JP7574606B2 - Blasting device and blasting method - Google Patents

Description

This disclosure relates to a blast processing device and a blast processing method.

A blasting method is known in which an abrasive is sprayed from a nozzle along with compressed air to form deep spaces such as holes and grooves in a workpiece. In this type of blasting method, a dry film with a mask pattern is formed on the workpiece, and an abrasive is sprayed from the nozzle to remove the areas of the workpiece that are exposed from the dry film, forming spaces in the workpiece.

In blast processing methods, particularly when performing very fine processing such as when the workpiece is a printed circuit board, high processing accuracy is required for the spaces. As a technology for forming spaces with high processing accuracy, the blast processing method described in Patent Document 1, which is a manufacturing method for a multi-row board with via holes (spaces) formed therein, is known. Patent Document 1 discloses a blast processing method in which a dry film with a mask pattern formed thereon is attached to both the front and back sides of the workpiece, and blast processing is performed from both the front and back sides of the workpiece.

Patent No. 6296407

In the blasting process described in Patent Document 1, the dry film must be attached precisely to both sides so that the mask pattern matches, and the workpiece must be turned over during processing, which can lengthen the processing time.

In view of the above, there is a need to provide a blast processing device and a blast processing method that can shorten the processing time.

One aspect of the present disclosure is a blast processing device. The blast processing device includes a nozzle unit, a storage unit, a supply unit, and a moving unit. The nozzle unit has multiple nozzles and a distribution mechanism. The multiple nozzles spray abrasive material onto the surface of the workpiece together with compressed air. The distribution mechanism distributes the abrasive material to the multiple nozzles. The storage unit stores the abrasive material therein. The supply unit supplies the abrasive material stored in the storage unit to the nozzle unit. The moving unit moves at least one of the multiple nozzles and the workpiece to change the relative positions of the multiple nozzles and the workpiece.

In this blast processing device, the abrasive is distributed to multiple nozzles by a distribution mechanism. The surface of the workpiece is sprayed with abrasive from each of the multiple nozzles. Because the multiple nozzles spray the abrasive onto the surface of the workpiece in parallel, this blast processing device can reduce processing time compared to blast processing devices that do not have multiple nozzles.

In one embodiment of the present disclosure, the distribution mechanism may have a dispersion member, an inlet pipe, and an outlet pipe. The dispersion member may define a dispersion chamber therein that disperses the abrasive in an aerosol state. The inlet pipe may connect the supply unit to the dispersion chamber, and supply the abrasive from the supply unit to the dispersion chamber. The outlet pipe may connect the multiple nozzles to the dispersion chamber, and supply the aerosol-like abrasive from the dispersion chamber to the multiple nozzles. This blast processing device can evenly supply the abrasive to the multiple nozzles because the abrasive is dispersed in an aerosol state in the dispersion chamber.

In one embodiment of the present disclosure, the dispersion member may be provided with an inlet communicating with the inlet pipe and an outlet communicating with the outlet pipe. The top surface of the dispersion chamber facing the inlet may be circular, and the outlet may be arranged in an annular shape surrounding the center of the top surface. This blast processing device can uniformly disperse aerosol-like abrasive from the center of the top surface toward the annularly arranged outlet.

In one embodiment of the present disclosure, the distance between the top surface and the inlet in a direction perpendicular to the top surface may be ⅕ or more and ½ or less of the diameter of the top surface. This blasting device can suppress uneven distribution of the aerosol-like abrasive in the dispersion chamber (i.e., uneven distribution of the amount of abrasive discharged from each outlet) by setting the distance between the top surface and the inlet, which is the height of the dispersion chamber, within a predetermined range.

In one embodiment of the present disclosure, the introduction pipe may be a circular pipe including a straight section connected to the dispersion member. The length of the straight section may be five times or more the inner diameter of the introduction pipe at the straight section. This blasting device can promote uniform dispersion of the aerosol-like abrasive because the flow of the abrasive by the compressed air is rectified in the straight section of the introduction pipe.

In one embodiment of the present disclosure, the blast processing device may further include a control unit that controls the operation of the moving unit. The control unit may control the moving unit to alternately perform a first scan and a second scan. In the first scan, the control unit may move at least one of the multiple nozzles and the workpiece along a first direction parallel to the surface of the workpiece. In the second scan, the control unit may move at least one of the multiple nozzles and the workpiece along a second direction perpendicular to the first direction and parallel to the surface of the workpiece. The movement distance in the second scan may be equal to or less than the diameter of the nozzles provided in the multiple nozzles. The multiple nozzles may be arranged side by side so as to be adjacent to each other in the second direction. By arranging the multiple nozzles in this way, the positions at which the abrasive is sprayed on the surface of the workpiece do not overlap, so that this blast processing device can efficiently blast the entire surface of the workpiece.

In one embodiment of the present disclosure, the blast processing device may further include a pressurizing conduit. The pressurizing conduit may supply compressed air to the storage section to pressurize the inside of the storage section and push the abrasive out to the supply section. This blast processing device can suppress pressure loss of the compressed air sprayed together with the abrasive by pressurizing and pushing out the abrasive from the storage section using the pressurizing conduit, thereby improving the processing capacity of the blast processing.

A blast processing method according to another aspect of the present disclosure includes the following steps (1) to (3).
(1) A process of preparing a printed circuit board material as a workpiece.
(2) A step of forming a resist layer having an opening of φ25 μm or more and φ80 μm or less on one surface of a printed circuit board material.
(3) A process of spraying an abrasive material onto one side of a printed circuit board material including a resist layer, and forming a through hole in the printed circuit board material through the opening in the resist layer, in which the ratio h/d of the depth h of the through hole to the diameter d of the opening in the resist layer is 0.8 or more and 2.0 or less.

This blasting method allows the formation of through holes with a high aspect ratio (h/d) by setting the openings in the resist layer within the above range.

In one embodiment of the present disclosure, the ratio Da/Db of the diameter Da of the through hole to the diameter Db of the opening in the resist layer may be 0.84 or more and 0.94 or less.

The technology disclosed herein can provide a blast processing device and a blast processing method that can shorten processing time.

1 is an overall cross-sectional view showing a blast processing device according to an embodiment. FIG. 3 is a perspective cross-sectional view of the distributor according to FIG. 2; FIG. FIG. 2 is a schematic diagram showing an arrangement state of nozzles. 10 is a schematic diagram showing a scanning trajectory caused by relative movement of the nozzle and the workpiece by the moving part. FIG. 1 is a flowchart of a blasting process.

Below, an embodiment of the present disclosure will be described with reference to the drawings. In the following description, the same or equivalent elements are given the same reference numerals, and redundant description will not be repeated. The dimensional ratios of the drawings do not necessarily match those in the description. The terms "upper", "lower", "left", and "right" are based on the state shown in the drawings unless otherwise specified, and are for convenience only. The X-axis direction, Y-axis direction, and Z-axis direction are mutually orthogonal axes in a Cartesian coordinate system in three-dimensional space.

(Blast processing equipment)
FIG. 1 is an overall cross-sectional view showing a blast processing device according to an embodiment. The blast processing device 1 is a device that sprays a fixed amount of abrasive 3 supplied by a supply unit 2. The blast processing device 1 sprays the abrasive 3 onto the surface of a workpiece 4 to perform blast processing, which is one of cutting processing methods such as cutting, groove processing, and hole processing. The abrasive 3 is, for example, alumina powder, pig iron grit, mold grit, etc. Examples of the workpiece 4 include hard and brittle materials such as ceramic materials and glass materials, difficult-to-cut materials such as CFRP (Carbon Fiber Reinforced Plastics) materials, and printed circuit board materials. The printed circuit board material is a base material in which a conductive thin film is formed on an insulating material or a glass epoxy board.

The blast processing device 1 includes a supply unit 2, a processing unit 5, a sorting unit 6, a dust collection unit 7, and a control unit 9. The blast processing device 1 sprays the abrasive 3 supplied through the supply unit 2 toward the surface of the workpiece 4 as a solid-gas two-phase flow together with compressed air in the processing unit 5 to perform blast processing. The blast processing device 1 recovers and reuses the sprayed abrasive 3 in the processing unit 5. When the workpiece 4 is blasted in the processing unit 5, powder 8 containing the used abrasive 3 is generated. The powder 8 includes, for example, reusable abrasive 3, abrasive 3 that has become unreusable due to crushing or wear, and cutting powder of the workpiece 4. The blast processing device 1 transfers the powder 8 from the processing unit 5 to the sorting unit 6. The blast processing device 1 transfers the reusable abrasive 3 from the sorting unit 6 to the supply unit 2 and sprays it. The blasting device 1 sends non-reusable abrasives 3 and cutting dust from the sorting section 6 to the dust collection section 7, where they are accumulated.

(Supply Department)
1 includes a storage section 10, a filling section 20, a roller 30, a drive section 40, and an unloading section 50. The storage section 10 stores an abrasive 3 therein. A pressurizing conduit 73 for supplying compressed air is connected to the storage section 10, and the inside of the storage section 10 is pressurized by the compressed air.

The filling section 20 is connected to the lower part of the storage section 10. A housing that houses the roller 30, the drive section 40, and part of the removal section 50 is connected to the lower part of the filling section 20. The roller 30 is cylindrical, and a rotating shaft (not shown) is connected to the center of both circular sides. In addition, multiple grooves are formed at equal intervals on the surface of the roller 30 in a direction parallel to the rotating shaft. The drive section 40 is a mechanism for rotating the roller 30 around the rotating shaft. The removal section 50 is a flow path for compressed air that is formed to cover part of the groove of the roller 30. A pipe (not shown) that supplies compressed air is connected to the removal section 50.

The abrasive 3 stored in the storage section 10 is transferred to the filling section 20. The abrasive 3 is then filled into the grooves of the roller 30 by the pressing force of the compressed air. The roller 30 rotates due to the operation of the drive section 40, so that the abrasive 3 is continuously filled into all of the grooves. The abrasive 3 that reaches the removal section 50 from the filling section 20 by the rotation of the roller 30 is pushed out of the grooves into the nozzle unit U by the compressed air. The abrasive 3 is then supplied to the nozzle 502 via the nozzle unit U.

(Processing department)
The processing section 5 performs blast processing on the workpiece 4. The processing section 5 has a case 501, a nozzle unit U, a processing table 503, and a moving section M. A processing chamber 509 is defined inside the case 501.

The nozzle unit U has a distribution mechanism 550 and a plurality of nozzles 502. The plurality of nozzles 502 are arranged, for example, at the upper part of the processing chamber 509. The plurality of nozzles 502 extend along the Z axis perpendicular to the surface of the workpiece 4, and each nozzle outlet faces the surface of the workpiece 4. The plurality of nozzles 502 inject the abrasive 3 together with compressed air onto the surface of the workpiece 4. The plurality of nozzles 502 inject the abrasive 3 as a mixed fluid (solid-gas two-phase flow) with the compressed air from each nozzle. The nozzles of each of the plurality of nozzles 502 are circular. The plurality of nozzles 502 are arranged side by side along the X axis (see FIG. 4). The negative direction of the X axis is the feed direction described later.

2 and 3, the distribution mechanism 550 has an inlet pipe 551, a dispersion member 552, and a plurality of outlet pipes 553. A dispersion chamber 552S is defined inside the dispersion member 552. One end of the inlet pipe 551 is connected to the supply unit 2, and the other end is connected to the dispersion chamber 552S. The dispersion member 552 is provided with an inlet port 551H that communicates with the inlet pipe 551. The number of the outlet pipes 553 is the same as the number of the nozzles 502. One end of each of the outlet pipes 553 is connected to one of the nozzles 502, and the other end is connected to the dispersion chamber 552S. The dispersion member 552 is provided with an outlet port 553H corresponding to each of the outlet pipes 553.

The abrasive 3 is pushed out from the take-out section 50 into the introduction pipe 551 of the nozzle unit U by the airflow of compressed air. The airflow containing the abrasive 3 pushed out into the introduction pipe 551 passes through the introduction pipe 551 and is supplied to the dispersion chamber 552S. The introduction pipe 551 may include a straight section 551S connected to the dispersion chamber 552S. By making the straight section 551S a straight circular pipe of a predetermined length, the airflow containing the abrasive 3 is rectified before being supplied to the dispersion chamber 552S. That is, the dispersion of the abrasive 3 is promoted in the airflow containing the abrasive 3. For example, the pipe length along the vertical direction (Z-axis direction) of the straight section 551S may be 5 times or more, preferably 10 times or more, the inner diameter of the introduction pipe 551 at the straight section 551S. By appropriately setting the length of the straight section 551S, the abrasive 3 can be efficiently dispersed.

The dispersion chamber 552S disperses the abrasive 3 supplied from the inlet pipe 551 so that it is uniform. The dispersion chamber 552S disperses the abrasive 3 in an aerosol form. The top surface 552A of the dispersion chamber 552S facing the inlet 551H is circular. Here, the distance (height H) between the inlet 551H and the top surface 552A may impair the uniformity of the aerosol concentration or impair the pressure when the abrasive 3 is sprayed from the multiple nozzles 502. The height H may be set to 1/5 to 1/2 of the diameter D1 of the top surface so as to maintain the uniformity of the aerosol concentration and not affect the spray pressure of the abrasive 3 from the multiple nozzles 502.

The multiple outlets 553H are arranged in a circular ring shape surrounding the center of the top surface 552A of the dispersion member 552. The abrasive 3 supplied from the inlet 551H strikes the circular top surface 552A opposite the inlet 551H and disperses in an aerosol state. The abrasive 3 in the aerosol state disperses uniformly from the center to the outer edge of the circular top surface 552A. The abrasive 3 dispersed in an aerosol state is pressed from the multiple outlets 553H through hoses to the multiple nozzles 502, respectively, and sprayed by the multiple nozzles 502. The multiple outlets 553H can be arranged so that the abrasive 3 is pressed evenly to each of the multiple nozzles 502. As an example, the outlet pipes 553 are arranged concentrically at equal intervals near the outer edge of the top surface 552A.

The moving unit M is a drive unit that changes the relative position between the workpiece 4 and the multiple nozzles 502. The moving unit M may move the workpiece 4, may move the multiple nozzles 502, or may move both the workpiece 4 and the multiple nozzles 502. In this embodiment, a configuration is described in which the moving unit M has a nozzle drive unit 504 and a workpiece drive unit 505, and both the multiple nozzles 502 and the workpiece 4 are moved.

The processing table 503 is a table on which the workpiece 4 is placed. The processing table 503 is arranged in the processing chamber 509. As shown in FIG. 4, the processing table 503 is placed on the workpiece drive unit 505 so that the surface on which the workpiece 4 is placed is perpendicular to the extension direction (Z-axis direction) of the multiple nozzles 502 in the spraying direction of the abrasive 3 from the multiple nozzles 502. The surface of the processing table 503 on which the workpiece 4 is placed may be a surface that adsorbs the workpiece 4.

The nozzle driving unit 504 is disposed on the upper part of the case 501. The nozzle driving unit 504 is connected to the multiple nozzles 502. The nozzle driving unit 504 moves the multiple nozzles 502 so that the area where the abrasive 3 is sprayed by the multiple nozzles 502 and the workpiece 4 move relative to each other. The workpiece driving unit 505 is disposed on the lower part of the case 501. The workpiece driving unit 505 is connected to the lower surface of the processing table 503. The workpiece driving unit 505 moves the processing table 503 on which the workpiece 4 is placed so that the area where the abrasive 3 is sprayed by the multiple nozzles 502 and the workpiece 4 move relative to each other. The workpiece driving unit 505 is a driving mechanism such as an XY stage. The trajectory (scanning trajectory) caused by the relative movement of the nozzle driving unit 504 and the workpiece driving unit 505 is controlled by the control unit 9.

The control unit 9 controls the operation of the moving unit M. The control unit 9 is composed of a general-purpose computer having, for example, an arithmetic unit such as a CPU (Central Processing Unit), a storage unit such as a ROM (Read Only Memory), a RAM (Random Access Memory) and a HDD (Hard Disk Drive), and a communication unit. The control unit 9 may be, for example, a motion controller such as a PLC (Programmable Logic Controller) or a DSP (Digital Signal Processor). The control unit 9 may be hardware that controls the entire blast processing device 1.

5 is a schematic diagram showing a trajectory (scanning trajectory) in a direction parallel to the surface of the workpiece 4 due to the relative movement of the workpiece 4 and the multiple nozzles 502. The scanning trajectory shows a zigzag shape along the X-axis direction and the Y-axis direction perpendicular to the X-axis direction. The control unit 9 controls the operation of the moving unit M so that the workpiece 4 and the multiple nozzles 502 draw such a scanning trajectory. A description will be given based on the scanning trajectory in the same figure. First, the relative positions of the workpiece 4 and the multiple nozzles 502 are adjusted so that the injection area of the nozzle 502A arranged in the most positive direction of the X-axis among the multiple nozzles 502 overlaps with the starting point S on the scanning trajectory. The starting point S is provided at the position in the most positive direction of the X-axis and the most negative direction of the Y-axis on the scanning trajectory. In this case, the other nozzles are arranged so as to be connected in the negative direction of the X-axis, so that the injection area of the other nozzles overlaps with another starting point (not shown) arranged in the negative direction of the X-axis as viewed from the starting point S. In the following, the ejection area of nozzle 502A will be described as the "ejection area."

First, the control unit 9 controls the operation of the workpiece drive unit 505 so that the injection area moves from the starting point S along the Y-axis direction (first direction) parallel to the surface of the workpiece 4 (first scan). Specifically, the workpiece 4 is moved along the negative direction of the Y-axis. Next, when the injection area reaches the end in the negative direction of the Y-axis, the control unit 9 controls the operation of the nozzle drive unit 504 so that the injection area moves along the X-axis direction (second direction) perpendicular to the Y-axis direction and parallel to the surface of the workpiece 4 (second scan). Specifically, the multiple nozzles 502 are moved along the negative direction of the X-axis (also referred to as the feed direction in this specification). Next, the control unit 9 controls the operation of the workpiece drive unit 505 so that the injection area moves along the Y-axis direction. Specifically, the workpiece 4 is moved along the positive direction of the Y-axis. When the injection area reaches the upper end in the first direction, the control unit 9 controls the operation of the nozzle drive unit 504 so that the injection area moves along the feed direction. By repeating this operation alternately, a scanning trajectory is drawn. Here, the gas-solid two-phase flow ejected from nozzle 502A has a velocity distribution, and the polishing force differs depending on the position from nozzle 502A. The movement distance in the feed direction is set taking into consideration this difference in polishing force. The movement distance in the feed direction may be, for example, not including 0 and may be equal to or less than the diameter of the ejection port of nozzle 502A.

(Sorting Department)
The sorting section 6 collects powder 8 generated during the blasting process of the workpiece 4 in the processing section 5. The sorting section 6 sends reusable abrasives 3 from the powder 8 to a storage section 10 described later. The sorting section 6 sends non-reusable abrasives 3, cutting powder generated by peeling off the workpiece 4, and the like from the powder 8 to a dust collector 702 described later. The sorting section 6 has a recovery pipe 601 and a classification section 602. The recovery pipe 601 is a pipe connected at one end to the processing section 5 and connected at the other end to the classification section 602. The recovery pipe 601 sends the powder 8 from the processing section 5 to the classification section 602 of the sorting section 6 on the airflow generated by the dust collector 702 described later.

The upper part of the classification section 602 is connected to the dust collection duct 701 described below. The lower part of the classification section 602 is connected to the storage section 10. The classification section 602 is, for example, a hollow structure shaped like a mortar. The classification section 602 classifies the powder 8 sent from the recovery duct 601 into reusable abrasive 3, non-reusable abrasive 3 and cutting powder. The classification section 602 is, for example, a cyclone.

The powder 8 rotates, for example, in the classification section 602. Among the powder 8, the reusable abrasive 3 is heavier than the non-reusable abrasive 3 and cutting powder. The reusable abrasive 3, which is a relatively heavy particle, falls and accumulates at the bottom of the classification section 602 due to gravity when the rotation speed slows down. When compressed air does not flow into the inside of the storage section 10, the valve between the classification section 602 and the storage section 10 is opened, and the storage section 10 and the classification section 602 are connected, the reusable abrasive 3 accumulated at the bottom of the classification section 602 is sent to the storage section 10 of the supply section 2. The non-reusable abrasive 3 and cutting powder, which are relatively light particles, are sent to the dust collection duct 701, which will be described later, connected to the top of the classification section 602.

(Dust collection section)
The dust collection section 7 accumulates the non-reusable abrasive 3 and cutting powder recovered in the sorting section 6. The dust collection section 7 has a dust collection conduit 701 and a dust collector 702. The dust collection conduit 701 is a tube connected at one end to the classification section 602 and connected at the other end to the dust collector 702. The dust collection conduit 701 sends the non-reusable abrasive 3 and cutting powder from the classification section 602 to the dust collector 702.

The dust collector 702 collects the non-reusable abrasive 3 and cutting powder sent from the dust collection duct 701. The dust collector 702 has a suction source and a filter (not shown). By operating the suction source, an airflow is generated toward the dust collector 702 in the processing chamber 509, the recovery duct 601, the classification section 602, and the dust collection duct 701, which are connected to the dust collector 702. By operating the suction source, the non-reusable abrasive 3 and cutting powder sent from the dust collection duct 701 are sucked into the dust collector 702 together with air. In the dust collector 702, a filter is arranged in the path between the dust collection duct 701 and the suction source. The filter collects the non-reusable abrasive 3 and cutting powder. Only air is transferred to the suction source by the filter. The collected non-reusable abrasive 3 and cutting dust can be recovered by removing the filter.

(Blast processing equipment process)
The blasting process using the blasting device 1 will be described. Here, the blasting process for forming through holes for forming via holes and through holes will be described as an example using a printed circuit board material as the workpiece 4. The printed circuit board is produced by attaching a conductor foil such as copper to the surface of an insulating sheet such as polyimide or polyester and a glass epoxy board. Fig. 6 is a flowchart showing the entire process of the blasting device 1 according to the embodiment.

First, a preparation step (step S1) of the workpiece 4 is performed. In step S1, a mask pattern is formed on the surface of the workpiece 4. Specifically, the workpiece 4 is heated, and a mask material is attached to the heated workpiece 4 (surface) by a laminator. Then, the workpiece 4 with the mask material attached is placed in an exposure machine. In the exposure machine, the position of the pattern master is aligned with the workpiece 4 using a CCD (Charge Coupled Device) camera and exposed. The exposed workpiece 4 is then placed in a developing machine. In the developing machine, the workpiece 4 is rotated while a developing solution is sprayed onto it, forming a mask pattern of a resist layer. Here, the resist layer is provided with openings of at least φ25 μm to φ80 μm that correspond to the holes to be processed.

Next, a preparation process (process S2) of the blast processing device 1 is performed. In process S2, the distance between the multiple nozzles 502 in the nozzle drive unit 504 and the workpiece 4, the spray pressure of the abrasive 3 from the multiple nozzles 502, etc. are adjusted. To adjust the spray pressure, first, compressed air is supplied to the multiple nozzles 502 via a hose. Next, the spray pressure of the abrasive 3 is adjusted to a predetermined pressure by operating a pressure valve. After the spray pressure has been adjusted, the supply of compressed air is stopped.

In step S2, the control unit 9 sets the operation pattern of the moving unit M. The operation pattern includes the scanning trajectories of the multiple nozzles 502, the moving speed, the number of scans, etc. Setting information indicating the operation pattern is stored in the storage device of the control unit 9.

After these adjustments are completed, the abrasive 3 is added to the storage section 10 of the supply section 2. The amount of abrasive 3 added corresponds to the amount of injection.

Then, a process for setting the workpiece 4 (S3) is performed. In process S3, the workpiece 4 is placed on the surface of the processing table 503 that faces the multiple nozzles 502 through an observation window provided in the processing chamber 509.

Next, the blasting process (S4) is performed. In process S4, first, compressed air is supplied to the storage section 10 through the pressurizing conduit 73. Next, the inside of the storage section 10 is pressurized by supplying compressed air to the inside of the storage section 10, and the valve between the storage section 10 and the classification section 602 is closed. This seals the storage section 10. Next, the abrasive 3 is pressurized in the storage section 10 by the compressed air and moves to the filling section 20. Next, the abrasive 3 is filled into the grooves of the roller 30 by the pressing force of the compressed air. The abrasive 3 is pressurized by compressed air through the storage section 10 and the filling section 20, so that it is densely filled in each groove. Next, the roller 30 is rotated by the power of the drive section 40 at a speed set by the control section 9. Next, the abrasive 3 filled in the grooves is moved to the position of the take-out section 50 by the rotation of the roller 30 in the rotation process (S21), and a flow path is formed. Next, compressed air is supplied from the duct to the flow path. The compressed air creates an airflow in a direction parallel to the extension direction of the groove. The airflow created by the compressed air pushes the abrasive material 3 filled in the groove to the nozzle unit U.

The abrasive 3 pushed out together with the compressed air into the nozzle unit U is directed toward the distribution mechanism 550 of the nozzle unit U. The abrasive 3 supplied to the inlet pipe 551 of the distribution mechanism 550 is rectified as it passes through the inlet pipe 551, and initial dispersion is performed. The abrasive 3 supplied to the dispersion member 552 is dispersed in an aerosol state in the dispersion chamber 552S. The dispersed abrasive 3 is pressed out of the discharge pipe 553 together with the compressed air.

The abrasive 3 pressed out from the outlet pipe 553 is supplied to the multiple nozzles 502 via a hose. The workpiece 4 is blasted by spraying the abrasive 3 together with compressed air as a mixed fluid from the multiple nozzles 502. Based on the scanning trajectory, scanning speed, number of scans, etc. set in the preparation step (S3), the workpiece drive unit 505 moves the workpiece 4 on the workpiece drive unit 505 and the processing table 503 relative to the multiple nozzles 502. The workpiece 4 is processed based on the scanning trajectory set in the control unit 9. Here, since the multiple nozzles 502 are arranged in a row so as to be connected along the X-axis direction, the number of scans can be set to be smaller than when one nozzle is arranged. In addition, the movement distance in the feed direction can be set shorter than when one nozzle is arranged or when multiple nozzles are arranged in a row so as to be connected along the Y-axis direction. In other words, the number of scans is reduced and the movement distance in the feed direction is shortened, thereby reducing excessive collision of the abrasive 3 with the resist layer. As a result, damage to the resist layer can be reduced. Therefore, cutting can be efficiently performed on the surface of the workpiece 4 exposed through the openings (holes) in the resist layer, allowing through holes to be formed with high precision. If the damage to the resist layer is significant, the openings in the resist layer will be damaged before the holes penetrate through. By performing blast processing using the blast processing device 1 of one embodiment, it is possible to form through holes with an aspect ratio (h/d, which is the ratio of the depth h of the through hole to the diameter d of the opening in the resist layer) of 0.8 to 2.0.

In the blast processing device 1 of one embodiment, the nozzles 502 have circular injection ports, and the intervals at which the nozzles 502 are arranged are adjusted to obtain an injection flow that has a small variation in the velocity distribution as a whole and can perform a wide range of processing. If the nozzle injection ports are rectangular so as to obtain an injection flow with the same processing width as the blast processing device 1 of one embodiment, the velocity distribution of the injection flow has a large variation. As a result, in a blast processing device with a large variation in the velocity distribution of the injection flow compared to the blast processing device 1 of one embodiment, it is necessary to increase the number of scans or shorten the moving distance in the feed direction. Therefore, the blast processing device 1 of one embodiment can perform blast processing with higher accuracy. By processing with the blast processing device 1 of one embodiment, holes can be formed in which the ratio Da/Db, which is the diameter Da of the through hole formed on the surface of the workpiece 4 to the diameter Db of the opening formed in the resist layer, is 0.84 to 0.94.

When the set scanning and processing is completed, the abrasive 3 and compressed air sprayed from the multiple nozzles 502 are stopped.

In addition, in the blast processing step (S4), a dust collection step is also performed. In the dust collection step, the dust collector 702 generates an airflow in the processing chamber 509, the recovery conduit 601, the classification section 602, and the dust collection conduit 701, in which the powder 8 and air are sucked toward the dust collector 702. The airflow generated by the operation of the dust collector 702 moves the powder 8 generated in the processing chamber 509 in the order of the processing chamber 509, the recovery conduit 601, and the classification section 602. By classification in the classification section 602, the reusable abrasive 3 is collected in the storage section 10, and the non-reusable abrasive 3 and cutting dust are collected in the dust collector 702 through the dust collection conduit 701.

Finally, the workpiece recovery step (S5) is performed. In step S5, the workpiece 4 is recovered from the surface of the processing table 503 through the observation window of the case 501.

Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-mentioned embodiments. Appropriate modifications can be made without changing the gist of the invention. Furthermore, the above-mentioned embodiments can be combined without causing any contradictions.

(Effects of the embodiment)
As described above, according to the blast processing device 1 of this embodiment, a wide injection area can be obtained by arranging the multiple nozzles 502 in a line so as to be connected along the feed direction of the scanning trajectory. By providing the distribution mechanism 550, the abrasive 3 can be evenly supplied to the multiple nozzles 502, so that all the multiple nozzles 502 can have the same processing capacity. As a result, in the area where it collides with the workpiece 4, it is possible to obtain an injection flow with a small velocity distribution (i.e., an injection area with small variation in processing capacity).

Since the blast processing device 1 is equipped with multiple nozzles 502, the time during which the abrasive 3 is sprayed onto the workpiece 4 can be shortened. Therefore, it is possible to achieve both a shortened processing time and a reduction in damage to the workpiece 4. In addition, since it is equipped with a distribution mechanism 550 that can evenly distribute the abrasive 3 supplied from a single storage section 10 to the multiple nozzles 502, the overall processing accuracy is improved.

The distribution mechanism 550 is configured such that the introduction pipe 551, the dispersion member 552, and the discharge pipe 553 are connected in this order, and thus it is possible to provide all the nozzles with approximately the same processing capacity with a simple structure. By making the top surface 552A of the dispersion chamber 552S of the dispersion member 552 circular and arranging the discharge pipe in a ring shape so as to surround the center of the top surface 552A, the abrasive 3 dispersed in an aerosol state of uniform concentration in the dispersion chamber 552S can be supplied to all the multiple nozzles 502. By making the height of the dispersion chamber 552S 1/5 to 1/2 of the diameter of the top surface 552A, an excellent dispersion effect can be obtained. In addition, by making the straight portion 551S connected to the dispersion chamber 552S of the introduction pipe 551 a circular pipe whose pipe length is 5 times or more the inner diameter, the abrasive 3 can be introduced into the dispersion member 552 in an initially dispersed state.

Because a jet flow with a narrow velocity distribution can be obtained, the number of times the workpiece 4 needs to be moved relative to the multiple nozzles 502 to trace a scanning trajectory can be reduced, and the movement distance in the feed direction (not including 0 and equal to or less than the diameter of the jet nozzles of the multiple nozzles 502) can be increased. As a result, excessive collision of the abrasive 3 with the workpiece 4 can be reduced, thereby reducing damage to the workpiece 4.

By pressurizing the storage section 10 and pushing the abrasive 3 through the supply section 2 into the introduction pipe 551 toward the distribution mechanism 550, the pressure loss of the compressed air can be reduced. As a result, the processing capacity can be improved, and the number of times the workpiece 4 is moved relative to the nozzle to trace a scanning trajectory can be reduced. In addition, since the processing capacity of the abrasive 3 is high, the time that the abrasive 3 is in contact with the workpiece 4 can be shortened, so that both a reduction in processing time and a reduction in damage to the workpiece 4 can be achieved.

The multiple nozzles 502 are arranged side by side so as to be connected along the X-axis direction. By arranging the multiple nozzles 502 in this manner, it is possible to achieve both a reduction in processing time and a reduction in damage to the workpiece 4.

The blast processing device 1 can achieve both shortening of processing time and reduction of damage to the workpiece 4. When performing hole processing or groove processing, a resist layer is provided on the workpiece 4, and the blast processing device 1 can reduce damage to this resist layer. For example, when performing blast processing to open through holes such as through holes and via holes in a printed circuit board material, which is an example of the workpiece 4, damage to the resist layer can be reduced, so that blast processing with high accuracy can be performed. That is, by performing blast processing using the blast processing device 1 according to this embodiment, even if a resist pattern with an extremely small diameter of an opening of φ25 to φ80 μm or less is formed, processing with an aspect ratio (h/d) of 0.8 to 2.0 or less, which is difficult to achieve with normal blast processing, is possible. In addition, processing with an accuracy difficult to achieve with normal blast processing is possible, with Da/Db being the ratio of the diameter Da of the through hole formed in the workpiece 4 to the diameter Db of the opening formed in the resist layer, being 0.84 to 0.94 or less.

According to the blasting device 1 and blasting method of this embodiment, the above-mentioned high-precision processing can be performed by spraying the abrasive material 3 only from one side. In addition, the verticality of the space can be improved. In particular, it is suitable for forming holes for forming via holes or through holes, which are very fine holes.

(Modification)
The dispersion member 552 in the embodiment may be not only cylindrical but also conical or truncated conical. These shapes have a continuously expanding diameter from the introduction portion toward the bottom surface, so that the abrasive 3 can be dispersed to form an aerosol with a more uniform concentration.

1...blasting device, 2...supply section, 3...abrasive, 4...workpiece, 5...processing section, 6...sorting section, 7...dust collection section, 8...powder, 9...control section, 10...storage section, 20...filling section, 30...roller, 40...drive section, 50...removal section, 73...pressurizing conduit, 501...case, 502...nozzle, 503...processing table, 504...nozzle drive section, 505...workpiece drive section, 509...processing chamber, 550...distribution mechanism, 551...inlet pipe, 551S...straight section, 552...dispersion member, 552A...top surface, 553...outlet pipe, 601...recovery conduit, 602...classification section, 701...dust collection conduit, 702...dust collector, U...nozzle unit, M...moving section.

Claims (5)

a nozzle unit having a plurality of nozzles for injecting an abrasive material together with compressed air onto a surface of a workpiece, and a distribution mechanism for distributing the abrasive material to the plurality of nozzles;
A storage section for storing the abrasive therein;
a supply section that supplies the abrasive stored in the storage section to the nozzle unit;
a moving unit that moves at least one of the plurality of nozzles and the workpiece to change a relative position between the plurality of nozzles and the workpiece;
Equipped with
The distribution mechanism includes:
A dispersion member defining a dispersion chamber therein for dispersing the abrasive in an aerosol state;
an introduction pipe that connects the supply unit and the dispersion chamber and supplies the abrasive from the supply unit to the dispersion chamber;
an outlet pipe connecting the plurality of nozzles and the dispersion chamber and supplying the aerosol-like abrasive in the dispersion chamber to the plurality of nozzles;
Including,
The dispersion member is provided with an inlet communicating with the inlet pipe and an outlet communicating with the outlet pipe,
The top surface of the dispersion chamber facing the inlet is circular,
The outlet pipe is disposed near an outer edge of the top surface,
The outlet is disposed in a circular ring shape so as to surround the center of the top surface,
a distance between the top surface and the inlet in a direction perpendicular to the top surface is equal to or greater than ⅕ and equal to or less than ½ of a diameter of the top surface;
the inlet pipe is a circular pipe including a straight portion connected to the dispersion member,
The length of the straight portion is 5 times or more the inner diameter of the introduction pipe at the straight portion.
Blasting equipment. A control unit for controlling the operation of the moving unit is further provided.
The control unit is
a first scan in which at least one of the plurality of nozzles and the workpiece is moved along a first direction parallel to a surface of the workpiece;
a second scan in which at least one of the nozzles and the workpiece is moved along a second direction perpendicular to the first direction and parallel to a surface of the workpiece;
and controlling the moving unit so as to alternately carry out the steps.
a moving distance in the second scan is equal to or less than a diameter of an ejection port provided in the plurality of nozzles,
The blast processing device according to claim 1 , wherein the plurality of nozzles are arranged side by side so as to be adjacent to each other in the second direction. a pressurizing conduit for supplying compressed air to the storage section to pressurize the inside of the storage section and push the abrasive material to the nozzle unit;
The blast processing device according to claim 1 or 2 . preparing a printed circuit board material as the workpiece;
forming a resist layer having an opening having a diameter of 25 μm or more and 80 μm or less on one surface of the printed circuit board material;
a step of spraying the abrasive material onto the one surface of the printed circuit board material including the resist layer, and forming a through hole in the printed circuit board material through an opening in the resist layer;
Equipped with
The blast processing method using the blast processing device according to any one of claims 1 to 3, wherein a ratio h/d of a depth h of the through hole to a diameter d of an opening in the resist layer is 0.8 or more and 2.0 or less. The blasting method according to claim 4, wherein the ratio Da/Db of the diameter Da of the through hole to the diameter Db of the opening in the resist layer is 0.84 or more and 0.94 or less.

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