TW201734436A - Vision inspection method - Google Patents

Abstract

The present invention relates to a device handler and, more particularly, to a device handler that conducts visual inspection for a device, and a visual inspecting method. The present invention discloses a visual inspecting method which relates to a visual inspecting method for conducting visual inspection on a plurality of spherical protruding parts (1a) of a device (1) which has the plurality of protruding parts (1a) formed on a surface thereof, the method being characterized by comprising: an image acquiring step of moving relative to a surface of the device (1), irradiating a slit light, having a first angle of incidence of light with respect to the surface of the device (1) which is greater than 0 DEG and less than 90 DEG, onto the surface of the device (1), measuring the height on the surface of the device (1) using the optical triangulation method, and simultaneously, acquiring a first image for the surface of the device (1) irradiated by the slit light; and a slit light analyzing step of designating a position at the maximum height measured in the image acquiring step, within a region in which a pixel value in pixel units is equal to or greater than a preset value from the first image acquired in the image acquiring step, as a peak position of the protruding parts (1a).

Description

Visual inspection method

The present invention relates to a visual inspection method, and more particularly to a visual inspection method for performing visual inspection on an element.

The semiconductor component is shipped after being loaded on a customer tray or the like through a semiconductor process, a sawing process, or the like. Here, each process performs visual inspection or the like to improve the pass rate and reliability after shipment.

On the other hand, the visual inspection of the semiconductor element is to detect whether the appearance state of the semiconductor element and the surface state are acceptable, such as whether the lead or the ball grid is damaged, cracked, or scratched. Wait.

On the other hand, the detection of the appearance state and the surface state of the semiconductor element as described above is increased, and depending on the detection time and the configuration of each module, the time for performing the overall process and the size of the device are affected.

In particular, the device is configured such that one or more modules for mounting a wafer, a tray, and the like on which a plurality of components are mounted, visual inspection of each component, and an unloading module according to the detection result after the detection, the device The size varies.

Also, the size of the device limits the number of component processing devices that can be disposed within the component detection line, or the component processing device is set according to the amount that has been set in advance, affecting the installation cost for the production component.

SUMMARY OF THE INVENTION An object of the present invention is to provide a visual inspection method which can improve the reliability of visual inspection of a protruding portion such as a ball end formed on a surface of a component by understanding the above-described problems.

The present invention has been made in order to achieve the object of the present invention as described above, and discloses a visual detecting method for performing visual inspection on a plurality of spherical projections 1a formed on the surface of the element 1, characterized in that Including: an image acquisition step of irradiating slit light to the surface of the element 1 while relatively moving relative to the surface of the element 1, and measuring the height on the surface of the element 1 by optical triangulation while Obtaining a first image of a surface of the element 1 that illuminates the slit light, wherein the slit light is irradiated on a surface of the element 1 to form a first incident angle greater than 0° and less than 90°; And a slit light analysis step of, in the first image acquired by the image acquisition step, the height measured by the image acquisition step in an area above the value set in advance by the pixel unit value The highest position is designated as the vertex position of the protrusion 1a.

The projection 1a is preferably a ball end.

The slit light is preferably a monochromatic light.

The visual inspection method according to the present invention has the advantage that when the protrusion in the surface of the element, in particular the vertex position of the ball end, is detected, the slit light is irradiated onto the surface of the element and from the image irradiated to the element In the region having the pixel value equal to or greater than the value set in advance, the highest position of the height measured by the irradiation slit light is designated as the vertex position of the protruding portion, and the reliability of the repeated visual inspection and the visual detection speed can be remarkably improved.

1‧‧‧ components

1a‧‧‧Protruding

410‧‧‧Visual Inspection Module

710‧‧‧Two-dimensional visual inspection department

711‧‧‧First Light Source Department

712‧‧‧First Image Acquisition Department

720‧‧‧Three-dimensional visual inspection department

721‧‧‧Second light source department

722‧‧‧Second Image Acquisition Department

1 is a conceptual diagram showing an example of a visual inspection module for performing a visual inspection method according to the present invention.

2 is a plan view showing the configuration of the visual inspection module of FIG. 1.

Fig. 3a is a conceptual diagram showing a modification of the visual inspection module of Fig. 1.

Figure 3b is a plan view showing the configuration of the visual inspection module of Figure 3a.

Fig. 3c is a conceptual diagram showing a modification of the visual inspection module of Fig. 3a.

4a to 6b are diagrams showing a process of performing a visual inspection method according to the present invention, which is a conceptual diagram showing changes in slit light according to the position of the protrusion; FIGS. 4a and 4b are diagrams showing the apex passing through the protrusion. Fig. 5a and Fig. 5b are views showing the irradiation pattern of the spliced light of the apex of the protruding portion; Figs. 6a and 6b are diagrams showing the illuminating pattern of the slanted light after passing through the apex of the protruding portion; surface.

Fig. 7 is a schematic view showing the relationship between the height of the projection measured by the execution of the visual inspection method according to the present invention and the height of the actual projection.

Hereinafter, a visual inspection method according to the present invention will be described below with reference to the accompanying drawings.

The visual inspection method according to the present invention is executed by the visual inspection module 410, and an image of the appearance of the surface of the element 1 or the like is acquired by a camera, a scanner or the like.

Here, the component 1 is an element that performs a semiconductor process as a wafer level wafer scale package (WL-CSP: Wafer level chip scale pacake), an SD memory, a flash memory, a CPU, etc., as long as a ball grid is formed on the surface. The components of the portion 1a can be the component 1.

The visual inspection module 410 has various structures as a structure for performing visual inspection on the element 1.

As an example, the visual inspection module 410 can have various configurations as a structure for acquiring an image of the appearance of the surface of the element 1 by a camera, a scanner, or the like.

Here, the image acquired by the visual inspection module 410 is applied to visual inspection, which is detected by a program or the like after analyzing the image.

On the other hand, the visual inspection module 410 can have various configurations depending on the type of visual detection. In particular, it is preferable that both the two-dimensional visual inspection and the three-dimensional visual inspection can be performed.

As an example, the visual detection module 410 may include a two-dimensional visual detection unit 710 including a first image acquisition unit 712 and a first light source unit 711, which is acquired for two-dimensional visual inspection. An image of the surface of the element 1 , the first light source unit 711 illuminates the surface of the element 1 for image acquisition by the first image acquisition unit 712 ; the three-dimensional visual detection unit 720 includes a second image acquisition unit 722 and The second light source unit 721 acquires an image of the surface of the element 1 for performing three-dimensional visual inspection, and the second light source unit 721 pairs the element 1 for image acquisition by the second image acquisition unit 722 The surface is illuminated.

In particular, the visual inspection module 410 can have various configurations depending on the configuration and arrangement of the two-dimensional visual inspection unit 710 and the three-dimensional visual detection unit 720.

First, the visual inspection module 410 may have the same configuration as that of the embodiment of the Korean Laid-Open Patent Publication No. 10-2010-0122140 and FIGS. 2a and 2b.

Here, the second light source section 721 of the three-dimensional vision detecting section 720 may have various structures, and monochromatic light such as laser light, white light, or the like may be used.

In particular, when the three-dimensional shape of the object to be measured is small, since the scattering of the laser is large, it is difficult to measure, and it is preferable to use white light with less scattering.

Further, the second light source unit 721 of the three-dimensional vision detecting unit 720 is preferably irradiated on the surface of the element 1 in a slit shape (ie, slit light), including: an optical fiber that transmits light from the light source; and is connected to the optical fiber. The slit-shaped light is irradiated onto the slit portion of the surface of the element 1.

On the other hand, when the size of the element 1 as the measuring object is large, there is a three-dimensional measurement in which the height of the protruding portion such as the ball end, the unevenness, and the like on the surface of the element 1 is difficult to be performed by one camera (scanner).

According to this, the three-dimensional visual detection section 720 can include two or more second image acquisition sections 722.

At this time, the three-dimensional vision detecting unit 720 may include the light source unit 721 respectively corresponding to the second image acquiring unit 722, and may include one light source unit 721 and symmetrically arranged with the light source unit 721 as a reference point as shown in FIGS. 3a and 3b. A pair of second image acquisition sections 722.

Further, the configuration of the visual inspection module 410 is such that the arrangement of the three-dimensional visual inspection unit 720 and the two-dimensional visual detection unit 710 is superimposed on each other with reference to the moving direction of the element 1 as shown in FIGS. 1 and 2, or The two-dimensional visual inspection unit 710 and the three-dimensional visual detection unit 720 can be sequentially disposed as shown in FIGS. 3a to 3c.

In particular, as shown in FIG. 3b, when the two-dimensional vision detecting unit 710 and the three-dimensional visual detecting unit 720 are sequentially disposed, the visual detecting module 410 arranges a pair in the moving direction of the element 1 in the three-dimensional visual detecting unit 720. The second image acquisition unit 711 can arrange the light source unit 721 between the pair of second image acquisition units 722.

Further, as shown in FIG. 3c, when the two-dimensional vision detecting unit 710 and the three-dimensional visual detecting unit 720 are sequentially disposed, the visual detecting module 410 sequentially arranges the third direction visual detecting unit 720 in accordance with the moving direction of the element 1. The second image acquisition unit 722 and the light source unit 721.

As shown in FIGS. 4a to 6b, the visual inspection method according to the present invention is characterized in that visual inspection is performed on the plurality of projections 1a for the element 1 in which a plurality of spherical projections 1a are formed on the surface.

Further, the visual inspection method according to the present invention includes an image acquisition step of irradiating the slit light to the surface of the element 1 while the surface of the element 1 is relatively moved, and measuring the height on the surface of the element 1 by optical triangulation, Simultaneously acquiring a first image of a surface of the element 1 that illuminates the slit light, wherein the slit light is formed on the surface of the element 1 to form a first incident angle greater than 0° and less than 90°; and a slit light analysis step, In the first image acquired by the image acquisition step, the highest position of the height measured by the image acquisition step is designated as the protrusion 1a in the area of the pixel and above the value set by the pixel value in advance. Vertex position.

The image acquisition step can be performed by various methods, wherein the image acquisition step is as follows: slit light is irradiated onto the surface of the element 1 while moving relative to the surface of the element 1, and the element 1 is measured by optical triangulation The height on the surface simultaneously acquires a first image of the surface of the element 1 irradiated with the slit light, wherein the slit light is irradiated on the surface of the element 1 to form a first incident angle of more than 0° and less than 90°.

Here, the slit light can be identified by the illuminance value, and monochromatic light can be used, for example, white light is preferred.

Further, the height on the surface of the element 1, that is, the height of the projection 1a such as the ball end, the unevenness, or the like formed on the surface of the element 1 can be measured by optical triangulation using the slit light irradiated.

However, as shown in FIG. 7, even if the apex is high, the height of the protruding portion 1a has a maximum value at a position passing through the apex of the protruding portion 1a due to the distortion of the slit light.

This is because the distortion of the light when the slit light is irradiated onto the protruding portion 1a, the position of the apex of the protruding portion 1a is measured as a factor of error by the distortion of the light, and there is a problem that the detection reliability is lowered when the visual inspection is repeated.

In particular, the ideal shape of the projection 1a such as the ball end is that the distortion of the light is maximized in the case where a part of the surface is damaged when the partial shape of the ball is realized, and becomes the apex of the projection 1a at the time of visual inspection. The cause of the position error and the reliability of the detection at the time of repeated execution can be greatly reduced.

According to this, the present invention measures the height on the surface of the element 1 by the optical triangulation by the irradiation of the slit light, and the image of the element 1 irradiated with the slit light minimizes the measurement error of the visual detection, although repeated execution Visual inspection improves the reliability of the test results.

According to this, the image acquisition step is as follows: the slit light is irradiated onto the surface of the element 1 while moving relative to the surface of the element 1, and the height on the surface of the element 1 is measured by an optical triangulation while acquiring the A first image of the surface of the light-irradiated element 1 is slit, wherein the slit light is formed on the surface of the element 1 to form a first incident angle greater than 0° and less than 90°.

Here, the height on the surface of the element 1 is preferably measured by mapping to a position corresponding to more than one pixel of the first image, which is an image acquired with respect to the surface of the element 1.

The slit light analysis step may be performed by various methods, wherein the slit light analysis step is as follows: in the first image acquired from the image acquisition step, in a region in which the pixel value is higher than a value set in advance in units of pixels The highest position of the height measured in the image acquisition step is designated as the vertex position of the protrusion 1a.

Specifically, in the first image acquired by the image acquisition step described above, an effective area in which the pixel value is equal to or greater than the value set in advance is set.

Then, the maximum position of the height measured from the image analysis step is designated as the vertex position of the protruding portion 1a in the effective area.

Here, the slit light passes through the apex of the protruding portion 1a, and the height H measured by the optical trigonometry is also increased, but the pixel value (illuminance) corresponding to the slit light on the surface of the element 1 irradiated with the slit light has Relatively small value.

In view of this, the slit light analysis step is to calculate a pixel value equal to or greater than a value set in advance from the first image acquired in the image acquisition step, thereby calculating the width of the slit light irradiated on the surface of the element 1. The maximum position of the calculated slit light width is designated as the vertex position of the protruding portion 1a.

On the other hand, the slit light analysis step maps the size of the first image and the element 1 acquired from the image acquisition step and the pixel size of the first image.

Then, if the actual position on the element 1 and the pixel position of the first image are used, the actual position on the element 1 can be calculated from the pixel position of the calculated maximum position of the slit light width.

On the other hand, the visual detecting method according to the present invention can be executed by the three-dimensional visual detecting unit 720 described above, but is not limited to the visual detecting module shown in FIGS. 1 to 3c, as long as the slit can be used. A visual inspection module that performs three-dimensional vision detection by light, and any module can perform the method.

The above is merely illustrative of the preferred embodiments of the present invention, and the scope of the present invention is not limited to the specific embodiments, but may be appropriately changed within the scope of the claims.

1a‧‧‧Protruding

Claims (3)

A visual inspection method for performing visual inspection on a plurality of spherical protrusions (1a) formed on a surface of an element (1), characterized by comprising: an image acquisition step with respect to the element (1) The surface is irradiated with light to the surface of the element (1) while being relatively moved, and the height on the surface of the element (1) is measured by optical triangulation while acquiring the light for illuminating the slit light a first image of the surface of the element (1), wherein the slit light is formed on the surface of the element (1) to form a first incident angle greater than 0° and less than 90°; and a slit light analysis step, In the first image acquired by the image acquisition step, the highest position of the height measured by the image acquisition step in an area above the value set in pixels and the pixel value is set in advance Designated as the vertex position of the protrusion (1a). The visual inspection method according to claim 1, wherein the protruding portion (1a) is a ball end. The visual inspection method according to claim 1, wherein the slit light is monochromatic light.