JP3419287B2 - Electronic component mounting state inspection method and mounting state inspection device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component mounting state inspection method for inspecting a mounting state of an electronic component mounted on a board, and particularly to mounting an electronic component having a structure in which light is difficult to diffuse and reflect. Condition inspection method and packaging
The present invention relates to a condition inspection device .

[0002]

2. Description of the Related Art After mounting an electronic component such as a chip on a substrate, a mounting state inspection is performed to inspect whether the electronic component is properly mounted. As a method of this mounting state inspection, there is known a method of inspecting the position and orientation of the electronic component by optically measuring the height of the electronic component mounted on the substrate. In this method, the measurement point set at the position of the electronic component is irradiated with light from above, and the diffused reflected light from the measurement point is received by a photodetector such as a position detection element to obtain the height of the measurement point. Is.

[0003]

Some electronic components, such as glass-coated chips, have a structure in which the upper surface absorbs light and is difficult to diffuse and reflect. Most of these electronic components are absorbed even when the measurement point set on the upper surface is irradiated with light. Therefore, the amount of reflected light diffusely reflected and received by the photodetector is small. Therefore, when the upper surface of the electronic component has a structure in which light is difficult to be diffused and reflected, the photocurrent required for height measurement cannot be obtained, and the correct height measurement value cannot be obtained. As described above, in the conventional mounting state inspection method using diffused light, there is a problem in that an electronic component having an upper surface having a structure that is unlikely to be diffused and reflected cannot be an inspection target. Such a problem also occurs in an electronic component having a mirror surface that totally reflects light, and is a problem common to electronic components having a structure in which it is difficult to diffusely reflect light.

Therefore, the present invention provides a mounting state inspection method and a mounting state inspection device for an electronic component, which can inspect the mounting state of the electronic component even if the upper surface of the electronic component on the mounting substrate is difficult to diffuse and reflect. The purpose is to provide.

[0005]

According to a method of inspecting a mounting state of an electronic component of the present invention, a measuring point set at an electronic component position on an upper surface of a substrate on which the electronic component is mounted is irradiated with light from above, A mounting state inspection method for an electronic component, which inspects a mounting state of an electronic component by receiving diffused reflected light from a measurement point by a photodetector, wherein an electronic component having a structure that hardly diffuses and reflects light is mounted. If the light detector irradiates a position that seems to exist, and the diffuse reflected light of a predetermined intensity or more is not received by the photodetector, it is determined that an electronic component having a structure that is difficult to diffuse and reflect the light is mounted at that position. I chose

According to the present invention, light is applied to a position where an electronic component having a structure that hardly diffuses and reflects light is considered to be mounted, and diffuse reflected light having a predetermined intensity or more is not received by the photodetector. For example, by determining that an electronic component having a structure that hardly diffuses and reflects light is mounted at that position, the mounting state can be inspected even for an electronic component that has a structure that hardly diffuses and reflects light. .

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. 1 is a block diagram showing the configuration of an electronic component mounting state inspection device according to an embodiment of the present invention, FIG.
3 is a flowchart showing an operation of the electronic component mounting state inspection device.

First, the construction of an electronic component mounting state inspection apparatus will be described with reference to FIG. In FIG. 1, a substrate 2 is placed on an XY table 1. An electronic component 3 (glass coated component) having a glass coat portion 3a on its upper surface and an electronic component 20 (normal component) having no glass coat are mounted on the substrate 2. The structure of the upper surface of the electronic component 3 is
It has a structure that makes it difficult to diffusely reflect light. A laser generator 4 is arranged above the XY table 1. The laser generator 4 irradiates the substrate 2 on the XY table 1 with laser light. By driving the XY table 1, the substrate 2
It is possible to move the electronic components 3 and 20 mounted on the laser to the irradiation position of the laser generator 4.

A scanner 5 is arranged below the laser generator 4, and the scanner 5 scans the laser light emitted from the laser generator 4 in accordance with a set pattern. A photodetector 6 is arranged diagonally above the substrate 2. The photodetector 6 includes a lens 7 and a position detection element (PSD) 8. The laser light emitted from the laser generator 4 is applied to the measurement points set at the positions of the electronic components 3 and 20 by the scanner 5, and the diffuse reflected light from the measurement points is received by the photodetector 6. P through the lens 7
The light incident on SD8 is output as a current.

Next, the structure of the control system will be described. XY
The table controller 10 controls the operation of the XY table 1. The current detector 11 detects the output current of the PSD 8.
The light quantity control unit 12 controls the quantity of laser light emitted from the laser generator 4. The scanner controller 13 is the scanner 5
Control the scanning pattern and range.
The control unit 14 is a CPU, and integrally controls each unit of the mounting state inspection device. The glass-coated component determination program storage unit 15 stores a determination program corresponding to the electronic component 3 having a glass-coated portion on the upper surface, that is, a determination program in the case of the electronic component 3 in which a height measurement value by diffuse reflection light cannot be obtained. To do. The normal component determination program storage unit 16 is a normal electronic component 20 that does not have a glass coat unit.
The determination program based on the height measurement for the is stored.

The component mounting position information storage unit 17 stores information on the types and mounting positions of electronic components mounted on the board 2 to be inspected. Based on this component mounting position information, the control unit 14 determines whether the electronic component to be inspected is the electronic component 3 having the glass coat portion 3a or the normal electronic component 20, selects a determination program, and selects the determination program. Based on the inspection. The determination result storage unit 18 is
The determination result for each electronic component of the board 2 to be inspected is stored.

This electronic component mounting state inspection apparatus is configured as described above, and the mounting state inspection method will be described below with reference to the flow chart of FIG. The flow shown here is performed for the electronic component 3 mounted on the substrate 2 to be inspected and having the glass coat portion 3a on the upper surface.

That is, in the mounting state inspection of the mounting board, the XY table 1 is driven on the basis of the position information of the electronic components 3 and 20 stored in the component mounting position information storage unit 17 so that each electronic component is sequentially generated by the laser generator 4. The mounting state is inspected by arranging the glass coat component determination program storage unit 15 from the glass coat component determination program storage unit 15 if the electronic component to be inspected is the electronic component 3 having the glass coat unit 3a. The data is read out, and the inspection and determination are performed according to the flow of FIG.

First, the scanning area on the electronic component 3 is set in the scanner control unit based on the data (type, size of the glass coat portion, etc.) of the electronic component 3 (ST1). Next, it is judged whether or not the set scanning is completed (ST2), and if it is not completed, the spot of the laser irradiation light is moved to the next measurement point (ST3), and the current detection unit 11 causes the PSD 8 The current is detected (ST4). Next, it is determined whether or not the detected current is valid, that is, whether or not diffuse reflected light having a predetermined intensity or more that is set is detected (ST5).

The fact that the current detected here is "effective" means that the current has an intensity with which a normal height measurement value can be obtained. Then, if the detected current is not effective, that is, if the diffuse reflection light from the measurement point is equal to or less than the predetermined intensity, it is determined that the measurement point is the glass coat portion (ST6). Here, when only one measurement point is set for the electronic component 3 to be inspected, an electronic component having a structure in which it is difficult to diffuse and reflect light, such as the electronic component 3 having a glass coat at that position based on the determination in ST6. 3 can be determined to be implemented.

In this embodiment, the following steps are added to make the determination result more accurate. That is, when the inspection at one measurement point is completed, the process returns to ST2 again, and the determination at ST6 is made by the same inspection for all the measurement points in the scanning region. The ratio of the glass coat portion 3a to the entire scanning region is obtained from these inspection results (ST7). And the required glass coat part 3
If the ratio of a is larger than the threshold value, it is determined that the electronic component 3 having the glass coat portion 3a is surely mounted at the inspection position (ST9). It is determined that the electronic component 3 that the user has is not mounted (ST10). These determination results are stored in the determination result storage unit 18 for each electronic component 3.

As described above, by utilizing the fact that the diffuse reflection light is very small in the structure having the glass coat, the mounting state of the electronic component having the glass coat portion is inspected and the conventional height measurement value is obtained. It can be performed using the conventional mounting state inspection device without going through the steps. In the present embodiment, the glass-coated component has been described as an example of an electronic component having a structure that hardly diffuses and reflects light, but the present invention is also applicable to an electronic component having a mirror surface that almost totally reflects light. Is applicable.

[0018]

According to the present invention, light is emitted from above to a measurement point set at an electronic component position on the upper surface of a mounting board on which electronic components are mounted, and if diffuse reflection light having a predetermined intensity or more is not received. For example, it is determined that an electronic component with a structure that does not diffuse and reflect light is mounted at that position. The mounting state can be inspected using the same inspection device as the mounting state inspection by measurement.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an electronic component mounting state inspection device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the electronic component mounting state inspection device according to the embodiment of the present invention.

[Explanation of symbols]

1 XY table 2 substrates 3 electronic components 3a Glass coat part 4 Laser generator 5 scanner 6 Photodetector 8 PSD 11 Current detector 14 Control unit 20 electronic components

Claims (3)

(57) [Claims] 1. By irradiating light from above onto a measurement point set at an electronic component position on an upper surface of a substrate on which electronic components are mounted, and by receiving diffuse reflected light from the measurement point by a photodetector. An electronic component mounting state inspection method for inspecting a mounting state of an electronic component, which comprises irradiating light to a position where an electronic component having a structure that hardly diffuses and reflects light is considered to be mounted, and diffusing light with a predetermined intensity or more. If the reflected light is not received by a photodetector, it is determined that an electronic component having a structure that hardly diffuses and reflects the light is mounted at that position. 2. An electronic part on an upper surface of a substrate on which electronic parts are mounted.
Irradiate light from above to the measurement point set in the product position
Then, the diffused reflected light from the measurement point is received by the photodetector.
Electronic that inspects the mounting state of electronic components based on height measurement
It is a mounting state inspection device for parts, and is used to diffuse and reflect light.
It seems that electronic components with a pile structure are mounted.
Light is radiated to a position, and diffuse reflected light with a certain intensity or higher is detected.
If it is not received by the instrument, it will diffusely reflect the light to that position.
It is determined that an electronic component with a difficult structure is mounted.
Judgment program and the inspection based on this judgment program.
Of electronic parts characterized by having a control unit for conducting inspections.
Mounting state inspection device. 3. An electronic component mounted on a substrate to be inspected
Stores the component mounting position information related to the type and mounting position
A component mounting position information storage unit, wherein the control unit controls the component
To select the judgment program from the tower position information
The mounting condition inspection device for an electronic component according to claim 2,
Place