JP4238683B2 - Substrate detection method in electronic component mounting apparatus - Google Patents

Description

  The present invention relates to a substrate detection method in an electronic component mounting apparatus that detects the presence or absence of a substrate at a substrate stop position of a substrate transport mechanism in the electronic component mounting apparatus.

In an electronic component mounting apparatus such as an electronic component mounting apparatus or a screen printing apparatus, a substrate is positioned at a predetermined position while being moved by a substrate transport mechanism such as a conveyor. This positioning is performed by pressing the end of the substrate against a mechanically driven positioning stopper. Whether or not a substrate actually exists at the substrate stop position by this stopper is detected by a substrate detection sensor using a reflective optical sensor or the like, and a subsequent operation sequence proceeds based on this detection signal (for example, Patent Document 1).
JP 7-208920 A

  By the way, there are various types of substrates to be transported and positioned by the same apparatus, and the color and surface gloss of the detection target part of the substrate detection sensor may differ depending on the substrate. For this reason, the malfunction which the detection result by the above-mentioned board | substrate detection sensor was influenced by the color and surface property of the board | substrate had arisen. In spite of the presence of the substrate at a predetermined substrate stop position, a signal indicating no substrate is output, and as a result, a malfunction may occur due to erroneous detection of the substrate by the substrate detection sensor.

  Therefore, an object of the present invention is to provide a substrate detection method in an electronic component mounting apparatus that can prevent erroneous detection of a substrate by a substrate detection sensor.

The substrate detection method in the electronic component mounting apparatus of the present invention is the electronic component mounting apparatus used in the process of manufacturing the mounting substrate in which the electronic component is mounted on the substrate. A substrate detection method in an electronic component mounting apparatus for detecting, wherein a substrate stopper provided to be freely tiltable at the substrate stop position, a tilting mechanism for driving a tilting operation of the substrate stopper, and the tilting mechanism and a control unit for controlling the stopper standing step of the movable blocking state of the base plate in the substrate transfer mechanism by standing the substrate stopper projecting direction to the nearest position of the upstream side of the substrate stopper A detection preparation step for receiving a detection signal by a substrate detection sensor using a retroreflective optical sensor disposed toward the substrate transport level side, and The light irradiated from the light projecting portion of the substrate detection sensor in a state where it has not arrived at the plate stop position is reflected by the light receiving portion of the substrate detection sensor and is reflected by the reflecting portion provided at the end of the substrate stopper. Substrate non-detection step of detecting “no substrate”, and light emitted from the light projecting portion of the substrate detection sensor in a state where the substrate arrives at the substrate stop position and is prevented from moving by the substrate stopper Is detected by the substrate and the reflected light is not received by the light receiving unit, so that the presence of the substrate is detected, and the substrate stopper is lowered and the detection signal from the substrate detection sensor is not received. A detection stop step, and the control unit outputs a detection signal from the substrate detection sensor at a predetermined timing on the operation sequence. The control unit captures the detection signal of the substrate detection sensor only in a state where the substrate stopper is raised for the purpose of stopping the movement of the substrate by controlling the raising / lowering mechanism based on the detection signal. I did it.

  According to the present invention, as the substrate detection sensor, the retroreflective optical sensor configured to reflect the light from the light projecting unit by the reflecting unit and enter the light receiving unit is used, and the reflecting unit is provided at the end of the substrate stopper. The substrate detection processing is performed while controlling the reception / non-reception of the detection signal of the substrate detection sensor in synchronization with the operation of the substrate stopper 20, thereby ensuring erroneous detection of the substrate at the substrate stop position. Can be prevented.

  Next, embodiments of the present invention will be described with reference to the drawings. 1 is a side view of a screen printing apparatus according to an embodiment of the present invention, FIG. 2 is a plan view of the screen printing apparatus according to an embodiment of the present invention, and FIG. 3 is a screen printing apparatus according to an embodiment of the present invention. FIG. 4 is an explanatory view of a substrate detection method in the screen printing method of one embodiment of the present invention.

  First, the structure of the screen printing apparatus will be described with reference to FIGS. In FIG. 1, the substrate positioning unit 1 is configured by stacking Z-axis tables 4 on a moving table composed of a Y-axis table 2 and an X-axis table 3. The upper surface on the Z-axis table 4 serves as a lower receiving portion for holding and receiving the substrate 8 on which electronic components are mounted. By driving the substrate positioning unit 1, the substrate 8 held by the lower receiving unit is moved in the X direction and the Y direction to adjust the position of the substrate 8 during screen printing.

  A substrate transport mechanism 5 including a transport conveyor 6 is disposed above the substrate positioning unit 1. As shown in FIG. 2, the transport conveyor 6 is connected to a carry-in conveyor 19A and a carry-out conveyor 19B. The carry conveyor 6 receives the substrate 8 received from the upstream carry-in conveyor 19A to the substrate positioning unit 1 in the X direction (perpendicular to the paper surface). Direction). Then, the printed substrate 8 is transferred from the conveyor 6 to the downstream conveyor 19B.

  Each of the conveyor 6, the carry-in conveyor 19A, and the carry-out conveyor 19B includes a conveyor belt (see FIG. 5) that is stretched in the horizontal direction. By driving a conveyor drive unit (see FIG. 3), The placed substrate 8 is transported. The conveyor 6 includes a pair of clampers 7, which are driven in the horizontal direction by a clamp driving mechanism 17 so as to sandwich and hold the side end portion of the substrate 8 positioned by the substrate positioning unit 1.

  A screen printing unit 10 is disposed above the substrate positioning unit 1. The screen printing unit 10 includes a mask plate 12 and a squeegee head 13 that are spread on a mask holder 11. The squeegee head 13 includes a pair of squeegees 16 that are raised and lowered by a squeegee raising / lowering mechanism 15 provided on the moving plate 14, and can be reciprocated in a horizontal direction (Y direction) by a moving means (not shown). In a state where the substrate 8 is in contact with the lower surface of the mask plate 12, cream solder is supplied onto the mask plate 12, and the squeegee 16 is brought into contact with the surface of the mask plate 12 and is slid on the surface of the substrate 8. The cream solder is printed through the pattern holes 12a.

  A substrate stop mechanism 9 is disposed on the transport conveyor 6, and the substrate stop mechanism 9 stops the substrate 8 transported by the transport conveyor 6 at a predetermined substrate stop position. A substrate detection sensor 18 is disposed at the substrate stop position 9. The substrate detection sensor 18 detects the presence or absence of the substrate 8 at the substrate stop position of the substrate transport mechanism 5 using a retroreflective optical sensor combined with the reflection unit.

  Next, functions of the substrate stopping mechanism 9 and the substrate detection sensor 18 will be described with reference to FIG. As shown in FIG. 3A, the substrate stop mechanism 9 has a structure in which a substrate stopper 20 is provided at a substrate stop position along the transfer conveyor 6 so as to be able to rise and fall around a pin 20a. The raising / lowering operation of the substrate stopper 20 is driven by the raising / lowering mechanism 22, and the raising / lowering mechanism 22 is controlled by the control unit 23.

In the state where the substrate stopper 20 stands upright, the substrate stopper 20 stands upright while crossing the substrate transport level L by the transport conveyor 6 as shown in FIG. Then, the substrate 8 transported on the transport conveyor 6 approaches the stop position, and the front end of the substrate 8 comes into contact with the substrate stopper 20, whereby the movement of the substrate 8 is stopped. Further, in a state where the substrate stopper 20 is laid down, the substrate 8 on the transport conveyor 6 moves in the transport direction without causing interference with the substrate stopper 20.

  A substrate detection sensor 18 is disposed at a position closest to the upstream side of the transport direction of the substrate stopper 20 with the light projecting direction toward the substrate transport level. The substrate detection sensor 18 includes a light projecting unit and a light receiving unit, and is a regressive reflection type optical sensor that detects the presence / absence of a detection target based on the presence / absence of reflected light reflected from a specific reflecting surface. . A reflecting portion 21 provided with a reflecting surface 21a is fixed to the top of the substrate stopper 20, and the light projected from the light projecting portion is reflected by the reflecting surface 21a and received by the light receiving portion. The presence or absence of the substrate 8 to be detected is detected.

  That is, as shown in FIG. 3B, when the substrate 8 is stopped by the substrate stopper 20 at the substrate stop position of the substrate transport mechanism, the light projected from the substrate detection sensor 18 is blocked by the substrate 8 and reflected. The part 21 is not irradiated. Therefore, the substrate detection sensor 18 does not receive the reflected light from the reflecting surface 21a, and “substrate presence” is detected. When the substrate 8 has not yet arrived at the substrate stop position, the light projected from the substrate detection sensor 18 is irradiated to the reflecting portion 21 without being blocked, reflected by the reflecting surface 21a, and then reflected by the substrate detection sensor 18. The reflected light is received. Thereby, “no substrate” is detected.

  A detection signal from the substrate detection sensor 18 is sent to the control unit 23, and the control unit 23 controls the transport driving unit 24 and the raising / lowering mechanism 22 based on the detection signal, whereby a predetermined transport operation is performed. In the substrate detection process by the control unit 23, the control unit 23 receives a detection signal from the substrate detection sensor 18 and outputs a substrate detection result only at a predetermined timing predetermined in the operation sequence. That is, in combination with the raising / lowering operation of the substrate stopper 20, the control unit 23 captures the detection signal of the substrate detection sensor 18 only when the substrate stopper 20 is raised for the purpose of stopping the movement of the substrate 8. Yes.

  Next, a substrate detection method for detecting the presence or absence of the substrate 8 at the substrate stop position of the substrate transport mechanism 5 in this transport operation will be described with reference to FIG. As shown to Fig.4 (a), the board | substrate 8 is mounted on the conveyance belt of the conveyance conveyor 6, and is moving along the movement path | route from the upstream. At this time, the substrate stopper 20 of the substrate stopping mechanism 9 is in a lying state. Then, as shown in FIG. 4B, at a timing when the substrate 8 further moves and comes closer to the substrate stop position, the raising / lowering mechanism 22 is driven to raise the substrate stopper 20, and the substrate transfer mechanism 5 moves the substrate 8. A state in which the movement can be blocked is made (stopper standing step).

  If the board | substrate stopper 20 is stood up, it will be in the state which can receive the detection signal by the board | substrate detection sensor 18 by the control part 23 (detection preparation process). As a result, the substrate detection sensor 18 can detect the presence or absence of the substrate 8 at the substrate stop position. Then, as shown in FIG. 4B, in a state where the substrate 8 has not arrived at the substrate stop position where the substrate stopper 20 is provided, the light irradiated from the light projecting portion of the substrate detection sensor 20 is the end of the substrate stopper 20. The reflected light reflected by the reflecting part 21 provided in the part is received by the light receiving part of the substrate detection sensor 18 to detect “no substrate” (substrate no detection step).

Thereafter, when the substrate 8 moves further downstream, the front end portion 3a of the substrate 8 comes into contact with the substrate stopper 20, as shown in FIG. Thereby, the substrate 8 stops moving. In this state, the projection light from the light projecting portion of the substrate detection sensor 18 is shielded by the substrate 8, and the presence of the substrate 8 at the stop position is detected. That is, when the substrate 8 arrives at the substrate stop position and is prevented from moving by the substrate stopper 20, the light emitted from the light projecting unit of the substrate detection sensor 20 is blocked by the substrate 8 and reflected from the reflecting unit 21. When the light receiving unit of the substrate detection sensor 20 does not receive the light, “substrate presence” is detected (substrate presence detection step).

  Based on this detection signal, a subsequent operation sequence such as a substrate positioning operation proceeds. In this substrate detection, the detection position of the substrate 8 to be detected is always the closest position to the front end portion of the substrate 8, and an irregular portion such as an opening provided in the substrate 8 becomes the detection position. do not do. Therefore, it is possible to prevent erroneous detection due to irradiation of projection light of the substrate detection sensor to the irregular portion having such a shape.

  Thereafter, when the positioning operation for positioning the substrate 8 with respect to the mask plate 12 by the substrate positioning unit 1 is completed, the substrate stopper 20 is laid down as shown in FIG. The detection signal is disabled (detection stop process). Thereby, the erroneous detection by receiving the reflected light from the mask plate 12 located above does not occur.

  Next, as shown in FIG. 4 (e), the Z-axis table 4 is driven to raise the substrate 8, the substrate 8 is brought into contact with the lower surface of the mask plate 12, and then screen printing on the substrate 8 is executed. . After the screen printing is finished and the plate is separated to separate the substrate 8 from the mask plate 12, the substrate 8 is transported to the downstream side, and one cycle of the screen printing operation is completed. When the next substrate is carried in, the steps of stopper erection, detection preparation, substrate non-detection, substrate presence detection, and detection stop are sequentially executed.

  As described above, the substrate detection method shown in the present embodiment has a configuration in which a retroreflective optical sensor is used as the substrate detection sensor 18 and the reflection portion 21 is disposed at the end of the substrate stopper 20. Substrate detection processing is performed while controlling reception / non-reception of the detection signal of the detection sensor 18 in synchronization with the operation of the substrate stopper 20.

  Therefore, even when the color and surface gloss of the detection target part differ depending on the type of the detection target substrate, the detection result by the substrate detection sensor does not depend on the color or surface property of the substrate. Accordingly, it is possible to reliably prevent erroneous substrate detection by the substrate detection sensor at the substrate stop position.

  In the above embodiment, an example in which the present invention is applied to a screen printing apparatus as an electronic component mounting apparatus has been described. However, the present invention is not limited to this, and an electronic component is mounted on a substrate. The present invention can also be applied to a device that transports a substrate by a similar substrate transport mechanism, such as a mounting device.

  The substrate detection method in the electronic component mounting apparatus according to the present invention has an effect that the erroneous detection of the substrate detection sensor at the substrate stop position can be surely prevented, and an electronic component such as an electronic component mounting apparatus or a screen printing apparatus. The mounting apparatus can be used for detecting the presence or absence of a substrate at a substrate stop position of the substrate transport mechanism.

The side view of the screen printing apparatus of one embodiment of this invention The top view of the screen printing apparatus of one embodiment of this invention Structure explanatory drawing of the board | substrate stopper of the screen printing apparatus of one embodiment of this invention Explanatory drawing of the board | substrate detection method in the screen printing method of one embodiment of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate positioning part 5 Substrate transport mechanism 6 Conveyor 8 Substrate 9 Substrate stop mechanism 18 Substrate detection sensor 20 Substrate stopper 21 Reflector 22 Tilting mechanism

Claims (1)

In the electronic component mounting apparatus used in the process of manufacturing the mounting substrate in which the electronic component is mounted on the substrate, the substrate detection method in the electronic component mounting apparatus for detecting the presence or absence of the substrate at the substrate stop position of the substrate transport mechanism, A substrate stopper provided at the substrate stop position so as to be tiltable, a tilting mechanism for driving the tilting operation of the substrate stopper, and a control unit for controlling the tilting mechanism,
Distribution wherein the stopper standing step to prevent ready movement of the base plate in the substrate transfer mechanism for the substrate stopper is erected, with its projecting direction to the substrate conveying level side to the nearest position of the upstream side of the substrate stopper A detection preparation step for receiving a detection signal from a substrate detection sensor using a retroreflective optical sensor provided, and a light emitting unit of the substrate detection sensor in a state where the substrate has not arrived at the substrate stop position. A substrate non-detecting step of detecting “no substrate” by receiving the reflected light reflected by the reflecting portion provided at the end of the substrate stopper by the light receiving unit of the substrate detection sensor; and The light emitted from the light projecting portion of the substrate detection sensor in the state where the substrate stop position is reached and the movement is blocked by the substrate stopper is blocked by the substrate. Includes a substrate chromatic detection step of detecting a "substrate present" by the light receiving unit does not receive Shako, a detection stopping step of the reception disabled state detection signal by said substrate detecting sensor causes the collapsed said substrate stopper,
The control unit receives a detection signal from the substrate detection sensor at a predetermined timing predetermined in an operation sequence, and controls the raising / lowering mechanism based on the detection signal to stop the movement of the substrate. The substrate detection method in the electronic component mounting apparatus, wherein the control unit captures a detection signal of the substrate detection sensor only in a state where the substrate stopper is erected.

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