JP5018766B2 - Mounting method of electronic parts - Google Patents

Description

  The present invention relates to an electronic component mounting method for mounting a plurality of electronic components adjacent to each other on a substrate.

When an electronic component held by a nozzle by suction is mounted on a substrate, a vacuum break is made to smoothly detach the electronic component by blowing inside the nozzle. Blowed air may interfere with electronic components already mounted in the vicinity, so the strength of the blow should be low so that the electronic components are not blown away or the mounting position is not displaced. Is set. However, when the nozzle adsorbs a position shifted from the center of the electronic component, the distance from the electronic component in the shifted direction is shortened, and the blown air may adversely affect the mounting state. Therefore, conventionally, when the nozzle is sucking a position that is largely deviated from the center of the electronic component, it has been proposed to discontinue the mounting of the electronic component and discard the sucked electronic component (Patent Document 1). reference).
JP 2002-151896 A

  However, it is possible to avoid the adverse effects on nearby electronic parts by not blowing, but because the discarded electronic parts are discarded once and new electronic parts are picked up, they are re-mounted, which is a waste of disposal. There is a problem that production costs are reduced as well as cost is increased.

  An object of the present invention is to provide an electronic component mounting method capable of mounting an electronic component without affecting the already mounted electronic component by blowing.

The electronic component mounting method according to claim 1 includes a step of lowering a nozzle adsorbing the electronic component toward the substrate, a step of blowing the inside of the nozzle with a predetermined blow pressure while the nozzle is descending, The step of bringing the electronic component into contact with the substrate when the internal pressure of the nozzle being transferred to the positive pressure side is negative, the step of continuing to blow inside the nozzle while the electronic component is pressed against the substrate for a predetermined time, A first electronic component mounting method including a step of raising the nozzle while continuing, a step of lowering the nozzle adsorbing the electronic component toward the substrate, and the inside of the nozzle during the lowering of the nozzle A step of blowing at a blow pressure lower than the blow pressure, a step of bringing the electronic component into contact with the substrate when the internal pressure of the nozzle being shifted to the positive pressure side by the blow is negative, and the electronic component being longer than the predetermined time Together comprising the steps of continuing the blowing of the interior of the nozzle pressed against between the substrate, the second electronic component mounting method comprising the step of raising the nozzle while continuing blow. The first electronic component mounting method or the second electronic component mounting is performed based on the printed state of the solder that joins another electronic component already mounted adjacent to the planned mounting location of the electronic component to the substrate. Decide which method to use.

  By reducing the blow pressure when the electronic component is mounted on the substrate, the mounting operation can be continued so as not to affect the adjacent electronic component. The time until the internal pressure of the nozzle shifts to the positive pressure side becomes longer as much as the blow pressure decreases, but if the blow pressure is not reduced, the electronic component mounting quality can be increased by pressing the electronic component against the board for a longer time. Can be secured.

  Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a diagram showing the configuration of an electronic component mounting mechanism, FIG. 2 is a timing chart showing the relationship between the movement of a nozzle and the open / closed state of an adsorption valve and a blow valve, and FIG. 3 is a flowchart showing an electronic component mounting operation.

  First, a mechanism related to an electronic component mounting operation will be described with reference to FIG. The mounting head 1 is provided with a plurality of nozzles 2 so as to be movable in the vertical direction, and is movable in the horizontal direction with respect to the substrate 3 fixed in a horizontal position at a predetermined position. Each nozzle 2 is connected to a vacuum pump 5 via an adsorption valve 4, and is connected to an air source 7 via a blow valve 6. In the state where the blow valve 6 is closed and the suction valve 4 is opened, the inside of the nozzle 2 is sucked into a negative pressure, and the electronic component 8 can be sucked and held by the nozzle 2 (the initial position on the left side in the figure). 3 nozzles). On the other hand, when the suction valve 4 is closed and the blow valve 6 is opened, the internal pressure of the nozzle 2 is shifted from the negative pressure to the positive pressure side by the breath air, and the electronic component 8 adsorbed on the nozzle 2 is forcibly removed. Is possible. The nozzle 2 in the mounting position on the right side is in a so-called vacuum break state in which the inside has shifted from a negative pressure to a positive pressure, so that the electronic component 8 can be smoothly detached from the nozzle 2 and transferred to the substrate 3. it can. The blow pressure for blowing the inside of the nozzle 2 can be arbitrarily adjusted by the opening of the valve of the regulator 9. The control unit 10 performs control related to adjustment of the opening degree of the regulator 9, adjustment of opening / closing timings of the intake valve 4 and the blow valve 6, and movement of the nozzle 2.

  Next, the relationship between the movement of the nozzle and the open / close state of the suction valve and the blow valve will be described with reference to the timing chart shown in FIG. The upper graph in the timing chart represents the position of the nozzle. The lower graph represents the open / close state of the intake valve 4 and the blow valve 6. The middle graph shows the change in the internal pressure of the nozzle 2 that occurs as a result of changing the open / close state of the intake valve 4 and the blow valve 6.

In the process of mounting the electronic component 8 on the substrate 3, the nozzle 2 starts moving (lowering) toward the mounting position in order to mount the sucked electronic component 8 on the substrate 3 (time T ₁ ). It continues to move at a constant speed and reaches the mounting position after a predetermined time (time T ₃ ). During the movement of the nozzle 2, the intake valve 4 that has been opened is closed, and the blow valve 6 that has been closed is opened (time T ₂ ). As a result, the internal pressure of the nozzle 2 does not immediately shift from negative pressure to positive pressure, gradually shifts to the positive pressure side while maintaining the negative pressure, and changes to positive pressure after the nozzle 2 reaches the mounting position ( time _T 4). Since the internal pressure of the nozzle 2 is negative when the nozzle 2 reaches the mounting position (time T ₃ ), the electronic component 8 contacts the substrate 3 without dropping from the nozzle 2.

The nozzle 2 stays at the mounting position for a predetermined time in order to press the electronic component 8 against the substrate 3 and then starts moving (raising) toward the initial position (time T ₅ ). After the predetermined time has elapsed, the initial position is reached. Is reached (time T ₇ ). During the movement of the nozzle 2, the blow valve 6 is closed was open until then (time T _6). When the nozzle 2 is detached from the electronic component 8 (time T ₅ ), the blow valve 6 is in an open state, and the electronic component 8 mounted on the substrate 3 is pressed against the substrate 3 by the blow pressure, so that the moving nozzle Cannot be taken home with 2. This blow pressure can be adjusted by adjusting the opening of the regulator 9.

When minute electronic components 8 are densely mounted, the influence of the blow pressure is easily exerted on electronic components already installed in the vicinity, and even if a light electronic component is blown or not blown, it is mounted. Since a problem such as shifting the position may occur, in such a case, the electronic component is mounted in a state where the opening of the regulator 9 is narrowed and the blow pressure is reduced. 2 is a timing chart when the blow pressure is lowered, and when the blow pressure is lowered, the valves 4 and 5 are switched at the same timing (time T ₂ ). also, since the transition to a positive pressure at time T ₄₁ later than time T ₄ shifts to the case of usual blow pressure positive pressure, only mounting position a predetermined time for nozzle 2 presses the electronic component 8 substrate 3 The timing (time T ₅₁ ) at which the movement (rise) starts toward the initial position after staying is also shifted behind the timing (time T ₅ ) in the case of normal blow pressure. The nozzle 2 arrives at the initial position (time T ₇₁ ) after a predetermined time has elapsed after starting to move (rise) toward the initial position (time T ₅₁ ). Blow valve 6 during the time T ₆₁ of the movement of the nozzle 2 is closed.

Thus, when the blow pressure is lowered, the nozzle 2 needs to stay in the mounting position for a longer time, the electronic component 8 needs to be pressed against the substrate 3, and the blow valve 6 needs to be opened for a longer time. There is. For this reason, the timing at which the nozzle 2 that has finished mounting the electronic component 8 returns to the initial position also shifts backward, but by increasing the moving speed of the nozzle 2 as indicated by the alternate long and short dash line, the normal blow pressure is reduced. It is possible to return to the initial position at the same timing (time T ₇ ).

  Next, an electronic component mounting method shown in the flowchart of FIG. 3 will be described. In this mounting method, the blow pressure and the time during which the nozzle stays at the mounting position are changed in consideration of the suction position of the electronic component and the solder state of the electronic component mounted in the vicinity. When the nozzle 2 sucks the electronic component 8 (ST1), the suction position of the electronic component 8 is confirmed (ST2). If the nozzle 2 is sucked at an appropriate position (center of the electronic component 8), the blow pressure and the mounting position The electronic component 8 is mounted on the board 3 without changing the residence time (ST3). The suitability of the suction position of the electronic component 8 is determined by measuring the distance of the center of the electronic component 8 with respect to the center of the nozzle 2, and is determined to be appropriate if this distance is within a predetermined threshold. The closer the nozzle 2 is displaced from the center of the electronic component 8, the more the distance between the nozzle 2 and the neighboring electronic component (the electronic component mounted in the direction in which the nozzle 2 is shifted) when the electronic component 8 is mounted. Since the influence of blow becomes significant, the threshold value is determined based on whether blow may affect the mounting state of nearby electronic components.

If the suction position of the electronic component 8 is not appropriate, it is confirmed whether an electronic component adjacent to the place where the electronic component 8 is to be mounted is mounted (ST4), and if there is no adjacent electronic component, the blow pressure is reduced. Therefore, the electronic component 8 is mounted on the substrate 3 without changing the blow pressure and the residence time at the mounting position (ST3). On the other hand, if there is an adjacent electronic component, the solder state of the adjacent electronic component is confirmed (ST5). Whether the solder state is appropriate or not is determined based on the amount and position of the solder. Since the amount and position information of the solder is acquired as data by the inspection performed when the solder is printed on the substrate 3, the suitability of the solder state is determined by checking this data (ST6). If an appropriate amount of solder is accurately printed at a predetermined position, it is determined that the solder state is appropriate.

  If the solder state is appropriate, the electronic component is not easily affected by the blow, and the electronic component 8 is mounted on the substrate 3 without changing the blow pressure and the residence time at the mounting position (ST3). However, when the solder state is not appropriate, the electronic component is easily affected by blow, and is likely to be blown away or displaced. Therefore, if the solder state is not appropriate, the blow pressure is changed (ST7), and the pressure is lowered to such an extent that the adjacent electronic components are not affected. Along with this, the time during which the nozzle 2 stays at the mounting position is also changed (ST8), and by staying for a longer time, the electronic component 8 is placed on the substrate for a predetermined time after the internal pressure of the nozzle 2 shifts to a positive pressure. 3 can be pressed against.

  In this way, even if blow may affect adjacent electronic components, by adjusting the blow pressure to such an extent that it does not affect the electronic components once adsorbed, The electronic component mounting operation can be continued without redoing.

  The present invention is useful particularly in the field of mounting electronic components in a narrow neighborhood.

Diagram showing the structure of the electronic component mounting mechanism Timing chart showing the relationship between the movement of the nozzle and the open / close state of the suction valve and blow valve Flow chart showing electronic component mounting operation

Explanation of symbols

2 Nozzle 3 Substrate 8 Electronic component

Claims (1)

The step of lowering the nozzle that adsorbs the electronic component toward the substrate, the step of blowing the inside of the nozzle with a predetermined blow pressure while the nozzle is lowered, and the internal pressure of the nozzle that is moving to the positive pressure side by the blow is negative. A step of bringing the electronic component into contact with the substrate at the time of pressure, a step of continuing to blow inside the nozzle while the electronic component is pressed against the substrate for a predetermined time, and a step of raising the nozzle while continuing the blowing. 1 electronic component mounting method;
A step of lowering the nozzle that adsorbs the electronic component toward the substrate, a step of blowing the inside of the nozzle at a blow pressure lower than the predetermined blow pressure while the nozzle is being lowered, and a transition to the positive pressure side by the blow The step of bringing the electronic component into contact with the substrate when the internal pressure of the nozzle is negative, the step of continuing to blow inside the nozzle while pressing the electronic component against the substrate for a time longer than the predetermined time, and continuing the blowing An electronic component mounting method using the second electronic component mounting method including a step of raising the nozzle while
The first electronic component mounting method or the second electronic component mounting method is based on the printed state of the solder that joins another electronic component already mounted adjacent to the mounting position of the electronic component to the substrate. An electronic component mounting method characterized by determining which method to use.

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