JP2008078295A - Electronic component mounting device and nozzle inspecting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic component mounting device capable of detecting corner undercut in a nozzle absorbing surface, and to provide a nozzle inspecting method. <P>SOLUTION: Sensor light L is irradiated between a pair of transmission sensors in a direction which makes an inclination angle with respect to vertical and horizontal directions of the absorbing surface 4a in a nozzle 4 to be inspected. A detection light receiving amount detected by a light receiving amount detecting part is compared with a normal light receiving amount set preciously in an abnormality detecting part. When a difference between the normal light receiving amount and the detection light receiving amount exceeds a normal light receiving amount permission value, it is determined that the inspected nozzle 4 is an abnormal nozzle where the corner undercut 4b occurs in the absorbing part 4a. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electronic component mounting apparatus for transferring an electronic component sucked by a nozzle onto a substrate, and a nozzle inspection method.

In the field of electronic component mounting, an electronic component mounting apparatus provided with a nozzle that picks up an electronic component and transfers it to a substrate is widely used. The lower end portion of the nozzle is a suction surface that comes into contact with the upper surface of the electronic component, and the electronic component is sucked to the lower end portion of the nozzle by maintaining the suction surface at a negative pressure. Since the nozzle repeatedly performs the suction operation for sucking the electronic components and the mounting operation for pressing the sucked electronic components against the board, the nozzle suction surface has oil applied to the solder and air applied to the board side. Dirt such as adhesion of foreign matter such as mist or deformation such as corner dropping (missing at the peripheral portion of the suction surface) due to external force such as a pressing load during mounting may occur. If the nozzles thus contaminated are continuously used, the electronic components cannot be sucked in a normal posture, and the mounting accuracy is adversely affected. In addition, the suction force is reduced due to air leakage generated from a gap formed between the upper surface of the electronic component and the suction surface of the nozzle. Electronic components may fall from the nozzle. In order to solve such a problem, a method has been proposed in which normal or abnormal inspection of the nozzle is performed by grasping the state of the suction surface from the luminance distribution of the suction surface of the nozzle (see Patent Document 1).
JP 2002-190697 A

  However, when a foreign material of a material different from the material of the nozzle itself, for example, a low-reflective substance such as solder cream, is attached to the suction surface, a change in luminance is likely to appear clearly, and the state of the suction surface is easily detected. However, deformation of the suction surface due to corner drop occurs in the outer peripheral part where the luminance change is large, and the corner drop part and other normal parts are made of the same material. It was difficult to grasp.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an abnormal electronic component mounting apparatus and a nozzle inspection method that can accurately detect a corner drop of a suction surface of a nozzle.

  The invention according to claim 1 is an electronic component mounting apparatus for transferring an electronic component adsorbed on a suction surface of a nozzle whose axial center is directed in a vertical direction onto a substrate, wherein one of the opposing components is disposed above the other. A pair of transmission sensors; a rotating means for rotating the nozzle around its axis; a relative position changing means for changing a relative vertical position and a horizontal position of the nozzle and the pair of transmission sensors; A received light amount detecting means for detecting a received light amount of sensor light projected and received between the pair of transmission sensors when the relative horizontal positional relationship with the pair of transmission sensors is changed, and the nozzle on the suction surface A normal received light amount storage unit that stores the received light amount detected by the received light amount detection unit as a normal received light amount when there is no change in shape, and the detected light amount detection unit detects the inspection target nozzle. Nozzle state determination means for determining whether the inspection target nozzle is normal or abnormal by comparing the amount of light received and received and the amount of normal light received, and the relative position changing means has the suction surface in the vertical direction and the horizontal direction. At a position between the pair of transmission sensors, the nozzle and the pair of transmission sensors are relatively positioned in a direction that forms an inclination angle in the horizontal direction and the irradiation direction of sensor light projected and received between the pair of transmission sensors. Change the horizontal position.

  According to a second aspect of the present invention, in the first aspect of the invention, an inclination angle with respect to a horizontal plane of a sensor light irradiated and received between the pair of transmission sensors with respect to a horizontal plane is 45 degrees, and the pair of transmission sensors The inclination angle in the horizontal plane between the irradiation direction of the sensor light projected and received between and the direction in which the relative horizontal positional relationship between the nozzle and the pair of transmission sensors is changed is 45 degrees.

  A third aspect of the present invention is the nozzle inspection method for the electronic component mounting apparatus according to the first or second aspect, wherein the suction surface is located between the pair of transmission sensors in the vertical direction and the horizontal direction. And changing the relative horizontal positional relationship between the inspection target nozzle and the pair of transmission sensors in a direction that forms an inclination angle in the horizontal plane with the irradiation direction of the sensor light projected and received between the pair of transmission sensors. A first position detecting step for detecting a received light amount of sensor light projected and received between the pair of transmission sensors when a horizontal position change process and a relative horizontal positional relationship between the inspection target nozzle and the pair of transmission sensors are changed. Received light amount detection step, a first determination step for determining normality or abnormality of the inspection target nozzle based on the received light amount detected in the first received light amount detection step, and Light is projected and received between the pair of transmission sensors at a position where the suction surface is between the pair of transmission sensors in the vertical direction and the horizontal direction. A second horizontal position that changes a relative horizontal positional relationship between the inspection target nozzle and the pair of transmission sensors rotated by 180 degrees around the axis in a direction that forms an inclination angle in a horizontal plane with an irradiation direction of the sensor light. A sensor that transmits and receives light between the pair of transmission sensors when the relative horizontal positional relationship between the position change step and the inspection target nozzle rotated 180 degrees around the axis and the pair of transmission sensors is changed. Based on the second received light amount detection step for detecting the received light amount and the received light amount detected in the second received light amount detection step, whether the inspection target nozzle is normal or abnormal is determined. Comprising a second determination step.

  According to the present invention, it is possible to determine whether a nozzle to be inspected is normal or abnormal based on the amount of received light that varies depending on whether or not the suction surface of the nozzle is dropped.

  Embodiments of the present invention will be described with reference to the drawings. 1 is a plan view of an electronic component mounting apparatus according to an embodiment of the present invention, FIG. 2 is a side view of the electronic component mounting apparatus according to the embodiment of the present invention, and FIG. 3 is an electronic component mounting apparatus according to the embodiment of the present invention. FIG. 4 is an explanatory diagram showing the positional relationship between the suction surface of the nozzle and the pair of transmission sensors, and FIG. 5 is an explanatory diagram showing the relationship between the deformation of the nozzle and the transmission of sensor light. FIG. 6 is an explanatory diagram showing the relationship between the nozzles and the sensor light irradiation direction, and FIG. 7 is a flowchart showing a nozzle inspection method in the electronic component mounting apparatus according to the embodiment of the present invention.

  1 and 2, an electronic component mounting apparatus includes a transport rail 2 that transports a substrate 1 on which electronic components are to be mounted to a predetermined position, and a plurality of parts feeders 3 that each store a plurality of electronic components so as to be supplied. And a head 5 for attracting electronic components supplied from the parts feeder 3 by a plurality of nozzles 4 and transferring them onto the substrate 1, and a horizontal moving means for horizontally moving the head 5 above the parts feeder 3 and the substrate 1. An XY orthogonal robot 6, a component camera 7, which is a component imaging unit that images the electronic component sucked by the nozzle 4 from below, and a substrate imaging unit that is integrally provided in the head 5 and images the substrate 1 from above. A substrate camera 8 and a sensor 9 for inspecting the state of the suction portion provided at the tip of the nozzle 4 are provided.

In FIG. 3, the head drive unit 10 includes an X-axis motor 11 and a Y-axis motor 12 that are drive units of the XY orthogonal robot 6, a Z-axis motor 13 that moves each nozzle 4 in the vertical direction (Z direction), A θ-axis motor 14 which is a rotating means for rotating the nozzle 4 around the axis (θ direction) is a constituent element. The head drive unit 10 receives the control command from the control unit 15 and controls the operation of each component, and can arbitrarily adjust the position of each nozzle 4 in the XYZ direction and the rotation angle in the θ direction.

  In FIG. 4, a sensor 9 is a pair of transmission sensors each composed of a light projecting unit and a light receiving unit that face each other. 4 (a) and 4 (b), the pair of transmission sensors 9a and 9b has a difference in position in the Z direction, respectively, and the irradiation direction of the sensor light L projected and received between the pair of transmission sensors 9a and 9b. One transmission sensor 9a is arranged above the other transmission sensor 9b so that the inclination angle α with respect to the XY horizontal plane is 45 degrees. Accordingly, in FIG. 4C, the pair of transmission sensors 9a and 9b are arranged with different positions in the XY directions, and sensor light is transmitted and received between the pair of transmission sensors 9a and 9b. The inclination angles β and γ with respect to the X direction and the Y direction of the irradiation direction of L are 45 degrees. By the operation control of the head driving unit 10 (see FIG. 3), the position where the suction surface 4a provided at the lower end of the nozzle 4 is between the pair of transmission sensors 9a and 9b in the X direction, the Y direction, and the Z direction, that is, the nozzle Of the sensor light L projected and received between the pair of transmission sensors 9a and 9b by moving the nozzle 4 to be inspected to the inspection position and moving it in the X direction (see arrow A) as the inspection direction. The relative horizontal positional relationship between the nozzle 4 and the pair of transmission sensors 9a and 9b is changed in a direction that makes an inclination angle β in the direction and the XY horizontal plane. With the change in the horizontal positional relationship, the sensor light L and the nozzle 4 Intersection changes.

  In FIG. 5A, the sensor light L that is shielded when the nozzle 4 to be inspected is a normal nozzle that is not chipped or deformed in the suction portion 4a is dropped on the suction surface 4a in FIG. 5B. When the part 4b is an abnormal nozzle, it does not pass through the corner drop part 4b and is not shielded. As described above, since the corner drop portion 4b exists, the sensor light L that should not be transmitted through a normal nozzle is transmitted. Therefore, the total amount of received light depends on whether the inspection target is a normal nozzle or an abnormal nozzle. There will be a difference.

  In FIG. 3, the received light amount detection unit 16 transmits and receives sensor light L between the pair of transmission sensors 9 a and 9 b when the relative horizontal positional relationship between the nozzle 4 and the pair of transmission sensors 9 a and 9 b changes. Functions as a received light amount detecting means for detecting the received light amount (detected received light amount 16a). The nozzle state determination unit 17 functions as a nozzle state determination unit that determines whether the inspection target nozzle is normal or abnormal by comparing the detected light reception amount 16a and the normal light reception amount 17a with respect to the inspection target nozzle. The normal received light amount 17a is a received light amount detected by the received light amount detection unit 16 when the nozzle 4 is a normal nozzle having no shape change on the suction surface 4a, and a nozzle state that functions as a normal received light amount storage unit. Pre-stored in the determination unit 17. The nozzle state determination unit 17 further has a normal light reception amount allowable value 17b set in advance. When the difference between the normal light reception amount 17a and the detected light reception amount 16a exceeds the normal light reception amount allowable value 17b, the detection target nozzle is determined. It is determined that the nozzle is an abnormal nozzle in which a deformation such as a corner drop has occurred on the suction surface 4a. The notification unit 18 notifies the operator when the nozzle state determination unit 17 determines that the detection target nozzle is an abnormal nozzle.

  In FIG. 6A, when the rotation angle around the axis of the nozzle 4 is 0 degree, the sensor light L irradiated to the suction surface 4a in a direction that forms an inclination angle in the vertical direction and the horizontal direction, Since only the one side surface 4c, 4d is irradiated and the other side surface 4e, 4f is not irradiated, it is impossible to detect the presence of the corner drop portion 4b facing the other side surface 4e. In this case, when the nozzle 4 is rotated 180 degrees around the axis in FIG. 6B, the sensor light L irradiates the other side surfaces 4e and 4f. Can be detected. As described above, the nozzle 4 to be inspected is inspected twice with the rotation angle around the axis being 0 degrees and 180 degrees, so that all the side surfaces 4c, 4d, 4e, and 4f of the nozzle 4 are formed. It is possible to detect the presence or absence of a facing corner drop portion based on the difference in the amount of received light.

It should be noted that the inclination angles α, β, γ (see FIG. 4) can be set to angles other than 45 degrees. When the suction surface 4a is rectangular like the nozzle 4 in the present embodiment, the corner drop part 4
When irradiation is performed at an angle close to a right angle with respect to the side surface 4e facing b, it is possible to effectively detect the presence of the corner drop portion 4b, but since irradiation is performed at an angle close to parallel to the side surface 4f, It becomes difficult to detect the presence of a corner drop portion facing the side surface 4f. In this case, by rotating the nozzle 4 by 90 degrees, it is possible to effectively detect the corner drop portions facing all the side surfaces 4c, 4d, 4e, and 4f. There is a problem of becoming longer. Therefore, the side surfaces 4c and 4d are irradiated at 45 degrees, and the side surfaces 4e and 4f rotated by 180 degrees are also irradiated at 45 degrees, thereby achieving a balance between the detection accuracy of the corner drop portion and the shortening of the inspection time. ing.

  Further, the X-axis motor 11, the Y-axis motor 12, and the Z-axis motor 13 constituting the head drive unit 10 are configured such that the nozzle 4 and the pair of transmission sensors 9a and 9b are moved by the movement of the nozzle 4 in the vertical and horizontal directions. The relative vertical position and the horizontal position of the pair of transmission sensors 9a and 9b can be freely moved in the vertical direction and the horizontal direction so that the relative positions of the two can be adjusted. It may be changed.

  Next, a nozzle inspection method in the electronic component mounting apparatus will be described with reference to the flowchart of FIG. In the electronic component mounting apparatus, the mounting operation for transferring the electronic component sucked on the suction surface of the nozzle to the substrate is repeatedly performed (ST1). When the preset nozzle inspection time is reached (ST2), the mounting operation is temporarily interrupted. (ST3) The inspection target nozzle is moved to the inspection position (ST4). The inspection target nozzle is moved in the inspection direction at a rotation angle of 0 degrees, and the relative horizontal positional relationship between the inspection target nozzle and the pair of transmission sensors is changed (ST5... First horizontal position changing step). At this time, the received light amount of the sensor light projected and received between the pair of transmission sensors is detected (ST6... First received light amount detection step), and whether the inspection target nozzle is normal or abnormal is determined based on the received light amount. (ST7... First determination step). If it is determined that the detection target nozzle is an abnormal nozzle, an abnormality warning is notified to the operator (ST8). On the other hand, if it is reversed that it is a normal nozzle, the nozzle to be inspected is rotated 180 degrees around its axis (ST9). The inspection target nozzle is moved in the inspection direction at a rotation angle of 180 degrees, and the relative horizontal positional relationship between the inspection target nozzle and the pair of transmission sensors is changed (ST10... Second horizontal position changing step). In the second horizontal position changing step, the nozzle to be inspected in the first horizontal position changing step may be moved in the direction opposite to the inspection direction. When the relative horizontal positional relationship between the inspection target nozzle and the pair of transmission sensors is changed, the amount of sensor light received and received between the pair of transmission sensors is detected (ST11... Second light reception amount) Detection step), normality or abnormality of the inspection target nozzle is determined based on the amount of received light (ST12... Second determination step). If it is determined that the detection target nozzle is an abnormal nozzle, an abnormality warning is notified to the operator (ST13). On the other hand, if it is determined that the nozzle is a normal nozzle, it can be used continuously and the mounting operation is resumed (ST14).

  According to the present invention, it is possible to determine whether a nozzle to be inspected is normal or abnormal based on the amount of received light that varies depending on whether or not the suction surface of the nozzle is dropped. Thus, it is useful in the field of electronic component mounting to be transferred to a substrate.

The top view of the electronic component mounting apparatus of embodiment of this invention The side view of the electronic component mounting apparatus of embodiment of this invention 1 is a partial configuration diagram of a control system of an electronic component mounting apparatus according to an embodiment of the present invention. Explanatory drawing showing the positional relationship between the suction surface of the nozzle and a pair of transmission sensors Explanatory drawing showing the relationship between nozzle deformation and sensor light transmission Explanatory drawing showing the relationship between the nozzle and the irradiation direction of the sensor light The flowchart which shows the inspection method of the nozzle in the electronic component mounting apparatus of embodiment of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Board | substrate 4 Nozzle 4a Suction surface 9, 9a, 9b Transmission sensor 10 Head drive part L Sensor light 16 Light reception amount detection part 17 Nozzle state determination part

Claims (3)

An electronic component mounting apparatus for transferring an electronic component adsorbed on a suction surface of a nozzle whose axis is directed vertically to a substrate,
Changing a relative vertical position and a horizontal position of the pair of transmission sensors in which one facing each other is disposed above the other, rotating means for rotating the nozzle around its axis, and the pair of transmission sensors Receiving light amount detection for detecting the amount of received sensor light between the pair of transmission sensors when the relative horizontal positional relationship between the relative position changing means and the nozzle and the pair of transmission sensors changes. A normal received light amount storage means for storing the received light amount detected by the received light amount detection means as a normal received light amount when the nozzle is normal with no change in shape on the suction surface; A nozzle state determination unit that determines whether the inspection target nozzle is normal or abnormal by comparing the detected light reception amount detected by the amount detection unit and the normal light reception amount,
The relative position changing means has an inclination angle in a horizontal plane and an irradiation direction of sensor light projected and received between the pair of transmission sensors at a position where the suction surface is between the pair of transmission sensors in the vertical direction and the horizontal direction. An electronic component mounting apparatus that changes a relative horizontal positional relationship between the nozzle and the pair of transmission sensors in a direction of forming a line.   The inclination angle of the irradiation direction of the sensor light projected and received between the pair of transmission sensors with respect to the horizontal plane is 45 degrees, the irradiation direction of the sensor light projected and received between the pair of transmission sensors, the nozzle, and the pair of The electronic component mounting apparatus according to claim 1, wherein an inclination angle in a horizontal plane with respect to a direction of changing a relative horizontal positional relationship with the transmission sensor is 45 degrees. A method for inspecting a nozzle in an electronic component mounting apparatus according to claim 1 or 2,
A nozzle to be inspected at a position where the suction surface is between the pair of transmission sensors in the vertical direction and the horizontal direction in a direction that forms an inclination angle with the irradiation direction of the sensor light projected and received between the pair of transmission sensors and the horizontal plane. A first horizontal position changing step for changing a relative horizontal positional relationship between the pair of transmission sensors and the pair of transmission sensors, and a change in the relative horizontal positional relationship between the inspection target nozzle and the pair of transmission sensors. A first received light amount detecting step for detecting a received light amount of the sensor light projected and received between the pair of transmission sensors, and the normality of the inspection target nozzle based on the received light amount detected in the first received light amount detecting step Alternatively, a first determination step for determining abnormality, a step of rotating the nozzle to be inspected by 180 degrees around its axis, a nozzle rotation step, and the suction in the vertical and horizontal directions. The surface rotated between the pair of transmission sensors by 180 degrees around the axis in a direction forming an inclination angle in the horizontal direction and the irradiation direction of sensor light projected and received between the pair of transmission sensors. A second horizontal position changing step of changing a relative horizontal positional relationship between the inspection target nozzle and the pair of transmission sensors; the inspection target nozzle rotated by 180 degrees around the axis; and the pair of transmission sensors Detected in the second received light amount detection step and the second received light amount detection step for detecting the received light amount of the sensor light projected and received between the pair of transmission sensors when the relative horizontal positional relationship of A second determination step of determining normality or abnormality of the inspection target nozzle based on the received light amount;
Nozzle inspection method including

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