JPH0746760B2 - Electronic component mounting method - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component mounting method and device for mounting a chip-shaped electronic component (hereinafter referred to as a chip component) or the like on a circuit board such as a printed circuit board. is there.

2. Description of the Related Art In the conventional electronic component mounting, as shown in FIG. 6, a chip component 1 is vacuum-sucked by a nozzle 2 and the nozzle 2 is lowered toward a substrate to mount the chip component 2 on the substrate. However, as the suction state of the chip component 2, the cases of (a), (b), (c), and (d) of FIG. 6 can be considered.
6A is a diagram when the chip component is normally sucked, FIG. 6B is a case where the chip component is vertically attracted, FIG. 6C is a case where the chip component is diagonally sucked, and FIG. It is a figure when a chip component is not adsorbed. (B), (c),
(D) is a chip component absorption error, and if it is mounted on the substrate as it is, a mounting error will occur, so this state must be detected.

In such a case, it is generally conceivable to detect the position when the nozzle 2 descends to the substrate and determine whether the mounting is correct or not.

The problem to be solved by the invention is that the components have variations in dimensions caused in the manufacturing process, and it is not possible to accurately determine the mounting error by simply determining the position of the nozzle.

Therefore, in order to solve this problem, the inventors of the present invention, according to JP-A-59-186770, use the upper and lower limits of the dimensional variation of the parts as criteria for judgment, and measure the thickness of the parts on which these are mounted. We proposed a more accurate method to judge the correctness of component mounting by comparing with the value.

The present invention makes it possible to cope with the case where various kinds of parts having different sizes are mounted in the case of utilizing the above invention.

The method of the present invention therefore identifies the type of component to be mounted,
A step of mounting the electronic component on the circuit board; a step of measuring the distance between the circuit board and the lower surface of the component holding portion that holds the electronic component when the electronic component is mounted; By comparing the measured data with the step of selecting and reading out the data of the thickness of the mounted electronic component from the data of the thickness of the plurality of electronic components placed, the electronic component is It is provided with a step of determining whether or not the device is properly mounted.

Operation With the above configuration, it is possible to determine the correctness of each mounting by comparing the thickness data of each of a plurality of components having different sizes with the measured thickness data.

EXAMPLES Examples of the present invention will be described below with reference to the drawings.

An embodiment of the present invention will be described with reference to FIGS. In FIG. 2 and FIG. 3, 11 is a chip component, 12 is a nozzle that adsorbs the chip component 11, 13 is a hollow slide shaft, and the nozzle 12 is fixed to the tip, and slides vertically with a slide bearing 14. Guided as possible. A tube 15 connects the slide shaft 13 and the vacuum source. A differential transformer 17 is fixed to the slide shaft 13 by a bracket 16. A mover 18 of the differential transformer 17 is fixed to a solenoid 20 via a compression spring 19, and the solenoid 20 is fixed to a slide shaft 13 by a bracket 21. In addition, the above-mentioned adsorption part is a compression spring.
With 22 it is possible to escape to a few mm above.

A linear motor 23 is composed of a main body 2A and a bobbin 23B, and a bobbin 23B is formed by applying a command current to the wound bobbin 23B.
Slide shaft fixed to the plate 24 that is integrated with the
13 moves up and down. Reference numeral 25 is a detector that detects the upper and lower positions of the bobbin 23B. The linear motor main body 23A is fixed to the tip of the XY drive device 26 and is positioned at an arbitrary XY position. 27 is a component supply unit that supplies chip components,
28 is a circuit board on which chip components are mounted. Reference numeral 29 denotes a control unit having a built-in microprocessor and storage device, which is configured to perform positioning of the linear motor main body 23A on the XY axes, control of vertical movement of the slide shaft 13, and ON / OFF of component suction. ing.

The operation of the mounting device configured as described above will be described below. First, the XY drive device 26 is moved so that the nozzle 12 is positioned on the component supply unit 27. The nozzle 12 is lowered by the driving of the linear motor 23, and is sucked up after adsorbing the chip component 11. Next, the chip component 11 is moved by the XY driving device 26.
Is transferred to the mounting position on the circuit board 28 with the nozzle 12 adsorbed to the nozzle 12, and the nozzle 12 descends to attach the chip component 11 to the circuit board 28.
Put on. At the same time when the chip component 11 is mounted, the current of the solenoid 20 is cut off, and the compression spring 19 causes the mover 18 to descend. The differential transformer 17 is a well-known displacement sensor, and since the output voltage changes due to the displacement of the mover 18, the nozzle 12 is determined from the change amount of the voltage before and after the mover 18 descends.
Distance from the bottom surface of the circuit board 28, that is, the chip component 11
It is possible to measure the height h when the is attached. When the measurement is completed, a current again flows through the solenoid 20, the mover 18 moves up, and then the nozzle 12 moves up. To do. By repeating the above cycle, the mounting height h is measured while mounting the chip components one after another.

FIG. 4 is a diagram when the nozzle 12 mounts the chip component 11 on the circuit board 28. When (a) is normal, (b) the chip component 11 is mounted vertically, and (c) is the chip. It is a figure at the time of not adhering because of a component suction mistake. When the chip component is properly mounted, the distance between the lower surface of the nozzle 12 and the circuit board 23 is h1, the upper limit value considering the thickness of the chip component and its variation is h3, and the lower limit value is h2, h3 ≧ h1 ≧ It must be h2, and in other cases, it is determined that the chip component is not properly mounted as shown in (b) and (c).

FIG. 5 is a block diagram of the control unit 29, which includes a head 40 and a sensor.
The sequence controller unit 42 and the CPU unit 43 control 41. The data such as the thickness of the chip component is stored in the storage unit 44 which is a part of the CPU unit 43, and the data of the thickness of the plurality of chip components is the upper limit value h3 and the lower limit value h2 for each type.
Is stored, and the thickness data for all types of chip components are stored in this portion.

FIG. 1 is a flowchart of a chip component mounting operation.
The operation will be described below with reference to FIG. First, in step 100, the type of component to be mounted is read from the storage unit 44 and specified. Next, at step 101, the nozzle 12 is moved to the component position on the component supply unit 27 by the XY driving device 26. In step 102, the nozzle 12 is lowered, in step 103, the chip component 11 is adsorbed, and in step 104, the chip component 11 is adsorbed and raised. Next, in step 105, the nozzle 12 is moved to the mounting device on the circuit board 28, the upper limit value h3 of the thickness of the chip component 11 is stored in step 106, and the thickness data of the specified component is stored in the storage portion 44 in step 107. More specifically, the lower limit value h2 of the thickness of the chip component 11 is read. In step 108, the nozzle 12 descends to mount the chip component 11, and then step 109
Measure the distance h1 between the upper surface of the substrate and the lower surface of the nozzle. Step
At 110, the sizes of h1 and h2, h3 are compared, and the process proceeds to step 111 and step 114.

In step 114, when it is determined in step 110 that the mounting of the component is not normal, the nozzle 12 rises and the error process of step 115 is performed. Step 111 is a case where component mounting is normal, and the nozzle 12 moves up. In step 112, it is determined whether or not all the circuit boards have been mounted. If completed, the operation is ended, and if not completed, the process proceeds to step 113.
In step 113, the nozzle 12 is moved to the position of the next component to be mounted, and the process returns to the first step 102.

The differential transformer 17 used in the present embodiment may be an optical length measuring device, and it is essential only that the distance between the lower surface of the nozzle 12 and the circuit board 28 be measured.

EFFECTS OF THE INVENTION As described above, the present invention measures the height of a chip component mounted when mounting chip components of different sizes corresponding to a plurality of types, and measures the measured value and the variation in the thickness of the selected chip component. Since the mounting of the component is directly confirmed by comparing with the range of 1), it is possible to provide a mounting method with highly reliable mounting detection and flexibility.

[Brief description of drawings]

FIG. 1 is a flow chart of one embodiment of the method of the present invention, FIG. 2 is a perspective view of an apparatus for carrying out the method, FIG. 3 is a side view of the main part, and FIGS. ) Is an enlarged view showing a mounted state of the chip component in the same embodiment, FIG. 5 is a control block diagram of the apparatus, and FIGS. 6A to 6D are explanatory views of a chip component suction state. 11 …… Chip part, 12 …… Nozzle, 13 …… Slide shaft, 17 …… Differential transformer, 18 …… Mover, 20 …… Solenoid, 23 …… Linear motor, 25 …… Position sensor, 26…
... XY drive, 44 ... storage section.

 ─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-55-162299 (JP, A) JP-A-50-126453 (JP, A) JP-A-49-115571 (JP, A) JP-A 61- 64200 (JP, A)

Claims (2)

[Claims] 1. A step of specifying a type of a component to be mounted and mounting the electronic component on a circuit board, and a step of mounting the electronic component on a lower surface of a component holding portion for holding the electronic component and the circuit board. The step of measuring the distance, the step of selecting and reading the data of the thickness of the mounted electronic component from the thickness data of the plurality of electronic components stored in the storage unit in advance, and the step of measuring the thickness of the read electronic component A method of mounting an electronic component, comprising: comparing the data with the measured value to determine whether the electronic component is properly mounted. 2. The electronic device thickness data according to claim 1, wherein the thickness data includes an upper limit value and a lower limit value, and the upper limit value and the lower limit value are compared with the measured value in the determination step. The electronic component mounting method that confirms the mounting by doing.