JP4293487B2 - Screen printing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a screen printing apparatus that screen-prints a paste such as cream solder on a substrate.
[0002]
[Prior art]
Conventionally, a screen mask for screen printing (hereinafter abbreviated as “mask”) is placed on a substrate set on a printing stage, and paste such as cream solder, conductive paste, or resistance paste supplied on the mask is expanded with a squeegee. In general, a screen printing apparatus that prints (applies) a paste to a predetermined position of a substrate through an opening formed in a mask is generally known.
[0003]
Such an apparatus normally includes a printing stage for placing a substrate, a carry-in conveyor for carrying the substrate to the printing stage, and a carry-out conveyor for carrying out the printed substrate.
[0004]
The printing stage has a mounting means for receiving the lower surface of the substrate loaded substantially horizontally, and a pair that can be opened and closed above the mounting means, and sandwiches the substrate placed on the placing means from both sides. And a clamp for causing the substrate to be overlaid. Here, because the clamped substrate is precisely mounted on the mask sheet, the upper surface of the clamp is flush with the upper surface (printed surface) of the substrate or slightly (for example, 0.1 mm) and the upper surface of the substrate is high. This state is preferable, and high positioning accuracy between the clamp and the substrate is required. On the other hand, if the substrate is bent, the positioning accuracy at the time of clamping tends to be impaired. Therefore, a pressing plate that presses the substrate between the clamp and the above-described mounting means is provided to temporarily hold the substrate on the mounting means while maintaining high positioning accuracy. And in order to pinch | interpose the board | substrate on a mounting means with a press plate, conventionally, the press plate was rotated in the range of 180 degrees with drive mechanisms, such as a rotary cylinder, and the clamp was straddled.
[0005]
[Problems to be solved by the invention]
In recent years, in the apparatus as described above, since the individual functional components are laid out in a relatively crowded state, when the pressing plate performs a pressing operation, a retraction operation is performed to avoid interference between the components. There was a need.
[0006]
For example, in the above-described apparatus, a fiducial mark provided on a substrate on a printing stage is used to accurately control the presence / absence of a substrate, the type of substrate, or the behavior of loading / unloading. Is required to be identified. However, this substrate recognition camera needs to be laid out at a position close to the substrate above the printing stage. On the other hand, in the conventional configuration in which the pressing plate rotates 180 °, the pressing plate is moved during the rotation. Since it stands up and protrudes largely upward, in order to avoid interference with this, the substrate recognition camera must be retracted from the rotation area of the pressing plate while the pressing plate is rotating. I had to. For this reason, in the conventional configuration, it is necessary to perform the pressing and releasing operation by the pressing plate and the operation of the substrate recognition camera in a time-shifted manner, which may increase the takt time and reduce the productivity. there were. On the other hand, it is possible to set a sufficient operation region in order to avoid interference with a functional component such as a board recognition camera. However, in this case, the entire apparatus becomes large, which is not preferable.
[0007]
The present invention has been made to solve the above-described problem, and contributes to downsizing, and performs a process of transferring a substrate carried in without interfering with a functional component operating directly above the mounting means. It is an object of the present invention to provide a screen printing apparatus that can handle the above problem.
[0008]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides a mounting means for receiving a lower surface of a substrate, a clamp that can be opened and closed above the mounting means, and sandwiches the substrate mounted on the mounting means from both sides. A pressing means for pressing the upper surface of the substrate to temporarily hold the substrate on the mounting means before being clamped by the clamp; and at least the substrate is temporarily held by the pressing means after being carried into the mounting means. A screen printing apparatus provided with a substrate recognition camera that moves the operating range of the pressing plate included in the pressing means when viewed in plan at the timing up to, wherein the pressing plate includes the substrate recognition camera and the substrate. wherein to avoid interference with the substrate recognition camera, is transmitted is converted into a driving force parallel motion force of the driving member for driving rotation from both ends to the pressure plate by moving the space between the And by, while maintaining a substantially horizontal state, those which are displaceably structure between a retracted position retracted outside the pressing position and the substrate to press the substrate (claim 1).
[0009]
In the present invention, when the substrate is delivered to the clamp, the pressing plate of the pressing means that temporarily holds the substrate is displaced while maintaining a substantially horizontal state. Therefore, the functional component that is operating directly above the mounting means. Therefore, the temporary holding operation of the substrate and the operation of the functional component can be performed in parallel. A typical example of the functional component is a substrate recognition camera for a substrate carried into a clamp when screen printing is performed on the substrate at the printing stage.
[0010]
In such an apparatus, in particular, the pressing plate is configured to translate by a parallel link (Claim 2).
[0011]
In the present invention, the pressing plate can be operated with a simple configuration.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
[0013]
1 is a schematic front view of an embodiment of a screen printing apparatus according to the present invention, FIG. 2 is a schematic side view of the screen printing apparatus of FIG. 1, and FIG. 3 is a schematic plan view of the screen printing apparatus of FIG. As shown in these drawings, on the base 2 of the screen printing apparatus 1, a carry-in conveyor 2a and a carry-out conveyor 2b for carrying in and carrying out a printed board W sandwich a printing stage 3 described later in detail. It is arrange | positioned at both sides (the left-right direction of FIG. 2, "X-axis direction" in this embodiment). Above the printing stage 3, a sheet holding unit 53 (see FIG. 2) for stretching a mask sheet 51 of a screen mask 50 superimposed on the printed circuit board W, as in a known apparatus, and a held mask And a squeegee unit 60 (see FIG. 1) disposed above the sheet 51. As will be described later, the squeegee of the squeegee unit 60 with respect to the printed circuit board W superimposed on the mask sheet 51 by the printing stage 3. 61 is used for screen printing.
[0014]
As shown in FIG. 1, a substrate recognition camera 70 (an example of a functional component) that is conveyed by a ball screw mechanism (not shown) is provided at a fixed position of the base 2 and is carried in from the carry-in conveyor 2a. The substrate recognition operation for identifying the fiducial mark marked on the printed board W at a predetermined timing is performed, so that the presence / absence of the board W and the product number can be identified. As shown by the area A in FIG. 3, the operation range of the board recognition camera 70 is included in the operation range of the pressing plate 31 included in the pressing means 30 described later on the plane.
[0015]
As shown in FIGS. 1 and 2, the printing stage 3 includes a fixed table 4 installed at a fixed position of the base 2 and a pair of rails 5 and a ball screw unit 15 with respect to the fixed table 4. 1, a Y-axis table 6 that can be relatively displaced in the left-right direction (“Y-axis direction” in this embodiment), and the X-axis direction with respect to the Y-axis table 6 via a pair of rails 7 and a ball screw unit 17. An X-axis table 8 that is relatively displaceable, and an R-axis table 10 that is rotatable around a vertical line (in this embodiment, “Z-axis direction”) via a rotation unit 9 provided on the X-axis table 8. The R-axis table 10 includes a lifting table 12 that can be moved up and down relatively via a ball screw unit 11 (shown only in FIG. 2). A clamp unit 20 is attached to the lifting table 12. The ball screw units 11, 15, 17 and the rotation unit 9 are each driven by a servo motor.
[0016]
As shown in FIG. 1, the clamp unit 20 is provided in a pair with a pair of fixed pillars 21 standing on one end side in the Y-axis direction of the lifting table 12 and arranged in the X-axis direction. It has a movable pillar 23 that can be moved relative to the lifting table 12 in the Y-axis direction via a ball screw unit 22, and clamp pieces 24 a and 24 b that are provided on the pillars 21 and 23 and make a pair. Each clamp piece 24a, 24b is a substantially plate-like member extending in the X-axis direction (see FIGS. 3 to 5), and is relatively displaced along the Y-axis direction by the displacement of the movable pillar 23, so that the carry-in conveyor A clamp 24 is configured to sandwich the printed circuit board W carried in from 2a. The ball screw unit 22 is driven by a servo motor via a belt transmission mechanism.
[0017]
A pin unit 25 as a mounting means is provided between the clamp pieces 24a and 24b. Although not shown, the pin unit 25 is configured to be able to be displaced in the Y-axis direction following the movable pillar 23 and to be vertically movable relative to the pillars 21 and 23. ing. Thereby, when the printed board W is carried in between the clamp pieces 24a and 24b from the carry-in conveyor 2a, the lower surface is received by the pin 25a of the pin unit 25, and the printed board W can be temporarily placed. ing.
[0018]
And in this embodiment, the press means 30 which delivers to the clamp 24 in the state which positioned the printed circuit board W precisely by temporarily hold | maintaining the printed circuit board W temporarily placed in the pin unit 25 is provided.
[0019]
4 and 5 are perspective views showing the main part of the printing stage according to the embodiment of FIG. 1, FIG. 4 shows the clamp release state, and FIG. 5 shows the clamp state.
[0020]
Referring to FIGS. 1, 3, 4, and 5, pressing means 30 includes pressing plates 31 and 32 that are arranged in parallel to the clamp pieces 24 a and 24 b. Each of the pressing plates 31 and 32 is driven by a pair of driving members (rotary cylinders in the present embodiment) 33 and 34 provided at both ends in the longitudinal direction. The drive members 33 and 34 are attached to the pillars 21 and 23 of the printing stage 3 via attachment frames (not shown). Here, in the present embodiment, two pairs of parallel links 35 and 36 are provided in order to transmit the power of the drive members 33 and 34 to the corresponding pressing plates 31 and 32. These parallel links 35 and 36 convert the rotational driving force of the corresponding driving members 33 and 34 into the kinetic force parallel to the Y-axis direction, and the driving members 33 and 34 are connected via the parallel links 35 and 36. As shown in FIG. 4, each of the pressing plates 31 and 32 is retracted to the outside of the corresponding clamp pieces 24a and 24b in the Y-axis direction. As shown in FIG. 5, the retracted position is moved above the corresponding clamp pieces 24 a and 24 b, and the opposite edges 31 a and 32 a are displaced between the pressed positions where the printed board W on the pin unit is pressed. It is configured to be possible.
[0021]
Specifically, each of the pressing plates 31 and 32 is configured by a sheet metal member bent in a substantially L shape, and the longitudinal direction thereof extends along the X-axis direction. And, one end of the parallel link 35A (36A) on the driving side and the parallel link 35B (36B) on the driven side are connected in pairs as a pair via a bracket (not shown).
[0022]
The drive-side parallel link 35A (36A) is connected to the corresponding drive member 33 (34) at the other end so that power can be transmitted to the pressing plates 31, 32, and the driven-side parallel link. The other end of 35B (36B) is connected to the mounting frame holding the drive member 33 (34), cooperates with the parallel link 35a (36A) on the drive side, and the drive member 33 (34). It is configured to convert the power and move the pressing plates 31 and 32 in parallel.
[0023]
As shown in FIG. 4, the pressing plates 31 and 32 are set so as to be slightly lower than the upper surfaces of the clamp pieces 24a and 24B in the retracted position, so that the pressing plates 31 and 32 are screen mask 50 during screen printing. Consideration is made so as not to interfere with the other mask sheet 51. Further, notches N for avoiding interference with the parallel links 35 and 36 of the pressing plates 31 and 32 are provided at both longitudinal ends of the clamp pieces 24a and 24b. The effective pressing length L (FIG. 3) of the pressing plates 31 and 32 is set to be wide.
[0024]
Next, the substrate transfer operation according to the present embodiment will be described with reference to FIGS. 6 and 7. 6 and 7 are operation procedure diagrams schematically showing the clamping operation of the printing stage 3 according to the embodiment of FIG.
[0025]
First, referring to FIG. 6A, in the initial state, the movable-side clamp piece 24b is separated from the fixed-side clamp piece 24a by some distance (printing necessary and sufficient to hold the printed board W). The distance is slightly larger than the width of the substrate W). Further, the pressing plates 31 and 32 take retreat positions for retreating behind the corresponding clamp pieces 24a and 24b by corresponding drive members 33 and 34 (see FIGS. 4 and 5).
[0026]
From this state, the printed circuit board W is conveyed above the pin unit 25 by the carry-in conveyor 2a. On the other hand, each pin 25a of the pin unit 25 rises at a timing until the printed circuit board W reaches above the pin unit 25, and is displaced to a position where the lower surface of the printed circuit board W can be received.
[0027]
Referring to FIG. 6B, when printed board W is transported from the initial state, printed board W is placed on raised pins 25a. In the process up to FIG. 6B, the board recognition camera 70 moves in the above-described region A (FIG. 3), is displaced to a position where the printed board W can be recognized, and is marked on the printed board W. Imaging fiducial marks.
[0028]
Next, with reference to FIG.6 (C), in this embodiment, each press board 31 and 32 is driven, and is displaced to a press position as shown in the figure. This substrate pressing operation is performed based on the fact that a control means (not shown) has identified that a regular printed circuit board W has been carried in as expected.
[0029]
With reference to FIG. 7A, when the sandwiching operation of the printed board W by the pressing means 30 is completed, the printed board W is temporarily held with respect to the clamp 24 so as to be delivered in a precisely aligned state. . In this state, the movable pillar 23 is driven as illustrated.
[0030]
As shown in FIG. 7C, when the printed circuit board W is sandwiched between the clamp pieces 24a and 24b that have shifted to the sandwiching operation, the pressing plates 31 and 32 are now displaced to the retracted position. At this time, a fiducial mark is imaged by the board recognition camera 70, the printed board W is detected, and position correction is performed based thereon. Therefore, the operation of moving the board recognition camera 70 onto the printed board W can be performed at a stage prior to this point (stages from FIG. 6A to FIG. 7C). As a result, in this embodiment, it is possible to reduce the tact time. Thereafter, the lifting table 12 (see FIG. 1) of the printing stage 3 is raised, and the clamped printed circuit board W is transported to the lower surface of the mask sheet 51 stretched in advance, and the printed circuit board W is overlapped with the mask sheet 51. Disguise.
[0031]
Thereafter, as shown in FIG. 7D, the squeegee 61 of the squeegee unit 60 is lowered and screen printing is performed as in the conventional case.
[0032]
As described above, in the above-described embodiment, when the printed circuit board W is delivered to the clamp 24, the pressing plates 31 and 32 of the pressing means 30 that temporarily holds the printed circuit board W recognize the moving board. Since the displacement is made through a path that can avoid the interference with the camera 70, the temporary holding operation of the printed circuit board W and the operation of the substrate recognition camera 70 can be performed in parallel.
[0033]
Therefore, in this embodiment, the delivery process of the printed board W carried in is performed in parallel with the operation of the board recognition camera 70, and a significant effect is obtained that the loss of tact time can be eliminated.
[0034]
In particular, in this embodiment, since the pressing plates 31 and 32 of the pressing means 30 are translated using the parallel links 35 and 36, the pressing plates 31 and 32 of the pressing means 30 are operated with a simple configuration. Therefore, there is an advantage that it can be carried out at a low cost.
[0035]
【The invention's effect】
As described above, according to the present invention, when the substrate is delivered to the clamp, the temporary holding operation of the substrate and the operation of the functional component can be performed in parallel, which contributes to downsizing. In addition, there is a remarkable effect that it is possible to perform the process of transferring the substrate that has been carried in without retracting the functional parts.
[0036]
In particular, when the pressing means for temporarily holding the substrate is a plate-like member that is moved in parallel by a parallel link, it is possible to operate with a simple configuration, so that the cost can be kept low. There is an advantage that can be.
[Brief description of the drawings]
FIG. 1 is a schematic front view of an embodiment of a screen printing apparatus according to the present invention.
FIG. 2 is a schematic side view of the screen printing apparatus of FIG. 1;
FIG. 3 is a schematic plan view of the screen printing apparatus of FIG. 1;
4 is a perspective view showing a main part of the printing stage according to the embodiment of FIG. 1 in a clamp release state.
FIG. 5 is a perspective view showing a main part of the printing stage according to the embodiment of FIG. 1 in a clamped state.
6 is an operation procedure diagram schematically showing a clamping operation of the printing stage according to the embodiment of FIG. 1. FIG.
FIG. 7 is an operation procedure diagram schematically showing a clamping operation of the printing stage according to the embodiment of FIG. 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Screen printing apparatus 2 Base 2a Carry-in conveyor 2b Carry-out conveyor 3 Printing stage 20 Clamp unit 21 Fixed pillar 23 Movable pillar 24 Clamp 24a Clamp piece 24b Clamp piece 25 Pin unit (mounting means)
30 Pressing means 31 Pressing plate 33 Driving member 35 Parallel link 70 Board recognition camera (an example of a functional component)
W Printed circuit board

Claims (2)

A mounting means for receiving the lower surface of the substrate, a pair that can be opened and closed above the mounting means, and a clamp that sandwiches the substrate placed on the placing means from both sides, and on the placing means before the clamping by the clamp Pressing means for pressing the upper surface of the substrate in order to temporarily hold the substrate, and at least a timing from when the substrate is carried into the mounting means until it is temporarily held by the pressing means, as viewed in a plan view. A substrate recognition camera that moves an operating range of the pressing plate included in the screen, wherein the pressing plate moves in a space between the substrate recognition camera and the substrate to recognize the substrate. so as to avoid interference with the camera, the driving force of the drive member for driving rotation is transmitted to the pressing plate from both ends being converted to parallel movement force, while maintaining a substantially horizontal state, group Screen printing apparatus characterized by being displaceable configured between a retracted position retracted outside the pressing position and the substrate for pressing the.   2. The screen printing apparatus according to claim 1, wherein the pressing plate is configured to move in parallel by a parallel link.

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