JP4637705B2 - Thin substrate cleaning method and apparatus - Google Patents

Description

  The present invention relates to a method and an apparatus for cleaning a thin substrate such as a printed wiring board and a printed board. The printed wiring board to which the present invention is directed is a board in which a conductive layer is formed in a wiring pattern on an insulating substrate, and the printed board is an electronic component assembled on a printed wiring board. The printed wiring board includes a rigid wiring board represented by a glass epoxy copper-clad laminate and a flexible wiring board represented by a polyimide copper-clad wiring board.

  In the present specification and claims, the “thin substrate” refers to a thin plate provided with a printed circuit before or after mounting an electronic component, such as the printed wiring board, the printed board, and the flexible board.

  For example, a thin substrate such as a printed wiring board for an interposer is washed to remove flux, solder balls, and the like attached to the surface after undergoing a solder bump forming process and a reflow process. However, in many cases, solder bumps are formed on both sides of such a thin substrate. In that case, it is necessary to avoid the use of contact-type equipment for cleaning and transportation so as not to cause deformation or dropout of the solder bumps. Even in the case of a substrate on which solder bumps are not formed, a conductive thin film formed by gold plating or the like is formed on the surface, so that the use of a contact-type cleaning tool or a transport device can be avoided so as not to damage the thin film.

  Therefore, conventionally, a method has been adopted in which the edge of a thin substrate is supported by a support portion and cleaning is performed by spraying a cleaning liquid onto the substrate surface. At that time, in the case of a typical thin plate substrate, the thickness is as thin as 0.3 to 3 mm (the plane dimension is 240 mm × 110 to 330 mm). However, there was a problem of falling off the support part.

  As one method for dealing with this, cleaning has been performed as follows. That is, as shown in FIG. 10A, the opposite edges of the substrate W are sandwiched from above and below by the pinch rollers 101 and 102, the substrate is held horizontally, and the substrate is conveyed while being held by the rotation of the pinch roller. Then, the cleaning liquid is sprayed to the upper surface of the substrate from a large number of spray nozzles 103 arranged orthogonally to the transport direction above the substrate, and from the large number of spray nozzles 104 arranged corresponding to the spray nozzle 103 below the substrate to the bottom surface of the substrate. Spray liquid. Thus, the substrate W is prevented from being bent by the injection from the upper and lower injection nozzles.

  However, while the jets from both the upper and lower sides act to push the substrates against each other, it is extremely difficult to accurately control the jets from a number of jet nozzles. As a result, even if the pressing force from both the upper and lower sides is made the same, fluctuation cannot be avoided and the substrate vibrates up and down. Further, pinching by the pinch roller cannot withstand the difference in pressing force from both the upper and lower sides. Further, the thin substrate is easily bent downward due to the weight of the cleaning liquid accumulated on the thin substrate being applied to the upward spray pressure. As a result, it has not been possible to solve the problem that the conveyance of the substrate becomes unstable or falls off the pinch roller during the conveyance.

  In addition to the above printed wiring boards for interposers, general printed circuit boards, printed wiring boards, etc. also have cleaning technology unique to thin substrates from the viewpoint of removing flux and solder balls, preventing damage to solder bumps and conductive thin films, etc. Although necessary, the same problems as described above were caused, and appropriate measures were not taken. In particular, the reduction in thickness of the substrate is in progress (for example, from the above typical dimension to a thickness of about 0.1 mm). With this, the above problem has become serious, and the solution is awaited. .

  Accordingly, an object of the present invention is to provide a thin substrate cleaning method and a cleaning apparatus capable of performing cleaning without causing a problem of substrate dropping due to bending.

  In order to achieve the above-mentioned object, the present invention holds the substrate by supporting opposing edges of the thin substrate such as a thin printed substrate or a printed wiring board, and sprays the cleaning liquid on the upper surface of the substrate to clean the upper surface. A method for cleaning a thin substrate, characterized in that the substrate is supported from below by continuously overflowing liquid from a discharge port that opens along the bottom surface of the substrate, and the substrate is supported from below. (First invention).

  In order to achieve the above object, the present invention also holds a substrate by supporting opposite edges of a thin substrate such as a thin printed circuit board or a printed wiring board with a pair of supporting portions, and applies a cleaning liquid to the upper surface of the substrate. A cleaning method for cleaning the upper surface by spraying, wherein the substrate is held at least in a non-cleaned state by supporting the substrate by sandwiching the substrate from above and below by raising the opposite sides of the pair of support portions and lowering the outside. A thin substrate cleaning method is provided, wherein the substrate is held in a convex shape (second invention).

  Further, in order to achieve the above object, the present invention holds a substrate by supporting opposite edges of a thin substrate such as a thin printed circuit board or a printed wiring board with a pair of supporting portions, and applies a cleaning liquid to the upper surface of the substrate. A cleaning method for cleaning the upper surface by spraying, wherein the substrate is held at least in a non-cleaned state by supporting the substrate by sandwiching the substrate from above and below by raising the opposite sides of the pair of support portions and lowering the outside. The thin substrate is cleaned while the substrate is supported from below by holding the substrate in a convex shape and continuously overflowing the liquid from the outlet opening along the lower surface of the substrate. A method is provided (third invention).

  In order to achieve the above-mentioned object, the present invention further includes: a supporting portion that holds a substrate by supporting opposing edges in a thin substrate such as a thin printed circuit board and a printed wiring board; A spraying device that sprays cleaning liquid on the upper surface, and a liquid supply device that includes a discharge port that opens along the lower surface of the substrate and supports the substrate from below by continuing to overflow the liquid from the discharge port. A thin substrate cleaning apparatus is provided (fourth invention).

  In order to achieve the above-mentioned object, the present invention further includes a supporting portion for holding a substrate by supporting opposite edges of a thin substrate such as a thin printed substrate or a printed wiring board by a pair of supporting portions, and an upper surface of the substrate. A spraying device for spraying a cleaning liquid on the upper surface so as to perform cleaning, and the support portion is configured such that the opposing sides of the pair of support portions are raised so as to hold the substrate in a convex shape at least in a non-cleaning state. The present invention provides a thin substrate cleaning apparatus characterized in that the outside is lowered and the substrate is sandwiched from above and below (fifth invention).

  In order to achieve the above-mentioned object, the present invention further includes a supporting portion for holding a substrate by supporting opposite edges of a thin substrate such as a thin printed substrate or a printed wiring board by a pair of supporting portions, and an upper surface of the substrate. A spraying device that sprays cleaning liquid onto the upper surface so as to clean, and a liquid supply device that includes a discharge port that opens along the bottom surface of the substrate and supports the substrate from below by continuing to overflow the liquid from the discharge port, The support portion has a shape that sandwiches the substrate from above and below by raising the facing side of the pair of support portions and lowering the outside so as to hold the substrate in a convex shape at least in a non-cleaned state. Accordingly, the present invention provides a thin substrate cleaning apparatus characterized in that (6th invention).

  According to the first aspect of the present invention, the substrate is held by supporting the opposing edges in the thin substrate such as a thin printed circuit board and a printed wiring board, and the upper surface is cleaned by spraying a cleaning liquid on the upper surface of the substrate. Cleaning can be performed without bringing a contact-type cleaning tool such as a brush into contact with the upper surface of the substrate. In particular, in the first aspect of the invention, the cleaning is performed while the substrate is supported from below by continuously overflowing the liquid from the outlet opening along the lower surface of the substrate. This overflow flow exerts a force that attracts the lower surface of the substrate toward itself and exerts an upward force associated with the overflow. Therefore, by maintaining this overflow flow, the substrate is stabilized at the balance position with respect to forces in both the upper and lower directions. As a result, even if the spraying force of the cleaning liquid acts on the upper surface of the substrate, the influence of this can be reduced and the substrate can be held in a stable position. Therefore, the bending of the substrate at the time of cleaning can be suppressed so as not to cause the problem of the substrate falling off.

  The overflow of the liquid is in a form in which the flow of the liquid discharged from the discharge port opened upward flows out to at least a part around the discharge port without leaving the edge of the discharge port. Further, it is desirable that this overflow flows out uniformly in a wide range from the discharge port, and it is most desirable to flow out uniformly in all directions. As a form for this purpose, the discharge port is preferably a shape having a smooth curved edge such as an ellipse or an oval, and is most preferably a circle. Alternatively, as long as the above homogeneity is maintained, it may be a square shape such as a quadrangle, hexagon, triangle, etc. In this case, it is more preferable to use an isotropic shape such as a regular polygon. desirable.

  According to the second aspect of the invention, by supporting the opposing edges of the thin substrate such as a thin printed circuit board and a printed wiring board, the substrate is held, and the upper surface is cleaned by spraying a cleaning liquid on the upper surface of the substrate. As in the first invention, cleaning can be performed without bringing the cleaning tool into contact with the upper surface of the substrate. In particular, in the second aspect of the invention, the substrate is held in a convex shape at least in the non-cleaned state by sandwiching and supporting the substrate edge from above and below so that the inside of the substrate edge is higher than the outside. This upwardly convex shape has the property that it does not easily cause downward deformation even when a force is applied from above. Therefore, even if the cleaning liquid spray force acts on the upper surface of the substrate, the substrate strongly resists downward deformation and maintains the upward convex shape. The deformation region and the degree of deformation are limited. As a result, it is possible to suppress the bending of the substrate during cleaning so as not to cause the problem of the substrate falling off.

  The third invention has the characteristics of the first invention and the second invention. Therefore, the effects of both the inventions are combined to provide a more excellent substrate bending prevention effect.

  The fourth aspect of the invention is an apparatus for carrying out the method of the first aspect of the invention. For this purpose, as described above, the support part for supporting the edge of the substrate, the apparatus for spraying the cleaning liquid onto the upper surface of the substrate, and the overflow flow And a liquid supply device for supporting the substrate from below. Therefore, the bending of the substrate during cleaning can be suppressed as in the first invention.

  The fifth aspect of the invention is an apparatus for carrying out the method of the second aspect of the invention, and for this purpose, as described above, includes a support part that supports the edge of the substrate, and a cleaning liquid spraying device on the upper surface of the substrate. The support part holds the substrate from above and below and holds it in an upwardly convex shape. Therefore, the bending of the substrate during cleaning can be suppressed as in the second invention.

  The sixth invention has the characteristics of the fourth and fifth inventions. Therefore, the effects of both the inventions are combined to provide a more excellent substrate bending prevention effect.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the embodiments shown in the drawings, the same or similar members may be denoted by the same reference numerals and description thereof may be omitted.

  FIG. 1 shows a cleaning facility equipped with a printed circuit thin substrate cleaning apparatus according to an embodiment of the present invention, wherein (a) is a plan view and (b) is a front view. This cleaning equipment includes six stations S1 to S6, and the substrate W is transported from the right to the left in the figure. In each station, a chemical solution, a rinsing solution, water, or the like is used as a cleaning solution as necessary to remove dirt or rinse the chemical solution. The substrate W is placed on the guide rail G, stops at each station during the cleaning and rinsing processes, and is moved to the next station by a driving device (not shown).

  FIG. 2 is a schematic view of one cleaning station S centered on the cleaning apparatus 1. The cleaning device 1 includes a support unit 2 that supports the edge of the substrate W, a spraying device 3 that supplies cleaning liquid to the upper surface of the substrate W, and a liquid supply device that includes a discharge port that opens along the lower surface of the substrate W. 4 is provided. In this example, the cleaning device 1 includes a box-shaped liquid receiving portion 6 that is located on the lower side and that has an open upper end surface, and a lid portion 7 that is located on the upper side and that has an open lower end surface. The support portion 2, the spraying device 3, and the liquid supply device 4 are surrounded so that the cleaning liquid is not scattered. Each station including the cleaning device 1 includes a pump P for supplying cleaning liquid, and the pump is connected to the spraying device 3 of the cleaning device 1 via pipes K1 and K2. A tube K3 is connected to the bottom of the liquid receiving portion 6, and the tube K3 is inserted into the liquid storage tank R below the cleaning device. And the bottom part of the storage tank R is connected to the pump P through the pipe | tube K5. The pipe K1 branches at the boundary with the pipe K2 and extends to the pipe K4. The pipe K4 is connected to the liquid supply device 4. The pipes K2 and K4 are provided with control valves C2 and C4, automatic valves D2 and D4, and pressure gauges E2 and E4 (or flow meters F2 and F4), respectively. The control valves C2 and C4 are used to manually set the flow rate, and the automatic valves D2 and D4 adjust the timing of flowing the cleaning liquid to the spraying device 3 and the liquid supply device 4. A check valve G4 is provided near the cleaning device 1 of the pipe K4, and is used to hold the cleaning liquid in the liquid supply device 4 by closing it when the operation of the pump P is stopped. Further, the tube K5 is provided with a strainer H5 for removing impurities and the like.

  Accordingly, when the apparatus is operated, the cleaning liquid sent out from the pump P is sprayed from the spraying device 3 to the substrate W through the tubes K1 and K2, and overflows from the liquid supply device 4 through the tube K4. Are received by the liquid receiving portion 6, temporarily stored in the liquid storage tank R through the pipe K 3, and then returned to the pump P through the pipe 5.

  FIG. 3 shows details of the cleaning apparatus 1. The support portion 2 that holds the substrate W includes a support portion 21 constituted by the guide rail G, a pressing portion 22 that clamps opposing edges of the substrate in cooperation with the support portion, and presses the pressing portion from above. And a pressing portion 23 for releasing the same. The pressing portion 23 is coupled to the lid portion 7, and is moved up and down together with the lid portion 7 by a lifting device (not shown) connected to the lid portion, and when the lower portion is lowered, the pressing portion 22 is pushed down to place the substrate between the support portions 21. W is clamped and released when lifted.

  The spraying device 3 includes a rotary joint 31 coupled to the tip of the tube K2, a shaft portion 32 joined to the lower portion of the rotary joint 31, and a rotating nozzle coupled to the shaft portion and positioned above the substrate W. 33. The rotary nozzle 33 includes two arms 331 extending radially from the shaft portion 32 and four nozzle tips 332 attached to the tips of the arms. The nozzle tip 332 ejects the cleaning liquid radially, and the ejection center line is directed in the direction perpendicular to the arm and downward by 20 degrees with respect to the horizontal plane. The position of the spraying device 3 is fixed, and the spraying device 3 is loosely passed through a through hole provided in the top plate of the lid portion 7. The rotary nozzle 33 is connected to a rotary drive device (not shown) at the rotary joint 31 and rotates in the same direction as the injection direction as shown in FIG. 4 while ejecting the cleaning liquid from the nozzle tip 332. Thus, the cleaning liquid is sprayed uniformly on the upper surface of the substrate W in a vortex pattern.

  The liquid supply device 4 includes an upper bowl-shaped portion 41 and a connection portion 42 that extends downward from the bowl-shaped portion, and is connected to the tube K4 via the connection portion 42. The upper end of the bowl-shaped portion 41 is a discharge port 411 that opens horizontally along the lower surface of the substrate W. An O-ring 412 is disposed on the upper surface of the peripheral wall surrounding the discharge port 411. The liquid supply device 4 is set at a distance from the substrate W so that the overflow flow has the following action. The liquid supply device 4 may be fixed at such a position, or may be moved up and down by an unillustrated driving device for adjusting the distance. The O-ring is provided to prevent the substrate W from being damaged even if the substrate W comes into contact with the liquid supply device 4 in an unexpected situation. However, if this is not necessary, the O-ring can be omitted.

  In this embodiment, since only one liquid supply device 4 is provided, it is desirable to locate it at the center of the substrate. However, a plurality of liquid supply devices can be provided as necessary. In this case, each liquid supply apparatus is disposed so as to hold the substrate in a balanced manner. Thereby, it can respond to the board | substrate of a big dimension, or the flow volume of the liquid supply apparatus per piece can be reduced.

  Next, the support part 2 will be further described in detail. As shown in FIG. 5 and FIGS. 6A and 6B, the support portion 21 of the support portion 2 has a placement portion 211 on which the opposite edges of the substrate W are placed, and an upright standing up from the placement portion. Part 212. The holding part 22 is arranged along the support part 21, has a dimension slightly longer than the edge of the substrate to be sandwiched, and is supported so as to be slidable in the vertical direction with respect to the support part 21. The holding part 22 also has an outer part 221 disposed outside the pair of support parts 21, an inner part 223 located inside the upright part 212, and upper ends that connect the upper ends of the outer part 221 and the inner part 223. Part 222.

  The support portion 2 has a shape that sandwiches the substrate W from above and below by raising the facing sides of the pair of support portions and lowering the outside thereof. That is, in FIG. 6A, the mounting portion 211 of the support portion 21 is inclined so that the edge on the side where the pair of mounting portions 211 face each other is high and the opposite side is low. Further, in FIG. 6B, the edge on the side where the pair of mounting portions 211 face each other and the edge on the opposite side are high, and the cross section is a concave shape having an arc shape so that the middle part thereof is low. ing. As shown in FIGS. 6A and 6B, the lower end surface of the inner portion 223 of the holding portion 22 has a shape corresponding to each placement portion 211.

  In addition to the above, the support part 2 can also be formed so that the inclination of the placement part 211 in FIG. 6A is a concave curve instead of a straight section. Moreover, the concave shape of the mounting portion 211 in FIG. 6B can be linearly formed in a V-shaped or U-shaped cross section instead of an arc-shaped cross section. It is desirable that the lower end surface of the inner part 223 has a shape corresponding to the placement part 211 with respect to the placement part 211.

  When the mounting portion 211 is linearly inclined as shown in FIG. 6A, the inclination angle is preferably 3 to 10 degrees. If it is less than 3 degrees, the upper convex shape of the substrate W is not sufficiently formed. Further, if it exceeds 10 degrees, there arises a problem that the substrate W is plastically deformed or easily detached from the support portion 2. Further, when the mounting portion 211 is inclined by a concave curve, or has an arc shape or a V-shaped concave shape, the substrate W supported by the support portion 2 faces the edge of the mounting portion 211 (a pair of mounting portions face each other). It is desirable to set the inclination shown by the position of the side edge to be 3 to 10 degrees. When the angle is less than 3 degrees and exceeds 10 degrees, the same trouble as in FIG. 6A occurs.

  The dimensions of the apparatus according to this embodiment and the substrate used are exemplified below. In addition, the range of a desirable dimension in the implementation of the present invention is described in parentheses [].

Substrate: Width (dimension between support parts) 242 mm [10 to 600 mm], length 100 to 350 mm [10 to 800 mm], thickness 0.2 to 1.5 mm [0.1 to 2 mm]
The width of the mounting portion 211 of the support portion: 5 mm [3 to 15 mm]
Opening diameter of discharge port 411 of liquid supply apparatus: 50 mm [10 to 200 mm]
Distance from substrate W to discharge port 411 of liquid supply device: 10 mm [5 to 20 mm]
Next, a substrate cleaning method using the cleaning apparatus according to this embodiment will be described. There are the following three implementation methods.
(i) Cleaning method for supporting substrate with liquid supply device
(ii) Cleaning method for gripping the substrate by the support part
(iii) Cleaning method using both (i) and (ii) above First, the method (i) will be described. First, the substrate W is moved along the guide rail G and stopped at the station S1. In this method, the substrate W is held in a state of being placed on the placement portion 211 (here, the placement surface is horizontal) of the support portion 2 (not sandwiched by the pressing portion 22). The position of the liquid supply device 4 is slightly below a plane (substantially corresponding to the lower surface of the substrate) connecting the substrate support locations in the pair of support portions 2. This is to prevent the substrate W from coming into contact with the liquid supply device 4 in an unforeseen situation, and to allow the overflow flow from the liquid supply device 4 to act on the substrate W appropriately. As described above, when the position of the liquid supply device 4 is fixed, the distance is set so as not to come into contact with the discharge port 411 when the substrate W is moved. In the case of the specification of this embodiment, it is desirable that the discharge port 411 is located at a position of 10 to 15 mm downward from the plane. In addition, the liquid supply apparatus 4 can also be installed so that it can be moved up and down by a driving device (not shown). In this case, the discharge port 411 of the liquid supply device 4 can be brought closer to the substrate W to enhance the cleaning effect. The preferable position of the discharge port 411 at the time of the washing | cleaning in that case is 5-15 mm below the said plane, More preferably, it is 5-10 mm. In order to avoid contact with the substrate W more reliably during the movement of the substrate W, it is desirable to lower the liquid supply device 4 further below the above range.

  The liquid supply device 4 is previously filled with the cleaning liquid based on the function of the check valve G4 provided in the pipe K4. In this state, the pump P is operated. As a result, the cleaning liquid is discharged from the nozzle tip 332 of the spraying device 3 and the discharge port 411 of the liquid supply device 4. Then, the amount of spray from the nozzle tip 332 and the amount of overflow from the discharge port 411 are appropriately adjusted by the control valves C2 and C4 on the tubes K2 and K4. An appropriate amount of overflow from the discharge port 411 is determined according to the size and weight of the substrate W, the amount of spray from the spraying device 3, and the like. In the case of the specification of this embodiment, it is usually desirable to set the flow rate so that the flow rate is about 5 to 20 cm / second at the discharge port 411. If the speed is less than 5 cm / sec, the substrate W may be bent and contact the discharge port 411 due to the weight of the substrate W and the spraying force from the spraying device 3. When the speed exceeds 20 cm / sec, the substrate W becomes large and protrudes upward, and the substrate W becomes unstable when the substrate edge is merely placed without being held between the support portions 2. There is a possibility that the support part 2 may come off. Moreover, these fears also arise in the case of clamping by the support portion 2 described later.

  In the spraying device 3, it is desirable that the injection pressure of the nozzle tip 332 is 0.03 to 1.5 MPa, and the total injection amount from the four nozzle tips 332 is about 10 to 240 liters / minute. In addition, the injection direction from a nozzle tip can be variously set as needed. When the injection direction is perpendicular to the substrate surface, it is desirable that the injection pressure of the nozzle tip is 0.02 to 0.5 MPa, and the total injection amount from the nozzle tip is about 4 to 80 liters / minute.

  When cleaning is performed with these specifications, the substrate W is in the state shown in FIG. FIG. 7 schematically shows an overflow flow FL from the substrate W, the support unit 2, the liquid supply device 4, and the discharge port 411. FIG. 7A shows that a distance DS is formed between the discharge port 411 and a plane (substantially corresponding to the lower surface of the substrate) connecting the pair of substrate support portions when the apparatus is not in operation. . FIG. 7B shows a state during cleaning when the distance DS is set to 10 mm, and FIG. 7C shows the state when the distance DS is set to 15 mm (the injection from the spraying device 3 is not shown). A one-dot chain line in the figure indicates the position of the substrate W before the start of cleaning.

  At the time of cleaning, as shown in the figure, the substrate W is slightly bent downward, but the overflow device FL from the liquid supply device 4 exerts a force that attracts the lower surface of the substrate W toward itself, and the spraying device It exerts the upward resistance accompanying the overflow to the sprayed flow from 3. Therefore, by continuing this overflow flow FL during cleaning, the substrate W can be held in a balanced position with respect to forces in both the upper and lower directions. As a result, when the cleaning liquid spray force acts on the upper surface of the substrate, the substrate W is held at a balanced position that also combines the spray force. Thereby, the position of the substrate W can be stably held.

  The liquid supply device 4 can raise the position while overflowing the cleaning liquid while the substrate W is supported, whereby the substrate W is lifted by the overflow flow. In this case, when the substrate W is lifted to the horizontal position while spraying from the spraying device 3, it is possible to more reliably prevent the substrate W from being detached from the support portion 2. Further, when the substrate is in a horizontal state or a state close to this, it is possible to obtain an advantage that solid foreign matters such as solder balls easily flow down as compared with the case where the substrate is concave.

  After the cleaning is continued for the necessary time (usually 5 to 300 seconds) as described above, the operation of the cleaning device 1 is stopped. Stopping is performed first by the spraying device 3 by operating the control valve C2, and then by the liquid supply device 4. The liquid supply device 4 is preferably stopped over a period of time (about 5 seconds) by inverter control of the pump motor or the like. Accordingly, it is possible to reliably prevent the substrate W from dropping from the support device 4. Further, it is more desirable to spray the air from the upper surface of the substrate while the liquid supply device 4 is operated after the spraying device 3 is stopped, so that the substrate is prevented from falling off due to the liquid weight.

  After the cleaning apparatus 1 is stopped, the substrate W is moved to the next station. This movement can be performed by an appropriate means such as a conveyor extending so as to connect the stations of the cleaning facility, or by manual work. Further, cleaning can be performed in parallel at each station. In addition, when the liquid supply apparatus 4 can move up and down, it is desirable to lower the liquid supply apparatus 4 during this movement.

  Next, the above method (ii) (cleaning method for holding the substrate by the support portion) will be described. As shown in FIGS. 6 (a) and 6 (b), the cleaning apparatus 1 used in this method is such that the support part 2 has a high side facing a pair of support parts and a low outside so that The shape is such that the substrate W is sandwiched.

  The first stage of the cleaning method is performed in the same way as in method (i), and the substrate W stops at station S1. Here, the board | substrate W is supported by the support part 2 illustrated to FIG. 6 (a), (b). That is, the substrate W is placed on the placement portion 211 of the support portion 21, and the edge portion is sandwiched by the inner portion 223 of the pressing portion 22. This operation is performed by lowering the lid portion 7 by a driving device (not shown), and the pressing portion 23 coupled to the lid portion pushes down the pressing portion 22.

  When the substrate edge portion is sandwiched in this manner, the substrate W is formed in a convex shape based on the shape of the support portion 2 in which the facing sides of the pair of support portions are raised and the outside thereof is lowered. FIG. 8 shows a state related to this. FIG. 8A shows the state of the substrate W when sandwiched by using the support part 2 of FIG. 6A, and FIG. 8B shows the state of sandwiching by using the support part 2 of FIG. 6B. Each state of the substrate W is shown. 8 (a-1) and (b-1) are the states before the substrate W is placed on the placement portion 211, and (a-2) and (b-2) are the results of the lowering of the inner portion 223. Each of the clamped states is shown.

  In this method, since the liquid supply device 4 is not used, the automatic valve D4 of the pipe K4 connected to the cleaning device 1 is closed. When the pump P is operated in this state, the cleaning liquid is discharged from the nozzle tip 332 of the spraying device 3. Then, the amount of spray from the nozzle tip 332 is appropriately adjusted by the adjustment valve C2 on the pipe K2. The amount of cleaning liquid sprayed from the nozzle tip 332 may be the same as in method (i).

  As described above, since the substrate W is held in an upwardly convex shape in a non-cleaning state, even if the cleaning liquid is sprayed from the spraying device 3 to the top surface of the substrate during cleaning, the spraying force is in the direction along the substrate surface and the substrate surface. As a result, the substrate W is hardly deformed in the direction perpendicular to the surface. (A-3) and (b-3) of FIG. 8 show the state of the substrate W at the time of cleaning corresponding to the support part 2 of FIGS. 6 (a) and 6 (b), respectively. As shown in the figure, the substrate W maintains the upward convex shape although the upward convex shape is slightly lowered. This indicates that the bending of the substrate W is kept small. As for the shape of the support portion 2, the shape of FIG. 6B is higher than the shape of FIG. 6A even if the height difference between the center and the periphery of the substrate W is the same. The radius of curvature of the convex shape can be reduced, and the deformation resistance against the spraying force from above can be increased.

  Note that, depending on the spraying force from the spraying device 3, the substrate has a slightly concave shape or a slightly convex shape at the center of the upward convex shape, as indicated by the alternate long and short dash line in (a-3) and (b-3) of FIG. May produce a planar shape. Also in this case, since the other portions are held in an upward convex shape, the above-mentioned spraying force dispersion effect is obtained, and the bending effect is effectively obtained.

  In this way, after the cleaning is performed, the pump P is stopped, and if necessary, air is blown from the upper surface of the substrate to drain the liquid. Thereafter, the holding portion 22 is raised together with the lid portion 7 to release the holding of the substrate W, and the substrate W is moved to the next station. This movement is performed in the same manner as in method (i).

  Next, the above method (iii) (a cleaning method using both (i) and (ii) above) will be described. This method is performed using the liquid supply device 4 in (i) and the support device 4 in (ii). First, the substrate W is moved along the guide rail G and stopped at the station S1. At this position, the substrate W is placed on the placement portion 211 of the support portion 21, and the edge portion is sandwiched by the inner portion 223 of the pressing portion 22. In this state, the pump P is operated, and the amount of spray from the nozzle tip 332 and the amount of overflow from the discharge port 411 are adjusted by the control valves C2 and C4 on the pipes K2 and K4.

  After the cleaning is performed in this manner, the spraying device 3 is stopped, and if necessary, air is blown from the upper surface of the substrate to drain the liquid, and then the liquid supply device 4 is stopped. Thereafter, the holding portion 22 is raised together with the lid portion 7 to release the holding of the substrate W, and the substrate W is moved to the next station. The details of other operations and the like in the method (iii) are the same as those in the methods (i) and (ii), and thus the description thereof is omitted. When the liquid supply device 4 is installed so as to be movable up and down, as described in the method (i), the liquid supply device 4 is moved below the cleaning position when the substrate W is moved into and out of the station. It is desirable to lower.

  Next, an experiment in which the substrate is cleaned with the following specifications will be described. The experimental specifications are referred to as specifications (i), (ii), and (iii) corresponding to the above methods (i), (ii), and (iii). Further, those not adopting the specifications according to the present invention (the mounting portion 211 of the support portion 2 is horizontal, is not gripped by the pressing portion 22, and does not overflow from the liquid supply device 4) are referred to as a specification (0). . In addition, a part of the specification (iii) is changed, the liquid supply device 4 is installed so as to be movable up and down, and the liquid supply device 4 is raised until the substrate W gripped by the support portion 2 becomes horizontal. This is referred to as specification (iiia). Other specifications are as follows.

Dimensions of substrate W: Width (dimension between support parts) 242 mm, length 305 mm, thickness 1, 0.5, 0.4, 0.3, 0.2 mm
Material of substrate W: copper-clad plate (with 35 μm thick copper foil pasted on both sides of glass epoxy resin plate) and glass-epoxy resin wiring board (after each wiring is formed on both sides of copper-clad plate, each surface Covered with insulating film)
Placement part 211 of support part 2:
In specifications (0) and (i), horizontal (hereinafter referred to as “support part horizontal”),
6 (a) and 6 (b) adopted in the specifications (ii), (iii), and (iiia), FIG. 6 (a) type has an inclination of 5 degrees (hereinafter referred to as “support portion inclination”),
In the type shown in FIG. 6B, the curvature radius is 7 mm, and the inclination angle of the substrate tangent at the edge of the mounting portion is 5 degrees (hereinafter referred to as “supporting portion concave shape”)
Inner diameter of discharge port of liquid supply device 4: 50 mm
Position of liquid supply device 4: 10 mm from a plane connecting the substrate support portions of the pair of support portions 2
Overflow from liquid supply device 4: Flow velocity at discharge port: 12 cm / second Liquid injection from spray device 3: Pressure 1 MPa, flow rate 100 liters / minute Cleaning time: 15 seconds injection x 6 times (stop time between injections 15 seconds )
A cleaning experiment was performed according to the above specifications, and the results shown in Table 1 were obtained. In the table, “◯” indicates that the substrate W did not fall off during the cleaning, and “x” indicates that the substrate W was detached from the support portion 2 during the cleaning.

この結果から明らかなように、本発明の構成を採用しない仕様(0)では１ｍｍ厚の銅板及びガラスエポキシ樹脂、並びに０．５ｍｍ厚の銅板の場合にしか基板の脱落を防止できなかった。これに対し、本発明の構成を採用した仕様(i),(ii),(iii),(iiia)では、より薄い基板の場合でも洗浄中の脱落をより有効に防止している。

As is clear from this result, in the specification (0) in which the configuration of the present invention is not adopted, the dropout of the substrate can be prevented only in the case of a 1 mm thick copper plate and glass epoxy resin and a 0.5 mm thick copper plate. On the other hand, in the specifications (i), (ii), (iii), and (iiia) adopting the configuration of the present invention, even when the substrate is thinner, it is more effectively prevented from falling off during cleaning.

  The present invention is not limited to the above embodiment, and various modifications can be made. For example, the overflow from the liquid supply device 4 may be a liquid (cleaning liquid, water, or other liquid) from a separate supply source without being shared with the cleaning liquid from the spraying device 3.

  The cleaning apparatus may be a continuous processing apparatus that performs cleaning while transporting the substrate. In this case, for example, as shown in FIG. 9, the liquid supply device 4 ′ is slightly narrower than the width direction of the substrate W, and the substrate W is transported in the direction of the arrow TR to overflow the liquid from the discharge port 411 ′. However, the cleaning liquid can be sprayed onto the upper surface of the substrate W from a spraying device (not shown).

The washing equipment provided with the washing device concerning the present invention is shown, (a) is a top view and (b) is a front view. It is the schematic of one station in the washing | cleaning installation of FIG. It is a longitudinal view of the washing | cleaning apparatus currently used for the washing | cleaning installation of FIG. It is explanatory drawing which shows the operation state of the washing | cleaning apparatus of FIG. It is a perspective view which shows the support part in the washing | cleaning apparatus of FIG. 3 with a board | substrate. It is a longitudinal cross-sectional view of the principal part of the support part shown in FIG. It is explanatory drawing of the operation state of the washing | cleaning apparatus of FIG. It is explanatory drawing of the operation state of the washing | cleaning apparatus of FIG. It is a perspective view which shows the principal part about other embodiment of the washing | cleaning apparatus which concerns on this invention. It is a longitudinal cross-sectional view which shows the conventional washing | cleaning apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cleaning apparatus 2 Support part 3 Spraying apparatus 4 Liquid supply apparatus 21 Support part 22 Press part 23 Press part 211 Placement part 411 Discharge port

Claims (18)

A cleaning method for cleaning an upper surface of a thin substrate by supporting opposite edges of the thin substrate and spraying a cleaning liquid onto the upper surface of the substrate, and supplying a liquid supply device for supplying the liquid along the lower surface of the substrate A method for cleaning a thin substrate , wherein the substrate is supported from below by continuously overflowing a liquid from a discharge port provided so as to open, and the substrate is held while the substrate is held . The opposing edge portions of the thin substrate are placed on a placement surface provided on the placement portion for placing the substrate, and the edge of the substrate is brought into contact with the rising portion rising from the placement portion. The cleaning method according to claim 1, wherein the substrate is supported by. The cleaning method according to claim 1, wherein the substrate is held by sandwiching opposing edges of the thin substrate from above and below. The cleaning method according to claim 3, wherein opposite edges of the thin substrate are sandwiched from above and below so that the substrate has a convex shape upward at least in a non-cleaning state. A cleaning method of cleaning the upper surface by holding the substrate by spraying a cleaning liquid onto the upper surface of the substrate by supporting the opposing edges of the thin substrate with a pair of support portions,
Each of the pair of support portions is provided for supporting a support portion having a placement portion provided with a placement surface for placing an edge portion of the substrate, and a substrate placed on the placement surface. It has a holding part,
The mounting surface in one support part and the mounting surface in the other support part are inclined such that the edge on the opposite side is high and the opposite side is low, or each has a concave shape below,
The substrate is held in a convex shape at least in a non-cleaned state by holding the substrate by holding the substrate from above and below with the support portion and the pressing portion , and supplying the liquid to the substrate. A thin substrate cleaning method, wherein the cleaning is performed while the substrate is supported from below by continuously overflowing liquid from an outlet provided so as to open along the lower surface. The cleaning method according to claim 1, wherein the substrate is supported so that the liquid that continues to overflow from the discharge port does not contact the peripheral edge of the lower surface of the substrate. The cleaning method according to claim 1, wherein the thin substrate is a substrate having a width of 10 to 600 mm, a length of 10 to 800 mm, and a thickness of 0.1 to 2 mm. The cleaning method according to claim 1, wherein the thin substrate is a printed board or a printed wiring board. Supporting the substrate by a respective outlet of a plurality of the liquid supply device continues to spill the liquid, cleaning method according to any one of claims 1 to 8. A support portion for holding the substrate by supporting opposite edges of the thin substrate;
A spraying device for spraying a cleaning liquid on the upper surface so as to clean the upper surface of the substrate;
A liquid supply device that includes a discharge port that opens along the lower surface of the substrate and supports the substrate from below by continuing to overflow the liquid from the discharge port;
An apparatus for cleaning a thin substrate, comprising: The support portion includes a placement portion provided with a placement surface for placing an edge portion of the substrate, and an upright portion for rising and contacting the edge of the substrate from the placement portion. The cleaning apparatus according to claim 10, comprising: The cleaning device according to claim 10, wherein the support portion sandwiches opposing edges of the thin substrate from above and below. The cleaning device according to claim 12, wherein the support portion sandwiches opposing edges of the thin substrate from above and below so that the substrate has a convex shape upward at least in a non-cleaning state. A pair of support portions for holding the substrate by supporting the opposing edge portions in the thin substrate, the support portion including a placement portion provided with a placement surface for placing the edge portion of the substrate; And the pair of support parts having a pressing part for pressing the substrate placed on the mounting surface ,
A spraying device for spraying a cleaning liquid on the upper surface so as to clean the upper surface of the substrate;
And a liquid supply device for supporting the substrate from below by the exhaust outlet comprises an outlet opening along the lower surface of the substrate continues to spill the liquid,
The pair of support portions are end edges on the side where the mounting surface in one supporting portion and the mounting surface in the other supporting portion face each other so that the substrate is held in a convex shape upward at least in a non-cleaned state. The thin substrate is characterized in that it is inclined so that the opposite side is low, or has a concave shape on the lower side, and is configured to sandwich the substrate from above and below by the support portion and the pressing portion . Cleaning device. The cleaning apparatus according to claim 10, wherein the substrate is supported such that the liquid that continues to overflow from the discharge port does not come into contact with a peripheral edge portion of the lower surface of the substrate. The cleaning apparatus according to claim 10, wherein the thin substrate is a substrate having a width of 10 to 600 mm, a length of 10 to 800 mm, and a thickness of 0.1 to 2 mm. The said thin substrate is a washing | cleaning apparatus in any one of Claims 10-16 which is a printed circuit board or a printed wiring board. Comprising a plurality of the liquid supply apparatus, the cleaning device according to any one of claims 10 to 17.

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