CN105157616A - Shadow Moire contour measurement device and calibration method and measurement method thereof - Google Patents

Abstract

The invention provides a shadow Moire contour measurement device and a calibration method and a measurement method thereof. The measurement device comprises red, green and blue linear light sources, a color CCD camera, a grating, and a precision displacement platform. The red, green and blue linear light sources and the color CCD camera are collinearly arranged at one side of the grating and are parallel to the surface of the grating. The grating is arranged on the precision displacement platform. The red, green and blue linear light sources are arranged at one side of the color CCD camera. The invention further provides the calibration method and the measurement method of the shadow Moire contour measurement device. The problem that measurement of a measured object takes a long time and the precision of measurement is not high for the existing phase shift shadow Moire measurement device and the measurement method is overcome.

Description

A kind of shadow moire profilometry device, its scaling method and measuring method

Technical field

The present invention relates to technical field of optical precision measurement, be specifically related to a kind of shadow moire profilometry device, its scaling method and measuring method.

Background technology

Shadow Moire technology of profiling precision is high, has become the one preferred technique that object is heated or stress deformation is measured.And JEDEC high temperature measurement industrial standard also recommends shadow moire to be carry out one of such major technique measured.So far, have the application of shadow Moire technology in IC industry of a large amount of bibliographical informations, and pertinent literature is also constantly emerging in large numbers.These application comprise the topography measurement etc. of the package surface profile measurement of chip, the silicon wafer measurement of planeness and silicon wafer integrated circuit.But continuing the variation that diminishes and design along with Electronic Packaging, new manufacturing process is the measurement requirement that measuring technique proposes online or in place, high precision, full inspection.This feature also requires that the change that existing measuring technique adapts to test product feature improves accordingly, its measurement mechanism is made to have optimum parameter, to obtain high-contrast moiré topography, and in conjunction with phase-shifting technique, reliably automatically extract metrical information etc. without omission ground.But being subject to the restriction of components and parts manufacture level and Measurement Algorithm, traditional shadow Moire measurement mechanism often uses black-white CCD video camera, and is produced the change of measuring visual field phase place by moving grating, and its dephasing processes needs mechanical motion, and process wastes time and energy.Although some device is attempted to introduce phase shift by the light on and off of Time-sharing control Different Light for measuring visual field in addition, but the method can not complete the acquisition of bar graph simultaneously, and it is too strict to light source positioning requirements, light source cannot be realized accurately locate, moreover, its measurement result is subject to the impact of light field change, can not carry out reliable measurements.Another shortcoming of tradition shadow Moire device is that its calibration process needs to make calibrating block, timing signal needs according to the known elevation information of calibrating block, and inverse goes out device parameter, or needs record to measure the light intensity Changing Pattern of visual field point, these class methods realize complicated, can not complete demarcation fast.

Summary of the invention

The object of this invention is to provide a kind of shadow moire profilometry device, its scaling method and measuring method, measure testee the time longer and problem that precision is not high to overcome existing phase shift shadow Moire measurement mechanism and measuring method.

Technical scheme of the present invention is:

A kind of shadow moire profilometry device, described measurement mechanism comprises red, green, blue three line sources, colourful CCD video camera, a grating and a precision displacement platform; Described red, green, blue three line sources and colourful CCD video camera conllinear be arranged at grating side and parallel with grating face; Described grating is arranged on that accurate displacement is flat appears on the stage; Described red, green, blue three line sources are arranged in colourful CCD video camera side.

Described precision displacement platform is manual precision displacement table or electric precision displacement platform.

Described red, green, blue three line sources are arranged in colourful CCD video camera side at equal intervals.

A scaling method for shadow moire profilometry device, comprises the following steps:

Step one, is placed in testee below grating, opens any one monochromatic source in red, green, blue three line sources, by the equidistant moving grating several times of precision displacement platform, and shooting and record phase shift bar graph wherein;

Step 2, use phase shift extraction algorithm determines the phase shift because moving grating produces.

A measuring method for shadow moire profilometry device, comprises the following steps successively:

Step one, grating is adjusted to initial position, and testee is placed in below grating, opens red, green, blue three line sources simultaneously, produce secondary color Moire fringe on testee surface, then colourful CCD video camera absorbs secondary color Moire fringe under single shot condition;

Step 2, is separated the secondary color Moire fringe of picked-up and forms monochromatic Moire fringe, obtain the phase shift moire fringe figure for demodulation testee surface topography;

Step 3, by the data Regularization of step 2 gained, then uses primaries analytic approach to extract and measures phase place;

Step 4, uses de-packaging method to carry out phase unwrapping to the measurement phase place that step 3 is extracted;

Step 5, according to the phase place of measurement sensistivity and expansion, carries out Phase-height mapping, completes measurement.

Beneficial effect of the present invention:

1, measurement mechanism structure of the present invention is simple: the measurement mechanism structure proposed in the present invention adopts colourful CCD video camera, can complete the collection of phase shift bar graph simultaneously, by using R, G, B light source irradiation to measure grating, can complete the phase shift of bar graph simultaneously; Compared with traditional shadow moire, the present invention improves measurement structure, reduces because the diffraction of light and grating surface reflected light are on the impact of fringe contrast and the distribution of light intensity sine; Its installation requirement is low, and does not increase the complicacy of measuring system;

2, the measuring method of testee surface appearance feature of the present invention is simple: under testee is placed in grating, once automatically can complete measurement, improves measuring speed, to adapt to the measurement requirement of online or in place and full inspection; Development, without the phase shift shadow Moire demodulation techniques of imbalance, makes measuring accuracy reach submicron order in comparatively great dynamic range; Object surface appearance measurement can being carried out by this method, can automatically measure testee surface topography, laying the first stone fast for realizing object surface appearance.

3, the present invention is also for device provides a set of scaling method fast: the method does not use calibrating block, only rely on shadow Moire own device, realize quick, the convenient demarcation of measurement sensistivity and structural parameters, the present invention directly can carry out the demarcation of measurement sensistivity in measuring process, improves measurement efficiency;

4, the present invention's application requires low: the present invention does not need the consistance of light source, low to environmental requirement, is applicable to the measurement needs of industrial occasions.

Accompanying drawing explanation

Fig. 1 is measurement mechanism schematic diagram of the present invention;

Fig. 2 is the schematic diagram that measuring method of the present invention is implemented;

In figure, 1-red, green, blue three line sources, 2-colourful CCD video camera, 3-grating, 4-testee.

Embodiment

Below in conjunction with accompanying drawing, the present invention is further detailed, a kind of shadow moire profilometry device as shown in Figure 1, described measurement mechanism comprises red, green, blue three line sources 1, colourful CCD video camera 2, grating 3 and a precision displacement platform; Described red, green, blue three line sources 1 and colourful CCD video camera 2 conllinear be arranged at grating 3 side and parallel with grating face; Described grating 3 is arranged on that accurate displacement is flat appears on the stage, and precision displacement platform is manual precision displacement table or electric precision displacement platform, and precision displacement platform can drive grating 3 to move along the direction in vertical raster face; Described red, green, blue three line sources 1 at equal intervals or approximate be arranged in colourful CCD video camera 2 side at equal intervals.

Introduce the scaling method based on said apparatus below:

See Fig. 2, the optical axis of colourful CCD video camera 2 is perpendicular to grating face, red, green, blue three line sources 1 are equidistantly arranged, the optical centre of colourful CCD video camera 2 and light source center are placed in the distance of distance grating plane h, and first line source and colourful CCD video camera optical center distance are d.

Before actual measurement object surface appearance, first carry out the demarcation of measurement mechanism, this proving operation is the needs when measuring first only, and the concrete steps of scaling method are:

Step one. testee 4 is placed in below grating 3, open any one monochromatic source in red, green, blue three line sources 1, manually precision displacement table or electric precision displacement platform moving grating 1/3rd four fringe spacing are apart from 3 times, and shooting and record phase shift bar graph wherein;

Step 2. use phase shift extraction algorithm determines the phase shift delta because moving grating 3 produces, and according to the phase shift delta determined, obtaining measurement sensistivity S is: in formula, Δ h is the distance of precision displacement platform movement at every turn.

After the staking-out work completing measurement mechanism, carry out the measuring surface form of testee 4, the concrete steps of measuring method are:

Step one, testee 4 is placed in below grating 3, opens red, green, blue three line sources 1 simultaneously, produce secondary color Moire fringe on testee 4 surface, have certain phase-shift phase between assorted Moire fringe, then colourful CCD video camera 2 absorbs secondary color Moire fringe under single shot condition;

Step 2, is separated the secondary color Moire fringe of picked-up in a computer and forms monochromatic Moire fringe, just obtain the phase shift moire fringe figure for demodulation testee 4 surface topography;

Suppose A _k(x, y) is background, B _k(x, y) is modulation item, φ _k(x, y) is phase place, k=1, and 2,3 is time domain striped sequence number, then the bar graph light intensity absorbed can be expressed as respectively:

I _k(x,y)＝A _k(x,y)+B _k(x,y)cos[φ _k(x,y)]；

Step 3, by the data Regularization of step 2 gained, removes striped background and amplitude, eliminates color cross-talk to the impact of measuring; Then use primaries analytic approach to extract and measure phase place;

Described Regularization process is:

$\stackrel{\‾}{I}=\left[\begin{array}{cc}cos\left({\mathrm{\φ}}_1+{\mathrm{\δ}}_1\right)......cos\left({\mathrm{\φ}}_m+{\mathrm{\δ}}_m\right)& ......cos\left({\mathrm{\φ}}_n+{\mathrm{\δ}}_n\right)\\ \cos \left({\mathrm{\φ}}_1+{\mathrm{\δ}}_2\right)......cos\left({\mathrm{\φ}}_m+{\mathrm{\δ}}_m\right)& ......cos\left({\mathrm{\φ}}_n+{\mathrm{\δ}}_n\right)\\ \cos \left({\mathrm{\φ}}_1+{\mathrm{\δ}}_3\right)......\cos \left({\mathrm{\φ}}_m+{\mathrm{\δ}}_m\right)& ......\cos \left({\mathrm{\φ}}_n+{\mathrm{\δ}}_n\right)\end{array}\right],$ In formula, n is pixel number;

Step 4, uses de-packaging method to carry out phase unwrapping to the measurement phase place that step 3 is extracted;

Step 5, according to the phase place of measurement sensistivity S and expansion, carries out Phase-height mapping, completes measurement;

As continued to measure, repeat measuring surface form step.

By above-mentioned measuring method, can fully the advantageous feature such as the contactless measurement of full field of shadow Moire D profile detection and phase measurement high precision be combined, and the restriction of beyond tradition shadow Moire technical system in measuring process; To this, this patent proposes the phase shift shadow Moire three-dimensional sensing new technology based on red, green, blue (RGB) light source.Colored CCD is that under single shot, data quick sampling is given security, by arranging that light source position realizes secondary color More and stripe measurement phase-modulation, then light field standardization bar graph data are corrected, and develop high precision phase shift algorithm, become accurate phase de-packaging method and system calibrating technology, by thick and smart, absolute phase is mapped to measuring height space.

Content of the present invention is not limited to cited by embodiment, and the conversion of those of ordinary skill in the art by reading instructions of the present invention to any equivalence that technical solution of the present invention is taked, is claim of the present invention and contains.

Claims (5)

1. a shadow moire profilometry device, is characterized in that: described measurement mechanism comprises red, green, blue three line sources (1), colourful CCD video camera (2), a grating (3) and a precision displacement platform; Described red, green, blue three line sources (1) and colourful CCD video camera (2) conllinear be arranged at grating (3) side and parallel with grating face; Described grating (3) is arranged on precision displacement platform; Described red, green, blue three line sources (1) are arranged in colourful CCD video camera (2) side.

2. shadow moire profilometry device according to claim 1, is characterized in that: described precision displacement platform is manual precision displacement table or electric precision displacement platform.

3. shadow moire profilometry device according to claim 1, is characterized in that: described red, green, blue three line sources (1) are arranged in colourful CCD video camera (2) side at equal intervals.

4. the scaling method of a kind of shadow moire profilometry device as claimed in claim 1, is characterized in that: comprise the following steps:

Step one, testee (4) is placed in grating (3) below, open any one monochromatic source in red, green, blue three line sources (1), by the equidistant moving grating of precision displacement platform (3) several times, shooting and record phase shift bar graph wherein;

Step 2, use phase shift extraction algorithm determines the phase shift because moving grating (3) produces.

5. the measuring method of a kind of shadow moire profilometry device as claimed in claim 1, is characterized in that: comprise the following steps successively:

Step one, grating (3) is adjusted to initial position, testee (4) is placed in grating (3) below, open red, green, blue three line sources (1) simultaneously, produce secondary color Moire fringe on testee surface, then colourful CCD video camera (2) absorbs secondary color Moire fringe under single shot condition;

Step 2, is separated the secondary color Moire fringe of picked-up and forms monochromatic Moire fringe, obtain the phase shift moire fringe figure for demodulation testee (4) surface topography;

Step 3, by the data Regularization of step 2 gained, then uses primaries analytic approach to extract and measures phase place;

Step 4, uses de-packaging method to carry out phase unwrapping to the measurement phase place that step 3 is extracted;

Step 5, according to the phase place of measurement sensistivity and expansion, carries out Phase-height mapping, completes measurement.