JP4951414B2 - Circuit board clamping method and screen printing machine - Google Patents

Description

  The present invention relates to a method of clamping a circuit board when printing cream solder on a circuit board through a screen mask, and a screen printer.

  For example, Patent Document 1 discloses a screen printing machine having a squeegee device and a side clamp device. The side clamp device holds a circuit board to be printed. The squeegee device is disposed immediately above the side clamp device. The squeegee device prints cream solder on the circuit board held by the side clamp device through the pattern hole of the screen mask.

  Hereinafter, a method for clamping a circuit board in a conventional screen printer will be described. A conventional circuit board clamping method includes an edge clamp entry process, a temporary clamp process, a side clamp exit process, a first surface alignment process, a main clamp process, a separation process, an edge clamp exit process, And a surface alignment process.

  FIG. 16 shows a timing chart of a circuit board clamping method in a conventional screen printing machine. FIG. 17 shows a schematic diagram of the screen printing machine. FIG. 18 shows a schematic diagram in the edge clamp approach process of the screen printing machine. FIG. 19 shows a schematic diagram in the temporary clamping process of the screen printing machine. FIG. 20 shows a schematic diagram in the side clamp withdrawal process of the screen printing machine. In FIG. 21, the schematic diagram in the 1st surface alignment process of the screen printing machine is shown. FIG. 22 shows a schematic diagram in the main clamping process of the screen printing machine. In FIG. 23, the schematic diagram in the 2nd surface alignment process of the screen printing machine is shown.

  As shown in FIG. 17, the screen printing machine 100 includes a side clamp device 101, a positioning device 102, a cylinder device 103, an edge clamp device 104, a conveyor device 105, and a first table 106. . The circuit board B1 is placed on the upper surfaces of the pair of belts 105a and 105b of the conveyor device 105.

  In the edge clamp entry process, as shown in FIG. 18, the pair of edge clamps 104a and 104b are entered just above both side edges of the circuit board B1 (step S100 in FIG. 16).

  In the temporary clamping step, as shown in FIG. 19, the positioning device 102 is driven to move the nut portion 102b along the ball screw 102a (step S101 in FIG. 16). Here, the air pressure in the cylinder main body 103a is maintained at a relatively high pressure (as shown in FIG. 16, the air pressure in the cylinder device 103 is constant). For this reason, the substantially full length of the piston rod 103b protrudes from the cylinder main body 103a. When the nut portion 102b is moved, the slave clamp 101a moves in a direction close to the reference clamp 101b via the piston rod 103b. For this reason, the circuit board B1 is pushed by the subordinate clamp 101a and is shifted to the reference clamp 101b side. The circuit board B1 after being offset is sandwiched between the subordinate clamp 101a and the reference clamp 101b.

  In the side clamp withdrawal process, as shown in FIG. 20, the positioning device 102 is driven in reverse to separate the slave clamp 101a from the reference clamp 101b (step S102 in FIG. 16). For this reason, the circuit board B <b> 1 is released from the side clamp device 101. A gap W1 is secured between the slave clamp 101a and the circuit board B1.

  In the first surface alignment step, as shown in FIG. 21, the first table 106 and the second table (not shown) are raised to bring the upper surface of the side clamp device 101 and the upper surface of the circuit board B1 into the edge clamp device 104. It strikes against the lower surface (steps S103 and S104 in FIG. 16). Then, the upper surface of the side clamp device 101 and the upper surface of the circuit board B1 are substantially flush with each other.

  In this clamping process, as shown in FIG. 22, the positioning device 102 is driven, and the slave clamp 101a that has once retracted is again brought close to the reference clamp 101b (step S105 in FIG. 16). Then, the circuit board B1 is sandwiched again between the slave clamp 101a and the reference clamp 101b.

  The separation process is performed in parallel with the clamping process. In the separation step, the side clamp device 101 and the circuit board B1 are once lowered (step S106 in FIG. 16), and the lower surface of the edge clamp device 104 is separated from the upper surface of the side clamp device 101 and the upper surface of the circuit board B1.

  In the edge clamp withdrawal process, the edge clamp device 104 is retracted to a position where it does not interfere with the side clamp device 101 and the circuit board B1 (step S107 in FIG. 16).

  In the second surface alignment step, as shown in FIG. 23, the side clamp device 101 and the circuit board B1 are raised again so that the upper surface of the side clamp device 101, the upper surface of the circuit board B1, and the upper surface of the edge clamp device 104 are substantially They are aligned (step S108 in FIG. 16).

Thereafter, cream solder is printed on the circuit board B1 held by the side clamp device 101 through the pattern hole of the screen mask by an upper squeegee device (not shown).
JP 2006-281712 A

  As described above, the conventional circuit board clamping method includes an edge clamp entry process, a temporary clamp process, a side clamp exit process, a first surface alignment process, a main clamp process, a separation process, and an edge clamp exit process. It had a process and a second surface alignment process.

  However, according to the conventional circuit board clamping method, the side clamp device 101 has a large impact when the circuit board B1 is held. For this reason, there is a possibility that a problem may occur when the thickness of the circuit board B1 is thin or when the material of the circuit board B1 is ceramic.

  That is, in the first surface aligning step, as shown in FIG. 21, the upper surface of the side clamp device 101 and the upper surface of the circuit board B1 need to be approximately flush with each other. For this reason, in the side clamp withdrawal process, which is the previous process, the slave clamp 101a is once separated from the circuit board B1 as shown in FIG. Therefore, a gap W1 is generated between the dependent clamp 101a and the circuit board B1.

  In this clamping step, as shown in FIG. 22, the gap W1 is consumed at a stretch, and the circuit board B1 is sandwiched between the subordinate clamp 101a and the reference clamp 101b. For this reason, for example, when the board thickness of the circuit board B1 is thin, the circuit board B1 may be warped.

  Thus, according to the conventional circuit board clamping method, there is a large impact when the circuit board B1 is sandwiched, and there are problems such as when the board thickness of the circuit board B1 is thin or the material of the circuit board B1 is ceramic. There was a risk of occurrence.

  The circuit board clamping method and screen printing machine of the present invention have been completed in view of the above problems. Therefore, the present invention provides a circuit board that has a low impact when pinching the circuit board and is less likely to cause a problem even when the circuit board is thin or the circuit board is made of ceramic. It is an object to provide a clamping method and a screen printing machine.

  (1) In order to solve the above-described problem, a circuit board clamping method according to the present invention includes a reference clamp and a subordinate clamp arranged at a predetermined interval with respect to the reference clamp. A side clamp device capable of sandwiching opposite side edges of the circuit board from the side with the subordinate clamp, a guide portion extending in the juxtaposing direction in which both the reference clamp and the subordinate clamp are arranged, and the guide portion A positioning device having a guided portion that moves along, a cylinder main body interposed between the guided portion and the subordinate clamp, and a piston rod inserted into the cylinder main body, A cylinder device that reciprocates the piston rod by the pressure of fluid inside the cylinder body, and moves at least one of the guided portion and the piston rod. A circuit board clamping method in a screen printing machine capable of changing a distance between the reference clamp and the subordinate clamp by holding the fluid pressure of the cylinder body at a predetermined pressure, or By moving the guided portion while reducing the pressure of the fluid, the subordinate clamp is brought close to the reference clamp, and the subordinate clamp, the circuit board, and the reference clamp are connected in the juxtaposed direction of both the clamps. A temporary clamping step of shifting the circuit board to the reference clamp side until the connection state is established, and the pressure of the fluid in the cylinder body is lowered while the connection state is maintained, so that the circuit board is bent by the displacement. A pressure reducing step for suppressing the remaining of the gas, and increasing the pressure of the fluid in the cylinder body while maintaining the connected state. Pressing the pump, and having a a book clamp step of clamping the circuit board between the reference clamp and the driven genus clamp (corresponding to claim 1).

  The circuit board clamping method of the present invention includes a temporary clamping step, a decompression step, and a main clamping step. In the temporary clamping process, the dependent clamp is brought close to the reference clamp. Then, the circuit board is shifted to the reference clamp side. The misalignment is performed until the slave clamp, the circuit board, and the reference clamp are connected in the juxtaposed direction. That is, after the temporary clamping process, the slave clamp, the circuit board, and the reference clamp are connected to each other. In the depressurization step, the pressure of the fluid in the cylinder body is lowered without moving the guided portion and in the connected state. For this reason, the clamping force applied to the circuit board being clamped is reduced. In the present clamping step (of course, not necessarily immediately after the pressure-reducing step), the pressure of the fluid in the cylinder body is increased while maintaining a substantially connected state. And the clamping force added to a circuit board is enlarged.

  Thus, the circuit board clamping method of the present invention includes a pressure reducing step after the temporary clamping step. For this reason, even if the circuit board is bent due to the clamping force in the temporary clamping step (see FIG. 19), the reduced clamping force is used as the elastic restoring force of the circuit board itself in the decompression step. By relatively exceeding, it is possible to suppress the bending remaining on the circuit board.

  In the decompression step, the dependent clamp is not driven using the guided portion. For this reason, the connection state of the subordinate clamp, the circuit board, and the reference clamp remains substantially maintained. Therefore, there is little possibility that a gap W1 as shown in FIGS. 20 and 21 is generated between the subordinate clamp and the circuit board. Therefore, when driving the subordinate clamp in this clamping step, the impact that the subordinate clamp has on the circuit board can be reduced. When the impact is small, the possibility of occurrence of a problem is reduced even when the thickness of the circuit board is thin or the circuit board is made of ceramic.

  (2) Preferably, in the configuration of the above (1), further, while suppressing an increase in the pressure of the fluid in the cylinder body after the decompression step or in parallel with the decompression step, By moving the guided portion, the guided portion is brought close to the subordinate clamp, the piston rod is relatively immersed in the cylinder body, and a projection margin of the piston rod is secured in the main clamping step. It is better to have a projecting margin securing step (corresponding to claim 2).

  If the protrusion of the piston rod with respect to the cylinder body after the temporary clamping process is large, even if the fluid pressure of the cylinder body is increased in this clamping process, the remaining protrusion of the piston rod is small and the slave clamp cannot be driven sufficiently. There is a fear.

  In this regard, according to the protrusion allowance securing step of this configuration, the remaining protrusion allowance of the piston rod can be recovered. In the protrusion allowance securing step, the guided portion is brought close to the dependent clamp while suppressing an increase in the fluid pressure of the cylinder body. For this reason, the piston rod is relatively immersed in the cylinder body. By the immersion operation, it is possible to secure a protrusion margin of the piston rod in the main clamping process. Further, since the guided portion is brought close to the subordinate clamp while suppressing an increase in the fluid pressure of the cylinder body, it is possible to suppress an increase in the pressing force applied to the circuit board from the subordinate clamp.

  (3) Preferably, in the configuration of the above (1) or (2), further after the decompression step and before the main clamping step, the upper surface of the circuit board is maintained in the substantially connected state; The upper surface of the reference clamp and the upper surface of the subordinate clamp may be substantially flush with each other, or it may be configured to have an upper surface disposing step of disposing the upper surface of the circuit board so as to relatively protrude. 3).

  The cream solder is printed on the upper surface of the circuit board. In this regard, according to the present configuration, the upper surface of the circuit board is not disposed below the upper surface of the reference clamp or the upper surface of the subordinate clamp. For this reason, it is easy to print cream solder on the circuit board.

  In the upper surface arranging step, the positions of the upper surface of the circuit board, the upper surface of the reference clamp, and the upper surface of the subordinate clamp are adjusted while maintaining a substantially connected state. At the time of position adjustment, the circuit board and at least one of the reference clamp and the dependent clamp are in sliding contact with each other. For this reason, if the sliding resistance is large, smooth position adjustment becomes difficult.

  However, a decompression step is set before the top surface placement step. In the decompression step, the clamping force on the circuit board is reduced by reducing the pressure of the fluid in the cylinder body. For this reason, according to this structure, the sliding resistance between a circuit board and at least one of a reference | standard clamp and a subordinate clamp is small. Therefore, according to this configuration, the upper surface arranging step can be performed smoothly.

  (4) Preferably, in the configuration of (3) above, the screen printing machine is further arranged on the outer side of the side clamp device in the juxtaposed direction of both clamps, and a pair of edges that can enter the inner side of the juxtaposed direction of both clamps. An edge clamp device having a clamp, and further comprising an edge clamp entry step for allowing the pair of edge clamps to enter just above the opposite side edges of the circuit board before the top surface placement step, In the upper surface arranging step, the upper surface of the both side edges of the circuit board, the upper surface of the reference clamp, and the upper surface of the dependent clamp are brought into contact with the pair of edge clamps after entering from below, The upper surface of the circuit board, the upper surface of the reference clamp, and the upper surface of the subordinate clamp are preferably configured to be a first surface alignment process in which the upper surfaces of the dependent clamps are arranged substantially flush with each other. (Corresponding to claim 4).

  According to this configuration, the upper surface of the circuit board, the upper surface of the reference clamp, and the upper surface of the subordinate clamp are arranged substantially flush with each other using the lower surfaces of the pair of edge clamps. For this reason, surface matching can be performed easily.

  (5) Preferably, in the configuration of (4), a pair of the edge clamps, the circuit board, the reference clamp, and the subordinates are further provided after the main clamping step or in parallel with the main clamping step. A separation step of relatively separating the clamps in the vertical direction, and an edge clamp exiting step of retracting the pair of edge clamps to positions that do not interfere with the circuit board, the reference clamp, and the subordinate clamp, and In addition to the upper surface of the circuit board, the upper surface of the reference clamp, and the upper surface of the subordinate clamp that are arranged flush with each other, the upper surfaces of the pair of edge clamps are also arranged in a substantially flush manner. It is better to have an arrangement step (corresponding to claim 5).

  According to this configuration, in addition to the upper surface of the circuit board, the upper surface of the reference clamp, and the upper surface of the dependent clamp, the upper surfaces of the pair of edge clamps can be arranged substantially flush with each other. For this reason, when printing cream solder on the upper surface of a circuit board, it can suppress that a pair of edge clamp interferes with a screen mask etc., for example.

  (6) Moreover, in order to solve the said subject, the screen printer of this invention has a reference | standard clamp and the subordinate clamp arrange | positioned at predetermined intervals with respect to this reference | standard clamp, and this reference | standard clamp A side clamp device capable of sandwiching opposite side edges of the circuit board from the side with the subordinate clamp, a guide portion extending in the juxtaposing direction in which both the reference clamp and the subordinate clamp are arranged, and the guide portion A positioning device having a guided portion that moves along, a cylinder main body interposed between the guided portion and the subordinate clamp, and a piston rod inserted into the cylinder main body, A cylinder device that reciprocates the piston rod by the pressure of fluid inside the cylinder body, and moves at least one of the guided portion and the piston rod. A screen printing machine capable of changing a distance between the reference clamp and the subordinate clamp, while maintaining the fluid pressure of the cylinder body at a predetermined pressure or lowering the fluid pressure. However, by moving the guided portion, the subordinate clamp is brought close to the reference clamp, and the subordinate clamp, the circuit board, and the reference clamp are connected to each other in the juxtaposed direction. In order to suppress the circuit board from being biased to the reference clamp side, and to prevent the deflection from remaining on the circuit board by the biasing, the pressure of the fluid in the cylinder body is lowered, and the The subordinate clamp is pressed by increasing the pressure of the fluid in the cylinder body in the connected state, and the circuit board is interposed between the reference clamp and the subordinate clamp. Characterized by clamping (corresponding to claim 6).

  According to the screen printing machine of the present invention, the pressure of the fluid in the cylinder body is reduced in the connected state. For this reason, when creating a connected state, even if the circuit board bends due to the clamping force between the subordinate clamp and the reference clamp, the clamping force reduced by the reduced pressure relatively exceeds the elastic restoring force of the circuit board itself, It is possible to suppress the bending from remaining on the circuit board.

  In addition, the slave clamp is not driven using the guided portion during decompression. For this reason, the connection state of the subordinate clamp, the circuit board, and the reference clamp remains substantially maintained. Therefore, there is little possibility that a gap W1 as shown in FIGS. 20 and 21 is generated between the subordinate clamp and the circuit board. Therefore, when the clamping force to the circuit board is increased again (when the slave clamp is driven), the impact of the slave clamp on the circuit board is small.

  According to the present invention, it is possible to provide a circuit board clamping method and a screen printing machine that have a small impact when sandwiching a circuit board.

  Hereinafter, embodiments of a circuit board clamping method and a screen printing machine according to the present invention will be described.

<First embodiment>
[Configuration of screen printer]
First, the configuration of the screen printing machine of this embodiment will be described. FIG. 1 shows a side view of the screen printing machine of the present embodiment. As shown in FIG. 1, the screen printing machine 1 of this embodiment includes a movable part 8 and a support part 9.

  The support unit 9 mainly includes a lifting table 90, a support column 91, and a lifting device 92. The support column 91 extends in the vertical direction. A guide rail 910 is disposed on the front surface of the column 91. The guide rail 910 extends in the vertical direction.

  The lifting table 90 includes a flat frame portion 900 and a guided column 901. The guided column 901 extends in the vertical direction. The guided column 901 includes a guided recess 902 and a nut portion 903. The guided recessed portion 902 is engaged with the guide rail 910. The guided recessed portion 902 is slidable in the vertical direction along the guide rail 910. The flat frame portion 900 is disposed above the guided column 901. The flat frame portion 900 extends in the horizontal direction.

  The lifting device 92 includes a motor 920 and a ball screw 921. The nut portion 903 of the guided column 901 is screwed into the ball screw 921. When the motor 920 moves, the ball screw 921 rotates. For this reason, the nut portion 903 is movable along the extending direction of the ball screw 921. Therefore, the elevating table 90 can move in the vertical direction while the guided recess 902 is guided by the guide rail 910 by the driving force transmitted to the nut portion 903.

  The movable portion 8 mainly includes the side clamp device 2, the positioning device 3, the edge clamp device 5, the side clamp cylinder device 40, the edge clamp cylinder devices 41a and 41b, the first table 60, the second table 61, and the third. A table 62 and a conveyor device 7 are provided. The movable part 8 is mounted on the lifting table 90. For this reason, the movable part 8 can move in the vertical direction together with the lifting table 90.

  The third table 62 has a rectangular plate shape. The third table 62 is mounted on the upper surface of the flat frame portion 900 via a ball bearing 620. For this reason, the third table 62 can move back and forth and right and left with respect to the flat frame portion 900. As well as rotating.

  An edge clamp guide rail 623 extending in the front-rear direction is embedded in the third table 62. In addition, a cam guide rail 621 extending in the front-rear direction is disposed on the upper surface of the third table 62. A pair of front and rear cam members 622 are engaged with the cam guide rail 621. The pair of cam members 622 can slide in the front-rear direction along the cam guide rails 621. The cam member 622 has a right triangular shape. The cam member 622 has an inclined surface that descends from the rear toward the front.

  The edge clamp device 5 includes a pair of edge clamps 5a and 5b. The edge clamp 5a is disposed opposite to the rear edge of the third table 62, and the edge clamp 5b is disposed opposite to the front edge of the third table 62. In FIG. 2, the perspective view of the upper part of the movable part 8 of the screen printer 1 of this embodiment is shown. FIG. 3 shows an exploded perspective view of the upper part of the movable part 8 of the screen printing machine 1. In FIG. 2, the edge clamp 5a is shown in a transparent manner for convenience of explanation.

  The edge clamp 5a includes a base portion 50a, a claw portion 51a, and a spring 52a. The base 50a has a prismatic shape. A lower end portion of the base portion 50 a is embedded in the third table 62. The lower end of the base 50a is engaged with the edge clamp guide rail 623. Therefore, the base 50a, that is, the edge clamp 5a is movable in the front-rear direction along the edge clamp guide rail 623. The claw portion 51a has an L shape whose top is refracted forward. The top of the claw portion 51a has a flat plate shape. The lower end portion of the claw portion 51a is accommodated in the upper end portion of the base portion 50a. The nail | claw part 51a can move to an up-down direction with respect to the base 50a. The spring 52a connects the claw portion 51a and the base portion 50a. The spring 52a urges the claw portion 51a and the base portion 50a in a direction approaching each other.

  The configuration of the edge clamp 5b is the same as the configuration of the edge clamp 5a. That is, the edge clamp 5b includes a base portion 50b, a claw portion 51b, and a spring 52b. The base 50b, that is, the edge clamp 5b is movable in the front-rear direction along the edge clamp guide rail 623. The claw portion 51b has an L shape whose top is refracted rearward. The claw portion 51b is movable in the vertical direction with respect to the base portion 50b. The spring 52b biases the claw portion 51b and the base portion 50b in a direction in which they are close to each other.

  The second table 61 has a rectangular plate shape. The second table 61 is disposed substantially at the center of the third table 62. The second table 61 is guided by a guide rod 605 described later, and can move only in the vertical direction. A pair of rollers 610 are disposed on the lower surface of the second table 61 so as to be separated from each other in the front-rear direction. The pair of rollers 610 can roll on the inclined surfaces of the pair of cam members 622. For this reason, the 2nd table 61 can be raised by moving the cam member 622 ahead. Conversely, the second table 61 can be lowered by moving the cam member 622 backward.

  The side clamp device 2 includes a slave clamp 2a and a reference clamp 2b. The slave clamp 2 a is disposed at the rear edge of the second table 61, and the reference clamp 2 b is disposed at the front edge of the second table 61. The dependent clamp 2a has a flat plate shape whose upper end protrudes forward. The reference clamp 2b has a flat plate shape whose upper end protrudes rearward.

  The conveyor device 7 includes a pair of belt conveyors 7a and 7b. The belt conveyor 7a is disposed in the vicinity of the upper edge of the front surface of the dependent clamp 2a. The belt conveyor 7a extends in the left-right direction (hereinafter, left and right are defined with reference to the case of looking from the front to the rear). The belt conveyor 7a includes an endless annular belt 70a. The belt conveyor 7b is disposed in the vicinity of the upper edge of the rear surface of the reference clamp 2b. The belt conveyor 7b extends in the left-right direction so as to face the belt conveyor 7a. The belt conveyor 7b includes an endless annular belt 70b. A rectangular plate-like circuit board B is placed on the pair of belt conveyors 7a and 7b in a bridging manner.

  The positioning device 3 includes a ball screw 30 and a nut portion 31. The ball screw 30 is included in the guide portion of the present invention. The nut portion 31 is included in the guided portion of the present invention. The ball screw 30 is embedded in the second table 61. The ball screw 30 extends in the front-rear direction. A pair of ball screws 30 are arranged in the left-right direction. The nut portion 31 includes a nut body 310 and a bracket 311. The bracket 311 has a flat plate shape. The bracket 311 is juxtaposed behind the dependent clamp 2a. A pair of nut main bodies 310 are disposed in the left-right direction at the lower edge of the rear surface of the bracket 311. The pair of nut main bodies 310 are respectively screwed into the pair of ball screws 30.

  The side clamp cylinder device 40 includes a cylinder body 400 and a piston rod 401. The side clamp cylinder device 40 is included in the cylinder device of the present invention. The cylinder body 400 has a cylindrical shape. A pair of left and right cylinder bodies 400 are arranged on the rear surface of the bracket 311. Air can be supplied and discharged into the cylinder body 400 from an air pipe (not shown). The piston rod 401 extends in the front-rear direction. The rear end of the piston rod 401 is accommodated in the cylinder body 400. The front end of the piston rod 401 passes through the bracket 311 and is in contact with the rear surface of the dependent clamp 2a.

  The edge clamp cylinder device 41a includes a cylinder body 410a and a piston rod 411a. The cylinder body 410a has a cylindrical shape. A pair of left and right cylinder bodies 410 a are disposed on the rear surface of the bracket 311. Air can be supplied and discharged from an air pipe (not shown) into the cylinder body 410a. The piston rod 411a extends in the front-rear direction. The front end of the piston rod 411a is accommodated in the cylinder body 410a. The rear end of the piston rod 411a is in contact with the front surface of the base 50a of the edge clamp 5a.

  The configuration of the edge clamp cylinder device 41b is the same as the configuration of the edge clamp cylinder device 41a. That is, the edge clamp cylinder device 41b includes a cylinder body 410b and a piston rod 411b. A pair of left and right cylinder bodies 410b are arranged on the front surface of the reference clamp 2b. Air can be supplied and discharged into the cylinder body 410b. The piston rod 411b extends in the front-rear direction. The rear end of the piston rod 411b is accommodated in the cylinder body 410b. The front end of the piston rod 411b is in contact with the rear surface of the base 50b of the edge clamp 5b.

  The first table 60 includes a table main body 600, an elevating member 601, a nut portion 602, a ball screw 603, a motor 604, and a guide rod 605. The table body 600 has a rectangular plate shape. The table main body 600 is disposed substantially at the center of the second table 61. The elevating member 601 has a rectangular plate shape. The elevating member 601 supports the table main body 600. The nut portion 602 is disposed on the lower surface of the elevating member 601. The motor 604 is housed inside the third table 62 and the flat frame portion 900. The ball screw 603 is disposed immediately above the motor 604. The ball screw 603 passes through the second table 61. A nut portion 602 is screwed onto the upper end of the ball screw 603. The guide rod 605 is disposed through the second table 61 between the lower surface of the elevating member 601 and the upper surface of the third table 62. The guide rod 605 can be expanded and contracted in the vertical direction. The guide rods 605 are disposed at the four corners on the lower surface of the elevating member 601. As described above, the guide rod 605 guides the vertical movement of the second table 61. When the motor 604 is driven, the ball screw 603 rotates. For this reason, the screwing amount of the nut part 602 with respect to the ball screw 603 changes. The elevating member 601 and the table main body 600 can move in the vertical direction by the change in the screwing amount.

[Clamping method of circuit board]
Next, a method for clamping the circuit board B in the screen printing machine 1 of the present embodiment will be described. The circuit board clamping method of the present embodiment includes an edge clamp entry process, a temporary clamp process, a pressure reduction process, a first surface alignment process, a protrusion allowance securing process, a main clamping process, a separation process, and an edge clamp. A withdrawal step and a second surface alignment step.

  FIG. 4 shows a timing chart of the circuit board clamping method of this embodiment. FIG. 5 shows a schematic diagram of the screen printing machine of the present embodiment. In FIG. 6, the schematic diagram in the edge clamp approach process of the screen printing machine is shown. In FIG. 7, the schematic diagram in the temporary clamp process of the screen printing machine is shown. In FIG. 8, the schematic diagram in the pressure reduction process of the screen printing machine is shown. In FIG. 9, the schematic diagram in the 1st surface alignment process of the screen printing machine is shown. In FIG. 10, the schematic diagram in the protrusion margin ensuring process of the screen printing machine is shown. In FIG. 11, the schematic diagram in this clamp process of the screen printing machine is shown. FIG. 12 shows a schematic diagram in the separation process of the screen printing machine. FIG. 13 shows a schematic diagram in the edge clamp withdrawal process of the screen printing machine. In FIG. 14, the schematic diagram in the 2nd surface alignment process of the screen printing machine is shown.

  The circuit board B is carried from a stocker (not shown) onto the pair of belt conveyors 7a and 7b as shown in FIG. During transport, the front-rear direction interval between the sub-clamp 2a and the reference clamp 2b is smaller than the front-rear direction width of the circuit board B in order to suppress interference between the circuit board B, the sub-clamp 2a, and the reference clamp 2b. It is set slightly larger.

  In the edge clamp entry process, as shown in FIG. 6, the claw portion 51a of the edge clamp 5a and the claw portion 51b of the edge clamp 5b are entered to just above both side edges of the circuit board B (step S1 in FIG. 4). .

  In the temporary clamping step, as shown in FIG. 7, the positioning device 3 is driven and the nut portion 31 is moved along the ball screw 30 (step S2 in FIG. 4). Further, the air inside the cylinder body 400 of the side clamp cylinder device 40 starts to be released into the atmosphere. When the nut portion 31 is moved, the slave clamp 2a moves in the direction approaching the reference clamp 2b via the piston rod 401.

  By the way, when the movement of the sub clamp 2a is started, a force larger than the frictional resistance of the seal of the cylinder body 400 is required. That is, the air pressure in the cylinder body 400 needs to have a predetermined pressure. On the other hand, after the dependent clamp 2a starts to move once, the air pressure in the cylinder body 400 may not be as high as the predetermined pressure. For this reason, you may leak the air of the cylinder main body 400 until it becomes a pressure required in order to move the subordinate clamp 2a. In this way, the impact at the time of collision between the circuit board B and the subordinate clamp 2a can be further alleviated.

  When the slave clamp 2a moves in the direction approaching the reference clamp 2b, the circuit board B is pushed by the slave clamp 2a and is shifted to the reference clamp 2b side. The circuit board B after being offset is sandwiched between the subordinate clamp 2a and the reference clamp 2b. That is, the slave clamp 2a, the circuit board B, and the reference clamp 2b are connected to each other in the front-rear direction.

  In the decompression step, as shown in FIG. 8, even after the positioning device 3 is stopped, the air inside the cylinder body 400 continues to be released to the atmosphere (step S3 in FIG. 4). For this reason, although the dependent clamp 2a, the circuit board B, and the reference | standard clamp 2b are maintaining the connection state, the clamping force added to the circuit board B becomes very small.

  In the first surface aligning step, as shown in FIG. 9, the upper surface of the slave clamp 2a and the rear of the circuit board B are raised by raising the table body 600 of the first table 60 and the second table 61 shown in FIG. The upper surface of the edge is abutted against the lower surface of the claw portion 51a of the edge clamp 5a. In addition, the upper surface of the reference clamp 2b and the upper surface of the front edge of the circuit board B are abutted against the lower surface of the claw portion 51b of the edge clamp 5b (Steps S4 and S5 in FIG. 4). Then, the upper surface of the dependent clamp 2a, the upper surface of the circuit board B, and the upper surface of the reference clamp 2b are substantially flush with each other.

  In the protrusion allowance securing step, as shown in FIG. 10, the positioning device 3 is driven again, and the nut portion 31 is moved along the ball screw 30 (step S6 in FIG. 4). Here, the air inside the cylinder main body 400 of the side clamp cylinder device 40 remains released to the atmosphere. For this reason, the driving force is not transmitted from the nut portion 31 to the dependent clamp 2a. Therefore, the dependent clamp 2a does not move. Therefore, the nut portion 31 is close to the slave clamp 2a by the amount that the nut portion 31 is driven. When the nut portion 31 comes close to the subordinate clamp 2a, the piston rod 401 is relatively immersed in the cylinder body 400.

  In this clamping process, as shown in FIG. 11, air is supplied into the cylinder body 400 of the side clamping cylinder device 40 (step S7 in FIG. 4). Then, the slave clamp 2a is driven. The circuit board B is sandwiched and fixed between the slave clamp 2a and the reference clamp 2b. In this clamping process, the positioning device 3 remains stopped.

  In the separation step, as shown in FIG. 12, the subordinate clamp 2a, the circuit board B, and the reference clamp 2b are once lowered (step S8 in FIG. 4), so that the upper surface of the subordinate clamp 2a and the upper surface of the trailing edge of the circuit board B Is separated from the lower surface of the claw portion 51a of the edge clamp 5a. In addition, the upper surface of the reference clamp 2b and the upper surface of the front edge of the circuit board B are separated from the lower surface of the claw portion 51b of the edge clamp 5b.

  In the edge clamp retracting step, as shown in FIG. 13, the edge clamp 5a is retracted to a position where it does not interfere with the subordinate clamp 2a, and the edge clamp 5b is retracted to a position where it does not interfere with the reference clamp 2b (step S9 in FIG. 4). ).

  In the second surface alignment step, as shown in FIG. 14, the subordinate clamp 2a, the circuit board B, and the reference clamp 2b are raised again between the claw portions 51a and 51b (step S10 in FIG. 4). Then, the upper surfaces of the claw portions 51a and 51b, the upper surface of the dependent clamp 2a, the upper surface of the circuit board B, and the upper surface of the reference clamp 2b are substantially flush.

  Thereafter, a positional shift between the circuit board B and a screen mask (not shown) disposed above the circuit board B is detected by a camera unit (not shown). The positional deviation is adjusted by moving the third table 62 shown in FIG. After the misalignment adjustment, cream solder is printed on the circuit board B through the pattern hole of the screen mask by a squeegee device (not shown). The printed circuit board B is lowered to a predetermined height and then carried out by the pair of belt conveyors 7a and 7b. An electronic component is mounted on the unloaded circuit board B, and reflow soldering is performed.

[Function and effect]
Next, the effect of the circuit board clamping method and the screen printing machine according to the present embodiment will be described.

  According to the circuit board clamping method of the present embodiment, the pressure reducing step (see FIG. 8) is performed after the temporary clamping step (see FIG. 7). For this reason, even if the circuit board B is bent due to the clamping force in the temporary clamping process, the elastic restoring force of the circuit board B itself relatively exceeds the reduced clamping force in the decompression process. Thus, it is possible to suppress the bending from remaining on the circuit board B. Also, the temporary clamping process itself is performed while leaking air from the cylinder body 400. Also in this respect, it is possible to suppress the bending from remaining on the circuit board B.

  Further, according to the circuit board clamping method of the present embodiment, the slave clamp 2a is not driven using the nut portion 31 in the decompression step (see FIG. 8). For this reason, the connected state of the subordinate clamp 2a, the circuit board B, and the reference clamp 2b remains substantially maintained. Therefore, there is little possibility that a gap W1 as shown in FIGS. 20 and 21 is generated between the subordinate clamp 2a and the circuit board B. Therefore, in the present clamping step (see FIG. 11 above), when the slave clamp 2a is driven, the impact that the slave clamp 2a gives to the circuit board B is small.

  Further, the circuit board clamping method of the present embodiment includes a protrusion allowance securing step (see FIG. 10). For this reason, the protrusion margin of the piston rod 401 can be recovered. In the protrusion allowance securing step, the nut portion 31 is brought close to the dependent clamp 2a while suppressing an increase in the air pressure of the cylinder body 400. For this reason, the piston rod 401 is relatively immersed in the cylinder body 400. By the immersion operation, it is possible to secure the allowance for the piston rod 401 in the main clamping step (see FIG. 11 above). Moreover, in order to make the nut part 31 approach to the subordinate clamp 2a while suppressing an increase in the air pressure of the cylinder body 400, it is possible to suppress an increase in the pressing force applied to the circuit board B from the subordinate clamp 2a. it can.

  Further, the circuit board clamping method of the present embodiment includes a first surface alignment step (see FIG. 9). In the first surface aligning step, the upper surface of the subordinate clamp 2a, the upper surface of the circuit board B, and the upper surface of the reference clamp 2b are substantially flush. For this reason, the cream solder can be easily printed on the circuit board B.

  In the first surface alignment step (see FIG. 9 above), the surface alignment is performed while maintaining the substantially connected state. For this reason, at the time of surface alignment, the circuit board B and at least one of the reference clamp 2b and the dependent clamp 2a are in sliding contact with each other. Therefore, if the sliding resistance is large, smooth surface alignment becomes difficult.

  However, a decompression step (see FIG. 8 above) is set before the first surface alignment step. In the decompression step, the clamping force with respect to the circuit board B is reduced by lowering the air pressure of the cylinder body 400. For this reason, according to the circuit board clamping method of this embodiment, the sliding resistance between the circuit board B, the reference clamp 2b, and the subordinate clamp 2a is small. Therefore, the first surface alignment process can be performed smoothly.

  In addition, according to the circuit board clamping method of the present embodiment, the upper surface of the circuit board B, the upper surface of the reference clamp 2b, and the upper surface of the subordinate clamp 2a are obtained using the lower surfaces of the pair of edge clamps 5a and 5b. They are arranged substantially flush with each other. For this reason, the surfaces can be easily aligned.

  Further, the circuit board clamping method of the present embodiment includes a second surface alignment step (see FIG. 14). In the second surface aligning step, the upper surfaces of the pair of edge clamps 5a and 5b are also substantially flush with the upper surface of the dependent clamp 2a, the upper surface of the circuit board B, and the upper surface of the reference clamp 2b. For this reason, when cream solder is printed on the upper surface of the circuit board B, the pair of edge clamps 5a and 5b can be prevented from interfering with, for example, a screen mask.

  Further, according to the conventional screen printing machine 100 shown in FIGS. 17 to 23, the edge clamp cylinder device is mounted on the slave clamp 101a. For this reason, when the edge clamp 104a is retracted (see FIG. 20 above), the reaction force may be applied to the circuit board B1 via the dependent clamp 101a.

  On the other hand, according to the screen printing machine 1 of the present embodiment, the edge clamp cylinder device 41a is attached to the bracket 311 instead of the slave clamp 2a. Therefore, when the edge clamp 5a is retracted (see FIG. 13), the reaction force is less likely to be applied to the circuit board B via the dependent clamp 2a.

  Further, according to the conventional screen printing machine 100, when the slave clamp 101a is driven by the cylinder device 103, the edge clamp 104a becomes a weight. In other words, the cylinder device 103 needs to move not only the subordinate clamp 101a but also the edge clamp 104a. For this reason, when driving the dependent clamp 101a, the cylinder device 103 needs a relatively high air pressure (for example, 0.2 MPa or more).

  On the other hand, according to the screen printing machine 1 of the present embodiment, the edge clamp cylinder device 41a is attached to the bracket 311 instead of the slave clamp 2a. For this reason, when driving the side clamp cylinder device 40, the edge clamp 5a does not become a weight. Accordingly, the side clamp cylinder device 40 can move the sub clamp 2a even at a relatively low air pressure (for example, 0.07 MPa or more). In other words, according to the screen printing machine 1 of this embodiment, the control range of the air pressure of the side clamp cylinder device 40 can be expanded. That is, the control range of the clamping force can be expanded.

<Second embodiment>
The difference between the circuit board clamping method of the present embodiment and the circuit board clamping method of the first embodiment is that the protrusion allowance securing step is not executed. Further, the separation step is executed in parallel with the present clamping step. Therefore, only the differences will be described here.

  FIG. 15 shows a timing chart of the circuit board clamping method of this embodiment. In addition, about the site | part corresponding to FIG. 4, it shows with the same code | symbol. As shown in FIG. 15, the circuit board clamping method of the present embodiment includes an edge clamp entry step (step S <b> 1), a temporary clamp step (step S <b> 2), a pressure reduction step (step S <b> 3), and a first surface alignment step. (Steps S4 and S5), a main clamping step (Steps S11 and S12), a separation step (Step S8), an edge clamp withdrawal step (Step S9), and a second surface alignment step (Step S10). is doing.

  That is, according to the circuit board clamping method of the present embodiment, the clamping process is started immediately after the first surface alignment process without going through the protrusion allowance securing process. In this clamping process, first, the air pressure of the cylinder device (specifically, the side clamping cylinder device 40 in FIG. 5) is increased (step S11), and then the positioning device (specifically, in FIG. 5). Is driven (step S12), and the circuit board is clamped and fixed. Further, the separation step (step S8) is performed in parallel with the latter half of the clamping step using the positioning device (step S12).

  The circuit board clamping method and the screen printing machine of the present embodiment have the same operational effects as the circuit board clamping method and the screen printing machine of the first embodiment with respect to the parts having the same configuration. Further, according to the circuit board clamping method of the present embodiment, the separation step (step S8) and the latter half of the clamping step (step S12) can be performed in parallel. For this reason, the tact time can be shortened.

<Others>
The circuit board clamping method and the screen printing machine according to the present invention have been described above. However, the embodiment is not particularly limited to the above embodiment. Various modifications and improvements that can be made by those skilled in the art are also possible.

  For example, the fluid used for the side clamp cylinder device 40 and the edge clamp cylinder devices 41a and 41b is not particularly limited. Gases other than air, liquids such as water and oil, and the like can be used.

  In the above embodiment, the upper surface of the circuit board B, the upper surface of the reference clamp 2b, and the upper surface of the subordinate clamp 2a are arranged substantially flush with each other. Good. Further, the temporary clamping step may be performed with a predetermined pressure (pressure sufficient to start the movement of the subordinate clamp 2a) without leaking air from the cylinder body 400. This simplifies the sequence.

It is a side view of the screen printer of a first embodiment. It is a perspective view of the upper part of the movable part of the screen printing machine. It is a disassembled perspective view of the upper part of the movable part of the screen printing machine. It is a timing chart of the clamping method of the circuit board of a first embodiment. It is a schematic diagram of the screen printing machine of 1st embodiment. It is a schematic diagram in the edge clamp approach process of the screen printing machine. It is a schematic diagram in the temporary clamp process of the screen printing machine. It is a schematic diagram in the pressure reduction process of the screen printing machine. It is a schematic diagram in the 1st surface alignment process of the screen printing machine. It is a schematic diagram in the protrusion margin ensuring process of the screen printing machine. It is a schematic diagram in the main clamping process of the screen printing machine. It is a schematic diagram in the separation process of the screen printing machine. It is a schematic diagram in the edge clamp withdrawal process of the screen printing machine. It is a schematic diagram in the 2nd surface alignment process of the screen printing machine. It is a timing chart of the clamping method of the circuit board of a second embodiment. It is a timing chart of the clamping method of the circuit board in the conventional screen printer. It is a schematic diagram of the screen printing machine. It is a schematic diagram in the edge clamp approach process of the screen printing machine. It is a schematic diagram in the temporary clamp process of the screen printing machine. It is a schematic diagram in the side clamp withdrawal process of the screen printing machine. It is a schematic diagram in the 1st surface alignment process of the screen printing machine. It is a schematic diagram in the main clamping process of the screen printing machine. It is a schematic diagram in the 2nd surface alignment process of the screen printing machine.

Explanation of symbols

1: Screen printer.
2: side clamp device, 2a: slave clamp, 2b: reference clamp.
3: positioning device, 30: ball screw (guide part), 31: nut part (guided part), 310: nut body, 311: bracket.
40: cylinder device for side clamp (cylinder device), 41a: cylinder device for edge clamp, 41b: cylinder device for edge clamp, 400: cylinder body, 401: piston rod, 410a: cylinder body, 410b: cylinder body, 411a: Piston rod, 411b: Piston rod.
5: Edge clamp device, 5a: Edge clamp, 5b: Edge clamp, 50a: Base, 50b: Base, 51a: Claw, 51b: Claw, 52a: Spring, 52b: Spring.
60: First table, 61: Second table, 62: Third table, 600: Table body, 601: Lifting member, 602: Nut, 603: Ball screw, 604: Motor, 605: Guide rod, 610: Roller 620: Ball bearing, 621: Guide rail for cam, 622: Cam member, 623: Guide rail for edge clamp.
7: conveyor device, 7a: belt conveyor, 7b: belt conveyor, 70a: belt, 70b: belt.
8: Movable part.
9: support part, 90: lifting table, 91: support, 92: lifting device, 900: flat frame part, 901: guided column, 902: guided recess, 903: nut part, 910: guide rail, 920: motor , 921: Ball screw.

Claims (6)

A side having a reference clamp and a dependent clamp disposed at a predetermined interval with respect to the reference clamp, wherein the opposing side edges of the circuit board can be sandwiched from the side by the reference clamp and the dependent clamp. A clamping device;
A positioning device having a guide portion extending in the juxtaposition direction of both clamps in which the reference clamp and the dependent clamp are aligned, and a guided portion that moves along the guide portion;
A cylinder body, and a piston rod inserted into the cylinder body, the piston rod being reciprocated by the pressure of fluid inside the cylinder body. A cylinder device,
With
A method of clamping a circuit board in a screen printer capable of changing a distance between the reference clamp and the subordinate clamp by moving at least one of the guided portion and the piston rod,
By moving the guided portion while keeping the fluid pressure of the cylinder body at a predetermined pressure or lowering the fluid pressure, the slave clamp is brought close to the reference clamp, and the slave clamp And a temporary clamping step of shifting the circuit board to the reference clamp side until the circuit board and the reference clamp are connected to each other in the juxtaposed direction.
Reducing the pressure of the fluid in the cylinder body while maintaining the connected state, thereby suppressing the residual bending of the circuit board due to the biasing; and
A main clamping step of pressing the slave clamp by increasing the pressure of the fluid in the cylinder body in the substantially connected state and clamping the circuit board between the reference clamp and the slave clamp;
A method for clamping a circuit board.   Further, after the pressure reducing step or in parallel with the pressure reducing step, the guided portion is further moved by further moving the guided portion while suppressing an increase in the pressure of the fluid in the cylinder body. 2. The circuit board according to claim 1, further comprising a protrusion allowance securing step of bringing the piston rod close to the slave clamp, relatively immersing the piston rod in the cylinder body, and securing a protrusion allowance of the piston rod in the main clamp step. Clamping method.   Further, after the decompression step and before the main clamping step, the upper surface of the circuit board, the upper surface of the reference clamp, and the upper surface of the subordinate clamp are substantially faced to each other in the substantially connected state. 3. The circuit board clamping method according to claim 1, further comprising an upper surface arranging step of arranging the upper surface of the circuit board so that the upper surface of the circuit board protrudes relatively. The screen printing machine further includes an edge clamp device having a pair of edge clamps disposed outside the side clamp devices in the side-by-side direction of both clamps and capable of entering inside the side-by-side clamp direction,
Furthermore, before the upper surface arrangement step, there is an edge clamp entry step for allowing the pair of edge clamps to enter just above the opposite side edges of the circuit board,
In the upper surface arranging step, the upper surface of the both side edges of the circuit board, the upper surface of the reference clamp, and the upper surface of the subordinate clamp are brought into contact with the pair of edge clamps after entering from below. 4. The circuit board clamping method according to claim 3, which is a first surface alignment step in which the upper surface of the circuit substrate, the upper surface of the reference clamp, and the upper surface of the dependent clamp are arranged substantially flush with each other. Furthermore, after the main clamping step or in parallel with the main clamping step, the pair of edge clamps, the circuit board, the reference clamp, and the subordinate clamp are relatively separated in the vertical direction. When,
An edge clamp exiting step of retracting the pair of edge clamps to a position where they do not interfere with the circuit board and the reference clamp and the dependent clamp;
In addition to the upper surface of the circuit board, the upper surface of the reference clamp, the upper surface of the dependent clamp, and the upper surfaces of the pair of edge clamps arranged substantially flush with each other, the upper surfaces of the pair of edge clamps are also arranged substantially flush. The circuit board clamping method according to claim 4, further comprising a two-surface alignment step. A side having a reference clamp and a dependent clamp disposed at a predetermined interval with respect to the reference clamp, wherein the opposing side edges of the circuit board can be sandwiched from the side by the reference clamp and the dependent clamp. A clamping device;
A positioning device having a guide portion extending in the juxtaposition direction of both clamps in which the reference clamp and the dependent clamp are aligned, and a guided portion that moves along the guide portion;
A cylinder body, and a piston rod inserted into the cylinder body, the piston rod being reciprocated by the pressure of fluid inside the cylinder body. A cylinder device,
With
A screen printing machine capable of changing a distance between the reference clamp and the subordinate clamp by moving at least one of the guided portion and the piston rod,
By moving the guided portion while keeping the fluid pressure of the cylinder body at a predetermined pressure or lowering the fluid pressure, the slave clamp is brought close to the reference clamp, and the slave clamp And until the circuit board and the reference clamp are connected in the juxtaposed direction of both the clamps, the circuit board is shifted to the reference clamp side,
In order to prevent the deflection from remaining on the circuit board due to the displacement, the pressure of the fluid in the cylinder body is reduced while the connection state is maintained,
The subordinate clamp is pressed by increasing the pressure of the fluid in the cylinder body in the substantially connected state, and the circuit board is sandwiched between the reference clamp and the subordinate clamp. Screen printing machine.

Images