JPWO2005084831A1 - Method for removing alkali-soluble photosensitive resin - Google Patents

Abstract

Provided is an alkali-soluble photosensitive resin peeling method which can be carried out easily and efficiently by reducing the amount of chemicals used as much as possible. Dry ice particles are sprayed in the dry ice spraying device (40) onto the body (80) to which the alkali-soluble photosensitive resin is adhered. The peeled pieces are collected by a filter in an electrolytic acid water tank (60) and a recovery tank (70). Subsequently, the to-be-cleaned body (80) wash | cleans a peeling residue in an electrolytic acid water spray apparatus (50), and neutralizes and wash | cleans electrolytic acid water in a water washing tank (90). In addition, since the electrolytic acid water used for peeling and recovery of the alkali-soluble photosensitive resin can be reused, the amount of waste liquid discharged can be greatly reduced.

Description

  The present invention relates to a peeling method in which, for example, in a manufacturing process of a printed wiring board, it is possible to easily remove a cured alkali-soluble photosensitive resin and recover a peeled piece.

  Alkali-soluble photosensitive resin is an etching mask used for decorative processing of iron-containing products mainly containing stainless steel and copper-containing products such as phosphor bronze, and circuit formation of semiconductors and printed wiring boards using copper foil. It is used as a material and mask material for plating. However, in the process of removing the alkali-soluble photosensitive resin from the printed wiring board after etching and plating, the process is based on a chemical reaction with a large amount of chemicals from the removal of the photosensitive resin to the waste liquid treatment. Is incorporated.

  On the other hand, recently, pollution problems of the global environment have emerged. For air pollution, the use of trichloroethane and trichlorethylene as the root cause of the destruction of the ozone layer is prohibited. For river pollution, environmental conditions such as factory effluent standards and industrial waste regulations. Is protecting.

  However, there is a limit to diluting with a large amount of water and clearing pollution standards such as COD and BOD, and the regulation of the total amount of wastewater from factories has been introduced. Therefore, for example, in the manufacturing process of the printed wiring board, in order to use a large amount of chemicals in the peeling process of the alkali-soluble photosensitive resin, as it is, the production amount is forced to be limited, The processing method using only the chemicals currently in use is being reviewed.

  As a method of cleaning the deposits that do not generate waste liquid, a dry method that does not use chemicals can be considered. As a dry method, for example, a cleaning technique using dry ice is known, and inventions according to applications in various fields have been made.

  For example, in the following Patent Document 1, in the step of peeling off the resin deposit adhered in the low temperature pulverization apparatus of the resin raw material, the dry ice particles are collided with the surface to be cleaned, and the resin deposit on the surface to be cleaned is peeled off. Is disclosed.

  In addition, in Patent Document 2 below, in order to enhance the cleaning ability by dry ice particles, the deposits adhered to the surface to be cleaned are sufficiently impregnated with a cleaning agent such as a surfactant, alkali builder, soap, It has been disclosed to improve the effect of removing deposits by dry ice.

Further, in Patent Document 3 below, in the step of peeling the photoresist on the semiconductor substrate, the pre-treatment by water treatment and freezing treatment is performed on the object to be cleaned, and then dry ice particles are sprayed on the semiconductor substrate. It is disclosed to remove deposits.
Japanese Examined Patent Publication No. 4-51233 JP-A-6-182306 JP 2000-58494 A

  As described above, for example, in the manufacturing process of a printed wiring board, a large amount of chemicals are used to peel the alkali-soluble photosensitive resin remaining after etching from the printed wiring board.

  However, in the conventional peeling method using only chemicals, a large amount of waste liquid is discharged at the same time, so the load on the environment is large. Furthermore, since the peeling piece is dissolved in a chemical and is in the form of a stick, a great effort and burden are imposed on the recovery and disposal of these pieces.

  Therefore, in order to reduce the discharge amount of waste liquid and make it possible to easily collect and process the peeled pieces, instead of using the current method of using chemicals, dry ice that can be washed in a dry process is used. Pay attention.

  This method of peeling off deposits using dry ice is used in various fields. However, as in Patent Document 1 described above, by simply spraying dry ice particles onto the object to be cleaned, the photosensitive resin cannot be completely removed, and a residue like residue remains. Furthermore, although dew condensation occurs by spraying dry ice particles on the object to be cleaned, there is also a problem that if the object to be cleaned is a metal product, the object to be cleaned is damaged due to the occurrence of rust. there were. Moreover, it is possible to improve the peeling effect by dry ice particles by pretreating the deposit as in Patent Documents 2 and 3, but a pretreatment step is necessary, and time and cost are required. There was a problem.

  Therefore, an object of the present invention is to provide an alkali-soluble photosensitive resin peeling method that can be carried out easily and efficiently by reducing the amount of chemicals used as much as possible.

  In achieving the above object, according to the first aspect of the present invention, the alkali-soluble photosensitive resin is peeled off by spraying dry ice particles onto the object to be cleaned to which the alkali-soluble photosensitive resin is adhered, It is characterized by performing washing with water.

  According to the present invention, the alkali-soluble photosensitive resin is cooled by spraying dry ice particles onto the object to be cleaned, to which the alkali-soluble photosensitive resin is adhered, but fine cracks are caused by a sudden temperature change. Will occur. Since the dry ice particles are ejected at a high speed, the photosensitive resin adhering to the object to be cleaned is effectively peeled and removed by the impact force and the expansion energy generated when the dry ice sublimates. be able to. Further, since dry ice is a sublimable substance, when it reaches the surface layer of the object, it vaporizes and becomes carbon dioxide, so that the alkali-soluble photosensitive resin can be peeled without damaging the object to be cleaned.

  However, the alkali-soluble photosensitive resin cannot be completely peeled off only by spraying dry ice particles. Fine alkali-soluble photosensitive resin peeling residue, traces like pigments, rust caused by condensation, and traces of water droplets remain on the surface of the object to be cleaned, but this alkali-soluble photosensitive resin is acidic. Since it has a property of solidifying in the region, the alkali-soluble photosensitive resin can be peeled off by washing with electrolytic acid water. Further, since traces such as pigments, rust caused by condensation, and traces of water droplets can be cleaned at the same time, a clean processed surface can be obtained. Moreover, it is preferable that the electrolytic acid water used here is what was heated beforehand at about 20-70 degreeC, and was excellent in the removal of a peeling residue, and removal of the water film etc. which are formed from dew condensation. Can be demonstrated.

  In addition, the second method for removing the alkali-soluble photosensitive resin of the present invention is a method in which dry ice particles are sprayed on the object to be cleaned to which the alkali-soluble photosensitive resin is adhered, and then washed with electrolytic alkaline water or alkaline chemicals. It is characterized by performing.

  Depending on the processing speed, the alkali-soluble photosensitive resin may not be completely removed from the surface of the object to be cleaned only by spraying dry ice particles. On the other hand, since it is an alkali-soluble photosensitive resin, it can be dissolved and removed using electrolytic alkaline water, which is strongly alkaline water, or an alkaline chemical solution.

  Therefore, depending on the processing speed, after spraying dry ice particles, by further washing with electrolytic alkaline water or alkaline chemical solution, the alkali-soluble photosensitive resin can be completely peeled from the surface of the object to be cleaned, A clean processed surface can be obtained, and most of the alkali-soluble photosensitive resin can be peeled off from the surface of the object to be cleaned by spraying dry ice particles, so even if alkaline chemicals (chemicals) are used However, the amount of use can be greatly reduced.

  In the second aspect of the invention, it is preferable to wash the object to be cleaned with electrolytic alkaline water or an alkaline chemical solution, and then further wash with electrolytic acidic water.

  As described above, since the alkali-soluble photosensitive resin has a property of solidifying in the acidic region, after dissolving the peeling residue using electrolytic alkaline water or an alkaline chemical solution, further spraying electrolytic acidic water, By making the object to be cleaned an acidic region, it is possible to coagulate and condense the stripped pieces dissolved in the electrolytic alkaline water or alkaline chemical solution, and to remove the stripped residue more efficiently, Processing becomes easy. Further, since traces such as pigments, rust caused by condensation, and traces of water droplets can be removed at the same time, a clean processed surface can be obtained.

  Further, in the present invention, when spraying dry ice particles onto the object to be cleaned, the periphery thereof is covered with a recovery cover, and the separated and scattered alkali-soluble photosensitive resin is sucked from the recovery cover. It is preferable that it is configured so that it can be recovered.

  Since the alkali-soluble photosensitive resin is peeled from the object to be cleaned by colliding with high-speed dry ice particles, the peeled pieces are considerably scattered around. Therefore, when spraying dry ice particles to the object to be cleaned, it is configured to wrap the surrounding area with a recovery cover and suck it from the recovery cover to recover the peeled pieces, thereby efficiently peeling without scattering to the surroundings. Pieces can be collected.

  In the present invention, it is preferable that at least the surface of the recovery cover is formed of a fluororesin or a silicon resin. Since the fluororesin or silicon resin has low reactivity with other substances, it is possible to prevent the object to be cleaned that has peeled off the wall surface from being reattached, so that the recovery cover can be prevented from being contaminated.

  Further, in the present invention, the suctioned alkali-soluble photosensitive resin, the suctioned photosensitive resin is recovered using a centrifugal force generated by a cyclone flow, a recovery method using an air filter, and electrolytic acid water It is preferable to recover by at least one method selected from a recovery method of introducing into a water tank in which water is stored and solidifying and precipitating. Since the peeled alkali-soluble photosensitive resin does not contain moisture, it can be easily recovered by a centrifugal force by a cyclone flow or an air filter. Further, since the alkali-soluble photosensitive resin is solidified in the acidic region as described above, the peeled piece can be easily recovered by introducing it into a water tank in which electrolytic acid water is stored and solidifying and precipitating. The electrolytic acid water used for peeling off the alkali-soluble photosensitive resin and the electrolytic acid water used for recovery do not dissolve the peeled pieces. It can be used, and the amount of waste liquid discharged can be greatly reduced.

  In the dry ice particle injection step of the present invention, it is preferable to use dry ice particles having a diameter of 5 to 50 μm, an injection pressure of 0.01 to 5.0 MPa, and an injection time of 5 to 120 seconds. According to this, the alkali-soluble photosensitive resin can be effectively peeled without damaging the object to be cleaned.

  Moreover, the electrolytic acid water used in the present invention preferably has a pH of 4.0 or less and a residual chlorine concentration of 15 ppm or less.

  By setting the pH of the electrolytic acid water to 4.0 or less, the alkali-soluble photosensitive resin can be effectively coagulated and condensed, so that peeling and recovery can be easily performed. Moreover, generation | occurrence | production of a basic carbonate and corrosion of a to-be-cleaned body can be suppressed by a residual chlorine density | concentration being 15 ppm or less.

  The electrolytic acid water is preferably obtained from the anode side by electrolyzing water using an electrolytic cell having an ion-permeable membrane or a neutral membrane between the cathode and the anode.

  When a chloride compound such as sodium chloride or potassium chloride is used as the electrolyte, chlorine gas is generated by electrolysis at a low voltage, and therefore electrolysis is performed at a high voltage, for example, an applied voltage of 20 V to 60 V. It is preferable to do this. In addition, when a sulfide-based compound such as sodium sulfate, ammonium sulfate, or potassium sulfate is used as the electrolyte, there is no generation of chlorine gas due to electrolysis, so electrolysis at a low voltage of 5 V to 50 V is possible. It can implement suitably.

  Moreover, the electrolytic alkaline water used in the present invention preferably has a pH of 10.0 or more and a redox potential of −50 mV or less.

  And this electrolytic alkaline water is obtained from the cathode side by electrolyzing water at a voltage of 5 to 60 V using an electrolytic cell having an ion-permeable membrane or a neutral membrane between the cathode and the anode. Is preferred.

  Furthermore, in the present invention, according to the property of the object to be cleaned, while transporting the object to be cleaned, either dry ice particles are ejected from both the upper and lower surfaces of the object to be cleaned, or one of the upper and lower surfaces of the object to be cleaned Is supported by a belt-like transport mechanism, and dry ice particles are preferably ejected from the other surface to be separated.

  According to the present invention, in the step of removing the alkali-soluble photosensitive resin, after dry ice is sprayed onto the object to be cleaned to which the photosensitive resin is adhered, the peeled piece is collected, and then washed with electrolytic acid water. As a result, it is possible to easily collect the peeled pieces as compared with the conventional peeling method using chemicals.

  Furthermore, since the electrolytic acid water used in the present invention can be reused, the waste liquid is hardly discharged and the factory waste water can be reduced. In addition, since almost all the peeled pieces in the waste liquid can be collected, the waste liquid treatment is also easy.

It is the schematic which shows an example of the apparatus for manufacturing the electrolytic acid water used for this invention, and electrolytic alkaline water. It is the schematic which shows an example of the system for peeling the alkali soluble photosensitive resin used for this invention. It is the schematic which shows an example of the dry ice injection apparatus 40 used for this invention. It is the schematic which shows another example of the dry ice injection apparatus 40 used for this invention. It is the schematic which shows an example of the collection tank 70 used for this invention. It is the schematic which shows another example of the collection tank 70 used for this invention. It is the schematic which shows another example of the system for peeling the alkali-soluble type photosensitive resin used for this invention.

Explanation of symbols

12 Electrolyzer 13. Cathode 14. Anode 17. Diaphragm 18. Cathode chamber 19. Anode chamber 23. Electrolytic alkaline water outlet pipe 26. Electrolytic acid water outlet tube 40. Dry ice spraying device 41. Ring conveyor 42. Belt conveyor 43. Dry ice particle injection nozzle 44. Collection cover 45. Suction tube 50. Electrolytic acid water spray device 51. Sprayer 52, 61, 72, 73. Filter tank 55. Electrolytic alkaline water spray device 60. Electrolytic acid bath 70. Collection tank 71. Suction machine 74. Air filter 75. Nebulizer 80. Object to be cleaned 90. Washing tank P1-P4. pump

  The electrolytic acid water used in the present invention is basically strongly acidic ionic water obtained by electrolyzing water in an electrolytic cell. The electrolytic alkaline water is basically electrolyzed in an electrolytic cell. It is strongly alkaline ionic water obtained by doing.

  FIG. 1 shows an example of an apparatus using an electrolytic cell having an ion-permeable membrane between an anode and a cathode as an apparatus for producing preferable electrolyzed water used in the present invention.

  This apparatus is mainly composed of a raw water introduction pipe 1, a connection pipe 6, a filter tank 5, an electrolytic tank 12, an electrolytic alkaline water outlet pipe 23, and an electrolytic acid water outlet pipe 26 provided in the middle thereof. Here, the raw water introduction pipe 1 is connected to a filter tank via a pressure reducing valve 2, a pressure switch 3, and an electromagnetic valve 4, and further connected to an electrolytic tank 12 through a connection pipe 6.

  The electrolytic cell 12 has a cylindrical stainless steel electrode or a cathode 13 made of a titanium + platinum electrode and an anode 14 made of a cylindrical titanium + platinum electrode having a diameter smaller than that of the cathode 13 arranged concentrically. The upper and lower end surfaces are sealed with annular lids 15 and 16. A cylindrical diaphragm 17 is also installed between the cathode 13 and the anode 14 so that both ends thereof are supported by the lids 15 and 16, and the inside of the electrolytic cell 12 is provided with an outer cathode chamber 18, The inner anode chamber 19 is partitioned at a volume ratio of 45:55. In addition, not only the electrolytic cell partitioned by the cylindrical partition as shown in FIG. 1, but a flat plate electrolytic cell partitioned by a flat diaphragm into an anode chamber and a cathode chamber can be used. The volume ratio of the cathode chamber is preferably 5: 5.

  The diaphragm 17 transmits cations from the anode chamber 19 side to the cathode chamber 18 side, and transmits anions from the cathode chamber 18 side to the anode chamber 19 side.

  The connecting tube 6 has its tip branched into 6a and 6b. One tube 6a is connected to the introduction path 20 into the cathode chamber 18 provided in the lid 16 at the bottom of the electrolytic cell 12, and the other tube 6b. Are connected to an introduction path 21 into the anode chamber 19 provided in the lid body 16, and both have a structure in which raw water having the same diameter and the same pressure is introduced.

  In addition, a lead-out path 22 for taking out electrolytic alkaline water from the cathode chamber 18 is formed in the lid 15 at the top of the electrolytic cell 12, and an electrolytic alkaline water lead-out pipe 23 is connected to this, and a flow control valve 28. Electrolytic alkaline water is supplied through the flow rate adjusting valve (before the introduction of the electrolytic cell). Furthermore, a lead-out path 25 for taking out the electrolytic acid water from the anode chamber 19 is formed in the upper lid body 15, and an electrolytic acid water lead-out pipe 26 is connected to this, and a flow rate control valve 29 (the flow rate adjustment valve is electrolyzed). The electrolytic acid water is supplied via a tank before the introduction.

  The electrolytic cell 12 is provided with a power source 30 that supplies power to the anode 14 and the cathode 13 and a control device 31 that controls power from the power source 30. Although not shown, a resin jig for holding the diaphragm along the axial direction of the anode 14 is disposed in the anode chamber 19.

  Therefore, when the raw water is introduced from the raw water introduction pipe 1 into the filter tank 5 through the pressure reducing valve 2, the pressure switch 3, and the electromagnetic valve 4, the raw water has a particle size of 10 μm or more so that the diaphragm 17 is not clogged. Is trapped and flows out from the connecting pipe 6.

  The raw water flowing out from the connecting pipe 6 is branched into the branch pipes 6a and 6b and flows into the cathode chamber 18 and the anode chamber 19 of the electrolytic cell 12 with the same pressure and the same amount, respectively. The raw water that has flowed into the anode chamber 19 flows in the anode chamber 19. In the electrolytic cell 12, a voltage is applied between the anode 14 and the cathode 13, and electrolysis of raw water is performed. At this time, the power is adjusted by the control device 31 so that the voltage is 50 to 60 V and the current is 15 to 25 A, and the electrolytic acid water is discharged from the anode chamber 19 at a flow rate of 1.5 to 2.0 liters / minute, The flow rate is adjusted so that electrolytic alkaline water is discharged from the cathode chamber 18 at a flow rate of 1.5 to 2.0 liters / minute.

  By such a method, the acidic acidic water having a pH of 4.0 or lower and the residual chlorine concentration of 15 ppm or lower, the pH of 10.0 or higher, and the redox potential is −50 mV or lower. Electrolytic alkaline water can be produced.

  When producing electrolytic acid water and electrolytic alkaline water, chloride compounds such as sodium chloride and potassium chloride; sulfide compounds such as sodium sulfate, ammonium sulfate and potassium sulfate are used as electrolytes, both of which are compounds. Can also be suitably used as an electrolyte.

  However, when a chloride compound is used as the electrolyte, the electrolysis at a low voltage requires the electrolysis at a high voltage because chlorine gas is generated at the same time. Therefore, when a chloride compound is used as the electrolyte, the applied voltage for electrolysis is preferably 20 to 60 V, more preferably 50 to 60 V.

  On the other hand, when a sulfide-based compound is used as the electrolyte, since no toxic gas such as chlorine gas is generated, it can be suitably carried out even at low voltage electrolysis. As for it, it is preferable that it is 5-50V, and it is more preferable that it is 10-20V.

  In addition, the alkaline chemical solution that can be used in the present invention is a strongly alkaline chemical that has been conventionally used for stripping an alkali-soluble photosensitive resin, such as a sodium hydroxide solution or a potassium carbonate solution. There is no limitation.

  In the present invention, removal of the peeling residue with electrolytic acid water, electrolytic alkaline water, or alkaline chemical solution is generally preferably performed by showering, but may be ultrasonic cleaning by immersion.

  FIG. 2 shows an example showing an outline of a preferable alkali-soluble photosensitive resin peeling apparatus for carrying out the present invention.

  That is, this preferable system as a whole is basically an electrolytic acid for recovering the peeled pieces peeled off from the dry ice spray device 40, the electrolytic acid water spray device 50, and the dry ice spray device 40 covered by the recovery cover. The water tank 60 and the recovery tank 70 for recovering the peeled pieces separated in the dry ice spray device 40 are mainly configured.

  An object to be cleaned 80 (hereinafter simply referred to as an object to be cleaned) is installed on the ring conveyor 41 and is transported to the dry ice jetting device 40, where dry ice particles are jetted.

  Examples of the object to be cleaned include a printed wiring board, a SUS plate, a phosphor bronze plate, and a hastelloy plate (nickel alloy) after plating or etching.

  The dry ice particles used in the dry ice jet device 40 preferably have a particle size of 5 to 50 μm, and more preferably 5 to 30 μm. If the particle size of the dry ice particles is 50 μm or more, the object to be cleaned is damaged, and if it is 5 μm or less, the cleaning effect is poor and the alkali-soluble photosensitive resin cannot be peeled off, which is not preferable. .

  Moreover, it is preferable that an injection pressure is 0.01-5.0 MPa, More preferably, it is 0.01-0.7 MPa, More preferably, it is 0.015-0.025. If the spray pressure is 5.0 MPa or less, the alkali-soluble photosensitive resin can be peeled without damaging the object to be cleaned, and in particular, if it is 0.7 MPa or less, the metal decorated on the substrate surface Even if the film is a thin film, the metal film does not extend, so that the dimensional accuracy is not impaired. In addition, if the injection pressure is 0.01 MPa or more, most of the alkali-soluble photosensitive resin can be peeled and removed from the surface of the object to be cleaned, so the amount of electrolytic acid water, electrolytic alkaline water, alkaline chemicals, etc. can be reduced. The removal work of the peeling residue in the subsequent process becomes easy.

  The spraying time is preferably 5 to 120 seconds, and more preferably 30 to 50 seconds, although it depends on the size of the object to be cleaned. When the spraying time is 120 seconds or more, condensation is likely to occur on the object to be cleaned, like frost, and the amount of traces of water drops increases, and when it is 5 seconds or less, the alkali-soluble photosensitive property The resin may not be sufficiently peeled off.

  The dry ice spraying device 40 is the device shown in FIG. 3 or 4 depending on the properties of the object to be cleaned. When the object to be cleaned is a thin plate and easily damaged, in the apparatus shown in FIG. 3, one of the upper and lower surfaces of the object to be cleaned is supported by the belt conveyor 42, and the remaining surface is sprayed with dry ice particles. The nozzle 43 is installed and has a structure for ejecting dry ice particles. When the object to be cleaned is not easily damaged, dry ice particle injection nozzles 43 are provided on the upper and lower surfaces of the object to be cleaned as shown in FIG. It has the structure which injects.

  As the shape of the dry ice particle injection nozzle 43, a flat type nozzle capable of accommodating a wide area, a cone type nozzle capable of ensuring a stronger injection pressure, and a cylindrical nozzle capable of ensuring a dry ice injection speed can be used. Preferably, it is a cylindrical nozzle that can ensure the spray speed of dry ice.

  The outer periphery of the dry ice spray device 40 is covered with a recovery cover 44, which prevents the peeled-off alkali-soluble photosensitive resin from scattering to the periphery, and from suction pipes 45 installed above and below the recovery cover 44. The peeled alkali-soluble photosensitive resin is sucked from a suction machine 71 installed outside the dry ice spraying device 40, and the peeled alkali-soluble photosensitive resin is recovered in the recovery tank 70 and dry ice is collected. Carbon dioxide generated during particle injection is exhausted. The exhausted carbon dioxide gas is treated with a scrubber or the like circulating lime water.

  Moreover, it is preferable that at least the surface of the recovery cover 44 is formed of a fluororesin or a silicon resin. Since the fluororesin or silicon resin has low reactivity with other substances, it is possible to prevent the alkali-soluble photosensitive resin peeled off from the wall surface from reattaching, and to suppress contamination on the recovery cover wall surface.

  The collection tank 70 may be a tank that collects only with an air filter, such as a vacuum cleaner for home appliances. However, since it is assumed that the collection tank 70 is clogged immediately, the collection tank 70 uses a centrifugal force generated by a cyclone flow like a cyclone type vacuum cleaner. It is preferable to use the mechanism, the collection tank shown in FIG. 5, or the collection tank shown in FIG. 6, and both of the collection tanks in FIGS. 5 and 6 can be suitably used.

  First, a method for recovering the alkali-soluble photosensitive resin using the recovery tank in FIG. 5 will be described. The recovery tank of FIG. 5 is filled with electrolytic acid water, and the sucked peeling pieces can be introduced into the electrolytic acid water to be solidified and precipitated. The piping from the bottom of the recovery tank is connected to the filter tank 72 via the pump P1, and the separated alkali-soluble photosensitive resin is recovered in the filter tank 72. The piping from the filter tank 72 is connected to the upper part of the recovery tank 70, and the electrolytic acid water here can be reused.

  In the collection tank of FIG. 6, electrolytic acid water is sprayed from the sprayer 75, the peeled alkali-soluble photosensitive resin is aggregated, and the alkali-soluble peeled by the air filter 74 installed in front of the suction device 71. The type photosensitive resin is collected. In order to spray electrolytic acid water, electrolytic acid water is stored in the lower part of the recovery tank, but a pipe for extracting the electrolytic acid water stored from the bottom of the recovery tank is connected to the filter tank 73 via the pump P2. In the filter tank 73, the alkali-soluble photosensitive resin dropped into the recovery tank by spraying electrolytic acid water is recovered, and the pipe from the filter tank 73 is connected to the sprayer 75. The electrolytic acid water here can be reused.

  In addition, the electrolytic acid water used in the collection tank in FIGS. 5 and 6 has a pH of preferably 4.0 or less, and preferably 3.0 or less in order to efficiently recover the peeled pieces. Is more preferable.

  Moreover, the dry ice injection device 40 has a structure in which the outer peripheral portion is covered with a recovery cover. Since a part of the peeling piece may scatter from the entrance / exit part of the dry ice spraying device, in order to collect the peeling piece scattered to the outside, electrolysis with electrolytic acid water stored in the lower part of the dry ice jetting device 40 The peeled piece is collected using the acidic water tank 60 (see FIG. 1). A pipe from the bottom of the electrolytic acid water tank 60 is connected to the filter tank 61 via the pump P3, and the separated and scattered alkali-soluble photosensitive resin is collected in the filter tank 61. The piping from the filter tank 61 is connected to the upper part of the electrolytic acidic water tank 60, and the electrolytic acidic water here can be reused.

  The electrolytic acidic water used in the recovery tank 70 and the electrolytic acidic water tank 60 has a pH of preferably 4.0 or less and more preferably 3.0 or less in order to efficiently recover the peeled pieces.

  The dry ice particles are ejected by the dry ice spraying device 40 and the object to be cleaned from which the alkali-soluble photosensitive resin is peeled is then conveyed to the electrolytic acid water spraying device 50.

  The electrolytic acid water spray device 50 has a structure in which electrolytic acid water is sprayed from the sprayer 51 onto the object to be cleaned. The electrolytic acid water stored in the electrolytic acid water device is connected to the filter tank 52 through a pump P4 through a pipe for extracting the stored electrolytic acid water from the bottom of the device. The peeled alkali-soluble photosensitive resin is collected in the filter tank 52, the pipe from the filter tank 52 is connected to the sprayer 51, and the electrolytic acid water can be reused. ing.

  The electrolytic acid water used here has a pH of preferably 4.0 or less, and more preferably 3.0 or less, in order to efficiently peel the peeling residue. Moreover, it is preferable that the temperature is heated to 20 to 70 ° C., but the one heated to 35 to 45 ° C. can exhibit an excellent effect in removing the peeling residue, It is more preferable because it is less likely to decrease due to evaporation.

  The spraying time is preferably 5 to 120 seconds, and more preferably 30 to 80 seconds. If it is 120 seconds or more, the cleaning efficiency is deteriorated, and if it is 5 seconds or less, the peeling residue can hardly be removed.

  Next, the object to be cleaned sprayed with the electrolytic acid water by the electrolytic acid water spray device 50 is moved to the water washing tank 90, and neutralization cleaning of the electrolytic acid water adhering to the surface of the object to be cleaned is performed. Then, it moves to the next process and is carried to a drying process (not shown).

  In this way, peeling of the alkali-soluble photosensitive resin is completed.

  Moreover, another example which shows the outline | summary of the preferable peeling apparatus of the alkali soluble photosensitive resin preferable for implementing this invention is shown by FIG. In the following description of the alkali-soluble photosensitive resin peeling device, the same parts as those of the peeling device are denoted by the same reference numerals, and the description thereof is omitted.

  This peeling device basically recovers the peeled pieces peeled from the dry ice spray device 40, the electrolytic alkaline water spray device 55, the electrolytic acid water spray device 50, and the dry ice spray device 40 covered with the recovery cover. 1 is mainly composed of a recovery tank 70 for recovering the peeled pieces separated in the electrolytic acid water tank 60 and the dry ice spraying apparatus 40, and is different from the peeling apparatus shown in FIG. An electrolytic alkaline water spray device 55 is newly installed after the device 40. Here, spraying is performed on the object to be cleaned in electrolytic alkaline water, and the alkali-soluble photosensitive resin that cannot be completely peeled off by spraying and peeling off the dry ice particles is dissolved.

  In order to dissolve the peeling residue efficiently, the pH of the electrolytic alkaline water is preferably 10.0 or more, and more preferably 11.0 or more. Moreover, it is preferable that electrolytic alkaline water is what was heated to 20-70 degreeC, and since it is excellent in the swelling power of peeling residue that it is what was heated to 50-60 degreeC, it is used more preferably. can do.

  The spraying time is preferably 10 to 60 seconds, and more preferably 30 to 50 seconds. If it is 60 seconds or more, the electrolytic alkaline water is oxidized by air to lower the pH, resulting in poor cleaning efficiency, and the consumption of electrolytic alkaline water is increased, increasing the cost burden, and in 10 seconds or less. If it exists, the effect is hardly seen, which is not preferable.

  Subsequently, it moves to the electrolytic acid water spraying apparatus 50, and removal of a peeling residue and surface cleaning are implemented. Thereafter, it is moved to a water washing tank 90, neutralized and washed with electrolytic acid water adhering to the surface of the object to be cleaned, transferred to the next step, and carried to a drying step (not shown). The peeling of the photosensitive resin is finished.

  In this way, when treating the peeling residue after spraying dry ice, cleaning with electrolytic alkaline water is performed in advance before washing with electrolytic acidic water, so that the treatment of the peeling residue with electrolytic acidic water is more efficient. Can be implemented.

  In addition, since the acidic acidic water used in the peeling step of the alkali-soluble photosensitive resin does not dissolve the peeled piece, it can be reused by removing the peeled piece by filter filtration or the like. Emissions can be greatly reduced.

  Furthermore, the waste water discharged from the rinsing tank 90 is weak acidic water and can be easily treated. Since the electrolytic acid water is basically water, for example, when generating the electrolytic acid water, it can be mixed with the electrolytic alkaline water generated at the same time at the cathode on the counter electrode side and neutralized. In the case of containing a large amount of water, it can be easily treated by performing an operation such as treatment of organic matter using activated sludge after neutralization.

  Moreover, although the alkali-soluble photosensitive resin is dissolved in the electrolytic alkaline water discharged from the electrolytic alkaline water spray device 55, the alkali-soluble photosensitive resin has a property of solidifying and condensing in an acidic region. Moreover, since electrolyzed water has the property of easily returning to neutrality, it is easy to lower the pH to an acidic region, and it is possible to recover the peeled pieces that are dissolved. Since electrolytic alkaline water is basically water like electrolytic acidic water, for example, when electrolytic alkaline water is produced, it is mixed with electrolytic acidic water simultaneously produced at the anode on the counter electrode side to adjust the pH of the aqueous solution to 4. By setting it to 0 or less, the peeled pieces that have been dissolved can be deposited, and the peeled pieces that have been easily dissolved by an operation such as filtration can be recovered. After the peeled piece is collected, it can be easily treated by adding neutral water such as electrolytic alkaline water again and neutralizing it.

  Further, in another aspect of the present invention, although not shown, the electrolytic alkaline water spray device 55 in FIG. 7 may be an alkaline chemical solution spray tank. In this embodiment, the alkaline chemical solution is sprayed onto the object to be cleaned in the alkaline chemical solution spray tank, and the dissolution of the alkali-soluble photosensitive resin that could not be completely peeled off by the spray peeling of the dry ice particles is achieved. It is carried out.

  In order to dissolve the peeling residue efficiently, the pH of the alkaline chemical solution is preferably 10.0 or more, and more preferably 11.0 or more. In addition, the alkaline chemical solution is preferably heated to 20 to 70 ° C, and more preferably used because it is heated to 50 to 60 ° C because of excellent swelling power of the peeling residue. can do.

  The spraying time is preferably 10 to 60 seconds, and more preferably 30 to 50 seconds. If it is longer than 60 seconds, the electrolytic alkaline water is oxidized by air to lower the pH, resulting in poor cleaning efficiency, and the consumption of the alkaline chemical solution is increased. The following is not preferable because almost no effect is seen.

  Subsequently, it is moved to an electrolytic acid water spray device, and removal of peeling residue and surface cleaning are performed. After that, it is transferred to a washing tank, neutralized and washed with electrolytic acid water adhering to the surface of the object to be cleaned, transferred to the next process, and transported to the drying process, thus alkali-soluble photosensitive resin The peeling of is finished.

  In the waste liquid discharged from the alkaline chemical solution spray tank, the alkali-soluble photosensitive resin is dissolved in the alkaline chemical solution, but the alkali-soluble photosensitive resin has the property of solidifying and condensing in the acidic region. For this reason, the peeled pieces that have been dissolved can be recovered by lowering the pH and lowering the acidic region to the acidic region. And after collection | recovery of a peeling piece, it can process easily by performing operations, such as adding alkaline water, such as an alkaline chemical solution, and neutralizing again. Further, since the amount of use can be significantly reduced as compared with the amount of conventional alkaline chemicals used, the load of waste water treatment can be drastically reduced.

  As described above, by using dry ice particles, electrolytic acid water, electrolytic alkaline water, and alkaline chemical solution for peeling and recovering the alkali-soluble photosensitive resin, it is easier to remove alkali than the conventional chemical-only peeling method. The soluble photosensitive resin can be peeled off, and the strips can be easily collected and the waste liquid treated.

  Hereinafter, the present invention will be described in more detail by way of examples. In addition, this invention is not limited to a following example.

(Production of printed wiring board)
A copper film having a thickness (total thickness from the base material) of 23 μm is formed on the surface of a printed wiring board (substrate material: glass epoxy resin) by panel plating, and a positive alkali-soluble photosensitive resin is further formed on the surface. A laminate of (made by Hitachi Chemical) was used. Then, the substrate was covered with a mask with a pattern cut and irradiated with ultraviolet rays. The uncured portion was removed by swelling with a 1% aqueous solution of sodium carbonate heated to 30 ° C. Etching with a ferric chloride solution was performed using the cured alkali-soluble photosensitive resin as a mask material.

(Production of electrolytic acid water and electrolytic alkaline water)
Using ion exchange water as the electrolytic raw water and sodium chloride as the electrolyte, using the apparatus shown in FIG. 1, voltage 60V, current 22A, flow rate of acidic ion water 1.8 liters / minute, flow rate 2 of alkaline ion water 2 Electrolysis was performed under the condition of 0.0 liter / min to produce electrolytic acidic water and electrolytic alkaline water. The electrolytic acid water and electrolytic alkaline water thus obtained were measured for redox potential (ORP), residual chlorine concentration (ppm) and pH, and the results are shown in Table 1.

ここで、ｐＨ及び酸化還元電位は、堀場製作所製のｐＨ／イオンメーターを用いて測定した。

Here, pH and oxidation-reduction potential were measured using a pH / ion meter manufactured by Horiba.

[Example 1]
The above-described printed wiring board adjusted to 600 mm square is installed and transported to the ring conveyor 41 shown in FIG. 2, and dry ice having an average particle size of about 30 μm is used with a dry ice spray device 40, using a cylindrical nozzle. It sprayed with respect to both surfaces of the printed wiring board for 15 second with the injection pressure of 0.7 MPa. And the peeled-off peeling piece was collect | recovered with the collection tank 70 of FIG.

  Next, electrolytic acidic water at 40 ° C. was sprayed for 20 seconds at a water pressure of 0.15 MPa.

  Subsequently, the clean water was washed with a water washing apparatus at a water pressure of 0.15 Mpa for 30 seconds and sufficiently dried, and then the state of the substrate was observed.

[Example 2]
The above-described printed wiring board adjusted to a 600 mm square is installed and transported on the ring conveyor 41 shown in FIG. 7, and dry ice having an average particle size of about 30 μm is used with a dry ice spray device 40 using a cylindrical nozzle. It sprayed with respect to both surfaces of the printed wiring board for 15 second with the injection pressure of 0.7 MPa. And the peeled-off peeling piece was collect | recovered with the collection tank 70 of FIG.

  Next, electrolytic alkaline water at 50 ° C. was sprayed at a water pressure of 0.15 Mpa for 30 seconds.

  Subsequently, after the electrolytic acid water at 40 ° C. was sprayed for 20 seconds at a water pressure of 0.15 MPa, the clean water was washed with a water washing device at a water pressure of 0.15 Mpa for 30 seconds and sufficiently dried. The state of the substrate was observed.

Example 3
A printed wiring board of Example 3 was manufactured in the same manner as in Example 1 except that a cylindrical nozzle shape was used, the spraying pressure of dry ice was 0.016 MPa, and the spraying time was 60 seconds. After drying, the state of the substrate was observed.

Example 4
A printed wiring board of Example 4 was manufactured in the same manner as in Example 2 except that a cylindrical nozzle shape was used, the spraying pressure of dry ice was 0.016 MPa, and the spraying time was 60 seconds. After drying, the state of the substrate was observed.

(Observation items)
The confirmation of the peeling residue, the presence or absence of a dent, the presence or absence of a water drop, and the recovery of the peeled piece were confirmed with a 30-fold stereo microscope and visually.

(Observation results)
There were no peeling residue, dents, traces of water droplets, and fine scratches on the printed wiring boards of Examples 1 to 4, and a clean surface state could be obtained. In addition, with respect to Examples 1 and 2, a phenomenon was observed in which the copper foil extended in the case of a thin board, but the printed wiring boards of Examples 3 and 4 had very good dimensional accuracy without extending the copper film. Met.

  Here, the difference between Examples 1 and 2 and Examples 3 and 4 is the difference in the apparatus for injecting dry ice particles. The injection apparatus used in Examples 1 and 2 is dry by the air pressure of the air compressor. Injecting ice particles, the injection device used in Examples 3 and 4 uses a blower to inject dry ice particles at a particle velocity rather than pressure. And the injection apparatus used in Examples 3 and 4 was better when the object to be cleaned was a thin plate.

  From the above results, according to the method for peeling an alkali-soluble photosensitive resin of the present invention, the alkali-soluble photosensitive resin can be easily peeled from the printed wiring board, and a clean processed surface is obtained. be able to.

According to the present invention, for example, in the production of a printed wiring board, the amount of industrial wastewater discharged can be significantly reduced.

Claims (11)

  An alkali-soluble photosensitive resin, wherein in the step of removing the alkali-soluble photosensitive resin, after the dry ice particles are sprayed onto the object to be cleaned, the substrate is cleaned with electrolytic acid water. Peeling method.   In the step of stripping the alkali-soluble photosensitive resin, after the dry ice particles are sprayed onto the object to be cleaned to which the photosensitive resin is adhered, washing with electrolytic alkaline water or an alkaline chemical solution is performed. Type photosensitive resin peeling method.   The method for peeling an alkali-soluble photosensitive resin according to claim 2, wherein the object to be cleaned is washed with electrolytic alkaline water or an alkaline chemical solution, and further washed with electrolytic acidic water.   4. When spraying dry ice particles onto the object to be cleaned, the periphery thereof is covered with a recovery cover, and the peeled and scattered photosensitive resin is recovered by suction from within the recovery cover. The peeling method of the alkali-soluble photosensitive resin as described in any one of these.   The alkali-soluble photosensitive resin peeling method according to claim 4, wherein at least a surface of the recovery cover is formed of a fluororesin or a silicon resin.   The suctioned photosensitive resin was selected from a recovery method using a centrifugal force by a cyclone flow, a recovery method using an air filter, and a recovery method for introducing and solidifying and precipitating electrolytic acid water in a water tank. The alkali-soluble photosensitive resin peeling method according to claim 4 or 5, wherein the alkali-soluble photosensitive resin is collected by at least one method.   7. The dry ice particle injection step uses dry ice particles having a diameter of 5 to 50 μm, an injection pressure of 0.01 to 5.0 MPa, and an injection time of 5 to 120 seconds. The peeling method of alkali-soluble type photosensitive resin as described in one.   The pH of the electrolytic acid water is 4.0 or less, and the residual chlorine concentration is 15 ppm or less. The method for stripping an alkali-soluble photosensitive resin according to any one of claims 1 and 3-7.   The method for peeling an alkali-soluble photosensitive resin according to any one of claims 2 to 8, wherein the pH of the electrolytic alkaline water is 10.0 or more and the oxidation-reduction potential is -50 mV or less.   The method for peeling an alkali-soluble photosensitive resin according to any one of claims 1 to 9, wherein dry ice particles are sprayed from both upper and lower surfaces while conveying the object to be cleaned.   10. The alkali-soluble composition according to claim 1, wherein one of the upper and lower surfaces of the object to be cleaned is supported by a belt-like transport mechanism, and dry ice particles are jetted from the remaining surface. Type photosensitive resin peeling method.

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