JPH0239880B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to an apparatus for constructing an electronic circuit by mounting electronic components, particularly leadless small electronic components (so-called chip components), on a board.

(b) Conventional technology Various methods have been proposed for mounting leadless small electronic components on a board, but one of them is a method in which components are picked up one by one with a mounting head that uses vacuum suction and then bonded. There are some that are pressed onto a board coated with a solder paste or solder paste. This method uses carrier tape, magazine,
The parts are sucked up from a supply means such as a tray or parts feeder, but if the parts arrive at the suction point in an inclined position, or if the parts are lifted up due to machine vibrations at the moment of suction, the mounting head may Instead of the regular side surface (top surface), there were cases where the other side surface, which had a small surface area when comparing the areas, was attracted. If this component is left unattended, it will be attached to the board in the same position and the electronic circuit will not be configured properly. Although such a situation does not occur often, if it does occur, the entire board must be treated as a defective product. In particular, in recent years, many boards are equipped with dozens or more of small leadless electronic components on each board, and it is a huge loss to have such a board defective due to a single mounting error. .

(C) Problems to be Solved by the Invention An object of the present invention is to provide an electronic component mounting device that does not mount electronic components in an abnormal posture.

Furthermore, the present invention allows a cam device with a simple structure to switch whether the vacuum suction type component mounting head releases suction at the mounting station and performs component mounting, or passes through the mounting station as it is without releasing suction. The purpose is to do so.

(d) Means for Solving the Problems In the present invention, components are mounted using vacuum suction type component mounting heads arranged around the periphery of an index table. Similarly, a valve attached to the index table is controlled by a cam device outside the table to switch between adsorption and non-adsorption of the mounting head. A valve is normally maintained in only one of the open and closed states, and the cam device is disposed along the movement locus of the valve actuator to move the actuator in a predetermined section against the tendency of the valve to maintain a particular state. The valve is opened during the component suction period and closed during other periods.
The suction error detection station between the suction station and the mounting station has an optical path that crosses the movement locus of the distal end space of the mounting head, so that the parts picked up by the mounting head are not picked up with their normal sides. An optical discrimination device will be installed to determine whether the object is being attracted to the surface of the object, or whether it is being attracted with other sides. The cam arrangement also includes a movable cam disposed astride the loading station and the subsequent abandonment station.

(E) Effect When a part that is picked up with a side other than the normal side crosses the optical path of the optical discrimination device, the optical discrimination device determines that there is a suction error. If the part is picked up with a normal side, it does not cross the optical path of the optical discrimination device, and the optical discrimination device determines that the absorption is normal. When the mounting head picks up a part with its normal side, the movable cam switches the valve to the non-adsorption side to separate the part at the mounting station, and the mounting head picks up the part with its non-regular side. When the parts are suctioned, the parts are carried away from the mounting station to the abandonment station without releasing the suction.

(f) Example In the figure, 1 is an index table that rotates around a vertical axis. As shown in Figure 2,
The index table 1 consists of an upper table 2 and a lower table 3, both of which are fixed to a vertical index shaft 4. The index shaft 4 is supported in a hanging state by a bearing portion 6 of a support beam 5, and is connected to an index device main body 7 on the beam. The inside of the index shaft 4 is an air intake passage 8 communicating with a vacuum source (not shown). Now, the index table 1 rotates in steps of 45 degrees, and eight stations are arranged around the periphery, and eight arms 9 are made to protrude radially from the lower table 3 accordingly. Among the stations, is an adsorption station, is an adsorption error determination station, is an attachment station, and is an abandonment station.

The arm 9 is supported by a slider 10 mounted perpendicularly to the peripheral surface of the lower table 3, and is movable in the vertical direction. The slider 10 is pulled up by a spring 11 stretched between it and the upper table 2 until it hits a stopper bolt 12 screwed into the upper table 2. The slide 10 has an outwardly projecting roller 13 which is subjected to the pressing action of a tappet 14 at the suction station. Similar tapepets are placed at the mounting station and other necessary stations, both of which are raised and lowered by cam action.

Arm 9 supports a mounting head 15 at its tip.
The mounting head 15 is hollow, has a hose 16 connected to its upper end, and has a suction nozzle 17 protruding from its lower end. The nozzle 17 is adapted to be slidable relative to the mounting head 15 and is normally pushed into the extended position by a spring 18. hose 16
The other end is connected to a valve 19 fixed to the upper table 2. The valve 19 is connected to the intake path 8 through a hose 20, and is used to turn the suction power ON and OFF. The valve 19 is opened and closed by a lever actuator 21 having a roller at its tip. That is, the valve 19 is normally maintained in a closed state, and opens only when the actuator 21 is pushed down. Control of the actuator 21 is performed by displacing the actuator 21 against the tendency of the valve 19 to remain closed using a cam device disposed along its movement locus. The cam device includes a movable cam 23 disposed on the suction station, a movable cam 25 disposed astride the attachment station and the abandonment station, and a fixed cam 2 disposed on the station between them and the suction error determination station.
Consisting of 6. The movable cams 23 and 25 are moved up and down by air cylinders 22 and 24. The fixed cam 26 is fixed to the bearing part 6. The fixed cam 26 also serves as a support member for the air cylinders 22, 24, and the movable cams 23, 25 form a plane substantially continuous with the fixed cam 26 when lowered.
Since each valve 19 is arranged at a delayed position with respect to the mounting head 15 to which it belongs, the movable cams 23, 2
5 is also located at a position offset from the station to which it belongs.

27 is a carrier tape for supplying parts arranged on the suction station. Carrier tape 27
The flat hexahedral parts 28 are dropped one by one into holes punched at regular intervals in a cardboard base, and both sides are sealed with plastic film.
Only the film 29 on the upper surface side is peeled off just before the suction position. On the other hand, an X-Y table 31 on which a board 30 is placed is arranged at the mounting station.
A parts collection box 32 is also arranged at the abandonment station. Reference numeral 33 denotes an optical discrimination device disposed in the suction error discrimination station. This is composed of a photocoupler, and its optical path is connected to the mounting head 15.
(To be more precise, the space at the tip of the nozzle 17, where the attracted part 28 occupies the position) is arranged so as to cross the movement locus of the space at the tip of the nozzle 17. In the embodiment, it is placed at a height such that the light passes directly below the component 28 that has been successfully suctioned.

Next, the effect will be explained. 4 and 5 show the behavior of the mounting head 15 at the suction station, the suction error determination station, the mounting station, and the abandonment station at specific times. 2 corresponds to FIG. 4, and FIG. 3 corresponds to FIG. 5. FIG. 4 shows a state in which each mounting head 15 has just been moved from the previous station. At the suction station, the movable cam 23 is still in the raised state and the mounting head 15 has not started suction. The mounting head 15 located at the station and the suction error determination station has a valve 19 in an open state due to the action of a fixed cam 26, and holds a component 28 by suction. At the suction error determination station, an optical determination device 33 inspects the posture of the component 28. If the part 28 is attracted in a normal position as shown in the figure, that is, with the side surface with the largest area facing upward, the part 28 will not cast a shadow on the optical path of the optical discriminator 33, so it will be determined that there is no problem. . Movable cam 25 at the mounting station and abandonment station
is in a lowered state, and the mounting head 15 is exerting a suction force. Following this state, the operation shown in FIG. 5 occurs. That is, in the suction station, the slider 10 is pushed down by the tappet 14, and the nozzle 17 of the mounting head 15 hits the component 28. After being hit, the movable cam 23 descends and starts attracting the nozzle 17. The slider 10 also descends at the mounting station, and here the picked-up component 28 is pressed against the board 30. Thereafter, the movable cam 25 rises and stops attracting the component 28. When the suction of the component 28 is started or finished, the slider 10 of the suction station and the mounting station rises.
Each loading head 15 begins moving to the next station. In order not to interrupt the suction of the mounting head 15 coming from the suction error detection station,
The movable cam 25 immediately descends and waits after the slider 10 ascends. The other movable cam 23
After the actuator 21 that was being pushed moves below the cam 26, it rises and waits for the next actuator 21.

Next, the operation when the optical discriminator 33 discovers an error in suctioning the component 28 will be explained with reference to FIG. If the component 28 is picked up in an upright position with a side other than the normal side, that is, with a side other than the side with the largest area, the optical path of the optical discrimination device 33 will be blocked, which may result in a suction error. Judgment is made. The mounting head 15 for which this determination has been made will not perform a lowering operation when it next moves to the mounting station. The movable cam 25 also maintains its lowered state until the mounting head 15 moves to the abandonment station, thereby continuing the suction. The mounting head 15 that has moved to the abandonment station is cut off from suction when the subsequent mounting head finishes pressing the component onto the board 30 and the suction is cut off together, and the component 28 is placed in the collection box 32.
drop it on In addition, if even the succeeding mounting head has caused a suction error, the suction of the mounting head 15 will not be cut off while it remains at the abandonment station, but in this case, the suction of the mounting head 15 will not be cut off while it remains at the abandonment station. At this time, when the actuator 21 leaves the movable cam 25, the suction is released and the parts 28 are dropped into the collection box 32.

There are many leadless electronic components with different dimensions and thicknesses, but when mounting components of various thicknesses on the same board,
The support level of the optical discrimination device 33 may be changed depending on the type.

(G) Effects of the Invention According to the present invention, parts picked up in a position other than the normal position are detected by an optical discrimination device and are not mounted, thereby completely eliminating board defects caused by mounting the parts in an incorrect position. can do. In addition, the part posture is monitored by crossing the movement trajectory of the distal end space of the mounting head with the optical path of the optical discriminator, and the part posture is not checked by applying physical force. Even if parts are picked up in a certain position, they will not fall off in an undesirable location and can be reliably discarded at the abandonment station, and no physical force will be applied to the mounting head, so there will be no damage to the mounting head. Nor. Moreover, since switching between adsorption and non-adsorption is performed by displacement of the actuator using a cam of a valve that normally maintains only one of the open and closed states, a fixed cam is required to maintain the switching state for a long period of time. It is sufficient and the configuration is simple. Different valve operations are required at the attachment station and abandonment station depending on whether the part is to be attached or not, but the valve operations at both stations are performed by one valve operation that spans both stations. The configuration is simplified in this aspect as well, since this is covered by a movable cam.

[Brief explanation of drawings]

The figures show an embodiment of the apparatus of the present invention, in which FIG. 1 is a top view of an index table, and FIGS. 2 and 3 are partial vertical sectional views showing different operating states of the suction station. Figures 4 to 6 are operation explanatory diagrams, Figures 4 and 5 show the operations at each station at the same time in parallel, and Figure 6 shows the operation in the case of a suction error. This shows the operations at the station step by step. DESCRIPTION OF SYMBOLS 1... Index table, 15... Mounting head, 28... Parts, 30... Board,... Adsorption station,... Mounting station,...
Adsorption error determination station, ... abandonment station, 19 ... valve, 21 ... actuator, 23, 25 ... movable cam, 26 ... fixed cam, 33 ... optical discrimination device.

Claims (1)

[Scope of Claims] 1. An index table that arranges a plurality of vacuum suction type component mounting heads around its periphery and sequentially stops these mounting heads at a plurality of work stations; a valve that is provided on the index table for each mounting head and normally maintains only one of the open and closed states, and a valve that is arranged outside the index table along the movement locus of the actuator of the valve; a cam device that displaces the actuator in a predetermined section against the valve's tendency to maintain a particular state, and keeps the valve in an open state during a component suction period and in a closed state during other periods; A suction error detection station is placed between the suction station that suctions the component and the mounting station that mounts the component onto the board. an optical discrimination device that determines whether the component is being picked up with a normal side or with a different side; It is placed astride the station, and when the mounting head picks up the part with its normal side, it switches the valve to the non-sucking side and separates the part at the mounting station, and the mounting head picks up the part with its normal side. An electronic component mounting device characterized by comprising a movable cam that transports a component away from a mounting station to a discarding station without releasing the attraction when the component is attracted with a side other than that of the mounting station.