Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B08—CLEANING
  • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
  • B08B3/00—Cleaning by methods involving the use or presence of liquid or steam
  • B08B3/04—Cleaning involving contact with liquid
  • B08B3/08—Cleaning involving contact with liquid the liquid having chemical or dissolving effect
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
  • C11D7/50—Solvents
  • C11D7/5004—Organic solvents
  • C11D7/5018—Halogenated solvents
• • 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
  • C23G5/00—Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents
  • C23G5/02—Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents using organic solvents
  • C23G5/028—Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents using organic solvents containing halogenated hydrocarbons
  • C23G5/02806—Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents using organic solvents containing halogenated hydrocarbons containing only chlorine as halogen atom
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
  • C11D7/22—Organic compounds
  • C11D7/26—Organic compounds containing oxygen
  • C11D7/261—Alcohols; Phenols
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
  • C11D7/22—Organic compounds
  • C11D7/28—Organic compounds containing halogen

Definitions

• chlorinated hydrocarbons especially 1,1,1-trichloroethane (methylchloroform) will remove the nonionic components of the rosin flux solder aids better than the aforementioned fluorochlorocarbon blend.
• stable 1,1,1-trichloroethane (methylchloroform) solvent compositions in combination with from 0.5 to less than 2 percent by volume of methanol and from about 3 to about 10 percent by volume of at least one alcohol having from 2 to 5 carbon atoms have proven to be superior flux removal solvents. These compositions also have no flash point.
• Coupons of electronic circuit board base material measuring 1" x 1" x 1/16" (25.4 mm x 25.4 mm x 1.6 mm) were cleaned by immersion in two clean baths of 75 volume percent 2-propanol (isopropyl alcohol) and 25 volume percent water, agitated by an ultrasonic vibrator. The clean coupons were placed in a nitrogen dry box until used.
• Each clean coupon was removed from the dry box and immediately immersed horizontally into an Alpha 711-35 MIL flux for five minutes.
• the Alpha 711-35 MIL flux is widely used by circuit board manufacturers, and is well known to those skilled in the art.
• the coupons were then hung horizontally to dry for five minutes.
• the coupon was heated in a horizontal position in an oven at 250°C for 15 seconds to simulate actual use conditions. After heating, the coupon was again hung in a nitrogen dry box until used in the cleaning experiments.
• a flux coated coupon taken from the dry box was hung from a clip and (1) introduced into a vapor zone of the flux removal solvent formulation for thirty (30) seconds, (2) immersed in the boiling solvent for thirty (30) seconds, (3) raised above the vapor zone into the free board area above the vapor zone for thirty (30) seconds, then (4) back into the vapor zone for a final thirty (30) seconds and (5) removed to a hanger to dry.
• Each coupon after drying was tested for cleanliness by immersing the coupon in 40 ml of a pure solvent consisting of an admixture of 2-propanol (isopropyl alcohol) and water, 75/25 volume percent, respectively, while the solvent was subjected to ultrasonic vibration for five (5) minutes.
• the resistivity of the aqueous alcohol solution was measured using a clean 1 mm conductivity bridge for each measurement. The mean result of several measurements for each of the enumerated formulations was obtained. The higher the resistivity value, the more effective is the removal of the ionic flux residues.
• the test consisted of placing aluminum (Al 2024) shavings in a flask containing the liquid solvent blend.
• a condenser was attached to the flask and the solvent heated to boiling and refluxed by the condenser for a period of seven days, during which time observations were made of the shavings. If no corrosion of the aluminum was observed by the end of seven days, the blend was considered to have passed the test.
• the flash point of each blend was also determined. (The method used was ASTM-92 known as the Cleveland Open Cup flash point method.) If the blend had a flash point, it was considered to have failed. No observable flash point indicates the solvent passed, or was acceptable. The results of flash point and corrosion tests are given in Table I, failed and passed being indicated by F and P, respectively.
• Comparative Examples 7-13 employ 10 percent of several different alcohols with the inhibited of Comparative Example 1.
• Comparative Examples 1-13 are comparative in nature and do not fall within the scope of the invention.
• Comparative Example 1 The inhibited methylchloroform of Comparative Example 1 is not effective in removing ionic components of the flux.
• Comparative Examples 2 and 3 demonstrate the present state of the art in cleaning ionic residues with commercially available blends which do not have a flash point. It is apparent that the fluorochlorocarbon blend is more effective than the butanol-1,1,1-trichloroethane blend. It is also apparent from Examples 4-13 that a single alcohol blended with 1,1,1-trichloroethane will not yield a formulation which will give comparable results to the fluorinated blend and still have no flash point. Comparative Examples 4 and 5 show that 1 percent methanol in 1,1,1-trichloroethane gives no flash point whereas 2 percent methanol has a flash point.
• a number of stabilized 1,1,1-trichloroethane (Comparative Example 1) flux-removal compositions containing various amounts of methanol together with other alcohols were tested on the same flux as above in accordance with the above described procedures. Results are shown in Table II as Examples 14-35. These examples show that some 1,1,1-trichloroethane blends with methanol, 2-butanol and/or 2-methyl-3-butyn-2-ol which have no flash point unexpectedly have better ionic residual flux removal performance than the fluorochlorocarbon blend of Comparative Example 2.
• the preferred blends contain about 1 percent methanol and about 6 percent of 2-butanol and/or 2-methyl-3-butyn-2-ol.
• the blends containing 0.5 percent methanol are slightly inadequate in their ionic residual flux removal and the blends approaching 2 percent methanol are too close to the undesirable flash point region.
• the volume of methanol when the volume of methanol is comparatively low the volume of the other alcohol component or mixture needs to be higher in order to effect the removal of ionic components.
• the methanol volume approaches 2 percent, the other component can be present in minimal quantities. Two percent or more of methanol gives a product which has a flash point and thus is outside the scope of the invention.
• compositions as do all 1,1,1-trichloroethane compositions which may be employed in contact with metals, especially aluminum, should be stabilized to be commercially practical. Any of a number of compounds are useful as stabilizers, including diethylene ether (1,4-dioxane), dioxolanes, nitroalkanes, 1,2-butylene oxide and the like. These are well known to the art-skilled and have substantially no adverse effect on the flux removal properties. Since the known stabilized 1,1,1-trichloroethane compositions do not completely remove the ionic flux components, it is necessary to add other solvents to them to provide for more complete removal of these ionics. The present invention provides such compositions which are shown in Table II and described in the above Summary of the Invention.
• Table III again shows the poor performance of stabilized 1,1,1-trichloroethane alone.
• the alcohol blends containing no methanol also show low effectiveness as compared to the methanol blends of the present invention. It is noted that since Alpha 711 flux contains 50 percent solids as opposed to 35 percent solids for 711-35 MIL it is more difficult to clean using the same set of conditions, this is reflected in the lower specific resistance values obtained.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Organic Chemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Metallurgy (AREA)
• Mechanical Engineering (AREA)
• Materials Engineering (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Wood Science & Technology (AREA)
• Detergent Compositions (AREA)
• Treating Waste Gases (AREA)
• Cleaning Or Drying Semiconductors (AREA)
• Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
• Manufacturing Of Printed Wiring (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

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Family Applications (1)

Country Status (6)

Cited By (2)

Citations (10)

• 1983
  • 1983-11-08 FI FI834090A patent/FI834090A/fi not_active Application Discontinuation
  • 1983-11-08 EP EP83111161A patent/EP0108422A1/en not_active Withdrawn
  • 1983-11-08 BR BR8306283A patent/BR8306283A/pt unknown
  • 1983-11-08 KR KR1019830005291A patent/KR840006450A/ko not_active Application Discontinuation
  • 1983-11-08 NO NO834067A patent/NO834067L/no unknown
  • 1983-11-08 JP JP58208434A patent/JPS59113189A/ja active Pending

Patent Citations (10)

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