JPH0328560Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to a device for mounting electronic components onto a board, and is used in an electronic circuit board assembly process.

(b) Prior Art In recent years, leadless electronic components are often used as components of electronic circuits. Leadless electronic components are attached to a substrate using a sticky substance such as an adhesive or a solder paste, and then mechanically and electrically bonded firmly through a solder dip or solder reflow process. Vacuum chucks are commonly used to attach leadless electronic components to substrates. The suction nozzle of the vacuum chuck is configured to press the leadless electronic component against the board with just the right amount of pressing force using spring pressure. An example of such a configuration is disclosed in Japanese Unexamined Patent Publication No. 1983-
It can be found in Publication No. 184294. The design of the conventional electronic component mounting device described in this publication is aimed at equalizing the force that presses on the component, but it is also designed to ensure reliable attachment without damaging the component. Setting the spring force was not easy.

(c) Problems that the invention aims to solve This invention uses a vacuum chuck to press electronic components onto a board, and when the electronic parts are brought into contact with the board, the pressure is applied softly, and when the pressing is about to be completed, the pressure is applied with sufficient force. The aim is to provide a device that can be added.

(d) Means for solving the problems In the present invention, the vacuum chuck is constructed as follows. In other words, it has a two-stage structure consisting of a main body and a suction nozzle that is movable relative to the main body. energized in the direction of protruding from the part. There is a limit to the relative movement range of the suction nozzle, and the nozzle moves to that limit during the process of pressing the component, and thereafter the biasing force of the first spring is directly applied to the nozzle.

(E) Effect According to the above configuration, when the pressing starts, the electronic component comes into soft contact with the board due to the buffering action of the second spring, which has a weak force, and then the relative movement of the suction nozzle with respect to the main body stops, and the first It is strongly pressed against the board by the force of the spring. This effectively absorbs the impact at the start of contact to prevent damage to the parts, and ultimately eliminates the buffering effect of the second spring, allowing the parts to be firmly attached.

(F) Embodiment In the figure, 1 is a rotary index table, and 2 is a shelf placed on the top of the rotary index table 1. A rotary index table 1 is provided with vacuum chucks 3 at appropriate intervals. The vacuum chuck 3 attracts a leadless electronic component 4 at a certain work station and presses it against a printed wiring board 6 on an XY table 5 at the illustrated station. An adhesive 7 is applied to predetermined locations on the substrate 6. The vacuum chuck 3 has a suction nozzle 9 held at the lower end of a rod-shaped main body 8 so as to be relatively movable a certain distance in the axial direction, and is slidable vertically on the guide sleeve 10 of the rotary index table 1. Supported. At the upper end of the vacuum chuck 3 there is a detent member 1.
Fix 1. The anti-rotation member 11 holds the ball 12 erected on the rotary index table 1 between a pair of rollers 13 as shown in FIG. 5, and prevents the vacuum chuck 3 from rotating around its axis while moving up and down with the vacuum chuck 3. . The vacuum chuck 3 is urged upward by a compression coil spring 15 until the flange 14 of the main body 8 comes into contact with the guide sleeve 10, and is pushed down at a desired station by a pusher 16 supported by the shelf board 2. The pusher 16 is connected to the bell crank 17 on the shelf board 2 by a link rod 18.
It is connected with. At the other end of the bell crank 17,
A cam follower roller 21 is provided that faces a face cam 20 attached to the camshaft 19. The bell crank 17 is biased clockwise in the figure by a tension coil spring 22, which is a first spring, and as the face cam 20 moves, it pushes the pusher 16 and pushes down the vacuum chuck 3. The contraction force of the tension coil spring 22 is sufficient to push down the vacuum chuck 3 against the compression coil spring 15. The suction nozzle 9 is also biased in the direction of protruding from the vacuum chuck main body 8 by a compression coil spring 23, which is a second spring. However, the force applied by the spring 23 is slightly weaker than that applied by the spring 22.

The vacuum chuck 3 has an air valve 2 attached to the suction turret 24 in the center of the rotary index table 1.
5. The air valve 25 is of a type that closes when the actuator 26 is not pressed and opens when the actuator 26 is pressed.
A cam plate 27 is suspended below. The actuator 26 moves from the suction station to the cam plate 27.
, and continues to be pushed to the mounting station (the station shown in Figures 1 to 3). The air valve 25 corresponding to the vacuum chuck 3 that has arrived at the mounting station is attached to the cam plate 27 as shown in FIG.
The actuator 26 is positioned under the tappets 28 lined up and stopped. When the vacuum chuck 3 is lowered by the pusher 16 and the electronic component 4 is pressed against a predetermined location, the tappet 28 is raised to end the suction.

The mounting operation of the electronic component 4 by the above device is as follows. Vacuum chuck 3 holding electronic components 4
When the camshaft 19 reaches the mounting station as shown in Figure 1, the camshaft 19 starts rotating, and the face cam 2
The cam follower roller 21, which had been pushed away by 0, begins to move to the right in the figure. This movement is bellcrank 1
7, the pusher 16 descends and pushes down the vacuum chuck 3. Then, as shown in FIG. 2, the suction nozzle 9 abuts the electronic component 4 against the board 6. At this time, the strong downward force of the spring 22 is buffered by the weak spring 23, and the electronic component 4 is not damaged even though it collides with the board 6 at a considerable speed. After this, the suction nozzle 9 reaches the limit of relative movement with respect to the vacuum chuck main body 8, as shown in FIG. 3, and the component pressing force by the spring 22 is directly applied to the suction nozzle 9. Therefore, the electronic component 4 is forcefully pressed against the substrate 6 and is sufficiently adhered to the adhesive 7.

(g) Effects of the invention According to the invention, since the spring pressure applied to the electronic component is small at the point when it starts to be pressed against the board, the shock does not become excessive even if the vacuum chuck is moved at high speed. Therefore, high-speed operation can be performed without damaging electronic components. In addition, after the electronic components have settled on the board, a stronger pressure is applied, which is different from the conventional method, so that the electronic components can be sufficiently attached to the board.

[Brief explanation of the drawing]

The figures show one embodiment of the present invention, and Figs.
The figures are partially sectional front views of essential parts showing different operating states, FIG. 4 is an explanatory diagram of the operation of the air valve, and FIG. 5 is a top view of the vacuum chuck. 3... Vacuum chuck, 4... Electronic parts, 6...
Substrate, 8... Main body, 9... Adsorption nozzle, 22...
...first spring, 23...second spring.

Claims (1)

[Scope of Claim for Utility Model Registration] In a device that presses an electronic component attracted by a vacuum chuck onto a board in order to bond the electronic component to the board through an adhesive substance such as an adhesive or solder paste, the vacuum chuck is a main body to which a component pressing force is applied by a spring; a suction nozzle attached to the main body so as to be able to move within a certain range; a suction nozzle that is energized in a direction protruding from the main body, During pressing, the suction nozzle is weaker than the first spring, which buffers the suction nozzle until the relative movement of the suction nozzle with respect to the main body stops and the pressing force by the first spring starts to be applied directly to the suction nozzle. An electronic component mounting device comprising: a second spring;