TW496789B - Cleaning processes using hydrofluorocarbons and/or hydrochlorofluorocarbon compounds - Google Patents

Abstract

Disclosed are methods of cleaning articles of manufacture using hydrofluorocarbon and hydrochlorofluorocarbon fluids. The methods comprise generally the steps of (a) providing a hydrofluorocarbon and/or hydrochlorofluorocarbon fluid in liquid or supercritical state; (b) contacting an article of manufacture with said fluid; and (c) removing substantially all of said fluid from said article of manufacture.

Description

V. Description of the invention (1) Scope of the invention t: Generally, the boundary between hydrofluorocarbons and argon fluorocarbons in the cleaning method is used, and the present invention is about certain subcritical states and transcendences | A method of breaking a rat's fluorine and / or hydrogen fluoride to clear a printed circuit board. The machine fires all kinds of clothing and objects, especially the background B. It is exaggerated as follows: t two brush circuit boards' * soldering flux for surface mounting components and other similar electronic components is a kind of turpentine (the second activator is typically ion / m This product does not remove diamine gasification amine from the surface of the metal. The purpose of the flux is to heat the flux to a more acceptable temperature during the soldering operation, and the temperature of the molten tin / lead flux), and "Baking on == Guangben may be right for flux residue; ^ έ # t"; °. When this soldering gas is used, the ion material must be removed. When exposed to moisture. Ke Li is particularly suspicious, because it becomes mobile and conductive in the near past-to-be, using chlorofluorocarbon (ΐ) to solder circuit boards for soldering materials. This is economical. However, because of the understanding of CFC, _Yuhuan 1 is not effective and the creators are transferred to water-based cleaners. Such cleaners are charged at V 5 for 5 days, because they require strong energy to make 222 == > 糸, but they are not liquid. And supercritical oxygen / :: = after disposal. Alternatives. However, due to :::, ;; mention = for aqueous cleaning. One such disadvantage is that the use of carbon dioxide requires non-carbon /, must ft — This 496789 V. Description of the invention (2)-Use of more expensive pressurizing equipment. Another disadvantage is that carbon dioxide is not effective for cleaning this polar substrate. Hydrofluoric cracking (Η FC's) is a more environmentally friendly alternative to CFC's. However, it was proposed as an ineffective cleaner in the technology. For example, Li Blank (1 ^ 1) 1 &: 1 (:) noticed that "Although HFC's do not contain gas, its high vapor pressure And low solubility make it a poor cleaning agent. "[The elution of cleaning solvents, precise cleaning (T he Evolution of Cleaning Solvents, Precision Cleaning), May 1997, page 14.] This is supported by Kanegsberg ^ !, which suggests that HFC's "on the one hand are used as other solvents The carrier, on the one hand, is used as a rinsing agent. The number of Kauri Bntanol (KB) of HFC, s is about 10, and it has a little or no dissolving power for most of the pollutants of interest. "[[ Precision Cleaning Without Ozone Depleting Chemicals, Chemical & Industry, October 1996, p. 788.] Understanding these and other disadvantages of prior art, this book The inventors are aware of the need for a novel, effective, and more desirable method for the clean manufacturing of objects such as printed circuit boards. These and other objects are achieved by the present invention as described below. DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS The present invention relates to Various methods of cleaning articles, but especially printed circuit boards that use hydrofluorocarbon ("HFC") and hydrofluorocarbon ("HCFC") compounds' or compounds of HFC and HCFC compounds. The inventors surprisingly found that are some single HFC s and single JCFC 's or in combination with a small amount of a polar solvent, in the liquid shank

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V. Description of the invention (3) Super-S product base >> 1, because _-this method is less expensive, and its performance is dramatically better than carbon dioxide. HFC, s mouth HCFC, s Heng # 广 广 ^ Low pressure and critical pressure are lower than those required for carbon dioxide equipment. ^

The operating pressure will be lower and the equipment used will be expensive. This is a heavy & AA spoon ’because of a barrier to using supercritical technology. The high cost of high pressure equipment.

^ ^ In a specific embodiment of the present invention, the manufacturing method of the article containing contamination on the surface is as follows: (a) providing a hydrogen product such as a supercritical fluid; (^) contaminating the manufactured article at least The surface is in contact with the supercritical wind, 51 body, and (c) almost completely removes all of the super-L-boundary hydrohalocarbon fluid from the manufactured article. Hydrohalocarbon as used herein means any compound of HCFC. The method of the present invention can be used to clean a variety of manufactured objects, including a printed circuit board including a circuit board with a surface mounting device, and a circle of Shi Xi 1 ° For Shi Xi wafer, the present invention It can be used to effectively clean and remove mature and uncured photoresist, which is deposited on the wafer when a totem for manufacturing a computer wafer is placed thereon. Furthermore, the method of the present invention is particularly applicable to cleaning printed circuit boards.

As used herein, "supercritical fluid" generally refers to a supercritical fluid, which includes at least one HFC or HCFC compound, and also refers to an HFC or HCFC compound that is liquid and has a boiling point below about 16 ° c at atmospheric pressure. The present inventors believe that for many specific embodiments of the present invention, such liquid fluids act on certain fluids similar to those in the super g range. For the purposes of the present invention, 'any supercritical fluid, which includes a single HFC or HCFC fluid or a mixture of HFC and / or HCFC fluids, and any HFC or HCFC fluid with other

Page 7 496789 V. Description of the invention (4) The mixture of materials and / or additives will be a "supercritical fluid". For the purpose of the present invention, any liquid fluid whose boiling point at atmospheric pressure is lower than about 16 ° C, A single HFC or HCF fluid or a mixture of HFC and / or HCFC, and a mixture of HFC or HCFC fluid with other materials and / or additives will be a "supercritical fluid". Various H F C 's or H C F C' s can be used in the method of the present invention to provide a supercritical fluid. Suitable HFC's include, for example, difluoromethane (,, R-32π), pentafluoroethane (nR-125 "), tetrafluoroethane isomers (,, R-134, 1anR-134an), Trifluoromethane (" Erliang-2 3 "), trifluoroethane isomers ("R 1 1 4 3π and 1

"R-143a"), pentafluoroethane (" R-125 ") and pentafluoropropane such as, 'R-2 4 5 fa," R-2 4 5 e an, n R ~ 2 4 5 c aπ, and MR-2 4 5 c b "), etc. Suitable HCFC's include gas difluoromethane ("R_22 "), tetrafluorochloroethane, R-124n) and so on. In some preferred embodiments, the HFC used in the present invention is R-2 3 or R-32. In other preferred embodiments, the HCFC used in the present invention is R-22 or R-124. The HFC and HCFC of the present invention can be used alone or blended with each other. When using a mixture ’, it contains the common or common Buddha or constant; For example, such mixtures are described in US Patent No. 4,9, including azeotropes of R-32 and R-125, which are incorporated herein. 4

Other materials can be added to the hydrogen-containing good number. These materials include: a straight chain force of 嶋 to about 8 carbons. Alcohols, such as acetol, acetonitrile, = n depleted chain and if will be sub-C, propyl alcohol and butanol; linear, branched ^ long-order alkane, such as aerosol; dioxy ψ ^ _ and bond and糸 糸 496789 V. Description of the invention (5) -----—__, compounds of sulfur and saucer; and fragrant — often, this 4b # # γ stomach & Tong-Li Ma υ · 1 weight I% to about 10% by weight. A = In the specific embodiment, it will be about. .1% to 10% by weight. The applicants found that adding this amount of “A” is a messy and successful one. The supercritical fluid cleaning effectiveness of the medium is provided. For example] the dicarbohalocarbon compounds are extracted by 0.5% by weight of methanol and mainly by [12 see according to the present invention The cleaning efficiency will be approximately β times greater than that of pure R-125. ° ^ Use of fluids together, = known additives for solvent cleaning applications / 1 Appropriate additives include: stabilizers, such as those used in children of the present invention Nitroalkanes; acid neutralizers, such as & radicals = two having about 1 to about 5 carbon atoms, facial agents, such as ionic or nonionic circles ::: epoxides; and non-rats Surfactants. Existing amounts of additives, biocides, including fluorinated about 5% by weight, preferably about 0.1 to about 1% by weight. Suspended from about 0.1% by weight to some specific embodiments of the present invention Provide fluid receiving step HFC and / or HCFC- sufficient to form a super-prosthetic clothing (=) including HFC, s, HCFC, s, other village environments as will be included, often, as described herein. Commercially available Obtained. According to certain embodiments, the 'and additives are all in HFC or HCFC fluid as supercritical fluid Applicable in the present invention

^^ HFC ^ HCFC For specific embodiments with a boiling point higher than about 16 ° F, the environment is sufficient to make the fluid in a supercritical state. For super ^ evil wind 1 ^ carbon connection, the temperature and / or pressure of the fluid can be increased to high; ^ state fluid ’η is at the critical temperature and near —

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496789 V. Description of the invention (6) Boundary pressure. For example, Fig. 1 is a block diagram of an apparatus for use in the present invention in which a fluid can be subjected to an environment sufficient to form a supercritical fluid. In the figure, the HFC / HCFC fluid container 11 is connected to the drum 12. The drum 12 is connected to the chamber 1 3 containing the object 14 to be cleaned. According to this method, the H {? C ^ HCFC fluid held in the container, not shown, passes through the drum 12, where the fluid pressure and / or temperature is raised to a point sufficient to form a supercritical fluid. The supercritical fluid then passes through the chamber 13 to clean the contents contained therein. According to the present invention, this method and other known methods can be used to provide a supercritical hydrogen-containing halocarbon fluid, after which the contaminated C-making article is exposed to the supercritical fluid. Those skilled in the art will be able to determine the environment in which H F C and H C F C compounds must be accepted to form a supercritical fluid according to the present invention. The temperature will depend on some or both of H F c, s and / or HCFC 's and on pressure. Generally, the supply of supercritical% is based on maintaining the HFC or HCFC at a temperature of about-= 2 0 t, and even more preferably about 15 ° C to about 130 t according to the present invention. In some of the more specific embodiments, the pressure at which the supercritical fluid is provided is typically from about 25 to about 10,000 psia, and more preferably from about 100 to 3,500 psia. According to the above disclosure, the skilled artist will be able to provide supercritical fluids according to the present invention without undue experimentation. According to a preferred embodiment of the present invention, the contacting step (b) includes covering at least a part of the contaminated surface in the manufacturing object with a critical fluid, and dissolving a part of the pollutants from the surface in the supercritical fluid to remove Flow ;; cause contamination to be removed from the contact portion of the manufactured article. Any known method for covering at least part of a contaminated surface of an article of manufacture can be used in the present invention, including, for example, immersing the article in a super-critical stream.

Page 10 496789 V. Description of the invention (7) In private ‘spray objects and so on. In a preferred embodiment of the present invention, the coating method is dipping.

Any known method for immersing a manufactured article in a supercritical fluid can be used in the present invention, including, in particular, immersing a manufactured article in a supercritical fluid stream. For example, according to a preferred embodiment of the present invention, the cleaning device illustrated by the block diagram in Fig. I can be used to immerse a manufactured article in a supercritical fluid machine. In FIG. 1 ′, a supercritical fluid flows into the chamber 丨 3 by passing the or HCFC fluid through the cartridge 12, exits the expansion valve 5, and enters the low-pressure sound receiving container 16. When :: is introduced into the chamber 3, the supercritical fluid expands to fill the f ,. Therefore, the object ′ 4 to be held in the chamber 13 is immersed in the supercritical fluid flow as it flows from the cylinder 丨 2 to the container 16 through the valve Γ5. Or f 'manufactured article can be immersed by "pressure pulse" as described in Wetmoore et al. U.S. Patent No. 5,5 1,4,220. 4 patents are incorporated into This article is for reference. Generally, a pressure pulse involves contacting an object with a fluid in a supercritical or f supercritical environment, and periodically pressurizing the supercritical fluid to a higher level, after which the pressure is reduced back to the original level. Those skilled in the art will immediately be able to use this pressure in the present invention without undue experimentation.

In a specific embodiment of the invention in which the supercritical fluid is a liquid fluid, the article of manufacture may be impregnated by immersing at least a portion of the article of manufacture in the liquid fluid. The artist will immediately be able to use this pressure in the present invention without undue experimentation. The entrenched person will understand the environment in which the object is immersed in a supercritical fluid flow, including flow rate, temperature, pressure, and time, which will vary depending on many factors, including the HFC or HCFC fluid used. For example, in a gHCFC fluid age

Page 11 496789 V. Description of the invention (8) In the preferred embodiment including R-22, at a temperature of about 25 ° C and a pressure of about 151 _ psia, remove 100% of the softness on the printed circuit board. Welding Aid:!: Capacitor. In addition, in certain preferred embodiments of certain HFC fluids including R-32, 90% of the solder on the printed circuit board is removed at a temperature of about 100 ° C and a pressure of about 120 psia. Flux. According to this disclosure, those skilled in the art will immediately be able to optimize the immersion environment used in the present invention without undue experimentation. The step (c) is preferably removed to evaporate the supercritical fluid. According to a preferred embodiment, the evaporation step includes changing the pressure and / or temperature of the supercritical fluid so that the fluid is transformed into a gaseous state. As those skilled in the art will understand, by changing the pressure 'temperature or both pressure and temperature, a supercritical fluid can be immediately transformed into a gaseous state' so that the fluid is no longer in a supercritical state. In addition, the fluid of the present invention (a fluid having an atmospheric boiling point of about 6 t or lower) can usually be converted into a gas by reducing the pressure or increasing the temperature. Contaminants therein are deposited and collected in a container 16. Based on the above disclosure, this person will immediately be able to evaporate and remove supercritical fluids in accordance with the present invention. After the supercritical fluid is steamed and the pollutants are removed according to the present invention, the surrounding environment of the supercritical fluid can be changed to cause pollutants dissolved in the supercritical fluid to sink out of the solution. Therefore, in certain preferred embodiments, after the object is in contact with the critical fluid to remove the contaminants, the supercritical fluid is collected and collected into the 'in which the pressure and / or temperature is changed to remove the contaminants from the fluid Out. For example, in FIG. 1, the object 14 held in the chamber 13 is immersed in a supercritical fluid flow. The supercritical fluid removes contaminants from the object 14 and flows through a valve 15 into a collection container 16. When the fluid passes through the valve 15, the pressure of the fluid decreases, and the supercritical fluid is converted into a gas in the collecting container worker 6. Soluble in fluid

Page 12 496789 V. Description of the invention (9) To condense and recover the fluid for use in the cleaning method. For example, Fig. 1 shows a collection container 17 into which a gaseous HFC or HCFC fluid is poured and condensed into a liquid HFC or HCFC fluid. The liquid HFC or HCFC fluid can be recycled to the container 11 for reuse. Examples In order that the present invention may be more easily understood, the present invention is illustrated but not limited in scope. This example illustrates the effectiveness of various HFCs and HCFCs in cleansing applications. Four kinds of HFC / HCFC fluids were prepared according to the present invention 1 and tested for their effectiveness in cleaning circuit boards. The four fluids, including r-2y'R-32'R-134a and R-125 'with 0.5% by weight of methanol, were tested under various temperature and pressure environments. The results of such tests are summarized in Table 1. The tritium fluid of the present invention meets or exceeds the cleaning power of carbon dioxide and is used as an industry standard cleaning fluid. For comparison, the cleaning effectiveness of carbon dioxide, R-125 (pure) and R-U3a was tested, and these results are shown in Table 1. α H F C / H C F C and carbon dioxide fluid are measured by the following experimental method-Go. Example method. Cut a 2-inch x 2.5-inch sampling board from the circuit board. / 'Clean each sample plate and apply fully activated soldering flux on both sides ^^ ⑶ 1 585 RA flux]. The average coating per sample plate was 20 mg per square inch. The two sampling plates were then hung on a rack. Place the rack in a high-pressure vessel washed with water and isopropanol to remove any ionic contaminants. Cry the speech and seal it and empty it. Thereafter, the vacuum cleaner and moist ice cubes were used to fill the container with the cleaning fluid. As soon as the fluid was filled, ^ containers were placed in the experimental temperature equilibrium bath. Or cry high pressure

496789 V. Description of the invention αο) Wrapped by a heat shield controlled by a thermoset at a desired temperature, and kept exposed to heat-up, for a time sufficient to achieve the required temperature. Thereafter, the exposure time was calculated. After the time required for exposure, allow fluid to escape from the container and condense in a collection container for disposal. Thereafter, the sampling plate was removed from the container and the cleanliness was measured with an alpha metal omega ruler 600. The plate was cleaned with isopropanol and the conductivity of the isopropanol washes was measured using a conductivity meter to measure the amount of assisting the indwelling plate. The cleanliness data presented in Table 1 suggest a reduction in the amount of flux retained on the board

Cleanliness effectiveness of various fluids. Number of fluid pressure PSIA] Temperature, UC time minutes)% Jie C1 CO: 1300 40 45 < 10 C2 R-125 (near) S75 95 45 < 10 C3 R-I43a & 25 95 45 < 10 Ε1 R-22 775 100 45 100 Ε2 R-22 151 25 45] 〇0 Ε3 R-22 151 25 5 78 Ε4 R-32 J200 100 45 90 Έ5 R-32 875 so 45 80 Ε6 R-32 707 、 70 45 65 Ε7 R-32 245 25 45 10 Ε8 R-134a 700 110 45 60 £ 9 R-125 / 0.5 wt% MeOH 875 95 45 60

As shown in Table 1, when such H F C ’s and H C F C’ s flow systems

Page 14/07 / 07 V. Description of the invention Gl) Ionic soldering flux during the application of degree and pressure It is found that when the ionic substances are removed at a slightly lower body to the extent that it is considered to be a poor cleaning, the tendency is improved, but it is particularly about the removal Therefore, it is described that an example of the present invention will be easy to make a variety of improvements, but it is not limited to what is specified in the sentence = a type of HFC and HCFC. From the test sample plate, the performance surpasses the dioxide disk dramatically. . To a lesser extent. Such as these same stream compounds. Although, hfc ’s are therefore known to be…, the degree of dissolution in the critical region = HFC ’, and the degree of removal of pollutants is unexpected. This is because supercritical CO2 did not exhibit this phenomenon. , The specific embodiment of the month of talent, familiar with this art, A ° Zhou Zhenghe and improvement. For all such alternatives, adjust the parts described in Tea ^ 2, although not indicated here, within the range of It and Range. Therefore, the above description is only based on the application of Ming Ming, and the party scope is the same as the scope and meaning of the following patent applications.

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Claims (1)

496789 VI. Scope of patent application1. A method for cleaning manufactured articles containing contaminants on the surface, including the steps of (a) providing a hydrohalocarbon compound as a supercritical fluid; (b) contaminating the contaminated surface of the manufactured article with the supercritical fluid; Critical fluid contact; and (c) almost completely removing the supercritical fluid from the contaminated surface of the article of manufacture. 2. The method according to application_patent scope item 1, wherein the supercritical fluid ^ includes HFC. : > 3. The method according to item 2 of the scope of patent application, wherein the HFC is selected from δ R-32, R-125, R-134, R-134a, R-23, R-143, R-143a, R-245fa, R-245ea, R-245ca, R-245eb and a mixture of two or more of them. 4. The method according to item 2 of the scope of patent application, wherein the supercritical fluid further comprises an oxidized compound selected from the group consisting of aldehydes, ketones, esters, ethers and alcohols. -5. The method according to item 4 of the scope of patent application, wherein the oxidizing compound is an alcohol selected from the group consisting of methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol and tertiary butanol. . 6. The method according to item 2 of the patent application range, wherein the supercritical fluid further comprises about 0.1% by weight to about 0.9% by weight of methanol. 7. The method according to item 1 of the patent application scope, wherein the supercritical fluid includes HCFC. 8. The method according to item 7 of the scope of patent application, wherein the HCFC is selected I Page 17 496789 VI. The scope of application for patents consists of R 2 2, R-丨 2 4 and mixtures thereof. 9. According to the group of the scope of application for patents, the group includes the selection of free acids, such as the "Summarization, Omission, and Methods", where Supercritical fluids. ^, The oxidative combination of the group 10. According to the scope of the patent application, where the supercritical fluid is in which the supercritical fluid is in which the supercritical fluid is in which the providing step = the choice of free methanol, ethanol, ^ = method, in which the compound is oxidized Alcohols and tertiary butanols; alcohol group: isopropyl alcohol 'n-butanol' isobutyl. According to the claim, the scope of the patent is to go in two ways. 1 At least-Lion C and at least-HCFC. 2 · According to the scope of patent application, it is the supercritical state. Method 1 3 · The method according to item 丨 of the scope of patent application is liquid evil. 1 4 · Provide an HFC or HCFC W according to the first one of the scope of the patent application item 1 _ about 10 C to about 200 c. 15 · The method according to the scope of the patent application item 14, wherein the providing step (a) includes Provide an hfc or HCFC at a temperature of about 15 ° C to about 1 30 ° C. 16 · The method according to claim 14 of the patent scope of the application, wherein the providing step (3) includes providing a {^ 匸 or HCFC at a pressure of about 25 mouths 3 丨 3 to about 10,000,03,8. . 17. The method according to item 15 of the scope of patent application, wherein the providing step (a) includes providing an HFC or HCFC at a pressure of about 100 psia to about 3,500 psia. 1 8 · The method according to item 1 of the scope of patent application, wherein the contacting step 2 Page 18 496789 VI. Scope of patent application (b) Including covering at least the contaminated part of the object with the supercritical fluid. 19. The method according to item 18 of the scope of patent application, wherein the contacting step (b) further comprises dissolving at least part of the pollutants on the contaminated part of the object in the supercritical fluid. 20. The method according to item 1 of the scope of patent application, wherein the contacting step (b) comprises immersing at least a contaminated portion of the object in the supercritical fluid flow. 2 1. The method according to item 1 of the patent application scope, wherein the removing step (c) comprises converting the supercritical fluid into a gaseous state. A 2 2. The method according to item 21 of the scope of patent application, wherein the step of converting the supercritical fluid to a gaseous state includes changing the pressure accepted by the supercritical fluid. 2 3. The method according to item 22 of the scope of patent application, wherein the step of converting the supercritical fluid to a gaseous state includes changing the temperature of the supercritical fluid. 2 4. A method according to item 1 of the scope of patent application, wherein the article of manufacture includes a printed circuit board. 25. The method according to item 1 of the scope of the patent application, wherein the article of manufacture includes a Shi Xi wafer. Page 19