JP2008168442A - Screen printing equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide screen equipment, the holding properties of a board of which is improved. <P>SOLUTION: By constituting one clamping plate 4b between a pair of clamping plates 4a and 4b arranged on both the side faces of the board 3 changeably in posture, the clamping plate 4b displaces to a posture planarly contacting with one side face 3b of the board 3 during a process moving to a direction approaching to the other clamping plate 4a, resulting in pinching the board 3 in the state that the posturally displaced clamping plate 4b and the clamping plate 4a planarly contact with both the side faces 3b and 3a of the board 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a screen printing apparatus.

In the field of electronic component mounting, screen printing apparatuses that print cream solder on the printed surface of a substrate are widely used. The screen printing apparatus is an apparatus for masking the printed surface of a substrate with a mask provided with an arbitrary pattern hole, and pattern printing the cream solder spread on the mask on the printed surface through the pattern hole. This screen printing apparatus is provided with a clamp mechanism for holding a substrate to be printed. The holding of the substrate by the clamp mechanism is such that either one or both of the pair of clamp plates arranged on both sides of the substrate are movable and kept close to each other, and one of them is pushed to one side of the substrate. In general, the contact is made while the other is pressed against the other side of the substrate and the substrate is sandwiched from both sides (see Patent Document 1).
JP 2006-289676 A

  In order to securely hold the substrate with such a clamp mechanism, it is necessary to make the clamp plate come into surface contact with the side surface of the substrate accurately, but the substrate produced in response to a recent cost reduction request has dimensional accuracy. Since there are many cases where there is a variation in both, and there are cases where the parallelism on both sides exceeds the allowable value, there is a situation where the conventional clamping mechanism cannot be held in precise surface contact. The substrate held in such an unstable state is such that the portion that is not in contact with the clamp plate is inclined to the mask side due to the viscosity of the cream solder when the plate is released after printing, and printing such as misalignment or peeling of the printed portion The probability that a defect will occur is high.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a screen printing apparatus with improved substrate retention.

  The screen printing apparatus according to claim 1, further comprising: a clamp mechanism that clamps the substrate from both sides; and a mask that masks a printed surface of the substrate sandwiched by the clamp mechanism, through a pattern hole provided in the mask. A screen printing apparatus for pattern-printing a paste on a printed surface of a substrate, wherein the clamp mechanism includes a pair of clamp plates disposed on both sides of the substrate and at least one of the pair of clamp plates. A clamp plate moving means for moving the clamp plate in a direction in contact with and away from the other clamp plate, and at least one of the pair of clamp plates in the process of bringing the one clamp plate close to the other clamp plate. And a clamp plate posture displacement means for displacing to a posture in contact with the side surface.

  A screen printing apparatus according to a second aspect is the screen printing apparatus according to the first aspect, wherein the clamp plate posture displacing means is at a base portion that moves integrally with the clamp plate, and at a substantially center of the clamp plate. Pivot means for pivotally supporting the clamp plate on the base so as to be rotatable in a plane parallel to the printing surface of the substrate.

  A screen printing apparatus according to a third aspect is the screen printing apparatus according to the second aspect, further comprising urging means for urging the clamp plate against the base.

The screen printing apparatus according to claim 4 is the screen printing apparatus according to claim 2 or 3, wherein the clamp plate is regulated to a predetermined posture in a process of separating the clamp plate from the other clamp plate. Provided with means.

  According to the present invention, in the process of bringing at least one clamp plate out of the pair of clamp plates constituting the clamp mechanism into proximity to the other clamp plate, at least one clamp plate is displaced to a posture in contact with one side surface of the substrate. As a result, it is possible to hold the substrate in a state where both sides are in contact with each other, so that even a substrate with low manufacturing accuracy can be improved, and the occurrence rate of printing defects such as misalignment and peeling of the printed portion can be reduced. The printing quality in the screen printing apparatus can be stabilized.

  A screen printing apparatus according to an embodiment of the present invention will be described with reference to the drawings. 1 is a front view of a screen printing apparatus according to an embodiment of the present invention, FIG. 2 is a front view of the screen printing apparatus according to the embodiment of the present invention, and FIG. 3A is a diagram of a clamp mechanism according to the embodiment of the present invention. FIGS. 3B and 3C are side views of the clamp mechanism according to the embodiment of the present invention, and FIGS. 4A and 4B show the holding operation of the substrate by the clamp mechanism according to the embodiment of the present invention. FIG. 5 (a) is a front view of a clamp mechanism according to another embodiment of the present invention, FIG. 5 (b) is a side view of the clamp mechanism according to another embodiment of the present invention, and FIG. 6 (a). (B) is explanatory drawing which shows holding | maintenance operation | movement of the board | substrate by the clamp mechanism of other embodiment of this invention.

  First, the screen printing apparatus of this embodiment will be described. In FIG. 1, a screen printing apparatus 1 is an apparatus for pattern-printing a paste on the surface of a substrate 3 aligned with a mask 2 in which predetermined pattern holes 2a are formed. The screen printing apparatus 1 includes a holding unit 4 that holds the substrate 3 in a predetermined position, and an elevating unit that moves the substrate 3 held by the holding unit 4 up and down, and contacts and separates the printing surface 3 c of the substrate 3 from the back surface of the mask 2. 5, a support means 6 for supporting the substrate 3 from the back surface, a horizontal movement means 7 for horizontally moving the substrate 3 held by the holding means 4 and aligning the substrate 3 and the mask 2, and the substrate 3 and the mask 2 The image pickup means 8 for picking up an image of a position recognition mark (not shown) provided on the mask 2 and a squeegee unit 9 for filling the pattern hole 2a of the mask 2 with paste.

  The holding means 4 is configured by a clamp mechanism that clamps the substrate 3 conveyed along the pair of conveyance rails 10a and 10b from both sides, and the substrate 3 is moved by approaching or separating the pair of clamp plates 4a and 4b. Hold or release.

  The elevating means 5 is composed of a feed screw mechanism that elevates and lowers the clamp mechanism that constitutes the holding means 4, and masks the surface of the substrate 3 held by the clamp mechanism by switching the rotation of the feed screw 5a in the forward and reverse directions. 2. Contact with and away from the back of 2.

  The support means 6 is composed of a feed screw mechanism that raises and lowers the support block 6a that is in surface contact with the back surface of the substrate 3, and rotates the feed screw 6b to raise the support block 6a, thereby conveying the substrate 3 as a pair. Lift up from the rails 10a, 10b.

  The horizontal moving means 7 is configured by laminating an X table 7a, a Y table 7b, and a θ table 7c. The horizontal movement means 7 moves and rotates the substrate 3 held by the clamp mechanism in a horizontal plane, and moves the substrate 3 with respect to the fixed mask 2. Position the board and align them.

The image pickup unit 8 moves between the mask 2 and the substrate 3 and is provided with position recognition marks (not shown) provided on the mask 2 and the substrate 3 by two CCD cameras 8a and 8b arranged in the vertical direction. ). When the relative position between the mask 2 and the substrate 3 is recognized by the data processing of the captured image, and the displacement between the two is recognized, the horizontal position of the substrate 3 is corrected by the horizontal moving means 7.

  The squeegee unit 9 includes a pair of squeegees 9 a and 9 b, elevating mechanisms 9 c and 9 d that raise and lower each squeegee 9 a and 9 b independently, and a horizontal movement that horizontally moves the pair of squeegees 9 a and 9 b along the surface of the mask 2. It is comprised with the mechanism 9e.

  The screen printing apparatus 1 configured as described above performs screen printing as follows. In FIG. 2, the substrate 3 lifted up to a height where the printing surface 3a is at the same level as the surfaces of the clamp plates 4a and 4b is applied to the back surface of the mask 2 while being sandwiched by the clamp plates 4a and 4b from both sides. A squeegee 9a that contacts and slides on the surface of the mask 2 fills the pattern holes 2a with the paste P. When the paste P is filled in all the pattern holes 2a, the sliding of the squeegee 9a is stopped and the substrate 3 is lowered. As a result, the back surface of the mask 2 and the printing surface 3a of the substrate 3 are separated from each other, and the paste P filled in the pattern holes is printed on the printing surface 3a.

  The printed substrate 3 is unloaded from the screen printing apparatus 1, and a new substrate 3 is loaded instead. This new substrate 3 is also subjected to the same screen printing, but since the paste P is moved to one side of the mask 2 by the squeegee 9a, the squeegee 9b slides on the surface of the mask 2 instead of the squeegee 9a. Then, the paste P moved to one side by the squeegee 9a is filled in the pattern hole 2a while moving in the reverse direction along the surface of the mask 2. Thus, screen printing can be performed on the plurality of substrates 3 by sliding the squeegees 9 a and 9 b alternately on the surface of the mask 2 each time a new substrate 3 is carried.

  Next, the clamp mechanism will be described. 1 and 2, the holding means 4 is constituted by a clamp mechanism that moves one clamp plate 4b of the pair of clamp plates 4a and 4b closer to or away from the other clamp plate 4a. In FIG. 3, the clamp plate 4 b is attached to a base portion 21 whose movement is restricted in one direction along the guide 20, and the clamp plate 4 b is moved along the guide 20 by the actuator 22. It is configured to move in the direction of contact with and away from 4a (see arrow A). The clamp plate moving means comprising the guide 20, the base 21, and the actuator 22 may be provided not only on one clamp plate 4b but also on the other clamp plate 4a, but only one of them is moved in terms of positioning accuracy of the substrate 3. It is generally possible to make the other and the other fixed.

  A bearing 23 is provided at the center of the clamp plate 4b, and supports a support pin 24 fixed to the base 21. Further, on both sides of the clamp plate 4b across the bearing 23, a through hole 25 penetrating from the surface to the base portion 21 side is formed, and in this through hole 25, a spring 26 and a spring stopper pin 27 fixed to the base portion 21 are formed. Is stored. The spring 26 is disposed between the lower portion of the through hole 25 formed smaller than the diameter of the spring 26 and the upper portion of the spring stopper pin 27 formed larger than the diameter of the spring 26 so as not to separate the clamp plate 4 b from the base portion 21. It functions as an urging means for urging the base 21 side.

  Further, the lower portion of the through hole 25 is formed larger than the diameter of the spring retaining pin 27, and the upper portion of the spring retaining pin 27 is formed smaller than the diameter of the through hole 25. Is allowed, and the clamp plate 4b is rotatable around the support pin 24 (see arrow B). As a result, the relative angle between the pair of clamp plates 4a and 4b can be changed, and even in the case of the substrate 3 having low parallelism on both sides, surface contact is made with each of the pair of clamp plates 4a and 4b. It can be held in the state. The posture correction pin 28 functions as posture correction means for adjusting the posture of the clamp plate 4b to a posture substantially parallel to the clamp plate 4a in the process of separating the clamp plate 4b from the clamp plate 4a.

  In FIG. 4, when sandwiching a substrate 3 whose side surfaces 3a and 3b are not parallel, when the substrate 3 is disposed between the pair of clamp plates 4a and 4b, the clamp plate 4b is brought close to the clamp plate 4a (arrow C). In this process, the clamp plate 4b is displaced so that the clamp plate 4b comes into contact with one side surface 3b of the substrate 3 (refer to the rotation direction D), and the clamp plate 4a that comes into contact with the clamped plate 4b and the other side surface 3a. To hold the substrate 3 from both sides. Further, when the clamp plate 4b is moved away from the clamp plate 4a (see arrow E) in order to carry out the substrate 3 on which the screen printing has been completed, the clamp plate 4b comes into contact with the posture adjusting pin 28 in the process, and the clamp plate 4a The posture is displaced so as to be in a substantially parallel posture (see rotation direction F). In this way, by waiting for a new substrate to be loaded in a state in which the pair of clamp plates 4a and 4b are in a substantially parallel posture, the clamp plate 4b that has been displaced in correspondence with the side surface 3b of the previous substrate 3 This does not hinder the introduction of new substrates.

  In this way, by configuring one clamp plate 4b of the clamp mechanism to be rotatable around the support pin 24, even if the substrate 3 is not parallel on both sides, it can be held in a state of being in contact with both sides. Therefore, even if the substrate is low in manufacturing accuracy, the holding property is improved, and the substrate 3 is dragged by the viscosity of the paste when the substrate 3 is displaced with respect to the mask 2 during screen printing or when the plate is separated after printing. Occurrence of an accident that tilts or falls is suppressed. As a result, the occurrence rate of printing defects such as misalignment and peeling of the printed portions is reduced, and the printing quality in the screen printing apparatus can be stabilized.

  The bearing 23 and the support pin 24 function as pivot support means for pivotally supporting the clamp plate 4b on the base 21 so that the clamp plate 4b can rotate in a plane parallel to the printing surface of the substrate 3 at the approximate center of the clamp plate 4b. The clamp plate 4b functions as a clamp plate posture displacing means for displacing the clamp plate 4b into a posture in contact with one side surface 3b of the substrate 3 in the process of making the plate close to the clamp plate 4a. The bearing 23 is provided in order to smoothly rotate the clamp plate 4b, and is not an essential component as a means for pivotally supporting the clamp plate 4b around the support pin 24.

  In addition to the configuration in which the actuator 22 moves the base portion 21 indirectly as described above, the clamp mechanism indirectly moves the clamp plate 4b in the direction of contacting and separating from the clamp plate 4a, as shown in FIG. Alternatively, the clamp plate 4b may be moved. In FIG. 3, the actuator 22 is connected to the base 21 via an attachment 22a, and the attachment 22a serves as a transmission means for transmitting the drive of the actuator 22 to the base. On the other hand, in FIG. 5, the actuator 22 is connected to the clamp plate 4b via the attachment 22b, and the attachment 22a serves as a transmission means for directly transmitting the drive of the actuator 22 to the clamp plate 4b.

  As shown in FIG. 6, a clamp plate using a plurality of actuators 22 arranged at substantially equal intervals (in FIG. 6, actuators 22c and 2d are respectively arranged at two locations dividing the clamp plate 4b into approximately three equal parts). When 4b is moved toward the clamp plate 4a (see arrow G), the clamp plate 4b on the side where the actuator 22c is first placed comes into contact with one side surface 3b of the substrate 3, and the actuators 22c and 22d are driven as they are. If it continues, the clamp board 4b by which the actuator 22d is arrange | positioned will also adjoin the one side surface 3b of the board | substrate 3. FIG. As a result, the clamp plate 4b is displaced in a posture to be in contact with one side surface 3b of the substrate 3 (see the rotation direction H), and the substrate 3 is clamped by the posture-displaced clamp plate 4b and the clamp plate 4a in contact with the other side surface 3a. Is clamped from both sides.

When the clamp plate 4b is moved away from the clamp plate 4a to carry out the substrate 3 on which screen printing is completed (see arrow E), the actuator 22c first comes into contact with the posture setting pin 28a, and the actuators 22c, 22d If the driving is continued, the actuator 22d side then comes into contact with the posture regulating pin 28b, and the posture of the clamp plate 4b is displaced so as to be substantially parallel to the clamp plate 4a (see the rotation direction F).

  According to the present invention, in the process of bringing at least one clamp plate out of the pair of clamp plates constituting the clamp mechanism into proximity to the other clamp plate, at least one clamp plate is displaced to a posture in contact with one side surface of the substrate. Thus, it has an advantage that the substrate can be held in a state where both sides are in contact with each other, and is particularly useful in the field of screen printing which requires a stable print quality even if the substrate has low manufacturing accuracy.

Front view of a screen printing apparatus according to an embodiment of the present invention Front view of a screen printing apparatus according to an embodiment of the present invention (A) Front view of clamp mechanism of embodiment of this invention, (b) (c) Side view of clamp mechanism of embodiment of this invention (A) (b) Explanatory drawing which shows holding | maintenance operation | movement of the board | substrate by the clamp mechanism of embodiment of this invention. (A) Front view of clamp mechanism according to another embodiment of the present invention, (b) Side view of clamp mechanism according to another embodiment of the present invention (A) (b) Explanatory drawing which shows holding | maintenance operation | movement of the board | substrate by the clamp mechanism of other embodiment of this invention.

Explanation of symbols

2 mask 2a pattern hole 3 substrate 3a, 3b substrate side surface 3c substrate printing surface 4 clamp mechanism 4a, 4b clamp plate P paste 20 guide 21 base 22 actuator 23 bearing 24 support pin 26 spring 28 posture regulating pin

Claims (4)

A clamp mechanism for clamping the substrate from both sides, and a mask for masking the printing surface of the substrate held by the clamping mechanism, and pattern printing the paste on the printing surface of the substrate through a pattern hole provided in the mask A screen printing device,
The clamp mechanism is a pair of clamp plates disposed on both sides of the substrate, and a clamp plate moving means for moving at least one clamp plate of the pair of clamp plates in a direction of contacting and separating from the other clamp plate; Clamp plate posture displacement means for displacing at least one clamp plate of the pair of clamp plates to a posture in contact with one side surface of the substrate in the process of bringing the one clamp plate close to the other clamp plate. Printing device.   The clamp plate posture displacing means is pivotally supported by the base so that the clamp plate can be rotated in a plane parallel to the printing surface of the substrate at the approximate center of the clamp plate. The screen printing apparatus according to claim 1, wherein the screen printing apparatus is a pivoting means.   The screen printing apparatus according to claim 2, further comprising a biasing unit that biases the clamp plate against the base.   The screen printing apparatus according to claim 2, further comprising posture correcting means for correcting the clamp plate to a predetermined posture in a process of separating the clamp plate from the other clamp plate.

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