JP4151796B1 - Deburring and cleaning apparatus and deburring and cleaning method - Google Patents

Abstract

An object of the present invention is to provide a deburring cleaning apparatus and a deburring cleaning method capable of efficiently removing fine burrs generated at a processing site where a workpiece is mechanically processed with high deburring quality.
In deburring cleaning in which burrs generated on a cut surface of a resin substrate 8 are removed and cleaned, an ice blast nozzle 22 using a Laval nozzle is used to wash the frozen particles of cleaning water using cleaning water and compressed air. The cleaning medium 23 including the liquid droplets 23 b and the supercooled liquid droplets 23 b is generated and sprayed onto the resin substrate 8. Thereby, even when a fine burr of a metal having high ductility such as copper is targeted, it can be efficiently removed with high deburring quality.
[Selection] Figure 4

Description

  The present invention relates to a deburring cleaning apparatus and a deburring cleaning method for cleaning a processing part by removing a burr generated in a processing part obtained by mechanically processing a workpiece such as a substrate on which an electronic component is mounted.

Among mounting boards used in electronic equipment, small-diameter boards used in small equipment are handled in the form of so-called multi-sided boards in which multiple boards are built, and there are multiple component mounting operations such as screen printing and electronic component mounting. This is performed for all the substrates. The multi-sided board on which component mounting has been completed is divided into individual small-diameter boards in the board cutting process, resulting in a finished product. This substrate cutting is often performed by mechanically cutting a substrate by rotating a router as a shaft-shaped cutting tool or a dicing blade as a disk-shaped rotating tool (Patent Documents 1 and 2). reference). The prior art example shown in Patent Document 1 shows an example in which a plurality of stacked substrates are cut using a router. Patent Document 2 shows an example in which the position of a through hole provided in a substrate is cut by a dicing blade.
JP 2002-299790 A JP-A-11-16771

  A substrate used for mounting electronic components is generally a resin substrate such as a glass epoxy resin with circuit electrodes formed of a conductive metal film such as copper, forming a circuit through the thickness direction of the substrate. When it is necessary to do so, a foil-like copper film is formed not only on the surface of the substrate but also on the inner surface of the through hole provided through the substrate. In substrate cutting for dividing a multi-sided substrate into individual pieces, the circuit electrode on the substrate surface and the copper film on the inner surface of the through hole are mechanically cut simultaneously with the resin that is the substrate material. In the case, fine metallic burrs such as copper are generated.

  If such burrs remain as products, they may cause problems such as short-circuiting of circuit electrodes due to the burrs that have dropped off, and such burrs need to be removed as much as possible. However, metal used for circuit electrodes such as copper is rich in ductility, so it is difficult to remove it efficiently mechanically, and it is also possible to remove burrs with high deburring quality by manual deburring work using a brush or the like. It is difficult. For this reason, a deburring cleaning technique that enables efficient deburring after cutting the substrate with high deburring quality has been desired. Such a request is not limited to the field of mechanically cutting the mounting substrate, and is common even when fine burrs that are difficult to remove are generated in a processed part where the workpiece is mechanically processed.

  Therefore, an object of the present invention is to provide a deburring cleaning apparatus and a deburring cleaning method capable of efficiently removing fine burrs generated in a processing part obtained by mechanically processing a workpiece with high deburring quality. .

The deburring and cleaning apparatus of the present invention is a deburring and cleaning apparatus that removes and cleans the burrs generated in a processed part obtained by mechanically processing a workpiece, and the workpiece is a resin substrate on which electronic components are mounted, The burr includes a thin burr in which a part of the copper film is stretched into a fine bowl shape by mechanically cutting a copper film formed on the surface of the resin substrate or the inner surface of the through hole, A workpiece holding unit for holding a workpiece; a frozen cleaning medium spraying unit that sprays a cleaning medium containing frozen particles of cleaning liquid and supercooled droplets to the processing site via a cleaning nozzle; and A moving means for moving the workpiece relative to the work holding portion, and the freeze cleaning medium spraying means forms a cleaning liquid supply means for supplying the cleaning liquid and a main body of the cleaning nozzle, and narrows the internal flow path hole. A nozzle main body portion formed with a divergent portion that expands in the flow direction on the downstream side of the provided throat portion having a circular cross section; and a gas supply means that supplies compressed gas in the flow direction of the internal flow path hole. A cleaning liquid supply pipe that is provided in the nozzle main body and discharges the supplied cleaning liquid in the same direction as the flow direction, and the discharge port of the cleaning liquid supply pipe is separated from the inner wall side surface of the nozzle main body. Disposed near the throat portion, the flow rate of the compressed gas becomes a sound velocity in the throat portion, and the droplets generated by the cleaning liquid atomized by the flow of the compressed gas in the divergent portion are rapidly cooled. the frozen particles and droplets of supercooled state is generated in the washing deburring for injecting through the cleaning nozzle the cleaning medium relative to the machining area, before The fine cocoon-shaped burrs that remain without being removed by the collision of the frozen particles are wrapped by the droplets to produce a solid product in which the droplets are frozen and solidified. Remove .

Deburring cleaning method of the present invention, there is provided a deburring cleaning method for cleaning work is removed mechanically processed burrs that occurred machining area was, the work is a resin substrate on which the electronic component is mounted, The burr includes a narrow burr in which a part of the copper film is stretched into a fine bowl shape by mechanically cutting a copper film formed on the surface of the resin substrate or the inner surface of the through hole, A workpiece holding step for holding the workpiece on the workpiece holder, and a cleaning medium containing frozen particles of the cleaning liquid and supercooled droplets while moving the cleaning nozzle relative to the workpiece holder relative to the processing site A cleaning medium spraying step for spraying through the cleaning nozzle; and a deburring cleaning step for removing and cleaning the burrs generated in the processing site by the cleaning medium, The process includes supplying a compressed gas to a nozzle body portion having a divergent portion that forms a body portion of the cleaning nozzle and expands in a flow direction downstream of a throat portion having a circular cross section, and the throat portion A first step in which the flow velocity of the compressed gas is a sonic velocity; and a flow of the compressed gas in the nozzle body from an outlet of a cleaning liquid supply pipe disposed in the vicinity of the throat portion away from the inner side surface of the nozzle body. A second step of discharging the cleaning liquid in the same direction; and by rapidly cooling droplets generated by atomizing the cleaning liquid by the flow of the compressed gas in the divergent section, the frozen particles and the supercooled state A third step of generating the droplets of the liquid and a fourth step of jetting the cleaning medium from the cleaning nozzle to the processing site, wherein the deburring and cleaning step includes: A first step of removing by colliding the frozen particles to the burr, a second step of the fine whisker-like burrs remaining without being still removed by the collision of the frozen particles enveloping by the droplet , Including a third step of generating a solid matter containing the burr by freezing and solidifying the droplet, and a fourth step of peeling the solid matter by collision of the frozen particles.

  According to the present invention, in the deburring and cleaning that removes and cleans the burrs generated in the machining site where the workpiece has been mechanically processed, on the downstream side of the throat portion having a circular cross section provided by narrowing the internal flow path hole. Nozzle main body formed with a divergent portion that expands in the flow direction, gas supply means for supplying compressed gas in the flow direction of the internal channel hole, and provided in the nozzle main body in the same direction as the flow direction A cleaning liquid supply pipe that discharges the cleaning liquid, and the discharge port of the cleaning liquid supply pipe is disposed in the vicinity of the throat portion away from the inner wall side surface of the nozzle main body, and the flow rate of the compressed gas is sonic at the throat portion. The cleaning medium containing frozen particles and supercooled liquid droplets is sprayed onto the processing area by the freezing cleaning medium supply means configured as described above, so that high-quality burrs generated at the processing area can be obtained. In can be removed efficiently.

  Next, embodiments of the present invention will be described with reference to the drawings. 1 is a perspective view of a deburring and cleaning apparatus according to an embodiment of the present invention, FIG. 2 is a perspective view of a work holding portion of the deburring and cleaning apparatus according to an embodiment of the present invention, and FIG. 3 is an embodiment of the present invention. 4 is an explanatory view of a resin substrate to be deburred and cleaned by the deburring and cleaning apparatus of the embodiment, FIG. 4 is an explanatory view of the configuration of the nozzle head in the deburring and cleaning apparatus of one embodiment of the present invention, and FIG. FIG. 6 is a diagram illustrating the structure of a Laval nozzle used in the deburring and cleaning apparatus according to an embodiment of the present invention, and FIG. 8 is a partial cross-sectional view of a Laval nozzle used in the deburring and cleaning apparatus of the embodiment, and FIG. 8 is a process explanatory diagram of the deburring and cleaning method of one embodiment of the present invention.

  First, the overall configuration of the deburring and cleaning apparatus 1 will be described with reference to FIG. The deburring and cleaning apparatus 1 has a function of removing and cleaning burrs generated at a processing site obtained by mechanically processing a workpiece. In this embodiment, a resin substrate for mounting an electronic component is targeted as a workpiece, and a copper film formed as an electrode on the surface of this resin substrate or a through hole provided through the thickness direction of the resin substrate An example is shown in which deburring and cleaning is performed on a burr generated by mechanically cutting one or both of the copper films formed on the inner surface of the (through hole).

  In FIG. 1, a cover member 2 for closing a cleaning processing chamber 1b for deburring and cleaning is provided on the upper surface of a base 1a, and the deburring and cleaning described below is provided in the cleaning processing chamber 1b. The mechanism is arranged. An XY robot 3 in which an X table 3X and a Y table 3Y are combined is disposed on the upper surface of the base 1a. A resin substrate, which is a workpiece, is disposed on the upper surface of a horizontal moving table 4 coupled to the Y table 3Y. A work holding unit 5 for holding 8 is mounted. Above the workpiece holding unit 5, a nozzle head 6 for deburring and cleaning is held by a holding bracket (not shown).

  In the nozzle head 6 (see FIG. 4), fine ice particles or water droplets are held in the work holding unit 5 by the cleaning water (cleaning liquid) and compressed air (compressed gas) supplied from the working fluid supply unit 7. An ice blast nozzle (cleaning nozzle) for spraying and cleaning the resin substrate 8 to be cleaned is equipped. By driving the XY robot 3, the work holding unit 5 moves in the X direction and the Y direction, whereby the resin substrate 8 held by the work holding unit 5 can be moved relative to the nozzle head 6. it can.

  Therefore, the XY robot 3 is a moving means for moving the ice blast nozzle as a cleaning nozzle relative to the work holding unit 5. Here, a configuration is adopted in which the nozzle head 6 is fixedly arranged and the resin substrate 8 is horizontally moved. However, even if the workpiece holding unit 5 is fixedly arranged and the nozzle head 6 is moved by an XY robot. Good.

  An opening 2a is provided on the front surface of the cover member 2 corresponding to the movement range of the work holding unit 5, and a cover door 9 is mounted on the opening 2a so as to be horizontally movable. The cover door 9 is driven by a door opening / closing cylinder 9a, whereby the opening 2a is opened and closed. Loading and unloading of the resin substrate 8 into and from the cleaning processing chamber 1b is performed by the substrate transfer arm 10 provided on the front surface of the opening 2a.

  Next, the structure of the work holding unit 5 will be described with reference to FIG. The work holding unit 5 has a configuration in which a holding table 11 on which the resin substrate 8 is placed is stacked on the upper surface of the cooling unit 12. A guide member 13 is provided on the upper surface of the holding table 11, and the resin substrate 8 placed on the holding table 11 is positioned by the guide member 13. Further, suction holes 11 a are formed on the upper surface of the holding table 11 corresponding to the arrangement of the individual substrates 8 a constituting the resin substrate 8, and vacuum suction is performed from the suction holes 11 a inside the holding table 11. An internal suction hole 11b (see FIG. 4) is provided.

  With the resin substrate 8 placed on the holding table 11, vacuum suction is performed from the internal suction holes 11 b by the vacuum suction source 29 (see FIG. 5), whereby the individual substrates 8 a of the resin substrate 8 are vacuum-adsorbed. It can be held. A refrigerant circulation hole 12a is provided inside the cooling unit 12, and the resin substrate 8 held on the holding table 11 is set in advance by circulating a refrigerant such as an antifreeze liquid in the refrigerant circulation hole 12a. Cooled to temperature.

  Next, with reference to FIG. 3, the resin substrate 8 to be deburred and cleaned and the state of occurrence of burrs in the resin substrate 8 will be described. The resin substrate 8 shown here is a so-called multi-sided substrate in which a small circuit board used for a small device is formed on the same parent substrate, and is made of a resin such as a glass epoxy resin. Here, after completion of component mounting work such as board cutting or screen printing or electronic component mounting, which is performed in the pre-process of component mounting work, it is divided into individual boards 8a as finished products. The thing in the state which finished the board | substrate cutting is object.

  This substrate cutting is performed using a cutting tool such as a dicing blade or a router. In the example shown here, for convenience of handling, the individual substrates 8a are not completely separated but are partially connected. It is said. That is, as shown in FIG. 3, continuous cut grooves 14 are processed in the horizontal direction in the resin substrate 8, and intermittent cut grooves 15 are processed in the vertical direction for each individual substrate 8a. The individual substrates 8 a can be transported as one piece while maintaining the overall shape of the resin substrate 8 and can be held by the work holding unit 5.

  As shown in the enlarged view of FIG. 3A, the continuous cutting groove 14 is processed in a form that cuts through holes 16 provided through the resin substrate 8 together with the electrodes 17 formed on the surface of the resin substrate 8. Has been. In the cut surface 14a formed by the groove processing, a conductive metal film (here, a copper film) integrally formed with the electrode 17 on the inner surface of the through hole 16 is made of a resin such as a glass epoxy resin. The burrs are generated by cutting together with the main body of the substrate 8.

  This burr is a large burr (hereinafter referred to as “surface”) formed into a thin film in a form having a planar expansion in which the cutting cross section 17a is extended by the ductility of the metal in the cutting direction during cutting with a cutting tool. Burr generation forms (occurrence site, large size) such as a narrow burr (hereinafter abbreviated as “burr 18b”) in which a part of the electrode 17 is stretched into a fine corrugated shape. A variety of burrs with different adhesion strengths are generated. Further, when such burrs are scattered as fragments and attached in the vicinity of the cut portion, they remain as attached burrs 18c.

  If such burrs remain as products, they may cause problems such as short-circuiting of circuit electrodes due to dropped burrs. Therefore, it is necessary to remove burrs generated during substrate cutting as much as possible. The metal used for the electrode is rich in ductility and easy to bend, and it is often difficult to remove it efficiently by mechanically applying an external force. In the present embodiment, deburring and cleaning are performed by the method described below for such burrs that have different burr generation forms and adhesion characteristics and are difficult to completely remove.

  FIG. 4 shows the configuration of the nozzle head 6 used for this deburring cleaning and the holding form of the resin substrate 8 in the work holding unit 5. As described above, the resin substrate 8 placed on the holding table 11 of the work holding unit 5 is sucked and held on the holding table 11 by the suction holes 11a provided for the individual substrates 8a. The resin substrate 8 is cooled via the holding table 11 by circulating the cooling medium in the refrigerant circulation hole 12 a provided in the substrate.

  By this cooling effect, prior to the deburring and cleaning operation, the temperature of the resin substrate 8 can be reduced as much as possible, and deburring and cleaning by ice blasting described below can be performed efficiently. That is, the work holding unit 5 includes a cooling unit 12 that is a pre-cooling means for cooling the resin substrate 8 that is a work in advance. Depending on the type of the target workpiece, pre-cooling may not be necessary, and the cooling unit 12 is not an essential component.

  The nozzle head 6 has a configuration in which an ice blast nozzle 22 is mounted on a nozzle block 6a. The ice blast nozzle 22 is a resin in which a cleaning medium 23 including cleaning water supplied from the working fluid supply unit 7 and frozen particles 23 a and droplets 23 b generated from compressed air is held in the work holding unit 5. Injected onto the substrate 8. The ice blast nozzle 22 is held in a predetermined posture with respect to the nozzle head 6, that is, the incident angle of the cleaning medium 23 ejected from each on the surface 8 b of the resin substrate 8 is an angle α. The angle α is generally in the range of 30 degrees to 60 degrees, but the detailed angle is set based on a trial result obtained by actually performing a deburring cleaning test on the individual resin substrates 8.

  Next, the configuration of a piping system such as the working fluid supply unit 7 will be described with reference to FIG. In FIG. 5, the vacuum suction source 29 is connected to the holding table 11, and the resin substrate 8 is sucked and held by the holding table 11 by operating the vacuum suction source 29. The refrigerant circulation unit 30 is connected to the cooling unit 12 via the refrigerant supply pipe 30a and the return pipe 30b, and has a function of cooling the refrigerant such as antifreeze liquid and circulating it to the cooling target part. The cooling operation of the resin substrate 8 by the cooling unit 12 is controlled by opening and closing the open / close valve 31 interposed in the refrigerant supply pipe 30a.

  The working fluid supply unit 7 is supplied with cleaning water used as a cleaning liquid and compressed air used as an ejection medium from a cleaning water supply source 32 and an air supply source 33, respectively. A piping system for supplying cleaning water and compressed air to the ice blast nozzle 22 will be described. An air supply pipe 33a connected to the air supply source 33 is connected to the ice blast nozzle 22, and a regulator 41, a filter 42, a temperature / humidity adjuster 43, and an open / close valve 45 are interposed in the air supply pipe 33a. Yes. By controlling the opening / closing valve 45 to open / close, the compressed air supplied to the ice blast nozzle 22 is on / off controlled.

  The regulator 41 adjusts the pressure of the compressed air supplied to the air supply pipe 33a, and the filter 42 filters and removes foreign matter from the supplied compressed air. The temperature and humidity adjuster 43 freezes and removes moisture by cooling the compressed air, and adjusts the temperature of the compressed air to a predetermined temperature. The temperature sensor 44 connected to the air supply pipe 33a detects the temperature of the supplied compressed air. By operating the regulator 41, the pressure supplied to the ice blast nozzle 22 can be set to a predetermined pressure. Here, the compressed air is set to a specified pressure selected from a pressure range of 0.2 MPa to 1 MPa.

  Further, the humidity and temperature of the compressed air supplied to the ice blast nozzle 22 can be set to a desired range by setting the operation of the temperature / humidity adjuster 43. Here, as the set temperature / humidity, the temperature is 0 ° C. to 40 ° C. (preferably 10 to 30 ° C.), and the humidity is −20 ° C. to 0 ° C. (preferably −15 ° C. to −5 ° C.) in terms of dew point temperature. Selected from the condition range. Each element interposed in the air supply source 33 and the air supply pipe 33a described above constitutes a gas supply means for supplying compressed air, which is a compressed gas, to the ice blast nozzle 22.

  The cleaning water supply pipe 32a is connected to a fixed discharge pump 46, and the pump 46 discharges the cleaning water supplied through the cleaning water supply pipe 32a in a fixed quantity. The discharged cleaning water is supplied to the cleaning water cooling unit 50 through the discharge water piping 46a. A flow rate sensor 47, a check valve 48, and a filter 49 are provided in the discharge water pipe 46a. The flow rate sensor 47 detects the flow rate of the cleaning water flowing through the discharge water piping 46a. The check valve 48 prevents the backflow of the washing water, and the filter 49 filters and removes foreign matters in the washing water.

  A refrigerant supply pipe 30a and a return pipe 30b are connected to the refrigerant container 50a provided in the washing water cooling unit 50 via an opening / closing valve 52. By opening the opening / closing valve 52, the inside of the refrigerant container 50a is connected. A refrigerant 51 such as an antifreeze liquid cooled by the refrigerant circulation unit 30 circulates. A cooling pipe 50b communicating with the discharge water pipe 46a is disposed in the refrigerant container 50a. The cooling pipe 50b is immersed in the refrigerant 51 and is always cooled by the refrigerant 51.

  With the above configuration, the wash water fed from the discharge water pipe 46a passes through the cooling pipe 50b and is set within a temperature range of −5 ° C. to 30 ° C. (preferably 0 ° C. to 20 ° C.). It is cooled to a set temperature (about 5 ° C. in the present embodiment), and is supplied to the ice blast nozzle 22 through the cold water supply pipe 50c in this state. At this time, by controlling the drive of the pump 46 by a control unit (not shown) based on the detection result of the flow sensor 47, the ice blast nozzle 22 is always supplied with cold water having a preset predetermined flow rate. In the above-described configuration, each element provided in the piping system from the cleaning water supply source 32 to the cold water supply piping 50c constitutes a cleaning liquid supply unit that supplies cleaning water, which is a cleaning liquid, to the ice blast nozzle 22.

  Next, the structure of the ice blast nozzle 22 and the manner in which the cleaning medium 23 is ejected by the ice blast nozzle 22 will be described with reference to FIG. The ice blast nozzle 22 is already known, and its configuration is described in detail in Japanese Patent Application Laid-Open No. 2007-73615.

  As shown in FIG. 6A, the ice blast nozzle 22 is mainly composed of a cylindrical nozzle body 22a, and an internal flow path hole 24 is formed through the nozzle body 22a in the longitudinal direction. . The upstream side of the internal flow path hole 24 is an introduction part 24a to which compressed air (arrow a) is introduced by connecting an air supply pipe 33a. The compressed air supplied to the introduction unit 24a is adjusted by the temperature / humidity adjuster 43 so as to be maintained at a predetermined temperature / humidity set in advance.

  On the downstream side of the introduction portion 24a, a convergent portion 24b in which the flow passage diameter of the internal flow passage hole 24 is narrowed along the flow direction, a throat portion 24c in which the flow passage diameter is narrowed to the smallest, and a divergent in which the flow passage diameter increases. The part 24d and the acceleration cooling part 24e whose flow path diameter gradually increases are sequentially provided in the flow direction of the compressed air. The opening where the accelerated cooling unit 24e reaches the end of the nozzle main body 22a is an ejection port 22b that ejects the cleaning medium 23. Further, a rectifying plate 27 is provided on the upstream side of the convergent portion 24b, whereby the flow of compressed air can be rectified to reduce pressure loss, and the supply of compressed air to the throat portion 24c can be smoothly performed. It can be carried out.

  That is, the ice blast nozzle 22 configured as described above forms a Laval nozzle having a convergent portion 24b, a throat portion 24c, and a divergent portion 24d. The nozzle main body 22a is formed of a resin such as PTFE resin or metal, and is manufactured by integrally molding one that is molded integrally or divided as appropriate. The diameter of the throat portion 24c is appropriately set, for example, from a range of 3 to 10 mm, and the distance from the throat portion 24c to the injection port is set to a distance sufficient to accelerate the compressed air in a range of 100 to 300 mm, for example.

  The shapes of the convergent part 24b, the throat part 24c and the divergent part 24d are obtained by appropriately adiabatically expanding the supplied compressed air by the characteristic curve method so that the supplied compressed air is cooled to a low temperature by adiabatic expansion. It is designed in a shape that can be cooled down to a low temperature by atomizing the washing water. In the Laval nozzle designed by the characteristic curve method, even if the supplied compressed air has a subsonic velocity at the convergent portion 24b, the throat portion 24c having a small cross-sectional area has a sound velocity, and the divergent portion 24d has a large cross-sectional area. The pressure drops and becomes supersonic.

  In other words, the pressure of the compressed air is adjusted so as to be as high as the sound speed at the throat portion 24c, and then supplied to the convergent portion 24b at a subsonic speed (for example, about 50 m / sec) and accelerated by the convergent portion 24b. The sound velocity (about 330 m / sec) is obtained at the throat portion 24c, and further accelerated by the divergent portion 24d, for example, to a supersonic velocity of about 400 to 500 m / sec. Due to the adiabatic expansion that occurs with this acceleration, the temperature of the compressed air decreases to about −60 ° C. to −110 ° C.

  A cleaning liquid supply pipe 25 that discharges cleaning water in the same direction as the flow of compressed air is provided on the upstream side of the throat portion 24c. Here, the temperature of the washing water is adjusted by the washing water cooling unit 50 so as to be the prescribed water temperature set in the above-described temperature range, and is supplied through the cold water supply pipe 50c in a prescribed amount set in advance. . The supplied cleaning water is discharged from the discharge port at the tip of the cleaning liquid supply pipe 25 to become fine droplets 26, and flows with the compressed air to the downstream side at a high speed.

  As shown in FIG. 7A, the discharge port of the cleaning liquid supply pipe 25 is positioned near the throat portion 24c and away from the inner wall surface of the internal flow path hole 24, for example, upstream and downstream from the center of the throat portion 24c. Are disposed within a discharge port arrangement range (see a range R indicated by a broken line frame) that is within a range of a length five times the inner diameter d of the throat portion 24c. In this way, by disposing the discharge port of the cleaning liquid supply pipe 25 in the vicinity of the throat portion 24c away from the inner wall surface of the nozzle main body portion 22a, the droplet 26 in which the discharged cleaning water is atomized becomes the nozzle main body portion 22a. It becomes difficult to receive the influence of the boundary layer area | region formed in the inner wall surface. Thereby, the speed reduction of the droplet 26 can be suppressed and sufficiently accelerated, and the ability as a cleaning medium can be improved.

  Here, the significance of positioning the discharge port of the cleaning liquid supply pipe 25 within the above-described discharge port arrangement range will be described. When the discharge port is arranged on the upstream side of the discharge port arrangement range, the cleaning water is discharged into the compressed air having a low flow rate and a high temperature. Efficiency also decreases. Further, when the discharge port is arranged on the downstream side of the discharge port arrangement range, the distance from the nozzle main body portion 22a to the injection port 22b becomes short, and the generated droplets cannot be sufficiently cooled. On the other hand, by positioning the discharge port within the above-described discharge port arrangement range, the particle size of the generated droplet is reduced, and sufficient cooling is performed in the process of flowing the generated droplet downstream. It is possible to secure a distance for this.

  A process of generating the cleaning medium in the ice blast nozzle 22 will be described. The flow of compressed air supplied to the introduction portion 24a at a set pressure (for example, 0.5 Mp) is first rectified by the rectifying plate 27, then accelerated by the convergent portion 24b (arrow b), and the throat portion at a flow rate of about the speed of sound. Pass 24c. Then, by moving from the throat portion 24c into the divergent portion 24d, the pressure is lowered and further accelerated (arrow c), and the temperature is lowered to about −110 ° C. by adiabatic expansion as described above. Then, the droplets 26 discharged from the discharge port of the cleaning liquid supply pipe 25 and atomized by the flow of compressed air are rapidly cooled by the compressed air whose temperature has decreased, and the frozen particles 23a and the droplets 26 are frozen. Even at 0 ° C. or lower, both or one of the droplets 23b existing in a supercooled droplet state is generated. That is, here, a solid-liquid two-phase spray particle group including the frozen particle 23a cleaning liquid and the droplet 23b is formed.

  Then, the cleaning medium 23, which is a flow of compressed air containing such solid-liquid two-phase spray particles, flows at a high speed toward the downstream side while being accelerated in the accelerating cooling unit 24e that gradually expands (arrow d). Injected from the injection port 22 b of the ice blast nozzle 22. The degree of diameter expansion in the accelerated cooling portion 24e is determined in consideration of the thickness of the boundary layer region formed near the inner wall surface of the internal flow path hole 24. In general, in the flow of fluid in a circular pipe, a boundary layer in which the flow state changes near the inner wall surface of the pipe, and the flow velocity decreases in this boundary layer region. In the case of a flow in a circular pipe having a constant pipe inner diameter, the boundary layer region expands in the vicinity of the pipe outlet, and as a result, the flow velocity decreases near the center of the flow. On the other hand, by providing the acceleration cooling part 24e that gradually expands in the flow direction in consideration of the boundary layer region, it is possible to suppress the influence of the decrease in the flow velocity in the boundary layer region, and to increase the speed even in the vicinity of the injection port 22b. The flow can be secured in a wide range.

  When designing the ice blast nozzle 22, the attached burr 18 c (as the effective diameter D having a deburring and cleaning action by the cleaning medium 23 is set to the required processing width W shown in FIG. 6B, that is, the cutting width B of the resin substrate 8. The dimensions of each part of the ice blast nozzle 22 are set so as to obtain an effective diameter D that can sufficiently cover the width W including the cleaning target range in which burr adhesion occurs (see FIG. 3). Further, by adjusting the temperature / humidity of the compressed air by the temperature / humidity adjuster 43 provided in the air supply pipe 33a and the temperature of the washing water by the washing water cooling unit 50, the frozen particles 23a and the droplets 23b are adjusted. It is possible to set the ratio to a desired ratio.

  In addition, as a form of the cleaning liquid supply pipe 25, a double pipe structure may be used so that a different kind of gas from the cleaning water can be mixed and injected together with the cleaning water. Here, the example which uses the simplest compressed air as gas to mix is shown. That is, as shown in FIG. 7 (b), the gas supply pipe 25B is inserted into the cleaning liquid supply pipe 25A having a diameter larger than that of the cleaning liquid supply pipe 25 shown in FIG. The gas supply pipe 25 </ b> B is connected to the gas supply pipe 28 connected to the air supply source 33. When the cleaning water is discharged from the discharge port of the cleaning liquid supply pipe 25A, the compressed air is simultaneously ejected from the gas supply pipe 25B and mixed, whereby the action of atomizing the discharged cleaning water is increased and the droplet 26 is discharged. The particle size of the can be made finer.

  Then, by adjusting the pressure and flow rate of the compressed air ejected from the gas supply pipe 25B, it is possible to obtain droplets 26 having a desired particle size. At this time, by using finer droplets 26, the cooling rate can be increased and the ratio of the frozen particles 23a in the cleaning medium 23 can be increased. This is combined with the temperature / humidity of the compressed air and the temperature adjustment of the cleaning water. Thus, the ratio between the frozen particles 23a and the droplets 23b can be adjusted. In addition, as long as it does not have a property which pollutes a washing | cleaning target object instead of compressed air as gas injected from the gas supply pipe | tube 25B, you may make it use other types of gas, such as nitrogen gas.

  In the above configuration, the cleaning liquid supply means, the gas supply means, and the ice blast nozzle 22 are processed by cutting the resin substrate 8 from the cleaning medium containing the frozen particles 23a of the cleaning water as the cleaning liquid and the supercooled droplets 23b. A freeze cleaning medium spraying means for spraying the part is configured. The freeze cleaning medium injection means constitutes the main body of the ice blast nozzle 22 and the above-described cleaning liquid supply means for supplying the cleaning water, and has a circular section throat portion 24c provided by narrowing the internal flow path hole 24. Nozzle body 22a having a divergent portion 24d that expands in the flow direction on the downstream side of the nozzle, and a cleaning liquid supply that is provided in the nozzle body portion 22a and discharges cleaning water as a cleaning liquid supplied in the same direction as the flow direction It has a configuration having a tube 25.

  Further, in the internal structure of the ice blast nozzle 22 described above, the discharge port of the cleaning liquid supply pipe 25 is disposed in the vicinity of the throat portion 24c separated from the inner wall side surface of the nozzle main body portion 22a, and the flow rate of the compressed air is adjusted to the sound velocity in the throat portion 24c. Thus, the flow of compressed air in the divergent portion 24d rapidly cools the droplets 26 generated by atomizing the discharged cleaning water, thereby generating frozen particles 23a and supercooled droplets 23b. It has a form. In the example shown in the present embodiment, the most inexpensive and easy-to-use water (cleaning water) is used as the cleaning liquid used for deburring cleaning. However, a liquid suitable for cleaning other than water, such as alcohol, is used as the cleaning liquid. It may be used as

  As described above, the ice blast nozzle 22 using the Laval nozzle configured as described above can generate the cleaning medium 23 including the frozen particles 23a and the supercooled droplets 23b only by supplying the compressed air and the cleaning water. In addition to being possible, as described above, the droplets 26 atomized to a predetermined particle size can be sufficiently accelerated and cooled, and the ratio between the frozen particles 23a and the droplets 23b can be set to a desired value. It has an unprecedented excellent characteristic that it can be set to a ratio. By using the ice blast nozzle 22 having such characteristics in a deburring and cleaning apparatus, as described below, a cleaning medium suitable for deburring that targets fine burrs of a metal having high ductility such as copper is provided. It can be generated efficiently and at low cost.

  The ice blast nozzle 22 has a shape in which the nozzle body 22a constitutes a Laval nozzle, but the nozzle body 22a only needs to have a divergent portion 22d on the downstream side of the throat portion 24c. It is not an essential requirement in the present invention to provide the convergent part 22b on the upstream side of the part 24c.

  Next, a deburring cleaning method for removing and cleaning the burrs generated in the processed portion of the resin substrate 8 after the cutting process will be described. That is, here, the target workpiece is a resin substrate on which electronic components are mounted, and the burr to be removed is generated by mechanically cutting the copper film formed on the surface of the resin substrate 8 or the inner surface of the through hole. It is. As described above, in the groove processing in which the through hole 16 provided through the resin substrate 8 is cut, various burrs having different burrs are generated, such as the surface burrs 18a and the bristle burrs 18b.

  In the deburring / cleaning method by the deburring / cleaning apparatus shown in the present embodiment, since the cleaning medium 23 contains a large number of fine frozen particles 23a and droplets 23b, the deburring / cleaning method surely prevents fine deburring. While these frozen particles and water droplets can be used to reliably remove burrs, these frozen particles 23a and water droplets 23b are ejected in a dispersed state, so that they are shown in FIG. It is not always effective from the viewpoint of a sufficient striking force for removing burrs with respect to burrs generated while maintaining a strong adhesive force such as the surface burr 18a.

  If you want to set deburring conditions that include such burrs in the removable range, you need to set the injection amount and pressure higher and set the processing speed low, which results in a reduction in deburring work costs. The result is a rise and a reduction in work efficiency. For this reason, when the burrs generated on the target resin substrate 8 include those having a strong adhesive force such as the above-described surface burrs with a high probability, the deburring and cleaning operation by the above-described ice blast nozzle 22 is performed. Prior to removing the burrs generated at the processing site from the burrs that are difficult to remove by the ice blast nozzle 22, or reducing the strength of the burrs to facilitate the deburring by the ice blast nozzle 22. It is desirable to perform processing. In this pretreatment, since fine burrs are not to be removed, a rough method in which the deburring external force is roughly applied may be used.

  As such a pretreatment method, a method using a brush, a method using laser light irradiation, a method using abrasive blasting, a method using a water jet, or the like can be used. The pretreatment device for executing these pretreatments may be provided separately as a pre-processing device of the deburring and cleaning apparatus shown in FIG. 1, and deburring and cleaning shown in FIG. 1 such as abrasive blast and water jet. In the case of pretreatment means of a system that can be integrated into the apparatus, it can be incorporated in the same cleaning processing chamber 1b.

  In other words, abrasive blasting and water jet blast nozzles and water jet nozzles are held so that they can be sprayed onto the resin substrate 8 held by the work holding unit 5, and abrasives disposed inside or outside the deburring and cleaning apparatus. It is configured such that abrasive grains and high-pressure water as a deburring cleaning medium can be supplied from a grain supply device or a high-pressure water generator to a blast nozzle or water jet nozzle. In this case, the deburring and cleaning apparatus removes burrs that are difficult to deburr by the ice blast nozzle 22 from the burrs generated at the processing site prior to the deburring and cleaning operation by the ice blast nozzle 22, or increases the strength of the burrs. It has a form provided with pretreatment means for performing pretreatment for weakening and facilitating deburring and cleaning by the ice blast nozzle 22.

  Next, the deburring cleaning operation for the resin substrate 8 by the ice blast nozzle 22 will be described with reference to FIG. Here, when a strong burr that is difficult to remove by the ice blast nozzle 22 is not generated at the processing site of the target resin substrate 8, or such a burr is removed by pretreatment, or the strength of the burr is reduced. An example in which the resin substrate 8 after the deburring and cleaning by the blast nozzle 22 is facilitated will be described.

  First, the resin substrate 8 after the cutting process shown in FIG. 3 is held by the work holding unit 5 (work holding process). At this time, the resin substrate 8 is cooled to a preset precooling temperature (0 to 10 ° C.) by the precooling means provided in the work holding unit 5. In the case where the above-described pretreatment means is integrally provided in the deburring / cleaning apparatus, the above-described pretreatment is performed prior to deburring / cleaning by the ice blast nozzle 22 (pretreatment step).

  Thereafter, the deburring cleaning operation for the resin substrate 8 by the nozzle head 6 is started. That is, while moving the ice blast nozzle 22 relative to the work holding unit 5, the cleaning medium 23 including the frozen particles 23a and the droplets 23b is sprayed to the processing site via the ice blast nozzle 22 (cleaning medium spraying step). ).

  The details of this cleaning medium injection process will be described. First, compressed air is supplied from the air supply pipe 50c into the introduction part 24a of the nozzle body 22a, and the flow rate of the compressed air is set to the sonic speed in the throat part 24c (first step). Next, cleaning water is discharged in the same direction as the flow of compressed air in the nozzle body 22a from the discharge port of the cleaning liquid supply pipe 25 disposed in the vicinity of the throat portion 24c away from the inner side surface of the nozzle body 22a (first). 2 steps). Next, by rapidly cooling the droplet 26 generated by atomizing the cleaning water by the flow of compressed air in the divergent portion 24d, the droplet 26b in the supercooled state of the frozen particle 23a cleaning liquid supply pipe is generated ( (3rd process). Next, as shown in FIG. 8A, the cleaning medium 23 including the frozen particles 23a and the droplets 23b is ejected from the ejection port 22b of the ice blast nozzle 22 to the processing site of the resin substrate 8 (fourth). Process). Then, the ejected cleaning medium 23 removes and cleans the burrs generated at the processing site (deburring cleaning process).

  The details of this deburring and cleaning process will be described. First, the frozen particles 23a are removed by colliding with the burrs (first step). That is, as shown in FIG. 8A, the collision force of the frozen particles 23a is applied to the surface burr 18a which is developed in a planar shape and has a large pressure receiving area, and drops off. Next, the soot burrs 18b that remain without being removed by the collision of the frozen particles 23a are encapsulated by the droplets 23b (second step). That is, as shown in FIG. 8 (b), the droplet 23b is attached to the burrs 18b that are narrow and have a small pressure receiving area and are difficult to remove by the collision force of the frozen particles 23a, and the droplets 23b wrap the burrs 18b. . At this time, since the droplet 23b is supercooled, it rapidly freezes and solidifies when it comes into contact with the fine burrs 18b.

  Then, the plurality of droplets 23b adhere and accumulate on the burrs 18b, so that the burrs 18b are encapsulated by the frozen bodies 23c in which the droplets 23b are frozen and solidified to generate a solid material 34 containing the burrs 18b (third). Process). Thereafter, as shown in FIG. 8C, the solid material 34 is peeled off by the collision of the frozen particles 23a (fourth step). Since such a solid material 34 has a surface spread, it is larger in area than the size of the paddle burr 18b itself, and as shown in FIG. The burrs 18b are easily peeled off and removed from the burrs, and the burrs 18b are removed from the resin substrate 8.

  At the same time, fine foreign matter existing in the vicinity of the processing site in cutting the substrate, such as an adhesion burr 18c attached to the upper surface of the resin substrate 8 shown in FIG. Wrapped up and removed. That is, here, in the removal of the fine foreign matter such as the fine burrs 18b generated on the resin substrate 8, the solid matter generated by freezing and solidifying the supercooled droplets 23b enclosing the fine foreign matters such as the burrs 18b. 34 is peeled off from the burr generation part of the resin substrate 8.

  As described above, the ice blast nozzle 22 configured as described above is employed in a deburring and cleaning apparatus that targets fine deburring that is difficult to remove, such as deburring and cleaning after cutting the resin substrate 8. Therefore, the deburring operation can be efficiently performed with high deburring quality for a fine burr of a metal having a high ductility such as copper.

  The deburring and cleaning apparatus and the deburring and cleaning method of the present invention have the effect that fine burrs generated in a machining part where a workpiece is mechanically processed can be efficiently removed with high deburring quality, and a resin substrate. It can be used in the field of deburring and cleaning for burrs that are difficult to remove, such as burrs on copper films generated by mechanically cutting the burrs.

The perspective view of the deburring cleaning apparatus of one embodiment of this invention The perspective view of the workpiece holding part of the deburring cleaning apparatus of one embodiment of this invention Explanatory drawing of the resin substrate used as the deburring cleaning object by the deburring cleaning apparatus of one embodiment of this invention Structure explanatory drawing of the nozzle head in the deburring cleaning apparatus of one embodiment of this invention Piping system diagram of working fluid supply unit in deburring and cleaning apparatus of one embodiment of the present invention Structure explanatory drawing of the Laval nozzle used for the deburring cleaning apparatus of one embodiment of this invention The fragmentary sectional view of the Laval nozzle used for the deburring cleaning apparatus of one embodiment of the present invention Process explanatory drawing of the deburring cleaning method of one embodiment of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Deburring and cleaning apparatus 3 XY robot 5 Work holding part 6 Nozzle head 7 Working fluid supply part 8 Mounting board 8a Individual board 11 Holding table 12 Cooling unit 16 Through hole 17 Electrode 18a Surface burr 18b 髭 Burr 22 Ice blast nozzle (cleaning) nozzle)
23 Washing medium 23a Frozen particle 23b Droplet 32 Washing water supply source 33 Air supply source 34 Solid matter 46 Pump 50 Washing water cooling unit

Claims (4)

It is a deburring and cleaning device that removes and cleans burrs that have occurred in the machined part of a workpiece,
The workpiece is a resin substrate on which electronic components are mounted, and the burrs are formed by finely cutting a copper film formed on the surface of the resin substrate or the inner surface of the through-hole so that a part of the copper film is fine. Including a narrow burr stretched like a bowl,
A workpiece holding unit that holds the workpiece, a frozen cleaning medium spraying unit that sprays a cleaning medium containing frozen particles of cleaning liquid and supercooled droplets onto the processing site via a cleaning nozzle; and the cleaning nozzle A moving means for moving relative to the work holding unit,
The frozen cleaning medium injection means forms a main body part of the cleaning nozzle and a cleaning liquid supply means for supplying the cleaning liquid, and flows in a flow direction downstream of a throat portion having a circular cross section provided by narrowing an internal flow path hole. A nozzle main body portion formed with a divergent portion that expands in diameter, gas supply means for supplying compressed gas in the flow direction of the internal flow path hole, and provided in the nozzle main body portion in the same direction as the flow direction. A cleaning liquid supply pipe for discharging the supplied cleaning liquid;
The discharge port of the cleaning liquid supply pipe is disposed in the vicinity of the throat part away from the inner wall side surface of the nozzle body part, and the flow rate of the compressed gas becomes the speed of sound in the throat part,
The droplets generated by atomizing the cleaning liquid by the flow of the compressed gas in the divergent portion are rapidly cooled to generate the frozen particles and the supercooled droplets ,
In cleaning deburring in which the cleaning medium is sprayed to the processing site via a cleaning nozzle, the fine ridge-shaped burrs that remain without being removed by the collision of the frozen particles are wrapped with the droplets. A deburring and cleaning apparatus, wherein the liquid droplets generate a solid material frozen and solidified, and the solid material is separated by collision of the frozen particles . Prior to the deburring and cleaning operation by the freeze cleaning medium spraying means, burrs that are difficult to be deburred by the freeze cleaning medium spraying means are removed from the burrs generated at the processing site, or the strength of the burrs is reduced. The deburring and cleaning apparatus according to claim 1, further comprising preprocessing means for performing preprocessing for facilitating deburring and cleaning by the spraying means. A deburring and cleaning method that removes and cleans burrs generated in a machined part of a workpiece.
The workpiece is a resin substrate on which electronic components are mounted, and the burrs are formed by finely cutting a copper film formed on the surface of the resin substrate or the inner surface of the through-hole so that a part of the copper film is fine. Including a narrow burr stretched like a bowl,
A workpiece holding step for holding the workpiece on the workpiece holder, and a cleaning medium containing frozen particles of the cleaning liquid and supercooled droplets while moving the cleaning nozzle relative to the workpiece holder relative to the processing site A cleaning medium spraying step for spraying through the cleaning nozzle, and a deburring cleaning step for removing and cleaning the burrs generated in the processing site by the cleaning medium,
Further, in the cleaning medium injection step, a compressed gas is supplied to a nozzle main body portion having a divergent portion that forms a main body portion of the cleaning nozzle and expands in a flow direction downstream of a throat portion having a circular cross section, A first step in which the flow rate of the compressed gas is a sonic velocity in the throat portion;
A second step of discharging the cleaning liquid in the same direction as the flow of the compressed gas in the nozzle main body from an outlet of a cleaning liquid supply pipe disposed in the vicinity of the throat portion away from the inner side surface of the nozzle main body;
A third step of generating the frozen particles and the supercooled droplets by rapidly cooling the droplets generated by atomizing the cleaning liquid by the compressed gas flow in the divergent section;
A fourth step of injecting the cleaning medium from the cleaning nozzle to the processing site,
The deburring and cleaning step includes a first step of removing the frozen particles by colliding with the burrs, and the fine wrinkle-like burrs remaining without being removed by the collision of the frozen particles. A second step of wrapping with the droplets, a third step of generating a solid matter containing the burr by freezing and solidifying the droplet, and a fourth step of peeling the solid matter by collision of the frozen particles. A deburring cleaning method characterized by that. Prior to the cleaning medium spraying step, burrs that are difficult to be deburred by the frozen cleaning medium spraying means are removed from the burrs generated at the processing site, or the burrs are weakened and deburred by the frozen cleaning medium spraying means. The deburring cleaning method according to claim 3 , further comprising a pretreatment step of performing a pretreatment for facilitating the process.

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