CN101614680A - Defect detecting device and method - Google Patents

Abstract

The invention provides a kind of defect detecting device that can detect the short transverse position of defective.Glass plate (99) (v) moves, comes the position (d) of testing platform (2) by operating position pick-up unit (4) with constant speed.Via mask (10) light is incided the glass plate (99) from lighting device (1) at a predetermined angle obliquely, detect the reflected light that reflects by glass plate (99) lower surface by image detection device (3).Utilize incident light and reflected light to detect defective, measure its time interval, controller (5) according to described predetermined angular, predetermined speed (v) and the short transverse position of time interval computing defective.

Description

Defect detecting device and method

Technical field

The present invention relates to defect detecting device.

Background technology

At the exposure device of the manufacturing that is used for printed circuit board etc., the photomask of describing exposing patterns is bearing in and sees through the on glass of exposure light.

In exposure device, the glass that uses in the contact exposure apparatus that photomask and substrate are close to is thick and big, therefore may comprise bubble and foreign matter in inside.

These bubbles and foreign matter be according to the height and position of the thickness direction of glass, influences difference to what exposure caused.For example, in when exposure, exposure object is the lower face side that the resist face of substrate is positioned at glass, and when bubble and foreign matter were in position near lower glass surface, during promptly near the resist face, the harmful effect that brings to exposure became big.Otherwise when having defective near surface on glass, harmful effect diminishes.

In order to detect the defective and the foreign matter of this glass inside, shown in following patent documentation 1～5, various schemes have been proposed.

[patent documentation 1] Japanese kokai publication hei 11-264803 communique

[patent documentation 2] TOHKEMY 2005-156416 communique

[patent documentation 3] TOHKEMY 2005-201887 communique

[patent documentation 4] TOHKEMY 2006-49078 communique

[patent documentation 5] TOHKEMY 2006-112955 communique

But in existing arbitrary structures, all there is following problem: can not detect the short transverse position of defective and foreign matter, the correctly influence that brings to exposure of defect recognition and foreign matter.

Summary of the invention

The objective of the invention is to solve above-mentioned prior art problems.

In order to achieve the above object, defect detecting device of the present invention is characterised in that, this defect detecting device has: lighting device, it shines this inspection light at a predetermined angle obliquely at seeing through the inspection object of checking light, and this inspection light has incident light that incides inspection object lower surface and the reflected light that is reflected by inspection object lower surface; Mobile device, it makes this inspection object and described lighting device relatively move at a predetermined velocity favouring on the described inspection direction of light; Pick-up unit, it detects the defective of described inspection object by described incident light and reflected light; Time interval pick-up unit, it detects based on the defects detection of described incident light and based on the time interval between the described catoptrical defects detection; And arithmetic unit, it is according to the short transverse position of described predetermined angular, described predetermined speed and the described defective of described time interval computing.

By said structure, can detect the defective of checking object and the position of detecting the short transverse of this defective.In addition, therefore use can will not be defective attached to detections such as the dusts of checking the object lower surface by the reflected light of checking the reflection of object lower surface.

In addition, described pick-up unit can constitute to have described inspection object lower surface is carried out the imaging lens of imaging and is arranged on CCD on the imaging surface of this imaging lens.According to this structure, check that the inspection sensitivity of object upper surface side is relatively low, can reduce influence attached to the dust of checking the object upper surface etc.

In addition, described pick-up unit can also constitute the device that further has the aperture of adjusting described imaging lens, adjusts the flaw detection sensitivity of checking object inside by the adjustment of this aperture.

According to defect detecting device of the present invention and method, can detect the defective of checking object and the position of detecting the short transverse of this defective.In addition, can suppress influence attached to the lip-deep dust of checking object etc.

Description of drawings

Fig. 1 is the skeleton diagram of expression an embodiment of the invention.

Fig. 2 is the key diagram of the action of expression an embodiment of the invention.

Fig. 3 is the key diagram of the action of expression an embodiment of the invention.

Fig. 4 is the key diagram of the action of expression an embodiment of the invention.

Fig. 5 is the key diagram of the action of expression an embodiment of the invention.

Fig. 6 is the process flow diagram of the action of expression an embodiment of the invention.

Symbol description

1 lighting device; 2 worktable; 3 image detection devices; 4 operating position pick-up units; 5 controllers; 10 masks; 15 input paths; 16 reflected light paths; 20 mobile devices; 30 imaging lens; 31 linear CCDs; 32 image-input devices; 33 image processing apparatus; 50 displays; 80 defectives; 97 surfaces on glass; 98 lower glass surface; 99 glass plates.

Embodiment

Below, embodiments of the present invention are described with reference to the accompanying drawings.

In Fig. 1, check that object is that glass plate 99 is placed on the worktable 2, move with constant speed v on the Y direction shown in the arrow by mobile device 20.

Position d by operating position pick-up unit 4 testing platforms 2.

Above glass plate 99, be provided with lighting device 1, make light inject glass plate 99 obliquely via mask 10.

On the position relative with lighting device 1, be provided with image detection device 3, detect reflected light by the reflection of glass plate 99 lower surfaces.

Lighting device 1 is to be the wire diffused illumination of irradiation Line of light on the directions X at the Width of glass plate 99 (direction vertical with moving direction), be provided with mask 10 as shown in Figure 2, shine linear diffused illumination light with incident angle θ with respect to the moving direction of glass plate 99.According to this structure, the illumination of lighting device 1 is to tilt to inject glass plate 99 with incident angle θ, only detects from the light of glass plate 99 reflections.

In addition, glass plate 99 moves with respect to lighting device 1, but as long as glass plate 99 and lighting device 1 relatively move, and also can be to make the structure that lighting device 1 moves or make glass plate 99 and structure that lighting device 1 both sides are all mobile.

As shown in Figure 2, illumination process input path 15 and reflected light path 16 from lighting device 1 are received by linear CCD 31.

Promptly sentence refraction angle φ refraction and, sentence refraction angle φ refraction on glass surperficial 97 again on glass surperficial 97 with the wire illumination that incident angle θ incides the glass plate 99 in lower glass surface 98 reflections from lighting device 1 and mask 10.Assemble by 30 pairs of these reflected light of imaging lens that the front focus position is positioned on the lower glass surface 98, receive and detect by linear CCD 31.

Accept predetermined process via image-input device 32 at image processing apparatus 33 places by linear CCD 31 detected images, be presented on the display 50 by controller 5.

By Fig. 3 detection when having air blister defect 80 in the glass plate 99 of refractive index n is described.

Glass plate 99 is placed on the worktable 2, moves to right with speed v in Fig. 3.Shown in Fig. 3 (A), defective 80 is at first by input path 15, and this moment, the detected value of linear CCD 31 reduced, and finished the first time of defective 80 and detected.

Next shown in Fig. 3 (B), defective 80 is finished the detection second time of defective 80 equally by reflected light path 16 by linear CCD 31.

Controller 5 is according to this testing result, and following calculating defective 80 is apart from the height h of lower glass surface 98.In addition, the time that can reduce according to the output of linear CCD 31 and the movement speed v size of calculating defective 80.

For the first time the position of the position of the defective 80 that detects and the defective 80 that detects for the second time is expressed as d=tv in the Y direction apart from d.Herein, t is the detection first time of defective 80 and the time interval between the detection second time, counts in controller 5.

Herein, according to Si Nieer (Snell) law, the refraction angle φ that establishes the light of incident angle (viewing angle) when being n for θ and the refractive index of establishing glass plate 99 is expressed from the next.

sinθ＝nsinφ

At this moment, the height h of defective 80 and be apart from the pass of d:

2htan θ=d, so the height h of defective 80 is expressed from the next.

According to following formula as can be known defective 80 height h and interval time t to occur proportional.That is, defective 80 is short more the closer to 98 time t of lower glass surface, and is long more the closer to surperficial 97 time t on glass.

[formula 1]

$h=\frac{\mathrm{<figure-callout\; id="2"\; label="tv"\; filenames="A2009100081940009H1.png"\; state="\{\{state\}\}">tv</figure-callout>}}{2\tan \left({\sin }^{-1}\left(\frac{\sin \mathrm{\&theta;}}{n}\right)\right)}$

Fig. 4 illustrates the position of defective 80 and is presented at image on the display 50 by what controller 5 obtained.

As mentioned above, the signal intensity from linear CCD 31 when having defective 80 diminishes, so defective 80 is shown as dark portion on display 50.

Apart from the height of lower glass surface 98 be defective 80a, 80b, 80c, 80d, the 80e of h1, h2, h3 on display 50, be shown as have d1, the dark portion of the paired appearance of d2, d3, d4 distance.As mentioned above, h is high more for height, and the interval d of dark portion is big more.

Fig. 5 illustrates the relation of the allowing of the height h of defective 80 and size and this defective 80/between not allowing.Bubble defectives 80 such as (foreign matters) is in more near lower glass surface 98, the low position of height h, just brings harmful effect to exposure more, therefore is made as and does not allow.And the size of defective 80 is big does not more then allow more.

As defective 80d, height h is during more than or equal to the thickness of glass plate 99, and this defective 80d is judged as surperficial 97 dust on glass.

Promptly when the thickness of establishing glass plate 99 be T and the interval d4 of check pattern when becoming following formula, be used as by attached to the pattern that dust caused on glass surperficial 97, be judged to be normal.

[formula 2]

${\mathrm{<figure-callout\; id="4"\; label="d"\; filenames="A2009100081940009H1.png"\; state="\{\{state\}\}">d</figure-callout>}}_4\&GreaterEqual;2T\tan \left\{{\sin }^{-1}\left(\frac{\sin \mathrm{\&theta;}}{n}\right)\right\}$

In addition, when as defective 80c or 80e, being in the position of close lower glass surface 98, can not become the pattern of paired appearance sometimes.

For example, defective 80c is circular bubble as shown in Figure 4, when establish its size (diameter) for Sx, establish check pattern be spaced apart d3 the time, under the situation of Sx＞d3, two images can not be separated.

When having produced this pattern, expression defective 80 is also bigger near lower glass surface, its size, therefore brings dysgenic possibility height to exposure.Therefore, the size on the direction that will be vertical with the moving direction (Y direction) of substrate is considered as size Sx, height h is considered as 0, judges according to Fig. 5 and allows/do not allow.

Flowchart text action according to Fig. 6.

At by linear CCD 31 and image-input device 32 detected depth patterns, in image processing apparatus 33, threshold value is set, carry out binaryzation and obtain two-value pattern (step S1), demarcate (labeling) (step S2) at this two-value pattern.

(Sx Sy) carries out instrumentation (step S3), at each pattern, at the enterprising line search of substrate moving direction (Y direction), seeks the pattern (step S4) of the roughly the same or same size of size to the centre coordinate size of calibrated each pattern.With the region of search be located at thickness with glass plate 99 suitable apart from the d4.

When having the pattern of same size (step S5), ask for the interval d of the Y direction of these patterns, calculate their height h (step S6).

The pattern height h that obtains, size (for example mean value of XY direction) are contrasted with judgment standard shown in Figure 5, judge and allow/do not allow (step S7, S8, S9).

In step S5, be considered as not having same pattern but separately during pattern, the size Sx of directions X is used as size, establishes height h is 0 (step S10), contrasts judgment standard shown in Figure 5 equally, judges and allows/do not allow (step S7, S8, S9).

Past more lower glass surface 98 is subjected to optical range more little, even the defective 80 of same size, past more lower glass surface 98 light quantities change more greatly, and detection sensitivity increases.Therefore, even on glass surperficial 97, be attached with dust etc., be that the danger of defective 80 is also less by error-detecting.

And therefore the dust of lower glass surface 98 does not exist situation about being detected to reflected light not influence fully.

Claims (3)

1. a defect detecting device is characterized in that, this defect detecting device has:

Lighting device, it shines this inspection light at a predetermined angle obliquely at seeing through the inspection object of checking light, and this inspection light has incident light that incides inspection object lower surface and the reflected light that is reflected by inspection object lower surface;

Mobile device, it makes this inspection object and described lighting device relatively move at a predetermined velocity favouring on the described inspection direction of light;

Pick-up unit, it detects the defective of described inspection object by described incident light and reflected light;

Time interval pick-up unit, it detects based on the defects detection of described incident light and based on the time interval between the described catoptrical defects detection; And

Arithmetic unit, it is according to the short transverse position of described predetermined angular, described predetermined speed and the described defective of described time interval computing.

2. defect detecting device according to claim 1, wherein, described pick-up unit has:

The imaging lens that described inspection object lower surface is carried out imaging; And

Be arranged on the CCD on the imaging surface of this imaging lens.

3. a defect inspection method is characterized in that, this defect inspection method may further comprise the steps:

At seeing through the inspection object of checking light, shine inspection light at a predetermined angle obliquely from lighting device, this inspection light is incided check the object lower surface, and by the step of checking the reflection of object lower surface;

Make this inspection object and described lighting device favour the step that relatively moves at a predetermined velocity on the described inspection direction of light;

The light by described incident and the light of reflection detect the step of the defective of described inspection object;

Detection is based on the defects detection of the light of described incident and based on the step in the time interval between the defects detection of the light of described reflection; And

Step according to the short transverse position of described predetermined angular, described predetermined speed and the described defective of described time interval computing.

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