the copper concentration exceeds 12 to 15 grams/Liter in the bath, it is transferred to a waste treatment tank to remove the copper and a new bath is prepared. While the persulfate etch overcomes some of the problems associated with the hydrogen peroxide-sulfuric acid compositons described above, there is still a need for improvement in the microetch processes which employ persulfate.
- A persulfate microetch solution which provides for more metal solubility, such as improved copper solubility, in the microetch process may increase the metal parts microetched or cleaned during fabrication of microelectronic packages. A particularly suitable persulfate etch solution for copper is one which has a fluorine containing acid. However, a number of persulfate solutions which have a fluorine containing acid suffer from formation and precipitation of an insoluble compound. The insoluble compound may be composed of the elements potassium, fluorine and silicon such as a mixture of potassium fluoroborate and potassium fluorosilicate. However, the exact composition of the precipitate is yet uncertain. Nevertheless, the insoluble compound may result in contamination of substrates which are being microetched as well as leading to contamination of microelectronic products. Accordingly, there is a need for an improved persulfate microetch composition.
- The present invention is directed to a composition that includes a persulfate, fluorine containing acids, boric acid or salts of boric acid. The composition may also include one or more additional inorganic acids or salts thereof, and adjuvants to assist in cleaning a metal. The present invention also is directed to a method of making the composition. The composition may be employed as a microetch solution for cleaning metal such as in the manufacture of printed circuit or wiring boards. Thus, the present invention also is directed to a method of cleaning or microetching a metal. The persulfate composition of the present invention is highly suitable for microethcing metal in the manufacture of printed circuit boards and wiring. Accordingly, the present invention also is directed to a method of making printed circuit and wiring boards.
- Advantageously, the persulfate composition of the present invention increases the copper saturation and crystallization concentration in microetch solutions which results in higher yields of metal parts per liter of microetch solution. Accordingly, the persulfate compositions improve microetch efficiency. The persulfate compositions also have an increased useful life, and reduce the volume of spent microetch solutions or baths which are sent to waste treatment for chemical precipitation and disposal. Thus, the persulfate compositions are environmentally friendly. Further, the persulfate compositions make metal recycling/recovery processes of electrowinning more efficient due to the increased metal concentrations in microetching baths. Another advantage of the persulfate compositions of the present invention is that insoluble precipitates do not form in the microetch solutions or baths. Such insoluble precipitates may contaminate microcomponents during the manufacture of printed circuit and wiring boards. Additionally, the insoluble precipitates must be sent to waste treatment to prevent contamination of the environment. Such insoluble precipitates undesirably add to the cost of manufacturing microelectronic packages.
- The present invention is directed to a composition that includes a persulfate, fluorine containing acids, boric acid or salts of boric acid. The composition may also include one or more additional inorganic acids or salts of inorganic acids, and adjuvants to assist in cleaning a metal. The composition may be employed as a cleaning composition for cleaning metal such as in the fabrication of microelectronic packages and the manufacture of printed circuit and wiring boards. While the composition of the present invention may be employed to clean various metals and metal alloys, the persulfate composition is highly suitable for cleaning copper and copper alloys. Cleaning within the scope of the present invention refers to microetching. The process of cleaning is called a microetch or microetching because application of the persulfate composition removes surface layers of a metal, such as copper, or a metal alloy. The amount of metal removed may vary depending on the metal being microetched and the particular chemical process which follows the microetch. Typically, the amount of copper microetched away with a persulfate compositon ranges from 5 to 80 microinches (2.54 centimeters/inch), more typically from 10 to 60 microinches. The persulfate compositions may be applied to a metal for microetching by any suitable method as discussed below. Typically the persulfate compositions are aqueous solutions.
- The persulfate compositions have from 1.0% by weight to 35% by weight of a persulfate oxidizing agent, preferably from 10% by weight to 25% by weight of the composition. Any suitable source of persulfate may be employed to practice the present invention. Examples of sources of persulfate include, but are not limited to, alkali metal monopersulfate salts such as sodium and potassium monopersulfate. A preferred monopersulfate is potassium monopersulfate.
- Persulfate compositions also contain boric acid or a salt of boric acid or a mixture of boric acid and a salt of boric acid. Boric acid or a salt of boric acid ranges from 0.1% to 10% by weight of the persulfate composition, preferably from 1% to 5% by weight of the composition. Any suitable form of boric acid or salt of boric acid may be used to practice the present invention. Examples of suitable forms of boric acid include, but are not limited to, technical grade boric acid. Suitable salts of boric acid include, but are not limited to, alkali metal salts such as lithium, sodium and potassium salts.
- Fluorine containing acids are employed in the persulfate compositions in amounts of from 0.1% by weight to 10% by weight, preferably from 1.0% to 5% by weight of the composition. Any suitable fluorine containing acid may be employed in the present invention. Examples of such fluorine containing acids include, but are not limited to, hydrofluoric acid, fluoroboric acid, fluorosilic acid or mixtures thereof. A preferred fluorine containing acid is fluoroboric acid.
- Additional inorganic acids that may be employed in the compositions of the present invention include, but are not limited to, sulfuric acid, phosphoric acid, and phosphorous acid or mixtures thereof. Hydrochloric acid and nitric acid preferably are not employed to practice the present invention due to toxic byproducts such as nitrogen oxides and chlorine gas. The additional inorganic acids may be employed in ranges of from 0.5% by weight to 15% by weight of the composition, preferably from 5% to 10% by weight of the composition.
- The persulfate composition also may contain optional adjuvants. Adjuvants such as surfactants and banking agents may have beneficial effects for the microetchant formulation. Surfactants are incorporated into the composition primarily to reduce adhesion of air or gas bubbles to the microetched surface of a metal. If this is not provided for, there is the possibility of creating irregularly-microetched surfaces due to the bubbles preventing fresh microetchant from contacting the metal surface. Typically surfactants may be anionic, cationic, nonionic or inner salt types. Anionic surfactants may contain phosphate, sulfate, sulfonate or sulfate groups attached to long chain alkyl or aryl moieties.
- Cationic surfactants may be quaternary ammonium salts with a long chain alkyl or aryl moiety. Nonionic surfactants may be composed of long chain alkyl or aryl moieties possessing polyethylene oxy functionality. Inner salt surfactants contain both anionic and cationic functionalities that are equally balanced to create a charge-neutral material. The present invention may employ all types of surfactants described above.
- Banking agents are employed to provide greater anisotropy during the microetching process. The greater the difference between vertical and lateral etching rates, the higher is the anisotropy of the process. Examples of suitable banking agents include, but are not limited to, benzotriazoles such as the unsubstituted benzotriazoles.
- The amounts of optional adjuvants added to the persulfate microetch composition of the present invention may vary depending on the particular microetch process employed and the type of metal to be microetched. Typically adjuvants are employed in conventional amounts well known in the art. The remainder of the persulfate compositions of the present invention is water to bring the compositions to 100% by weight.
- The persulfate compositions may be utilized over a wide pH range. Typically the persulfate composition may be utilized over a pH range of from less than 0 to 7.0, preferably from a pH of 2.0 to a pH of 5.0.
- The components of the persulfate composition may be combined together by any suitable method to form an aqueous microetch composition or bath solution. Preferably, the additional inorganic acids are added to a persulfate composition after boric acid or a salt of boric acid has been added or solubilized in the persulfate composition. The procedure of adding or solubilizing boric acid or a salt of boric acid is most preferable when the acid employed is sulfuric acid. Some grades of boric acid or salts of boric acid present a solubility problem in the presence of some inorganic acids. Accordingly, adding an inorganic acid such as sulfuric acid, phosphoric acid, phosphorous acid, or mixtures thereof to a microetch solution separately from the other components of the solution is preferred.
- While not being bound to theory, the addition of boric acid or a salt of boric acid to the persulfate composition unexpectedly prevents the formation of an undesirable insoluble precipitate in microetch solutions. The insoluble precipitate may cause contamination of metal which is being microetched and also may contaminate the microelectronic packages and printed circuit boards. The nature of the insoluble precipitate may be a salt of potassium, fluorine or silicon. The compositions of the present invention also increase copper saturation and crystallization concentration to greater than 40 grams/Liter in contrast to conventional persulfate microetches which have a lower copper saturation and crystallization concentration of 10 to 15 grams/Liter. Accordingly, the persulfate compositions show an increase in copper saturation and crystallization of 2 to 3 times.
- Other advantages of the compositions of the present invention include reduced volume of spent baths to be sent to waste treatment for chemical precipitation and disposal by a factor of 2 to 3; increases the useful life of a persulfate bath by a factor of 2 to 3; and makes the copper recycling/recovery process of electrowinning more efficient due to the significantly higher copper concentration in solution. Another advantage of the present invention is the reduced process operating cost by a factor of 2 to 3. Further, since less waste is produced by the microetching methods of the present invention, the present invention is environmentally friendly.
- The microetchant process of the present invention may be performed at room temperature. Preferably, the microetchant process of the present invention is performed at temperatures of from 80 to 100° F. (27 to 38° C.). The persulfate composition may be applied to a metal by spraying, or immersion or any other suitable method known in the art.
- The persulfate composition may be employed to etch many metals such as copper, copper in the presence of nickel, or nickel alloys, or overcoated with noble metals such as porous gold and palladium. The persulfate composition also may be employed to microetch solder (Sn/Pb).
- The persulfate composition of the present invention may be employed in any method where microetching is employed. For example, the persulfate composition of the present invention may be employed in the manufacture of printed circuit or wiring boards as discussed below.
- A copper-clad laminate is formed by taking a ½ oz copper foil and a dielectric substrate or support and placing them in direct contact and applying pressure. Examples of materials that may be used for the dielectric support include thermoplastic and thermosetting resins, ceramics, glass and composites of glass cloth reinforced or unreinforced thermoset resins, specifically phenolic resins such as ABS, polyimides, and polymeric vinyl chloride.
- A photoresist material is applied by either hot roll lamination, vacuum lamination or spin coating techniques. The photoresist material may be either negative-working (i.e. the imaged areas are hardened and unimaged areas are developed to uncover the underlying copper foil) or positive-working (i.e. the imaged areas are softened and eventually developed to uncover the underlying copper foil). The photoresist material may be applied in liquid form from either an aqueous or solvent based formulation. Materials for positive-working photoresist may be based on phenol-aldehyde condensations as the binder resin and o-quinonediazide as the photoactive compound.
- Imaging the photoresist is performed by using glass masters or film and exposing using electromagnetic radiation, preferably ultraviolet radiation in the spectral region of from 365 to 435 nanometers. Development of the unexposed areas (negative resist system) may be accomplished with organic solvents or aqueous solutions which dissolve the unhardened photoresist. Examples of such solvents include propylene carbonate, gamma butyrolactone, and various ester formulations. Aqueous solutions include sodium carbonate. Propylene carbonate developer is typically accomplished at from 20° to 30° C., for 3 to 5 minutes in a spray developer at 30 to 40 psi spray pressure. Sodium carbonate development is typically accomplished at 80° F. (27° C.), for 3 to 5 minutes in a spray developer at 15 to 25 psi spray pressure.
- Nickel or a nickel alloy may be electroplated or electrolessly plated onto the uncovered copper surfaces that are formed during the development of the imaged photoresist.
- The remaining photoresist, having been hardened by ultraviolet exposure as described above, is stripped from the copper layer. Solvent strip solvents may include propylene carbonate and benzyl alcohol. A preferred aqueous solvent is sodium hydroxide. Solvent stripping in propylene carbonate may be accomplished at 90° C. to 105° C. for 5 to 8 minutes in a spray stripper at 50 to 60 psi spray pressure. Aqueous stripping may be accomplished at 135° F. to 145° F. (57° C. to 63° C.) for 5 to 8 minutes in a spray stripper at 20 to 30 psi spray pressure.
- The unplated copper is microetched leaving any nickel-plated copper circuit patterns. The unplated copper is microetched with an aqueous microetch solution of potassium monopersulfate in sulfuric acid with fluoroboric acid and boric acid. Microetching may be performed in a spray etcher at 85° F. to 95° F. (29° C. to 35° C.) with a 20-30 psi spray pressure. The microetching may also be performed by immersion. The microetch rate is greater than 0.001 inches per minute (2.54 centimeters/inch).
- The following examples are intended to illustrate the present invention but are not intended to limit the scope of the invention.
- A cleaning bath for copper is prepared by dissolving potassium monopersulfate in a solution of sulfuric, boric and fluoroboric acids.
Water To volume Potassium monopersulfate 10 to 220 grams/Liter Sulfuric acid 96% by weight 2 to 3% by volume Boric acid (technical grade) 3 grams/Liter Fluoroboric acid 48% by weight 2.5 mls/Liter - Makeup Procedure for 100 U.S. Gallons (0.2642 U.S. gallons/Liter)
- 1. About 90 U.S. gallons of water are added to a mixing tank or to a process tank.
- 2. Sulfuric acid, 2-3 U.S. gallons, is added to the water and mixed well.
- 3. Potassium monopersulfate, 100 pounds (453.6 grams/pound), is added and mixed well.
- 4. Boric Acid salts, 2.5 pounds, are added and mixed to dissolve.
- 5. fluoroboric acid, 946 milliliters, are added and the bath is uniformally mixed.
-
a. Sulfuric acid 50% by weight 950 milliliters/Liter b. Boric acid 60 grams/Liter c. Fluoroboric acid 48% by weight 50 milliliters/Liter - 1. Add about 95 U.S. gallons of water to a mixing tank or to a process tank.
- 2. Add 5 U.S. gallons of the liquid additive concentrate and mix to form a uniform solution.
- 3. Add 100 pounds of potassium monopersulfate and mix to dissolve.
- In an alternative method of formulating the microetch solution described above, a concentrate composed of 30.0-50.0 grams/Liter of boric acid and 35.0-55.0 grams/Liter of fluoroboric acid is prepared without sulfuric acid. The sulfuric acid may be added separately to the microetch solution apart from the concentrate. The concentrate containing the boric acid and fluoroboric acid may be employed in the microetch solution at 6.5% to 8.5% by volume.
- A copper cleaning bath is prepared in a 100 U.S. gallon tank by dissolving 2.5 U.S. gallons of sulfuric acid 96% by weight in 100 U.S. gallons of water. 100 pounds (453.6 grams/pound) of potassium monopersulfate are added and dissolved with mixing. The bath is used in a cleaning process to prepare copper circuits on a panel for the application of solder in a hot air solder leveling process. Panels are processed through the bath and through the HASL machine. As the copper concentration increases in the bath from copper removal from circuits to the range of 12-15 grams/Liter, blue crystals of copper salts may be seen on the parts of the HASL machine where solution evaporates leaving behind dry salts. At this time, rinsing of the cleaned parts becomes more difficult due to the salt formation, and the bath must be pumped out and treated to remove and recover the copper. A new bath is made and the cycle is repeated. In this example, 8,000 square-feet of copper containing panels are processed through the cleaning bath before the bath is dumped.
- A cleaning bath is prepared in a 100 U.S. gallon tank by the addition of 95 U.S. gallons of water and 5 U.S. gallons of the liquid additive concentrate described in Example 1 above followed by dissolving 100 pounds of potassium monopersulfate. The bath is used in a process for cleaning copper circuits prior to the application of solder in the HASL process of Example 2. Panels are processed through the copper cleaner and the HASL process and observations are made for the formation of copper salts above the level of the bath. The copper concentration is more than 40 grams/Liter before the dark blue solution began to form blue salts around the level of the bath. This corresponds to 24,000 square-feet of copper-containing panels or more than 3 times the yield of Example 2 before the bath is dumped, treated for disposal and the copper recovered. The operating cost of Example 3 is about ⅓ that of the process in Example 2. Thus, the persulfate composition of the present invention as disclosed in Example 1 is an improved persulfate microetch solution.
Claims (20)
1. A composition comprising a persulfate, a fluorine containing acid, and boric acid or a salt of boric acid or mixtures thereof.
2. The composition of claim 1 , wherein the persulfate comprises sodium monopersulfate, potassium monopersulfate, or mixtures thererof.
3. The composition of claim 1 , wherein the fluorine containing acid comprises hydrofluoric acid, fluoroboric acid, fluorosilic acid, or mixtures thereof.
4. The composition of claim 1 , wherein the salts of boric acid comprise lithium, sodium, potassium salts of boric acid, or mixtures thereof.
5. The composition of claim 1 , further comprising an additional inorganic acid.
6. The composition of claim 5 , wherein the additional inorganic acid comprises sulfuric acid, phosphoric acid, phosphorous acid, or mixtures thererof.
7. The composition of claim 1 , further comprising one or more adjuvants.
8. A composition comprising potassium monopersulfate, fluoroboric acid, boric acid and sulfuric acid.
9. A method of preparing a composition comprising:
a) providing an aqueous solution of a persulfate;
b) mixing a concentrate comprising boric acid or a salt of boric acid and a fluoride containing acid with the aqueous solution of the persulfate to form a first mixture; and
c) mixing an additional inorganic acid with the first mixture to form a stable second mixture.
10. The method of claim 9 , wherein the persulfate comprises an alkali monopersulfate.
11. The method of claim 9 , wherein the fluoride containing acid comprises fluoroboric acid.
12. The method of claim 9 , wherein the additional inorganic acid is sulfuric acid.
13. The method of claim 9 , further comprising the step of adding at least one adjuvant to the stable second mixture.
14. A method of microetching a metal comprsing: contacting a surface of a metal with a microetch solution comprising a persulfate, boric acid or a salt of boric acid, a fluoride containing acid and an additional inorganic acid to remove a portion of the surface of the metal.
15. The method of claim 14 , wherein the persulfate comprises an alkali monopersulfate.
16. The method of claim 14 , wherein the fluorine containing acid comprises fluoroboric acid.
17. The method of claim 14 , wherein the metal comprises copper.
18. the method of claim 14 , wherein the microetching is performed at a temperature of 80° F. to 100° F.
19. The method of claim 17 , wherein the copper saturation and crystallization concentration in the microetch solution is greater than 40 grams/Liter.
20. The method of claim 14 , wherein the metal is part of a printed circuit board.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/658,702 US20040112869A1 (en) | 2002-09-09 | 2003-09-09 | Cleaning composition |
US11/191,796 US20050261152A1 (en) | 2002-09-09 | 2005-07-28 | Cleaning composition |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US40923902P | 2002-09-09 | 2002-09-09 | |
US10/658,702 US20040112869A1 (en) | 2002-09-09 | 2003-09-09 | Cleaning composition |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/191,796 Division US20050261152A1 (en) | 2002-09-09 | 2005-07-28 | Cleaning composition |
Publications (1)
Publication Number | Publication Date |
---|---|
US20040112869A1 true US20040112869A1 (en) | 2004-06-17 |
Family
ID=31716003
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/658,702 Abandoned US20040112869A1 (en) | 2002-09-09 | 2003-09-09 | Cleaning composition |
US11/191,796 Abandoned US20050261152A1 (en) | 2002-09-09 | 2005-07-28 | Cleaning composition |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/191,796 Abandoned US20050261152A1 (en) | 2002-09-09 | 2005-07-28 | Cleaning composition |
Country Status (5)
Country | Link |
---|---|
US (2) | US20040112869A1 (en) |
EP (1) | EP1396557A1 (en) |
JP (1) | JP2004149770A (en) |
CN (1) | CN1500912A (en) |
TW (1) | TW200417628A (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20070278182A1 (en) * | 2006-06-02 | 2007-12-06 | Robert Jeffrey Durante | Potassium monopersulfate solutions |
US20080199391A1 (en) * | 2007-02-20 | 2008-08-21 | Advanced Chip Engineering Technology Inc. | Method for circuits inspection and the method of the same |
US20100065530A1 (en) * | 2007-02-06 | 2010-03-18 | Advanced Technology Materials, Inc | COMPOSITION AND PROCESS FOR THE SELECTIVE REMOVE OF TiSiN |
Families Citing this family (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7291565B2 (en) * | 2005-02-15 | 2007-11-06 | Tokyo Electron Limited | Method and system for treating a substrate with a high pressure fluid using fluorosilicic acid |
KR101310310B1 (en) * | 2007-03-15 | 2013-09-23 | 주식회사 동진쎄미켐 | Etchant for thin film transistor-liquid crystal displays |
JP5105081B2 (en) * | 2008-04-08 | 2012-12-19 | 栗田工業株式会社 | Functional solution supply system and functional solution supply method |
JP5136339B2 (en) * | 2008-09-30 | 2013-02-06 | 東ソー株式会社 | Etching composition and etching method using the same |
CN102977889A (en) * | 2011-09-02 | 2013-03-20 | 东友精细化工有限公司 | Etching solution composition for metal oxide layer containing gallium |
US9029268B2 (en) * | 2012-11-21 | 2015-05-12 | Dynaloy, Llc | Process for etching metals |
EP3019635B1 (en) | 2013-07-08 | 2020-07-01 | Alpha Assembly Solutions Inc. | Methods for recovering or removing tin and/or tin alloy |
EP3080240A4 (en) | 2013-12-11 | 2017-07-19 | FujiFilm Electronic Materials USA, Inc. | Cleaning formulation for removing residues on surfaces |
CN110049637B (en) * | 2019-05-22 | 2020-11-06 | 昆山欧贝达电子科技有限公司 | Brown oxidation treatment process of PCB substrate |
Citations (20)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3137600A (en) * | 1960-09-12 | 1964-06-16 | Fmc Corp | Dissolution of copper |
US3269881A (en) * | 1963-12-30 | 1966-08-30 | Allied Chem | Hydrogen peroxide etching of copper in manufacture of printed circuits |
US4130455A (en) * | 1977-11-08 | 1978-12-19 | Dart Industries Inc. | Dissolution of metals-utilizing H2 O2 -H2 SO4 -thiosulfate etchant |
US4256602A (en) * | 1978-12-01 | 1981-03-17 | Pennwalt Corporation | Fluoroborate complex composition and method for cleaning aluminum at low temperatures |
US4349411A (en) * | 1981-10-05 | 1982-09-14 | Bell Telephone Laboratories, Incorporated | Etch procedure for aluminum alloy |
US4378270A (en) * | 1981-10-29 | 1983-03-29 | Learonal, Inc. | Method of etching circuit boards and recovering copper from the spent etch solutions |
US4502925A (en) * | 1984-06-11 | 1985-03-05 | American Hoechst Corporation | Process for aluminum surface preparation |
US4695348A (en) * | 1986-09-15 | 1987-09-22 | Psi Star | Copper etching process and product |
US5259979A (en) * | 1993-01-13 | 1993-11-09 | Oliver Sales Company | Process for regeneration of cleaning compounds |
US5296268A (en) * | 1991-09-03 | 1994-03-22 | Shipley Company Inc. | Pretreatment process of tin lead plating |
US5669980A (en) * | 1995-03-24 | 1997-09-23 | Atotech Usa, Inc. | Aluminum desmut composition and process |
US5958288A (en) * | 1996-11-26 | 1999-09-28 | Cabot Corporation | Composition and slurry useful for metal CMP |
US6001264A (en) * | 1995-08-21 | 1999-12-14 | Kurita Water Industries Ltd. | Water-treating agent and method for treating water |
US6086779A (en) * | 1999-03-01 | 2000-07-11 | Mcgean-Rohco, Inc. | Copper etching compositions and method for etching copper |
US6156221A (en) * | 1998-10-02 | 2000-12-05 | International Business Machines Corporation | Copper etching compositions, processes and products derived therefrom |
US6284309B1 (en) * | 1997-12-19 | 2001-09-04 | Atotech Deutschland Gmbh | Method of producing copper surfaces for improved bonding, compositions used therein and articles made therefrom |
US20020000382A1 (en) * | 1999-12-15 | 2002-01-03 | Shipley Company, L.L.C. Of Marlborough | Seed layer repair method |
US6383723B1 (en) * | 1998-08-28 | 2002-05-07 | Micron Technology, Inc. | Method to clean substrate and improve photoresist profile |
US6407047B1 (en) * | 2000-02-16 | 2002-06-18 | Atotech Deutschland Gmbh | Composition for desmutting aluminum |
US6444140B2 (en) * | 1999-03-17 | 2002-09-03 | Morton International Inc. | Micro-etch solution for producing metal surface topography |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US644140A (en) * | 1899-12-16 | 1900-02-27 | Nathaniel Mccaul Lent | Overflow-alarm. |
JPS5224508B2 (en) * | 1973-11-19 | 1977-07-01 | Tokai Electro Chemical Co | |
JPS57164984A (en) * | 1981-04-06 | 1982-10-09 | Metsuku Kk | Exfoliating solution for tin or tin alloy |
DE3469041D1 (en) * | 1983-10-06 | 1988-03-03 | Olin Corp | Process for cleaning copper base materials and regenerating the cleaning solution |
US5393447A (en) * | 1993-07-09 | 1995-02-28 | Henkel Corporation | Composition and process for desmutting and deoxidizing without smutting |
US6248309B1 (en) * | 1997-04-04 | 2001-06-19 | Optiva Corporation | Gums containing antimicrobial agents |
JP2000064067A (en) * | 1998-06-09 | 2000-02-29 | Ebara Densan Ltd | Etching solution and roughening treatment of copper surface |
-
2003
- 2003-09-08 TW TW092124711A patent/TW200417628A/en unknown
- 2003-09-09 US US10/658,702 patent/US20040112869A1/en not_active Abandoned
- 2003-09-09 JP JP2003316784A patent/JP2004149770A/en active Pending
- 2003-09-09 EP EP03255603A patent/EP1396557A1/en not_active Withdrawn
- 2003-09-09 CN CNA031648967A patent/CN1500912A/en active Pending
-
2005
- 2005-07-28 US US11/191,796 patent/US20050261152A1/en not_active Abandoned
Patent Citations (20)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3137600A (en) * | 1960-09-12 | 1964-06-16 | Fmc Corp | Dissolution of copper |
US3269881A (en) * | 1963-12-30 | 1966-08-30 | Allied Chem | Hydrogen peroxide etching of copper in manufacture of printed circuits |
US4130455A (en) * | 1977-11-08 | 1978-12-19 | Dart Industries Inc. | Dissolution of metals-utilizing H2 O2 -H2 SO4 -thiosulfate etchant |
US4256602A (en) * | 1978-12-01 | 1981-03-17 | Pennwalt Corporation | Fluoroborate complex composition and method for cleaning aluminum at low temperatures |
US4349411A (en) * | 1981-10-05 | 1982-09-14 | Bell Telephone Laboratories, Incorporated | Etch procedure for aluminum alloy |
US4378270A (en) * | 1981-10-29 | 1983-03-29 | Learonal, Inc. | Method of etching circuit boards and recovering copper from the spent etch solutions |
US4502925A (en) * | 1984-06-11 | 1985-03-05 | American Hoechst Corporation | Process for aluminum surface preparation |
US4695348A (en) * | 1986-09-15 | 1987-09-22 | Psi Star | Copper etching process and product |
US5296268A (en) * | 1991-09-03 | 1994-03-22 | Shipley Company Inc. | Pretreatment process of tin lead plating |
US5259979A (en) * | 1993-01-13 | 1993-11-09 | Oliver Sales Company | Process for regeneration of cleaning compounds |
US5669980A (en) * | 1995-03-24 | 1997-09-23 | Atotech Usa, Inc. | Aluminum desmut composition and process |
US6001264A (en) * | 1995-08-21 | 1999-12-14 | Kurita Water Industries Ltd. | Water-treating agent and method for treating water |
US5958288A (en) * | 1996-11-26 | 1999-09-28 | Cabot Corporation | Composition and slurry useful for metal CMP |
US6284309B1 (en) * | 1997-12-19 | 2001-09-04 | Atotech Deutschland Gmbh | Method of producing copper surfaces for improved bonding, compositions used therein and articles made therefrom |
US6383723B1 (en) * | 1998-08-28 | 2002-05-07 | Micron Technology, Inc. | Method to clean substrate and improve photoresist profile |
US6156221A (en) * | 1998-10-02 | 2000-12-05 | International Business Machines Corporation | Copper etching compositions, processes and products derived therefrom |
US6086779A (en) * | 1999-03-01 | 2000-07-11 | Mcgean-Rohco, Inc. | Copper etching compositions and method for etching copper |
US6444140B2 (en) * | 1999-03-17 | 2002-09-03 | Morton International Inc. | Micro-etch solution for producing metal surface topography |
US20020000382A1 (en) * | 1999-12-15 | 2002-01-03 | Shipley Company, L.L.C. Of Marlborough | Seed layer repair method |
US6407047B1 (en) * | 2000-02-16 | 2002-06-18 | Atotech Deutschland Gmbh | Composition for desmutting aluminum |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20070278182A1 (en) * | 2006-06-02 | 2007-12-06 | Robert Jeffrey Durante | Potassium monopersulfate solutions |
US7442323B2 (en) * | 2006-06-02 | 2008-10-28 | E. I. Du Pont De Nemours And Company | Potassium monopersulfate solutions |
US20100065530A1 (en) * | 2007-02-06 | 2010-03-18 | Advanced Technology Materials, Inc | COMPOSITION AND PROCESS FOR THE SELECTIVE REMOVE OF TiSiN |
US20080199391A1 (en) * | 2007-02-20 | 2008-08-21 | Advanced Chip Engineering Technology Inc. | Method for circuits inspection and the method of the same |
US7534632B2 (en) * | 2007-02-20 | 2009-05-19 | Advanced Chip Engineering Technology Inc. | Method for circuits inspection and method of the same |
Also Published As
Publication number | Publication date |
---|---|
TW200417628A (en) | 2004-09-16 |
US20050261152A1 (en) | 2005-11-24 |
CN1500912A (en) | 2004-06-02 |
JP2004149770A (en) | 2004-05-27 |
EP1396557A1 (en) | 2004-03-10 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US20050261152A1 (en) | Cleaning composition | |
US6521328B1 (en) | Copper etching compositions and products derived therefrom | |
US4378270A (en) | Method of etching circuit boards and recovering copper from the spent etch solutions | |
JP4687852B2 (en) | Surface treatment agent for copper and copper alloys | |
KR20100110745A (en) | Etchant composition and method | |
DE10066028C2 (en) | Copper substrate with roughened surfaces | |
US6830627B1 (en) | Copper cleaning compositions, processes and products derived therefrom | |
US20040101624A1 (en) | Treating metal surfaces with a modified oxide replacement composition | |
EP0397327B1 (en) | Process for dissolving tin and tin alloys | |
JPH01240683A (en) | Composition of etching solution for copper and etching method | |
US6129858A (en) | Etching solution | |
JPH116083A (en) | Dissolving liquid for copper or copper alloy, its production, etching, chemical polishing and forming method of copper and copper alloy, and production of printed circuit board | |
US20050098538A1 (en) | Methods of cleaning copper surfaces in the manufacture of printed circuit boards | |
JP4431860B2 (en) | Surface treatment agent for copper and copper alloys | |
JPH1096088A (en) | Etchant, and surface roughening method for copper | |
JPS5873775A (en) | Soft etching agent for copper | |
KR20170061096A (en) | Method and apparatus for separating silver from etching waste solution | |
EP0661388B1 (en) | Chemical etchant for palladium | |
JPH0542513B2 (en) | ||
JP3124512B2 (en) | Etching solution for etching resist | |
JPH10310881A (en) | Method for etching copper-base metallic material | |
JP2004218021A (en) | Surface treatment agent for microetching copper and copper alloy, and roughening treatment method for surface of copper and copper alloy | |
JPH07278846A (en) | Removing solution for tin, tin alloy, nickel or nickel alloy | |
JPH06322548A (en) | Chemical copper plating liquid, chemical copper plating method and production of wiring board | |
JPH04157167A (en) | Pretreating solution for electroless plating |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: SHIPLEY COMPANY, L.L.C., MASSACHUSETTS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:CARTER, JOHN G.;FELLMAN, JACK D.;KNOP, JACEK M.;AND OTHERS;REEL/FRAME:014998/0736;SIGNING DATES FROM 20031204 TO 20040201 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |